release 3.6.2

- OpenRocket
- Warteschlangensimulator
- Nortantis
- QStudio
- Launch4j

.github/workflows/ci.yml

@@ -9,49 +9,40 @@ on:
       - '*'
     tags:
       - '[0-9]*'
+    paths-ignore:
+      - '**.md'
+      - '.*'
+      - '**/.settings/**'
+      - 'flatlaf-core/svg/**'
+      - 'flatlaf-testing/dumps/**'
+      - 'flatlaf-testing/misc/**'
+      - 'images/**'
 
 jobs:
   build:
+    name: build (11)
     runs-on: ubuntu-latest
 
-    strategy:
-      matrix:
-        # test against
-        # - Java 8 (minimum requirement)
-        # - Java LTS versions (11, 17, ...)
-        # - lastest Java version(s)
-        java:
-          - 8
-          - 11  # LTS
-          - 17  # LTS
-        toolchain: [""]
-        include:
-          - java: 17
-            toolchain: 21  # latest
-
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
-      - uses: gradle/wrapper-validation-action@v1
-        if: matrix.java == '8'
+      - uses: gradle/actions/wrapper-validation@v4
 
-      - name: Setup Java ${{ matrix.java }}
-        uses: actions/setup-java@v3
+      - name: Setup Java 11
+        uses: actions/setup-java@v4
         with:
-          java-version: ${{ matrix.java }}
-          distribution: temurin  # Java 8, 11 and 17 are pre-installed on ubuntu-latest
+          java-version: 11
+          distribution: temurin  # pre-installed on ubuntu-latest
           cache: gradle
 
       - name: Check with Error Prone
-        if: matrix.java == '11'
-        run: ./gradlew errorprone clean -Dtoolchain=${{ matrix.toolchain }}
+        run: ./gradlew errorprone clean
 
       - name: Build with Gradle
-        run: ./gradlew build -Dtoolchain=${{ matrix.toolchain }}
+        run: ./gradlew build
 
       - name: Upload artifacts
-        uses: actions/upload-artifact@v3
-        if: matrix.java == '11'
+        uses: actions/upload-artifact@v4
         with:
           name: FlatLaf-build-artifacts
           path: |
@@ -61,86 +52,97 @@ jobs:
             !**/*-sources.jar
 
 
-  snapshot:
+  build-on:
     runs-on: ubuntu-latest
     needs: build
+    if: github.repository == 'JFormDesigner/FlatLaf'
+
+    strategy:
+      matrix:
+        # test against
+        # - Java 8 (minimum requirement)
+        # - Java LTS versions (11, 17, ...)
+        # - latest Java version(s)
+        java:
+          - 8
+          - 17  # LTS
+          - 21  # LTS
+        toolchain: [""]
+        include:
+          - java: 21
+            toolchain: 25  # LTS
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Java ${{ matrix.java }}
+        uses: actions/setup-java@v4
+        with:
+          java-version: ${{ matrix.java }}
+          distribution: temurin  # Java 8, 11, 17 and 21 are pre-installed on ubuntu-latest
+          cache: gradle
+
+      - name: Build with Gradle
+        run: ./gradlew build -Dtoolchain=${{ matrix.toolchain }}
+
+
+  snapshot:
+    runs-on: ubuntu-latest
+    needs: build-on
     if: |
       github.event_name == 'push' &&
       (github.ref == 'refs/heads/main' || startsWith( github.ref, 'refs/heads/develop-' )) &&
       github.repository == 'JFormDesigner/FlatLaf'
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Setup Java 11
-        uses: actions/setup-java@v3
+        uses: actions/setup-java@v4
         with:
           java-version: 11
           distribution: temurin  # pre-installed on ubuntu-latest
           cache: gradle
 
-      - name: Publish snapshot to oss.sonatype.org
-        run: ./gradlew publish :flatlaf-theme-editor:build -PskipFonts -Dorg.gradle.internal.publish.checksums.insecure=true -Dorg.gradle.parallel=false
+      - name: Publish snapshot to Sonatype Central
+        run: ./gradlew publish -PskipFonts -Dorg.gradle.internal.publish.checksums.insecure=true -Dorg.gradle.parallel=false
         env:
-          OSSRH_USERNAME: ${{ secrets.OSSRH_USERNAME }}
-          OSSRH_PASSWORD: ${{ secrets.OSSRH_PASSWORD }}
-
-      - name: Upload theme editor
-        uses: sebastianpopp/ftp-action@releases/v2
-        with:
-          host: ${{ secrets.FTP_SERVER }}
-          user: ${{ secrets.FTP_USERNAME }}
-          password: ${{ secrets.FTP_PASSWORD }}
-          forceSsl: true
-          localDir: "flatlaf-theme-editor/build/libs"
-          remoteDir: "snapshots"
-          options: "--only-newer --no-recursion --verbose=1"
+          SONATYPE_USERNAME: ${{ secrets.SONATYPE_USERNAME }}
+          SONATYPE_PASSWORD: ${{ secrets.SONATYPE_PASSWORD }}
 
 
   release:
     runs-on: ubuntu-latest
-    needs: build
+    needs: build-on
     if: |
       github.event_name == 'push' &&
       startsWith( github.ref, 'refs/tags/' ) &&
       github.repository == 'JFormDesigner/FlatLaf'
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Setup Java 11
-        uses: actions/setup-java@v3
+        uses: actions/setup-java@v4
         with:
           java-version: 11
           distribution: temurin  # pre-installed on ubuntu-latest
           cache: gradle
 
       - name: Release a new stable version to Maven Central
-        run: ./gradlew publish :flatlaf-demo:build :flatlaf-theme-editor:build -PskipFonts -Prelease -Dorg.gradle.parallel=false
+        run: ./gradlew publishToSonatype closeSonatypeStagingRepository :flatlaf-demo:build :flatlaf-theme-editor:build -PskipFonts -Prelease -Dorg.gradle.parallel=false
         env:
-          OSSRH_USERNAME: ${{ secrets.OSSRH_USERNAME }}
-          OSSRH_PASSWORD: ${{ secrets.OSSRH_PASSWORD }}
+          SONATYPE_USERNAME: ${{ secrets.SONATYPE_USERNAME }}
+          SONATYPE_PASSWORD: ${{ secrets.SONATYPE_PASSWORD }}
           SIGNING_KEY:      ${{ secrets.SIGNING_KEY }}
           SIGNING_PASSWORD: ${{ secrets.SIGNING_PASSWORD }}
 
-      - name: Upload demo
-        uses: sebastianpopp/ftp-action@releases/v2
-        with:
-          host: ${{ secrets.FTP_SERVER }}
-          user: ${{ secrets.FTP_USERNAME }}
-          password: ${{ secrets.FTP_PASSWORD }}
-          forceSsl: true
-          localDir: "flatlaf-demo/build/libs"
-          remoteDir: "."
-          options: "--only-newer --no-recursion --verbose=1"
+      - name: Install lftp
+        run: sudo apt-get -y install lftp
 
-      - name: Upload theme editor
-        uses: sebastianpopp/ftp-action@releases/v2
-        with:
-          host: ${{ secrets.FTP_SERVER }}
-          user: ${{ secrets.FTP_USERNAME }}
-          password: ${{ secrets.FTP_PASSWORD }}
-          forceSsl: true
-          localDir: "flatlaf-theme-editor/build/libs"
-          remoteDir: "."
-          options: "--only-newer --no-recursion --verbose=1"
+      - name: Upload demo and theme editor
+        run: >
+          lftp -c "set ftp:ssl-force true;
+            open -u ${{ secrets.FTP_USERNAME }},${{ secrets.FTP_PASSWORD }} ${{ secrets.FTP_SERVER }};
+            mput flatlaf-demo/build/libs/flatlaf-demo-*.jar;
+            mput flatlaf-theme-editor/build/libs/flatlaf-theme-editor-*.jar"

.github/workflows/fonts.yml

@@ -13,6 +13,8 @@ on:
             - 'flatlaf-fonts/**'
             - '.github/workflows/fonts.yml'
             - 'gradle/wrapper/gradle-wrapper.properties'
+            - '!**.md'
+            - '!**/.settings/**'
 
 jobs:
     Fonts:
@@ -30,10 +32,10 @@ jobs:
             github.repository == 'JFormDesigner/FlatLaf'
 
         steps:
-            - uses: actions/checkout@v3
+            - uses: actions/checkout@v4
 
             - name: Setup Java 11
-              uses: actions/setup-java@v3
+              uses: actions/setup-java@v4
               with:
                   java-version: 11
                   distribution: temurin  # pre-installed on ubuntu-latest
@@ -43,18 +45,18 @@ jobs:
               run: ./gradlew :flatlaf-fonts-${{ matrix.font }}:build
               if: startsWith( github.ref, format( 'refs/tags/fonts/{0}-', matrix.font ) ) != true
 
-            - name: Publish snapshot to oss.sonatype.org
+            - name: Publish snapshot to Sonatype Central
               run: ./gradlew :flatlaf-fonts-${{ matrix.font }}:publish -Dorg.gradle.internal.publish.checksums.insecure=true
               env:
-                  OSSRH_USERNAME: ${{ secrets.OSSRH_USERNAME }}
-                  OSSRH_PASSWORD: ${{ secrets.OSSRH_PASSWORD }}
+                  SONATYPE_USERNAME: ${{ secrets.SONATYPE_USERNAME }}
+                  SONATYPE_PASSWORD: ${{ secrets.SONATYPE_PASSWORD }}
               if: github.ref == 'refs/heads/main' || startsWith( github.ref, 'refs/heads/develop-' )
 
             - name: Release a new stable version to Maven Central
               run: ./gradlew :flatlaf-fonts-${{ matrix.font }}:build :flatlaf-fonts-${{ matrix.font }}:publish -Prelease
               env:
-                  OSSRH_USERNAME: ${{ secrets.OSSRH_USERNAME }}
-                  OSSRH_PASSWORD: ${{ secrets.OSSRH_PASSWORD }}
+                  SONATYPE_USERNAME: ${{ secrets.SONATYPE_USERNAME }}
+                  SONATYPE_PASSWORD: ${{ secrets.SONATYPE_PASSWORD }}
                   SIGNING_KEY:      ${{ secrets.SIGNING_KEY }}
                   SIGNING_PASSWORD: ${{ secrets.SIGNING_PASSWORD }}
               if: startsWith( github.ref, format( 'refs/tags/fonts/{0}-', matrix.font ) )

.github/workflows/natives.yml

@@ -13,24 +13,36 @@ on:
             - 'flatlaf-natives/**'
             - '.github/workflows/natives.yml'
             - 'gradle/wrapper/gradle-wrapper.properties'
+            - '!**.md'
+            - '!**/.settings/**'
 
 jobs:
     Natives:
         strategy:
             matrix:
                 os:
-                    - windows
-                    - ubuntu
+                    - windows-latest
+                    - macos-latest
+                    - ubuntu-latest
+                    - ubuntu-24.04-arm
 
-        runs-on: ${{ matrix.os }}-latest
+        runs-on: ${{ matrix.os }}
 
         steps:
-            - uses: actions/checkout@v3
+            - uses: actions/checkout@v4
 
-            - uses: gradle/wrapper-validation-action@v1
+            - uses: gradle/actions/wrapper-validation@v4
+
+            - name: install libxt-dev
+              if: matrix.os == 'ubuntu-latest' || matrix.os == 'ubuntu-24.04-arm'
+              run: sudo apt install libxt-dev
+
+            - name: install g++-aarch64-linux-gnu
+              if: matrix.os == 'ubuntu-latest'
+              run: sudo apt install g++-aarch64-linux-gnu
 
             - name: Setup Java 11
-              uses: actions/setup-java@v3
+              uses: actions/setup-java@v4
               with:
                   java-version: 11
                   distribution: temurin
@@ -42,7 +54,7 @@ jobs:
               run: ./gradlew build-natives --no-daemon
 
             - name: Upload artifacts
-              uses: actions/upload-artifact@v3
+              uses: actions/upload-artifact@v4
               with:
                   name: FlatLaf-natives-build-artifacts-${{ matrix.os }}
                   path: |

.github/workflows/pr-snapshots.yml

@@ -0,0 +1,37 @@
+# https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions
+
+name: PR Snapshots
+
+on:
+  pull_request:
+    paths-ignore:
+      - '**.md'
+      - '.*'
+      - '**/.settings/**'
+      - 'flatlaf-core/svg/**'
+      - 'flatlaf-testing/dumps/**'
+      - 'flatlaf-testing/misc/**'
+      - 'images/**'
+
+jobs:
+  snapshot:
+    runs-on: ubuntu-latest
+    if: github.repository == 'JFormDesigner/FlatLaf'
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Java 11
+        uses: actions/setup-java@v4
+        with:
+          java-version: 11
+          distribution: temurin  # pre-installed on ubuntu-latest
+          cache: gradle
+
+      - name: Publish PR snapshot to Sonatype Central
+        run: >
+          ./gradlew publish -PskipFonts -Dorg.gradle.internal.publish.checksums.insecure=true -Dorg.gradle.parallel=false
+          -Pgithub.event.pull_request.number=${{ github.event.pull_request.number }}
+        env:
+          SONATYPE_USERNAME: ${{ secrets.SONATYPE_USERNAME }}
+          SONATYPE_PASSWORD: ${{ secrets.SONATYPE_PASSWORD }}

.gitignore

@@ -5,6 +5,7 @@ build/
 .project
 .settings/
 .idea/
+.consulo/
 out/
 *.iml
 *.ipr

CHANGELOG.md

@@ -1,6 +1,435 @@
 FlatLaf Change Log
 ==================
 
+## 3.6.2
+
+#### New features and improvements
+
+- If using `FlatLaf.registerCustomDefaultsSource( "com.myapp.themes" )` and
+  named Java modules, it is no longer necessary to add `opens com.myapp.themes;`
+  to `module-info.java`. (issue #1026)
+- Extras: Made animated theme change (class `FlatAnimatedLafChange`) smoother.
+
+#### Fixed bugs
+
+- Tree and List: Fixed painting of rounded drop backgrounds. (issue #1023)
+- Popup: Showing tooltip in inactive window brought that window to front (made
+  it active) and potentially hid the previously active window. (issue #1037)
+- Popup: No longer reuse popup windows for menus to avoid immediately closing
+  dialogs on ChromeOS. (issue #1029)
+- macOS: Fixed window "flashing" when switching from a light to a dark theme (or
+  vice versa). Especially when using animated theme changer (see
+  [FlatLaf Extras](flatlaf-extras)).
+
+#### Incompatibilities
+
+- FlatLaf properties files are now loaded using the UTF-8 character encoding
+  instead of ISO 8859-1. In usual properties files you will not notice any
+  difference because they use only ASCII characters, but if you've put localized
+  (non-English) texts (e.g. German umlauts) into your properties files, you need
+  to convert them to UTF-8. Properties files created with the FlatLaf Theme
+  Editor already use UTF-8, including in older versions. (issue #1031)
+
+
+## 3.6.1
+
+- Extras: Support JSVG 2.0.0. Minimum JSVG version is now 1.6.0. (issue #997)
+- FlatLaf window decorations (Windows 10/11 only): Improved diagonal window
+  resizing on top-left and top-right window corners. Top window resize area now
+  also covers iconify/maximize/close buttons. (issue #1015)
+- ToggleButton: Styling `selectedForeground` did not work if `foreground` is
+  also styled. (issue #1017)
+- JideSplitButton: Fixed updating popup when switching theme. (issue #1000)
+- IntelliJ Themes: Fixed logging false errors when loading 3rd party
+  `.theme.json` files. (issue #990)
+- Linux: Popups appeared in wrong position on multi-screen setup if primary
+  display is located below or right to secondary display. (see
+  [NetBeans issue #8532](https://github.com/apache/netbeans/issues/8532))
+- macOS: Fixed popup flickering after theme change. (issue #1009)
+- macOS with JetBrains Runtime: Fixed sometimes empty popups. (issue #1019)
+
+
+## 3.6
+
+#### New features and improvements
+
+- macOS: Re-enabled rounded popup border (see PR #772) on macOS 14.4+ (was
+  disabled in 3.5.x).
+- Increased contrast of text for better readability: (PR #972; issue #762)
+  - In **FlatLaf Dark**, **FlatLaf Darcula** and many dark IntelliJ themes, made
+    all text colors brighter.
+  - In **FlatLaf Light**, **FlatLaf IntelliJ** and many light IntelliJ themes,
+    made disabled text colors slightly darker.
+  - In **FlatLaf macOS Light**, made disabled text colors darker.
+  - In **FlatLaf macOS Dark**, made text colors of "default" button and selected
+    ToggleButton lighter.
+- CheckBox: Support styling indeterminate state of
+  [tri-state check boxes](https://www.javadoc.io/doc/com.formdev/flatlaf-extras/latest/com/formdev/flatlaf/extras/components/FlatTriStateCheckBox.html).
+  (PR #936; issue #919)
+- List: Support for alternate row highlighting. (PR #939)
+- Tree: Support for alternate row highlighting. (PR #903)
+- Tree: Support wide cell renderer. (issue #922)
+- ScrollBar: Use rounded thumb also on Windows (as on macOS and Linux) and made
+  thumb slightly darker/lighter. (issue #918)
+- Extras: `FlatSVGIcon` color filters now can access painting component to
+  implement component state based color mappings. (issue #906)
+- Linux:
+  - Rounded iconify/maximize/close buttons if using FlatLaf window decorations.
+    (PR #971)
+  - Added `libflatlaf-linux-arm64.so` for Linux on ARM64. (issue #899)
+  - Use X11 window manager events to resize window, if FlatLaf window
+    decorations are enabled. This gives FlatLaf windows a more "native" feeling.
+    (issue #866)
+- IntelliJ Themes:
+  - Updated to latest versions and fixed various issues.
+  - Support customizing through properties files. (issue #824)
+- SwingX: Support `JXTipOfTheDay` component. (issue #980)
+- Support key prefixes for Linux desktop environments (e.g. `[gnome]`, `[kde]`
+  or `[xfce]`) in properties files. (issue #974)
+- Support custom key prefixes (e.g. `[win10]` or `[test]`) in properties files.
+  (issue #649)
+- Support multi-prefixed keys (e.g. `[dark][gnome]TitlePane.buttonBackground`).
+  The value is only used if all prefixes match current platform/theme.
+- Support new component border color to indicate success state (set client
+  property `JComponent.outline` to `success`). (PR #982, issue #945)
+- Fonts: Updated **Inter** to
+  [v4.1](https://github.com/rsms/inter/releases/tag/v4.1).
+
+#### Fixed bugs
+
+- Button: Fixed background and foreground colors for `borderless` and
+  `toolBarButton` style default buttons (`JButton.isDefaultButton()` is `true`).
+  (issue #947)
+- FileChooser: Improved performance when navigating to large directories with
+  thousands of files. (issue #953)
+- PopupFactory: Fixed NPE on Windows 10 when `owner` is `null`. (issue #952)
+- Popup: On Windows 10, drop shadow of heavy-weight popup was not updated if
+  popup moved/resized. (issue #942)
+- FlatLaf window decorations:
+  - Minimize and maximize icons were not shown for custom scale factors less
+    than 100% (e.g. `-Dflatlaf.uiScale=75%`). (issue #951)
+  - Linux: Fixed occasional maximizing of window when single-clicking the
+    window's title bar. (issue #637)
+- Styling: MigLayout visual padding was not updated after applying style to
+  Button, ComboBox, Spinner, TextField (and subclasses) and ToggleButton. (issue
+  #965)
+- Linux: Popups (menus and combobox lists) were not hidden when window is moved,
+  resized, maximized, restored, iconified or switched to another window. (issue
+  #962)
+- Fixed loading FlatLaf UI delegate classes when using FlatLaf in special
+  application where multiple class loaders are involved. E.g. in Eclipse plugin
+  or in LibreOffice extension. (issues #955 and #851)
+- HTML: Fixed rendering of `<hr noshade>` in dark themes. (issue #932)
+- TextComponents: `selectAllOnFocusPolicy` related changes:
+  - No longer select all text if selection (or caret position) was changed by
+    application and `selectAllOnFocusPolicy` is `once` (the default). (issue
+    #983)
+  - FormattedTextField and Spinner: `selectAllOnFocusPolicy = once` behaves now
+    as `always` (was `never` before), which means that all text is selected when
+    component gains focus. This is because of special behavior of
+    `JFormattedTextField` that did not allow implementation of `once`.
+  - Client property `JTextField.selectAllOnFocusPolicy` now also works on
+    (editable) `JComboBox` and on `JSpinner`.
+  - Added client property `JTextField.selectAllOnMouseClick` to override UI
+    property `TextComponent.selectAllOnMouseClick`. (issue #961)
+  - For `selectAllOnMouseClick = true`, clicking with the mouse into the text
+    field, to focus it, now always selects all text, even if
+    `selectAllOnFocusPolicy` is `once`.
+
+#### Incompatibilities
+
+- IntelliJ Themes:
+  - Theme prefix in `IntelliJTheme$ThemeLaf.properties` changed from
+    `[theme-name]` to `{theme-name}`.
+  - Renamed classes in package
+    `com.formdev.flatlaf.intellijthemes.materialthemeuilite` from `Flat<theme>`
+    to `FlatMT<theme>`.
+  - Removed `Gruvbox Dark Medium` and `Gruvbox Dark Soft` themes.
+- Prefixed keys in properties files (e.g. `[dark]Button.background` or
+  `[win]Button.arc`) are now handled earlier than before. In previous versions,
+  prefixed keys always had higher priority than unprefixed keys and did always
+  overwrite unprefixed keys. Now prefixed keys are handled in same order as
+  unprefixed keys, which means that if a key is prefixed and unprefixed (e.g.
+  `[win]Button.arc` and `Button.arc`), the one which is last specified in
+  properties file is used.\
+  Following worked in previous versions, but now `Button.arc` is always `6`:
+  ~~~properties
+  [win]Button.arc = 12
+  Button.arc = 6
+  ~~~
+  This works in new (and old) versions:
+  ~~~properties
+  Button.arc = 6
+  [win]Button.arc = 12
+  ~~~
+
+
+## 3.5.4
+
+#### Fixed bugs
+
+- HTML: Fixed NPE when using HTML text on a component with `null` font. (issue
+  #930; PR #931; regression in 3.5)
+- Linux: Fixed NPE when using FlatLaf window decorations and switching theme.
+  (issue #933; regression in 3.5.3)
+
+
+## 3.5.3
+
+#### Fixed bugs
+
+- HTML: Fixed wrong rendering if HTML text contains `<style>` tag with
+  attributes (e.g. `<style type='text/css'>`). (issue #905; regression in 3.5.1)
+- FlatLaf window decorations:
+  - Windows: Fixed possible deadlock with TabbedPane in window title area in
+    "full window content" mode. (issue #909)
+  - Windows: Fixed wrong layout in maximized frame after changing screen scale
+    factor. (issue #904)
+  - Linux: Fixed continuous cursor toggling between resize and standard cursor
+    when resizing window. (issue #907)
+  - Fixed sometimes broken window moving with SplitPane in window title area in
+    "full window content" mode. (issue #926)
+- Popup: On Windows 10, fixed misplaced popup drop shadow. (issue #911;
+  regression in 3.5)
+- Popup: Fixed NPE if `GraphicsConfiguration` is `null` on Windows. (issue #921)
+- Theme Editor: Fixed using color picker on secondary screen.
+- Fixed detection of Windows 11 if custom exe launcher does not specify Windows
+  10+ compatibility in application manifest. (issue #916)
+- Linux: Fixed slightly different font size (or letter width) used to paint HTML
+  text when default font family is _Cantarell_ (e.g. on Fedora). (issue #912)
+
+#### Other Changes
+
+- Class `FlatPropertiesLaf` now supports FlatLaf macOS themes as base themes.
+
+
+## 3.5.2
+
+#### Fixed bugs
+
+- Windows: Fixed repaint issues (ghosting) on some systems (probably depending
+  on graphics card/driver). This is done by setting Java system property
+  `sun.java2d.d3d.onscreen` to `false` (but only if `sun.java2d.d3d.onscreen`,
+  `sun.java2d.d3d` and `sun.java2d.noddraw` are not yet set), which disables
+  usage of Windows Direct3D (DirectX) onscreen surfaces. Component rendering
+  still uses Direct3D. (issue #887)
+- FlatLaf window decorations:
+  - Iconify/maximize/close buttons did not fill whole title bar height, if some
+    custom component in menu bar increases title bar height. (issue #897)
+  - Windows: Fixed possible application freeze when using custom component that
+    overrides `Component.contains(int x, int y)` and invokes
+    `SwingUtilities.convertPoint()` (or similar) from the overridden method.
+    (issue #878)
+- TextComponents: Fixed too fast scrolling in multi-line text components when
+  using touchpads (e.g. on macOS). (issue #892)
+- ToolBar: Fixed endless loop if button in Toolbar has focus and is made
+  invisible. (issue #884)
+
+#### Other Changes
+
+- FlatLaf window decorations: Added client property `JRootPane.titleBarHeight`
+  to allow specifying a (larger) preferred height for the title bar. (issue
+  #897)
+- Added system property `flatlaf.useRoundedPopupBorder` to allow disabling
+  native rounded popup borders on Windows 11 and macOS. On macOS 14.4+, where
+  rounded popup borders are disabled since FlatLaf 3.5 because of occasional
+  problems, you can use this to enable rounded popup borders (at your risk).
+
+
+## 3.5.1
+
+#### Fixed bugs
+
+- HTML: Fixed occasional cutoff wrapped text when using multi-line text in HTML
+  tags `<h1>`...`<h6>`, `<code>`, `<kbd>`, `<big>`, `<small>` or `<samp>`.
+  (issue #873; regression in 3.5)
+- Popup: Fixed `UnsupportedOperationException: PERPIXEL_TRANSLUCENT translucency
+  is not supported` exception on Haiku OS when showing popup (partly) outside of
+  window. (issue #869)
+- HiDPI: Fixed occasional wrong repaint areas when using
+  `HiDPIUtils.installHiDPIRepaintManager()`. (see PR #864)
+- Added system property `flatlaf.useSubMenuSafeTriangle` to allow disabling
+  submenu safe triangle (PR #490) for
+  [SWTSwing](https://github.com/Chrriis/SWTSwing). (issue #870)
+
+
+## 3.5
+
+#### New features and improvements
+
+- Table: Support rounded selection. (PR #856)
+- Button and ToggleButton: Added border colors for pressed and selected states.
+  (issue #848)
+- Label: Support painting background with rounded corners. (issue #842)
+- Popup: Fixed flicker of popups (e.g. tooltips) while they are moving (e.g.
+  following mouse pointer). (issues #832 and #672)
+- FileChooser: Wrap shortcuts in scroll pane. (issue #828)
+- Theme Editor: On macOS, use larger window title bar. (PR #779)
+
+#### Fixed bugs
+
+- macOS: Disabled rounded popup border (see PR #772) on macOS 14.4+ because it
+  may freeze the application and crash the macOS WindowServer process (reports
+  vary from Finder restarts to OS restarts). This is a temporary change until a
+  solution is found. See NetBeans issues
+  [apache/netbeans#7560](https://github.com/apache/netbeans/issues/7560#issuecomment-2226439215)
+  and
+  [apache/netbeans#6647](https://github.com/apache/netbeans/issues/6647#issuecomment-2070124442).
+- FlatLaf window decorations: Window top border on Windows 10 in "full window
+  content" mode was not fully repainted when activating or deactivating window.
+  (issue #809)
+- Button and ToggleButton: UI properties `[Toggle]Button.selectedForeground` and
+  `[Toggle]Button.pressedForeground` did not work for HTML text. (issue #848)
+- HTML: Fixed font sizes for HTML tags `<h1>`...`<h6>`, `<code>`, `<kbd>`,
+  `<big>`, `<small>` and `<samp>` in HTML text for components Button, CheckBox,
+  RadioButton, MenuItem (and subclasses), JideLabel, JideButton, JXBusyLabel and
+  JXHyperlink. Also fixed for Label and ToolTip if using Java 11+.
+- ScrollPane: Fixed/improved border painting at 125% - 175% scaling to avoid
+  different border thicknesses. (issue #743)
+- Table: Fixed painting of alternating rows below table if auto-resize mode is
+  `JTable.AUTO_RESIZE_OFF` and table width is smaller than scroll pane (was not
+  updated when table width changed and was painted on wrong side in
+  right-to-left component orientation).
+- Theme Editor: Fixed occasional empty window on startup on macOS.
+- FlatLaf window decorations: Fixed black line sometimes painted on top of
+  (native) window border on Windows 11. (issue #852)
+- HiDPI: Fixed incomplete component paintings at 125% or 175% scaling on Windows
+  where sometimes a 1px wide area at the right or bottom component edge is not
+  repainted. E.g. ScrollPane focus indicator border. (issues #860 and #582)
+
+#### Incompatibilities
+
+- ProgressBar: Log warning (including stack trace) when uninstalling
+  indeterminate progress bar UI or using `JProgressBar.setIndeterminate(false)`
+  not on AWT thread, because this may throw NPE in `FlatProgressBarUI.paint()`.
+  (issues #841 and #830)
+- Panel: Rounded background of panel with rounded corners is now painted even if
+  panel is not opaque. (issue #840)
+
+
+## 3.4.1
+
+#### Fixed bugs
+
+- SplitPane: Update divider when client property `JSplitPane.expandableSide`
+  changed.
+- TabbedPane: Fixed swapped back and forward scroll buttons when using
+  `TabbedPane.scrollButtonsPlacement = trailing` (regression in FlatLaf 3.3).
+- Fixed missing window top border on Windows 10 in "full window content" mode.
+  (issue #809)
+- Extras:
+  - `FlatSVGIcon` color filters now support linear gradients. (PR #817)
+  - `FlatSVGIcon`: Use log level `CONFIG` instead of `SEVERE` and allow
+    disabling logging. (issue #823)
+  - Added support for `JSplitPane.expandableSide` client property to
+    `FlatSplitPane`.
+- Native libraries: Added API version check to test whether native library
+  matches the JAR (bad builds could e.g. ship a newer JAR with an older
+  incompatible native library) and to test whether native methods can be invoked
+  (some security software allows loading native library but blocks method
+  invocation).
+- macOS: Fixed crash when running in WebSwing. (issue #826; regression in 3.4)
+
+#### Incompatibilities
+
+- File names of custom properties files for nested Laf classes now must include
+  name of enclosing class name. E.g. nested Laf class `IntelliJTheme.ThemeLaf`
+  used `ThemeLaf.properties` in previous versions, but now needs to be named
+  `IntelliJTheme$ThemeLaf.properties`.
+
+
+## 3.4
+
+#### New features and improvements
+
+- FlatLaf window decorations (Windows 10/11 and Linux): Support "full window
+  content" mode, which allows you to extend the content into the window title
+  bar. (PR #801)
+- macOS: Support larger window title bar close/minimize/zoom buttons spacing in
+  [full window content](https://www.formdev.com/flatlaf/macos/#full_window_content)
+  mode and introduced "buttons placeholder". (PR #779)
+- Native libraries:
+  - System property `flatlaf.nativeLibraryPath` now supports loading native
+    libraries named the same as on Maven central.
+  - Published `flatlaf-<version>-no-natives.jar` to Maven Central. This JAR is
+    equal to `flatlaf-<version>.jar`, except that it does not contain the
+    FlatLaf native libraries. The Maven "classifier" to use this JAR is
+    `no-natives`. You need to distribute the FlatLaf native libraries with your
+    application.
+    See https://www.formdev.com/flatlaf/native-libraries/ for more details.
+  - Improved log messages for loading fails.
+- Fonts: Updated **Inter** to
+  [v4.0](https://github.com/rsms/inter/releases/tag/v4.0).
+- Table: Select all text in cell editor when starting editing using `F2` key on
+  Windows or Linux. (issue #652)
+
+#### Fixed bugs
+
+- macOS: Setting window background (of undecorated window) to translucent color
+  (alpha < 255) did not show the window translucent. (issue #705)
+- JIDE CommandMenuBar: Fixed `ClassCastException` when JIDE command bar displays
+  `JideMenu` in popup. (PR #794)
+
+
+## 3.3
+
+#### New features and improvements
+
+- macOS (10.14+): Popups (`JPopupMenu`, `JComboBox`, `JToolTip`, etc.) now use
+  native macOS rounded borders. (PR #772; issue #715)
+- Native libraries: Added `libflatlaf-macos-arm64.dylib` and
+  `libflatlaf-macos-x86_64.dylib`. See also
+  https://www.formdev.com/flatlaf/native-libraries/.
+- ScrollPane: Support rounded border. (PR #713)
+- SplitPane: Support divider hover and pressed background colors. (PR #788)
+- TabbedPane: Support vertical tabs. (PR #758, issue #633)
+- TabbedPane: Paint rounded tab area background for rounded cards. (issue #717)
+- ToolBar: Added styling properties `separatorWidth` and `separatorColor`.
+
+#### Fixed bugs
+
+- Button and ToggleButton: Selected buttons did not use explicitly set
+  foreground color. (issue #756)
+- FileChooser: Catch NPE in Java 21 when getting icon for `.exe` files that use
+  default Windows exe icon. (see
+  [JDK-8320692](https://bugs.openjdk.org/browse/JDK-8320692))
+- OptionPane: Fixed styling custom panel background in `JOptionPane`. (issue
+  #761)
+- ScrollPane: Styling ScrollPane border properties did not work if view
+  component is a Table.
+- Table:
+  - Switching theme looses table grid and intercell spacing. (issues #733 and
+    #750)
+  - Fixed background of `boolean` columns when using alternating row colors.
+    (issue #780)
+  - Fixed border arc of components in complex table cell editors. (issue #786)
+- TableHeader:
+  - No longer temporary replace header cell renderer while painting. This avoids
+    a `StackOverflowError` in case that custom renderer does this too. (see
+    [NetBeans issue #6835](https://github.com/apache/netbeans/issues/6835)) This
+    also improves compatibility with custom table header implementations.
+  - Header cell renderer background/foreground colors were not restored after
+    hover if renderer uses `null` for background/foreground. (PR #790)
+- TabbedPane:
+  - Avoid unnecessary repainting whole tabbed pane content area when layouting
+    leading/trailing components.
+  - Avoid unnecessary repainting of selected tab on temporary changes.
+  - Fixed "endless" layouting and repainting when using nested tabbed panes (top
+    and bottom tab placement) and RSyntaxTextArea (with enabled line-wrapping)
+    as tab content. (see
+    [jadx issue #2030](https://github.com/skylot/jadx/issues/2030))
+- Fixed broken rendering after resizing window to minimum size and then
+  increasing size again. (issue #767)
+
+#### Incompatibilities
+
+- Removed support for JetBrains custom decorations, which required
+  [JetBrains Runtime](https://github.com/JetBrains/JetBrainsRuntime/wiki) (JBR)
+  8 or 11. It did not work for JBR 17. System property
+  `flatlaf.useJetBrainsCustomDecorations` is now ignored. **Note**: FlatLaf
+  window decorations continue to work with JBR.
+
+
 ## 3.2.5
 
 #### Fixed bugs
@@ -178,7 +607,6 @@ FlatLaf Change Log
   - Windows DLLs are now digitally signed with FormDev Software GmbH
     certificate.
 
-
 #### Fixed bugs
 
 - FlatLaf window decorations:
@@ -714,7 +1142,7 @@ FlatLaf Change Log
 - Native window decorations (Windows 10 only):
   - Fixed occasional application crash in `flatlaf-windows.dll`. (issue #357)
   - When window is initially shown, fill background with window background color
-    (instead of white), which avoids flickering in dark themes. (issue 339)
+    (instead of white), which avoids flickering in dark themes. (issue #339)
   - When resizing a window at the right/bottom edge, then first fill the new
     space with the window background color (instead of black) before the layout
     is updated.

README.md

@@ -33,14 +33,24 @@ FlatLaf can use 3rd party themes created for IntelliJ Platform (see
 Sponsors
 --------
 
+### Current Sponsors
+
+<a href="https://www.soptim.de/"><img src="https://www.formdev.com/flatlaf/sponsor/soptim.svg" width="200" alt="SOPTIM" title="SOPTIM - your expert in software solutions for the energy industry"></a>
+&nbsp; &nbsp; &nbsp; &nbsp;
+<a href="https://exocharts.com/"><img src="https://www.formdev.com/flatlaf/sponsor/Exocharts.png" width="200" alt="Exocharts" title="Exocharts - Professional Grade OrderFlow"></a>
+
+<!-- [![None Sponsors](images/none-sponsors.png)](https://www.formdev.com/flatlaf/sponsor/) -->
+
+[Become a Sponsor](https://www.formdev.com/flatlaf/sponsor/)
+
+### Previous Sponsors
+
 <a href="https://www.ej-technologies.com/"><img src="https://www.formdev.com/flatlaf/sponsor/ej-technologies.png" width="200" alt="ej-technologies" title="ej-technologies - Java APM, Java Profiler, Java Installer Builder"></a>
 &nbsp; &nbsp; &nbsp; &nbsp;
 <a href="https://www.dbvis.com/"><img src="https://www.formdev.com/flatlaf/sponsor/dbvisualizer.svg" width="200" alt="DbVisualizer" title="DbVisualizer - SQL Client and Editor"></a>
 &nbsp; &nbsp; &nbsp; &nbsp;
 <a href="https://www.dscsag.com/"><img src="https://www.formdev.com/flatlaf/sponsor/DSC.png" height="48" alt="DSC Software AG" title="DSC Software AG - Your Companion for Integrative PLM"></a>
 
-[Become a Sponsor](https://www.formdev.com/flatlaf/sponsor/)
-
 Demo
 ----
 
@@ -62,9 +72,9 @@ build script:
     artifactId:  flatlaf
     version:     (see button below)
 
-Otherwise download `flatlaf-<version>.jar` here:
+Otherwise, download `flatlaf-<version>.jar` here:
 
-[![Maven Central](https://maven-badges.herokuapp.com/maven-central/com.formdev/flatlaf/badge.svg?style=flat-square&color=007ec6)](https://maven-badges.herokuapp.com/maven-central/com.formdev/flatlaf)
+[![Maven Central](https://img.shields.io/maven-central/v/com.formdev/flatlaf?style=flat-square)](https://central.sonatype.com/artifact/com.formdev/flatlaf)
 
 See also
 [Native Libraries distribution](https://www.formdev.com/flatlaf/native-libraries/)
@@ -75,10 +85,10 @@ application.
 ### Snapshots
 
 FlatLaf snapshot binaries are available on
-[Sonatype OSSRH](https://oss.sonatype.org/content/repositories/snapshots/com/formdev/flatlaf/).
+[Sonatype Central](https://central.sonatype.com/service/rest/repository/browse/maven-snapshots/com/formdev/flatlaf/).
 To access the latest snapshot, change the FlatLaf version in your dependencies
-to `<version>-SNAPSHOT` (e.g. `0.27-SNAPSHOT`) and add the repository
-`https://oss.sonatype.org/content/repositories/snapshots/` to your build (see
+to `<version>-SNAPSHOT` (e.g. `3.7-SNAPSHOT`) and add the repository
+`https://central.sonatype.com/repository/maven-snapshots/` to your build (see
 [Maven](https://maven.apache.org/guides/mini/guide-multiple-repositories.html)
 and
 [Gradle](https://docs.gradle.org/current/userguide/declaring_repositories.html#sec:declaring_custom_repository)
@@ -141,7 +151,6 @@ details and downloads.
 Buzz
 ----
 
-- [What others say about FlatLaf on Twitter](https://twitter.com/search?f=live&q=flatlaf)
 - [FlatLaf 3.1 (and 3.0) announcement on Reddit](https://www.reddit.com/r/java/comments/12xgrsu/flatlaf_31_and_30_swing_look_and_feel/)
 - [FlatLaf 1.0 announcement on Reddit](https://www.reddit.com/r/java/comments/lsbcwe/flatlaf_10_swing_look_and_feel/)
 - [FlatLaf announcement on Reddit](https://www.reddit.com/r/java/comments/dl0hu3/flatlaf_flat_look_and_feel/)
@@ -177,11 +186,18 @@ Applications using FlatLaf
   relational data browsing tool
 - ![Hot](images/hot.svg) [MagicPlot](https://magicplot.com/) (**commercial**) -
   Software for nonlinear fitting, plotting and data analysis
-- ![New](images/new.svg) [Constellation](https://www.constellation-app.com/) -
-  Data Visualization and Analytics (based on NetBeans platform)
-- ![New](images/new.svg)
-  [Kafka Visualizer](https://github.com/kumait/kafkavisualizer) - Kafka GUI
+- [Constellation](https://www.constellation-app.com/) - Data Visualization and
+  Analytics (based on NetBeans platform)
+- [Kafka Visualizer](https://github.com/kumait/kafkavisualizer) - Kafka GUI
   client
+- ![New](images/new.svg)
+  [RedisFront](https://github.com/dromara/RedisFront/blob/master/README_EN.md) -
+  Cross-platform redis GUI
+- ![New](images/new.svg)
+  [Zettelkasten](https://github.com/Zettelkasten-Team/Zettelkasten) - knowledge
+  management tool
+- ![New](images/new.svg) [QStudio](https://www.timestored.com/qstudio/) - free
+  SQL editor
 
 ### Security
 
@@ -190,11 +206,9 @@ Applications using FlatLaf
 - ![Hot](images/hot.svg)
   [Burp Suite Professional and Community Edition](https://portswigger.net/burp/pro)
   (**commercial**) - the leading software for web security testing
-- ![New](images/new.svg)
-  [Ghidra](https://github.com/NationalSecurityAgency/ghidra) - a software
+- [Ghidra](https://github.com/NationalSecurityAgency/ghidra) - a software
   reverse engineering (SRE) framework
-- ![New](images/new.svg) [jadx](https://github.com/skylot/jadx) - Dex to Java
-  decompiler
+- [jadx](https://github.com/skylot/jadx) - Dex to Java decompiler
 - [BurpCustomizer](https://github.com/CoreyD97/BurpCustomizer) - adds more
   FlatLaf themes to Burp Suite
 - [Total Validator](https://www.totalvalidator.com/) (**commercial**) - checks
@@ -206,19 +220,26 @@ Applications using FlatLaf
 
 - [jclasslib bytecode viewer](https://github.com/ingokegel/jclasslib)
 - [KeyStore Explorer](https://keystore-explorer.org/)
-- ![New](images/new.svg)
-  [muCommander](https://github.com/mucommander/mucommander) - lightweight
+- [muCommander](https://github.com/mucommander/mucommander) - lightweight
   cross-platform file manager
-- ![New](images/new.svg) [Guiffy](https://www.guiffy.com/) (**commercial**) -
-  advanced cross-platform Diff/Merge
-- ![New](images/new.svg) [HashGarten](https://github.com/jonelo/HashGarten) -
-  cross-platform Swing GUI for Jacksum
+- [Guiffy](https://www.guiffy.com/) (**commercial**) - advanced cross-platform
+  Diff/Merge
+- [HashGarten](https://github.com/jonelo/HashGarten) - cross-platform Swing GUI
+  for Jacksum
 - [Pseudo Assembler IDE](https://github.com/tomasz-herman/PseudoAssemblerIDE) -
   IDE for Pseudo-Assembler
 - [Linotte](https://github.com/cpc6128/LangageLinotte) - French programming
   language created to learn programming
 - [lsfusion platform](https://github.com/lsfusion/platform) - information
   systems development platform
+- ![New](images/new.svg) [Consulo](https://github.com/consulo/consulo) - open
+  source cross-platform multi-language IDE (Java, .NET, JS, etc)
+- [Convertigo](https://github.com/convertigo/convertigo) - low code & no code
+  mobile & web platform
+- ![New](images/new.svg) [EduMIPS64](https://github.com/EduMIPS64/edumips64) -
+  visual MIPS64 CPU simulator
+- ![New](images/new.svg) [Launch4j](https://launch4j.sourceforge.net/) -
+  cross-platform Java executable wrapper
 
 ### Electrical
 
@@ -226,6 +247,11 @@ Applications using FlatLaf
   designing, simulating and explaining digital circuits
 - [Logisim-evolution](https://github.com/logisim-evolution/logisim-evolution) -
   Digital logic design tool and simulator
+- ![New](images/new.svg) [OpenPnP](https://github.com/openpnp/openpnp) - SMT
+  Pick and Place Hardware and Software
+- ![New](images/new.svg)
+  [TrainControl](https://github.com/bob123456678/TrainControl) - control Marklin
+  / Trix / DCC digital model train layout
 - [Makelangelo Software](https://github.com/MarginallyClever/Makelangelo-software) -
   for plotters, especially the wall-hanging polargraph
 - [GUIslice Builder](https://github.com/ImpulseAdventure/GUIslice-Builder) - GUI
@@ -240,8 +266,10 @@ Applications using FlatLaf
 
 - ![Hot](images/hot.svg) [jAlbum](https://jalbum.net/) (**commercial**) -
   creates photo album websites
-- ![New](images/new.svg) [MediathekView](https://mediathekview.de/) - search in
-  media libraries of various German broadcasters
+- [MediathekView](https://mediathekview.de/) - search in media libraries of
+  various German broadcasters
+- ![New](images/new.svg) [Pixelitor](https://github.com/lbalazscs/Pixelitor) -
+  image editor
 - [Cinecred](https://loadingbyte.com/cinecred/) - create beautiful film credit
   sequences
 - [tinyMediaManager](https://www.tinymediamanager.org/) (**commercial**) - a
@@ -257,19 +285,31 @@ Applications using FlatLaf
   from any webnovel and lightnovel site
 - [lectureStudio](https://www.lecturestudio.org/) - digitize your lectures with
   ease
+- ![New](images/new.svg) [Nortantis](https://jandjheydorn.com/nortantis) -
+  fantasy map generator and editor
 
-### Modelling
+### Modelling / Planning
 
-- ![New](images/new.svg) [Astah](https://astah.net/) (**commercial**) - create
-  UML, ER Diagram, Flowchart, Data Flow Diagram, Requirement Diagram, SysML
-  diagrams and more
+- ![New](images/new.svg) [OpenRocket](https://github.com/openrocket/openrocket) -
+  model-rocketry aerodynamics and trajectory simulation software
+- ![New](images/new.svg)
+  [Warteschlangensimulator](https://github.com/A-Herzog/Warteschlangensimulator) -
+  discrete-event stochastic simulator
+- ![New](images/new.svg) [Gephi](https://github.com/gephi/gephi) - the Open
+  Graph Viz Platform
+- [Astah](https://astah.net/) (**commercial**) - create UML, ER Diagram,
+  Flowchart, Data Flow Diagram, Requirement Diagram, SysML diagrams and more
 - [IGMAS+](https://www.gfz-potsdam.de/igmas) - Interactive Gravity and Magnetic
   Application System
+- ![New](images/new.svg) [StarPlan](https://www.progotec.de/) (**commercial**) -
+  die Stundenplan Software für Bildungseinrichtungen
+- ![New](images/new.svg) [SSPlot](https://github.com/babaissarkar/ssplot) -
+  plotting utility for plotting CSV data
 
 ### Documents
 
-- ![New](images/new.svg) [Big Faceless (BFO) PDF Viewer](https://bfo.com/)
-  (**commercial**) - Swing PDF Viewer
+- [Big Faceless (BFO) PDF Viewer](https://bfo.com/) (**commercial**) - Swing PDF
+  Viewer
 - [PDF Studio](https://www.qoppa.com/pdfstudio/) (**commercial**) - create,
   review and edit PDF documents
 - [XMLmind XML Editor](https://www.xmlmind.com/xmleditor/) (**commercial**)
@@ -287,6 +327,9 @@ Applications using FlatLaf
 
 ### Business / Legal
 
+- ![New](images/new.svg) ![Sponsor](images/sponsor.svg)
+  [Lisheane ERP](https://www.lisheane.ch/) (**commercial**) - backoffice
+  applikation
 - ![Sponsor](images/sponsor.svg)
   [j-lawyer](https://github.com/jlawyerorg/j-lawyer-org) - Kanzleisoftware
 - ![Sponsor](images/sponsor.svg) [Jeyla Studio](https://www.jeylastudio.com/) -
@@ -303,17 +346,20 @@ Applications using FlatLaf
 
 ### Messaging
 
-- ![New](images/new.svg) [Spark](https://github.com/igniterealtime/Spark) -
-  cross-platform IM client optimized for businesses and organizations
-- ![New](images/new.svg) [Chatty](https://github.com/chatty/chatty) - Twitch
-  Chat Client
+- [Spark](https://github.com/igniterealtime/Spark) - cross-platform IM client
+  optimized for businesses and organizations
+- [Chatty](https://github.com/chatty/chatty) - Twitch Chat Client
 
 ### Gaming
 
-- ![New](images/new.svg) ![Sponsor](images/sponsor.svg)
-  [BGBlitz](https://www.bgblitz.com/) (**commercial**) - professional Backgammon
-- ![New](images/new.svg) [MapTool](https://github.com/RPTools/maptool) - virtual
-  Tabletop for playing role-playing games
+- ![Sponsor](images/sponsor.svg) [BGBlitz](https://www.bgblitz.com/)
+  (**commercial**) - professional Backgammon
+- ![New](images/new.svg) [josé](https://peteschaefer.github.io/jose/) - a
+  graphical chess tool
+- ![New](images/new.svg) [MCreator](https://github.com/MCreator/MCreator) - make
+  Minecraft Java Edition mods, Minecraft Bedrock Edition Add-Ons, and data packs
+- [MapTool](https://github.com/RPTools/maptool) - virtual Tabletop for playing
+  role-playing games
 - [MegaMek](https://github.com/MegaMek/megamek),
   [MegaMekLab](https://github.com/MegaMek/megameklab) and
   [MekHQ](https://github.com/MegaMek/mekhq) - a sci-fi tabletop BattleTech
@@ -325,8 +371,7 @@ Applications using FlatLaf
 
 - [MooInfo](https://github.com/rememberber/MooInfo) - visual implementation of
   OSHI, to view information about the system and hardware
-- ![New](images/new.svg)
-  [Linux Task Manager (LTM)](https://github.com/ajee10x/LTM-LinuxTaskManager) -
+- [Linux Task Manager (LTM)](https://github.com/ajee10x/LTM-LinuxTaskManager) -
   GUI for monitoring and managing various aspects of a Linux system
 - [Rest Suite](https://github.com/supanadit/restsuite) - Rest API testing
 - [SpringRemote](https://github.com/HaleyWang/SpringRemote) - remote Linux SSH
@@ -335,6 +380,8 @@ Applications using FlatLaf
   easy
 - [Android Tool](https://github.com/fast-geek/Android-Tool) - makes popular adb
   and fastboot commands easier to use
+- ![New](images/new.svg) [Termora](https://github.com/TermoraDev/termora) -
+  Terminal emulator and SSH client
 
 ### Miscellaneous
 

build.gradle.kts

@@ -16,8 +16,15 @@
 
 import net.ltgt.gradle.errorprone.errorprone
 
+group = "com.formdev"
 version = property( if( hasProperty( "release" ) ) "flatlaf.releaseVersion" else "flatlaf.developmentVersion" ) as String
 
+// for PR snapshots change version to 'PR-<pr_number>-SNAPSHOT'
+val pullRequestNumber = findProperty( "github.event.pull_request.number" )
+if( pullRequestNumber != null )
+	version = "PR-${pullRequestNumber}-SNAPSHOT"
+
+
 allprojects {
 	version = rootProject.version
 
@@ -43,6 +50,7 @@ println()
 
 
 plugins {
+	alias( libs.plugins.gradle.nexus.publish.plugin )
 	alias( libs.plugins.errorprone ) apply false
 }
 
@@ -137,3 +145,20 @@ allprojects {
 		}
 	}
 }
+
+nexusPublishing {
+	repositories {
+		sonatype {
+			// see https://central.sonatype.org/publish/publish-portal-ossrh-staging-api/
+			nexusUrl = uri( "https://ossrh-staging-api.central.sonatype.com/service/local/" )
+			snapshotRepositoryUrl = uri( "https://central.sonatype.com/repository/maven-snapshots/" )
+
+			// get from gradle.properties
+			val sonatypeUsername: String? by project
+			val sonatypePassword: String? by project
+
+			username = System.getenv( "SONATYPE_USERNAME" ) ?: sonatypeUsername
+			password = System.getenv( "SONATYPE_PASSWORD" ) ?: sonatypePassword
+		}
+	}
+}

buildSrc/src/main/java/ReorderJarEntries.java

@@ -45,7 +45,7 @@ public class ReorderJarEntries
 			// 1st pass: copy .properties files
 			copyFiles( zipOutStream, jarFile, name -> name.endsWith( ".properties" ) );
 
-			// 2st pass: copy other files
+			// 2nd pass: copy other files
 			copyFiles( zipOutStream, jarFile, name -> !name.endsWith( ".properties" ) );
 		}
 

buildSrc/src/main/kotlin/flatlaf-cpp-library.gradle.kts

@@ -27,7 +27,7 @@ library {
 		}
 		with( linkTask.get() ) {
 			if( name.contains( "Release" ) )
-				debuggable.set( false )
+				debuggable = false
 		}
 	}
 }

buildSrc/src/main/kotlin/flatlaf-publish.gradle.kts

@@ -44,34 +44,34 @@ publishing {
 
 			pom {
 				afterEvaluate {
-					this@pom.name.set( extension.name )
-					this@pom.description.set( extension.description )
+					this@pom.name = extension.name
+					this@pom.description = extension.description
 				}
-				url.set( "https://github.com/JFormDesigner/FlatLaf" )
+				url = "https://github.com/JFormDesigner/FlatLaf"
 
 				licenses {
 					license {
-						name.set( "The Apache License, Version 2.0" )
-						url.set( "https://www.apache.org/licenses/LICENSE-2.0.txt" )
+						name = "The Apache License, Version 2.0"
+						url = "https://www.apache.org/licenses/LICENSE-2.0.txt"
 					}
 				}
 
 				developers {
 					developer {
-						name.set( "Karl Tauber" )
-						organization.set( "FormDev Software GmbH" )
-						organizationUrl.set( "https://www.formdev.com/" )
+						name = "Karl Tauber"
+						organization = "FormDev Software GmbH"
+						organizationUrl = "https://www.formdev.com/"
 					}
 				}
 
 				scm {
-					connection.set( "scm:git:git://github.com/JFormDesigner/FlatLaf.git" )
-					url.set( "https://github.com/JFormDesigner/FlatLaf" )
+					connection = "scm:git:git://github.com/JFormDesigner/FlatLaf.git"
+					url = "https://github.com/JFormDesigner/FlatLaf"
 				}
 
 				issueManagement {
-					system.set( "GitHub" )
-					url.set( "https://github.com/JFormDesigner/FlatLaf/issues" )
+					system = "GitHub"
+					url = "https://github.com/JFormDesigner/FlatLaf/issues"
 				}
 			}
 
@@ -86,24 +86,26 @@ publishing {
 		}
 	}
 
+/*
 	repositories {
 		maven {
-			name = "OSSRH"
+			name = "MavenCentral"
 
-			val releasesRepoUrl = "https://oss.sonatype.org/service/local/staging/deploy/maven2/"
-			val snapshotsRepoUrl = "https://oss.sonatype.org/content/repositories/snapshots/"
+			val releasesRepoUrl = "https://ossrh-staging-api.central.sonatype.com/service/local/staging/deploy/maven2/"
+			val snapshotsRepoUrl = "https://central.sonatype.com/repository/maven-snapshots/"
 			url = uri( if( rootProject.hasProperty( "release" ) ) releasesRepoUrl else snapshotsRepoUrl )
 
 			credentials {
 				// get from gradle.properties
-				val ossrhUsername: String? by project
-				val ossrhPassword: String? by project
+				val sonatypeUsername: String? by project
+				val sonatypePassword: String? by project
 
-				username = System.getenv( "OSSRH_USERNAME" ) ?: ossrhUsername
-				password = System.getenv( "OSSRH_PASSWORD" ) ?: ossrhPassword
+				username = System.getenv( "SONATYPE_USERNAME" ) ?: sonatypeUsername
+				password = System.getenv( "SONATYPE_PASSWORD" ) ?: sonatypePassword
 			}
 		}
 	}
+*/
 }
 
 signing {
@@ -124,7 +126,7 @@ tasks.withType<Sign>().configureEach {
 }
 
 // check whether parallel build is enabled
-tasks.withType<PublishToMavenRepository>().configureEach {
+tasks.withType<AbstractPublishToMaven>().configureEach {
 	doFirst {
 		if( System.getProperty( "org.gradle.parallel" ) == "true" )
 			throw RuntimeException( "Publishing does not work correctly with enabled parallel build. Disable parallel build with VM option '-Dorg.gradle.parallel=false'." )

buildSrc/src/main/kotlin/flatlaf-toolchain.gradle.kts

@@ -21,6 +21,6 @@ plugins {
 val toolchainJavaVersion = System.getProperty( "toolchain" )
 if( !toolchainJavaVersion.isNullOrEmpty() ) {
 	java.toolchain {
-		languageVersion.set( JavaLanguageVersion.of( toolchainJavaVersion ) )
+		languageVersion = JavaLanguageVersion.of( toolchainJavaVersion )
 	}
 }

flatlaf-core/.settings/org.eclipse.jdt.core.prefs

@@ -1,4 +1,7 @@
 eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8
+org.eclipse.jdt.core.compiler.compliance=1.8
+org.eclipse.jdt.core.compiler.source=1.8
 org.eclipse.jdt.core.formatter.align_assignment_statements_on_columns=false
 org.eclipse.jdt.core.formatter.align_fields_grouping_blank_lines=2147483647
 org.eclipse.jdt.core.formatter.align_type_members_on_columns=false

flatlaf-core/build.gradle.kts

@@ -27,8 +27,8 @@ plugins {
 val sigtest = configurations.create( "sigtest" )
 
 dependencies {
-	testImplementation( libs.bundles.junit )
-	testRuntimeOnly( libs.junit.engine )
+	testImplementation( libs.junit )
+	testRuntimeOnly( libs.junit.launcher )
 
 	// https://github.com/jtulach/netbeans-apitest
 	sigtest( libs.sigtest )
@@ -42,11 +42,11 @@ java {
 tasks {
 	compileJava {
 		// generate JNI headers
-		options.headerOutputDirectory.set( layout.buildDirectory.dir( "generated/jni-headers" ) )
+		options.headerOutputDirectory = layout.buildDirectory.dir( "generated/jni-headers" )
 	}
 
 	jar {
-		archiveBaseName.set( "flatlaf" )
+		archiveBaseName = "flatlaf"
 
 		doLast {
 			ReorderJarEntries.reorderJarEntries( outputs.files.singleFile );
@@ -54,11 +54,32 @@ tasks {
 	}
 
 	named<Jar>( "sourcesJar" ) {
-		archiveBaseName.set( "flatlaf" )
+		archiveBaseName = "flatlaf"
 	}
 
 	named<Jar>( "javadocJar" ) {
-		archiveBaseName.set( "flatlaf" )
+		archiveBaseName = "flatlaf"
+	}
+
+	register<Zip>( "jarNoNatives" ) {
+		group = "build"
+		dependsOn( "jar" )
+
+		archiveBaseName = "flatlaf"
+		archiveClassifier = "no-natives"
+		archiveExtension = "jar"
+		destinationDirectory = layout.buildDirectory.dir( "libs" )
+
+		from( zipTree( jar.get().archiveFile.get().asFile ) )
+		exclude( "com/formdev/flatlaf/natives/**" )
+	}
+
+	withType<AbstractPublishToMaven>().configureEach {
+		dependsOn( "jarNoNatives" )
+	}
+
+	withType<Sign>().configureEach {
+		dependsOn( "jarNoNatives" )
 	}
 
 	check {
@@ -127,9 +148,14 @@ flatlafPublish {
 
 	val natives = "src/main/resources/com/formdev/flatlaf/natives"
 	nativeArtifacts = listOf(
+		NativeArtifact( tasks.getByName( "jarNoNatives" ).outputs.files.asPath, "no-natives", "jar" ),
+
 		NativeArtifact( "${natives}/flatlaf-windows-x86.dll",       "windows-x86",    "dll" ),
 		NativeArtifact( "${natives}/flatlaf-windows-x86_64.dll",    "windows-x86_64", "dll" ),
 		NativeArtifact( "${natives}/flatlaf-windows-arm64.dll",     "windows-arm64",  "dll" ),
+		NativeArtifact( "${natives}/libflatlaf-macos-arm64.dylib",  "macos-arm64",    "dylib" ),
+		NativeArtifact( "${natives}/libflatlaf-macos-x86_64.dylib", "macos-x86_64",   "dylib" ),
 		NativeArtifact( "${natives}/libflatlaf-linux-x86_64.so",    "linux-x86_64",   "so" ),
+		NativeArtifact( "${natives}/libflatlaf-linux-arm64.so",     "linux-arm64",    "so" ),
 	)
 }

flatlaf-core/flatlaf-core-sigtest.txt

@@ -1,5 +1,5 @@
 #Signature file v4.1
-#Version 3.2.4
+#Version 3.6.2
 
 CLSS public abstract interface com.formdev.flatlaf.FlatClientProperties
 fld public final static java.lang.String BUTTON_TYPE = "JButton.buttonType"
@@ -12,17 +12,25 @@ fld public final static java.lang.String BUTTON_TYPE_TOOLBAR_BUTTON = "toolBarBu
 fld public final static java.lang.String COMPONENT_FOCUS_OWNER = "JComponent.focusOwner"
 fld public final static java.lang.String COMPONENT_ROUND_RECT = "JComponent.roundRect"
 fld public final static java.lang.String COMPONENT_TITLE_BAR_CAPTION = "JComponent.titleBarCaption"
+fld public final static java.lang.String FULL_WINDOW_CONTENT = "FlatLaf.fullWindowContent"
+fld public final static java.lang.String FULL_WINDOW_CONTENT_BUTTONS_BOUNDS = "FlatLaf.fullWindowContent.buttonsBounds"
+fld public final static java.lang.String FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER = "FlatLaf.fullWindowContent.buttonsPlaceholder"
 fld public final static java.lang.String GLASS_PANE_FULL_HEIGHT = "JRootPane.glassPaneFullHeight"
+fld public final static java.lang.String MACOS_WINDOW_BUTTONS_SPACING = "FlatLaf.macOS.windowButtonsSpacing"
+fld public final static java.lang.String MACOS_WINDOW_BUTTONS_SPACING_LARGE = "large"
+fld public final static java.lang.String MACOS_WINDOW_BUTTONS_SPACING_MEDIUM = "medium"
 fld public final static java.lang.String MENU_BAR_EMBEDDED = "JRootPane.menuBarEmbedded"
 fld public final static java.lang.String MINIMUM_HEIGHT = "JComponent.minimumHeight"
 fld public final static java.lang.String MINIMUM_WIDTH = "JComponent.minimumWidth"
 fld public final static java.lang.String OUTLINE = "JComponent.outline"
 fld public final static java.lang.String OUTLINE_ERROR = "error"
+fld public final static java.lang.String OUTLINE_SUCCESS = "success"
 fld public final static java.lang.String OUTLINE_WARNING = "warning"
 fld public final static java.lang.String PLACEHOLDER_TEXT = "JTextField.placeholderText"
 fld public final static java.lang.String POPUP_BORDER_CORNER_RADIUS = "Popup.borderCornerRadius"
 fld public final static java.lang.String POPUP_DROP_SHADOW_PAINTED = "Popup.dropShadowPainted"
 fld public final static java.lang.String POPUP_FORCE_HEAVY_WEIGHT = "Popup.forceHeavyWeight"
+fld public final static java.lang.String POPUP_ROUNDED_BORDER_WIDTH = "Popup.roundedBorderWidth"
 fld public final static java.lang.String PROGRESS_BAR_LARGE_HEIGHT = "JProgressBar.largeHeight"
 fld public final static java.lang.String PROGRESS_BAR_SQUARE = "JProgressBar.square"
 fld public final static java.lang.String SCROLL_BAR_SHOW_BUTTONS = "JScrollBar.showButtons"
@@ -33,6 +41,7 @@ fld public final static java.lang.String SELECT_ALL_ON_FOCUS_POLICY = "JTextFiel
 fld public final static java.lang.String SELECT_ALL_ON_FOCUS_POLICY_ALWAYS = "always"
 fld public final static java.lang.String SELECT_ALL_ON_FOCUS_POLICY_NEVER = "never"
 fld public final static java.lang.String SELECT_ALL_ON_FOCUS_POLICY_ONCE = "once"
+fld public final static java.lang.String SELECT_ALL_ON_MOUSE_CLICK = "JTextField.selectAllOnMouseClick"
 fld public final static java.lang.String SPLIT_PANE_EXPANDABLE_SIDE = "JSplitPane.expandableSide"
 fld public final static java.lang.String SPLIT_PANE_EXPANDABLE_SIDE_LEFT = "left"
 fld public final static java.lang.String SPLIT_PANE_EXPANDABLE_SIDE_RIGHT = "right"
@@ -67,6 +76,11 @@ fld public final static java.lang.String TABBED_PANE_TAB_CLOSE_TOOLTIPTEXT = "JT
 fld public final static java.lang.String TABBED_PANE_TAB_HEIGHT = "JTabbedPane.tabHeight"
 fld public final static java.lang.String TABBED_PANE_TAB_ICON_PLACEMENT = "JTabbedPane.tabIconPlacement"
 fld public final static java.lang.String TABBED_PANE_TAB_INSETS = "JTabbedPane.tabInsets"
+fld public final static java.lang.String TABBED_PANE_TAB_ROTATION = "JTabbedPane.tabRotation"
+fld public final static java.lang.String TABBED_PANE_TAB_ROTATION_AUTO = "auto"
+fld public final static java.lang.String TABBED_PANE_TAB_ROTATION_LEFT = "left"
+fld public final static java.lang.String TABBED_PANE_TAB_ROTATION_NONE = "none"
+fld public final static java.lang.String TABBED_PANE_TAB_ROTATION_RIGHT = "right"
 fld public final static java.lang.String TABBED_PANE_TAB_TYPE = "JTabbedPane.tabType"
 fld public final static java.lang.String TABBED_PANE_TAB_TYPE_CARD = "card"
 fld public final static java.lang.String TABBED_PANE_TAB_TYPE_UNDERLINED = "underlined"
@@ -88,12 +102,14 @@ fld public final static java.lang.String TEXT_FIELD_TRAILING_COMPONENT = "JTextF
 fld public final static java.lang.String TEXT_FIELD_TRAILING_ICON = "JTextField.trailingIcon"
 fld public final static java.lang.String TITLE_BAR_BACKGROUND = "JRootPane.titleBarBackground"
 fld public final static java.lang.String TITLE_BAR_FOREGROUND = "JRootPane.titleBarForeground"
+fld public final static java.lang.String TITLE_BAR_HEIGHT = "JRootPane.titleBarHeight"
 fld public final static java.lang.String TITLE_BAR_SHOW_CLOSE = "JRootPane.titleBarShowClose"
 fld public final static java.lang.String TITLE_BAR_SHOW_ICON = "JRootPane.titleBarShowIcon"
 fld public final static java.lang.String TITLE_BAR_SHOW_ICONIFFY = "JRootPane.titleBarShowIconify"
 fld public final static java.lang.String TITLE_BAR_SHOW_MAXIMIZE = "JRootPane.titleBarShowMaximize"
 fld public final static java.lang.String TITLE_BAR_SHOW_TITLE = "JRootPane.titleBarShowTitle"
 fld public final static java.lang.String TREE_PAINT_SELECTION = "JTree.paintSelection"
+fld public final static java.lang.String TREE_WIDE_CELL_RENDERER = "JTree.wideCellRenderer"
 fld public final static java.lang.String TREE_WIDE_SELECTION = "JTree.wideSelection"
 fld public final static java.lang.String USE_WINDOW_DECORATIONS = "JRootPane.useWindowDecorations"
 fld public final static java.lang.String WINDOW_STYLE = "Window.style"
@@ -207,10 +223,14 @@ meth public static java.lang.String getPreferredFontFamily()
 meth public static java.lang.String getPreferredLightFontFamily()
 meth public static java.lang.String getPreferredMonospacedFontFamily()
 meth public static java.lang.String getPreferredSemiboldFontFamily()
+meth public static java.lang.String getUIKeyLightOrDarkPrefix(boolean)
 meth public static java.util.Map<java.lang.String,java.lang.Class<?>> getStyleableInfos(javax.swing.JComponent)
 meth public static java.util.Map<java.lang.String,java.lang.String> getGlobalExtraDefaults()
+meth public static java.util.Set<java.lang.String> getUIKeyPlatformPrefixes()
+meth public static java.util.Set<java.lang.String> getUIKeySpecialPrefixes()
 meth public static java.util.function.Function<java.lang.String,java.awt.Color> getSystemColorGetter()
 meth public static javax.swing.UIDefaults$ActiveValue createActiveFontValue(float)
+meth public static void disableWindowsD3Donscreen()
 meth public static void hideMnemonics()
 meth public static void initIconColors(javax.swing.UIDefaults,boolean)
 meth public static void installLafInfo(java.lang.String,java.lang.Class<? extends javax.swing.LookAndFeel>)
@@ -241,7 +261,7 @@ meth public void setExtraDefaults(java.util.Map<java.lang.String,java.lang.Strin
 meth public void uninitialize()
 meth public void unregisterUIDefaultsGetter(java.util.function.Function<java.lang.Object,java.lang.Object>)
 supr javax.swing.plaf.basic.BasicLookAndFeel
-hfds DESKTOPFONTHINTS,aquaLoaded,customDefaultsSources,desktopPropertyListener,desktopPropertyName,desktopPropertyName2,extraDefaults,getUIMethod,getUIMethodInitialized,globalExtraDefaults,mnemonicHandler,oldPopupFactory,postInitialization,preferredFontFamily,preferredLightFontFamily,preferredMonospacedFontFamily,preferredSemiboldFontFamily,subMenuUsabilityHelperInstalled,systemColorGetter,uiDefaultsGetters,updateUIPending
+hfds DESKTOPFONTHINTS,aquaLoaded,customDefaultsSources,desktopPropertyListener,desktopPropertyName,desktopPropertyName2,extraDefaults,globalExtraDefaults,linuxPopupMenuCanceler,mnemonicHandler,oldPopupFactory,postInitialization,preferredFontFamily,preferredLightFontFamily,preferredMonospacedFontFamily,preferredSemiboldFontFamily,subMenuUsabilityHelperInstalled,systemColorGetter,uiDefaultsGetters,uiKeyPlatformPrefixes,uiKeySpecialPrefixes,updateUIPending
 hcls ActiveFont,FlatUIDefaults,ImageIconUIResource
 
 CLSS public abstract interface static com.formdev.flatlaf.FlatLaf$DisabledIconProvider
@@ -277,12 +297,16 @@ CLSS public abstract interface com.formdev.flatlaf.FlatSystemProperties
 fld public final static java.lang.String ANIMATION = "flatlaf.animation"
 fld public final static java.lang.String MENUBAR_EMBEDDED = "flatlaf.menuBarEmbedded"
 fld public final static java.lang.String NATIVE_LIBRARY_PATH = "flatlaf.nativeLibraryPath"
+fld public final static java.lang.String REUSE_VISIBLE_POPUP_WINDOW = "flatlaf.reuseVisiblePopupWindow"
 fld public final static java.lang.String UI_SCALE = "flatlaf.uiScale"
 fld public final static java.lang.String UI_SCALE_ALLOW_SCALE_DOWN = "flatlaf.uiScale.allowScaleDown"
 fld public final static java.lang.String UI_SCALE_ENABLED = "flatlaf.uiScale.enabled"
 fld public final static java.lang.String UPDATE_UI_ON_SYSTEM_FONT_CHANGE = "flatlaf.updateUIOnSystemFontChange"
 fld public final static java.lang.String USE_JETBRAINS_CUSTOM_DECORATIONS = "flatlaf.useJetBrainsCustomDecorations"
+ anno 0 java.lang.Deprecated()
 fld public final static java.lang.String USE_NATIVE_LIBRARY = "flatlaf.useNativeLibrary"
+fld public final static java.lang.String USE_ROUNDED_POPUP_BORDER = "flatlaf.useRoundedPopupBorder"
+fld public final static java.lang.String USE_SUB_MENU_SAFE_TRIANGLE = "flatlaf.useSubMenuSafeTriangle"
 fld public final static java.lang.String USE_TEXT_Y_CORRECTION = "flatlaf.useTextYCorrection"
 fld public final static java.lang.String USE_UBUNTU_FONT = "flatlaf.useUbuntuFont"
 fld public final static java.lang.String USE_WINDOW_DECORATIONS = "flatlaf.useWindowDecorations"
@@ -301,7 +325,7 @@ meth public static boolean setup(java.io.InputStream)
 meth public static com.formdev.flatlaf.FlatLaf createLaf(com.formdev.flatlaf.IntelliJTheme)
 meth public static com.formdev.flatlaf.FlatLaf createLaf(java.io.InputStream) throws java.io.IOException
 supr java.lang.Object
-hfds checkboxDuplicateColors,checkboxKeyMapping,colors,icons,isMaterialUILite,namedColors,ui,uiKeyCopying,uiKeyDoNotOverride,uiKeyExcludes,uiKeyInverseMapping,uiKeyMapping
+hfds checkboxDuplicateColors,checkboxKeyMapping,jsonColors,jsonIcons,jsonUI,namedColors,uiKeyCopying,uiKeyDoNotOverride,uiKeyExcludesContains,uiKeyExcludesStartsWith,uiKeyInverseMapping,uiKeyMapping
 
 CLSS public static com.formdev.flatlaf.IntelliJTheme$ThemeLaf
  outer com.formdev.flatlaf.IntelliJTheme
@@ -396,6 +420,7 @@ innr public static Fade
 innr public static HSLChange
 innr public static HSLIncreaseDecrease
 innr public static Mix
+innr public static Mix2
 meth public !varargs static java.awt.Color applyFunctions(java.awt.Color,com.formdev.flatlaf.util.ColorFunctions$ColorFunction[])
 meth public static float clamp(float)
 meth public static float luma(java.awt.Color)
@@ -457,6 +482,16 @@ meth public java.lang.String toString()
 meth public void apply(float[])
 supr java.lang.Object
 
+CLSS public static com.formdev.flatlaf.util.ColorFunctions$Mix2
+ outer com.formdev.flatlaf.util.ColorFunctions
+cons public init(java.awt.Color,float)
+fld public final float weight
+fld public final java.awt.Color color1
+intf com.formdev.flatlaf.util.ColorFunctions$ColorFunction
+meth public java.lang.String toString()
+meth public void apply(float[])
+supr java.lang.Object
+
 CLSS public com.formdev.flatlaf.util.CubicBezierEasing
 cons public init(float,float,float,float)
 fld public final static com.formdev.flatlaf.util.CubicBezierEasing EASE
@@ -616,16 +651,33 @@ hfds alpha,hsl,rgb
 
 CLSS public com.formdev.flatlaf.util.HiDPIUtils
 cons public init()
+innr public abstract interface static DirtyRegionCallback
 innr public abstract interface static Painter
+innr public static HiDPIRepaintManager
 meth public static float computeTextYCorrection(java.awt.Graphics2D)
 meth public static java.awt.Graphics2D createGraphicsTextYCorrection(java.awt.Graphics2D)
+meth public static void addDirtyRegion(javax.swing.JComponent,int,int,int,int,com.formdev.flatlaf.util.HiDPIUtils$DirtyRegionCallback)
 meth public static void drawStringUnderlineCharAtWithYCorrection(javax.swing.JComponent,java.awt.Graphics2D,java.lang.String,int,int,int)
 meth public static void drawStringWithYCorrection(javax.swing.JComponent,java.awt.Graphics2D,java.lang.String,int,int)
+meth public static void installHiDPIRepaintManager()
 meth public static void paintAtScale1x(java.awt.Graphics2D,int,int,int,int,com.formdev.flatlaf.util.HiDPIUtils$Painter)
 meth public static void paintAtScale1x(java.awt.Graphics2D,javax.swing.JComponent,com.formdev.flatlaf.util.HiDPIUtils$Painter)
+meth public static void repaint(java.awt.Component)
+meth public static void repaint(java.awt.Component,int,int,int,int)
+meth public static void repaint(java.awt.Component,java.awt.Rectangle)
 supr java.lang.Object
 hfds CORRECTION_INTER,CORRECTION_OPEN_SANS,CORRECTION_SEGOE_UI,CORRECTION_TAHOMA,SCALE_FACTORS,useDebugScaleFactor,useTextYCorrection
 
+CLSS public abstract interface static com.formdev.flatlaf.util.HiDPIUtils$DirtyRegionCallback
+ outer com.formdev.flatlaf.util.HiDPIUtils
+meth public abstract void addDirtyRegion(javax.swing.JComponent,int,int,int,int)
+
+CLSS public static com.formdev.flatlaf.util.HiDPIUtils$HiDPIRepaintManager
+ outer com.formdev.flatlaf.util.HiDPIUtils
+cons public init()
+meth public void addDirtyRegion(javax.swing.JComponent,int,int,int,int)
+supr javax.swing.RepaintManager
+
 CLSS public abstract interface static com.formdev.flatlaf.util.HiDPIUtils$Painter
  outer com.formdev.flatlaf.util.HiDPIUtils
 meth public abstract void paint(java.awt.Graphics2D,int,int,int,int,double)
@@ -721,6 +773,7 @@ supr java.lang.Object
 CLSS public com.formdev.flatlaf.util.SystemInfo
 cons public init()
 fld public final static boolean isAARCH64
+fld public final static boolean isGNOME
 fld public final static boolean isJava_11_orLater
 fld public final static boolean isJava_12_orLater
 fld public final static boolean isJava_15_orLater
@@ -737,6 +790,7 @@ fld public final static boolean isMacOS_10_11_ElCapitan_orLater
 fld public final static boolean isMacOS_10_14_Mojave_orLater
 fld public final static boolean isMacOS_10_15_Catalina_orLater
 fld public final static boolean isProjector
+fld public final static boolean isUnknownOS
 fld public final static boolean isWebswing
 fld public final static boolean isWinPE
 fld public final static boolean isWindows
@@ -1124,6 +1178,31 @@ meth public void provideErrorFeedback(java.awt.Component)
 meth public void uninitialize()
 supr java.lang.Object
 
+CLSS public javax.swing.RepaintManager
+cons public init()
+meth public boolean isCompletelyDirty(javax.swing.JComponent)
+meth public boolean isDoubleBufferingEnabled()
+meth public java.awt.Dimension getDoubleBufferMaximumSize()
+meth public java.awt.Image getOffscreenBuffer(java.awt.Component,int,int)
+meth public java.awt.Image getVolatileOffscreenBuffer(java.awt.Component,int,int)
+meth public java.awt.Rectangle getDirtyRegion(javax.swing.JComponent)
+meth public java.lang.String toString()
+meth public static javax.swing.RepaintManager currentManager(java.awt.Component)
+meth public static javax.swing.RepaintManager currentManager(javax.swing.JComponent)
+meth public static void setCurrentManager(javax.swing.RepaintManager)
+meth public void addDirtyRegion(java.applet.Applet,int,int,int,int)
+meth public void addDirtyRegion(java.awt.Window,int,int,int,int)
+meth public void addDirtyRegion(javax.swing.JComponent,int,int,int,int)
+meth public void addInvalidComponent(javax.swing.JComponent)
+meth public void markCompletelyClean(javax.swing.JComponent)
+meth public void markCompletelyDirty(javax.swing.JComponent)
+meth public void paintDirtyRegions()
+meth public void removeInvalidComponent(javax.swing.JComponent)
+meth public void setDoubleBufferMaximumSize(java.awt.Dimension)
+meth public void setDoubleBufferingEnabled(boolean)
+meth public void validateInvalidComponents()
+supr java.lang.Object
+
 CLSS public abstract javax.swing.border.AbstractBorder
 cons public init()
 intf java.io.Serializable

flatlaf-core/src/main/java/com/formdev/flatlaf/FlatClientProperties.java

@@ -21,6 +21,8 @@ import java.awt.IllegalComponentStateException;
 import java.awt.Window;
 import java.util.Objects;
 import javax.swing.JComponent;
+import javax.swing.JFormattedTextField;
+import javax.swing.JSpinner;
 import javax.swing.SwingConstants;
 
 /**
@@ -33,7 +35,7 @@ public interface FlatClientProperties
 	//---- JButton ------------------------------------------------------------
 
 	/**
-	 * Specifies type of a button.
+	 * Specifies type of button.
 	 * <p>
 	 * <strong>Components</strong> {@link javax.swing.JButton} and {@link javax.swing.JToggleButton}<br>
 	 * <strong>Value type</strong> {@link java.lang.String}<br>
@@ -102,6 +104,17 @@ public interface FlatClientProperties
 	 */
 	String BUTTON_TYPE_BORDERLESS = "borderless";
 
+	/**
+	 * Specifies whether the button preferred size will be made square (quadratically).
+	 * <p>
+	 * <strong>Components</strong> {@link javax.swing.JButton} and {@link javax.swing.JToggleButton}<br>
+	 * <strong>Value type</strong> {@link java.lang.Boolean}
+	 */
+	String SQUARE_SIZE = "JButton.squareSize";
+
+
+	//---- JCheckBox ----------------------------------------------------------
+
 	/**
 	 * Specifies selected state of a checkbox.
 	 * <p>
@@ -118,14 +131,6 @@ public interface FlatClientProperties
 	 */
 	String SELECTED_STATE_INDETERMINATE = "indeterminate";
 
-	/**
-	 * Specifies whether the button preferred size will be made square (quadratically).
-	 * <p>
-	 * <strong>Components</strong> {@link javax.swing.JButton} and {@link javax.swing.JToggleButton}<br>
-	 * <strong>Value type</strong> {@link java.lang.Boolean}
-	 */
-	String SQUARE_SIZE = "JButton.squareSize";
-
 
 	//---- JComponent ---------------------------------------------------------
 
@@ -217,6 +222,7 @@ public interface FlatClientProperties
 	 * <strong>Allowed Values</strong>
 	 *     {@link #OUTLINE_ERROR},
 	 *     {@link #OUTLINE_WARNING},
+	 *     {@link #OUTLINE_SUCCESS},
 	 *     any color (type {@link java.awt.Color}) or
 	 *     an array of two colors (type {@link java.awt.Color}[2]) where the first color
 	 *     is for focused state and the second for unfocused state
@@ -237,6 +243,14 @@ public interface FlatClientProperties
 	 */
 	String OUTLINE_WARNING = "warning";
 
+	/**
+	 * Paint the component border in another color (usually greenish) to indicate a success.
+	 *
+	 * @see #OUTLINE
+	 * @since 3.6
+	 */
+	String OUTLINE_SUCCESS = "success";
+
 	/**
 	 * Specifies a callback that is invoked to check whether a component is permanent focus owner.
 	 * Used to paint focus indicators.
@@ -257,19 +271,116 @@ public interface FlatClientProperties
 	String COMPONENT_FOCUS_OWNER = "JComponent.focusOwner";
 
 	/**
-	 * Specifies whether a component in an embedded menu bar should behave as caption
+	 * Specifies whether a component shown in a window title bar area should behave as caption
 	 * (left-click allows moving window, right-click shows window system menu).
-	 * The component does not receive mouse pressed/released/clicked/dragged events,
+	 * The caption component does not receive mouse pressed/released/clicked/dragged events,
 	 * but it gets mouse entered/exited/moved events.
 	 * <p>
+	 * Since 3.4, this client property also supports using a function that can check
+	 * whether a given location in the component should behave as caption.
+	 * Useful for components that do not use mouse input on whole component bounds.
+	 *
+	 * <pre>{@code
+	 * myComponent.putClientProperty( "JComponent.titleBarCaption",
+	 *     (Function<Point, Boolean>) pt -> {
+	 *         // parameter pt contains mouse location (in myComponent coordinates)
+	 *         // return true if the component is not interested in mouse input at the given location
+	 *         // return false if the component wants process mouse input at the given location
+	 *         // return null if the component children should be checked
+	 *         return ...; // check here
+	 *     } );
+	 * }</pre>
+	 * <b>Warning</b>:
+	 * <ul>
+	 *   <li>This function is invoked often when mouse is moved over window title bar area
+	 *       and should therefore return quickly.
+	 *   <li>This function is invoked on 'AWT-Windows' thread (not 'AWT-EventQueue' thread)
+	 *       while processing Windows messages.
+	 *       It <b>must not</b> change any component property or layout because this could cause a dead lock.
+	 * </ul>
+	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JComponent}<br>
-	 * <strong>Value type</strong> {@link java.lang.Boolean}
+	 * <strong>Value type</strong> {@link java.lang.Boolean} or {@link java.util.function.Function}&lt;Point, Boolean&gt;
 	 *
 	 * @since 2.5
 	 */
 	String COMPONENT_TITLE_BAR_CAPTION = "JComponent.titleBarCaption";
 
 
+	//---- Panel --------------------------------------------------------------
+
+	/**
+	 * Marks the panel as placeholder for the iconfify/maximize/close buttons
+	 * in fullWindowContent mode. See {@link #FULL_WINDOW_CONTENT}.
+	 * <p>
+	 * If fullWindowContent mode is enabled, the preferred size of the panel is equal
+	 * to the size of the iconfify/maximize/close buttons. Otherwise is is {@code 0,0}.
+	 * <p>
+	 * You're responsible to layout that panel at the top-left or top-right corner,
+	 * depending on platform, where the iconfify/maximize/close buttons are located.
+	 * <p>
+	 * Syntax of the value string is: {@code "win|mac [horizontal|vertical] [zeroInFullScreen] [leftToRight|rightToLeft]"}.
+	 * <p>
+	 * The string must start with {@code "win"} (for Windows or Linux) or
+	 * with {@code "mac"} (for macOS) and specifies the platform where the placeholder
+	 * should be used. On macOS, you need the placeholder in the top-left corner,
+	 * but on Windows/Linux you need it in the top-right corner. So if your application supports
+	 * fullWindowContent mode on both platforms, you can add two placeholders to your layout
+	 * and FlatLaf automatically uses only one of them. The other gets size {@code 0,0}.
+	 * <p>
+	 * Optionally, you can append following options to the value string (separated by space characters):
+	 * <ul>
+	 *   <li>{@code "horizontal"} - preferred height is zero
+	 *   <li>{@code "vertical"} - preferred width is zero
+	 *   <li>{@code "zeroInFullScreen"} - in full-screen mode on macOS, preferred size is {@code 0,0}
+	 *   <li>{@code "leftToRight"} - in right-to-left component orientation, preferred size is {@code 0,0}
+	 *   <li>{@code "rightToLeft"} - in left-to-right component orientation, preferred size is {@code 0,0}
+	 * </ul>
+	 *
+	 * Example for adding placeholder to top-left corner on macOS:
+	 * <pre>{@code
+	 * JPanel placeholder = new JPanel();
+	 * placeholder.putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER, "mac" );
+     *
+     * JToolBar toolBar = new JToolBar();
+     * // add tool bar items
+     *
+	 * JPanel toolBarPanel = new JPanel( new BorderLayout() );
+	 * toolBarPanel.add( placeholder, BorderLayout.WEST );
+	 * toolBarPanel.add( toolBar, BorderLayout.CENTER );
+	 *
+	 * frame.getContentPane().add( toolBarPanel, BorderLayout.NORTH );
+	 * }</pre>
+	 *
+	 * Or add placeholder as first item to the tool bar:
+	 * <pre>{@code
+	 * JPanel placeholder = new JPanel();
+	 * placeholder.putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER, "mac" );
+	 *
+	 * JToolBar toolBar = new JToolBar();
+	 * toolBar.add( placeholder );
+	 * // add tool bar items
+	 *
+	 * frame.getContentPane().add( toolBar, BorderLayout.NORTH );
+	 * }</pre>
+	 *
+	 * If a tabbed pane is located at the top, you can add the placeholder
+	 * as leading component to that tabbed pane:
+	 * <pre>{@code
+	 * JPanel placeholder = new JPanel();
+	 * placeholder.putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER, "mac" );
+	 *
+	 * tabbedPane.putClientProperty( FlatClientProperties.TABBED_PANE_LEADING_COMPONENT, placeholder );
+	 * }</pre>
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JPanel}<br>
+	 * <strong>Value type</strong> {@link java.lang.String}
+	 *
+	 * @since 3.4
+	 */
+	String FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER = "FlatLaf.fullWindowContent.buttonsPlaceholder";
+
+
 	//---- Popup --------------------------------------------------------------
 
 	/**
@@ -278,12 +389,13 @@ public interface FlatClientProperties
 	 * <p>
 	 * Note that this is not available on all platforms since it requires special support.
 	 * Supported platforms:
-	 * <p>
-	 * <strong>Windows 11</strong> (x86 or x86_64): Only two corner radiuses are supported
+	 * <ul>
+	 * <li><strong>Windows 11</strong>: Only two corner radiuses are supported
 	 *     by the OS: {@code DWMWCP_ROUND} is 8px and {@code DWMWCP_ROUNDSMALL} is 4px.
 	 *     If this value is {@code 1 - 4}, then {@code DWMWCP_ROUNDSMALL} is used.
 	 *     If it is {@code >= 5}, then {@code DWMWCP_ROUND} is used.
-	 * <p>
+	 * <li><strong>macOS</strong> (10.14 and later): Any corner radius is supported.
+	 * </ul>
 	 * <strong>Component</strong> {@link javax.swing.JComponent}<br>
 	 * <strong>Value type</strong> {@link java.lang.Integer}<br>
 	 *
@@ -291,6 +403,24 @@ public interface FlatClientProperties
 	 */
 	String POPUP_BORDER_CORNER_RADIUS = "Popup.borderCornerRadius";
 
+	/**
+	 * Specifies the popup rounded border width if the component is shown in a popup
+	 * or if the component is the owner of another component that is shown in a popup.
+	 * <p>
+	 * Only used if popup uses rounded border.
+	 * <p>
+	 * Note that this is not available on all platforms since it requires special support.
+	 * Supported platforms:
+	 * <ul>
+	 * <li><strong>macOS</strong> (10.14 and later)
+	 * </ul>
+	 * <strong>Component</strong> {@link javax.swing.JComponent}<br>
+	 * <strong>Value type</strong> {@link java.lang.Integer} or {@link java.lang.Float}<br>
+	 *
+	 * @since 3.3
+	 */
+	String POPUP_ROUNDED_BORDER_WIDTH = "Popup.roundedBorderWidth";
+
 	/**
 	 * Specifies whether a drop shadow is painted if the component is shown in a popup
 	 * or if the component is the owner of another component that is shown in a popup.
@@ -342,7 +472,7 @@ public interface FlatClientProperties
 	 * {@link FlatSystemProperties#USE_WINDOW_DECORATIONS}, but higher priority
 	 * than UI default {@code TitlePane.useWindowDecorations}.
 	 * <p>
-	 * (requires Window 10)
+	 * (requires Windows 10/11)
 	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
 	 * <strong>Value type</strong> {@link java.lang.Boolean}
@@ -362,13 +492,55 @@ public interface FlatClientProperties
 	 * {@link FlatSystemProperties#MENUBAR_EMBEDDED}, but higher priority
 	 * than UI default {@code TitlePane.menuBarEmbedded}.
 	 * <p>
-	 * (requires Window 10)
+	 * (requires Windows 10/11)
 	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
 	 * <strong>Value type</strong> {@link java.lang.Boolean}
 	 */
 	String MENU_BAR_EMBEDDED = "JRootPane.menuBarEmbedded";
 
+	/**
+	 * Specifies whether the content pane (and the glass pane) should be extended
+	 * into the window title bar area
+	 * (requires enabled window decorations). Default is {@code false}.
+	 * <p>
+	 * On macOS, use client property {@code apple.awt.fullWindowContent}
+	 * (see <a href="https://www.formdev.com/flatlaf/macos/#full_window_content">macOS Full window content</a>).
+	 * <p>
+	 * Setting this enables/disables full window content
+	 * for the {@code JFrame} or {@code JDialog} that contains the root pane.
+	 * <p>
+	 * If {@code true}, the content pane (and the glass pane) is extended into
+	 * the title bar area. The window icon and title are hidden.
+	 * Only the iconfify/maximize/close buttons stay visible in the upper right corner
+	 * (and overlap the content pane).
+	 * <p>
+	 * The user can left-click-and-drag on the title bar area to move the window,
+	 * except when clicking on a component that processes mouse events (e.g. buttons or menus).
+	 * <p>
+	 * (requires Windows 10/11)
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
+	 * <strong>Value type</strong> {@link java.lang.Boolean}
+	 *
+	 * @since 3.4
+	 */
+	String FULL_WINDOW_CONTENT = "FlatLaf.fullWindowContent";
+
+	/**
+	 * Contains the current bounds of the iconfify/maximize/close buttons
+	 * (in root pane coordinates) if fullWindowContent mode is enabled.
+	 * Otherwise its value is {@code null}.
+	 * <p>
+	 * <b>Note</b>: Do not set this client property. It is set by FlatLaf.
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
+	 * <strong>Value type</strong> {@link java.awt.Rectangle}
+	 *
+	 * @since 3.4
+	 */
+	String FULL_WINDOW_CONTENT_BUTTONS_BOUNDS = "FlatLaf.fullWindowContent.buttonsBounds";
+
 	/**
 	 * Specifies whether the window icon should be shown in the window title bar
 	 * (requires enabled window decorations). Default is UI property {@code TitlePane.showIcon}.
@@ -378,7 +550,7 @@ public interface FlatClientProperties
 	 * <p>
 	 * This client property has higher priority than UI default {@code TitlePane.showIcon}.
 	 * <p>
-	 * (requires Window 10)
+	 * (requires Windows 10/11)
 	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
 	 * <strong>Value type</strong> {@link java.lang.Boolean}
@@ -394,6 +566,8 @@ public interface FlatClientProperties
 	 * Setting this shows/hides the windows title
 	 * for the {@code JFrame} or {@code JDialog} that contains the root pane.
 	 * <p>
+	 * (requires Windows 10/11)
+	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
 	 * <strong>Value type</strong> {@link java.lang.Boolean}
 	 *
@@ -402,12 +576,14 @@ public interface FlatClientProperties
 	String TITLE_BAR_SHOW_TITLE = "JRootPane.titleBarShowTitle";
 
 	/**
-	 * Specifies whether the "iconfify" button should be shown in the window title bar
+	 * Specifies whether the "iconify" button should be shown in the window title bar
 	 * (requires enabled window decorations). Default is {@code true}.
 	 * <p>
-	 * Setting this shows/hides the "iconfify" button
+	 * Setting this shows/hides the "iconify" button
 	 * for the {@code JFrame} that contains the root pane.
 	 * <p>
+	 * (requires Windows 10/11)
+	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
 	 * <strong>Value type</strong> {@link java.lang.Boolean}
 	 *
@@ -422,6 +598,8 @@ public interface FlatClientProperties
 	 * Setting this shows/hides the "maximize/restore" button
 	 * for the {@code JFrame} that contains the root pane.
 	 * <p>
+	 * (requires Windows 10/11)
+	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
 	 * <strong>Value type</strong> {@link java.lang.Boolean}
 	 *
@@ -436,6 +614,8 @@ public interface FlatClientProperties
 	 * Setting this shows/hides the "close" button
 	 * for the {@code JFrame} or {@code JDialog} that contains the root pane.
 	 * <p>
+	 * (requires Windows 10/11)
+	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
 	 * <strong>Value type</strong> {@link java.lang.Boolean}
 	 *
@@ -446,7 +626,7 @@ public interface FlatClientProperties
 	/**
 	 * Background color of window title bar (requires enabled window decorations).
 	 * <p>
-	 * (requires Window 10)
+	 * (requires Windows 10/11)
 	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
 	 * <strong>Value type</strong> {@link java.awt.Color}
@@ -458,7 +638,7 @@ public interface FlatClientProperties
 	/**
 	 * Foreground color of window title bar (requires enabled window decorations).
 	 * <p>
-	 * (requires Window 10)
+	 * (requires Windows 10/11)
 	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
 	 * <strong>Value type</strong> {@link java.awt.Color}
@@ -467,10 +647,24 @@ public interface FlatClientProperties
 	 */
 	String TITLE_BAR_FOREGROUND = "JRootPane.titleBarForeground";
 
+	/**
+	 * Specifies the preferred height of title bar (requires enabled window decorations).
+	 * <p>
+	 * (requires Windows 10/11)
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
+	 * <strong>Value type</strong> {@link java.lang.Integer}
+	 *
+	 * @since 3.5.2
+	 */
+	String TITLE_BAR_HEIGHT = "JRootPane.titleBarHeight";
+
 	/**
 	 * Specifies whether the glass pane should have full height and overlap the title bar,
 	 * if FlatLaf window decorations are enabled. Default is {@code false}.
 	 * <p>
+	 * (requires Windows 10/11)
+	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
 	 * <strong>Value type</strong> {@link java.lang.Boolean}
 	 *
@@ -487,7 +681,7 @@ public interface FlatClientProperties
 	 * On macOS, Java supports this out of the box.
 	 * <p>
 	 * Note that this client property must be set before the window becomes displayable.
-	 * Otherwise an {@link IllegalComponentStateException} is thrown.
+	 * Otherwise, an {@link IllegalComponentStateException} is thrown.
 	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
 	 * <strong>Value type</strong> {@link java.lang.String}<br>
@@ -828,7 +1022,7 @@ public interface FlatClientProperties
 	 * <strong>Component</strong> {@link javax.swing.JTabbedPane}<br>
 	 * <strong>Value type</strong> {@link java.lang.Integer} or {@link java.lang.String}<br>
 	 * <strong>Allowed Values</strong>
-	 *     {@link SwingConstants#LEADING} (default)
+	 *     {@link SwingConstants#LEADING} (default),
 	 *     {@link SwingConstants#TRAILING},
 	 *     {@link SwingConstants#CENTER},
 	 *     {@link #TABBED_PANE_ALIGN_LEADING} (default),
@@ -932,6 +1126,59 @@ public interface FlatClientProperties
 	 */
 	String TABBED_PANE_TAB_ICON_PLACEMENT = "JTabbedPane.tabIconPlacement";
 
+	/**
+	 * Specifies the rotation of the tabs (title, icon, etc.).
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JTabbedPane}<br>
+	 * <strong>Value type</strong> {@link java.lang.Integer} or {@link java.lang.String}<br>
+	 * <strong>Allowed Values</strong>
+	 *     {@link SwingConstants#LEFT},
+	 *     {@link SwingConstants#RIGHT},
+	 *     {@link #TABBED_PANE_TAB_ROTATION_NONE} (default),
+	 *     {@link #TABBED_PANE_TAB_ROTATION_AUTO},
+	 *     {@link #TABBED_PANE_TAB_ROTATION_LEFT} or
+	 *     {@link #TABBED_PANE_TAB_ROTATION_RIGHT}
+	 *
+	 * @since 3.3
+	 */
+	String TABBED_PANE_TAB_ROTATION = "JTabbedPane.tabRotation";
+
+	/**
+	 * Tabs are not rotated.
+	 *
+	 * @see #TABBED_PANE_TAB_ROTATION
+	 * @since 3.3
+	 */
+	String TABBED_PANE_TAB_ROTATION_NONE = "none";
+
+	/**
+	 * Tabs are rotated depending on tab placement.
+	 * <p>
+	 * For top and bottom tab placement, the tabs are not rotated.<br>
+	 * For left tab placement, the tabs are rotated counter-clockwise.<br>
+	 * For right tab placement, the tabs are rotated clockwise.
+	 *
+	 * @see #TABBED_PANE_TAB_ROTATION
+	 * @since 3.3
+	 */
+	String TABBED_PANE_TAB_ROTATION_AUTO = "auto";
+
+	/**
+	 * Tabs are rotated counter-clockwise.
+	 *
+	 * @see #TABBED_PANE_TAB_ROTATION
+	 * @since 3.3
+	 */
+	String TABBED_PANE_TAB_ROTATION_LEFT = "left";
+
+	/**
+	 * Tabs are rotated clockwise.
+	 *
+	 * @see #TABBED_PANE_TAB_ROTATION
+	 * @since 3.3
+	 */
+	String TABBED_PANE_TAB_ROTATION_RIGHT = "right";
+
 	/**
 	 * Specifies a component that will be placed at the leading edge of the tabs area.
 	 * <p>
@@ -964,12 +1211,15 @@ public interface FlatClientProperties
 	/**
 	 * Specifies whether all text is selected when the text component gains focus.
 	 * <p>
-	 * <strong>Component</strong> {@link javax.swing.JTextField} (and subclasses)<br>
+	 * <strong>Components</strong> {@link javax.swing.text.JTextComponent} (and subclasses),
+	 * {@link javax.swing.JComboBox} (since 3.6) and {@link javax.swing.JSpinner} (since 3.6)<br>
 	 * <strong>Value type</strong> {@link java.lang.String}<br>
 	 * <strong>Allowed Values</strong>
 	 *     {@link #SELECT_ALL_ON_FOCUS_POLICY_NEVER},
 	 *     {@link #SELECT_ALL_ON_FOCUS_POLICY_ONCE} (default) or
 	 *     {@link #SELECT_ALL_ON_FOCUS_POLICY_ALWAYS}
+	 *
+	 * @see #SELECT_ALL_ON_MOUSE_CLICK
 	 */
 	String SELECT_ALL_ON_FOCUS_POLICY = "JTextField.selectAllOnFocusPolicy";
 
@@ -984,6 +1234,12 @@ public interface FlatClientProperties
 	 * Select all text when the text component gains focus for the first time
 	 * and selection was not modified (is at end of text).
 	 * This is the default.
+	 * <p>
+	 * <b>Limitations:</b>
+	 * For {@link JFormattedTextField} and {@link JSpinner} this behaves
+	 * as {@link #SELECT_ALL_ON_FOCUS_POLICY_ALWAYS}.
+     * This is because of special behavior of {@link JFormattedTextField}
+     * that did not allow implementation of {@code "once"}.
 	 *
 	 * @see #SELECT_ALL_ON_FOCUS_POLICY
 	 */
@@ -996,6 +1252,19 @@ public interface FlatClientProperties
 	 */
 	String SELECT_ALL_ON_FOCUS_POLICY_ALWAYS = "always";
 
+	/**
+	 * Specifies whether all text is selected when when clicking with the mouse
+	 * into the text field (and if "select all on focus" policy is enabled).
+	 * <p>
+	 * <strong>Components</strong> {@link javax.swing.text.JTextComponent} (and subclasses),
+	 * {@link javax.swing.JComboBox} and {@link javax.swing.JSpinner}<br>
+	 * <strong>Value type</strong> {@link java.lang.Boolean}
+	 *
+	 * @see #SELECT_ALL_ON_FOCUS_POLICY
+	 * @since 3.6
+	 */
+	String SELECT_ALL_ON_MOUSE_CLICK = "JTextField.selectAllOnMouseClick";
+
 	/**
 	 * Placeholder text that is only painted if the text field is empty.
 	 * <p>
@@ -1136,8 +1405,8 @@ public interface FlatClientProperties
 	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JToggleButton}<br>
 	 * <strong>Value type</strong> {@link java.lang.Integer}<br>
-	 * <strong>SupportedValues:</strong>
-	 *     {@link SwingConstants#BOTTOM} (default)
+	 * <strong>Allowed Values</strong>
+	 *     {@link SwingConstants#BOTTOM} (default),
 	 *     {@link SwingConstants#TOP},
 	 *     {@link SwingConstants#LEFT} or
 	 *     {@link SwingConstants#RIGHT}
@@ -1174,13 +1443,23 @@ public interface FlatClientProperties
 	//---- JTree --------------------------------------------------------------
 
 	/**
-	 * Override if a tree shows a wide selection. Default is {@code true}.
+	 * Specifies whether tree shows a wide selection. Default is {@code true}.
 	 * <p>
 	 * <strong>Component</strong> {@link javax.swing.JTree}<br>
 	 * <strong>Value type</strong> {@link java.lang.Boolean}
 	 */
 	String TREE_WIDE_SELECTION = "JTree.wideSelection";
 
+	/**
+	 * Specifies whether tree uses a wide cell renderer. Default is {@code false}.
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JTree}<br>
+	 * <strong>Value type</strong> {@link java.lang.Boolean}
+	 *
+	 * @since 3.6
+	 */
+	String TREE_WIDE_CELL_RENDERER = "JTree.wideCellRenderer";
+
 	/**
 	 * Specifies whether tree item selection is painted. Default is {@code true}.
 	 * If set to {@code false}, then the tree cell renderer is responsible for painting selection.
@@ -1191,6 +1470,44 @@ public interface FlatClientProperties
 	String TREE_PAINT_SELECTION = "JTree.paintSelection";
 
 
+	//---- macOS --------------------------------------------------------------
+
+	/**
+	 * Specifies the spacing around the macOS window close/minimize/zoom buttons.
+	 * Useful if <a href="https://www.formdev.com/flatlaf/macos/#full_window_content">full window content</a>
+	 * is enabled.
+	 * <p>
+	 * (requires macOS 10.14+ for "medium" spacing and macOS 11+ for "large" spacing, requires Java 17+)
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
+	 * <strong>Value type</strong> {@link java.lang.String}<br>
+	 * <strong>Allowed Values</strong>
+	 *     {@link #MACOS_WINDOW_BUTTONS_SPACING_MEDIUM} or
+	 *     {@link #MACOS_WINDOW_BUTTONS_SPACING_LARGE} (requires macOS 11+)
+	 *
+	 * @since 3.4
+	 */
+	String MACOS_WINDOW_BUTTONS_SPACING = "FlatLaf.macOS.windowButtonsSpacing";
+
+	/**
+	 * Add medium spacing around the macOS window close/minimize/zoom buttons.
+	 *
+	 * @see #MACOS_WINDOW_BUTTONS_SPACING
+	 * @since 3.4
+	 */
+	String MACOS_WINDOW_BUTTONS_SPACING_MEDIUM = "medium";
+
+	/**
+	 * Add large spacing around the macOS window close/minimize/zoom buttons.
+	 * <p>
+	 * (requires macOS 11+; "medium" is used on older systems)
+	 *
+	 * @see #MACOS_WINDOW_BUTTONS_SPACING
+	 * @since 3.4
+	 */
+	String MACOS_WINDOW_BUTTONS_SPACING_LARGE = "large";
+
+
 	//---- helper methods -----------------------------------------------------
 
 	/**

flatlaf-core/src/main/java/com/formdev/flatlaf/FlatDefaultsAddon.java

@@ -48,7 +48,7 @@ public abstract class FlatDefaultsAddon
 	public InputStream getDefaults( Class<?> lafClass ) {
 		Class<?> addonClass = this.getClass();
 		String propertiesName = '/' + addonClass.getPackage().getName().replace( '.', '/' )
-			+ '/' + lafClass.getSimpleName() + ".properties";
+			+ '/' + UIDefaultsLoader.simpleClassName( lafClass ) + ".properties";
 		return addonClass.getResourceAsStream( propertiesName );
 	}
 

flatlaf-core/src/main/java/com/formdev/flatlaf/FlatInputMaps.java

@@ -71,7 +71,7 @@ class FlatInputMaps
 			);
 		}
 
-		// join ltr and rtl bindings to fix up/down/etc keys in right-to-left component orientation
+		// join ltr and rtl bindings to fix up/down/etc. keys in right-to-left component orientation
 		Object[] bindings = (Object[]) defaults.get( "PopupMenu.selectedWindowInputMapBindings" );
 		Object[] rtlBindings = (Object[]) defaults.get( "PopupMenu.selectedWindowInputMapBindings.RightToLeft" );
 		if( bindings != null && rtlBindings != null ) {

flatlaf-core/src/main/java/com/formdev/flatlaf/FlatLaf.java

@@ -20,6 +20,7 @@ import java.awt.Color;
 import java.awt.Component;
 import java.awt.EventQueue;
 import java.awt.Font;
+import java.awt.GraphicsEnvironment;
 import java.awt.Image;
 import java.awt.RenderingHints;
 import java.awt.Toolkit;
@@ -30,15 +31,13 @@ import java.awt.image.ImageProducer;
 import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
 import java.io.File;
-import java.lang.invoke.MethodHandle;
-import java.lang.invoke.MethodHandles;
-import java.lang.invoke.MethodType;
 import java.lang.reflect.Method;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Enumeration;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -46,6 +45,7 @@ import java.util.MissingResourceException;
 import java.util.Properties;
 import java.util.ResourceBundle;
 import java.util.ServiceLoader;
+import java.util.Set;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.IntUnaryOperator;
@@ -78,6 +78,7 @@ import com.formdev.flatlaf.ui.FlatNativeWindowBorder;
 import com.formdev.flatlaf.ui.FlatPopupFactory;
 import com.formdev.flatlaf.ui.FlatRootPaneUI;
 import com.formdev.flatlaf.ui.FlatUIUtils;
+import com.formdev.flatlaf.ui.JavaCompatibility2;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
 import com.formdev.flatlaf.util.FontUtils;
 import com.formdev.flatlaf.util.GrayFilter;
@@ -101,6 +102,8 @@ public abstract class FlatLaf
 	private static Map<String, String> globalExtraDefaults;
 	private Map<String, String> extraDefaults;
 	private static Function<String, Color> systemColorGetter;
+	private static Set<String> uiKeyPlatformPrefixes;
+	private static Set<String> uiKeySpecialPrefixes;
 
 	private String desktopPropertyName;
 	private String desktopPropertyName2;
@@ -112,6 +115,7 @@ public abstract class FlatLaf
 	private PopupFactory oldPopupFactory;
 	private MnemonicHandler mnemonicHandler;
 	private boolean subMenuUsabilityHelperInstalled;
+	private LinuxPopupMenuCanceler linuxPopupMenuCanceler;
 
 	private Consumer<UIDefaults> postInitialization;
 	private List<Function<Object, Object>> uiDefaultsGetters;
@@ -121,6 +125,46 @@ public abstract class FlatLaf
 	private static String preferredSemiboldFontFamily;
 	private static String preferredMonospacedFontFamily;
 
+	static {
+		// see disableWindowsD3Donscreen() for details
+		// https://github.com/JFormDesigner/FlatLaf/issues/887
+		if( SystemInfo.isWindows &&
+			System.getProperty( "sun.java2d.d3d.onscreen" ) == null &&
+			System.getProperty( "sun.java2d.d3d" ) == null &&
+			System.getProperty( "sun.java2d.noddraw" ) == null )
+		  System.setProperty( "sun.java2d.d3d.onscreen", "false" );
+	}
+
+	/**
+	 * Disable usage of Windows Direct3D (DirectX) onscreen surfaces because this may lead to
+	 * repaint issues (ghosting) on some systems (probably depending on graphics card/driver).
+	 * Problem occurs usually when a small heavy-weight popup window (menu, combobox, tooltip) is shown.
+	 * <p>
+	 * Sets system property {@code sun.java2d.d3d.onscreen} to {@code false},
+	 * but only if {@code sun.java2d.d3d.onscreen}, {@code sun.java2d.d3d}
+	 * and {@code sun.java2d.noddraw} are not yet set.
+	 * <p>
+	 * <strong>Note</strong>: Must be invoked very early before the graphics environment is created.
+	 * <p>
+	 * This method is automatically invoked when loading this class,
+	 * which is usually before the graphics environment is created.
+	 * E.g. when doing {@code FlatLightLaf.setup()} or
+	 * {@code UIManager.setLookAndFeel( "com.formdev.flatlaf.FlatLightLaf" )}.
+	 * <p>
+	 * However, it may be invoked too late if you use some methods from {@link UIManager}
+	 * of {@link GraphicsEnvironment} before setting look and feel.
+	 * E.g. {@link UIManager#put(Object, Object)}.
+	 * In that case invoke this method yourself very early.
+	 * <p>
+	 * <strong>Tip</strong>: How to find out when the graphics environment is created?
+	 * Set a breakpoint at constructor of class {@link GraphicsEnvironment} and look at the stack.
+	 *
+	 * @since 3.5.2
+	 */
+	public static void disableWindowsD3Donscreen() {
+		// dummy method used to trigger invocation of "static {...}" block
+	}
+
 	/**
 	 * Sets the application look and feel to the given LaF
 	 * using {@link UIManager#setLookAndFeel(javax.swing.LookAndFeel)}.
@@ -183,17 +227,11 @@ public abstract class FlatLaf
 	 * This depends on the operating system and on the used Java runtime.
 	 * <p>
 	 * This method returns {@code true} on Windows 10/11 (see exception below)
-	 * and on Linux, {@code false} otherwise.
+	 * and on Linux, otherwise returns {@code false}.
+	 * <p>
+	 * Returns also {@code false} on Windows 10/11 if
+	 * FlatLaf native window border support is available (requires Windows 10/11).
 	 * <p>
-	 * Returns also {@code false} on Windows 10/11 if:
-	 * <ul>
-	 * <li>FlatLaf native window border support is available (requires Windows 10/11)</li>
-	 * <li>running in
-	 * <a href="https://confluence.jetbrains.com/display/JBR/JetBrains+Runtime">JetBrains Runtime 11 (or later)</a>
-	 * (<a href="https://github.com/JetBrains/JetBrainsRuntime">source code on github</a>)
-	 * and JBR supports custom window decorations
-	 * </li>
-	 * </ul>
 	 * In these cases, custom decorations are enabled by the root pane.
 	 * Usage of {@link JFrame#setDefaultLookAndFeelDecorated(boolean)} or
 	 * {@link JDialog#setDefaultLookAndFeelDecorated(boolean)} is not necessary.
@@ -272,6 +310,10 @@ public abstract class FlatLaf
 		// install submenu usability helper
 		subMenuUsabilityHelperInstalled = SubMenuUsabilityHelper.install();
 
+		// install Linux popup menu canceler
+		if( SystemInfo.isLinux )
+			linuxPopupMenuCanceler = new LinuxPopupMenuCanceler();
+
 		// listen to desktop property changes to update UI if system font or scaling changes
 		if( SystemInfo.isWindows ) {
 			// Windows 10 allows increasing font size independent of scaling:
@@ -364,6 +406,12 @@ public abstract class FlatLaf
 			subMenuUsabilityHelperInstalled = false;
 		}
 
+		// uninstall Linux popup menu canceler
+		if( linuxPopupMenuCanceler != null ) {
+			linuxPopupMenuCanceler.uninstall();
+			linuxPopupMenuCanceler = null;
+		}
+
 		// restore default link color
 		new HTMLEditorKit().getStyleSheet().addRule( "a, address { color: blue; }" );
 		postInitialization = null;
@@ -477,10 +525,10 @@ public abstract class FlatLaf
 
 		// load defaults from properties
 		List<Class<?>> lafClassesForDefaultsLoading = getLafClassesForDefaultsLoading();
-		if( lafClassesForDefaultsLoading != null )
-			UIDefaultsLoader.loadDefaultsFromProperties( lafClassesForDefaultsLoading, addons, getAdditionalDefaults(), isDark(), defaults );
-		else
-			UIDefaultsLoader.loadDefaultsFromProperties( getClass(), addons, getAdditionalDefaults(), isDark(), defaults );
+		if( lafClassesForDefaultsLoading == null )
+			lafClassesForDefaultsLoading = UIDefaultsLoader.getLafClassesForDefaultsLoading( getClass() );
+		UIDefaultsLoader.loadDefaultsFromProperties( lafClassesForDefaultsLoading, addons,
+			this::applyAdditionalProperties, getAdditionalDefaults(), isDark(), defaults );
 
 		// setup default font after loading defaults from properties
 		// to allow defining "defaultFont" in properties
@@ -497,9 +545,6 @@ public abstract class FlatLaf
 		// initialize text antialiasing
 		putAATextInfo( defaults );
 
-		// apply additional defaults (e.g. from IntelliJ themes)
-		applyAdditionalDefaults( defaults );
-
 		// allow addons modifying UI defaults
 		for( FlatDefaultsAddon addon : addons )
 			addon.afterDefaultsLoading( this, defaults );
@@ -509,6 +554,9 @@ public abstract class FlatLaf
 			return UIScale.getUserScaleFactor();
 		} );
 
+		// add lazy UI delegate class loading (if necessary)
+		addLazyUIdelegateClassLoading( defaults );
+
 		if( postInitialization != null ) {
 			postInitialization.accept( defaults );
 			postInitialization = null;
@@ -517,7 +565,8 @@ public abstract class FlatLaf
 		return defaults;
 	}
 
-	void applyAdditionalDefaults( UIDefaults defaults ) {
+	// apply additional properties (e.g. from IntelliJ themes)
+	void applyAdditionalProperties( Properties properties ) {
 	}
 
 	protected List<Class<?>> getLafClassesForDefaultsLoading() {
@@ -706,6 +755,53 @@ public abstract class FlatLaf
 		}
 	}
 
+	/**
+	 * Handle UI delegate classes if running in special application where multiple class loaders are involved.
+	 * E.g. in Eclipse plugin or in LibreOffice extension.
+	 * <p>
+	 * Problem: Swing runs in Java's system classloader and FlatLaf is loaded in plugin classloader.
+	 * When Swing tries to load UI delegate class in {@link UIDefaults#getUIClass(String, ClassLoader)},
+	 * invoked from {@link UIDefaults#getUI(JComponent)}, it uses the component's classloader,
+	 * which is Java's system classloader for core Swing components,
+	 * and can not find FlatLaf UI delegates.
+	 * <p>
+	 * Solution: Add lazy values for UI delegate class names.
+	 * Those lazy values use FlatLaf classloader to load UI delegate class.
+	 * This is similar to what {@link UIDefaults#getUIClass(String, ClassLoader)} does.
+	 * <p>
+	 * Not using {@code defaults.put( "ClassLoader", FlatLaf.class.getClassLoader() )},
+	 * which would work for FlatLaf UI delegates, but it would break custom
+	 * UI delegates used in other classloaders.
+	 */
+	private static void addLazyUIdelegateClassLoading( UIDefaults defaults ) {
+		if( FlatLaf.class.getClassLoader() == ClassLoader.getSystemClassLoader() )
+			return; // not necessary
+
+		Map<String, LazyValue> map = new HashMap<>();
+		for( Map.Entry<Object, Object> e : defaults.entrySet() ) {
+			Object key = e.getKey();
+			Object value = e.getValue();
+			if( key instanceof String && ((String)key).endsWith( "UI" ) &&
+				value instanceof String && !defaults.containsKey( value ) )
+			{
+				String className = (String) value;
+				map.put( className, (LazyValue) t -> {
+					try {
+						Class<?> uiClass = FlatLaf.class.getClassLoader().loadClass( className );
+						if( ComponentUI.class.isAssignableFrom( uiClass ) )
+							return uiClass;
+					} catch( ClassNotFoundException ex ) {
+						// ignore
+					}
+
+					// let UIDefaults.getUIClass() try to load UI delegate class
+					return null;
+				} );
+			}
+		}
+		defaults.putAll( map );
+	}
+
 	private void putAATextInfo( UIDefaults defaults ) {
 		if ( SystemInfo.isMacOS && SystemInfo.isJetBrainsJVM ) {
 			// The awt.font.desktophints property suggests sub-pixel anti-aliasing
@@ -815,8 +911,7 @@ public abstract class FlatLaf
 	 * <p>
 	 * Invoke this method before setting the look and feel.
 	 * <p>
-	 * If using Java modules, the package must be opened in {@code module-info.java}.
-	 * Otherwise, use {@link #registerCustomDefaultsSource(URL)}.
+	 * If using Java modules, it is not necessary to open the package in {@code module-info.java}.
 	 *
 	 * @param packageName a package name (e.g. "com.myapp.resources")
 	 */
@@ -863,9 +958,9 @@ public abstract class FlatLaf
 	 * <p>
 	 * See {@link #registerCustomDefaultsSource(String)} for details.
 	 * <p>
-	 * This method is useful if using Java modules and the package containing the properties files
-	 * is not opened in {@code module-info.java}.
 	 * E.g. {@code FlatLaf.registerCustomDefaultsSource( MyApp.class.getResource( "/com/myapp/themes/" ) )}.
+	 * <p>
+	 * If using Java modules, it is not necessary to open the package in {@code module-info.java}.
 	 *
 	 * @param packageUrl a package URL
 	 * @since 2
@@ -1030,6 +1125,92 @@ public abstract class FlatLaf
 		FlatLaf.systemColorGetter = systemColorGetter;
 	}
 
+	/**
+	 * Returns UI key prefix, used in FlatLaf properties files, for light or dark themes.
+	 * Return value is either {@code [light]} or {@code [dark]}.
+	 *
+	 * @since 3.6
+	 */
+	public static String getUIKeyLightOrDarkPrefix( boolean dark ) {
+		return dark ? "[dark]" : "[light]";
+	}
+
+	/**
+	 * Returns set of UI key prefixes, used in FlatLaf properties files, for current platform.
+	 * If UI keys in properties files start with a prefix (e.g. {@code [someprefix]Button.background}),
+	 * then they are only used if that prefix is contained in this set
+	 * (or is one of {@code [light]} or {@code [dark]} depending on current theme).
+	 * <p>
+	 * By default, the set contains one or more of following prefixes:
+	 * <ul>
+	 *   <li>{@code [win]} on Windows
+	 *   <li>{@code [mac]} on macOS
+	 *   <li>{@code [linux]} on Linux
+	 *   <li>{@code [unknown]} on other platforms
+	 *   <li>{@code [gnome]} on Linux with GNOME desktop environment
+	 *   <li>{@code [kde]} on Linux with KDE desktop environment
+	 *   <li>on Linux, the value of the environment variable {@code XDG_CURRENT_DESKTOP},
+	 *       split at colons and converted to lower case (e.g. if value of  {@code XDG_CURRENT_DESKTOP}
+	 *       is {@code ubuntu:GNOME}, then {@code [ubuntu]} and {@code [gnome]})
+	 * </ul>
+	 * <p>
+	 * You can add own prefixes to the set.
+	 * The prefixes must start with '[' and end with ']' characters, otherwise they will be ignored.
+	 *
+	 * @since 3.6
+	 */
+	public static Set<String> getUIKeyPlatformPrefixes() {
+		if( uiKeyPlatformPrefixes == null ) {
+			uiKeyPlatformPrefixes = new HashSet<>();
+			uiKeyPlatformPrefixes.add(
+				SystemInfo.isWindows ? "[win]" :
+				SystemInfo.isMacOS ? "[mac]" :
+				SystemInfo.isLinux ? "[linux]" : "[unknown]" );
+
+			// Linux
+			if( SystemInfo.isLinux ) {
+				if( SystemInfo.isGNOME )
+					uiKeyPlatformPrefixes.add( "[gnome]" );
+				else if( SystemInfo.isKDE )
+					uiKeyPlatformPrefixes.add( "[kde]" );
+
+				// add values from XDG_CURRENT_DESKTOP for other desktops
+				String desktop = System.getenv( "XDG_CURRENT_DESKTOP" );
+				if( desktop != null ) {
+					// XDG_CURRENT_DESKTOP is a colon-separated list of strings
+					// https://specifications.freedesktop.org/desktop-entry-spec/latest/recognized-keys.html#key-onlyshowin
+					// e.g. "ubuntu:GNOME" on Ubuntu 24.10 or "GNOME-Classic:GNOME" on CentOS 7
+					for( String desk : StringUtils.split( desktop.toLowerCase( Locale.ENGLISH ), ':', true, true ) )
+						uiKeyPlatformPrefixes.add( '[' + desk + ']' );
+				}
+			}
+		}
+		return uiKeyPlatformPrefixes;
+	}
+
+	/**
+	 * Returns set of special UI key prefixes, used in FlatLaf properties files.
+	 * Unlike other prefixes, properties with special prefixes are preserved.
+	 * You can access them using `UIManager`. E.g. `UIManager.get( "[someSpecialPrefix]someKey" )`.
+	 * <p>
+	 * By default, the set contains following special prefixes:
+	 * <ul>
+	 *   <li>{@code [style]}
+	 * </ul>
+	 * <p>
+	 * You can add own prefixes to the set.
+	 * The prefixes must start with '[' and end with ']' characters, otherwise they will be ignored.
+	 *
+	 * @since 3.6
+	 */
+	public static Set<String> getUIKeySpecialPrefixes() {
+		if( uiKeySpecialPrefixes == null ) {
+			uiKeySpecialPrefixes = new HashSet<>();
+			uiKeySpecialPrefixes.add( "[style]" );
+		}
+		return uiKeySpecialPrefixes;
+	}
+
 	private static void reSetLookAndFeel() {
 		EventQueue.invokeLater( () -> {
 			LookAndFeel lookAndFeel = UIManager.getLookAndFeel();
@@ -1295,8 +1476,8 @@ public abstract class FlatLaf
 	 * @since 2.5
 	 */
 	public static Map<String, Class<?>> getStyleableInfos( JComponent c ) {
-		StyleableUI ui = getStyleableUI( c );
-		return (ui != null) ? ui.getStyleableInfos( c ) : null;
+		ComponentUI ui = JavaCompatibility2.getUI( c );
+		return (ui instanceof StyleableUI) ? ((StyleableUI)ui).getStyleableInfos( c ) : null;
 	}
 
 	/**
@@ -1308,41 +1489,10 @@ public abstract class FlatLaf
 	 */
 	@SuppressWarnings( "unchecked" )
 	public static <T> T getStyleableValue( JComponent c, String key ) {
-		StyleableUI ui = getStyleableUI( c );
-		return (ui != null) ? (T) ui.getStyleableValue( c, key ) : null;
+		ComponentUI ui = JavaCompatibility2.getUI( c );
+		return (ui instanceof StyleableUI) ? (T) ((StyleableUI)ui).getStyleableValue( c, key ) : null;
 	}
 
-	private static StyleableUI getStyleableUI( JComponent c ) {
-		if( !getUIMethodInitialized ) {
-			getUIMethodInitialized = true;
-
-			if( SystemInfo.isJava_9_orLater ) {
-				try {
-					// JComponent.getUI() is available since Java 9
-					getUIMethod = MethodHandles.lookup().findVirtual( JComponent.class, "getUI",
-						MethodType.methodType( ComponentUI.class ) );
-				} catch( Exception ex ) {
-					// ignore
-				}
-			}
-		}
-
-		try {
-			Object ui;
-			if( getUIMethod != null )
-				ui = getUIMethod.invoke( c );
-			else
-				ui = c.getClass().getMethod( "getUI" ).invoke( c );
-			return (ui instanceof StyleableUI) ? (StyleableUI) ui : null;
-		} catch( Throwable ex ) {
-			// ignore
-			return null;
-		}
-	}
-
-	private static boolean getUIMethodInitialized;
-	private static MethodHandle getUIMethod;
-
 	/**
 	 * Returns the preferred font family to be used for (nearly) all fonts; or {@code null}.
 	 *

flatlaf-core/src/main/java/com/formdev/flatlaf/FlatPropertiesLaf.java

@@ -20,16 +20,21 @@ import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Locale;
 import java.util.Properties;
+import com.formdev.flatlaf.themes.FlatMacDarkLaf;
+import com.formdev.flatlaf.themes.FlatMacLightLaf;
 
 /**
  * A Flat LaF that is able to load UI defaults from properties passed to the constructor.
  * <p>
  * Specify the base theme in the properties with {@code @baseTheme=<baseTheme>}.
  * Allowed values for {@code <baseTheme>} are {@code light} (the default), {@code dark},
- * {@code intellij} or {@code darcula}.
+ * {@code intellij}, {@code darcula}, {@code maclight} or {@code macdark}.
  * <p>
  * The properties are applied after loading the base theme and may overwrite base properties.
  * All features of FlatLaf properties files are available.
@@ -60,8 +65,8 @@ public class FlatPropertiesLaf
 		throws IOException
 	{
 		Properties properties = new Properties();
-		try( InputStream in2 = in ) {
-			properties.load( in2 );
+		try( Reader reader = new InputStreamReader( in, StandardCharsets.UTF_8 )) {
+			properties.load( reader );
 		}
 		return properties;
 	}
@@ -71,7 +76,8 @@ public class FlatPropertiesLaf
 		this.properties = properties;
 
 		baseTheme = properties.getProperty( "@baseTheme", "light" );
-		dark = "dark".equalsIgnoreCase( baseTheme ) || "darcula".equalsIgnoreCase( baseTheme );
+		dark = "dark".equalsIgnoreCase( baseTheme ) || "darcula".equalsIgnoreCase( baseTheme ) ||
+			"macdark".equalsIgnoreCase( baseTheme );
 	}
 
 	@Override
@@ -116,6 +122,16 @@ public class FlatPropertiesLaf
 				lafClasses.add( FlatDarkLaf.class );
 				lafClasses.add( FlatDarculaLaf.class );
 				break;
+
+			case "maclight":
+				lafClasses.add( FlatLightLaf.class );
+				lafClasses.add( FlatMacLightLaf.class );
+				break;
+
+			case "macdark":
+				lafClasses.add( FlatDarkLaf.class );
+				lafClasses.add( FlatMacDarkLaf.class );
+				break;
 		}
 		return lafClasses;
 	}

flatlaf-core/src/main/java/com/formdev/flatlaf/FlatSystemProperties.java

@@ -16,6 +16,7 @@
 
 package com.formdev.flatlaf;
 
+import javax.swing.JPopupMenu;
 import javax.swing.SwingUtilities;
 import com.formdev.flatlaf.util.UIScale;
 
@@ -82,7 +83,7 @@ public interface FlatSystemProperties
 	 * {@link FlatClientProperties#USE_WINDOW_DECORATIONS} and
 	 * UI default {@code TitlePane.useWindowDecorations}.
 	 * <p>
-	 * (requires Window 10/11)
+	 * (requires Windows 10/11)
 	 * <p>
 	 * <strong>Allowed Values</strong> {@code false} and {@code true}<br>
 	 * <strong>Default</strong> none
@@ -99,11 +100,14 @@ public interface FlatSystemProperties
 	 * Setting this to {@code false} disables using JetBrains Runtime custom window decorations.
 	 * Then FlatLaf native window decorations are used.
 	 * <p>
-	 * (requires Window 10/11)
+	 * (requires Windows 10/11)
 	 * <p>
 	 * <strong>Allowed Values</strong> {@code false} and {@code true}<br>
 	 * <strong>Default</strong> {@code false} (since v2; was {@code true} in v1)
+	 *
+	 * @deprecated No longer used since FlatLaf 3.3. Retained for API compatibility.
 	 */
+	@Deprecated
 	String USE_JETBRAINS_CUSTOM_DECORATIONS = "flatlaf.useJetBrainsCustomDecorations";
 
 	/**
@@ -117,7 +121,7 @@ public interface FlatSystemProperties
 	 * {@link FlatClientProperties#MENU_BAR_EMBEDDED} and
 	 * UI default {@code TitlePane.menuBarEmbedded}.
 	 * <p>
-	 * (requires Window 10/11)
+	 * (requires Windows 10/11)
 	 * <p>
 	 * <strong>Allowed Values</strong> {@code false} and {@code true}<br>
 	 * <strong>Default</strong> none
@@ -132,6 +136,37 @@ public interface FlatSystemProperties
 	 */
 	String ANIMATION = "flatlaf.animation";
 
+	/**
+	 * Specifies whether native rounded popup borders should be used (if supported by operating system).
+	 * <p>
+	 * (requires Windows 11 or macOS)
+	 * <p>
+	 * <strong>Allowed Values</strong> {@code false} and {@code true}<br>
+	 * <strong>Default</strong> {@code true}; except in FlatLaf 3.5.x on macOS 14.4+ where it was {@code false}
+	 *
+	 * @since 3.5.2
+	 */
+	String USE_ROUNDED_POPUP_BORDER = "flatlaf.useRoundedPopupBorder";
+
+	/**
+	 * Species whether popup windows may be reused without (temporary) hiding them.
+	 * E.g. if "moving" a tooltip to follow the mouse pointer, normally it is necessary
+	 * to hide the tooltip and show it again at the new location, which causes some
+	 * flicker with heavy-weight popup windows that FlatLaf uses on all platforms.
+	 * <p>
+	 * If {@code true}, hiding popup window is deferred for an event cycle,
+	 * which allows reusing still visible popup window and avoids flicker when "moving" the popup.
+	 * <p>
+	 * Note that {@link JPopupMenu} popup windows (menus and combobox lists) are newer reused.
+	 * <p>
+	 * <strong>Allowed Values</strong> {@code false} and {@code true}<br>
+	 * <strong>Default</strong> {@code true}
+	 *
+	 * @since 3.6.2
+	 */
+	String REUSE_VISIBLE_POPUP_WINDOW = "flatlaf.reuseVisiblePopupWindow";
+
+
 	/**
 	 * Specifies whether vertical text position is corrected when UI is scaled on HiDPI screens.
 	 * <p>
@@ -169,24 +204,48 @@ public interface FlatSystemProperties
 	String USE_NATIVE_LIBRARY = "flatlaf.useNativeLibrary";
 
 	/**
-	 * Specifies a directory in which the native FlatLaf libraries have been extracted.
+	 * Specifies a directory in which the FlatLaf native libraries are searched for.
 	 * The path can be absolute or relative to current application working directory.
 	 * This can be used to avoid extraction of the native libraries to the temporary directory at runtime.
 	 * <p>
-	 * If the value is {@code "system"}, then {@link System#loadLibrary(String)} is
-	 * used to load the native library.
-	 * Searches for the native library in classloader of caller
+	 * If the value is {@code "system"} (supported since FlatLaf 2.6),
+	 * then {@link System#loadLibrary(String)} is used to load the native library.
+	 * This searches for the native library in classloader of caller
 	 * (using {@link ClassLoader#findLibrary(String)}) and in paths specified
 	 * in system properties {@code sun.boot.library.path} and {@code java.library.path}.
-	 * (supported since FlatLaf 2.6)
 	 * <p>
-	 * If the native library can not loaded from the given path (or via {@link System#loadLibrary(String)}),
+	 * If the native library can not be loaded from the given path (or via {@link System#loadLibrary(String)}),
 	 * then the embedded native library is extracted to the temporary directory and loaded from there.
+	 * <p>
+	 * The file names of the native libraries must be either:
+	 * <ul>
+	 *   <li>the same as in flatlaf.jar in package 'com/formdev/flatlaf/natives' (required for "system") or
+	 *   <li>when downloaded from Maven central then as described here:
+	 *     <a href="https://www.formdev.com/flatlaf/native-libraries/">https://www.formdev.com/flatlaf/native-libraries/</a>
+	 *     (requires FlatLaf 3.4)
+	 * </ul>
+	 * <p>
+	 * <strong>Note</strong>: Since FlatLaf 3.1 it is recommended to download the
+	 * FlatLaf native libraries from Maven central and distribute them with your
+	 * application in the same directory as flatlaf.jar.
+	 * Then it is <strong>not necessary</strong> to set this system property.
+	 * See <a href="https://www.formdev.com/flatlaf/native-libraries/">https://www.formdev.com/flatlaf/native-libraries/</a>
+	 * for details.
 	 *
 	 * @since 2
 	 */
 	String NATIVE_LIBRARY_PATH = "flatlaf.nativeLibraryPath";
 
+	/**
+	 * Specifies whether safe triangle is used to improve usability of submenus.
+	 * <p>
+	 * <strong>Allowed Values</strong> {@code false} and {@code true}<br>
+	 * <strong>Default</strong> {@code true}
+	 *
+	 * @since 3.5.1
+	 */
+	String USE_SUB_MENU_SAFE_TRIANGLE = "flatlaf.useSubMenuSafeTriangle";
+
 	/**
 	 * Checks whether a system property is set and returns {@code true} if its value
 	 * is {@code "true"} (case-insensitive), otherwise it returns {@code false}.

flatlaf-core/src/main/java/com/formdev/flatlaf/IntelliJTheme.java

@@ -16,7 +16,6 @@
 
 package com.formdev.flatlaf;
 
-import java.awt.Color;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
@@ -25,20 +24,16 @@ import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
-import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Properties;
 import java.util.Set;
-import java.util.Map.Entry;
-import javax.swing.UIDefaults;
-import javax.swing.plaf.ColorUIResource;
 import com.formdev.flatlaf.json.Json;
 import com.formdev.flatlaf.json.ParseException;
-import com.formdev.flatlaf.util.ColorFunctions;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.StringUtils;
 import com.formdev.flatlaf.util.SystemInfo;
@@ -63,13 +58,11 @@ public class IntelliJTheme
 	public final boolean dark;
 	public final String author;
 
-	private final boolean isMaterialUILite;
+	private Map<String, String> jsonColors;
+	private Map<String, Object> jsonUI;
+	private Map<String, Object> jsonIcons;
 
-	private Map<String, String> colors;
-	private Map<String, Object> ui;
-	private Map<String, Object> icons;
-
-	private Map<String, ColorUIResource> namedColors = Collections.emptyMap();
+	private Map<String, String> namedColors = Collections.emptyMap();
 
 	/**
 	 * Loads a IntelliJ .theme.json file from the given input stream,
@@ -138,94 +131,90 @@ public class IntelliJTheme
 	    dark = Boolean.parseBoolean( (String) json.get( "dark" ) );
 	    author = (String) json.get( "author" );
 
-		isMaterialUILite = author.equals( "Mallowigi" );
-
-	    colors = (Map<String, String>) json.get( "colors" );
-	    ui = (Map<String, Object>) json.get( "ui" );
-	    icons = (Map<String, Object>) json.get( "icons" );
+	    jsonColors = (Map<String, String>) json.get( "colors" );
+	    jsonUI = (Map<String, Object>) json.get( "ui" );
+	    jsonIcons = (Map<String, Object>) json.get( "icons" );
 	}
 
-	private void applyProperties( UIDefaults defaults ) {
-		if( ui == null )
+	private void applyProperties( Properties properties ) {
+		if( jsonUI == null )
 			return;
 
-		defaults.put( "Component.isIntelliJTheme", true );
+		put( properties, "Component.isIntelliJTheme", "true" );
 
 		// enable button shadows
-		defaults.put( "Button.paintShadow", true );
-		defaults.put( "Button.shadowWidth", dark ? 2 : 1 );
+		put( properties, "Button.paintShadow", "true" );
+		put( properties, "Button.shadowWidth", dark ? "2" : "1" );
 
-		Map<Object, Object> themeSpecificDefaults = removeThemeSpecificDefaults( defaults );
+		Map<String, String> themeSpecificProps = removeThemeSpecificProps( properties );
+		Set<String> jsonUIKeys = new HashSet<>();
 
-		loadNamedColors( defaults );
+		// Json node "colors"
+		loadNamedColors( properties, jsonUIKeys );
 
-		// convert Json "ui" structure to UI defaults
-		ArrayList<Object> defaultsKeysCache = new ArrayList<>();
-		Set<String> uiKeys = new HashSet<>();
-		for( Map.Entry<String, Object> e : ui.entrySet() )
-			apply( e.getKey(), e.getValue(), defaults, defaultsKeysCache, uiKeys );
+		// convert Json "ui" structure to UI properties
+		for( Map.Entry<String, Object> e : jsonUI.entrySet() )
+			apply( e.getKey(), e.getValue(), properties, jsonUIKeys );
 
-		applyColorPalette( defaults );
-		applyCheckBoxColors( defaults );
+		// set FlatLaf variables
+		copyIfSetInJson( properties, jsonUIKeys, "@background", "Panel.background", "*.background" );
+		copyIfSetInJson( properties, jsonUIKeys, "@foreground", "CheckBox.foreground", "*.foreground" );
+		copyIfSetInJson( properties, jsonUIKeys, "@accentBaseColor",
+			"ColorPalette.accent", // Material UI Lite, Hiberbee
+			"ColorPalette.accentColor", // Dracula, One Dark
+			"ProgressBar.foreground",
+			"*.selectionBackground" );
+		copyIfSetInJson( properties, jsonUIKeys, "@accentUnderlineColor", "*.underlineColor", "TabbedPane.underlineColor" );
+		copyIfSetInJson( properties, jsonUIKeys, "@selectionBackground", "*.selectionBackground" );
+		copyIfSetInJson( properties, jsonUIKeys, "@selectionForeground", "*.selectionForeground" );
+		copyIfSetInJson( properties, jsonUIKeys, "@selectionInactiveBackground", "*.selectionInactiveBackground" );
+		copyIfSetInJson( properties, jsonUIKeys, "@selectionInactiveForeground", "*.selectionInactiveForeground" );
+
+		// Json node "icons/ColorPalette"
+		applyIconsColorPalette( properties );
+
+		// apply "CheckBox.icon." colors
+		applyCheckBoxColors( properties );
 
 		// copy values
 		for( Map.Entry<String, String> e : uiKeyCopying.entrySet() ) {
-			Object value = defaults.get( e.getValue() );
+			Object value = properties.get( e.getValue() );
 			if( value != null )
-				defaults.put( e.getKey(), value );
+				put( properties, e.getKey(), value );
 		}
 
 		// IDEA does not paint button background if disabled, but FlatLaf does
-		Object panelBackground = defaults.get( "Panel.background" );
-		defaults.put( "Button.disabledBackground", panelBackground );
-		defaults.put( "ToggleButton.disabledBackground", panelBackground );
+		put( properties, "Button.disabledBackground", "@disabledBackground" );
+		put( properties, "ToggleButton.disabledBackground", "@disabledBackground" );
 
-		// fix Button borders
-		copyIfNotSet( defaults, "Button.focusedBorderColor", "Component.focusedBorderColor", uiKeys );
-		defaults.put( "Button.hoverBorderColor", defaults.get( "Button.focusedBorderColor" ) );
-		defaults.put( "HelpButton.hoverBorderColor", defaults.get( "Button.focusedBorderColor" ) );
-
-		// IDEA uses an SVG icon for the help button, but paints the background with Button.startBackground and Button.endBackground
-		Object helpButtonBackground = defaults.get( "Button.startBackground" );
-		Object helpButtonBorderColor = defaults.get( "Button.startBorderColor" );
-		if( helpButtonBackground == null )
-			helpButtonBackground = defaults.get( "Button.background" );
-		if( helpButtonBorderColor == null )
-			helpButtonBorderColor = defaults.get( "Button.borderColor" );
-		defaults.put( "HelpButton.background", helpButtonBackground );
-		defaults.put( "HelpButton.borderColor", helpButtonBorderColor );
-		defaults.put( "HelpButton.disabledBackground", panelBackground );
-		defaults.put( "HelpButton.disabledBorderColor", defaults.get( "Button.disabledBorderColor" ) );
-		defaults.put( "HelpButton.focusedBorderColor", defaults.get( "Button.focusedBorderColor" ) );
-		defaults.put( "HelpButton.focusedBackground", defaults.get( "Button.focusedBackground" ) );
+		// fix Button
+		fixStartEnd( properties, jsonUIKeys, "Button.startBackground", "Button.endBackground", "Button.background" );
+		fixStartEnd( properties, jsonUIKeys, "Button.startBorderColor", "Button.endBorderColor", "Button.borderColor" );
+		fixStartEnd( properties, jsonUIKeys, "Button.default.startBackground", "Button.default.endBackground", "Button.default.background" );
+		fixStartEnd( properties, jsonUIKeys, "Button.default.startBorderColor", "Button.default.endBorderColor", "Button.default.borderColor" );
 
 		// IDEA uses TextField.background for editable ComboBox and Spinner
-		Object textFieldBackground = get( defaults, themeSpecificDefaults, "TextField.background" );
-		defaults.put( "ComboBox.editableBackground", textFieldBackground );
-		defaults.put( "Spinner.background", textFieldBackground );
-
-		// Spinner arrow button always has same colors as ComboBox arrow button
-		defaults.put( "Spinner.buttonBackground", defaults.get( "ComboBox.buttonEditableBackground" ) );
-		defaults.put( "Spinner.buttonArrowColor", defaults.get( "ComboBox.buttonArrowColor" ) );
-		defaults.put( "Spinner.buttonDisabledArrowColor", defaults.get( "ComboBox.buttonDisabledArrowColor" ) );
+		Object textFieldBackground = get( properties, themeSpecificProps, "TextField.background" );
+		put( properties, "ComboBox.editableBackground", textFieldBackground );
+		put( properties, "Spinner.background", textFieldBackground );
 
 		// some themes specify colors for TextField.background, but forget to specify it for other components
 		// (probably because those components are not used in IntelliJ IDEA)
-		putAll( defaults, textFieldBackground,
+		putAll( properties, textFieldBackground,
 			"EditorPane.background",
 			"FormattedTextField.background",
 			"PasswordField.background",
 			"TextArea.background",
 			"TextPane.background"
 		);
-		putAll( defaults, get( defaults, themeSpecificDefaults, "TextField.selectionBackground" ),
+		putAll( properties, get( properties, themeSpecificProps, "TextField.selectionBackground" ),
 			"EditorPane.selectionBackground",
 			"FormattedTextField.selectionBackground",
 			"PasswordField.selectionBackground",
 			"TextArea.selectionBackground",
 			"TextPane.selectionBackground"
 		);
-		putAll( defaults, get( defaults, themeSpecificDefaults, "TextField.selectionForeground" ),
+		putAll( properties, get( properties, themeSpecificProps, "TextField.selectionForeground" ),
 			"EditorPane.selectionForeground",
 			"FormattedTextField.selectionForeground",
 			"PasswordField.selectionForeground",
@@ -235,7 +224,7 @@ public class IntelliJTheme
 
 		// fix disabled and not-editable backgrounds for text components, combobox and spinner
 		// (IntelliJ IDEA does not use those colors; instead it used background color of parent)
-		putAll( defaults, panelBackground,
+		putAll( properties, "@disabledBackground",
 			"ComboBox.disabledBackground",
 			"EditorPane.disabledBackground", "EditorPane.inactiveBackground",
 			"FormattedTextField.disabledBackground", "FormattedTextField.inactiveBackground",
@@ -246,132 +235,148 @@ public class IntelliJTheme
 			"TextPane.disabledBackground", "TextPane.inactiveBackground"
 		);
 
-		// fix ToggleButton
-		if( !uiKeys.contains( "ToggleButton.startBackground" ) && !uiKeys.contains( "*.startBackground" ) )
-			defaults.put( "ToggleButton.startBackground", defaults.get( "Button.startBackground" ) );
-		if( !uiKeys.contains( "ToggleButton.endBackground" ) && !uiKeys.contains( "*.endBackground" ) )
-			defaults.put( "ToggleButton.endBackground", defaults.get( "Button.endBackground" ) );
-		if( !uiKeys.contains( "ToggleButton.foreground" ) && uiKeys.contains( "Button.foreground" ) )
-			defaults.put( "ToggleButton.foreground", defaults.get( "Button.foreground" ) );
-
 		// fix DesktopPane background (use Panel.background and make it 5% darker/lighter)
-		Color desktopBackgroundBase = defaults.getColor( "Panel.background" );
-		Color desktopBackground = ColorFunctions.applyFunctions( desktopBackgroundBase,
-			new ColorFunctions.HSLIncreaseDecrease( 2, dark, 5, false, true ) );
-		defaults.put( "Desktop.background", new ColorUIResource( desktopBackground ) );
-
-		// fix List and Table background colors in Material UI Lite themes
-		if( isMaterialUILite ) {
-			defaults.put( "List.background", defaults.get( "Tree.background" ) );
-			defaults.put( "Table.background", defaults.get( "Tree.background" ) );
-		}
+		put( properties, "Desktop.background", dark ? "lighten($Panel.background,5%)" : "darken($Panel.background,5%)" );
 
 		// limit tree row height
-		int rowHeight = defaults.getInt( "Tree.rowHeight" );
+		String rowHeightStr = (String) properties.get( "Tree.rowHeight" );
+		int rowHeight = (rowHeightStr != null) ? Integer.parseInt( rowHeightStr ) : 0;
 		if( rowHeight > 22 )
-			defaults.put( "Tree.rowHeight", 22 );
+			put( properties, "Tree.rowHeight", "22" );
 
-		// get (and remove) theme specific wildcard replacements, which override all other defaults that end with same suffix
-		HashMap<String, Object> wildcards = new HashMap<>();
-		Iterator<Entry<Object, Object>> it = themeSpecificDefaults.entrySet().iterator();
+		// get (and remove) theme specific wildcard replacements, which override all other properties that end with same suffix
+		HashMap<String, String> wildcardProps = new HashMap<>();
+		Iterator<Map.Entry<String, String>> it = themeSpecificProps.entrySet().iterator();
 		while( it.hasNext() ) {
-			Entry<Object, Object> e = it.next();
-			String key = (String) e.getKey();
+			Map.Entry<String, String> e = it.next();
+			String key = e.getKey();
 			if( key.startsWith( "*." ) ) {
-				wildcards.put( key.substring( "*.".length() ), e.getValue() );
+				wildcardProps.put( key, e.getValue() );
 				it.remove();
 			}
 		}
 
-		// override UI defaults with theme specific wildcard replacements
-		if( !wildcards.isEmpty() ) {
-			for( Object key : defaults.keySet().toArray() ) {
-				int dot;
-				if( !(key instanceof String) ||
-					(dot = ((String)key).lastIndexOf( '.' )) < 0 )
-				  continue;
-
-				String wildcardKey = ((String)key).substring( dot + 1 );
-				Object wildcardValue = wildcards.get( wildcardKey );
-				if( wildcardValue != null )
-					defaults.put( key, wildcardValue );
-			}
+		// override properties with theme specific wildcard replacements
+		if( !wildcardProps.isEmpty() ) {
+			for( Map.Entry<String, String> e : wildcardProps.entrySet() )
+				applyWildcard( properties, e.getKey(), e.getValue() );
 		}
 
-		// apply theme specific UI defaults at the end to allow overwriting
-		for( Map.Entry<Object, Object> e : themeSpecificDefaults.entrySet() ) {
-			Object key = e.getKey();
-			Object value = e.getValue();
+		// apply theme specific properties at the end to allow overwriting
+		for( Map.Entry<String, String> e : themeSpecificProps.entrySet() ) {
+			String key = e.getKey();
+			String value = e.getValue();
 
 			// append styles to existing styles
-			if( key instanceof String && ((String)key).startsWith( "[style]" ) ) {
-				Object oldValue = defaults.get( key );
+			if( key.startsWith( "[style]" ) ) {
+				String oldValue = (String) properties.get( key );
 				if( oldValue != null )
 					value = oldValue + "; " + value;
 			}
 
-			defaults.put( key, value );
+			put( properties, key, value );
 		}
 
 		// let Java release memory
-		colors = null;
-		ui = null;
-		icons = null;
+		jsonColors = null;
+		jsonUI = null;
+		jsonIcons = null;
 	}
 
-	private Object get( UIDefaults defaults, Map<Object, Object> themeSpecificDefaults, String key ) {
-		return themeSpecificDefaults.getOrDefault( key, defaults.get( key ) );
+	private String get( Properties properties, Map<String, String> themeSpecificProps, String key ) {
+		return themeSpecificProps.getOrDefault( key, (String) properties.get( key ) );
 	}
 
-	private void putAll( UIDefaults defaults, Object value, String... keys ) {
+	private void put( Properties properties, Object key, Object value ) {
+		if( value != null )
+			properties.put( key, value );
+		else
+			properties.remove( key );
+	}
+
+	private void putAll( Properties properties, Object value, String... keys ) {
 		for( String key : keys )
-			defaults.put( key, value );
+			put( properties, key, value );
 	}
 
-	private Map<Object, Object> removeThemeSpecificDefaults( UIDefaults defaults ) {
-		// search for theme specific UI defaults keys
+	private void copyIfSetInJson( Properties properties, Set<String> jsonUIKeys, String destKey, String... srcKeys ) {
+		for( String srcKey : srcKeys ) {
+			if( jsonUIKeys.contains( srcKey ) ) {
+				Object value = properties.get( srcKey );
+				if( value != null ) {
+					put( properties, destKey, value );
+					break;
+				}
+			}
+		}
+	}
+
+	private void fixStartEnd( Properties properties, Set<String> jsonUIKeys, String startKey, String endKey, String key ) {
+		if( jsonUIKeys.contains( startKey ) && jsonUIKeys.contains( endKey ) )
+			put( properties, key, "$" + startKey );
+	}
+
+	private Map<String, String> removeThemeSpecificProps( Properties properties ) {
+		// search for theme specific properties keys
 		ArrayList<String> themeSpecificKeys = new ArrayList<>();
-		for( Object key : defaults.keySet() ) {
-			if( key instanceof String && ((String)key).startsWith( "[" ) && !((String)key).startsWith( "[style]" ) )
+		for( Object key : properties.keySet() ) {
+			if( ((String)key).startsWith( "{" ) )
 				themeSpecificKeys.add( (String) key );
 		}
 
-		// remove theme specific UI defaults and remember only those for current theme
-		Map<Object, Object> themeSpecificDefaults = new HashMap<>();
-		String currentThemePrefix = '[' + name.replace( ' ', '_' ) + ']';
-		String currentThemeAndAuthorPrefix = '[' + name.replace( ' ', '_' ) + "---" + author.replace( ' ', '_' ) + ']';
-		String currentAuthorPrefix = "[author-" + author.replace( ' ', '_' ) + ']';
-		String allThemesPrefix = "[*]";
-		String[] prefixes = { currentThemePrefix, currentThemeAndAuthorPrefix, currentAuthorPrefix, allThemesPrefix };
+		// special prefixes (priority from highest to lowest)
+		String currentThemePrefix = '{' + name.replace( ' ', '_' ) + '}';
+		String currentThemeAndAuthorPrefix = '{' + name.replace( ' ', '_' ) + "---" + author.replace( ' ', '_' ) + '}';
+		String currentAuthorPrefix = "{author-" + author.replace( ' ', '_' ) + '}';
+		String lightOrDarkPrefix = dark ? "{*-dark}" : "{*-light}";
+		String allThemesPrefix = "{*}";
+		String[] prefixes = { currentThemePrefix, currentThemeAndAuthorPrefix, currentAuthorPrefix, lightOrDarkPrefix, allThemesPrefix };
+
+		// collect values for special prefixes in its own maps
+		@SuppressWarnings( "unchecked" )
+		Map<String, String>[] maps = new Map[prefixes.length];
+		for( int i = 0; i < maps.length; i++ )
+			maps[i] = new HashMap<>();
+
+		// remove theme specific properties and remember only those for current theme
 		for( String key : themeSpecificKeys ) {
-			Object value = defaults.remove( key );
-			for( String prefix : prefixes ) {
+			String value = (String) properties.remove( key );
+			for( int i = 0; i < prefixes.length; i++ ) {
+				String prefix = prefixes[i];
 				if( key.startsWith( prefix ) ) {
-					themeSpecificDefaults.put( key.substring( prefix.length() ), value );
+					maps[i].put( key.substring( prefix.length() ), value );
 					break;
 				}
 			}
 		}
 
-		return themeSpecificDefaults;
+		// copy values into single map (from lowest to highest priority)
+		Map<String, String> themeSpecificProps = new HashMap<>();
+		for( int i = maps.length - 1; i >= 0; i-- )
+			themeSpecificProps.putAll( maps[i] );
+		return themeSpecificProps;
 	}
 
 	/**
 	 * http://www.jetbrains.org/intellij/sdk/docs/reference_guide/ui_themes/themes_customize.html#defining-named-colors
 	 */
-	private void loadNamedColors( UIDefaults defaults ) {
-		if( colors == null )
+	private void loadNamedColors( Properties properties, Set<String> jsonUIKeys ) {
+		if( jsonColors == null )
 			return;
 
 		namedColors = new HashMap<>();
 
-		for( Map.Entry<String, String> e : colors.entrySet() ) {
+		for( Map.Entry<String, String> e : jsonColors.entrySet() ) {
 			String value = e.getValue();
-			ColorUIResource color = parseColor( value );
-			if( color != null ) {
+			if( canParseColor( value ) ) {
 				String key = e.getKey();
-				namedColors.put( key, color );
-				defaults.put( "ColorPalette." + key, color );
+				namedColors.put( key, value );
+
+				String uiKey = "ColorPalette." + key;
+				put( properties, uiKey, value );
+
+				// this is only necessary for copyIfSetInJson() (used for accent color)
+				jsonUIKeys.add( uiKey );
 			}
 		}
 	}
@@ -380,7 +385,7 @@ public class IntelliJTheme
 	 * http://www.jetbrains.org/intellij/sdk/docs/reference_guide/ui_themes/themes_customize.html#custom-ui-control-colors
 	 */
 	@SuppressWarnings( "unchecked" )
-	private void apply( String key, Object value, UIDefaults defaults, ArrayList<Object> defaultsKeysCache, Set<String> uiKeys ) {
+	private void apply( String key, Object value, Properties properties, Set<String> jsonUIKeys ) {
 		if( value instanceof Map ) {
 			Map<String, Object> map = (Map<String, Object>)value;
 			if( map.containsKey( "os.default" ) || map.containsKey( "os.windows" ) || map.containsKey( "os.mac" ) || map.containsKey( "os.linux" ) ) {
@@ -388,12 +393,12 @@ public class IntelliJTheme
 					: SystemInfo.isMacOS ? "os.mac"
 					: SystemInfo.isLinux ? "os.linux" : null;
 				if( osKey != null && map.containsKey( osKey ) )
-					apply( key, map.get( osKey ), defaults, defaultsKeysCache, uiKeys );
+					apply( key, map.get( osKey ), properties, jsonUIKeys );
 				else if( map.containsKey( "os.default" ) )
-					apply( key, map.get( "os.default" ), defaults, defaultsKeysCache, uiKeys );
+					apply( key, map.get( "os.default" ), properties, jsonUIKeys );
 			} else {
 				for( Map.Entry<String, Object> e : map.entrySet() )
-					apply( key + '.' + e.getKey(), e.getValue(), defaults, defaultsKeysCache, uiKeys );
+					apply( key + '.' + e.getKey(), e.getValue(), properties, jsonUIKeys );
 			}
 		} else {
 			if( "".equals( value ) )
@@ -408,25 +413,40 @@ public class IntelliJTheme
 				key.equals( "Tree.rightChildIndent" ) )
 			  return; // ignore
 
+			// ignore icons
+			if( key.endsWith( "Icon" ) )
+				return; // ignore
+
 			// map keys
 			key = uiKeyMapping.getOrDefault( key, key );
 			if( key.isEmpty() )
 				return; // ignore key
 
-			// exclude properties
+			// exclude properties (1st level)
 			int dot = key.indexOf( '.' );
-			if( dot > 0 && uiKeyExcludes.contains( key.substring( 0, dot + 1 ) ) )
+			if( dot > 0 && uiKeyExcludesStartsWith.contains( key.substring( 0, dot + 1 ) ) )
 				return;
 
-			if( uiKeyDoNotOverride.contains( key ) && uiKeys.contains( key ) )
+			// exclude properties (2st level)
+			int dot2 = (dot > 0) ? key.indexOf( '.', dot + 1 ) : -1;
+			if( dot2 > 0 && uiKeyExcludesStartsWith.contains( key.substring( 0, dot2 + 1 ) ) )
 				return;
 
-			uiKeys.add( key );
+			// exclude properties (contains)
+			for( String s : uiKeyExcludesContains ) {
+				if( key.contains( s ) )
+					return;
+			}
 
-			String valueStr = value.toString();
+			if( uiKeyDoNotOverride.contains( key ) && jsonUIKeys.contains( key ) )
+				return;
+
+			jsonUIKeys.add( key );
+
+			String valueStr = value.toString().trim();
 
 			// map named colors
-			Object uiValue = namedColors.get( valueStr );
+			String uiValue = namedColors.get( valueStr );
 
 			// parse value
 			if( uiValue == null ) {
@@ -445,45 +465,62 @@ public class IntelliJTheme
 
 				// parse value
 				try {
-					uiValue = UIDefaultsLoader.parseValue( key, valueStr, null );
+					UIDefaultsLoader.parseValue( key, valueStr, null );
+					uiValue = valueStr;
 				} catch( RuntimeException ex ) {
-					UIDefaultsLoader.logParseError( key, valueStr, ex, false );
+					UIDefaultsLoader.logParseError( key, valueStr, ex, true );
 					return; // ignore invalid value
 				}
 			}
 
-			if( key.startsWith( "*." ) ) {
-				// wildcard
-				String tail = key.substring( 1 );
+			// wildcards
+			if( applyWildcard( properties, key, uiValue ) )
+				return;
 
-				// because we can not iterate over the UI defaults keys while
-				// modifying UI defaults in the same loop, we have to copy the keys
-				if( defaultsKeysCache.size() != defaults.size() ) {
-					defaultsKeysCache.clear();
-					Enumeration<Object> e = defaults.keys();
-					while( e.hasMoreElements() )
-						defaultsKeysCache.add( e.nextElement() );
+			put( properties, key, uiValue );
+		}
 	}
 
-				// replace all values in UI defaults that match the wildcard key
-				for( Object k : defaultsKeysCache ) {
-					if( k.equals( "Desktop.background" ) ||
+	private boolean applyWildcard( Properties properties, String key, String value ) {
+		if( !key.startsWith( "*." ) )
+			return false;
+
+		String tail = key.substring( 1 );
+
+		// because we can not iterate over the properties keys while
+		// modifying properties in the same loop, we have to copy the keys
+		String[] keys = properties.keySet().toArray( new String[properties.size()] );
+
+		// replace all values in properties that match the wildcard key
+		for( String k : keys ) {
+			if( k.startsWith( "*" ) ||
+				k.startsWith( "@" ) ||
+				k.startsWith( "HelpButton." ) ||
+				k.startsWith( "JX" ) ||
+				k.startsWith( "Jide" ) ||
+				k.startsWith( "ProgressBar.selection" ) ||
+				k.startsWith( "TitlePane." ) ||
+				k.startsWith( "ToggleButton.tab." ) ||
+				k.equals( "Desktop.background" ) ||
 				k.equals( "DesktopIcon.background" ) ||
-						k.equals( "TabbedPane.focusColor" ) )
+				k.equals( "TabbedPane.focusColor" ) ||
+				k.endsWith( ".hoverBackground" ) ||
+				k.endsWith( ".pressedBackground" ) )
 			  continue;
 
-					if( k instanceof String ) {
 			// support replacing of mapped keys
 			// (e.g. set ComboBox.buttonEditableBackground to *.background
 			// because it is mapped from ComboBox.ArrowButton.background)
-						String km = uiKeyInverseMapping.getOrDefault( k, (String) k );
-						if( km.endsWith( tail ) && !((String)k).startsWith( "CheckBox.icon." ) )
-							defaults.put( k, uiValue );
-					}
-				}
-			} else
-				defaults.put( key, uiValue );
+			String km = uiKeyInverseMapping.getOrDefault( k, k );
+			if( km.endsWith( tail ) && !k.startsWith( "CheckBox.icon." ) )
+				put( properties, k, value );
 		}
+
+		// Note: also add wildcards to properties and let UIDefaultsLoader
+		//       process it on BasicLookAndFeel UI defaults
+		put( properties, key, value );
+
+		return true;
 	}
 
 	private String fixColorIfValid( String newColorStr, String colorStr ) {
@@ -497,11 +534,11 @@ public class IntelliJTheme
 		}
 	}
 
-	private void applyColorPalette( UIDefaults defaults ) {
-		if( icons == null )
+	private void applyIconsColorPalette( Properties properties ) {
+		if( jsonIcons == null )
 			return;
 
-		Object palette = icons.get( "ColorPalette" );
+		Object palette = jsonIcons.get( "ColorPalette" );
 		if( !(palette instanceof Map) )
 			return;
 
@@ -510,44 +547,48 @@ public class IntelliJTheme
 		for( Map.Entry<String, Object> e : colorPalette.entrySet() ) {
 			String key = e.getKey();
 			Object value = e.getValue();
-			if( key.startsWith( "Checkbox." ) || !(value instanceof String) )
+			if( key.startsWith( "Checkbox." ) || key.startsWith( "#" ) || !(value instanceof String) )
 				continue;
 
 			if( dark )
 				key = StringUtils.removeTrailing( key, ".Dark" );
 
-			ColorUIResource color = toColor( (String) value );
+			String color = toColor( (String) value );
 			if( color != null )
-				defaults.put( key, color );
+				put( properties, key, color );
 		}
 	}
 
-	private ColorUIResource toColor( String value ) {
+	private String toColor( String value ) {
+		if( value.startsWith( "##" ) )
+			value = fixColorIfValid( value.substring( 1 ), value );
+
 		// map named colors
-		ColorUIResource color = namedColors.get( value );
+		String color = namedColors.get( value );
 
 		// parse color
-		return (color != null) ? color : parseColor( value );
+		return (color != null) ? color : (canParseColor( value ) ? value : null);
 	}
 
-	private ColorUIResource parseColor( String value ) {
+	private boolean canParseColor( String value ) {
 		try {
-			return UIDefaultsLoader.parseColor( value );
+			return UIDefaultsLoader.parseColor( value ) != null;
 		} catch( IllegalArgumentException ex ) {
-			return null;
+			LoggingFacade.INSTANCE.logSevere( "FlatLaf: Failed to parse color: '" + value + '\'', ex );
+			return false;
 		}
 	}
 
 	/**
 	 * Because IDEA uses SVGs for check boxes and radio buttons, the colors for
 	 * these two components are specified in "icons > ColorPalette".
-	 * FlatLaf uses vector icons and expects colors for the two components in UI defaults.
+	 * FlatLaf uses vector icons and expects colors for the two components in properties.
 	 */
-	private void applyCheckBoxColors( UIDefaults defaults ) {
-		if( icons == null )
+	private void applyCheckBoxColors( Properties properties ) {
+		if( jsonIcons == null )
 			return;
 
-		Object palette = icons.get( "ColorPalette" );
+		Object palette = jsonIcons.get( "ColorPalette" );
 		if( !(palette instanceof Map) )
 			return;
 
@@ -569,9 +610,9 @@ public class IntelliJTheme
 				if( !dark && newKey.startsWith( checkBoxIconPrefix ) )
 					newKey = "CheckBox.icon[filled].".concat( newKey.substring( checkBoxIconPrefix.length() ) );
 
-				ColorUIResource color = toColor( (String) value );
+				String color = toColor( (String) value );
 				if( color != null ) {
-					defaults.put( newKey, color );
+					put( properties, newKey, color );
 
 					String key2 = checkboxDuplicateColors.get( key + ".Dark");
 					if( key2 != null ) {
@@ -592,7 +633,7 @@ public class IntelliJTheme
 
 						String newKey2 = checkboxKeyMapping.get( key2 );
 						if( newKey2 != null )
-							defaults.put( newKey2, color );
+							put( properties, newKey2, color );
 					}
 				}
 
@@ -603,13 +644,13 @@ public class IntelliJTheme
 		// update hover, pressed and focused colors
 		if( checkboxModified ) {
 			// for non-filled checkbox/radiobutton used in dark themes
-			defaults.remove( "CheckBox.icon.focusWidth" );
-			defaults.put( "CheckBox.icon.hoverBorderColor", defaults.get( "CheckBox.icon.focusedBorderColor" ) );
+			properties.remove( "CheckBox.icon.focusWidth" );
+			put( properties, "CheckBox.icon.hoverBorderColor", properties.get( "CheckBox.icon.focusedBorderColor" ) );
 
 			// for filled checkbox/radiobutton used in light themes
-			defaults.remove( "CheckBox.icon[filled].focusWidth" );
-			defaults.put( "CheckBox.icon[filled].hoverBorderColor", defaults.get( "CheckBox.icon[filled].focusedBorderColor" ) );
-			defaults.put( "CheckBox.icon[filled].focusedSelectedBackground", defaults.get( "CheckBox.icon[filled].selectedBackground" ) );
+			properties.remove( "CheckBox.icon[filled].focusWidth" );
+			put( properties, "CheckBox.icon[filled].hoverBorderColor", properties.get( "CheckBox.icon[filled].focusedBorderColor" ) );
+			put( properties, "CheckBox.icon[filled].focusedSelectedBackground", properties.get( "CheckBox.icon[filled].selectedBackground" ) );
 
 			if( dark ) {
 				// IDEA Darcula checkBoxFocused.svg, checkBoxSelectedFocused.svg,
@@ -623,22 +664,16 @@ public class IntelliJTheme
 					"CheckBox.icon[filled].focusedSelectedBorderColor",
 				};
 				for( String key : focusedBorderColorKeys ) {
-					Color color = defaults.getColor( key );
-					if( color != null ) {
-						defaults.put( key, new ColorUIResource( new Color(
-							(color.getRGB() & 0xffffff) | 0xa6000000, true ) ) );
-					}
+					Object color = properties.get( key );
+					if( color != null )
+						put( properties, key, "fade(" + color + ", 65%)" );
 				}
 			}
 		}
 	}
 
-	private void copyIfNotSet( UIDefaults defaults, String destKey, String srcKey, Set<String> uiKeys ) {
-		if( !uiKeys.contains( destKey ) )
-			defaults.put( destKey, defaults.get( srcKey ) );
-	}
-
-	private static final Set<String> uiKeyExcludes;
+	private static final Set<String> uiKeyExcludesStartsWith;
+	private static final String[] uiKeyExcludesContains;
 	private static final Set<String> uiKeyDoNotOverride;
 	/** Rename UI default keys (key --> value). */
 	private static final Map<String, String> uiKeyMapping = new HashMap<>();
@@ -650,29 +685,30 @@ public class IntelliJTheme
 
 	static {
 		// IntelliJ UI properties that are not used in FlatLaf
-		uiKeyExcludes = new HashSet<>( Arrays.asList(
+		uiKeyExcludesStartsWith = new HashSet<>( Arrays.asList(
 			"ActionButton.", "ActionToolbar.", "ActionsList.", "AppInspector.", "AssignedMnemonic.", "Autocomplete.",
 			"AvailableMnemonic.",
-			"BigSpinner.", "Bookmark.", "BookmarkIcon.", "BookmarkMnemonicAssigned.", "BookmarkMnemonicAvailable.",
+			"Badge.", "Banner.", "BigSpinner.", "Bookmark.", "BookmarkIcon.", "BookmarkMnemonicAssigned.", "BookmarkMnemonicAvailable.",
 			"BookmarkMnemonicCurrent.", "BookmarkMnemonicIcon.", "Borders.", "Breakpoint.",
-			"Canvas.", "CodeWithMe.", "ComboBoxButton.", "CompletionPopup.", "ComplexPopup.", "Content.",
-			"CurrentMnemonic.", "Counter.",
-			"Debugger.", "DebuggerPopup.", "DebuggerTabs.", "DefaultTabs.", "Dialog.", "DialogWrapper.", "DragAndDrop.",
+			"Canvas.", "CellEditor.", "Code.", "CodeWithMe.", "ColumnControlButton.", "CombinedDiff.", "ComboBoxButton.",
+			"CompilationCharts.", "CompletionPopup.", "ComplexPopup.", "Content.", "ContextHelp.", "CurrentMnemonic.", "Counter.",
+			"Debugger.", "DebuggerPopup.", "DebuggerTabs.", "DefaultTabs.", "Dialog.", "DialogWrapper.",
+			"DisclosureButton.", "DragAndDrop.",
 			"Editor.", "EditorGroupsTabs.", "EditorTabs.",
-			"FileColor.", "FlameGraph.", "Focus.",
+			"FileColor.", "FindPopup.", "FlameGraph.", "Focus.",
 			"Git.", "Github.", "GotItTooltip.", "Group.", "Gutter.", "GutterTooltip.",
 			"HeaderColor.", "HelpTooltip.", "Hg.",
-			"IconBadge.", "InformationHint.", "InplaceRefactoringPopup.",
-			"Lesson.", "Link.", "LiveIndicator.",
-			"MainMenu.", "MainToolbar.", "MemoryIndicator.", "MlModelBinding.", "MnemonicIcon.",
+			"IconBadge.", "InformationHint.", "InlineBanner.", "InplaceRefactoringPopup.",
+			"Lesson.", "LineProfiler.", "Link.", "LiveIndicator.",
+			"MainMenu.", "MainToolbar.", "MainWindow.", "MemoryIndicator.", "MlModelBinding.", "MnemonicIcon.",
 			"NavBar.", "NewClass.", "NewPSD.", "Notification.", "Notifications.", "NotificationsToolwindow.",
 			"OnePixelDivider.", "OptionButton.", "Outline.",
-			"ParameterInfo.", "Plugins.", "ProgressIcon.", "PsiViewer.",
-			"ReviewList.", "RunWidget.",
+			"ParameterInfo.", "PresentationAssistant.", "Plugins.", "Profiler.", "ProgressIcon.", "PsiViewer.",
+			"Resizable.", "Review.", "ReviewList.", "RunToolbar.", "RunWidget.",
 			"ScreenView.", "SearchEverywhere.", "SearchFieldWithExtension.", "SearchMatch.", "SearchOption.",
 			"SearchResults.", "SegmentedButton.", "Settings.", "SidePanel.", "Space.", "SpeedSearch.", "StateWidget.",
-			"StatusBar.",
-			"Tag.", "TipOfTheDay.", "ToolbarComboWidget.", "ToolWindow.",
+			"StatusBar.", "StripeToolbar.",
+			"Tag.", "TipOfTheDay.", "ToolbarComboWidget.", "ToolWindow.", "TrialWidget.",
 			"UIDesigner.", "UnattendedHostStatus.",
 			"ValidationTooltip.", "VersionControl.",
 			"WelcomeScreen.",
@@ -683,11 +719,24 @@ public class IntelliJTheme
 			// possible typos in .theme.json files
 			"Checkbox.", "Toolbar.", "Tooltip.", "UiDesigner.", "link."
 		) );
+		uiKeyExcludesContains = new String[] {
+			".darcula."
+		};
 
 		uiKeyDoNotOverride = new HashSet<>( Arrays.asList(
 			"TabbedPane.selectedForeground"
 		) );
 
+		// "*."
+		uiKeyMapping.put( "*.fontFace", "" ); // ignore (used in OnePauintxi themes)
+		uiKeyMapping.put( "*.fontSize", "" ); // ignore (used in OnePauintxi themes)
+
+		// Button
+		uiKeyMapping.put( "Button.minimumSize", "" ); // ignore (used in Material Theme UI Lite)
+
+		// CheckBox.iconSize
+		uiKeyMapping.put( "CheckBox.iconSize", "" ); // ignore (used in Rider themes)
+
 		// ComboBox
 		uiKeyMapping.put( "ComboBox.background",                        "" ); // ignore
 		uiKeyMapping.put( "ComboBox.buttonBackground",                  "" ); // ignore
@@ -696,14 +745,17 @@ public class IntelliJTheme
 		uiKeyMapping.put( "ComboBox.ArrowButton.disabledIconColor",     "ComboBox.buttonDisabledArrowColor" );
 		uiKeyMapping.put( "ComboBox.ArrowButton.iconColor",             "ComboBox.buttonArrowColor" );
 		uiKeyMapping.put( "ComboBox.ArrowButton.nonEditableBackground", "ComboBox.buttonBackground" );
-		uiKeyCopying.put( "ComboBox.buttonSeparatorColor",              "Component.borderColor" );
-		uiKeyCopying.put( "ComboBox.buttonDisabledSeparatorColor",      "Component.disabledBorderColor" );
 
 		// Component
 		uiKeyMapping.put( "Component.inactiveErrorFocusColor",   "Component.error.borderColor" );
 		uiKeyMapping.put( "Component.errorFocusColor",           "Component.error.focusedBorderColor" );
 		uiKeyMapping.put( "Component.inactiveWarningFocusColor", "Component.warning.borderColor" );
 		uiKeyMapping.put( "Component.warningFocusColor",         "Component.warning.focusedBorderColor" );
+		uiKeyMapping.put( "Component.inactiveSuccessFocusColor", "Component.success.borderColor" );
+		uiKeyMapping.put( "Component.successFocusColor",         "Component.success.focusedBorderColor" );
+
+		// Label
+		uiKeyMapping.put( "Label.disabledForegroundColor", "" ); // ignore (used in Material Theme UI Lite)
 
 		// Link
 		uiKeyMapping.put( "Link.activeForeground", "Component.linkColor" );
@@ -711,10 +763,7 @@ public class IntelliJTheme
 		// Menu
 		uiKeyMapping.put( "Menu.border",                "Menu.margin" );
 		uiKeyMapping.put( "MenuItem.border",            "MenuItem.margin" );
-		uiKeyCopying.put( "CheckBoxMenuItem.margin",    "MenuItem.margin" );
-		uiKeyCopying.put( "RadioButtonMenuItem.margin", "MenuItem.margin" );
 		uiKeyMapping.put( "PopupMenu.border",           "PopupMenu.borderInsets" );
-		uiKeyCopying.put( "MenuItem.underlineSelectionColor", "TabbedPane.underlineColor" );
 
 		// IDEA uses List.selectionBackground also for menu selection
 		uiKeyCopying.put( "Menu.selectionBackground",                "List.selectionBackground" );
@@ -722,13 +771,14 @@ public class IntelliJTheme
 		uiKeyCopying.put( "CheckBoxMenuItem.selectionBackground",    "List.selectionBackground" );
 		uiKeyCopying.put( "RadioButtonMenuItem.selectionBackground", "List.selectionBackground" );
 
-		// ProgressBar
+		// ProgressBar: IDEA uses ProgressBar.trackColor and ProgressBar.progressColor
 		uiKeyMapping.put( "ProgressBar.background",    "" ); // ignore
 		uiKeyMapping.put( "ProgressBar.foreground",    "" ); // ignore
 		uiKeyMapping.put( "ProgressBar.trackColor",    "ProgressBar.background" );
 		uiKeyMapping.put( "ProgressBar.progressColor", "ProgressBar.foreground" );
-		uiKeyCopying.put( "ProgressBar.selectionForeground", "ProgressBar.background" );
-		uiKeyCopying.put( "ProgressBar.selectionBackground", "ProgressBar.foreground" );
+
+		// RadioButton
+		uiKeyMapping.put( "RadioButton.iconSize", "" ); // ignore (used in Rider themes)
 
 		// ScrollBar
 		uiKeyMapping.put( "ScrollBar.trackColor", "ScrollBar.track" );
@@ -738,34 +788,30 @@ public class IntelliJTheme
 		uiKeyMapping.put( "Separator.separatorColor", "Separator.foreground" );
 
 		// Slider
+		uiKeyMapping.put( "Slider.buttonColor", "Slider.thumbColor" );
+		uiKeyMapping.put( "Slider.buttonBorderColor", "" ); // ignore
+		uiKeyMapping.put( "Slider.thumb", "" ); // ignore (used in Material Theme UI Lite)
+		uiKeyMapping.put( "Slider.track", "" ); // ignore (used in Material Theme UI Lite)
+		uiKeyMapping.put( "Slider.trackDisabled", "" ); // ignore (used in Material Theme UI Lite)
 		uiKeyMapping.put( "Slider.trackWidth", "" ); // ignore (used in Material Theme UI Lite)
-		uiKeyCopying.put( "Slider.trackValueColor", "ProgressBar.foreground" );
-		uiKeyCopying.put( "Slider.thumbColor", "ProgressBar.foreground" );
-		uiKeyCopying.put( "Slider.trackColor", "ProgressBar.background" );
-
-		// Spinner
-		uiKeyCopying.put( "Spinner.buttonSeparatorColor",         "Component.borderColor" );
-		uiKeyCopying.put( "Spinner.buttonDisabledSeparatorColor", "Component.disabledBorderColor" );
 
 		// TabbedPane
 		uiKeyMapping.put( "DefaultTabs.underlinedTabBackground", "TabbedPane.selectedBackground" );
 		uiKeyMapping.put( "DefaultTabs.underlinedTabForeground", "TabbedPane.selectedForeground" );
 		uiKeyMapping.put( "DefaultTabs.inactiveUnderlineColor",  "TabbedPane.inactiveUnderlineColor" );
+		uiKeyMapping.put( "TabbedPane.tabAreaInsets", "" ); // ignore (used in Material Theme UI Lite)
+
+		// TableHeader
+		uiKeyMapping.put( "TableHeader.cellBorder", "" ); // ignore (used in Material Theme UI Lite)
+		uiKeyMapping.put( "TableHeader.height", "" ); // ignore (used in Material Theme UI Lite)
 
 		// TitlePane
-		uiKeyCopying.put( "TitlePane.inactiveBackground",     "TitlePane.background" );
 		uiKeyMapping.put( "TitlePane.infoForeground",         "TitlePane.foreground" );
 		uiKeyMapping.put( "TitlePane.inactiveInfoForeground", "TitlePane.inactiveForeground" );
 
 		for( Map.Entry<String, String> e : uiKeyMapping.entrySet() )
 			uiKeyInverseMapping.put( e.getValue(), e.getKey() );
 
-		uiKeyCopying.put( "ToggleButton.tab.underlineColor",         "TabbedPane.underlineColor" );
-		uiKeyCopying.put( "ToggleButton.tab.disabledUnderlineColor", "TabbedPane.disabledUnderlineColor" );
-		uiKeyCopying.put( "ToggleButton.tab.selectedBackground",     "TabbedPane.selectedBackground" );
-		uiKeyCopying.put( "ToggleButton.tab.hoverBackground",        "TabbedPane.hoverColor" );
-		uiKeyCopying.put( "ToggleButton.tab.focusBackground",        "TabbedPane.focusColor" );
-
 		checkboxKeyMapping.put( "Checkbox.Background.Default",  "CheckBox.icon.background" );
 		checkboxKeyMapping.put( "Checkbox.Background.Disabled", "CheckBox.icon.disabledBackground" );
 		checkboxKeyMapping.put( "Checkbox.Border.Default",      "CheckBox.icon.borderColor" );
@@ -818,17 +864,15 @@ public class IntelliJTheme
 		}
 
 		@Override
-		void applyAdditionalDefaults( UIDefaults defaults ) {
-			theme.applyProperties( defaults );
+		void applyAdditionalProperties( Properties properties ) {
+			theme.applyProperties( properties );
 		}
 
 		@Override
 		protected ArrayList<Class<?>> getLafClassesForDefaultsLoading() {
-			ArrayList<Class<?>> lafClasses = new ArrayList<>();
-			lafClasses.add( FlatLaf.class );
-			lafClasses.add( theme.dark ? FlatDarkLaf.class : FlatLightLaf.class );
-			lafClasses.add( theme.dark ? FlatDarculaLaf.class : FlatIntelliJLaf.class );
-			lafClasses.add( ThemeLaf.class );
+			ArrayList<Class<?>> lafClasses = UIDefaultsLoader.getLafClassesForDefaultsLoading( getClass() );
+			lafClasses.add( 1, theme.dark ? FlatDarkLaf.class : FlatLightLaf.class );
+			lafClasses.add( 2, theme.dark ? FlatDarculaLaf.class : FlatIntelliJLaf.class );
 			return lafClasses;
 		}
 	}

flatlaf-core/src/main/java/com/formdev/flatlaf/LinuxFontPolicy.java

@@ -111,7 +111,7 @@ class LinuxFontPolicy
 		if( logicalFamily != null )
 			family = logicalFamily;
 
-		return createFontEx( family, style, size, dsize );
+		return createFontEx( family, style, size );
 	}
 
 	/**
@@ -121,9 +121,9 @@ class LinuxFontPolicy
 	 * E.g. family 'URW Bookman Light' is not found, but 'URW Bookman' is found.
 	 * If still not found, then font of family 'Dialog' is returned.
 	 */
-	private static Font createFontEx( String family, int style, int size, double dsize ) {
+	private static Font createFontEx( String family, int style, int size ) {
 		for(;;) {
-			Font font = createFont( family, style, size, dsize );
+			Font font = FlatLaf.createCompositeFont( family, style, size );
 
 			if( Font.DIALOG.equals( family ) )
 				return font;
@@ -135,7 +135,7 @@ class LinuxFontPolicy
 				// - character width is zero (e.g. font Cantarell; Fedora; Oracle Java 8)
 				FontMetrics fm = StyleContext.getDefaultStyleContext().getFontMetrics( font );
 				if( fm.getHeight() > size * 2 || fm.stringWidth( "a" ) == 0 )
-					return createFont( Font.DIALOG, style, size, dsize );
+					return FlatLaf.createCompositeFont( Font.DIALOG, style, size );
 
 				return font;
 			}
@@ -143,7 +143,7 @@ class LinuxFontPolicy
 			// find last word in family
 			int index = family.lastIndexOf( ' ' );
 			if( index < 0 )
-				return createFont( Font.DIALOG, style, size, dsize );
+				return FlatLaf.createCompositeFont( Font.DIALOG, style, size );
 
 			// check whether last work contains some font weight (e.g. Ultra-Bold or Heavy)
 			String lastWord = family.substring( index + 1 ).toLowerCase( Locale.ENGLISH );
@@ -155,15 +155,6 @@ class LinuxFontPolicy
 		}
 	}
 
-	private static Font createFont( String family, int style, int size, double dsize ) {
-		Font font = FlatLaf.createCompositeFont( family, style, size );
-
-		// set font size in floating points
-		font = font.deriveFont( style, (float) dsize );
-
-		return font;
-	}
-
 	private static double getGnomeFontScale() {
 		// do not scale font here if JRE scales
 		if( isSystemScaling() )
@@ -203,7 +194,7 @@ class LinuxFontPolicy
 	 * Gets the default font for KDE from KDE configuration files.
 	 *
 	 * The Swing fonts are not updated when the user changes system font size
-	 * (System Settings > Fonts > Force Font DPI). A application restart is necessary.
+	 * (System Settings > Fonts > Force Font DPI). An application restart is necessary.
 	 * This is the same behavior as in native KDE applications.
 	 *
 	 * The "display scale factor" (kdeglobals: [KScreen] > ScaleFactor) is not used
@@ -257,7 +248,7 @@ class LinuxFontPolicy
 		if( size < 1 )
 			size = 1;
 
-		return createFont( family, style, size, dsize );
+		return FlatLaf.createCompositeFont( family, style, size );
 	}
 
 	@SuppressWarnings( "MixedMutabilityReturnType" ) // Error Prone

flatlaf-core/src/main/java/com/formdev/flatlaf/LinuxPopupMenuCanceler.java

@@ -0,0 +1,166 @@
+/*
+ * Copyright 2025 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf;
+
+import java.awt.Component;
+import java.awt.Window;
+import java.awt.event.ComponentEvent;
+import java.awt.event.ComponentListener;
+import java.awt.event.WindowAdapter;
+import java.awt.event.WindowEvent;
+import javax.swing.JPopupMenu;
+import javax.swing.MenuElement;
+import javax.swing.MenuSelectionManager;
+import javax.swing.SwingUtilities;
+import javax.swing.event.ChangeEvent;
+import javax.swing.event.ChangeListener;
+
+/**
+ * Cancels (hides) popup menus on Linux.
+ * <p>
+ * On Linux, popups are not hidden under following conditions, which results in
+ * misplaced popups:
+ * <ul>
+ *   <li>window moved or resized
+ *   <li>window maximized or restored
+ *   <li>window iconified
+ *   <li>window deactivated (e.g. activated other application)
+ * </ul>
+ *
+ * On Windows and macOS, popups are automatically hidden.
+ * <p>
+ * The implementation is similar to what's done in
+ * {@code javax.swing.plaf.basic.BasicPopupMenuUI.MouseGrabber},
+ * but only hides popup in some conditions.
+ *
+ * @author Karl Tauber
+ */
+class LinuxPopupMenuCanceler
+	extends WindowAdapter
+	implements ChangeListener, ComponentListener
+{
+	private MenuElement[] lastPathSelectedPath;
+	private Window window;
+
+	LinuxPopupMenuCanceler() {
+		MenuSelectionManager msm = MenuSelectionManager.defaultManager();
+		msm.addChangeListener( this );
+
+		lastPathSelectedPath = msm.getSelectedPath();
+		if( lastPathSelectedPath.length > 0 )
+			addWindowListeners( lastPathSelectedPath[0] );
+	}
+
+	void uninstall() {
+		MenuSelectionManager.defaultManager().removeChangeListener( this );
+	}
+
+	private void addWindowListeners( MenuElement selected ) {
+		removeWindowListeners();
+
+		// see BasicPopupMenuUI.MouseGrabber.grabWindow()
+		Component invoker = selected.getComponent();
+		if( invoker instanceof JPopupMenu )
+			invoker = ((JPopupMenu)invoker).getInvoker();
+		window = (invoker instanceof Window)
+			? (Window) invoker
+			: SwingUtilities.windowForComponent( invoker );
+
+		if( window != null ) {
+			window.addWindowListener( this );
+			window.addComponentListener( this );
+		}
+	}
+
+	private void removeWindowListeners() {
+		if( window != null ) {
+			window.removeWindowListener( this );
+			window.removeComponentListener( this );
+			window = null;
+		}
+	}
+
+	private void cancelPopupMenu() {
+		try {
+			MenuSelectionManager msm = MenuSelectionManager.defaultManager();
+			MenuElement[] selectedPath = msm.getSelectedPath();
+			for( MenuElement e : selectedPath ) {
+				if( e instanceof JPopupMenu )
+					((JPopupMenu)e).putClientProperty( "JPopupMenu.firePopupMenuCanceled", true );
+			}
+			msm.clearSelectedPath();
+		} catch( RuntimeException ex ) {
+			removeWindowListeners();
+			throw ex;
+		} catch( Error ex ) {
+			removeWindowListeners();
+			throw ex;
+		}
+	}
+
+	//---- ChangeListener ----
+
+	@Override
+	public void stateChanged( ChangeEvent e ) {
+		MenuElement[] selectedPath = MenuSelectionManager.defaultManager().getSelectedPath();
+
+		if( selectedPath.length == 0 )
+			removeWindowListeners();
+		else if( lastPathSelectedPath.length == 0 )
+			addWindowListeners( selectedPath[0] );
+
+		lastPathSelectedPath = selectedPath;
+	}
+
+	//---- WindowListener ----
+
+	@Override
+	public void windowIconified( WindowEvent e ) {
+		cancelPopupMenu();
+	}
+
+	@Override
+	public void windowDeactivated( WindowEvent e ) {
+		cancelPopupMenu();
+	}
+
+	@Override
+	public void windowClosing( WindowEvent e ) {
+		cancelPopupMenu();
+	}
+
+	//---- ComponentListener ----
+
+	@Override
+	public void componentResized( ComponentEvent e ) {
+		cancelPopupMenu();
+	}
+
+	@Override
+	public void componentMoved( ComponentEvent e ) {
+		cancelPopupMenu();
+	}
+
+	@Override
+	public void componentShown( ComponentEvent e ) {
+	}
+
+	@Override
+	public void componentHidden( ComponentEvent e ) {
+		cancelPopupMenu();
+	}
+}

flatlaf-core/src/main/java/com/formdev/flatlaf/SubMenuUsabilityHelper.java

@@ -45,6 +45,7 @@ import javax.swing.UIManager;
 import javax.swing.event.ChangeEvent;
 import javax.swing.event.ChangeListener;
 import com.formdev.flatlaf.ui.FlatUIUtils;
+import com.formdev.flatlaf.util.LoggingFacade;
 
 /**
  * Improves usability of submenus by using a
@@ -64,6 +65,7 @@ class SubMenuUsabilityHelper
 	// https://github.com/apache/netbeans/issues/4231#issuecomment-1179616607
 	private static SubMenuUsabilityHelper instance;
 
+	private boolean eventQueuePushNotSupported;
 	private SubMenuEventQueue subMenuEventQueue;
 	private SafeTrianglePainter safeTrianglePainter;
 	private boolean changePending;
@@ -83,6 +85,9 @@ class SubMenuUsabilityHelper
 		if( instance != null )
 			return false;
 
+		if( !FlatSystemProperties.getBoolean( FlatSystemProperties.USE_SUB_MENU_SAFE_TRIANGLE, true ) )
+			return false;
+
 		instance = new SubMenuUsabilityHelper();
 		MenuSelectionManager.defaultManager().addChangeListener( instance );
 		return true;
@@ -99,7 +104,7 @@ class SubMenuUsabilityHelper
 
 	@Override
 	public void stateChanged( ChangeEvent e ) {
-		if( !FlatUIUtils.getUIBoolean( KEY_USE_SAFE_TRIANGLE, true ))
+		if( eventQueuePushNotSupported || !FlatUIUtils.getUIBoolean( KEY_USE_SAFE_TRIANGLE, true ))
 			return;
 
 		// handle menu selection change later, but only once in case of temporary changes
@@ -172,9 +177,30 @@ debug*/
 		targetTopY = popupLocation.y;
 		targetBottomY = popupLocation.y + popupSize.height;
 
-		// install own event queue to supress mouse events when mouse is moved within safe triangle
-		if( subMenuEventQueue == null )
-			subMenuEventQueue = new SubMenuEventQueue();
+		// install own event queue to suppress mouse events when mouse is moved within safe triangle
+		if( subMenuEventQueue == null ) {
+			SubMenuEventQueue queue = new SubMenuEventQueue();
+
+			try {
+				Toolkit toolkit = Toolkit.getDefaultToolkit();
+				toolkit.getSystemEventQueue().push( queue );
+
+				// check whether push() worked
+				// (e.g. SWTSwing uses own event queue that does not support push())
+				if( toolkit.getSystemEventQueue() != queue ) {
+					eventQueuePushNotSupported = true;
+					LoggingFacade.INSTANCE.logSevere( "FlatLaf: Failed to push submenu event queue. Disabling submenu safe triangle.", null );
+					return;
+				}
+
+				subMenuEventQueue = queue;
+			} catch( RuntimeException ex ) {
+				// catch runtime exception from EventQueue.push()
+				eventQueuePushNotSupported = true;
+				LoggingFacade.INSTANCE.logSevere( "FlatLaf: Failed to push submenu event queue. Disabling submenu safe triangle.", ex );
+				return;
+			}
+		}
 
 		// create safe triangle painter
 		if( safeTrianglePainter == null && UIManager.getBoolean( KEY_SHOW_SAFE_TRIANGLE ) )
@@ -247,8 +273,6 @@ debug*/
 				}
 			} );
 			timeoutTimer.setRepeats( false );
-
-			Toolkit.getDefaultToolkit().getSystemEventQueue().push( this );
 		}
 
 		void uninstall() {

flatlaf-core/src/main/java/com/formdev/flatlaf/UIDefaultsLoader.java

@@ -25,12 +25,15 @@ import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
 import java.io.StreamTokenizer;
 import java.io.StringReader;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Executable;
 import java.lang.reflect.Method;
 import java.net.URL;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -41,6 +44,8 @@ import java.util.Locale;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Properties;
+import java.util.Set;
+import java.util.function.Consumer;
 import java.util.function.Function;
 import javax.swing.Icon;
 import javax.swing.UIDefaults;
@@ -61,7 +66,6 @@ import com.formdev.flatlaf.util.HSLColor;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.SoftCache;
 import com.formdev.flatlaf.util.StringUtils;
-import com.formdev.flatlaf.util.SystemInfo;
 import com.formdev.flatlaf.util.UIScale;
 
 /**
@@ -85,15 +89,14 @@ class UIDefaultsLoader
 	private static final String WILDCARD_PREFIX = "*.";
 
 	static final String KEY_VARIABLES = "FlatLaf.internal.variables";
+	static final String KEY_PROPERTIES = "FlatLaf.internal.properties";
 
 	private static int parseColorDepth;
 
 	private static Map<String, ColorUIResource> systemColorCache;
 	private static final SoftCache<String, Object> fontCache = new SoftCache<>();
 
-	static void loadDefaultsFromProperties( Class<?> lookAndFeelClass, List<FlatDefaultsAddon> addons,
-		Properties additionalDefaults, boolean dark, UIDefaults defaults )
-	{
+	static ArrayList<Class<?>> getLafClassesForDefaultsLoading( Class<?> lookAndFeelClass ) {
 		// determine classes in class hierarchy in reverse order
 		ArrayList<Class<?>> lafClasses = new ArrayList<>();
 		for( Class<?> lafClass = lookAndFeelClass;
@@ -102,20 +105,62 @@ class UIDefaultsLoader
 		{
 			lafClasses.add( 0, lafClass );
 		}
+		return lafClasses;
+	}
 
-		loadDefaultsFromProperties( lafClasses, addons, additionalDefaults, dark, defaults );
+	static Properties newUIProperties( boolean dark ) {
+		// UI key prefixes
+		String lightOrDarkPrefix = FlatLaf.getUIKeyLightOrDarkPrefix( dark );
+		Set<String> platformPrefixes = FlatLaf.getUIKeyPlatformPrefixes();
+		Set<String> specialPrefixes = FlatLaf.getUIKeySpecialPrefixes();
+
+		return new Properties() {
+			@Override
+			public void load( InputStream in ) throws IOException {
+				// use UTF-8 to load properties file
+				try( Reader reader = new InputStreamReader( in, StandardCharsets.UTF_8 )) {
+					super.load( reader );
+				}
+			}
+
+			@Override
+			public synchronized Object put( Object k, Object value ) {
+				// process key prefixes (while loading properties files)
+				String key = (String) k;
+				while( key.startsWith( "[" ) ) {
+					int closeIndex = key.indexOf( ']' );
+					if( closeIndex < 0 )
+						return null; // ignore property with invalid prefix
+
+					String prefix = key.substring( 0, closeIndex + 1 );
+
+					if( specialPrefixes.contains( prefix ) )
+						break; // keep special prefix
+
+					if( !lightOrDarkPrefix.equals( prefix ) && !platformPrefixes.contains( prefix ) )
+						return null; // ignore property
+
+					// prefix is known and enabled --> remove prefix
+					key = key.substring( closeIndex + 1 );
+				}
+
+				return super.put( key, value );
+			}
+		};
 	}
 
 	static void loadDefaultsFromProperties( List<Class<?>> lafClasses, List<FlatDefaultsAddon> addons,
-		Properties additionalDefaults, boolean dark, UIDefaults defaults )
+		Consumer<Properties> intellijThemesHook, Properties additionalDefaults, boolean dark, UIDefaults defaults )
 	{
 		try {
 			// temporary cache system colors while loading defaults,
 			// which avoids that system color getter is invoked multiple times
 			systemColorCache = (FlatLaf.getSystemColorGetter() != null) ? new HashMap<>() : null;
 
+			// all properties files will be loaded into this map
+			Properties properties = newUIProperties( dark );
+
 			// load core properties files
-			Properties properties = new Properties();
 			for( Class<?> lafClass : lafClasses ) {
 				String propertiesName = '/' + lafClass.getName().replace( '.', '/' ) + ".properties";
 				try( InputStream in = lafClass.getResourceAsStream( propertiesName ) ) {
@@ -142,6 +187,10 @@ class UIDefaultsLoader
 					addonClassLoaders.add( addonClassLoader );
 			}
 
+			// apply IntelliJ themes properties
+			if( intellijThemesHook != null )
+				intellijThemesHook.accept( properties );
+
 			// load custom properties files (usually provided by applications)
 			List<Object> customDefaultsSources = FlatLaf.getCustomDefaultsSources();
 			int size = (customDefaultsSources != null) ? customDefaultsSources.size() : 0;
@@ -160,18 +209,48 @@ class UIDefaultsLoader
 					if( classLoader == null )
 						classLoader = FlatLaf.class.getClassLoader();
 
+					boolean found = false;
 					for( Class<?> lafClass : lafClasses ) {
-						String propertiesName = packageName + '/' + lafClass.getSimpleName() + ".properties";
+						String propertiesName = packageName + '/' + simpleClassName( lafClass ) + ".properties";
 						try( InputStream in = classLoader.getResourceAsStream( propertiesName ) ) {
-							if( in != null )
+							if( in != null ) {
 								properties.load( in );
+								found = true;
+							}
+						}
+					}
+
+					// fallback for named Java modules
+					if( !found ) {
+						// Get package URL using ClassLoader.getResource(...) because this works
+						// also in named Java modules, even without opening the package in module-info.java.
+						// This extra step is necessary because ClassLoader.getResource("<package>/<file>.properties")
+						// does not work for named Java modules.
+						URL url = classLoader.getResource( packageName );
+						if( url == null )
+							continue;
+
+						String packageUrl = url.toExternalForm();
+						if( !packageUrl.endsWith( "/" ) )
+							packageUrl = packageUrl.concat( "/" );
+
+						for( Class<?> lafClass : lafClasses ) {
+							URL propertiesUrl = new URL( packageUrl + simpleClassName( lafClass ) + ".properties" );
+
+							try( InputStream in = propertiesUrl.openStream() ) {
+								properties.load( in );
+							} catch( FileNotFoundException ex ) {
+								// ignore
+							}
 						}
 					}
 				} else if( source instanceof URL ) {
 					// load from package URL
-					URL packageUrl = (URL) source;
+					String packageUrl = ((URL)source).toExternalForm();
+					if( !packageUrl.endsWith( "/" ) )
+						packageUrl = packageUrl.concat( "/" );
 					for( Class<?> lafClass : lafClasses ) {
-						URL propertiesUrl = new URL( packageUrl + lafClass.getSimpleName() + ".properties" );
+						URL propertiesUrl = new URL( packageUrl + simpleClassName( lafClass ) + ".properties" );
 
 						try( InputStream in = propertiesUrl.openStream() ) {
 							properties.load( in );
@@ -183,7 +262,7 @@ class UIDefaultsLoader
 					// load from folder
 					File folder = (File) source;
 					for( Class<?> lafClass : lafClasses ) {
-						File propertiesFile = new File( folder, lafClass.getSimpleName() + ".properties" );
+						File propertiesFile = new File( folder, simpleClassName( lafClass ) + ".properties" );
 						if( !propertiesFile.isFile() )
 							continue;
 
@@ -198,41 +277,6 @@ class UIDefaultsLoader
 			if( additionalDefaults != null )
 				properties.putAll( additionalDefaults );
 
-			// collect all platform specific keys (but do not modify properties)
-			ArrayList<String> platformSpecificKeys = new ArrayList<>();
-			for( Object okey : properties.keySet() ) {
-				String key = (String) okey;
-				if( key.startsWith( "[" ) &&
-					(key.startsWith( "[win]" ) ||
-					 key.startsWith( "[mac]" ) ||
-					 key.startsWith( "[linux]" ) ||
-					 key.startsWith( "[light]" ) ||
-					 key.startsWith( "[dark]" )) )
-				  platformSpecificKeys.add( key );
-			}
-
-			// remove platform specific properties and re-add only properties
-			// for current platform, but with platform prefix removed
-			if( !platformSpecificKeys.isEmpty() ) {
-				// handle light/dark specific properties
-				String lightOrDarkPrefix = dark ? "[dark]" : "[light]";
-				for( String key : platformSpecificKeys ) {
-					if( key.startsWith( lightOrDarkPrefix ) )
-						properties.put( key.substring( lightOrDarkPrefix.length() ), properties.remove( key ) );
-				}
-
-				// handle platform specific properties
-				String platformPrefix =
-					SystemInfo.isWindows ? "[win]" :
-					SystemInfo.isMacOS ? "[mac]" :
-					SystemInfo.isLinux ? "[linux]" : "[unknown]";
-				for( String key : platformSpecificKeys ) {
-					Object value = properties.remove( key );
-					if( key.startsWith( platformPrefix ) )
-						properties.put( key.substring( platformPrefix.length() ), value );
-				}
-			}
-
 			// get (and remove) wildcard replacements, which override all other defaults that end with same suffix
 			HashMap<String, String> wildcards = new HashMap<>();
 			Iterator<Entry<Object, Object>> it = properties.entrySet().iterator();
@@ -287,6 +331,15 @@ class UIDefaultsLoader
 			// remember variables in defaults to allow using them in styles
 			defaults.put( KEY_VARIABLES, variables );
 
+			// remember properties (for testing)
+			if( FlatSystemProperties.getBoolean( KEY_PROPERTIES, false ) ) {
+				Properties properties2 = new Properties();
+				properties2.putAll( properties );
+				for( Map.Entry<String, String> e : wildcards.entrySet() )
+					properties2.put( WILDCARD_PREFIX + e.getKey(), e.getValue() );
+				defaults.put( KEY_PROPERTIES, properties2 );
+			}
+
 			// clear/disable system color cache
 			systemColorCache = null;
 		} catch( IOException ex ) {
@@ -294,6 +347,14 @@ class UIDefaultsLoader
 		}
 	}
 
+	/**
+	 * Similar to Class.getSimpleName(), but includes enclosing class for nested classes.
+	 */
+	static String simpleClassName( Class<?> cls ) {
+		String className = cls.getName();
+		return className.substring( className.lastIndexOf( '.' ) + 1 );
+	}
+
 	static void logParseError( String key, String value, RuntimeException ex, boolean severe ) {
 		String message = "FlatLaf: Failed to parse: '" + key + '=' + value + '\'';
 		if( severe )
@@ -629,18 +690,26 @@ class UIDefaultsLoader
 		if( value.indexOf( ',' ) >= 0 ) {
 			// Syntax: top,left,bottom,right[,lineColor[,lineThickness[,arc]]]
 			List<String> parts = splitFunctionParams( value, ',' );
+			try {
 				Insets insets = parseInsets( value );
-			ColorUIResource lineColor = (parts.size() >= 5)
+				ColorUIResource lineColor = (parts.size() >= 5 && !parts.get( 4 ).isEmpty())
 					? (ColorUIResource) parseColorOrFunction( resolver.apply( parts.get( 4 ) ), resolver )
 					: null;
-			float lineThickness = (parts.size() >= 6 && !parts.get( 5 ).isEmpty()) ? parseFloat( parts.get( 5 ) ) : 1f;
-			int arc = (parts.size() >= 7) ? parseInteger( parts.get( 6 ) ) : 0;
+				float lineThickness = (parts.size() >= 6 && !parts.get( 5 ).isEmpty())
+					? parseFloat( parts.get( 5 ) )
+					: 1f;
+				int arc = (parts.size() >= 7) && !parts.get( 6 ).isEmpty()
+					? parseInteger( parts.get( 6 ) )
+					: -1;
 
 				return (LazyValue) t -> {
-				return (lineColor != null)
+					return (lineColor != null || arc > 0)
 						? new FlatLineBorder( insets, lineColor, lineThickness, arc )
 						: new FlatEmptyBorder( insets );
 				};
+			} catch( RuntimeException ex ) {
+				throw new IllegalArgumentException( "invalid border '" + value + "' (" + ex.getMessage() + ")" );
+			}
 		} else
 			return parseInstance( value, resolver, addonClassLoaders );
 	}
@@ -711,7 +780,7 @@ class UIDefaultsLoader
 				Integer.parseInt( numbers.get( 1 ) ),
 				Integer.parseInt( numbers.get( 2 ) ),
 				Integer.parseInt( numbers.get( 3 ) ) );
-		} catch( NumberFormatException ex ) {
+		} catch( NumberFormatException | IndexOutOfBoundsException ex ) {
 			throw new IllegalArgumentException( "invalid insets '" + value + "'" );
 		}
 	}
@@ -724,7 +793,7 @@ class UIDefaultsLoader
 			return new DimensionUIResource(
 				Integer.parseInt( numbers.get( 0 ) ),
 				Integer.parseInt( numbers.get( 1 ) ) );
-		} catch( NumberFormatException ex ) {
+		} catch( NumberFormatException | IndexOutOfBoundsException ex ) {
 			throw new IllegalArgumentException( "invalid size '" + value + "'" );
 		}
 	}
@@ -818,6 +887,7 @@ class UIDefaultsLoader
 		try {
 			switch( function ) {
 				case "if":			return parseColorIf( value, params, resolver );
+				case "lazy":		return parseColorLazy( value, params, resolver );
 				case "systemColor":	return parseColorSystemColor( value, params, resolver );
 				case "rgb":			return parseColorRgbOrRgba( false, params, resolver );
 				case "rgba":		return parseColorRgbOrRgba( true, params, resolver );
@@ -865,6 +935,32 @@ class UIDefaultsLoader
 		return parseColorOrFunction( resolver.apply( ifValue ), resolver );
 	}
 
+	/**
+	 * Syntax: lazy(uiKey)
+	 * <p>
+	 * This "lazy" function is only used if the "lazy" is passed as parameter to another
+	 * color function. Otherwise, the general "lazy" function is used.
+	 * <p>
+	 * Note: The color is resolved immediately, not lazy, because it is passed as parameter to another color function.
+	 * So e.g. {@code darken(lazy(List.background), 10%)} is the same as {@code darken($List.background, 10%)}.
+	 * <p>
+	 * Only useful if a property is defined as lazy and that property is used
+	 * in another property's color function. E.g.
+	 *
+	 * <pre>{@code
+	 * someProperty = lazy(List.background)
+	 * anotherProperty = darken($someProperty, 10%)
+	 * }</pre>
+	 */
+	private static Object parseColorLazy( String value, List<String> params, Function<String, String> resolver )
+		throws IllegalArgumentException
+	{
+		if( params.size() != 1 )
+			throw newMissingParametersException( value );
+
+		return parseColorOrFunction( resolver.apply( PROPERTY_PREFIX + params.get( 0 ) ), resolver );
+	}
+
 	/**
 	 * Syntax: systemColor(name[,defaultValue])
 	 *   - name: system color name
@@ -962,7 +1058,7 @@ class UIDefaultsLoader
 	 *         fadein(color,amount[,options]) or fadeout(color,amount[,options])
 	 *   - color: a color (e.g. #f00) or a color function
 	 *   - amount: percentage 0-100%
-	 *   - options: [relative] [autoInverse] [noAutoInverse] [lazy] [derived]
+	 *   - options: [relative] [autoInverse] [noAutoInverse] [derived] [lazy]
 	 */
 	private static Object parseColorHSLIncreaseDecrease( int hslIndex, boolean increase,
 		List<String> params, Function<String, String> resolver )
@@ -972,15 +1068,15 @@ class UIDefaultsLoader
 		int amount = parsePercentage( params.get( 1 ) );
 		boolean relative = false;
 		boolean autoInverse = false;
-		boolean lazy = false;
 		boolean derived = false;
+		boolean lazy = false;
 
 		if( params.size() > 2 ) {
 			String options = params.get( 2 );
 			relative = options.contains( "relative" );
 			autoInverse = options.contains( "autoInverse" );
-			lazy = options.contains( "lazy" );
 			derived = options.contains( "derived" );
+			lazy = options.contains( "lazy" );
 
 			// use autoInverse by default for derived colors, except if noAutoInverse is set
 			if( derived && !options.contains( "noAutoInverse" ) )
@@ -991,14 +1087,8 @@ class UIDefaultsLoader
 		ColorFunction function = new ColorFunctions.HSLIncreaseDecrease(
 			hslIndex, increase, amount, relative, autoInverse );
 
-		if( lazy ) {
-			return (LazyValue) t -> {
-				Object color = lazyUIManagerGet( colorStr );
-				return (color instanceof Color)
-					? new ColorUIResource( ColorFunctions.applyFunctions( (Color) color, function ) )
-					: null;
-			};
-		}
+		if( lazy )
+			return newLazyColorFunction( colorStr, function );
 
 		// parse base color, apply function and create derived color
 		return parseFunctionBaseColor( colorStr, function, derived, resolver );
@@ -1027,14 +1117,8 @@ class UIDefaultsLoader
 		// create function
 		ColorFunction function = new ColorFunctions.Fade( amount );
 
-		if( lazy ) {
-			return (LazyValue) t -> {
-				Object color = lazyUIManagerGet( colorStr );
-				return (color instanceof Color)
-					? new ColorUIResource( ColorFunctions.applyFunctions( (Color) color, function ) )
-					: null;
-			};
-		}
+		if( lazy )
+			return newLazyColorFunction( colorStr, function );
 
 		// parse base color, apply function and create derived color
 		return parseFunctionBaseColor( colorStr, function, derived, resolver );
@@ -1044,7 +1128,7 @@ class UIDefaultsLoader
 	 * Syntax: spin(color,angle[,options])
 	 *   - color: a color (e.g. #f00) or a color function
 	 *   - angle: number of degrees to rotate
-	 *   - options: [derived]
+	 *   - options: [derived] [lazy]
 	 */
 	private static Object parseColorSpin( List<String> params, Function<String, String> resolver )
 		throws IllegalArgumentException
@@ -1052,15 +1136,20 @@ class UIDefaultsLoader
 		String colorStr = params.get( 0 );
 		int amount = parseInteger( params.get( 1 ) );
 		boolean derived = false;
+		boolean lazy = false;
 
 		if( params.size() > 2 ) {
 			String options = params.get( 2 );
 			derived = options.contains( "derived" );
+			lazy = options.contains( "lazy" );
 		}
 
 		// create function
 		ColorFunction function = new ColorFunctions.HSLIncreaseDecrease( 0, true, amount, false, false );
 
+		if( lazy )
+			return newLazyColorFunction( colorStr, function );
+
 		// parse base color, apply function and create derived color
 		return parseFunctionBaseColor( colorStr, function, derived, resolver );
 	}
@@ -1072,7 +1161,7 @@ class UIDefaultsLoader
 	 *         changeAlpha(color,value[,options])
 	 *   - color: a color (e.g. #f00) or a color function
 	 *   - value: for hue: number of degrees; otherwise: percentage 0-100%
-	 *   - options: [derived]
+	 *   - options: [derived] [lazy]
 	 */
 	private static Object parseColorChange( int hslIndex,
 		List<String> params, Function<String, String> resolver )
@@ -1083,27 +1172,33 @@ class UIDefaultsLoader
 			? parseInteger( params.get( 1 ) )
 			: parsePercentage( params.get( 1 ) );
 		boolean derived = false;
+		boolean lazy = false;
 
 		if( params.size() > 2 ) {
 			String options = params.get( 2 );
 			derived = options.contains( "derived" );
+			lazy = options.contains( "lazy" );
 		}
 
 		// create function
 		ColorFunction function = new ColorFunctions.HSLChange( hslIndex, value );
 
+		if( lazy )
+			return newLazyColorFunction( colorStr, function );
+
 		// parse base color, apply function and create derived color
 		return parseFunctionBaseColor( colorStr, function, derived, resolver );
 	}
 
 	/**
-	 * Syntax: mix(color1,color2[,weight]) or
-	 *         tint(color[,weight]) or
-	 *         shade(color[,weight])
+	 * Syntax: mix(color1,color2[,weight][,options]) or
+	 *         tint(color[,weight][,options]) or
+	 *         shade(color[,weight][,options])
 	 *   - color1: a color (e.g. #f00) or a color function
 	 *   - color2: a color (e.g. #f00) or a color function
 	 *   - weight: the weight (in range 0-100%) to mix the two colors
 	 *             larger weight uses more of first color, smaller weight more of second color
+	 *   - options: [derived] [lazy]
 	 */
 	private static Object parseColorMix( String color1Str, List<String> params, Function<String, String> resolver )
 		throws IllegalArgumentException
@@ -1112,18 +1207,36 @@ class UIDefaultsLoader
 		if( color1Str == null )
 			color1Str = params.get( i++ );
 		String color2Str = params.get( i++ );
-		int weight = (params.size() > i) ? parsePercentage( params.get( i ) ) : 50;
+		int weight = 50;
+		boolean derived = false;
+		boolean lazy = false;
+
+		if( params.size() > i ) {
+			String weightStr = params.get( i );
+			if( !weightStr.isEmpty() && Character.isDigit( weightStr.charAt( 0 ) ) ) {
+				weight = parsePercentage( weightStr );
+				i++;
+			}
+		}
+		if( params.size() > i ) {
+			String options = params.get( i );
+			derived = options.contains( "derived" );
+			lazy = options.contains( "lazy" );
+		}
 
 		// parse second color
-		ColorUIResource color2 = (ColorUIResource) parseColorOrFunction( resolver.apply( color2Str ), resolver );
-		if( color2 == null )
+		ColorUIResource color1 = (ColorUIResource) parseColorOrFunction( resolver.apply( color1Str ), resolver );
+		if( color1 == null )
 			return null;
 
 		// create function
-		ColorFunction function = new ColorFunctions.Mix( color2, weight );
+		ColorFunction function = new ColorFunctions.Mix2( color1, weight );
+
+		if( lazy )
+			return newLazyColorFunction( color2Str, function );
 
 		// parse first color, apply function and create mixed color
-		return parseFunctionBaseColor( color1Str, function, false, resolver );
+		return parseFunctionBaseColor( color2Str, function, derived, resolver );
 	}
 
 	/**
@@ -1217,6 +1330,15 @@ class UIDefaultsLoader
 		return new ColorUIResource( newColor );
 	}
 
+	private static LazyValue newLazyColorFunction( String uiKey, ColorFunction function ) {
+		return (LazyValue) t -> {
+			Object color = lazyUIManagerGet( uiKey );
+			return (color instanceof Color)
+				? new ColorUIResource( ColorFunctions.applyFunctions( (Color) color, function ) )
+				: null;
+		};
+	}
+
 	/**
 	 * Syntax: [normal] [bold|+bold|-bold] [italic|+italic|-italic] [<size>|+<incr>|-<decr>|<percent>%] [family[, family]] [$baseFontKey]
 	 */
@@ -1302,17 +1424,17 @@ class UIDefaultsLoader
 						break;
 				}
 			}
-		} catch( IOException ex ) {
-			throw new IllegalArgumentException( ex );
+		} catch( RuntimeException | IOException ex ) {
+			throw new IllegalArgumentException(  "invalid font '" + value + "' (" + ex.getMessage() + ")" );
 		}
 
 		if( style != -1 && styleChange != 0 )
-			throw new IllegalArgumentException( "can not mix absolute style (e.g. 'bold') with derived style (e.g. '+italic') in '" + value + "'" );
+			throw new IllegalArgumentException( "invalid font '" + value + "': can not mix absolute style (e.g. 'bold') with derived style (e.g. '+italic')" );
 		if( styleChange != 0 ) {
 			if( (styleChange & Font.BOLD) != 0 && (styleChange & (Font.BOLD << 16)) != 0 )
-				throw new IllegalArgumentException( "can not use '+bold' and '-bold' in '" + value + "'" );
+				throw new IllegalArgumentException( "invalid font '" + value + "': can not use '+bold' and '-bold'" );
 			if( (styleChange & Font.ITALIC) != 0 && (styleChange & (Font.ITALIC << 16)) != 0 )
-				throw new IllegalArgumentException( "can not use '+italic' and '-italic' in '" + value + "'" );
+				throw new IllegalArgumentException( "invalid font '" + value + "': can not use '+italic' and '-italic'" );
 		}
 
 		font = new FlatLaf.ActiveFont( baseFontKey, families, style, styleChange, absoluteSize, relativeSize, scaleSize );
@@ -1452,7 +1574,7 @@ class UIDefaultsLoader
 			return (LazyValue) t -> {
 				return new GrayFilter( brightness, contrast, alpha );
 			};
-		} catch( NumberFormatException ex ) {
+		} catch( NumberFormatException | IndexOutOfBoundsException ex ) {
 			throw new IllegalArgumentException( "invalid gray filter '" + value + "'" );
 		}
 	}

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatAbstractIcon.java

@@ -57,6 +57,8 @@ public abstract class FlatAbstractIcon
 //			g2.setColor( Color.blue );
 //			g2.drawRect( x, y, getIconWidth() - 1, getIconHeight() - 1 );
 
+			paintBackground( c, g2, x, y );
+
 			g2.translate( x, y );
 			UIScale.scaleGraphics( g2 );
 
@@ -69,7 +71,11 @@ public abstract class FlatAbstractIcon
 		}
 	}
 
-	protected abstract void paintIcon( Component c, Graphics2D g2 );
+	/** @since 3.5.2 */
+	protected void paintBackground( Component c, Graphics2D g, int x, int y ) {
+	}
+
+	protected abstract void paintIcon( Component c, Graphics2D g );
 
 	@Override
 	public int getIconWidth() {

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatCheckBoxIcon.java

@@ -17,6 +17,7 @@
 package com.formdev.flatlaf.icons;
 
 import static com.formdev.flatlaf.FlatClientProperties.*;
+import static com.formdev.flatlaf.ui.FlatUIUtils.stateColor;
 import java.awt.BasicStroke;
 import java.awt.Color;
 import java.awt.Component;
@@ -48,6 +49,8 @@ import com.formdev.flatlaf.ui.FlatUIUtils;
  * @uiDefault CheckBox.icon.borderWidth					int or float	optional; defaults to Component.borderWidth
  * @uiDefault CheckBox.icon.selectedBorderWidth			int or float	optional; defaults to CheckBox.icon.borderWidth
  * @uiDefault CheckBox.icon.disabledSelectedBorderWidth	int or float	optional; defaults to CheckBox.icon.selectedBorderWidth
+ * @uiDefault CheckBox.icon.indeterminateBorderWidth			int or float	optional; defaults to CheckBox.icon.selectedBorderWidth
+ * @uiDefault CheckBox.icon.disabledIndeterminateBorderWidth	int or float	optional; defaults to CheckBox.icon.disabledSelectedBorderWidth
  * @uiDefault CheckBox.arc								int
  *
  * @uiDefault CheckBox.icon.focusColor					Color	optional; defaults to Component.focusColor
@@ -56,30 +59,45 @@ import com.formdev.flatlaf.ui.FlatUIUtils;
  * @uiDefault CheckBox.icon.selectedBorderColor			Color
  * @uiDefault CheckBox.icon.selectedBackground			Color
  * @uiDefault CheckBox.icon.checkmarkColor				Color
+ * @uiDefault CheckBox.icon.indeterminateBorderColor	Color	optional; defaults to CheckBox.icon.selectedBorderColor
+ * @uiDefault CheckBox.icon.indeterminateBackground		Color	optional; defaults to CheckBox.icon.selectedBackground
+ * @uiDefault CheckBox.icon.indeterminateCheckmarkColor	Color	optional; defaults to CheckBox.icon.checkmarkColor
  *
  * @uiDefault CheckBox.icon.disabledBorderColor					Color
  * @uiDefault CheckBox.icon.disabledBackground					Color
- * @uiDefault CheckBox.icon.disabledSelectedBorderColor	Color	optional; CheckBox.icon.disabledBorderColor is used if not specified
- * @uiDefault CheckBox.icon.disabledSelectedBackground	Color	optional; CheckBox.icon.disabledBackground is used if not specified
+ * @uiDefault CheckBox.icon.disabledSelectedBorderColor			Color	optional; defaults to CheckBox.icon.disabledBorderColor
+ * @uiDefault CheckBox.icon.disabledSelectedBackground			Color	optional; defaults to CheckBox.icon.disabledBackground
  * @uiDefault CheckBox.icon.disabledCheckmarkColor				Color
+ * @uiDefault CheckBox.icon.disabledIndeterminateBorderColor	Color	optional; defaults to CheckBox.icon.disabledSelectedBorderColor
+ * @uiDefault CheckBox.icon.disabledIndeterminateBackground		Color	optional; defaults to CheckBox.icon.disabledSelectedBackground
+ * @uiDefault CheckBox.icon.disabledIndeterminateCheckmarkColor	Color	optional; defaults to CheckBox.icon.disabledCheckmarkColor
  *
  * @uiDefault CheckBox.icon.focusedBorderColor					Color	optional
  * @uiDefault CheckBox.icon.focusedBackground					Color	optional
- * @uiDefault CheckBox.icon.focusedSelectedBorderColor	Color	optional; CheckBox.icon.focusedBorderColor is used if not specified
- * @uiDefault CheckBox.icon.focusedSelectedBackground	Color	optional; CheckBox.icon.focusedBackground is used if not specified
- * @uiDefault CheckBox.icon.focusedCheckmarkColor		Color	optional; CheckBox.icon.checkmarkColor is used if not specified
+ * @uiDefault CheckBox.icon.focusedSelectedBorderColor			Color	optional; defaults to CheckBox.icon.focusedBorderColor
+ * @uiDefault CheckBox.icon.focusedSelectedBackground			Color	optional; defaults to CheckBox.icon.focusedBackground
+ * @uiDefault CheckBox.icon.focusedCheckmarkColor				Color	optional; defaults to CheckBox.icon.checkmarkColor
+ * @uiDefault CheckBox.icon.focusedIndeterminateBorderColor		Color	optional; defaults to CheckBox.icon.focusedSelectedBorderColor
+ * @uiDefault CheckBox.icon.focusedIndeterminateBackground		Color	optional; defaults to CheckBox.icon.focusedSelectedBackground
+ * @uiDefault CheckBox.icon.focusedIndeterminateCheckmarkColor	Color	optional; defaults to CheckBox.icon.focusedCheckmarkColor
  *
  * @uiDefault CheckBox.icon.hoverBorderColor					Color	optional
  * @uiDefault CheckBox.icon.hoverBackground						Color	optional
- * @uiDefault CheckBox.icon.hoverSelectedBorderColor	Color	optional; CheckBox.icon.hoverBorderColor is used if not specified
- * @uiDefault CheckBox.icon.hoverSelectedBackground		Color	optional; CheckBox.icon.hoverBackground is used if not specified
- * @uiDefault CheckBox.icon.hoverCheckmarkColor			Color	optional; CheckBox.icon.checkmarkColor is used if not specified
+ * @uiDefault CheckBox.icon.hoverSelectedBorderColor			Color	optional; defaults to CheckBox.icon.hoverBorderColor
+ * @uiDefault CheckBox.icon.hoverSelectedBackground				Color	optional; defaults to CheckBox.icon.hoverBackground
+ * @uiDefault CheckBox.icon.hoverCheckmarkColor					Color	optional; defaults to CheckBox.icon.checkmarkColor
+ * @uiDefault CheckBox.icon.hoverIndeterminateBorderColor		Color	optional; defaults to CheckBox.icon.hoverSelectedBorderColor
+ * @uiDefault CheckBox.icon.hoverIndeterminateBackground		Color	optional; defaults to CheckBox.icon.hoverSelectedBackground
+ * @uiDefault CheckBox.icon.hoverIndeterminateCheckmarkColor	Color	optional; defaults to CheckBox.icon.hoverCheckmarkColor
  *
  * @uiDefault CheckBox.icon.pressedBorderColor					Color	optional
  * @uiDefault CheckBox.icon.pressedBackground					Color	optional
- * @uiDefault CheckBox.icon.pressedSelectedBorderColor	Color	optional; CheckBox.icon.pressedBorderColor is used if not specified
- * @uiDefault CheckBox.icon.pressedSelectedBackground	Color	optional; CheckBox.icon.pressedBackground is used if not specified
- * @uiDefault CheckBox.icon.pressedCheckmarkColor		Color	optional; CheckBox.icon.checkmarkColor is used if not specified
+ * @uiDefault CheckBox.icon.pressedSelectedBorderColor			Color	optional; defaults to CheckBox.icon.pressedBorderColor
+ * @uiDefault CheckBox.icon.pressedSelectedBackground			Color	optional; defaults to CheckBox.icon.pressedBackground
+ * @uiDefault CheckBox.icon.pressedCheckmarkColor				Color	optional; defaults to CheckBox.icon.checkmarkColor
+ * @uiDefault CheckBox.icon.pressedIndeterminateBorderColor		Color	optional; defaults to CheckBox.icon.pressedSelectedBorderColor
+ * @uiDefault CheckBox.icon.pressedIndeterminateBackground		Color	optional; defaults to CheckBox.icon.pressedSelectedBackground
+ * @uiDefault CheckBox.icon.pressedIndeterminateCheckmarkColor	Color	optional; defaults to CheckBox.icon.pressedCheckmarkColor
  *
  * @author Karl Tauber
  */
@@ -92,6 +110,8 @@ public class FlatCheckBoxIcon
 	/** @since 2 */ @Styleable protected float borderWidth = getUIFloat( "CheckBox.icon.borderWidth", FlatUIUtils.getUIFloat( "Component.borderWidth", 1 ), style );
 	/** @since 2 */ @Styleable protected float selectedBorderWidth = getUIFloat( "CheckBox.icon.selectedBorderWidth", Float.MIN_VALUE, style );
 	/** @since 2 */ @Styleable protected float disabledSelectedBorderWidth = getUIFloat( "CheckBox.icon.disabledSelectedBorderWidth", Float.MIN_VALUE, style );
+	/** @since 3.6 */ @Styleable protected float indeterminateBorderWidth = getUIFloat( "CheckBox.icon.indeterminateBorderWidth", Float.MIN_VALUE, style );
+	/** @since 3.6 */ @Styleable protected float disabledIndeterminateBorderWidth = getUIFloat( "CheckBox.icon.disabledIndeterminateBorderWidth", Float.MIN_VALUE, style );
 	@Styleable protected int arc = FlatUIUtils.getUIInt( "CheckBox.arc", 2 );
 
 	// enabled
@@ -100,6 +120,9 @@ public class FlatCheckBoxIcon
 	@Styleable protected Color selectedBorderColor = getUIColor( "CheckBox.icon.selectedBorderColor", style );
 	@Styleable protected Color selectedBackground = getUIColor( "CheckBox.icon.selectedBackground", style );
 	@Styleable protected Color checkmarkColor = getUIColor( "CheckBox.icon.checkmarkColor", style );
+	/** @since 3.6 */ @Styleable protected Color indeterminateBorderColor = getUIColor( "CheckBox.icon.indeterminateBorderColor", style );
+	/** @since 3.6 */ @Styleable protected Color indeterminateBackground = getUIColor( "CheckBox.icon.indeterminateBackground", style );
+	/** @since 3.6 */ @Styleable protected Color indeterminateCheckmarkColor = getUIColor( "CheckBox.icon.indeterminateCheckmarkColor", style );
 
 	// disabled
 	@Styleable protected Color disabledBorderColor = getUIColor( "CheckBox.icon.disabledBorderColor", style );
@@ -107,6 +130,9 @@ public class FlatCheckBoxIcon
 	/** @since 2 */ @Styleable protected Color disabledSelectedBorderColor = getUIColor( "CheckBox.icon.disabledSelectedBorderColor", style );
 	/** @since 2 */ @Styleable protected Color disabledSelectedBackground = getUIColor( "CheckBox.icon.disabledSelectedBackground", style );
 	@Styleable protected Color disabledCheckmarkColor = getUIColor( "CheckBox.icon.disabledCheckmarkColor", style );
+	/** @since 3.6 */ @Styleable protected Color disabledIndeterminateBorderColor = getUIColor( "CheckBox.icon.disabledIndeterminateBorderColor", style );
+	/** @since 3.6 */ @Styleable protected Color disabledIndeterminateBackground = getUIColor( "CheckBox.icon.disabledIndeterminateBackground", style );
+	/** @since 3.6 */ @Styleable protected Color disabledIndeterminateCheckmarkColor = getUIColor( "CheckBox.icon.disabledIndeterminateCheckmarkColor", style );
 
 	// focused
 	@Styleable protected Color focusedBorderColor = getUIColor( "CheckBox.icon.focusedBorderColor", style );
@@ -114,6 +140,9 @@ public class FlatCheckBoxIcon
 	/** @since 2 */ @Styleable protected Color focusedSelectedBorderColor = getUIColor( "CheckBox.icon.focusedSelectedBorderColor", style );
 	/** @since 2 */ @Styleable protected Color focusedSelectedBackground = getUIColor( "CheckBox.icon.focusedSelectedBackground", style );
 	/** @since 2 */ @Styleable protected Color focusedCheckmarkColor = getUIColor( "CheckBox.icon.focusedCheckmarkColor", style );
+	/** @since 3.6 */ @Styleable protected Color focusedIndeterminateBorderColor = getUIColor( "CheckBox.icon.focusedIndeterminateBorderColor", style );
+	/** @since 3.6 */ @Styleable protected Color focusedIndeterminateBackground = getUIColor( "CheckBox.icon.focusedIndeterminateBackground", style );
+	/** @since 3.6 */ @Styleable protected Color focusedIndeterminateCheckmarkColor = getUIColor( "CheckBox.icon.focusedIndeterminateCheckmarkColor", style );
 
 	// hover
 	@Styleable protected Color hoverBorderColor = getUIColor( "CheckBox.icon.hoverBorderColor", style );
@@ -121,6 +150,9 @@ public class FlatCheckBoxIcon
 	/** @since 2 */ @Styleable protected Color hoverSelectedBorderColor = getUIColor( "CheckBox.icon.hoverSelectedBorderColor", style );
 	/** @since 2 */ @Styleable protected Color hoverSelectedBackground = getUIColor( "CheckBox.icon.hoverSelectedBackground", style );
 	/** @since 2 */ @Styleable protected Color hoverCheckmarkColor = getUIColor( "CheckBox.icon.hoverCheckmarkColor", style );
+	/** @since 3.6 */ @Styleable protected Color hoverIndeterminateBorderColor = getUIColor( "CheckBox.icon.hoverIndeterminateBorderColor", style );
+	/** @since 3.6 */ @Styleable protected Color hoverIndeterminateBackground = getUIColor( "CheckBox.icon.hoverIndeterminateBackground", style );
+	/** @since 3.6 */ @Styleable protected Color hoverIndeterminateCheckmarkColor = getUIColor( "CheckBox.icon.hoverIndeterminateCheckmarkColor", style );
 
 	// pressed
 	/** @since 2 */ @Styleable protected Color pressedBorderColor = getUIColor( "CheckBox.icon.pressedBorderColor", style );
@@ -128,6 +160,9 @@ public class FlatCheckBoxIcon
 	/** @since 2 */ @Styleable protected Color pressedSelectedBorderColor = getUIColor( "CheckBox.icon.pressedSelectedBorderColor", style );
 	/** @since 2 */ @Styleable protected Color pressedSelectedBackground = getUIColor( "CheckBox.icon.pressedSelectedBackground", style );
 	/** @since 2 */ @Styleable protected Color pressedCheckmarkColor = getUIColor( "CheckBox.icon.pressedCheckmarkColor", style );
+	/** @since 3.6 */ @Styleable protected Color pressedIndeterminateBorderColor = getUIColor( "CheckBox.icon.pressedIndeterminateBorderColor", style );
+	/** @since 3.6 */ @Styleable protected Color pressedIndeterminateBackground = getUIColor( "CheckBox.icon.pressedIndeterminateBackground", style );
+	/** @since 3.6 */ @Styleable protected Color pressedIndeterminateCheckmarkColor = getUIColor( "CheckBox.icon.pressedIndeterminateCheckmarkColor", style );
 
 	protected String getPropertyPrefix() {
 		return "CheckBox.";
@@ -182,11 +217,17 @@ public class FlatCheckBoxIcon
 		boolean indeterminate = isIndeterminate( c );
 		boolean selected = indeterminate || isSelected( c );
 		boolean isFocused = FlatUIUtils.isPermanentFocusOwner( c );
-		float bw = selected
-			? (disabledSelectedBorderWidth != Float.MIN_VALUE && !c.isEnabled()
-				? disabledSelectedBorderWidth
-				: (selectedBorderWidth != Float.MIN_VALUE ? selectedBorderWidth : borderWidth))
-			: borderWidth;
+		float bw = Float.MIN_VALUE;
+		if( !c.isEnabled() ) {
+			bw = (indeterminate && disabledIndeterminateBorderWidth != Float.MIN_VALUE)
+				? disabledIndeterminateBorderWidth
+				: (selected ? disabledSelectedBorderWidth : selectedBorderWidth);
+		}
+		if( bw == Float.MIN_VALUE ) {
+			bw = (indeterminate && indeterminateBorderWidth != Float.MIN_VALUE)
+				? indeterminateBorderWidth
+				: ((selected && selectedBorderWidth != Float.MIN_VALUE) ? selectedBorderWidth : borderWidth);
+		}
 
 		// paint focused border
 		if( isFocused && focusWidth > 0 && FlatButtonUI.isFocusPainted( c ) ) {
@@ -195,15 +236,15 @@ public class FlatCheckBoxIcon
 		}
 
 		// paint border
-		g.setColor( getBorderColor( c, selected ) );
+		g.setColor( getBorderColor( c, selected, indeterminate ) );
 		paintBorder( c, g, bw );
 
 		// paint background
-		Color bg = FlatUIUtils.deriveColor( getBackground( c, selected ),
-			selected ? selectedBackground : background );
+		Color baseBg = stateColor( indeterminate, indeterminateBackground, selected, selectedBackground, background );
+		Color bg = FlatUIUtils.deriveColor( getBackground( c, selected, indeterminate ), baseBg );
 		if( bg.getAlpha() < 255 ) {
 			// fill background with default color before filling with non-opaque background
-			g.setColor( selected ? selectedBackground : background );
+			g.setColor( baseBg );
 			paintBackground( c, g, bw );
 		}
 		g.setColor( bg );
@@ -211,7 +252,7 @@ public class FlatCheckBoxIcon
 
 		// paint checkmark
 		if( selected ) {
-			g.setColor( getCheckmarkColor( c ) );
+			g.setColor( getCheckmarkColor( c, indeterminate ) );
 			if( indeterminate )
 				paintIndeterminate( c, g );
 			else
@@ -272,30 +313,33 @@ public class FlatCheckBoxIcon
 		return focusColor;
 	}
 
-	protected Color getBorderColor( Component c, boolean selected ) {
+	/** @since 3.6 */
+	protected Color getBorderColor( Component c, boolean selected, boolean indeterminate ) {
 		return FlatButtonUI.buttonStateColor( c,
-			selected ? selectedBorderColor : borderColor,
-			(selected && disabledSelectedBorderColor != null) ? disabledSelectedBorderColor : disabledBorderColor,
-			(selected && focusedSelectedBorderColor != null) ? focusedSelectedBorderColor : focusedBorderColor,
-			(selected && hoverSelectedBorderColor != null) ? hoverSelectedBorderColor : hoverBorderColor,
-			(selected && pressedSelectedBorderColor != null) ? pressedSelectedBorderColor : pressedBorderColor );
+			stateColor( indeterminate, indeterminateBorderColor,         selected, selectedBorderColor,         borderColor ),
+			stateColor( indeterminate, disabledIndeterminateBorderColor, selected, disabledSelectedBorderColor, disabledBorderColor ),
+			stateColor( indeterminate, focusedIndeterminateBorderColor,  selected, focusedSelectedBorderColor,  focusedBorderColor ),
+			stateColor( indeterminate, hoverIndeterminateBorderColor,    selected, hoverSelectedBorderColor,    hoverBorderColor ),
+			stateColor( indeterminate, pressedIndeterminateBorderColor,  selected, pressedSelectedBorderColor,  pressedBorderColor ) );
 	}
 
-	protected Color getBackground( Component c, boolean selected ) {
+	/** @since 3.6 */
+	protected Color getBackground( Component c, boolean selected, boolean indeterminate ) {
 		return FlatButtonUI.buttonStateColor( c,
-			selected ? selectedBackground : background,
-			(selected && disabledSelectedBackground != null) ? disabledSelectedBackground : disabledBackground,
-			(selected && focusedSelectedBackground != null) ? focusedSelectedBackground : focusedBackground,
-			(selected && hoverSelectedBackground != null) ? hoverSelectedBackground : hoverBackground,
-			(selected && pressedSelectedBackground != null) ? pressedSelectedBackground : pressedBackground );
+			stateColor( indeterminate, indeterminateBackground,          selected, selectedBackground,          background ),
+			stateColor( indeterminate, disabledIndeterminateBackground,  selected, disabledSelectedBackground,  disabledBackground ),
+			stateColor( indeterminate, focusedIndeterminateBackground,   selected, focusedSelectedBackground,   focusedBackground ),
+			stateColor( indeterminate, hoverIndeterminateBackground,     selected, hoverSelectedBackground,     hoverBackground ),
+			stateColor( indeterminate, pressedIndeterminateBackground,   selected, pressedSelectedBackground,   pressedBackground ) );
 	}
 
-	protected Color getCheckmarkColor( Component c ) {
+	/** @since 3.6 */
+	protected Color getCheckmarkColor( Component c, boolean indeterminate ) {
 		return FlatButtonUI.buttonStateColor( c,
-			checkmarkColor,
-			disabledCheckmarkColor,
-			focusedCheckmarkColor,
-			hoverCheckmarkColor,
-			pressedCheckmarkColor );
+			stateColor( indeterminate, indeterminateCheckmarkColor, checkmarkColor ),
+			stateColor( indeterminate, disabledIndeterminateCheckmarkColor, disabledCheckmarkColor ),
+			stateColor( indeterminate, focusedIndeterminateCheckmarkColor, focusedCheckmarkColor ),
+			stateColor( indeterminate, hoverIndeterminateCheckmarkColor, hoverCheckmarkColor ),
+			stateColor( indeterminate, pressedIndeterminateCheckmarkColor, pressedCheckmarkColor ) );
 	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatTabbedPaneCloseIcon.java

@@ -90,7 +90,7 @@ public class FlatTabbedPaneCloseIcon
 				closeSize.width, closeSize.height, closeArc, closeArc );
 		}
 
-		// set cross color
+		// set color of cross
 		Color fg = FlatButtonUI.buttonStateColor( c, closeForeground, null, null, closeHoverForeground, closePressedForeground );
 		g.setColor( FlatUIUtils.deriveColor( fg, c.getForeground() ) );
 

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatTreeOpenIcon.java

@@ -57,11 +57,11 @@ public class FlatTreeOpenIcon
 			double arc = 1.5;
 			double arc2 = 0.5;
 			path = FlatUIUtils.createPath( false,
-				// bottom-left of opend part
+				// bottom-left of opened part
 				2,13.5,
-				// top-left of opend part
+				// top-left of opened part
 				FlatUIUtils.ROUNDED, 4.5,7.5, arc,
-				// top-right of opend part
+				// top-right of opened part
 				FlatUIUtils.ROUNDED, 15.5,7.5, arc2,
 
 				// bottom-right

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatWindowAbstractIcon.java

@@ -18,76 +18,141 @@ package com.formdev.flatlaf.icons;
 
 import java.awt.Color;
 import java.awt.Component;
+import java.awt.Container;
 import java.awt.Dimension;
 import java.awt.Graphics2D;
-import java.awt.RenderingHints;
+import java.awt.Insets;
+import java.awt.Window;
+import javax.swing.SwingUtilities;
 import com.formdev.flatlaf.ui.FlatButtonUI;
+import com.formdev.flatlaf.ui.FlatTitlePane;
 import com.formdev.flatlaf.ui.FlatUIUtils;
+import com.formdev.flatlaf.util.DerivedColor;
 import com.formdev.flatlaf.util.HiDPIUtils;
+import com.formdev.flatlaf.util.UIScale;
 
 /**
  * Base class for window icons.
  *
  * @uiDefault TitlePane.buttonSize						Dimension
+ * @uiDefault TitlePane.buttonInsets					Insets	optional
+ * @uiDefault TitlePane.buttonArc						int		optional
  * @uiDefault TitlePane.buttonSymbolHeight				int
- * @uiDefault TitlePane.buttonHoverBackground			Color
- * @uiDefault TitlePane.buttonPressedBackground			Color
+ * @uiDefault TitlePane.buttonBackground				Color	optional
+ * @uiDefault TitlePane.buttonForeground				Color	optional
+ * @uiDefault TitlePane.buttonInactiveBackground		Color	optional
+ * @uiDefault TitlePane.buttonInactiveForeground		Color	optional
+ * @uiDefault TitlePane.buttonHoverBackground			Color	optional
+ * @uiDefault TitlePane.buttonHoverForeground			Color	optional
+ * @uiDefault TitlePane.buttonPressedBackground			Color	optional
+ * @uiDefault TitlePane.buttonPressedForeground			Color	optional
  *
  * @author Karl Tauber
  */
 public abstract class FlatWindowAbstractIcon
 	extends FlatAbstractIcon
 {
-	private final int symbolHeight;
-	private final Color hoverBackground;
-	private final Color pressedBackground;
+	/** @since 3.6 */ protected final Insets insets;
+	/** @since 3.6 */ protected final int arc;
+	/** @since 3.6 */ protected final int symbolHeight;
+
+	/** @since 3.6 */ protected final Color background;
+	/** @since 3.6 */ protected final Color foreground;
+	/** @since 3.6 */ protected final Color inactiveBackground;
+	/** @since 3.6 */ protected final Color inactiveForeground;
+	protected final Color hoverBackground;
+	/** @since 3.6 */ protected final Color hoverForeground;
+	protected final Color pressedBackground;
+	/** @since 3.6 */ protected final Color pressedForeground;
 
 	/** @since 3.2 */
 	protected FlatWindowAbstractIcon( String windowStyle ) {
-		this( FlatUIUtils.getSubUIDimension( "TitlePane.buttonSize", windowStyle ),
-			FlatUIUtils.getSubUIInt( "TitlePane.buttonSymbolHeight", windowStyle, 10 ),
-			FlatUIUtils.getSubUIColor( "TitlePane.buttonHoverBackground", windowStyle ),
-			FlatUIUtils.getSubUIColor( "TitlePane.buttonPressedBackground", windowStyle ) );
+		this( windowStyle, null, null, null, null, null, null, null, null );
 	}
 
-	/** @since 3.2 */
-	protected FlatWindowAbstractIcon( Dimension size, int symbolHeight, Color hoverBackground, Color pressedBackground ) {
+	/** @since 3.6 */
+	protected FlatWindowAbstractIcon( String windowStyle,
+		Color background, Color foreground, Color inactiveBackground, Color inactiveForeground,
+		Color hoverBackground, Color hoverForeground, Color pressedBackground, Color pressedForeground )
+	{
+		this( FlatUIUtils.getSubUIDimension( "TitlePane.buttonSize", windowStyle ),
+			FlatUIUtils.getSubUIInsets( "TitlePane.buttonInsets", windowStyle ),
+			FlatUIUtils.getSubUIInt( "TitlePane.buttonArc", windowStyle, 0 ),
+			FlatUIUtils.getSubUIInt( "TitlePane.buttonSymbolHeight", windowStyle, 10 ),
+			(background != null) ? background : FlatUIUtils.getSubUIColor( "TitlePane.buttonBackground", windowStyle ),
+			(foreground != null) ? foreground : FlatUIUtils.getSubUIColor( "TitlePane.buttonForeground", windowStyle ),
+			(inactiveBackground != null) ? inactiveBackground : FlatUIUtils.getSubUIColor( "TitlePane.buttonInactiveBackground", windowStyle ),
+			(inactiveForeground != null) ? inactiveForeground : FlatUIUtils.getSubUIColor( "TitlePane.buttonInactiveForeground", windowStyle ),
+			(hoverBackground != null) ? hoverBackground : FlatUIUtils.getSubUIColor( "TitlePane.buttonHoverBackground", windowStyle ),
+			(hoverForeground != null) ? hoverForeground : FlatUIUtils.getSubUIColor( "TitlePane.buttonHoverForeground", windowStyle ),
+			(pressedBackground != null) ? pressedBackground : FlatUIUtils.getSubUIColor( "TitlePane.buttonPressedBackground", windowStyle ),
+			(pressedForeground != null) ? pressedForeground : FlatUIUtils.getSubUIColor( "TitlePane.buttonPressedForeground", windowStyle ) );
+	}
+
+	/** @since 3.6 */
+	protected FlatWindowAbstractIcon( Dimension size, Insets insets, int arc, int symbolHeight,
+		Color background, Color foreground, Color inactiveBackground, Color inactiveForeground,
+		Color hoverBackground, Color hoverForeground, Color pressedBackground, Color pressedForeground )
+	{
 		super( size.width, size.height, null );
+		this.insets = (insets != null) ? insets : new Insets( 0, 0, 0, 0 );
+		this.arc = arc;
 		this.symbolHeight = symbolHeight;
+
+		this.background = background;
+		this.foreground = foreground;
+		this.inactiveBackground = inactiveBackground;
+		this.inactiveForeground = inactiveForeground;
 		this.hoverBackground = hoverBackground;
+		this.hoverForeground = hoverForeground;
 		this.pressedBackground = pressedBackground;
+		this.pressedForeground = pressedForeground;
 	}
 
 	@Override
 	protected void paintIcon( Component c, Graphics2D g ) {
-		paintBackground( c, g );
-
 		g.setColor( getForeground( c ) );
 		HiDPIUtils.paintAtScale1x( g, 0, 0, width, height, this::paintIconAt1x );
 	}
 
 	protected abstract void paintIconAt1x( Graphics2D g, int x, int y, int width, int height, double scaleFactor );
 
-	protected void paintBackground( Component c, Graphics2D g ) {
-		Color background = FlatButtonUI.buttonStateColor( c, null, null, null, hoverBackground, pressedBackground );
+	/** @since 3.5.2 */
+	@Override
+	protected void paintBackground( Component c, Graphics2D g, int x, int y ) {
+		Color bg = null;
+		if( background != null || inactiveBackground != null ) {
+			Window window = SwingUtilities.windowForComponent( c );
+			bg = (window == null || window.isActive()) ? background : inactiveBackground;
+		}
+
+		Color background = FlatButtonUI.buttonStateColor( c, bg, null, null, hoverBackground, pressedBackground );
 		if( background != null ) {
-			// disable antialiasing for background rectangle painting to avoid blury edges when scaled (e.g. at 125% or 175%)
-			Object oldHint = g.getRenderingHint( RenderingHints.KEY_ANTIALIASING );
-			g.setRenderingHint( RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_OFF );
+			Insets insets = UIScale.scale( this.insets );
+			float arc = UIScale.scale( (float) this.arc );
 
-			g.setColor( FlatUIUtils.deriveColor( background, c.getBackground() ) );
-			g.fillRect( 0, 0, width, height );
+			// derive color from title pane background
+			if( background instanceof DerivedColor ) {
+				Container titlePane = SwingUtilities.getAncestorOfClass( FlatTitlePane.class, c );
+				Component baseComp = (titlePane != null) ? titlePane : c;
+				background = FlatUIUtils.deriveColor( background, baseComp.getBackground() );
+			}
 
-			g.setRenderingHint( RenderingHints.KEY_ANTIALIASING, oldHint );
+			g.setColor( background );
+			FlatUIUtils.paintComponentBackground( g, insets.left, insets.top,
+				c.getWidth() - insets.left - insets.right,
+				c.getHeight() - insets.top - insets.bottom,
+				0, arc );
 		}
 	}
 
 	protected Color getForeground( Component c ) {
-		return c.getForeground();
+		Color fg = null;
+		if( foreground != null || inactiveForeground != null ) {
+			Window window = SwingUtilities.windowForComponent( c );
+			fg = (window == null || window.isActive()) ? foreground : inactiveForeground;
 		}
-
-	/** @since 3.2 */
-	protected int getSymbolHeight() {
-		return symbolHeight;
+		return FlatButtonUI.buttonStateColor( c, (fg != null) ? fg : c.getForeground(),
+			null, null, hoverForeground, pressedForeground );
 	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatWindowCloseIcon.java

@@ -17,53 +17,54 @@
 package com.formdev.flatlaf.icons;
 
 import java.awt.BasicStroke;
-import java.awt.Color;
-import java.awt.Component;
 import java.awt.Graphics2D;
 import java.awt.geom.Path2D;
-import com.formdev.flatlaf.ui.FlatButtonUI;
 import com.formdev.flatlaf.ui.FlatUIUtils;
 import com.formdev.flatlaf.util.SystemInfo;
 
 /**
  * "close" icon for windows (frames and dialogs).
  *
- * @uiDefault TitlePane.closeHoverBackground			Color
- * @uiDefault TitlePane.closePressedBackground			Color
- * @uiDefault TitlePane.closeHoverForeground			Color
- * @uiDefault TitlePane.closePressedForeground			Color
+ * @uiDefault TitlePane.closeBackground					Color	optional
+ * @uiDefault TitlePane.closeForeground					Color	optional
+ * @uiDefault TitlePane.closeInactiveBackground			Color	optional
+ * @uiDefault TitlePane.closeInactiveForeground			Color	optional
+ * @uiDefault TitlePane.closeHoverBackground			Color	optional
+ * @uiDefault TitlePane.closeHoverForeground			Color	optional
+ * @uiDefault TitlePane.closePressedBackground			Color	optional
+ * @uiDefault TitlePane.closePressedForeground			Color	optional
  *
  * @author Karl Tauber
  */
 public class FlatWindowCloseIcon
 	extends FlatWindowAbstractIcon
 {
-	private final Color hoverForeground;
-	private final Color pressedForeground;
-
 	public FlatWindowCloseIcon() {
 		this( null );
 	}
 
 	/** @since 3.2 */
 	public FlatWindowCloseIcon( String windowStyle ) {
-		super( FlatUIUtils.getSubUIDimension( "TitlePane.buttonSize", windowStyle ),
-			FlatUIUtils.getSubUIInt( "TitlePane.buttonSymbolHeight", windowStyle, 10 ),
+		super( windowStyle,
+			FlatUIUtils.getSubUIColor( "TitlePane.closeBackground", windowStyle ),
+			FlatUIUtils.getSubUIColor( "TitlePane.closeForeground", windowStyle ),
+			FlatUIUtils.getSubUIColor( "TitlePane.closeInactiveBackground", windowStyle ),
+			FlatUIUtils.getSubUIColor( "TitlePane.closeInactiveForeground", windowStyle ),
 			FlatUIUtils.getSubUIColor( "TitlePane.closeHoverBackground", windowStyle ),
-			FlatUIUtils.getSubUIColor( "TitlePane.closePressedBackground", windowStyle ) );
-
-		hoverForeground = FlatUIUtils.getSubUIColor( "TitlePane.closeHoverForeground", windowStyle );
-		pressedForeground = FlatUIUtils.getSubUIColor( "TitlePane.closePressedForeground", windowStyle );
+			FlatUIUtils.getSubUIColor( "TitlePane.closeHoverForeground", windowStyle ),
+			FlatUIUtils.getSubUIColor( "TitlePane.closePressedBackground", windowStyle ),
+			FlatUIUtils.getSubUIColor( "TitlePane.closePressedForeground", windowStyle ) );
 	}
 
 	@Override
 	protected void paintIconAt1x( Graphics2D g, int x, int y, int width, int height, double scaleFactor ) {
-		int iwh = (int) (getSymbolHeight() * scaleFactor);
+		int iwh = (int) (symbolHeight * scaleFactor);
 		int ix = x + ((width - iwh) / 2);
 		int iy = y + ((height - iwh) / 2);
 		int ix2 = ix + iwh - 1;
 		int iy2 = iy + iwh - 1;
-		float thickness = SystemInfo.isWindows_11_orLater ? (float) scaleFactor : (int) scaleFactor;
+		boolean isWindows10 = SystemInfo.isWindows_10_orLater && !SystemInfo.isWindows_11_orLater;
+		float thickness = Math.max( isWindows10 ? (int) scaleFactor : (float) scaleFactor, 1 );
 
 		Path2D path = new Path2D.Float( Path2D.WIND_EVEN_ODD, 4 );
 		path.moveTo( ix, iy );
@@ -73,9 +74,4 @@ public class FlatWindowCloseIcon
 		g.setStroke( new BasicStroke( thickness ) );
 		g.draw( path );
 	}
-
-	@Override
-	protected Color getForeground( Component c ) {
-		return FlatButtonUI.buttonStateColor( c, c.getForeground(), null, null, hoverForeground, pressedForeground );
-	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatWindowIconifyIcon.java

@@ -37,8 +37,8 @@ public class FlatWindowIconifyIcon
 
 	@Override
 	protected void paintIconAt1x( Graphics2D g, int x, int y, int width, int height, double scaleFactor ) {
-		int iw = (int) (getSymbolHeight() * scaleFactor);
-		int ih = (int) scaleFactor;
+		int iw = (int) (symbolHeight * scaleFactor);
+		int ih = Math.max( (int) scaleFactor, 1 );
 		int ix = x + ((width - iw) / 2);
 		int iy = y + ((height - ih) / 2);
 

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatWindowMaximizeIcon.java

@@ -39,10 +39,11 @@ public class FlatWindowMaximizeIcon
 
 	@Override
 	protected void paintIconAt1x( Graphics2D g, int x, int y, int width, int height, double scaleFactor ) {
-		int iwh = (int) (getSymbolHeight() * scaleFactor);
+		int iwh = (int) (symbolHeight * scaleFactor);
 		int ix = x + ((width - iwh) / 2);
 		int iy = y + ((height - iwh) / 2);
-		float thickness = SystemInfo.isWindows_11_orLater ? (float) scaleFactor : (int) scaleFactor;
+		boolean isWindows10 = SystemInfo.isWindows_10_orLater && !SystemInfo.isWindows_11_orLater;
+		float thickness = Math.max( isWindows10 ? (int) scaleFactor : (float) scaleFactor, 1 );
 		int arc = Math.max( (int) (1.5 * scaleFactor), 2 );
 
 		g.fill( SystemInfo.isWindows_11_orLater

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatWindowRestoreIcon.java

@@ -42,14 +42,15 @@ public class FlatWindowRestoreIcon
 
 	@Override
 	protected void paintIconAt1x( Graphics2D g, int x, int y, int width, int height, double scaleFactor ) {
-		int iwh = (int) (getSymbolHeight() * scaleFactor);
+		int iwh = (int) (symbolHeight * scaleFactor);
 		int ix = x + ((width - iwh) / 2);
 		int iy = y + ((height - iwh) / 2);
-		float thickness = SystemInfo.isWindows_11_orLater ? (float) scaleFactor : (int) scaleFactor;
+		boolean isWindows10 = SystemInfo.isWindows_10_orLater && !SystemInfo.isWindows_11_orLater;
+		float thickness = Math.max( isWindows10 ? (int) scaleFactor : (float) scaleFactor, 1 );
 		int arc = Math.max( (int) (1.5 * scaleFactor), 2 );
 		int arcOuter = (int) (arc + (1.5 * scaleFactor));
 
-		int rwh = (int) ((getSymbolHeight() - 2) * scaleFactor);
+		int rwh = (int) ((symbolHeight - 2) * scaleFactor);
 		int ro2 = iwh - rwh;
 
 		// upper-right rectangle

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatBorder.java

@@ -28,7 +28,6 @@ import javax.swing.JComboBox;
 import javax.swing.JComponent;
 import javax.swing.JScrollPane;
 import javax.swing.JSpinner;
-import javax.swing.JViewport;
 import javax.swing.UIManager;
 import javax.swing.plaf.basic.BasicBorders;
 import com.formdev.flatlaf.FlatClientProperties;
@@ -60,6 +59,8 @@ import com.formdev.flatlaf.util.DerivedColor;
  * @uiDefault Component.error.focusedBorderColor		Color
  * @uiDefault Component.warning.borderColor				Color
  * @uiDefault Component.warning.focusedBorderColor		Color
+ * @uiDefault Component.success.borderColor				Color
+ * @uiDefault Component.success.focusedBorderColor		Color
  * @uiDefault Component.custom.borderColor				Color
  *
  * @author Karl Tauber
@@ -82,6 +83,8 @@ public class FlatBorder
 	@Styleable(dot=true) protected Color errorFocusedBorderColor = UIManager.getColor( "Component.error.focusedBorderColor" );
 	@Styleable(dot=true) protected Color warningBorderColor = UIManager.getColor( "Component.warning.borderColor" );
 	@Styleable(dot=true) protected Color warningFocusedBorderColor = UIManager.getColor( "Component.warning.focusedBorderColor" );
+	/** @since 3.6 */ @Styleable(dot=true) protected Color successBorderColor = UIManager.getColor( "Component.success.borderColor" );
+	/** @since 3.6 */ @Styleable(dot=true) protected Color successFocusedBorderColor = UIManager.getColor( "Component.success.focusedBorderColor" );
 	@Styleable(dot=true) protected Color customBorderColor = UIManager.getColor( "Component.custom.borderColor" );
 
 	// only used via styling (not in UI defaults, but has likewise client properties)
@@ -136,7 +139,7 @@ public class FlatBorder
 			Paint borderColor = (outlineColor != null) ? outlineColor : getBorderColor( c );
 			FlatUIUtils.paintOutlinedComponent( g2, x, y, width, height,
 				focusWidth, 1, focusInnerWidth, borderWidth, arc,
-				focusColor, borderColor, null );
+				focusColor, borderColor, null, c instanceof JScrollPane );
 		} finally {
 			g2.dispose();
 		}
@@ -169,6 +172,9 @@ public class FlatBorder
 
 				case FlatClientProperties.OUTLINE_WARNING:
 					return isFocused( c ) ? warningFocusedBorderColor : warningBorderColor;
+
+				case FlatClientProperties.OUTLINE_SUCCESS:
+					return isFocused( c ) ? successFocusedBorderColor : successBorderColor;
 			}
 		} else if( outline instanceof Color ) {
 			Color color = (Color) outline;
@@ -195,8 +201,7 @@ public class FlatBorder
 	protected boolean isEnabled( Component c ) {
 		if( c instanceof JScrollPane ) {
 			// check whether view component is disabled
-			JViewport viewport = ((JScrollPane)c).getViewport();
-			Component view = (viewport != null) ? viewport.getView() : null;
+			Component view = FlatScrollPaneUI.getView( (JScrollPane) c );
 			if( view != null && !isEnabled( view ) )
 				return false;
 		}
@@ -279,7 +284,7 @@ public class FlatBorder
 	}
 
 	/**
-	 * Returns the (unscaled) arc diameter of the border.
+	 * Returns the (unscaled) arc diameter of the border corners.
 	 */
 	protected int getArc( Component c ) {
 		return 0;

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatButtonBorder.java

@@ -42,6 +42,13 @@ import com.formdev.flatlaf.util.UIScale;
  * @uiDefault Button.disabledBorderColor		Color
  * @uiDefault Button.focusedBorderColor			Color
  * @uiDefault Button.hoverBorderColor			Color	optional
+ * @uiDefault Button.pressedBorderColor			Color	optional
+ *
+ * @uiDefault Button.selectedBorderColor		Color	optional
+ * @uiDefault Button.disabledSelectedBorderColor Color	optional
+ * @uiDefault Button.focusedSelectedBorderColor	Color	optional
+ * @uiDefault Button.hoverSelectedBorderColor	Color	optional
+ * @uiDefault Button.pressedSelectedBorderColor	Color	optional
  *
  * @uiDefault Button.default.borderWidth		int or float
  * @uiDefault Button.default.borderColor		Color
@@ -49,6 +56,7 @@ import com.formdev.flatlaf.util.UIScale;
  * @uiDefault Button.default.endBorderColor		Color	optional; if set, a gradient paint is used
  * @uiDefault Button.default.focusedBorderColor	Color
  * @uiDefault Button.default.focusColor			Color
+ * @uiDefault Button.default.pressedBorderColor	Color	optional
  * @uiDefault Button.default.hoverBorderColor	Color	optional
  *
  * @uiDefault Button.toolbar.focusWidth			int or float		optional; default is 1.5
@@ -65,6 +73,13 @@ public class FlatButtonBorder
 
 	protected Color endBorderColor = UIManager.getColor( "Button.endBorderColor" );
 	@Styleable protected Color hoverBorderColor = UIManager.getColor( "Button.hoverBorderColor" );
+	/** @since 3.5 */ @Styleable protected Color pressedBorderColor = UIManager.getColor( "Button.pressedBorderColor" );
+
+	/** @since 3.5 */ @Styleable protected Color selectedBorderColor = UIManager.getColor( "Button.selectedBorderColor" );
+	/** @since 3.5 */ @Styleable protected Color disabledSelectedBorderColor = UIManager.getColor( "Button.disabledSelectedBorderColor" );
+	/** @since 3.5 */ @Styleable protected Color focusedSelectedBorderColor = UIManager.getColor( "Button.focusedSelectedBorderColor" );
+	/** @since 3.5 */ @Styleable protected Color hoverSelectedBorderColor = UIManager.getColor( "Button.hoverSelectedBorderColor" );
+	/** @since 3.5 */ @Styleable protected Color pressedSelectedBorderColor = UIManager.getColor( "Button.pressedSelectedBorderColor" );
 
 	@Styleable(dot=true) protected float defaultBorderWidth = FlatUIUtils.getUIFloat( "Button.default.borderWidth", 1 );
 	@Styleable(dot=true) protected Color defaultBorderColor = FlatUIUtils.getUIColor( "Button.default.startBorderColor", "Button.default.borderColor" );
@@ -72,6 +87,7 @@ public class FlatButtonBorder
 	@Styleable(dot=true) protected Color defaultFocusedBorderColor = UIManager.getColor( "Button.default.focusedBorderColor" );
 	@Styleable(dot=true) protected Color defaultFocusColor = UIManager.getColor( "Button.default.focusColor" );
 	@Styleable(dot=true) protected Color defaultHoverBorderColor = UIManager.getColor( "Button.default.hoverBorderColor" );
+	/** @since 3.5 */ @Styleable(dot=true) protected Color defaultPressedBorderColor = UIManager.getColor( "Button.default.pressedBorderColor" );
 
 	/** @since 1.4 */ @Styleable(dot=true) protected float toolbarFocusWidth = FlatUIUtils.getUIFloat( "Button.toolbar.focusWidth", 1.5f );
 	/** @since 1.4 */ @Styleable(dot=true) protected Color toolbarFocusColor = UIManager.getColor( "Button.toolbar.focusColor" );
@@ -139,12 +155,13 @@ public class FlatButtonBorder
 	@Override
 	protected Paint getBorderColor( Component c ) {
 		boolean def = FlatButtonUI.isDefaultButton( c );
+		boolean selected = (c instanceof AbstractButton && ((AbstractButton)c).isSelected());
 		Paint color = FlatButtonUI.buttonStateColor( c,
-			def ? defaultBorderColor : borderColor,
-			disabledBorderColor,
-			def ? defaultFocusedBorderColor : focusedBorderColor,
-			def ? defaultHoverBorderColor : hoverBorderColor,
-			null );
+			def ? defaultBorderColor : ((selected && selectedBorderColor != null) ? selectedBorderColor : borderColor),
+			(selected && disabledSelectedBorderColor != null) ? disabledSelectedBorderColor : disabledBorderColor,
+			def ? defaultFocusedBorderColor : ((selected && focusedSelectedBorderColor != null) ? focusedSelectedBorderColor : focusedBorderColor),
+			def ? defaultHoverBorderColor : ((selected && hoverSelectedBorderColor != null) ? hoverSelectedBorderColor : hoverBorderColor),
+			def ? defaultPressedBorderColor : ((selected && pressedSelectedBorderColor != null) ? pressedSelectedBorderColor : pressedBorderColor) );
 
 		// change to gradient paint if start/end colors are specified
 		Color startBg = def ? defaultBorderColor : borderColor;

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatButtonUI.java

@@ -29,6 +29,7 @@ import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.Insets;
 import java.awt.Rectangle;
+import java.awt.event.FocusEvent;
 import java.awt.geom.RoundRectangle2D;
 import java.beans.PropertyChangeEvent;
 import java.util.Map;
@@ -61,6 +62,7 @@ import com.formdev.flatlaf.icons.FlatHelpButtonIcon;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
 import com.formdev.flatlaf.ui.FlatStylingSupport.UnknownStyleException;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.UIScale;
 
@@ -278,8 +280,6 @@ public class FlatButtonUI
 
 		LookAndFeel.installProperty( b, "opaque", false );
 		LookAndFeel.installProperty( b, "iconTextGap", scale( iconTextGap ) );
-
-		MigLayoutVisualPadding.install( b );
 	}
 
 	@Override
@@ -289,10 +289,23 @@ public class FlatButtonUI
 		oldStyleValues = null;
 		borderShared = null;
 
-		MigLayoutVisualPadding.uninstall( b );
 		defaults_initialized = false;
 	}
 
+	@Override
+	protected void installListeners( AbstractButton b ) {
+		super.installListeners( b );
+
+		MigLayoutVisualPadding.install( b );
+	}
+
+	@Override
+	protected void uninstallListeners( AbstractButton b ) {
+		super.uninstallListeners( b );
+
+		MigLayoutVisualPadding.uninstall( b );
+	}
+
 	@Override
 	protected BasicButtonListener createButtonListener( AbstractButton b ) {
 		return new FlatButtonListener( b );
@@ -300,6 +313,10 @@ public class FlatButtonUI
 
 	protected void propertyChange( AbstractButton b, PropertyChangeEvent e ) {
 		switch( e.getPropertyName() ) {
+			case BasicHTML.propertyKey:
+				FlatHTML.updateRendererCSSFontBaseSize( b );
+				break;
+
 			case SQUARE_SIZE:
 			case MINIMUM_WIDTH:
 			case MINIMUM_HEIGHT:
@@ -308,11 +325,11 @@ public class FlatButtonUI
 
 			case BUTTON_TYPE:
 				b.revalidate();
-				b.repaint();
+				HiDPIUtils.repaint( b );
 				break;
 
 			case OUTLINE:
-				b.repaint();
+				HiDPIUtils.repaint( b );
 				break;
 
 			case STYLE:
@@ -324,7 +341,7 @@ public class FlatButtonUI
 				} else
 					installStyle( b );
 				b.revalidate();
-				b.repaint();
+				HiDPIUtils.repaint( b );
 				break;
 		}
 	}
@@ -364,6 +381,12 @@ public class FlatButtonUI
 			return ((FlatHelpButtonIcon)helpButtonIcon).applyStyleProperty( key, value );
 		}
 
+		// update internal values; otherwise isCustomBackground() and isCustomForeground() would return wrong results
+		switch( key ) {
+			case "background":	background = (Color) value; break;
+			case "foreground":	foreground = (Color) value; break;
+		}
+
 		if( "iconTextGap".equals( key ) && value instanceof Integer )
 			value = UIScale.scale( (Integer) value );
 
@@ -583,9 +606,16 @@ public class FlatButtonUI
 		// paint text
 		if( clippedText != null && !clippedText.isEmpty() ) {
 			View view = (View) b.getClientProperty( BasicHTML.propertyKey );
-			if( view != null )
+			if( view != null ) {
+				// update foreground color in HTML view, which is necessary
+				// for selected and pressed states
+				// (only for enabled buttons, because UIManager.getColor("textInactiveText")
+				// is used for disabled components; see: javax.swing.text.GlyphView.paint())
+				if( b.isEnabled() )
+					FlatHTML.updateRendererCSSForeground( view, getForeground( b ) );
+
 				view.paint( g, textR ); // HTML text
-			else
+			} else
 				paintText( g, b, textR, clippedText );
 		}
 
@@ -631,8 +661,6 @@ public class FlatButtonUI
 	}
 
 	public static void paintText( Graphics g, AbstractButton b, Rectangle textRect, String text, Color foreground ) {
-		if(foreground == null)
-			foreground=Color.red;
 		FontMetrics fm = b.getFontMetrics( b.getFont() );
 		int mnemonicIndex = FlatLaf.isShowMnemonics() ? b.getDisplayedMnemonicIndex() : -1;
 
@@ -642,7 +670,8 @@ public class FlatButtonUI
 	}
 
 	protected Color getBackground( JComponent c ) {
-		boolean toolBarButton = isToolBarButton( c ) || isBorderlessButton( c );
+		boolean def = isDefaultButton( c );
+		boolean toolBarButton = !def && (isToolBarButton( c ) || isBorderlessButton( c ));
 
 		// selected state
 		if( ((AbstractButton)c).isSelected() ) {
@@ -670,7 +699,6 @@ public class FlatButtonUI
 				toolbarPressedBackground );
 		}
 
-		boolean def = isDefaultButton( c );
 		return buttonStateColor( c,
 			getBackgroundBase( c, def ),
 			disabledBackground,
@@ -721,14 +749,16 @@ public class FlatButtonUI
 	}
 
 	protected Color getForeground( JComponent c ) {
-		boolean toolBarButton = isToolBarButton( c ) || isBorderlessButton( c );
+		Color fg = c.getForeground();
+		boolean def = isDefaultButton( c );
+		boolean toolBarButton = !def && (isToolBarButton( c ) || isBorderlessButton( c ));
 
 		// selected state
 		if( ((AbstractButton)c).isSelected() ) {
 			return buttonStateColor( c,
 				toolBarButton
-					? (toolbarSelectedForeground != null ? toolbarSelectedForeground : c.getForeground())
-					: selectedForeground,
+					? (toolbarSelectedForeground != null ? toolbarSelectedForeground : fg)
+					: (isCustomForeground( fg ) ? fg : selectedForeground),
 				toolBarButton
 					? (toolbarDisabledSelectedForeground != null ? toolbarDisabledSelectedForeground : disabledText)
 					: (disabledSelectedForeground != null ? disabledSelectedForeground : disabledText),
@@ -740,18 +770,17 @@ public class FlatButtonUI
 		// toolbar button
 		if( toolBarButton ) {
 			return buttonStateColor( c,
-				c.getForeground(),
+				fg,
 				disabledText,
 				null,
 				toolbarHoverForeground,
 				toolbarPressedForeground );
 		}
 
-		boolean def = isDefaultButton( c );
 		return buttonStateColor( c,
 			getForegroundBase( c, def ),
 			disabledText,
-			isCustomForeground( c.getForeground() ) ? null : (def ? defaultFocusedForeground : focusedForeground),
+			isCustomForeground( fg ) ? null : (def ? defaultFocusedForeground : focusedForeground),
 			def ? defaultHoverForeground : hoverForeground,
 			def ? defaultPressedForeground : pressedForeground );
 	}
@@ -905,7 +934,7 @@ public class FlatButtonUI
 
 		@Override
 		public void stateChanged( ChangeEvent e ) {
-			super.stateChanged( e );
+			HiDPIUtils.repaint( b );
 
 			// if button is in toolbar, repaint button groups
 			AbstractButton b = (AbstractButton) e.getSource();
@@ -917,5 +946,17 @@ public class FlatButtonUI
 					((FlatToolBarUI)ui).repaintButtonGroup( b );
 			}
 		}
+
+		@Override
+		public void focusGained( FocusEvent e ) {
+			super.focusGained( e );
+			HiDPIUtils.repaint( b );
+		}
+
+		@Override
+		public void focusLost( FocusEvent e ) {
+			super.focusLost( e );
+			HiDPIUtils.repaint( b );
+		}
 	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatCaret.java

@@ -17,6 +17,7 @@
 package com.formdev.flatlaf.ui;
 
 import static com.formdev.flatlaf.FlatClientProperties.*;
+import java.awt.Container;
 import java.awt.EventQueue;
 import java.awt.Rectangle;
 import java.awt.event.ActionEvent;
@@ -24,7 +25,9 @@ import java.awt.event.FocusEvent;
 import java.awt.event.MouseEvent;
 import javax.swing.Action;
 import javax.swing.ActionMap;
+import javax.swing.JComboBox;
 import javax.swing.JFormattedTextField;
+import javax.swing.JSpinner;
 import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
 import javax.swing.plaf.UIResource;
@@ -33,6 +36,7 @@ import javax.swing.text.DefaultCaret;
 import javax.swing.text.DefaultEditorKit;
 import javax.swing.text.Document;
 import javax.swing.text.JTextComponent;
+import javax.swing.text.Position;
 import javax.swing.text.Utilities;
 
 /**
@@ -48,12 +52,15 @@ public class FlatCaret
 {
 	private static final String KEY_CARET_INFO = "FlatLaf.internal.caretInfo";
 
+	// selectAllOnFocusPolicy
+	private static final int NEVER = 0, ONCE = 1, ALWAYS = 2;
+
 	private final String selectAllOnFocusPolicy;
 	private final boolean selectAllOnMouseClick;
 
 	private boolean inInstall;
 	private boolean wasFocused;
-	private boolean wasTemporaryLost;
+	private boolean wasFocusTemporaryLost;
 	private boolean isMousePressed;
 	private boolean isWordSelection;
 	private boolean isLineSelection;
@@ -94,6 +101,9 @@ public class FlatCaret
 			// restore selection
 			select( (int) ci[1], (int) ci[0] );
 
+			if( ci[4] != 0 )
+				wasFocused = true;
+
 			// if text component is focused, then caret and selection are visible,
 			// but when switching theme, the component does not yet have
 			// a highlighter and the selection is not painted
@@ -121,6 +131,7 @@ public class FlatCaret
 			getMark(),
 			getBlinkRate(),
 			System.currentTimeMillis(),
+			wasFocused ? 1 : 0,
 		} );
 
 		super.deinstall( c );
@@ -140,11 +151,36 @@ public class FlatCaret
 		super.adjustVisibility( nloc );
 	}
 
+	@Override
+	public void setDot( int dot ) {
+		super.setDot( dot );
+
+		// mark as focused if invoked from JTextComponent.setCaretPosition()
+		// to disable SELECT_ALL_ON_FOCUS_POLICY_ONCE if application explicitly changes selection
+		if( !wasFocused &&
+			getSelectAllOnFocusPolicy() == ONCE &&
+			StackUtils.wasInvokedFrom( JTextComponent.class.getName(), "setCaretPosition", 6 ) )
+		  wasFocused = true;
+	}
+
+	@Override
+	public void moveDot( int dot ) {
+		super.moveDot( dot );
+
+		// mark as focused if invoked from JTextComponent.moveCaretPosition()
+		// to disable SELECT_ALL_ON_FOCUS_POLICY_ONCE if application explicitly changes selection
+		if( !wasFocused &&
+			getSelectAllOnFocusPolicy() == ONCE &&
+			StackUtils.wasInvokedFrom( JTextComponent.class.getName(), "moveCaretPosition", 6 ) )
+		  wasFocused = true;
+	}
+
 	@Override
 	public void focusGained( FocusEvent e ) {
-		if( !inInstall && !wasTemporaryLost && (!isMousePressed || selectAllOnMouseClick) )
+		if( !inInstall && !wasFocusTemporaryLost && (!isMousePressed || isSelectAllOnMouseClick()) )
 			selectAllOnFocusGained();
-		wasTemporaryLost = false;
+
+		wasFocusTemporaryLost = false;
 		wasFocused = true;
 
 		super.focusGained( e );
@@ -152,7 +188,7 @@ public class FlatCaret
 
 	@Override
 	public void focusLost( FocusEvent e ) {
-		wasTemporaryLost = e.isTemporary();
+		wasFocusTemporaryLost = e.isTemporary();
 		super.focusLost( e );
 	}
 
@@ -232,24 +268,13 @@ public class FlatCaret
 		if( doc == null || !c.isEnabled() || !c.isEditable() || FlatUIUtils.isCellEditor( c ) )
 			return;
 
-		Object selectAllOnFocusPolicy = c.getClientProperty( SELECT_ALL_ON_FOCUS_POLICY );
-		if( selectAllOnFocusPolicy == null )
-			selectAllOnFocusPolicy = this.selectAllOnFocusPolicy;
-
-		if( selectAllOnFocusPolicy == null || SELECT_ALL_ON_FOCUS_POLICY_NEVER.equals( selectAllOnFocusPolicy ) )
+		int selectAllOnFocusPolicy = getSelectAllOnFocusPolicy();
+		if( selectAllOnFocusPolicy == NEVER )
 			return;
 
-		if( !SELECT_ALL_ON_FOCUS_POLICY_ALWAYS.equals( selectAllOnFocusPolicy ) ) {
-			// policy is "once" (or null or unknown)
-
+		if( selectAllOnFocusPolicy == ONCE && !isMousePressed ) {
 			// was already focused?
-			if( wasFocused )
-				return;
-
-			// check whether selection was modified before gaining focus
-			int dot = getDot();
-			int mark = getMark();
-			if( dot != mark || dot != doc.getLength() )
+			if( wasFocused && !(c instanceof JFormattedTextField) )
 				return;
 		}
 
@@ -265,16 +290,51 @@ public class FlatCaret
 
 				select( 0, c2.getDocument().getLength() );
 			} );
-		} else {
+		} else
 			select( 0, doc.getLength() );
 	}
-	}
 
 	private void select( int mark, int dot ) {
 		if( mark != getMark() )
-			setDot( mark );
+			setDot( mark, Position.Bias.Forward );
 		if( dot != getDot() )
-			moveDot( dot );
+			moveDot( dot, Position.Bias.Forward );
+	}
+
+	private int getSelectAllOnFocusPolicy() {
+		Object value = getClientProperty( SELECT_ALL_ON_FOCUS_POLICY );
+		// Note: using String.valueOf() because selectAllOnFocusPolicy may be null
+		switch( String.valueOf( value instanceof String ? value : selectAllOnFocusPolicy ) ) {
+			default:
+			case SELECT_ALL_ON_FOCUS_POLICY_NEVER:  return NEVER;
+			case SELECT_ALL_ON_FOCUS_POLICY_ONCE:   return ONCE;
+			case SELECT_ALL_ON_FOCUS_POLICY_ALWAYS: return ALWAYS;
+		}
+	}
+
+	private boolean isSelectAllOnMouseClick() {
+		Object value = getClientProperty( SELECT_ALL_ON_MOUSE_CLICK );
+		return (value instanceof Boolean) ? (boolean) value : selectAllOnMouseClick;
+	}
+
+	private Object getClientProperty( String key ) {
+		JTextComponent c = getComponent();
+		if( c == null )
+			return null;
+
+		Object value = c.getClientProperty( key );
+		if( value != null )
+			return value;
+
+		Container parent = c.getParent();
+		if( parent instanceof JComboBox )
+			return ((JComboBox<?>)parent).getClientProperty( key );
+		if( parent instanceof JSpinner.DefaultEditor ) {
+			parent = parent.getParent();
+			if( parent instanceof JSpinner )
+				return ((JSpinner)parent).getClientProperty( key );
+		}
+		return null;
 	}
 
 	/** @since 1.4 */

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatCheckBoxMenuItemUI.java

@@ -23,6 +23,7 @@ import java.lang.invoke.MethodHandles;
 import java.util.Map;
 import javax.swing.Icon;
 import javax.swing.JComponent;
+import javax.swing.JMenuItem;
 import javax.swing.LookAndFeel;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.basic.BasicCheckBoxMenuItemUI;
@@ -102,13 +103,23 @@ public class FlatCheckBoxMenuItemUI
 		oldStyleValues = null;
 	}
 
+	@Override
+	protected void installComponents( JMenuItem menuItem ) {
+		super.installComponents( menuItem );
+
+		// update HTML renderer if necessary
+		FlatHTML.updateRendererCSSFontBaseSize( menuItem );
+	}
+
 	protected FlatMenuItemRenderer createRenderer() {
 		return new FlatMenuItemRenderer( menuItem, checkIcon, arrowIcon, acceleratorFont, acceleratorDelimiter );
 	}
 
 	@Override
 	protected PropertyChangeListener createPropertyChangeListener( JComponent c ) {
-		return FlatStylingSupport.createPropertyChangeListener( c, this::installStyle, super.createPropertyChangeListener( c ) );
+		return FlatHTML.createPropertyChangeListener(
+			FlatStylingSupport.createPropertyChangeListener( c, this::installStyle,
+				super.createPropertyChangeListener( c ) ) );
 	}
 
 	/** @since 2 */

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatComboBoxUI.java

@@ -78,6 +78,7 @@ import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableField;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableLookupProvider;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.SystemInfo;
 
@@ -220,10 +221,12 @@ public class FlatComboBoxUI
 
 			private void repaintArrowButton() {
 				if( arrowButton != null && !comboBox.isEditable() )
-					arrowButton.repaint();
+					HiDPIUtils.repaint( arrowButton );
 			}
 		};
 		comboBox.addMouseListener( hoverListener );
+
+		MigLayoutVisualPadding.install( comboBox );
 	}
 
 	@Override
@@ -232,6 +235,8 @@ public class FlatComboBoxUI
 
 		comboBox.removeMouseListener( hoverListener );
 		hoverListener = null;
+
+		MigLayoutVisualPadding.uninstall( comboBox );
 	}
 
 	@Override
@@ -273,8 +278,6 @@ public class FlatComboBoxUI
 			comboBox.setMaximumRowCount( maximumRowCount );
 
 		paddingBorder = new CellPaddingBorder( padding );
-
-		MigLayoutVisualPadding.install( comboBox );
 	}
 
 	@Override
@@ -303,8 +306,6 @@ public class FlatComboBoxUI
 
 		oldStyleValues = null;
 		borderShared = null;
-
-		MigLayoutVisualPadding.uninstall( comboBox );
 	}
 
 	@Override
@@ -351,15 +352,15 @@ public class FlatComboBoxUI
 			@Override
 			public void focusGained( FocusEvent e ) {
 				super.focusGained( e );
-				if( comboBox != null && comboBox.isEditable() )
-					comboBox.repaint();
+				if( comboBox != null )
+					HiDPIUtils.repaint( comboBox );
 			}
 
 			@Override
 			public void focusLost( FocusEvent e ) {
 				super.focusLost( e );
-				if( comboBox != null && comboBox.isEditable() )
-					comboBox.repaint();
+				if( comboBox != null )
+					HiDPIUtils.repaint( comboBox );
 			}
 		};
 	}
@@ -386,12 +387,12 @@ public class FlatComboBoxUI
 				switch( propertyName ) {
 					case PLACEHOLDER_TEXT:
 						if( editor != null )
-							editor.repaint();
+							HiDPIUtils.repaint( editor );
 						break;
 
 					case COMPONENT_ROUND_RECT:
 					case OUTLINE:
-						comboBox.repaint();
+						HiDPIUtils.repaint( comboBox );
 						break;
 
 					case MINIMUM_WIDTH:
@@ -402,7 +403,7 @@ public class FlatComboBoxUI
 					case STYLE_CLASS:
 						installStyle();
 						comboBox.revalidate();
-						comboBox.repaint();
+						HiDPIUtils.repaint( comboBox );
 						break;
 				}
 			}
@@ -584,7 +585,7 @@ public class FlatComboBoxUI
 			FlatUIUtils.paintComponentBackground( g2, 0, 0, width, height, focusWidth, arc );
 
 			// paint arrow button background
-			if( enabled && !isCellRenderer ) {
+			if( enabled && !isCellRenderer && arrowButton.isVisible() ) {
 				Color buttonColor = paintButton
 					? buttonEditableBackground
 					: (buttonFocusedBackground != null || focusedBackground != null) && isPermanentFocusOwner( comboBox )
@@ -611,7 +612,7 @@ public class FlatComboBoxUI
 			}
 
 			// paint vertical line between value and arrow button
-			if( paintButton ) {
+			if( paintButton && arrowButton.isVisible() ) {
 				Color separatorColor = enabled ? buttonSeparatorColor : buttonDisabledSeparatorColor;
 				if( separatorColor != null && buttonSeparatorWidth > 0 ) {
 					g2.setColor( separatorColor );
@@ -881,7 +882,7 @@ public class FlatComboBoxUI
 				GraphicsConfiguration gc = comboBox.getGraphicsConfiguration();
 				if( gc != null ) {
 					Rectangle screenBounds = gc.getBounds();
-					Insets screenInsets = Toolkit.getDefaultToolkit().getScreenInsets( gc );
+					Insets screenInsets = FlatUIUtils.getScreenInsets( gc );
 					displayWidth = Math.min( displayWidth, screenBounds.width - screenInsets.left - screenInsets.right );
 				} else {
 					Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
@@ -926,7 +927,7 @@ public class FlatComboBoxUI
 		protected void configurePopup() {
 			super.configurePopup();
 
-			// make opaque to avoid that background shines thru border (e.g. at 150% scaling)
+			// make opaque to avoid that background shines through border (e.g. at 150% scaling)
 			setOpaque( true );
 
 			// set popup border
@@ -944,7 +945,7 @@ public class FlatComboBoxUI
 			if( popupBackground != null )
 				list.setBackground( popupBackground );
 
-			// set popup background because it may shine thru when scaled (e.g. at 150%)
+			// set popup background because it may shine through when scaled (e.g. at 150%)
 			// use non-UIResource to avoid that it is overwritten when making
 			// popup visible (see JPopupMenu.setInvoker()) in theme editor preview
 			setBackground( FlatUIUtils.nonUIResource( list.getBackground() ) );
@@ -1090,7 +1091,7 @@ public class FlatComboBoxUI
 		}
 
 		// using synchronized to avoid problems with code that modifies combo box
-		// (model, selection, etc) not on AWT thread (which should be not done)
+		// (model, selection, etc.) not on AWT thread (which should be not done)
 		synchronized void install( Component c, int focusWidth ) {
 			if( !(c instanceof JComponent) )
 				return;
@@ -1242,7 +1243,7 @@ public class FlatComboBoxUI
 	 * Key selection manager that delegates to the default manager.
 	 * Shows the popup if Space key is pressed and "typed characters" buffer is empty.
 	 * If items contain spaces (e.g. "a b") it is still possible to select them
-	 * by pressing keys a, Space and b.
+	 * by pressing keys 'a', 'Space' and 'b'.
 	 */
 	private class FlatKeySelectionManager
 		implements JComboBox.KeySelectionManager, UIResource

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatDropShadowBorder.java

@@ -74,7 +74,7 @@ public class FlatDropShadowBorder
 
 		this.shadowColor = shadowColor;
 		this.shadowInsets = shadowInsets;
-		this.shadowOpacity = shadowOpacity;
+		this.shadowOpacity = Math.min( Math.max( shadowOpacity, 0f ), 1f );
 
 		shadowSize = maxInset( shadowInsets );
 	}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatEditorPaneUI.java

@@ -171,7 +171,7 @@ public class FlatEditorPaneUI
 			case FlatClientProperties.STYLE_CLASS:
 				installStyle.run();
 				c.revalidate();
-				c.repaint();
+				HiDPIUtils.repaint( c );
 				break;
 		}
 	}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatFileChooserUI.java

@@ -24,6 +24,7 @@ import java.awt.Graphics2D;
 import java.awt.Image;
 import java.awt.Insets;
 import java.awt.LayoutManager;
+import java.awt.Rectangle;
 import java.awt.RenderingHints;
 import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
@@ -32,6 +33,7 @@ import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.function.Function;
 import javax.swing.AbstractButton;
+import javax.swing.BorderFactory;
 import javax.swing.Box;
 import javax.swing.BoxLayout;
 import javax.swing.ButtonGroup;
@@ -46,6 +48,7 @@ import javax.swing.JScrollPane;
 import javax.swing.JTable;
 import javax.swing.JToggleButton;
 import javax.swing.JToolBar;
+import javax.swing.Scrollable;
 import javax.swing.SwingConstants;
 import javax.swing.UIManager;
 import javax.swing.filechooser.FileSystemView;
@@ -164,6 +167,7 @@ public class FlatFileChooserUI
 {
 	private final FlatFileView fileView = new FlatFileView();
 	private FlatShortcutsPanel shortcutsPanel;
+	private JScrollPane shortcutsScrollPane;
 
 	public static ComponentUI createUI( JComponent c ) {
 		return new FlatFileChooserUI( (JFileChooser) c );
@@ -183,7 +187,10 @@ public class FlatFileChooserUI
 			FlatShortcutsPanel panel = createShortcutsPanel( fc );
 			if( panel.getComponentCount() > 0 ) {
 				shortcutsPanel = panel;
-				fc.add( shortcutsPanel, BorderLayout.LINE_START );
+				shortcutsScrollPane = new JScrollPane( shortcutsPanel,
+					JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER );
+				shortcutsScrollPane.setBorder( BorderFactory.createEmptyBorder() );
+				fc.add( shortcutsScrollPane, BorderLayout.LINE_START );
 				fc.addPropertyChangeListener( shortcutsPanel );
 			}
 		}
@@ -196,6 +203,7 @@ public class FlatFileChooserUI
 		if( shortcutsPanel != null ) {
 			fc.removePropertyChangeListener( shortcutsPanel );
 			shortcutsPanel = null;
+			shortcutsScrollPane = null;
 		}
 	}
 
@@ -324,7 +332,7 @@ public class FlatFileChooserUI
 	public Dimension getPreferredSize( JComponent c ) {
 		Dimension prefSize = super.getPreferredSize( c );
 		Dimension minSize = getMinimumSize( c );
-		int shortcutsPanelWidth = (shortcutsPanel != null) ? shortcutsPanel.getPreferredSize().width : 0;
+		int shortcutsPanelWidth = (shortcutsScrollPane != null) ? shortcutsScrollPane.getPreferredSize().width : 0;
 		return new Dimension(
 			Math.max( prefSize.width, minSize.width + shortcutsPanelWidth ),
 			Math.max( prefSize.height, minSize.height ) );
@@ -368,27 +376,68 @@ public class FlatFileChooserUI
 			if( icon != null )
 				return icon;
 
-			// get system icon
-			if( f != null ) {
-				icon = getFileChooser().getFileSystemView().getSystemIcon( f );
-
-				if( icon != null ) {
-					if( icon instanceof ImageIcon )
-						icon = new ScaledImageIcon( (ImageIcon) icon );
-					cacheIcon( f, icon );
-					return icon;
+			// new proxy icon
+			//
+			// Note: Since this is a super light weight icon object, we do not add it
+			//       to the icon cache here. This keeps cache small in case of large directories
+			//       with thousands of files when icons of all files are only needed to compute
+			//       the layout of list/table, but never painted because located outside of visible area.
+			//       When an icon needs to be painted, the proxy adds it to the icon cache
+			//       and loads the real icon.
+			return new FlatFileViewIcon( f );
 		}
+
+		//---- class FlatFileViewIcon -----------------------------------------
+
+		/**
+		 * A proxy icon that has a fixed (scaled) width/height (16x16) and
+		 * gets/loads the real (system) icon only for painting.
+		 * Avoids unnecessary getting/loading system icons.
+		 */
+		private class FlatFileViewIcon
+			implements Icon
+		{
+			private final File f;
+			private Icon realIcon;
+
+			FlatFileViewIcon( File f ) {
+				this.f = f;
+			}
+
+			@Override
+			public int getIconWidth() {
+				return UIScale.scale( 16 );
+			}
+
+			@Override
+			public int getIconHeight() {
+				return UIScale.scale( 16 );
+			}
+
+			@Override
+			public void paintIcon( Component c, Graphics g, int x, int y ) {
+				// get icon on demand
+				if( realIcon == null ) {
+					// get system icon
+					try {
+						if( f != null )
+							realIcon = getFileChooser().getFileSystemView().getSystemIcon( f );
+					} catch( NullPointerException ex ) {
+						// Java 21 may throw a NPE for exe files that use default Windows exe icon
 					}
 
 					// get default icon
-			icon = super.getIcon( f );
+					if( realIcon == null )
+						realIcon = FlatFileView.super.getIcon( f );
 
-			if( icon instanceof ImageIcon ) {
-				icon = new ScaledImageIcon( (ImageIcon) icon );
-				cacheIcon( f, icon );
+					if( realIcon instanceof ImageIcon )
+						realIcon = new ScaledImageIcon( (ImageIcon) realIcon );
+
+					cacheIcon( f, this );
 				}
 
-			return icon;
+				realIcon.paintIcon( c, g, x, y );
+			}
 		}
 	}
 
@@ -397,7 +446,7 @@ public class FlatFileChooserUI
 	/** @since 2.3 */
 	public static class FlatShortcutsPanel
 		extends JToolBar
-		implements PropertyChangeListener
+		implements PropertyChangeListener, Scrollable
 	{
 		private final JFileChooser fc;
 
@@ -416,6 +465,7 @@ public class FlatFileChooserUI
 			super( JToolBar.VERTICAL );
 			this.fc = fc;
 			setFloatable( false );
+			putClientProperty( FlatClientProperties.STYLE, "hoverButtonGroupBackground: null" );
 
 			buttonSize = UIScale.scale( getUIDimension( "FileChooser.shortcuts.buttonSize", 84, 64 ) );
 			iconSize = getUIDimension( "FileChooser.shortcuts.iconSize", 32, 32 );
@@ -425,7 +475,7 @@ public class FlatFileChooserUI
 			iconFunction = (Function<File, Icon>) UIManager.get( "FileChooser.shortcuts.iconFunction" );
 
 			FileSystemView fsv = fc.getFileSystemView();
-			File[] files = getChooserShortcutPanelFiles( fsv );
+			File[] files = JavaCompatibility2.getChooserShortcutPanelFiles( fsv );
 			if( filesFunction != null )
 				files = filesFunction.apply( files );
 
@@ -457,7 +507,7 @@ public class FlatFileChooserUI
 					icon = new ShortcutIcon( icon, iconSize.width, iconSize.height );
 
 				// create button
-				JToggleButton button = createButton( name, icon );
+				JToggleButton button = createButton( name, icon, file.toString() );
 				File f = file;
 				button.addActionListener( e -> {
 					fc.setCurrentDirectory( f );
@@ -483,8 +533,10 @@ public class FlatFileChooserUI
 			return size;
 		}
 
-		protected JToggleButton createButton( String name, Icon icon ) {
+		/** @since 3.5 */
+		protected JToggleButton createButton( String name, Icon icon, String toolTip ) {
 			JToggleButton button = new JToggleButton( name, icon );
+			button.setToolTipText( toolTip );
 			button.setVerticalTextPosition( SwingConstants.BOTTOM );
 			button.setHorizontalTextPosition( SwingConstants.CENTER );
 			button.setAlignmentX( Component.CENTER_ALIGNMENT );
@@ -494,32 +546,6 @@ public class FlatFileChooserUI
 			return button;
 		}
 
-		protected File[] getChooserShortcutPanelFiles( FileSystemView fsv ) {
-			try {
-				if( SystemInfo.isJava_12_orLater ) {
-					Method m = fsv.getClass().getMethod( "getChooserShortcutPanelFiles" );
-					File[] files = (File[]) m.invoke( fsv );
-
-					// on macOS and Linux, files consists only of the user home directory
-					if( files.length == 1 && files[0].equals( new File( System.getProperty( "user.home" ) ) ) )
-						files = new File[0];
-
-					return files;
-				} else if( SystemInfo.isWindows ) {
-					Class<?> cls = Class.forName( "sun.awt.shell.ShellFolder" );
-					Method m = cls.getMethod( "get", String.class );
-					return (File[]) m.invoke( null, "fileChooserShortcutPanelFolders" );
-				}
-			} catch( IllegalAccessException ex ) {
-				// do not log because access may be denied via VM option '--illegal-access=deny'
-			} catch( Exception ex ) {
-				LoggingFacade.INSTANCE.logSevere( null, ex );
-			}
-
-			// fallback
-			return new File[0];
-		}
-
 		protected String getDisplayName( FileSystemView fsv, File file ) {
 			if( displayNameFunction != null ) {
 				String name = displayNameFunction.apply( file );
@@ -540,6 +566,7 @@ public class FlatFileChooserUI
 			if( doNotUseSystemIcons() )
 				return new FlatFileViewDirectoryIcon();
 
+			try {
 				// Java 17+ supports getting larger system icons
 				try {
 					if( SystemInfo.isJava_17_orLater ) {
@@ -565,6 +592,10 @@ public class FlatFileChooserUI
 
 				// get system icon in default size 16x16
 				return fsv.getSystemIcon( file );
+			} catch( NullPointerException ex ) {
+				// Java 21 may throw a NPE for exe files that use default Windows exe icon
+				return new FlatFileViewDirectoryIcon();
+			}
 		}
 
 		protected void directoryChanged( File file ) {
@@ -583,6 +614,8 @@ public class FlatFileChooserUI
 			buttonGroup.clearSelection();
 		}
 
+		//---- interface PropertyChangeListener ----
+
 		@Override
 		public void propertyChange( PropertyChangeEvent e ) {
 			switch( e.getPropertyName() ) {
@@ -591,6 +624,41 @@ public class FlatFileChooserUI
 					break;
 			}
 		}
+
+		//---- interface Scrollable ----
+
+		@Override
+		public Dimension getPreferredScrollableViewportSize() {
+			if( getComponentCount() > 0 ) {
+				Insets insets = getInsets();
+				int height = (getComponent( 0 ).getPreferredSize().height * 5) + insets.top + insets.bottom;
+				return new Dimension( getPreferredSize().width, height );
+			}
+			return getPreferredSize();
+		}
+
+		@Override
+		public int getScrollableUnitIncrement( Rectangle visibleRect, int orientation, int direction ) {
+			if( orientation == SwingConstants.VERTICAL && getComponentCount() > 0 )
+				return getComponent( 0 ).getPreferredSize().height;
+
+			return getScrollableBlockIncrement( visibleRect, orientation, direction ) / 10;
+		}
+
+		@Override
+		public int getScrollableBlockIncrement( Rectangle visibleRect, int orientation, int direction ) {
+			return (orientation == SwingConstants.VERTICAL) ? visibleRect.height : visibleRect.width;
+		}
+
+		@Override
+		public boolean getScrollableTracksViewportWidth() {
+			return true;
+		}
+
+		@Override
+		public boolean getScrollableTracksViewportHeight() {
+			return false;
+		}
 	}
 
 	//---- class ShortcutIcon -------------------------------------------------

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatHTML.java

@@ -0,0 +1,290 @@
+/*
+ * Copyright 2024 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.ui;
+
+import java.awt.Color;
+import java.awt.Font;
+import java.beans.PropertyChangeEvent;
+import java.beans.PropertyChangeListener;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.function.BiConsumer;
+import javax.swing.AbstractButton;
+import javax.swing.JComponent;
+import javax.swing.JLabel;
+import javax.swing.JToolTip;
+import javax.swing.plaf.basic.BasicHTML;
+import javax.swing.text.AttributeSet;
+import javax.swing.text.Document;
+import javax.swing.text.LabelView;
+import javax.swing.text.Style;
+import javax.swing.text.StyleConstants;
+import javax.swing.text.View;
+import javax.swing.text.html.CSS;
+import javax.swing.text.html.HTMLDocument;
+import javax.swing.text.html.StyleSheet;
+
+/**
+ * @author Karl Tauber
+ * @since 3.5
+ */
+public class FlatHTML
+{
+	private FlatHTML() {}
+
+	/**
+	 * Adds CSS rule BASE_SIZE to the style sheet of the HTML view,
+	 * which re-calculates font sizes based on current component font size.
+	 * This is necessary for "absolute-size" keywords (e.g. "x-large")
+	 * for "font-size" attributes in default style sheet (see javax/swing/text/html/default.css).
+	 * See also <a href="https://developer.mozilla.org/en-US/docs/Web/CSS/font-size#values">CSS font-size</a>.
+	 * <p>
+	 * This method should be invoked after {@link BasicHTML#updateRenderer(JComponent, String)}.
+	 */
+	public static void updateRendererCSSFontBaseSize( JComponent c ) {
+		View view = (View) c.getClientProperty( BasicHTML.propertyKey );
+		if( view == null )
+			return;
+
+//		dumpViews( view, 0 );
+
+		Document doc = view.getDocument();
+		if( !(doc instanceof HTMLDocument) )
+			return;
+
+		// add BASE_SIZE rule if necessary
+		//  - if point size at index 7 is not 36, then probably HTML text contains BASE_SIZE rule
+		//  - if point size at index 4 is equal to given font size, then it is not necessary to add BASE_SIZE rule
+		StyleSheet styleSheet = ((HTMLDocument)doc).getStyleSheet();
+/*debug
+		for( int i = 1; i <= 7; i++ )
+			System.out.println( i+": "+ styleSheet.getPointSize( i ) );
+debug*/
+		Font font = c.getFont();
+		if( styleSheet.getPointSize( 7 ) != 36f ||
+			font == null || styleSheet.getPointSize( 4 ) == font.getSize() )
+		  return;
+
+		// check whether view uses "absolute-size" keywords (e.g. "x-large") for font-size
+		if( !usesAbsoluteSizeKeywordForFontSize( view ) )
+			return;
+
+		// get HTML text from component
+		String text;
+		if( c instanceof JLabel )
+			text = ((JLabel)c).getText();
+		else if( c instanceof AbstractButton )
+			text = ((AbstractButton)c).getText();
+		else if( c instanceof JToolTip )
+			text = ((JToolTip)c).getTipText();
+		else
+			return;
+		if( text == null || !BasicHTML.isHTMLString( text ) )
+			return;
+
+		// BASE_SIZE rule is parsed in javax.swing.text.html.StyleSheet.addRule()
+		String style = "<style>BASE_SIZE " + font.getSize() + "</style>";
+		String openTag = "";
+		String closeTag = "";
+
+		int headIndex;
+		int styleIndex;
+
+		int insertIndex;
+		if( (headIndex = indexOfTag( text, "head", true )) >= 0 ) {
+			// there is a <head> tag --> insert after <head> tag
+			insertIndex = headIndex;
+		} else if( (styleIndex = indexOfTag( text, "style", false )) >= 0 ) {
+			// there is a <style> tag --> insert before <style> tag
+			insertIndex = styleIndex;
+		} else {
+			// no <head> or <style> tag --> insert <head> tag after <html> tag
+			insertIndex = "<html>".length();
+			openTag = "<head>";
+			closeTag = "</head>";
+		}
+
+		String newText = text.substring( 0, insertIndex )
+			+ openTag + style + closeTag
+			+ text.substring( insertIndex );
+
+		BasicHTML.updateRenderer( c, newText );
+
+		// for unit tests
+		if( testUpdateRenderer != null )
+			testUpdateRenderer.accept( c, newText );
+	}
+
+	// for unit tests
+	static BiConsumer<JComponent, String> testUpdateRenderer;
+
+	/**
+	 * Returns start or end index of a HTML tag.
+	 * Checks only for leading '<' character and (case-ignore) tag name.
+	 */
+	private static int indexOfTag( String html, String tag, boolean endIndex ) {
+		int tagLength = tag.length();
+		int maxLength = html.length() - tagLength - 2;
+		char lastTagChar = tag.charAt( tagLength - 1 );
+
+		for( int i = "<html>".length(); i < maxLength; i++ ) {
+			// check for leading '<' and last tag name character
+			if( html.charAt( i ) == '<' && Character.toLowerCase( html.charAt( i + tagLength ) ) == lastTagChar ) {
+				// compare tag characters from last to first
+				for( int j = tagLength - 2; j >= 0; j-- ) {
+					if( Character.toLowerCase( html.charAt( i + 1 + j ) ) != tag.charAt( j ) )
+						break; // not equal
+
+					if( j == 0 ) {
+						// tag found
+						return endIndex ? html.indexOf( '>', i + tagLength ) + 1 : i;
+					}
+				}
+			}
+		}
+
+		return -1;
+	}
+
+	private static final Set<String> absoluteSizeKeywordsSet = new HashSet<>( Arrays.asList(
+		"xx-small", "x-small", "small", "medium", "large", "x-large", "xx-large" ) );
+
+	/**
+	 * Checks whether view uses "absolute-size" keywords (e.g. "x-large") for font-size
+	 * (see javax/swing/text/html/default.css).
+	 */
+	private static boolean usesAbsoluteSizeKeywordForFontSize( View view ) {
+		AttributeSet attributes = view.getAttributes();
+		if( attributes != null ) {
+			Object fontSize = attributes.getAttribute( CSS.Attribute.FONT_SIZE );
+			if( fontSize != null ) {
+				if( absoluteSizeKeywordsSet.contains( fontSize.toString() ) )
+					return true;
+			}
+		}
+
+		int viewCount = view.getViewCount();
+		for( int i = 0; i < viewCount; i++ ) {
+			if( usesAbsoluteSizeKeywordForFontSize( view.getView( i ) ) )
+				return true;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Updates foreground in style sheet of the HTML view.
+	 * Adds "body { color: #&lt;foreground-hex&gt;; }"
+	 */
+	public static void updateRendererCSSForeground( View view, Color foreground ) {
+		Document doc = view.getDocument();
+		if( !(doc instanceof HTMLDocument) || foreground == null )
+			return;
+
+		// add foreground rule if necessary
+		//  - use tag 'body' because BasicHTML.createHTMLView() also uses this tag
+		//    to set font and color styles to component font/color
+		//    see: SwingUtilities2.displayPropertiesToCSS()
+		//  - this color is not used if component is disabled;
+		//    JTextComponent.getDisabledTextColor() is used for disabled text components;
+		//    UIManager.getColor("textInactiveText") is used for other disabled components
+		//    see: javax.swing.text.GlyphView.paint()
+		Style bodyStyle = ((HTMLDocument)doc).getStyle( "body" );
+		if( bodyStyle == null ) {
+			StyleSheet styleSheet = ((HTMLDocument)doc).getStyleSheet();
+			styleSheet.addRule( String.format( "body { color: #%06x; }", foreground.getRGB() & 0xffffff ) );
+			clearViewCaches( view );
+		} else if( !foreground.equals( bodyStyle.getAttribute( StyleConstants.Foreground ) ) ) {
+			bodyStyle.addAttribute( StyleConstants.Foreground, foreground );
+			clearViewCaches( view );
+		}
+	}
+
+	/**
+	 * Clears cached values in view so that CSS changes take effect.
+	 */
+	private static void clearViewCaches( View view ) {
+		if( view instanceof LabelView )
+			((LabelView)view).changedUpdate( null, null, null );
+
+		int viewCount = view.getViewCount();
+		for( int i = 0; i < viewCount; i++ )
+			clearViewCaches( view.getView( i ) );
+	}
+
+	public static PropertyChangeListener createPropertyChangeListener( PropertyChangeListener superListener ) {
+		return e -> {
+			if( superListener != null )
+				superListener.propertyChange( e );
+			propertyChange( e );
+		};
+	}
+
+	/**
+	 * Invokes {@link #updateRendererCSSFontBaseSize(JComponent)}
+	 * for {@link BasicHTML#propertyKey} property change events,
+	 * which are fired when {@link BasicHTML#updateRenderer(JComponent, String)}
+	 * updates the HTML view.
+	 */
+	public static void propertyChange( PropertyChangeEvent e ) {
+		if( BasicHTML.propertyKey.equals( e.getPropertyName() ) && e.getNewValue() instanceof View )
+			updateRendererCSSFontBaseSize( (JComponent) e.getSource() );
+	}
+
+/*debug
+	public static void dumpView( JComponent c ) {
+		View view = (View) c.getClientProperty( BasicHTML.propertyKey );
+		if( view != null )
+			dumpViews( view, 0 );
+	}
+
+	public static void dumpViews( View view, int indent ) {
+		for( int i = 0; i < indent; i++ )
+			System.out.print( "    " );
+
+		System.out.printf( "%s @%-8x   %3d,%2d",
+			view.getClass().isAnonymousClass() ? view.getClass().getName() : view.getClass().getSimpleName(),
+			System.identityHashCode( view ),
+			(int) view.getPreferredSpan( View.X_AXIS ),
+			(int) view.getPreferredSpan( View.Y_AXIS ) );
+
+		AttributeSet attrs = view.getAttributes();
+		if( attrs != null ) {
+			Object fontSize = attrs.getAttribute( CSS.Attribute.FONT_SIZE );
+			System.out.printf( "  %-8s", fontSize );
+		}
+
+		if( view instanceof javax.swing.text.GlyphView ) {
+			javax.swing.text.GlyphView gview = ((javax.swing.text.GlyphView)view);
+			java.awt.Font font = gview.getFont();
+			System.out.printf( "   %3d-%-3d  %s %2d (@%x)  #%06x  '%s'",
+				gview.getStartOffset(), gview.getEndOffset() - 1,
+				font.getName(), font.getSize(), System.identityHashCode( font ),
+				gview.getForeground().getRGB() & 0xffffff,
+				gview.getText( gview.getStartOffset(), gview.getEndOffset() ) );
+		}
+		System.out.println();
+
+		int viewCount = view.getViewCount();
+		for( int i = 0; i < viewCount; i++ ) {
+			View child = view.getView( i );
+			dumpViews( child, indent + 1 );
+		}
+	}
+debug*/
+}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatLabelUI.java

@@ -22,11 +22,7 @@ import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.Rectangle;
 import java.beans.PropertyChangeEvent;
-import java.util.Arrays;
-import java.util.HashSet;
-import java.util.Locale;
 import java.util.Map;
-import java.util.Set;
 import javax.swing.Icon;
 import javax.swing.JComponent;
 import javax.swing.JLabel;
@@ -64,6 +60,9 @@ public class FlatLabelUI
 {
 	@Styleable protected Color disabledForeground;
 
+	// only used via styling (not in UI defaults)
+	/** @since 3.5 */ @Styleable protected int arc = -1;
+
 	private final boolean shared;
 	private boolean defaults_initialized = false;
 	private Map<String, Object> oldStyleValues;
@@ -110,16 +109,13 @@ public class FlatLabelUI
 		super.installComponents( c );
 
 		// update HTML renderer if necessary
-		updateHTMLRenderer( c, c.getText(), false );
+		FlatHTML.updateRendererCSSFontBaseSize( c );
 	}
 
 	@Override
 	public void propertyChange( PropertyChangeEvent e ) {
 		String name = e.getPropertyName();
-		if( name == "text" || name == "font" || name == "foreground" ) {
-			JLabel label = (JLabel) e.getSource();
-			updateHTMLRenderer( label, label.getText(), true );
-		} else if( name.equals( FlatClientProperties.STYLE ) || name.equals( FlatClientProperties.STYLE_CLASS ) ) {
+		if( name.equals( FlatClientProperties.STYLE ) || name.equals( FlatClientProperties.STYLE_CLASS ) ) {
 			JLabel label = (JLabel) e.getSource();
 			if( shared && FlatStylingSupport.hasStyleProperty( label ) ) {
 				// unshare component UI if necessary
@@ -128,9 +124,11 @@ public class FlatLabelUI
 			} else
 				installStyle( label );
 			label.revalidate();
-			label.repaint();
-		} else
+			HiDPIUtils.repaint( label );
+		}
+
 		super.propertyChange( e );
+		FlatHTML.propertyChange( e );
 	}
 
 	/** @since 2 */
@@ -165,83 +163,10 @@ public class FlatLabelUI
 		return FlatStylingSupport.getAnnotatedStyleableValue( this, key );
 	}
 
-	/**
-	 * Checks whether text contains HTML tags that use "absolute-size" keywords
-	 * (e.g. "x-large") for font-size in default style sheet
-	 * (see javax/swing/text/html/default.css).
-	 * If yes, adds a special CSS rule (BASE_SIZE) to the HTML text, which
-	 * re-calculates font sizes based on current component font size.
-	 */
-	static void updateHTMLRenderer( JComponent c, String text, boolean always ) {
-		if( BasicHTML.isHTMLString( text ) &&
-			c.getClientProperty( "html.disable" ) != Boolean.TRUE &&
-			needsFontBaseSize( text ) )
-		{
-			// BASE_SIZE rule is parsed in javax.swing.text.html.StyleSheet.addRule()
-			String style = "<style>BASE_SIZE " + c.getFont().getSize() + "</style>";
-
-			String lowerText = text.toLowerCase( Locale.ENGLISH );
-			int headIndex;
-			int styleIndex;
-
-			int insertIndex;
-			if( (headIndex = lowerText.indexOf( "<head>" )) >= 0 ) {
-				// there is a <head> tag --> insert after <head> tag
-				insertIndex = headIndex + "<head>".length();
-			} else if( (styleIndex = lowerText.indexOf( "<style>" )) >= 0 ) {
-				// there is a <style> tag --> insert before <style> tag
-				insertIndex = styleIndex;
-			} else {
-				// no <head> or <style> tag --> insert <head> tag after <html> tag
-				style = "<head>" + style + "</head>";
-				insertIndex = "<html>".length();
-			}
-
-			text = text.substring( 0, insertIndex )
-				+ style
-				+ text.substring( insertIndex );
-		} else if( !always )
-			return; // not necessary to invoke BasicHTML.updateRenderer()
-
-		BasicHTML.updateRenderer( c, text );
-	}
-
-	private static Set<String> tagsUseFontSizeSet;
-
-	private static boolean needsFontBaseSize( String text ) {
-		if( tagsUseFontSizeSet == null ) {
-			// tags that use font-size in javax/swing/text/html/default.css
-			tagsUseFontSizeSet = new HashSet<>( Arrays.asList(
-				"h1", "h2", "h3", "h4", "h5", "h6", "code", "kbd", "big", "small", "samp" ) );
-		}
-
-		// search for tags in HTML text
-		int textLength = text.length();
-		for( int i = 6; i < textLength - 1; i++ ) {
-			if( text.charAt( i ) == '<' ) {
-				switch( text.charAt( i + 1 ) ) {
-					// first letters of tags in tagsUseFontSizeSet
-					case 'b': case 'B':
-					case 'c': case 'C':
-					case 'h': case 'H':
-					case 'k': case 'K':
-					case 's': case 'S':
-						int tagBegin = i + 1;
-						for( i += 2; i < textLength; i++ ) {
-							if( !Character.isLetterOrDigit( text.charAt( i ) ) ) {
-								String tag = text.substring( tagBegin, i ).toLowerCase( Locale.ENGLISH );
-								if( tagsUseFontSizeSet.contains( tag ) )
-									return true;
-
-								break;
-							}
-						}
-						break;
-				}
-			}
-		}
-
-		return false;
+	@Override
+	public void update( Graphics g, JComponent c ) {
+		FlatPanelUI.fillRoundedBackground( g, c, arc );
+		paint( g, c );
 	}
 
 	static Graphics createGraphicsHTMLTextYCorrection( Graphics g, JComponent c ) {

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatLineBorder.java

@@ -22,13 +22,21 @@ import java.awt.Component;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.Insets;
+import javax.swing.JComponent;
+import javax.swing.JLabel;
+import javax.swing.JPanel;
+import javax.swing.plaf.ComponentUI;
 
 /**
  * Line border for various components.
- *
+ * <p>
  * Paints a scaled (usually 1px thick) line around the component.
  * The line thickness is not added to the border insets.
  * The insets should be at least have line thickness (usually 1,1,1,1).
+ * <p>
+ * For {@link javax.swing.JPanel} and {@link javax.swing.JLabel}, this border
+ * can be used paint rounded background (if line color is {@code null}) or
+ * paint rounded line border with rounded background.
  *
  * @author Karl Tauber
  */
@@ -40,7 +48,7 @@ public class FlatLineBorder
 	/** @since 2 */ private final int arc;
 
 	public FlatLineBorder( Insets insets, Color lineColor ) {
-		this( insets, lineColor, 1f, 0 );
+		this( insets, lineColor, 1f, -1 );
 	}
 
 	/** @since 2 */
@@ -51,26 +59,62 @@ public class FlatLineBorder
 		this.arc = arc;
 	}
 
+	/** @since 3.5 */
+	public FlatLineBorder( Insets insets, int arc ) {
+		this( insets, null, 0, arc );
+	}
+
 	public Color getLineColor() {
 		return lineColor;
 	}
 
+	/**
+	 * Returns the (unscaled) line thickness used to paint the border.
+	 * The line thickness does not affect the border insets.
+	 */
 	public float getLineThickness() {
 		return lineThickness;
 	}
 
-	/** @since 2 */
+	/**
+	 * Returns the (unscaled) arc diameter of the border corners.
+	 *
+	 * @since 2
+	 */
 	public int getArc() {
 		return arc;
 	}
 
 	@Override
 	public void paintBorder( Component c, Graphics g, int x, int y, int width, int height ) {
+		if( c instanceof JComponent && ((JComponent)c).getClientProperty( FlatPopupFactory.KEY_POPUP_USES_NATIVE_BORDER ) != null )
+			return;
+
+		Color lineColor = getLineColor();
+		float lineThickness = getLineThickness();
+		if( lineColor == null || lineThickness <= 0 )
+			return;
+
+		int arc = getArc();
+		if( arc < 0 ) {
+			// get arc from label or panel
+			ComponentUI ui = (c instanceof JLabel)
+				? ((JLabel)c).getUI()
+				: (c instanceof JPanel ? ((JPanel)c).getUI() : null);
+			if( ui instanceof FlatLabelUI )
+				arc = ((FlatLabelUI)ui).arc;
+			else if( ui instanceof FlatPanelUI )
+				arc = ((FlatPanelUI)ui).arc;
+
+			if( arc < 0 )
+				arc = 0;
+		}
+
 		Graphics2D g2 = (Graphics2D) g.create();
 		try {
 			FlatUIUtils.setRenderingHints( g2 );
 			FlatUIUtils.paintOutlinedComponent( g2, x, y, width, height,
-				0, 0, 0, scale( getLineThickness() ), scale( getArc() ), null, getLineColor(), null );
+				0, 0, 0, scale( lineThickness ), scale( arc ), null, lineColor, null );
 		} finally {
 			g2.dispose();
 		}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatListUI.java

@@ -43,6 +43,7 @@ import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
 import com.formdev.flatlaf.util.Graphics2DProxy;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.UIScale;
 
@@ -56,6 +57,7 @@ import com.formdev.flatlaf.util.UIScale;
  * @uiDefault List.foreground						Color
  * @uiDefault List.selectionBackground				Color
  * @uiDefault List.selectionForeground				Color
+ * @uiDefault List.alternateRowColor				Color
  * @uiDefault List.dropLineColor					Color
  * @uiDefault List.border							Border
  * @uiDefault List.cellRenderer						ListCellRenderer
@@ -92,6 +94,7 @@ public class FlatListUI
 	@Styleable protected Color selectionForeground;
 	@Styleable protected Color selectionInactiveBackground;
 	@Styleable protected Color selectionInactiveForeground;
+	/** @since 3.6 */ @Styleable protected Color alternateRowColor;
 	/** @since 3 */ @Styleable protected Insets selectionInsets;
 	/** @since 3 */ @Styleable protected int selectionArc;
 
@@ -128,6 +131,7 @@ public class FlatListUI
 		selectionForeground = UIManager.getColor( "List.selectionForeground" );
 		selectionInactiveBackground = UIManager.getColor( "List.selectionInactiveBackground" );
 		selectionInactiveForeground = UIManager.getColor( "List.selectionInactiveForeground" );
+		alternateRowColor = UIManager.getColor( "List.alternateRowColor" );
 		selectionInsets = UIManager.getInsets( "List.selectionInsets" );
 		selectionArc = UIManager.getInt( "List.selectionArc" );
 
@@ -142,6 +146,7 @@ public class FlatListUI
 		selectionForeground = null;
 		selectionInactiveBackground = null;
 		selectionInactiveForeground = null;
+		alternateRowColor = null;
 
 		oldStyleValues = null;
 	}
@@ -182,7 +187,7 @@ public class FlatListUI
 				case FlatClientProperties.STYLE_CLASS:
 					installStyle();
 					list.revalidate();
-					list.repaint();
+					HiDPIUtils.repaint( list );
 					break;
 			}
 		};
@@ -205,7 +210,7 @@ public class FlatListUI
 				Rectangle r = getCellBounds( list, firstIndex, lastIndex );
 				if( r != null ) {
 					int arc = (int) Math.ceil( UIScale.scale( selectionArc / 2f ) );
-					list.repaint( r.x - arc, r.y - arc, r.width + (arc * 2), r.height + (arc * 2) );
+					HiDPIUtils.repaint( list, r.x - arc, r.y - arc, r.width + (arc * 2), r.height + (arc * 2) );
 				}
 			}
 		};
@@ -297,6 +302,18 @@ public class FlatListUI
 		ListModel dataModel, ListSelectionModel selModel, int leadIndex )
 	{
 		boolean isSelected = selModel.isSelectedIndex( row );
+		boolean isDropRow = isDropRow( row );
+
+		// paint alternating rows
+		if( alternateRowColor != null && row % 2 != 0 &&
+			!"ComboBox.list".equals( list.getName() ) ) // combobox does not support alternate row color
+		{
+			g.setColor( alternateRowColor );
+
+			float arc = UIScale.scale( selectionArc / 2f );
+			FlatUIUtils.paintSelection( (Graphics2D) g, rowBounds.x, rowBounds.y, rowBounds.width, rowBounds.height,
+				UIScale.scale( selectionInsets ), arc, arc, arc, arc, 0 );
+		}
 
 		// get renderer component
 		@SuppressWarnings( "unchecked" )
@@ -304,7 +321,7 @@ public class FlatListUI
 			dataModel.getElementAt( row ), row, isSelected,
 			FlatUIUtils.isPermanentFocusOwner( list ) && (row == leadIndex) );
 
-		//
+		// use smaller cell width if list is used in JFileChooser
 		boolean isFileList = Boolean.TRUE.equals( list.getClientProperty( "List.isFileList" ) );
 		int cx, cw;
 		if( isFileList ) {
@@ -319,13 +336,12 @@ public class FlatListUI
 		}
 
 		// rounded selection or selection insets
-		if( isSelected &&
+		if( (isSelected || isDropRow) &&
 			!isFileList && // rounded selection is not supported for file list
 			(rendererComponent instanceof DefaultListCellRenderer ||
 			 rendererComponent instanceof BasicComboBoxRenderer) &&
 			(selectionArc > 0 ||
-			 (selectionInsets != null &&
-			  (selectionInsets.top != 0 || selectionInsets.left != 0 || selectionInsets.bottom != 0 || selectionInsets.right != 0))) )
+			 (selectionInsets != null && !FlatUIUtils.isInsetsEmpty( selectionInsets ))) )
 		{
 			// Because selection painting is done in the cell renderer, it would be
 			// necessary to require a FlatLaf specific renderer to implement rounded selection.
@@ -361,6 +377,21 @@ public class FlatListUI
 						this.getColor() == rendererComponent.getBackground() )
 					{
 						inPaintSelection = true;
+						if( isDropRow ) {
+							// for rounded drop background, it is necessary to first
+							// paint selection background because may be not rounded on some corners
+							if( isSelected ) {
+								Color oldColor = getColor();
+								setColor( list.getSelectionBackground() );
+								paintCellSelection( this, row, x, y, width, height );
+								setColor( oldColor );
+							}
+
+							// paint drop background
+							float arc = UIScale.scale( selectionArc / 2f );
+							FlatUIUtils.paintSelection( this, x, y, width, height,
+								UIScale.scale( selectionInsets ), arc, arc, arc, arc, 0 );
+						} else
 							paintCellSelection( this, row, x, y, width, height );
 						inPaintSelection = false;
 					} else
@@ -374,7 +405,15 @@ public class FlatListUI
 		rendererPane.paintComponent( g, rendererComponent, list, cx, rowBounds.y, cw, rowBounds.height, true );
 	}
 
-	/** @since 3 */
+	/**
+	 * Paints (rounded) cell selection.
+	 * Supports {@link #selectionArc} and {@link #selectionInsets}.
+	 * <p>
+	 * <b>Note:</b> This method is only invoked if either selection arc
+	 *              is greater than zero or if selection insets are not empty.
+	 *
+	 * @since 3
+	 */
 	protected void paintCellSelection( Graphics g, int row, int x, int y, int width, int height ) {
 		float arcTopLeft, arcTopRight, arcBottomLeft, arcBottomRight;
 		arcTopLeft = arcTopRight = arcBottomLeft = arcBottomRight = UIScale.scale( selectionArc / 2f );
@@ -411,7 +450,7 @@ public class FlatListUI
 				int leftIndex = locationToIndex( list, new Point( r.x - 1, r.y ) );
 				int rightIndex = locationToIndex( list, new Point( r.x + r.width, r.y ) );
 
-				// special handling for the case that last column contains less cells than the other columns
+				// special handling for the case that last column contains fewer cells than the other columns
 				boolean ltr = list.getComponentOrientation().isLeftToRight();
 				if( !ltr && leftIndex >= 0 && leftIndex != row && leftIndex == locationToIndex( list, new Point( r.x - 1, r.y - 1 ) ) )
 					leftIndex = -1;
@@ -440,7 +479,8 @@ public class FlatListUI
 	 * Paints a cell selection at the given coordinates.
 	 * The selection color must be set on the graphics context.
 	 * <p>
-	 * This method is intended for use in custom cell renderers.
+	 * This method is intended for use in custom cell renderers
+	 * to support {@link #selectionArc} and {@link #selectionInsets}.
 	 *
 	 * @since 3
 	 */
@@ -451,4 +491,15 @@ public class FlatListUI
 		FlatListUI ui = (FlatListUI) list.getUI();
 		ui.paintCellSelection( g, row, x, y, width, height );
 	}
+
+	/**
+	 * Checks whether dropping on a row.
+	 * See DefaultListCellRenderer.getListCellRendererComponent().
+	 */
+	private boolean isDropRow( int row ) {
+		JList.DropLocation dropLocation = list.getDropLocation();
+		return dropLocation != null &&
+			!dropLocation.isInsert() &&
+			dropLocation.getIndex() == row;
+	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuBarUI.java

@@ -27,7 +27,6 @@ import java.awt.event.ActionEvent;
 import java.beans.PropertyChangeListener;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicBoolean;
-import javax.swing.AbstractAction;
 import javax.swing.ActionMap;
 import javax.swing.BoxLayout;
 import javax.swing.JComponent;
@@ -39,7 +38,6 @@ import javax.swing.MenuElement;
 import javax.swing.MenuSelectionManager;
 import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
-import javax.swing.plaf.ActionMapUIResource;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.UIResource;
 import javax.swing.plaf.basic.BasicMenuBarUI;
@@ -144,12 +142,10 @@ public class FlatMenuBarUI
 	protected void installKeyboardActions() {
 		super.installKeyboardActions();
 
+		// get shared action map, used for all menu bars
 		ActionMap map = SwingUtilities.getUIActionMap( menuBar );
-		if( map == null ) {
-			map = new ActionMapUIResource();
-			SwingUtilities.replaceUIActionMap( menuBar, map );
-		}
-		map.put( "takeFocus", new TakeFocus() );
+		if( map != null && !(map.get( "takeFocus" ) instanceof TakeFocusAction) )
+			map.put( "takeFocus", new TakeFocusAction( "takeFocus" ) );
 	}
 
 	/** @since 2 */
@@ -365,16 +361,20 @@ public class FlatMenuBarUI
 		}
 	}
 
-	//---- class TakeFocus ----------------------------------------------------
+	//---- class TakeFocusAction ----------------------------------------------
 
 	/**
 	 * Activates the menu bar and shows mnemonics.
 	 * On Windows, the popup of the first menu is not shown.
 	 * On other platforms, the popup of the first menu is shown.
 	 */
-	private static class TakeFocus
-		extends AbstractAction
+	private static class TakeFocusAction
+		extends FlatUIAction
 	{
+		TakeFocusAction( String name ) {
+			super( name );
+		}
+
 		@Override
 		public void actionPerformed( ActionEvent e ) {
 			JMenuBar menuBar = (JMenuBar) e.getSource();

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuItemRenderer.java

@@ -25,7 +25,9 @@ import java.awt.Font;
 import java.awt.FontMetrics;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
+import java.awt.GridLayout;
 import java.awt.Insets;
+import java.awt.LayoutManager;
 import java.awt.Paint;
 import java.awt.Rectangle;
 import java.awt.event.InputEvent;
@@ -35,6 +37,7 @@ import java.util.Map;
 import javax.swing.Icon;
 import javax.swing.JComponent;
 import javax.swing.JMenu;
+import javax.swing.JMenuBar;
 import javax.swing.JMenuItem;
 import javax.swing.KeyStroke;
 import javax.swing.SwingUtilities;
@@ -222,7 +225,7 @@ public class FlatMenuItemRenderer
 		}
 
 		// arrow size
-		if( !isTopLevelMenu && arrowIcon != null ) {
+		if( arrowIcon != null && (!isTopLevelMenu || isInVerticalMenuBar( menuItem )) ) {
 			// gap between text and arrow
 			if( accelText == null )
 				width += scale( textNoAcceleratorGap );
@@ -254,7 +257,8 @@ public class FlatMenuItemRenderer
 		boolean isTopLevelMenu = isTopLevelMenu( menuItem );
 
 		// layout arrow
-		if( !isTopLevelMenu && arrowIcon != null ) {
+		boolean showArrowIcon = (arrowIcon != null && (!isTopLevelMenu || isInVerticalMenuBar( menuItem )));
+		if( showArrowIcon ) {
 			arrowRect.width = arrowIcon.getIconWidth();
 			arrowRect.height = arrowIcon.getIconHeight();
 		} else
@@ -288,7 +292,7 @@ public class FlatMenuItemRenderer
 		int accelArrowWidth = accelRect.width + arrowRect.width;
 		if( accelText != null )
 			accelArrowWidth += scale( !isTopLevelMenu ? textAcceleratorGap : menuItem.getIconTextGap() );
-		if( !isTopLevelMenu && arrowIcon != null ) {
+		if( showArrowIcon ) {
 			if( accelText == null )
 				accelArrowWidth += scale( textNoAcceleratorGap );
 			accelArrowWidth += scale( acceleratorArrowGap );
@@ -355,7 +359,7 @@ debug*/
 		paintIcon( g, iconRect, getIconForPainting(), underlineSelection ? underlineSelectionCheckBackground : checkBackground, selectionBackground );
 		paintText( g, textRect, menuItem.getText(), selectionForeground, disabledForeground );
 		paintAccelerator( g, accelRect, getAcceleratorText(), acceleratorForeground, acceleratorSelectionForeground, disabledForeground );
-		if( !isTopLevelMenu( menuItem ) )
+		if( arrowIcon != null && (!isTopLevelMenu( menuItem ) || isInVerticalMenuBar( menuItem )) )
 			paintArrowIcon( g, arrowRect, arrowIcon );
 	}
 
@@ -520,6 +524,15 @@ debug*/
 		return menuItem instanceof JMenu && ((JMenu)menuItem).isTopLevelMenu();
 	}
 
+	/** @since 3.5 */
+	public static boolean isInVerticalMenuBar( JMenuItem menuItem ) {
+		if( !(menuItem instanceof JMenu) || !(menuItem.getParent() instanceof JMenuBar) )
+			return false;
+
+		LayoutManager layout = menuItem.getParent().getLayout();
+		return layout instanceof GridLayout && ((GridLayout)layout).getRows() != 1;
+	}
+
 	protected boolean isUnderlineSelection() {
 		return "underline".equals( UIManager.getString( "MenuItem.selectionType" ) );
 	}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuItemUI.java

@@ -103,13 +103,23 @@ public class FlatMenuItemUI
 		oldStyleValues = null;
 	}
 
+	@Override
+	protected void installComponents( JMenuItem menuItem ) {
+		super.installComponents( menuItem );
+
+		// update HTML renderer if necessary
+		FlatHTML.updateRendererCSSFontBaseSize( menuItem );
+	}
+
 	protected FlatMenuItemRenderer createRenderer() {
 		return new FlatMenuItemRenderer( menuItem, checkIcon, arrowIcon, acceleratorFont, acceleratorDelimiter );
 	}
 
 	@Override
 	protected PropertyChangeListener createPropertyChangeListener( JComponent c ) {
-		return FlatStylingSupport.createPropertyChangeListener( c, this::installStyle, super.createPropertyChangeListener( c ) );
+		return FlatHTML.createPropertyChangeListener(
+			FlatStylingSupport.createPropertyChangeListener( c, this::installStyle,
+				super.createPropertyChangeListener( c ) ) );
 	}
 
 	/** @since 2 */

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuUI.java

@@ -17,6 +17,7 @@
 package com.formdev.flatlaf.ui;
 
 import java.awt.Color;
+import java.awt.Container;
 import java.awt.Dimension;
 import java.awt.Font;
 import java.awt.Graphics;
@@ -46,6 +47,7 @@ import javax.swing.plaf.basic.BasicMenuUI;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableField;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableLookupProvider;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
 
 /**
@@ -135,6 +137,14 @@ public class FlatMenuUI
 		oldStyleValues = null;
 	}
 
+	@Override
+	protected void installComponents( JMenuItem menuItem ) {
+		super.installComponents( menuItem );
+
+		// update HTML renderer if necessary
+		FlatHTML.updateRendererCSSFontBaseSize( menuItem );
+	}
+
 	protected FlatMenuItemRenderer createRenderer() {
 		return new FlatMenuRenderer( menuItem, checkIcon, arrowIcon, acceleratorFont, acceleratorDelimiter );
 	}
@@ -158,7 +168,7 @@ public class FlatMenuUI
 				JMenu menu = (JMenu) e.getSource();
 				if( menu.isTopLevelMenu() && menu.isRolloverEnabled() ) {
 					menu.getModel().setRollover( rollover );
-					menu.repaint();
+					HiDPIUtils.repaint( menu );
 				}
 			}
 		};
@@ -166,7 +176,9 @@ public class FlatMenuUI
 
 	@Override
 	protected PropertyChangeListener createPropertyChangeListener( JComponent c ) {
-		return FlatStylingSupport.createPropertyChangeListener( c, this::installStyle, super.createPropertyChangeListener( c ) );
+		return FlatHTML.createPropertyChangeListener(
+			FlatStylingSupport.createPropertyChangeListener( c, this::installStyle,
+				super.createPropertyChangeListener( c ) ) );
 	}
 
 	/** @since 2 */
@@ -271,7 +283,7 @@ public class FlatMenuUI
 				if( !isHover() )
 					selectionBackground = getStyleFromMenuBarUI( ui -> ui.selectionBackground, menuBarSelectionBackground, selectionBackground );
 
-				JMenuBar menuBar = (JMenuBar) menuItem.getParent();
+				Container menuBar = menuItem.getParent();
 				JRootPane rootPane = SwingUtilities.getRootPane( menuBar );
 				if( rootPane != null && rootPane.getParent() instanceof Window &&
 					rootPane.getJMenuBar() == menuBar &&
@@ -321,12 +333,17 @@ public class FlatMenuUI
 		}
 
 		private <T> T getStyleFromMenuBarUI( Function<FlatMenuBarUI, T> f, T defaultValue ) {
-			MenuBarUI ui = ((JMenuBar)menuItem.getParent()).getUI();
-			if( !(ui instanceof FlatMenuBarUI) )
-				return defaultValue;
-
+			Container menuItemParent = menuItem.getParent();
+			if( menuItemParent instanceof JMenuBar ) {
+				MenuBarUI ui = ((JMenuBar) menuItemParent).getUI();
+				if( ui instanceof FlatMenuBarUI ) {
 					T value = f.apply( (FlatMenuBarUI) ui );
-			return (value != null) ? value : defaultValue;
+					if( value != null ) {
+						return value;
+					}
+				}
+			}
+			return defaultValue;
 		}
 	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatNativeLibrary.java

@@ -22,6 +22,7 @@ import java.security.CodeSource;
 import com.formdev.flatlaf.FlatSystemProperties;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.NativeLibrary;
+import com.formdev.flatlaf.util.StringUtils;
 import com.formdev.flatlaf.util.SystemInfo;
 
 /**
@@ -36,16 +37,18 @@ class FlatNativeLibrary
 	private static boolean initialized;
 	private static NativeLibrary nativeLibrary;
 
+	private native static int getApiVersion();
+
 	/**
 	 * Loads native library (if available) and returns whether loaded successfully.
 	 * Returns {@code false} if no native library is available.
 	 */
-	static synchronized boolean isLoaded() {
-		initialize();
+	static synchronized boolean isLoaded( int apiVersion ) {
+		initialize( apiVersion );
 		return (nativeLibrary != null) ? nativeLibrary.isLoaded() : false;
 	}
 
-	private static void initialize() {
+	private static void initialize( int apiVersion ) {
 		if( initialized )
 			return;
 		initialized = true;
@@ -55,6 +58,7 @@ class FlatNativeLibrary
 
 		String classifier;
 		String ext;
+		boolean unknownArch = false;
 		if( SystemInfo.isWindows_10_orLater && (SystemInfo.isX86 || SystemInfo.isX86_64 || SystemInfo.isAARCH64) ) {
 			// Windows: requires Windows 10/11 (x86, x86_64 or aarch64)
 
@@ -78,14 +82,23 @@ class FlatNativeLibrary
 			//
 			// To avoid this, flatlaf.dll is not linked to jawt.dll,
 			// which avoids loading jawt.dll when flatlaf.dll is loaded.
-			// Instead flatlaf.dll dynamically loads jawt.dll when first used,
+			// Instead, flatlaf.dll dynamically loads jawt.dll when first used,
 			// which is guaranteed after AWT initialization.
 
-		} else if( SystemInfo.isLinux && SystemInfo.isX86_64 ) {
-			// Linux: requires x86_64
+		} else if( SystemInfo.isMacOS_10_14_Mojave_orLater && (SystemInfo.isAARCH64 || SystemInfo.isX86_64) ) {
+			// macOS: requires macOS 10.14 or later (arm64 or x86_64)
 
-			classifier = "linux-x86_64";
+			classifier = SystemInfo.isAARCH64 ? "macos-arm64" : "macos-x86_64";
+			ext = "dylib";
+
+		} else if( SystemInfo.isLinux ) {
+			// Linux: x86_64 or aarch64 (but also supports unknown architectures)
+
+			classifier = SystemInfo.isAARCH64 ? "linux-arm64"
+				: (SystemInfo.isX86_64 ? "linux-x86_64"
+					: "linux-" + sanitize( System.getProperty( "os.arch" ) ));
 			ext = "so";
+			unknownArch = !SystemInfo.isX86_64 && !SystemInfo.isAARCH64;
 
 			// Load libjawt.so (part of JRE) explicitly because it is not found
 			// in all Java versions/distributions.
@@ -97,10 +110,29 @@ class FlatNativeLibrary
 			return; // no native library available for current OS or CPU architecture
 
 		// load native library
-		nativeLibrary = createNativeLibrary( classifier, ext );
+		NativeLibrary nativeLibrary = createNativeLibrary( classifier, ext, unknownArch );
+		if( !nativeLibrary.isLoaded() )
+			return;
+
+		// check API version (and check whether library works)
+		try {
+			int actualApiVersion = getApiVersion();
+			if( actualApiVersion != apiVersion ) {
+				LoggingFacade.INSTANCE.logSevere( "FlatLaf: Wrong API version in native library (expected "
+					+ apiVersion + ", actual " + actualApiVersion + "). Ignoring native library.", null );
+				return;
+			}
+		} catch( Throwable ex ) {
+			// could be a UnsatisfiedLinkError in case that loading native library
+			// from temp directory was blocked by some OS security mechanism
+			LoggingFacade.INSTANCE.logSevere( "FlatLaf: Failed to get API version of native library. Ignoring native library.", ex );
+			return;
 		}
 
-	private static NativeLibrary createNativeLibrary( String classifier, String ext ) {
+		FlatNativeLibrary.nativeLibrary = nativeLibrary;
+	}
+
+	private static NativeLibrary createNativeLibrary( String classifier, String ext, boolean unknownArch ) {
 		String libraryName = "flatlaf-" + classifier;
 
 		// load from "java.library.path" or from path specified in system property "flatlaf.nativeLibraryPath"
@@ -111,13 +143,36 @@ class FlatNativeLibrary
 				if( library.isLoaded() )
 					return library;
 
-				LoggingFacade.INSTANCE.logSevere( "Did not find library " + libraryName + " in java.library.path, using extracted library instead", null );
+				if( !unknownArch ) {
+					LoggingFacade.INSTANCE.logSevere( "FlatLaf: Native library '" + System.mapLibraryName( libraryName )
+						+ "' not found in java.library.path '" + System.getProperty( "java.library.path" )
+						+ "'. Using extracted native library instead.", null );
+				}
 			} else {
+				// try standard library naming scheme
+				// (same as in flatlaf.jar in package 'com/formdev/flatlaf/natives')
 				File libraryFile = new File( libraryPath, System.mapLibraryName( libraryName ) );
 				if( libraryFile.exists() )
 					return new NativeLibrary( libraryFile, true );
 
-				LoggingFacade.INSTANCE.logSevere( "Did not find external library " + libraryFile + ", using extracted library instead", null );
+				// try Maven naming scheme
+				// (see https://www.formdev.com/flatlaf/native-libraries/)
+				String libraryName2 = null;
+				File jarFile = getJarFile();
+				if( jarFile != null ) {
+					libraryName2 = buildLibraryName( jarFile, classifier, ext );
+					File libraryFile2 = new File( libraryPath, libraryName2 );
+					if( libraryFile2.exists() )
+						return new NativeLibrary( libraryFile2, true );
+				}
+
+				if( !unknownArch ) {
+					LoggingFacade.INSTANCE.logSevere( "FlatLaf: Native library '"
+						+ libraryFile.getName()
+						+ (libraryName2 != null ? ("' or '" + libraryName2) : "")
+						+ "' not found in '" + libraryFile.getParentFile().getAbsolutePath()
+						+ "'. Using extracted native library instead.", null );
+				}
 			}
 		}
 
@@ -128,7 +183,7 @@ class FlatNativeLibrary
 			return new NativeLibrary( libraryFile, true );
 
 		// load from FlatLaf jar (extract native library to temp folder)
-		return new NativeLibrary( "com/formdev/flatlaf/natives/" + libraryName, null, true );
+		return new NativeLibrary( "com/formdev/flatlaf/natives/" + libraryName, null, !unknownArch );
 	}
 
 	/**
@@ -145,6 +200,51 @@ class FlatNativeLibrary
 	 *     flatlaf-3.1-linux-x86_64.so
 	 */
 	private static File findLibraryBesideJar( String classifier, String ext ) {
+		// get location of FlatLaf jar (or fat/uber application jar)
+		File jarFile = getJarFile();
+		if( jarFile == null )
+			return null;
+
+		// build library file
+		String libraryName = buildLibraryName( jarFile, classifier, ext );
+		File jarDir = jarFile.getParentFile();
+
+		// check whether native library exists in same directory as jar
+		File libraryFile = new File( jarDir, libraryName );
+		if( libraryFile.isFile() )
+			return libraryFile;
+
+		// if jar is in "lib" directory, then also check whether native library exists
+		// in "../bin" directory
+		if( jarDir.getName().equalsIgnoreCase( "lib" ) ) {
+			libraryFile = new File( jarDir.getParentFile(), "bin/" + libraryName );
+			if( libraryFile.isFile() )
+				return libraryFile;
+		}
+
+		// special case: support Gradle cache when running in development environment
+		//   <user-home>/.gradle/caches/modules-2/files-2.1/com.formdev/flatlaf/<version>/<hash-1>/flatlaf-<version>.jar
+		//   <user-home>/.gradle/caches/modules-2/files-2.1/com.formdev/flatlaf/<version>/<hash-2>/flatlaf-<version>-windows-x86_64.dll
+		String path = jarDir.getAbsolutePath().replace( '\\', '/' );
+		if( path.contains( "/.gradle/caches/" ) ) {
+			File versionDir = jarDir.getParentFile();
+			if( libraryName.contains( versionDir.getName() ) ) {
+				File[] dirs = versionDir.listFiles();
+				if( dirs != null ) {
+					for( File dir : dirs ) {
+						libraryFile = new File( dir, libraryName );
+						if( libraryFile.isFile() )
+							return libraryFile;
+					}
+				}
+			}
+		}
+
+		// native library not found
+		return null;
+	}
+
+	private static File getJarFile() {
 		try {
 			// get location of FlatLaf jar
 			CodeSource codeSource = FlatNativeLibrary.class.getProtectionDomain().getCodeSource();
@@ -162,31 +262,30 @@ class FlatNativeLibrary
 			if( !jarFile.isFile() )
 				return null;
 
-			// build library file
-			String jarName = jarFile.getName();
-			String jarBasename = jarName.substring( 0, jarName.lastIndexOf( '.' ) );
-			File parent = jarFile.getParentFile();
-			String libraryName = jarBasename
-				+ (jarBasename.contains( "flatlaf" ) ? "" : "-flatlaf")
-				+ '-' + classifier + '.' + ext;
-
-			// check whether native library exists in same directory as jar
-			File libraryFile = new File( parent, libraryName );
-			if( libraryFile.isFile() )
-				return libraryFile;
-
-			// if jar is in "lib" directory, then also check whether library exists
-			// in "../bin" directory
-			if( parent.getName().equalsIgnoreCase( "lib" ) ) {
-				libraryFile = new File( parent.getParentFile(), "bin/" + libraryName );
-				if( libraryFile.isFile() )
-					return libraryFile;
-			}
+			return jarFile;
 		} catch( Exception ex ) {
 			LoggingFacade.INSTANCE.logSevere( ex.getMessage(), ex );
+			return null;
+		}
 	}
 
-		return null;
+	private static String buildLibraryName( File jarFile, String classifier, String ext ) {
+		String jarName = jarFile.getName();
+		String jarBasename = jarName.substring( 0, jarName.lastIndexOf( '.' ) );
+
+		// remove classifier "no-natives" (if used)
+		jarBasename = StringUtils.removeTrailing( jarBasename, "-no-natives" );
+
+		return jarBasename
+			+ (jarBasename.contains( "flatlaf" ) ? "" : "-flatlaf")
+			+ '-' + classifier + '.' + ext;
+	}
+
+	/**
+	 * Allow only 'a'-'z', 'A'-'Z', '0'-'9', '_' and '-' in filenames.
+	 */
+	private static String sanitize( String s ) {
+		return s.replaceAll( "[^a-zA-Z0-9_-]", "_" );
 	}
 
 	private static void loadJAWT() {

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatNativeLinuxLibrary.java

@@ -16,6 +16,7 @@
 
 package com.formdev.flatlaf.ui;
 
+import java.awt.GraphicsConfiguration;
 import java.awt.Point;
 import java.awt.Toolkit;
 import java.awt.Window;
@@ -35,13 +36,30 @@ import com.formdev.flatlaf.util.SystemInfo;
  */
 class FlatNativeLinuxLibrary
 {
+	private static int API_VERSION_LINUX = 3001;
+
+	/**
+	 * Checks whether native library is loaded/available.
+	 * <p>
+	 * <b>Note</b>: It is required to invoke this method before invoking any other
+	 *              method of this class. Otherwise, the native library may not be loaded.
+	 */
 	static boolean isLoaded() {
-		return SystemInfo.isLinux && FlatNativeLibrary.isLoaded();
+		return SystemInfo.isLinux && FlatNativeLibrary.isLoaded( API_VERSION_LINUX );
 	}
 
 	// direction for _NET_WM_MOVERESIZE message
-	// see https://specifications.freedesktop.org/wm-spec/wm-spec-latest.html
-	static final int MOVE = 8;
+	// see https://specifications.freedesktop.org/wm-spec/latest/ar01s04.html
+	static final int
+		SIZE_TOPLEFT     = 0,
+		SIZE_TOP         = 1,
+		SIZE_TOPRIGHT    = 2,
+		SIZE_RIGHT       = 3,
+		SIZE_BOTTOMRIGHT = 4,
+		SIZE_BOTTOM      = 5,
+		SIZE_BOTTOMLEFT  = 6,
+		SIZE_LEFT        = 7,
+		MOVE             = 8;
 
 	private static Boolean isXWindowSystem;
 
@@ -88,7 +106,11 @@ class FlatNativeLinuxLibrary
 	}
 
 	private static Point scale( Window window, Point pt ) {
-		AffineTransform transform = window.getGraphicsConfiguration().getDefaultTransform();
+		GraphicsConfiguration gc = window.getGraphicsConfiguration();
+		if( gc == null )
+			return pt;
+
+		AffineTransform transform = gc.getDefaultTransform();
 		int x = (int) Math.round( pt.x * transform.getScaleX() );
 		int y = (int) Math.round( pt.y * transform.getScaleY() );
 		return new Point( x, y );

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatNativeMacLibrary.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2023 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.ui;
+
+import java.awt.Rectangle;
+import java.awt.Window;
+import com.formdev.flatlaf.util.SystemInfo;
+
+/**
+ * Native methods for macOS.
+ * <p>
+ * <b>Note</b>: This is private API. Do not use!
+ *
+ * <h2>Methods that use windows as parameter</h2>
+ *
+ * For all methods that accept a {@link java.awt.Window} as parameter,
+ * the underlying macOS window must be already created,
+ * otherwise the method fails. You can use following to ensure this:
+ * <pre>{@code
+ * if( !window.isDisplayable() )
+ *     window.addNotify();
+ * }</pre>
+ * or invoke the method after packing the window. E.g.
+ * <pre>{@code
+ * window.pack();
+ * }</pre>
+ *
+ * @author Karl Tauber
+ * @since 3.3
+ */
+public class FlatNativeMacLibrary
+{
+	private static int API_VERSION_MACOS = 2001;
+
+	/**
+	 * Checks whether native library is loaded/available.
+	 * <p>
+	 * <b>Note</b>: It is required to invoke this method before invoking any other
+	 *              method of this class. Otherwise, the native library may not be loaded.
+	 */
+	public static boolean isLoaded() {
+		return SystemInfo.isMacOS && FlatNativeLibrary.isLoaded( API_VERSION_MACOS );
+	}
+
+	public native static boolean setWindowRoundedBorder( Window window, float radius, float borderWidth, int borderColor );
+
+	/** @since 3.4 */
+	public static final int
+		BUTTONS_SPACING_DEFAULT = 0,
+		BUTTONS_SPACING_MEDIUM = 1,
+		BUTTONS_SPACING_LARGE = 2;
+
+	/** @since 3.4 */ public native static boolean setWindowButtonsSpacing( Window window, int buttonsSpacing );
+	/** @since 3.4 */ public native static Rectangle getWindowButtonsBounds( Window window );
+	/** @since 3.4 */ public native static boolean isWindowFullScreen( Window window );
+	/** @since 3.4 */ public native static boolean toggleWindowFullScreen( Window window );
+}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatNativeWindowBorder.java

@@ -17,20 +17,27 @@
 package com.formdev.flatlaf.ui;
 
 import java.awt.Color;
+import java.awt.Component;
 import java.awt.Container;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.Point;
 import java.awt.Rectangle;
+import java.awt.Toolkit;
 import java.awt.Window;
 import java.beans.PropertyChangeListener;
-import java.util.List;
+import java.util.function.Predicate;
 import javax.swing.JDialog;
 import javax.swing.JFrame;
 import javax.swing.JRootPane;
+import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
 import javax.swing.event.ChangeListener;
+import javax.swing.plaf.BorderUIResource;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.FlatLaf;
 import com.formdev.flatlaf.FlatSystemProperties;
-import com.formdev.flatlaf.ui.JBRCustomDecorations.JBRWindowTopBorder;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.SystemInfo;
 
 /**
@@ -54,27 +61,15 @@ public class FlatNativeWindowBorder
 		!SystemInfo.isWinPE &&
 		FlatSystemProperties.getBoolean( FlatSystemProperties.USE_WINDOW_DECORATIONS, true );
 
-	// check this field before using class JBRCustomDecorations to avoid unnecessary loading of that class
-	private static final boolean canUseJBRCustomDecorations =
-		canUseWindowDecorations &&
-		SystemInfo.isJetBrainsJVM_11_orLater &&
-		FlatSystemProperties.getBoolean( FlatSystemProperties.USE_JETBRAINS_CUSTOM_DECORATIONS, false );
-
 	private static Boolean supported;
 	private static Provider nativeProvider;
 
 	public static boolean isSupported() {
-		if( canUseJBRCustomDecorations )
-			return JBRCustomDecorations.isSupported();
-
 		initialize();
 		return supported;
 	}
 
 	static Object install( JRootPane rootPane ) {
-		if( canUseJBRCustomDecorations )
-			return JBRCustomDecorations.install( rootPane );
-
 		if( !isSupported() )
 			return null;
 
@@ -163,11 +158,6 @@ public class FlatNativeWindowBorder
 	}
 
 	static void uninstall( JRootPane rootPane, Object data ) {
-		if( canUseJBRCustomDecorations ) {
-			JBRCustomDecorations.uninstall( rootPane, data );
-			return;
-		}
-
 		if( !isSupported() )
 			return;
 
@@ -215,9 +205,6 @@ public class FlatNativeWindowBorder
 	}
 
 	public static boolean hasCustomDecoration( Window window ) {
-		if( canUseJBRCustomDecorations )
-			return JBRCustomDecorations.hasCustomDecoration( window );
-
 		if( !isSupported() )
 			return false;
 
@@ -225,11 +212,6 @@ public class FlatNativeWindowBorder
 	}
 
 	public static void setHasCustomDecoration( Window window, boolean hasCustomDecoration ) {
-		if( canUseJBRCustomDecorations ) {
-			JBRCustomDecorations.setHasCustomDecoration( window, hasCustomDecoration );
-			return;
-		}
-
 		if( !isSupported() )
 			return;
 
@@ -237,23 +219,18 @@ public class FlatNativeWindowBorder
 	}
 
 	static void setTitleBarHeightAndHitTestSpots( Window window, int titleBarHeight,
-		List<Rectangle> hitTestSpots, Rectangle appIconBounds, Rectangle minimizeButtonBounds,
+		Predicate<Point> captionHitTestCallback, Rectangle appIconBounds, Rectangle minimizeButtonBounds,
 		Rectangle maximizeButtonBounds, Rectangle closeButtonBounds )
 	{
-		if( canUseJBRCustomDecorations ) {
-			JBRCustomDecorations.setTitleBarHeightAndHitTestSpots( window, titleBarHeight, hitTestSpots );
-			return;
-		}
-
 		if( !isSupported() )
 			return;
 
-		nativeProvider.updateTitleBarInfo( window, titleBarHeight, hitTestSpots,
+		nativeProvider.updateTitleBarInfo( window, titleBarHeight, captionHitTestCallback,
 			appIconBounds, minimizeButtonBounds, maximizeButtonBounds, closeButtonBounds );
 	}
 
 	static boolean showWindow( Window window, int cmd ) {
-		if( canUseJBRCustomDecorations || !isSupported() )
+		if( !isSupported() )
 			return false;
 
 		return nativeProvider.showWindow( window, cmd );
@@ -294,7 +271,7 @@ public class FlatNativeWindowBorder
 	{
 		boolean hasCustomDecoration( Window window );
 		void setHasCustomDecoration( Window window, boolean hasCustomDecoration );
-		void updateTitleBarInfo( Window window, int titleBarHeight, List<Rectangle> hitTestSpots,
+		void updateTitleBarInfo( Window window, int titleBarHeight, Predicate<Point> captionHitTestCallback,
 			Rectangle appIconBounds, Rectangle minimizeButtonBounds, Rectangle maximizeButtonBounds,
 			Rectangle closeButtonBounds );
 
@@ -320,20 +297,36 @@ public class FlatNativeWindowBorder
 	 * No longer needed since Windows 11.
 	 */
 	static class WindowTopBorder
-		extends JBRCustomDecorations.JBRWindowTopBorder
+		extends BorderUIResource.EmptyBorderUIResource
 	{
 		private static WindowTopBorder instance;
 
-		static JBRWindowTopBorder getInstance() {
-			if( canUseJBRCustomDecorations )
-				return JBRWindowTopBorder.getInstance();
+		private final Color activeLightColor = new Color( 0x707070 );
+		private final Color activeDarkColor = new Color( 0x2D2E2F );
+		private final Color inactiveLightColor = new Color( 0xaaaaaa );
+		private final Color inactiveDarkColor = new Color( 0x494A4B );
 
+		private boolean colorizationAffectsBorders;
+		private Color activeColor;
+
+		static WindowTopBorder getInstance() {
 			if( instance == null )
 				instance = new WindowTopBorder();
 			return instance;
 		}
 
-		@Override
+		WindowTopBorder() {
+			super( 1, 0, 0, 0 );
+
+			update();
+			installListeners();
+        }
+
+        void update() {
+			colorizationAffectsBorders = isColorizationColorAffectsBorders();
+			activeColor = calculateActiveBorderColor();
+		}
+
 		void installListeners() {
 			nativeProvider.addChangeListener( e -> {
 				update();
@@ -346,19 +339,69 @@ public class FlatNativeWindowBorder
 			} );
 		}
 
-		@Override
 		boolean isColorizationColorAffectsBorders() {
 			return nativeProvider.isColorizationColorAffectsBorders();
 		}
 
-		@Override
 		Color getColorizationColor() {
 			return nativeProvider.getColorizationColor();
 		}
 
-		@Override
 		int getColorizationColorBalance() {
 			return nativeProvider.getColorizationColorBalance();
 		}
+
+		private Color calculateActiveBorderColor() {
+			if( !colorizationAffectsBorders )
+				return null;
+
+			Color colorizationColor = getColorizationColor();
+			if( colorizationColor != null ) {
+				int colorizationColorBalance = getColorizationColorBalance();
+				if( colorizationColorBalance < 0 || colorizationColorBalance > 100 )
+					colorizationColorBalance = 100;
+
+				if( colorizationColorBalance == 0 )
+					return new Color( 0xD9D9D9 );
+				if( colorizationColorBalance == 100 )
+					return colorizationColor;
+
+				float alpha = colorizationColorBalance / 100.0f;
+				float remainder = 1 - alpha;
+				int r = Math.round( colorizationColor.getRed() * alpha + 0xD9 * remainder );
+				int g = Math.round( colorizationColor.getGreen() * alpha + 0xD9 * remainder );
+				int b = Math.round( colorizationColor.getBlue() * alpha + 0xD9 * remainder );
+
+				// avoid potential IllegalArgumentException in Color constructor
+				r = Math.min( Math.max( r, 0 ), 255 );
+				g = Math.min( Math.max( g, 0 ), 255 );
+				b = Math.min( Math.max( b, 0 ), 255 );
+
+				return new Color( r, g, b );
+			}
+
+			Color activeBorderColor = (Color) Toolkit.getDefaultToolkit().getDesktopProperty( "win.frame.activeBorderColor" );
+			return (activeBorderColor != null) ? activeBorderColor : UIManager.getColor( "MenuBar.borderColor" );
+		}
+
+		@Override
+		public void paintBorder( Component c, Graphics g, int x, int y, int width, int height ) {
+			Window window = SwingUtilities.windowForComponent( c );
+			boolean active = window != null && window.isActive();
+			boolean dark = FlatLaf.isLafDark();
+
+			g.setColor( active
+				? (activeColor != null ? activeColor : (dark ? activeDarkColor : activeLightColor))
+				: (dark ? inactiveDarkColor : inactiveLightColor) );
+			HiDPIUtils.paintAtScale1x( (Graphics2D) g, x, y, width, height, this::paintImpl );
+		}
+
+		private void paintImpl( Graphics2D g, int x, int y, int width, int height, double scaleFactor ) {
+			g.fillRect( x, y, width, 1 );
+		}
+
+		void repaintBorder( Component c ) {
+			c.repaint( 0, 0, c.getWidth(), 1 );
+		}
 	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatNativeWindowsLibrary.java

@@ -16,6 +16,7 @@
 
 package com.formdev.flatlaf.ui;
 
+import java.awt.Color;
 import java.awt.Window;
 import com.formdev.flatlaf.util.SystemInfo;
 
@@ -29,10 +30,18 @@ import com.formdev.flatlaf.util.SystemInfo;
  */
 public class FlatNativeWindowsLibrary
 {
+	private static int API_VERSION_WINDOWS = 1001;
+
 	private static long osBuildNumber = Long.MIN_VALUE;
 
+	/**
+	 * Checks whether native library is loaded/available.
+	 * <p>
+	 * <b>Note</b>: It is required to invoke this method before invoking any other
+	 *              method of this class. Otherwise, the native library may not be loaded.
+	 */
 	public static boolean isLoaded() {
-		return SystemInfo.isWindows && FlatNativeLibrary.isLoaded();
+		return SystemInfo.isWindows && FlatNativeLibrary.isLoaded( API_VERSION_WINDOWS );
 	}
 
 	/**
@@ -93,15 +102,60 @@ public class FlatNativeWindowsLibrary
 	public native static boolean setWindowCornerPreference( long hwnd, int cornerPreference );
 
 	/**
-	 * Sets the color of the window border.
-	 * The red/green/blue values must be in range {@code 0 - 255}.
-	 * If red is {@code -1}, then the system default border color is used (useful to reset the border color).
-	 * If red is {@code -2}, then no border is painted.
-	 * <p>
-	 * Invokes Win32 API method {@code DwmSetWindowAttribute(DWMWA_BORDER_COLOR)}.
+	 * DWMWINDOWATTRIBUTE
+	 * see https://learn.microsoft.com/en-us/windows/win32/api/dwmapi/ne-dwmapi-dwmwindowattribute
+	 *
+	 * @since 3.3
+	 */
+	public static final int
+		DWMWA_USE_IMMERSIVE_DARK_MODE = 20,
+		DWMWA_BORDER_COLOR = 34,
+		DWMWA_CAPTION_COLOR = 35,
+		DWMWA_TEXT_COLOR = 36;
+
+	/**
+	 * Invokes Win32 API method {@code DwmSetWindowAttribute()} with a {@code BOOL} attribute value.
+	 * See https://learn.microsoft.com/en-us/windows/win32/api/dwmapi/nf-dwmapi-dwmsetwindowattribute
+	 *
+	 * @since 3.3
+	 */
+	public native static boolean dwmSetWindowAttributeBOOL( long hwnd, int attribute, boolean value );
+
+	/**
+	 * Invokes Win32 API method {@code DwmSetWindowAttribute()} with a {@code DWORD} attribute value.
+	 * See https://learn.microsoft.com/en-us/windows/win32/api/dwmapi/nf-dwmapi-dwmsetwindowattribute
+	 *
+	 * @since 3.3
+	 */
+	public native static boolean dwmSetWindowAttributeDWORD( long hwnd, int attribute, int value );
+
+	/** @since 3.3 */
+	public static final int
+		// use this constant to reset any window part colors to the system default behavior
+		DWMWA_COLOR_DEFAULT = 0xFFFFFFFF,
+		// use this constant to specify that a window part should not be rendered
+		DWMWA_COLOR_NONE = 0xFFFFFFFE;
+
+	/** @since 3.3 */
+	public static final Color COLOR_NONE = new Color( 0, true );
+
+	/**
+	 * Invokes Win32 API method {@code DwmSetWindowAttribute()} with a {@code COLORREF} attribute value.
 	 * See https://learn.microsoft.com/en-us/windows/win32/api/dwmapi/nf-dwmapi-dwmsetwindowattribute
 	 * <p>
 	 * Supported since Windows 11 Build 22000.
+	 *
+	 * @since 3.3
 	 */
-	public native static boolean setWindowBorderColor( long hwnd, int red, int green, int blue );
+	public static boolean dwmSetWindowAttributeCOLORREF( long hwnd, int attribute, Color color ) {
+		// convert color to Windows RGB value
+		int rgb = (color == COLOR_NONE)
+			? DWMWA_COLOR_NONE
+			: (color != null
+				? (color.getRed() | (color.getGreen() << 8) | (color.getBlue() << 16))
+				: DWMWA_COLOR_DEFAULT);
+
+		// DwmSetWindowAttribute() expects COLORREF as attribute value, which is defined as DWORD
+		return dwmSetWindowAttributeDWORD( hwnd, attribute, rgb );
+	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatOptionPaneUI.java

@@ -30,9 +30,7 @@ import javax.swing.JPanel;
 import javax.swing.JRootPane;
 import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
-import javax.swing.border.Border;
 import javax.swing.plaf.ComponentUI;
-import javax.swing.plaf.UIResource;
 import javax.swing.plaf.basic.BasicHTML;
 import javax.swing.plaf.basic.BasicOptionPaneUI;
 import com.formdev.flatlaf.FlatClientProperties;
@@ -115,13 +113,6 @@ public class FlatOptionPaneUI
 		sameSizeButtons = FlatUIUtils.getUIBoolean( "OptionPane.sameSizeButtons", true );
 	}
 
-	@Override
-	protected void installComponents() {
-		super.installComponents();
-
-		updateChildPanels( optionPane );
-	}
-
 	@Override
 	protected PropertyChangeListener createPropertyChangeListener() {
 		PropertyChangeListener superListener = super.createPropertyChangeListener();
@@ -155,6 +146,13 @@ public class FlatOptionPaneUI
 	protected Container createMessageArea() {
 		Container messageArea = super.createMessageArea();
 
+		// use non-UIResource OptionPane.messageAreaBorder to avoid that it is replaced when switching LaF
+		// and make panel non-opaque for OptionPane.background
+		updateAreaPanel( messageArea );
+
+		// make known sub-panels non-opaque for OptionPane.background
+		updateKnownChildPanels( messageArea );
+
 		// set icon-message gap
 		if( iconMessageGap > 0 ) {
 			Component iconMessageSeparator = SwingUtils.getComponentByName( messageArea, "OptionPane.separator" );
@@ -169,6 +167,10 @@ public class FlatOptionPaneUI
 	protected Container createButtonArea() {
 		Container buttonArea = super.createButtonArea();
 
+		// use non-UIResource OptionPane.buttonAreaBorder to avoid that it is replaced when switching LaF
+		// and make panel non-opaque for OptionPane.background
+		updateAreaPanel( buttonArea );
+
 		// scale button padding and subtract focusWidth
 		if( buttonArea.getLayout() instanceof ButtonAreaLayout ) {
 			ButtonAreaLayout layout = (ButtonAreaLayout) buttonArea.getLayout();
@@ -218,22 +220,33 @@ public class FlatOptionPaneUI
 		super.addMessageComponents( container, cons, msg, maxll, internallyCreated );
 	}
 
-	private void updateChildPanels( Container c ) {
-		for( Component child : c.getComponents() ) {
-			if( child.getClass() == JPanel.class ) {
-				JPanel panel = (JPanel)child;
+	private void updateAreaPanel( Container area ) {
+		if( !(area instanceof JPanel) )
+			return;
 
-				// make sub-panel non-opaque for OptionPane.background
+		// use non-UIResource border to avoid that it is replaced when switching LaF
+		// and make panel non-opaque for OptionPane.background
+		JPanel panel = (JPanel) area;
+		panel.setBorder( FlatUIUtils.nonUIResource( panel.getBorder() ) );
 		panel.setOpaque( false );
+	}
 
-				// use non-UIResource borders to avoid that they are replaced when switching LaF
-				Border border = panel.getBorder();
-				if( border instanceof UIResource )
-					panel.setBorder( FlatUIUtils.nonUIResource( border ) );
+	private void updateKnownChildPanels( Container c ) {
+		for( Component child : c.getComponents() ) {
+			if( child instanceof JPanel && child.getName() != null ) {
+				switch( child.getName() ) {
+					case "OptionPane.realBody":
+					case "OptionPane.body":
+					case "OptionPane.separator":
+					case "OptionPane.break":
+						// make known sub-panels non-opaque for OptionPane.background
+						((JPanel)child).setOpaque( false );
+						break;
+				}
 			}
 
 			if( child instanceof Container )
-				updateChildPanels( (Container) child );
+				updateKnownChildPanels( (Container) child );
 		}
 	}
 

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatPanelUI.java

@@ -16,6 +16,7 @@
 
 package com.formdev.flatlaf.ui;
 
+import java.awt.Dimension;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.beans.PropertyChangeEvent;
@@ -23,11 +24,14 @@ import java.beans.PropertyChangeListener;
 import java.util.Map;
 import javax.swing.JComponent;
 import javax.swing.JPanel;
+import javax.swing.LookAndFeel;
+import javax.swing.border.Border;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.basic.BasicPanelUI;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.UIScale;
 
@@ -69,6 +73,8 @@ public class FlatPanelUI
 		super.installUI( c );
 
 		c.addPropertyChangeListener( this );
+		if( c.getClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER ) != null )
+			FullWindowContentSupport.registerPlaceholder( c );
 
 		installStyle( (JPanel) c );
 	}
@@ -78,10 +84,20 @@ public class FlatPanelUI
 		super.uninstallUI( c );
 
 		c.removePropertyChangeListener( this );
+		if( c.getClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER ) != null )
+			FullWindowContentSupport.unregisterPlaceholder( c );
 
 		oldStyleValues = null;
 	}
 
+	@Override
+	protected void installDefaults( JPanel p ) {
+		super.installDefaults( p );
+
+		if( p.getClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER ) != null )
+			LookAndFeel.installProperty( p, "opaque", false );
+	}
+
 	/** @since 2.0.1 */
 	@Override
 	public void propertyChange( PropertyChangeEvent e ) {
@@ -96,7 +112,18 @@ public class FlatPanelUI
 				} else
 					installStyle( c );
 				c.revalidate();
-				c.repaint();
+				HiDPIUtils.repaint( c );
+				break;
+
+			case FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER:
+				JPanel p = (JPanel) e.getSource();
+				if( e.getOldValue() != null )
+					FullWindowContentSupport.unregisterPlaceholder( p );
+				if( e.getNewValue() != null )
+					FullWindowContentSupport.registerPlaceholder( p );
+
+				// make panel non-opaque for placeholders
+				LookAndFeel.installProperty( p, "opaque", e.getNewValue() == null );
 				break;
 		}
 	}
@@ -135,31 +162,52 @@ public class FlatPanelUI
 
 	@Override
 	public void update( Graphics g, JComponent c ) {
-		// fill background
-		if( c.isOpaque() ) {
-			int width = c.getWidth();
-			int height = c.getHeight();
-			int arc = (this.arc >= 0)
-				? this.arc
-				: ((c.getBorder() instanceof FlatLineBorder)
-					? ((FlatLineBorder)c.getBorder()).getArc()
-					: 0);
-
-			// fill background with parent color to avoid garbage in rounded corners
-			if( arc > 0 )
-				FlatUIUtils.paintParentBackground( g, c );
-
-			g.setColor( c.getBackground() );
-			if( arc > 0 ) {
-				// fill rounded rectangle if having rounded corners
-				Object[] oldRenderingHints = FlatUIUtils.setRenderingHints( g );
-				FlatUIUtils.paintComponentBackground( (Graphics2D) g, 0, 0, width, height,
-					0, UIScale.scale( arc ) );
-				FlatUIUtils.resetRenderingHints( g, oldRenderingHints );
-			} else
-				g.fillRect( 0, 0, width, height );
-		}
-
+		fillRoundedBackground( g, c, arc );
 		paint( g, c );
 	}
+
+	/** @since 3.5 */
+	public static void fillRoundedBackground( Graphics g, JComponent c, int arc ) {
+		if( arc < 0 ) {
+			Border border = c.getBorder();
+			arc = ((border instanceof FlatLineBorder)
+				? ((FlatLineBorder)border).getArc()
+				: 0);
+		}
+
+		// fill background
+		if( c.isOpaque() ) {
+			if( arc > 0 ) {
+				// fill background with parent color to avoid garbage in rounded corners
+				FlatUIUtils.paintParentBackground( g, c );
+			} else {
+				g.setColor( c.getBackground() );
+				g.fillRect( 0, 0, c.getWidth(), c.getHeight() );
+			}
+		}
+
+		// fill rounded rectangle if having rounded corners
+		if( arc > 0 ) {
+			g.setColor( c.getBackground() );
+			Object[] oldRenderingHints = FlatUIUtils.setRenderingHints( g );
+			FlatUIUtils.paintComponentBackground( (Graphics2D) g, 0, 0, c.getWidth(), c.getHeight(),
+				0, UIScale.scale( arc ) );
+			FlatUIUtils.resetRenderingHints( g, oldRenderingHints );
+		}
+	}
+
+	@Override
+	public Dimension getPreferredSize( JComponent c ) {
+		Object value = c.getClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER );
+		if( value != null )
+			return FullWindowContentSupport.getPlaceholderPreferredSize( c, (String) value );
+
+		return super.getPreferredSize( c );
+	}
+
+	@Override
+	public void paint( Graphics g, JComponent c ) {
+		if( c.getClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER ) != null )
+			FullWindowContentSupport.debugPaint( g, c );
+	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatPasswordFieldUI.java

@@ -43,6 +43,7 @@ import javax.swing.text.View;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.icons.FlatCapsLockIcon;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.UIScale;
 
 /**
@@ -163,7 +164,7 @@ public class FlatPasswordFieldUI
 			}
 			private void repaint( KeyEvent e ) {
 				if( e.getKeyCode() == KeyEvent.VK_CAPS_LOCK ) {
-					e.getComponent().repaint();
+					HiDPIUtils.repaint( e.getComponent() );
 					scrollCaretToVisible();
 				}
 			}
@@ -326,7 +327,7 @@ public class FlatPasswordFieldUI
 		if( visible != revealButton.isVisible() ) {
 			revealButton.setVisible( visible );
 			c.revalidate();
-			c.repaint();
+			HiDPIUtils.repaint( c );
 
 			if( !visible ) {
 				revealButton.setSelected( false );

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatPopupFactory.java

@@ -17,6 +17,7 @@
 package com.formdev.flatlaf.ui;
 
 import java.awt.AWTEvent;
+import java.awt.BorderLayout;
 import java.awt.Color;
 import java.awt.Component;
 import java.awt.Container;
@@ -31,16 +32,19 @@ import java.awt.Panel;
 import java.awt.Point;
 import java.awt.PointerInfo;
 import java.awt.Rectangle;
-import java.awt.Toolkit;
 import java.awt.Window;
 import java.awt.event.ComponentEvent;
 import java.awt.event.ComponentListener;
+import java.awt.event.HierarchyEvent;
+import java.awt.event.HierarchyListener;
 import java.awt.event.MouseEvent;
 import java.awt.event.WindowFocusListener;
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.MethodType;
 import java.lang.reflect.Method;
+import java.util.ArrayList;
+import java.util.concurrent.atomic.AtomicReference;
 import javax.swing.JComponent;
 import javax.swing.JLayeredPane;
 import javax.swing.JPanel;
@@ -58,6 +62,7 @@ import javax.swing.border.EmptyBorder;
 import javax.swing.border.LineBorder;
 import javax.swing.plaf.basic.BasicComboPopup;
 import com.formdev.flatlaf.FlatClientProperties;
+import com.formdev.flatlaf.FlatSystemProperties;
 import com.formdev.flatlaf.util.SystemInfo;
 import com.formdev.flatlaf.util.UIScale;
 
@@ -71,9 +76,13 @@ import com.formdev.flatlaf.util.UIScale;
 public class FlatPopupFactory
 	extends PopupFactory
 {
+	static final String KEY_POPUP_USES_NATIVE_BORDER = "FlatLaf.internal.FlatPopupFactory.popupUsesNativeBorder";
+
 	private MethodHandle java8getPopupMethod;
 	private MethodHandle java9getPopupMethod;
 
+	private final ArrayList<NonFlashingPopup> stillShownHeavyWeightPopups = new ArrayList<>();
+
 	@Override
 	public Popup getPopup( Component owner, Component contents, int x, int y )
 		throws IllegalArgumentException
@@ -86,23 +95,39 @@ public class FlatPopupFactory
 
 		fixLinuxWaylandJava21focusIssue( owner );
 
+		// reuse a heavy weight popup window, which is still shown on screen,
+		// to avoid flicker when popup (e.g. tooltip) is moving while mouse is moved
+		for( NonFlashingPopup popup : stillShownHeavyWeightPopups ) {
+			if( popup.delegate != null &&
+				popup.owner == owner &&
+				(popup.contents == contents ||
+				 (popup.contents instanceof JToolTip && contents instanceof JToolTip)) )
+			{
+				stillShownHeavyWeightPopups.remove( popup );
+				return reuseStillShownHeavyWeightPopups( popup, contents, x, y );
+			}
+		}
+
 		boolean forceHeavyWeight = isOptionEnabled( owner, contents, FlatClientProperties.POPUP_FORCE_HEAVY_WEIGHT, "Popup.forceHeavyWeight" );
 
 		if( !isOptionEnabled( owner, contents, FlatClientProperties.POPUP_DROP_SHADOW_PAINTED, "Popup.dropShadowPainted" ) || SystemInfo.isProjector || SystemInfo.isWebswing )
-			return new NonFlashingPopup( getPopupForScreenOfOwner( owner, contents, x, y, forceHeavyWeight ), contents );
+			return new NonFlashingPopup( getPopupForScreenOfOwner( owner, contents, x, y, forceHeavyWeight ), owner, contents );
 
 		// macOS and Linux adds drop shadow to heavy weight popups
-		if( SystemInfo.isMacOS || SystemInfo.isLinux )
-			return new NonFlashingPopup( getPopupForScreenOfOwner( owner, contents, x, y, true ), contents );
+		if( SystemInfo.isMacOS || SystemInfo.isLinux ) {
+			NonFlashingPopup popup = new NonFlashingPopup( getPopupForScreenOfOwner( owner, contents, x, y, true ), owner, contents );
+			if( popup.popupWindow != null && isMacOSBorderSupported() )
+				setupRoundedBorder( popup.popupWindow, owner, contents );
+			return popup;
+		}
 
 		// Windows 11 with FlatLaf native library can use rounded corners and shows drop shadow for heavy weight popups
-		int borderCornerRadius;
 		if( isWindows11BorderSupported() &&
-			(borderCornerRadius = getBorderCornerRadius( owner, contents )) > 0 )
+			getBorderCornerRadius( owner, contents ) > 0 )
 		{
-			NonFlashingPopup popup = new NonFlashingPopup( getPopupForScreenOfOwner( owner, contents, x, y, true ), contents );
+			NonFlashingPopup popup = new NonFlashingPopup( getPopupForScreenOfOwner( owner, contents, x, y, true ), owner, contents );
 			if( popup.popupWindow != null )
-				setupWindows11Border( popup.popupWindow, contents, borderCornerRadius );
+				setupRoundedBorder( popup.popupWindow, owner, contents );
 			return popup;
 		}
 
@@ -111,7 +136,11 @@ public class FlatPopupFactory
 			forceHeavyWeight = true;
 
 		// create drop shadow popup
-		return new DropShadowPopup( getPopupForScreenOfOwner( owner, contents, x, y, forceHeavyWeight ), owner, contents );
+		Popup popupForScreenOfOwner = getPopupForScreenOfOwner( owner, contents, x, y, forceHeavyWeight );
+		GraphicsConfiguration gc = (owner != null) ? owner.getGraphicsConfiguration() : null;
+		return (gc != null && gc.isTranslucencyCapable())
+			? new DropShadowPopup( popupForScreenOfOwner, owner, contents )
+			: new NonFlashingPopup( popupForScreenOfOwner, owner, contents );
 	}
 
 	/**
@@ -162,67 +191,6 @@ public class FlatPopupFactory
 		}
 	}
 
-	/**
-	 * Shows the given popup and, if necessary, fixes the location of a heavy weight popup window.
-	 * <p>
-	 * On a dual screen setup, where screens use different scale factors, it may happen
-	 * that the window location changes when showing a heavy weight popup window.
-	 * E.g. when opening a dialog on the secondary screen and making combobox popup visible.
-	 * <p>
-	 * This is a workaround for https://bugs.openjdk.java.net/browse/JDK-8224608
-	 */
-	private static void showPopupAndFixLocation( Popup popup, Window popupWindow ) {
-		if( popupWindow != null ) {
-			// remember location of heavy weight popup window
-			int x = popupWindow.getX();
-			int y = popupWindow.getY();
-
-			popup.show();
-
-			// restore popup window location if it has changed
-			// (probably scaled when screens use different scale factors)
-			if( popupWindow.getX() != x || popupWindow.getY() != y )
-				popupWindow.setLocation( x, y );
-		} else
-			popup.show();
-	}
-
-	private boolean isOptionEnabled( Component owner, Component contents, String clientKey, String uiKey ) {
-		Object value = getOption( owner, contents, clientKey, uiKey );
-		return (value instanceof Boolean) ? (Boolean) value : false;
-	}
-
-	private int getBorderCornerRadius( Component owner, Component contents ) {
-		String uiKey =
-			(contents instanceof BasicComboPopup) ? "ComboBox.borderCornerRadius" :
-			(contents instanceof JPopupMenu) ? "PopupMenu.borderCornerRadius" :
-			(contents instanceof JToolTip) ? "ToolTip.borderCornerRadius" :
-			"Popup.borderCornerRadius";
-
-		Object value = getOption( owner, contents, FlatClientProperties.POPUP_BORDER_CORNER_RADIUS, uiKey );
-		return (value instanceof Integer) ? (Integer) value : 0;
-	}
-
-	/**
-	 * Get option from:
-	 * <ol>
-	 * <li>client property {@code clientKey} of {@code owner}
-	 * <li>client property {@code clientKey} of {@code contents}
-	 * <li>UI property {@code uiKey}
-	 * </ol>
-	 */
-	private Object getOption( Component owner, Component contents, String clientKey, String uiKey ) {
-		for( Component c : new Component[] { owner, contents } ) {
-			if( c instanceof JComponent ) {
-				Object value = ((JComponent)c).getClientProperty( clientKey );
-				if( value != null )
-					return value;
-			}
-		}
-
-		return UIManager.get( uiKey );
-	}
-
 	/**
 	 * There is no API in Java 8 to force creation of heavy weight popups,
 	 * but it is possible with reflection. Java 9 provides a new method.
@@ -258,6 +226,51 @@ public class FlatPopupFactory
 		}
 	}
 
+	private static boolean isOptionEnabled( Component owner, Component contents, String clientKey, String uiKey ) {
+		Object value = getOption( owner, contents, clientKey, uiKey );
+		return (value instanceof Boolean) ? (Boolean) value : false;
+	}
+
+	/**
+	 * Get option from:
+	 * <ol>
+	 * <li>client property {@code clientKey} of {@code owner}
+	 * <li>client property {@code clientKey} of {@code contents}
+	 * <li>UI property {@code uiKey}
+	 * </ol>
+	 */
+	private static Object getOption( Component owner, Component contents, String clientKey, String uiKey ) {
+		for( Component c : new Component[] { owner, contents } ) {
+			if( c instanceof JComponent ) {
+				Object value = ((JComponent)c).getClientProperty( clientKey );
+				if( value != null )
+					return value;
+			}
+		}
+
+		return UIManager.get( uiKey );
+	}
+
+	/**
+	 * Reuse a heavy weight popup window, which is still shown on screen,
+	 * by updating window location and contents.
+	 * This avoid flicker when popup (e.g. a tooltip) is moving while mouse is moved.
+	 * E.g. overridden JComponent.getToolTipLocation(MouseEvent).
+	 * See ToolTipManager.checkForTipChange(MouseEvent).
+	 */
+	private static NonFlashingPopup reuseStillShownHeavyWeightPopups(
+		NonFlashingPopup reusePopup, Component contents, int ownerX, int ownerY )
+	{
+		// clone popup because PopupFactory.getPopup() should not return old instance
+		NonFlashingPopup popup = reusePopup.cloneForReuse();
+
+		// update popup location, size and contents
+		popup.reset( contents, ownerX, ownerY );
+		return popup;
+	}
+
+	//---- tooltips -----------------------------------------------------------
+
 	/**
 	 * Usually ToolTipManager places a tooltip at (mouseLocation.x, mouseLocation.y + 20).
 	 * In case that the tooltip would be partly outside of the screen,
@@ -292,13 +305,13 @@ public class FlatPopupFactory
 				break;
 			}
 		}
-		if( gc == null )
+		if( gc == null && owner != null )
 			gc = owner.getGraphicsConfiguration();
 		if( gc == null )
 			return null;
 
 		Rectangle screenBounds = gc.getBounds();
-		Insets screenInsets = Toolkit.getDefaultToolkit().getScreenInsets( gc );
+		Insets screenInsets = FlatUIUtils.getScreenInsets( gc );
 		int screenTop = screenBounds.y + screenInsets.top;
 
 		// place tooltip above mouse location if there is enough space
@@ -342,16 +355,66 @@ public class FlatPopupFactory
 			((JComponent)owner).getToolTipLocation( me ) != null;
 	}
 
+	//---- native rounded border ----------------------------------------------
+
 	private static boolean isWindows11BorderSupported() {
-		return SystemInfo.isWindows_11_orLater && FlatNativeWindowsLibrary.isLoaded();
+		return SystemInfo.isWindows_11_orLater &&
+			FlatSystemProperties.getBoolean( FlatSystemProperties.USE_ROUNDED_POPUP_BORDER, true ) &&
+			FlatNativeWindowsLibrary.isLoaded();
 	}
 
-	private static void setupWindows11Border( Window popupWindow, Component contents, int borderCornerRadius ) {
-		// make sure that the Windows 11 window is created
-		if( !popupWindow.isDisplayable() )
-			popupWindow.addNotify();
+	private static boolean isMacOSBorderSupported() {
+		return SystemInfo.isMacOS &&
+			FlatSystemProperties.getBoolean( FlatSystemProperties.USE_ROUNDED_POPUP_BORDER, true ) &&
+			FlatNativeMacLibrary.isLoaded();
+	}
 
-		// get window handle
+	private static void setupRoundedBorder( Window popupWindow, Component owner, Component contents ) {
+		int borderCornerRadius = getBorderCornerRadius( owner, contents );
+		float borderWidth = getRoundedBorderWidth( owner, contents );
+
+		// get Swing border color
+		Color borderColor;
+		if( contents instanceof JComponent ) {
+			Border border = ((JComponent)contents).getBorder();
+			border = FlatUIUtils.unwrapNonUIResourceBorder( border );
+
+			// get color from border of contents (e.g. JPopupMenu or JToolTip)
+			if( border instanceof FlatLineBorder )
+				borderColor = ((FlatLineBorder)border).getLineColor();
+			else if( border instanceof LineBorder )
+				borderColor = ((LineBorder)border).getLineColor();
+			else if( border instanceof EmptyBorder )
+				borderColor = FlatNativeWindowsLibrary.COLOR_NONE; // do not paint border
+			else
+				borderColor = null; // use system default color
+
+			// avoid that FlatLineBorder paints the Swing border
+			((JComponent)contents).putClientProperty( KEY_POPUP_USES_NATIVE_BORDER, true );
+		} else
+			borderColor = null; // use system default color
+
+		if( popupWindow.isDisplayable() ) {
+			// native window already created
+			setupRoundedBorderImpl( popupWindow, borderCornerRadius, borderWidth, borderColor );
+		} else {
+			// native window not yet created --> add listener to set native border after window creation
+			AtomicReference<HierarchyListener> l = new AtomicReference<>();
+			l.set( e -> {
+				if( e.getID() == HierarchyEvent.HIERARCHY_CHANGED &&
+					(e.getChangeFlags() & HierarchyEvent.DISPLAYABILITY_CHANGED) != 0 )
+				{
+					setupRoundedBorderImpl( popupWindow, borderCornerRadius, borderWidth, borderColor );
+					popupWindow.removeHierarchyListener( l.get() );
+				}
+			} );
+			popupWindow.addHierarchyListener( l.get() );
+		}
+	}
+
+	private static void setupRoundedBorderImpl( Window popupWindow, int borderCornerRadius, float borderWidth, Color borderColor ) {
+		if( SystemInfo.isWindows ) {
+			// get native window handle
 			long hwnd = FlatNativeWindowsLibrary.getHWND( popupWindow );
 
 			// set corner preference
@@ -361,30 +424,16 @@ public class FlatPopupFactory
 			FlatNativeWindowsLibrary.setWindowCornerPreference( hwnd, cornerPreference );
 
 			// set border color
-		int red = -1; // use system default color
-		int green = 0;
-		int blue = 0;
-		if( contents instanceof JComponent ) {
-			Border border = ((JComponent)contents).getBorder();
-			border = FlatUIUtils.unwrapNonUIResourceBorder( border );
+			FlatNativeWindowsLibrary.dwmSetWindowAttributeCOLORREF( hwnd, FlatNativeWindowsLibrary.DWMWA_BORDER_COLOR, borderColor );
+		} else if( SystemInfo.isMacOS ) {
+			if( borderColor == null || borderColor == FlatNativeWindowsLibrary.COLOR_NONE )
+				borderWidth = 0;
 
-			// get color from border of contents (e.g. JPopupMenu or JToolTip)
-			Color borderColor = null;
-			if( border instanceof FlatLineBorder )
-				borderColor = ((FlatLineBorder)border).getLineColor();
-			else if( border instanceof LineBorder )
-				borderColor = ((LineBorder)border).getLineColor();
-			else if( border instanceof EmptyBorder )
-				red = -2; // do not paint border
-
-			if( borderColor != null ) {
-				red = borderColor.getRed();
-				green = borderColor.getGreen();
-				blue = borderColor.getBlue();
+			// set corner radius, border width and color
+			FlatNativeMacLibrary.setWindowRoundedBorder( popupWindow, borderCornerRadius,
+				borderWidth, (borderColor != null) ? borderColor.getRGB() : 0 );
 		}
 	}
-		FlatNativeWindowsLibrary.setWindowBorderColor( hwnd, red, green, blue );
-	}
 
 	private static void resetWindows11Border( Window popupWindow ) {
 		// get window handle
@@ -396,6 +445,30 @@ public class FlatPopupFactory
 		FlatNativeWindowsLibrary.setWindowCornerPreference( hwnd, FlatNativeWindowsLibrary.DWMWCP_DONOTROUND );
 	}
 
+	private static int getBorderCornerRadius( Component owner, Component contents ) {
+		String uiKey =
+			(contents instanceof BasicComboPopup) ? "ComboBox.borderCornerRadius" :
+			(contents instanceof JPopupMenu) ? "PopupMenu.borderCornerRadius" :
+			(contents instanceof JToolTip) ? "ToolTip.borderCornerRadius" :
+			"Popup.borderCornerRadius";
+
+		Object value = getOption( owner, contents, FlatClientProperties.POPUP_BORDER_CORNER_RADIUS, uiKey );
+		return (value instanceof Integer) ? (Integer) value : 0;
+	}
+
+	private static float getRoundedBorderWidth( Component owner, Component contents ) {
+		String uiKey =
+			(contents instanceof BasicComboPopup) ? "ComboBox.roundedBorderWidth" :
+			(contents instanceof JPopupMenu) ? "PopupMenu.roundedBorderWidth" :
+			(contents instanceof JToolTip) ? "ToolTip.roundedBorderWidth" :
+			"Popup.roundedBorderWidth";
+
+		Object value = getOption( owner, contents, FlatClientProperties.POPUP_ROUNDED_BORDER_WIDTH, uiKey );
+		return (value instanceof Number) ? ((Number)value).floatValue() : 0;
+	}
+
+	//---- fixes --------------------------------------------------------------
+
 	private static boolean overlapsHeavyWeightComponent( Component owner, Component contents, int x, int y ) {
 		if( owner == null )
 			return false;
@@ -430,7 +503,7 @@ public class FlatPopupFactory
 	 * On Linux with Wayland, since Java 21, Swing adds a window focus listener to popup owner/invoker window,
 	 * which hides the popup as soon as the owner/invoker window looses focus.
 	 * This works fine for light-weight popups.
-	 * It also works for heavy-weight popups if the do not request focus.
+	 * It also works for heavy-weight popups if they do not request focus.
 	 * Because FlatLaf always uses heavy-weight popups, all popups that request focus
 	 * are broken since Java 21.
 	 *
@@ -458,20 +531,66 @@ public class FlatPopupFactory
 		}
 	}
 
+	/**
+	 * Shows the given popup and, if necessary, fixes the location of a heavy weight popup window.
+	 * <p>
+	 * On a dual screen setup, where screens use different scale factors, it may happen
+	 * that the window location changes when showing a heavy weight popup window.
+	 * E.g. when opening a dialog on the secondary screen and making combobox popup visible.
+	 * <p>
+	 * This is a workaround for https://bugs.openjdk.java.net/browse/JDK-8224608
+	 */
+	private static void showPopupAndFixLocation( Popup popup, Window popupWindow ) {
+		if( popupWindow != null ) {
+			// remember location of heavy weight popup window
+			int x = popupWindow.getX();
+			int y = popupWindow.getY();
+
+			if( !popupWindow.isVisible() )
+				popup.show();
+			else {
+				// if the popup window is already visible (because it is reused),
+				// do not invoke Popup.show() because this would invoke Window.toFront(),
+				// which may have the side effect that an inactive owner window
+				// would be also moved to front and maybe hide previously active window
+				popupWindow.pack();
+			}
+
+			// restore popup window location if it has changed
+			// (probably scaled when screens use different scale factors)
+			if( popupWindow.getX() != x || popupWindow.getY() != y )
+				popupWindow.setLocation( x, y );
+		} else
+			popup.show();
+	}
+
 	//---- class NonFlashingPopup ---------------------------------------------
 
-	private static class NonFlashingPopup
+	/**
+	 * Fixes popup background flashing effect when using dark theme on light platform theme,
+	 * where the light popup background is shown for a fraction of a second before
+	 * the dark popup content is shown.
+	 * This is fixed by setting popup background to content background.
+	 * <p>
+	 * Defers hiding of heavy weight popup window for an event cycle,
+	 * which allows reusing popup window to avoid flicker when "moving" popup.
+	 */
+	private class NonFlashingPopup
 		extends Popup
 	{
 		private Popup delegate;
+		Component owner;
 		private Component contents;
 
 		// heavy weight
-		protected Window popupWindow;
+		Window popupWindow;
 		private Color oldPopupWindowBackground;
 
-		NonFlashingPopup( Popup delegate, Component contents ) {
+		private boolean disposed;
+
+		NonFlashingPopup( Popup delegate, Component owner, Component contents ) {
 			this.delegate = delegate;
+			this.owner = owner;
 			this.contents = contents;
 
 			popupWindow = SwingUtilities.windowForComponent( contents );
@@ -485,9 +604,51 @@ public class FlatPopupFactory
 			}
 		}
 
+		private NonFlashingPopup( NonFlashingPopup reusePopup ) {
+			delegate = reusePopup.delegate;
+			owner = reusePopup.owner;
+			contents = reusePopup.contents;
+			popupWindow = reusePopup.popupWindow;
+			oldPopupWindowBackground = reusePopup.oldPopupWindowBackground;
+		}
+
+		NonFlashingPopup cloneForReuse() {
+			return new NonFlashingPopup( this );
+		}
+
 		@Override
-		public void show() {
+		public final void show() {
+			if( disposed )
+				return;
+
+			showImpl();
+		}
+
+		void showImpl() {
 			if( delegate != null ) {
+				// On macOS and Linux, the empty popup window is shown in popup.show()
+				// (in peer.setVisible(true) invoked from Component.show()),
+				// but the popup content is painted later via repaint manager.
+				// This may cause some flicker, especially during JVM warm-up or
+				// when running JVM in interpreter mode (option -Xint).
+				// To reduce flicker, immediately paint popup content as soon as popup window becomes visible.
+				// This also fixes a problem with JetBrainsRuntime JVM, where sometimes the popups were empty.
+				if( (SystemInfo.isMacOS || SystemInfo.isLinux) && popupWindow instanceof JWindow ) {
+					HierarchyListener l = e -> {
+						if( e.getID() == HierarchyEvent.HIERARCHY_CHANGED &&
+							(e.getChangeFlags() & HierarchyEvent.SHOWING_CHANGED) != 0 )
+						{
+							((JWindow)popupWindow).getRootPane().paintImmediately(
+								0, 0, popupWindow.getWidth(), popupWindow.getHeight() );
+						}
+					};
+					popupWindow.addHierarchyListener( l );
+					try {
+						showPopupAndFixLocation( delegate, popupWindow );
+					} finally {
+						popupWindow.removeHierarchyListener( l );
+					}
+				} else
 					showPopupAndFixLocation( delegate, popupWindow );
 
 				// increase tooltip size if necessary because it may be too small on HiDPI screens
@@ -510,10 +671,39 @@ public class FlatPopupFactory
 		}
 
 		@Override
-		public void hide() {
+		public final void hide() {
+			if( disposed )
+				return;
+			disposed = true;
+
+			// immediately hide non-heavy weight popups, popup menus and combobox popups
+			// of if system property is false
+			if( !(popupWindow instanceof JWindow) || contents instanceof JPopupMenu ||
+				!FlatSystemProperties.getBoolean( FlatSystemProperties.REUSE_VISIBLE_POPUP_WINDOW, true ) )
+			{
+				hideImpl();
+				return;
+			}
+
+			// defer hiding of heavy weight popup window for an event cycle,
+			// which allows reusing popup window to avoid flicker when "moving" popup
+			((JWindow)popupWindow).getContentPane().removeAll();
+			stillShownHeavyWeightPopups.add( this );
+			EventQueue.invokeLater( () -> {
+				// hide popup if it was not reused
+				if( stillShownHeavyWeightPopups.remove( this ) )
+					hideImpl();
+			} );
+		}
+
+		void hideImpl() {
+			if( contents instanceof JComponent )
+				((JComponent)contents).putClientProperty( KEY_POPUP_USES_NATIVE_BORDER, null );
+
 			if( delegate != null ) {
 				delegate.hide();
 				delegate = null;
+				owner = null;
 				contents = null;
 			}
 
@@ -521,18 +711,54 @@ public class FlatPopupFactory
 				// restore background so that it can not affect other LaFs (when switching)
 				// because popup windows are cached and reused
 				popupWindow.setBackground( oldPopupWindowBackground );
+
+				// On macOS, popupWindow.setBackground(...) invoked from constructor,
+				// has no affect if the popup window peer (a NSWindow) is already created,
+				// which is the case when reusing a cached popup window
+				// (see class PopupFactory.HeavyWeightPopup).
+				// This may result in flicker when e.g. showing a popup in a light theme,
+				// then switching to a dark theme and again showing a popup,
+				// because the underling NSWindow still has a light background,
+				// which may be shown shortly before the actual dark popup content is shown.
+				// To fix this, dispose the popup window, which disposes the NSWindow.
+				// The AWT popup window stays in the popup cache, but when reusing it later,
+				// a new peer and a new NSWindow is created and gets the correct background.
+				if( SystemInfo.isMacOS )
+					popupWindow.dispose();
+
 				popupWindow = null;
 			}
 		}
+
+		void reset( Component contents, int ownerX, int ownerY ) {
+			// update popup window location
+			popupWindow.setLocation( ownerX, ownerY );
+
+			// replace component in content pane
+			Container contentPane = ((JWindow)popupWindow).getContentPane();
+			contentPane.removeAll();
+			contentPane.add( contents, BorderLayout.CENTER );
+			popupWindow.pack();
+
+			// update client property on contents
+			if( this.contents != contents ) {
+				Object old = (this.contents instanceof JComponent)
+					? ((JComponent)this.contents).getClientProperty( KEY_POPUP_USES_NATIVE_BORDER )
+					: null;
+				if( contents instanceof JComponent )
+					((JComponent)contents).putClientProperty( KEY_POPUP_USES_NATIVE_BORDER, old );
+
+				this.contents = contents;
+			}
+		}
 	}
 
 	//---- class DropShadowPopup ----------------------------------------------
 
 	private class DropShadowPopup
 		extends NonFlashingPopup
+		implements ComponentListener
 	{
-		private final Component owner;
-
 		// light weight
 		private JComponent lightComp;
 		private Border oldBorder;
@@ -547,11 +773,11 @@ public class FlatPopupFactory
 		// heavy weight
 		private Popup dropShadowDelegate;
 		private Window dropShadowWindow;
+		private JPanel dropShadowPanel2;
 		private Color oldDropShadowWindowBackground;
 
 		DropShadowPopup( Popup delegate, Component owner, Component contents ) {
-			super( delegate, contents );
-			this.owner = owner;
+			super( delegate, owner, contents );
 
 			Dimension size = contents.getPreferredSize();
 			if( size.width <= 0 || size.height <= 0 )
@@ -567,31 +793,31 @@ public class FlatPopupFactory
 				// the drop shadow and is positioned behind the popup window.
 
 				// create panel that paints the drop shadow
-				JPanel dropShadowPanel = new JPanel();
-				dropShadowPanel.setBorder( createDropShadowBorder() );
-				dropShadowPanel.setOpaque( false );
+				dropShadowPanel2 = new JPanel();
+				dropShadowPanel2.setBorder( createDropShadowBorder() );
+				dropShadowPanel2.setOpaque( false );
 
 				// set preferred size of drop shadow panel
 				Dimension prefSize = popupWindow.getPreferredSize();
-				Insets insets = dropShadowPanel.getInsets();
-				dropShadowPanel.setPreferredSize( new Dimension(
+				Insets insets = dropShadowPanel2.getInsets();
+				dropShadowPanel2.setPreferredSize( new Dimension(
 					prefSize.width + insets.left + insets.right,
 					prefSize.height + insets.top + insets.bottom ) );
 
 				// create heavy weight popup for drop shadow
 				int x = popupWindow.getX() - insets.left;
 				int y = popupWindow.getY() - insets.top;
-				dropShadowDelegate = getPopupForScreenOfOwner( owner, dropShadowPanel, x, y, true );
+				dropShadowDelegate = getPopupForScreenOfOwner( owner, dropShadowPanel2, x, y, true );
 
 				// make drop shadow popup window translucent
-				dropShadowWindow = SwingUtilities.windowForComponent( dropShadowPanel );
+				dropShadowWindow = SwingUtilities.windowForComponent( dropShadowPanel2 );
 				if( dropShadowWindow != null ) {
 					oldDropShadowWindowBackground = dropShadowWindow.getBackground();
 					dropShadowWindow.setBackground( new Color( 0, true ) );
 				}
 
 				// Windows 11: reset corner preference on reused heavy weight popups
-				if( isWindows11BorderSupported() ) {
+				if( SystemInfo.isWindows_11_orLater && FlatNativeWindowsLibrary.isLoaded() ) {
 					resetWindows11Border( popupWindow );
 					if( dropShadowWindow != null )
 						resetWindows11Border( dropShadowWindow );
@@ -621,6 +847,23 @@ public class FlatPopupFactory
 			}
 		}
 
+		private DropShadowPopup( DropShadowPopup reusePopup ) {
+			super( reusePopup );
+
+			// not necessary to clone fields used for light/medium weight popups
+
+			// heavy weight
+			dropShadowDelegate = reusePopup.dropShadowDelegate;
+			dropShadowWindow = reusePopup.dropShadowWindow;
+			dropShadowPanel2 = reusePopup.dropShadowPanel2;
+			oldDropShadowWindowBackground = reusePopup.oldDropShadowWindowBackground;
+		}
+
+		@Override
+		NonFlashingPopup cloneForReuse() {
+			return new DropShadowPopup( this );
+		}
+
 		private Border createDropShadowBorder() {
 			return new FlatDropShadowBorder(
 				UIManager.getColor( "Popup.dropShadowColor" ),
@@ -629,14 +872,14 @@ public class FlatPopupFactory
 		}
 
 		@Override
-		public void show() {
+		void showImpl() {
 			if( dropShadowDelegate != null )
 				showPopupAndFixLocation( dropShadowDelegate, dropShadowWindow );
 
 			if( mediumWeightPanel != null )
 				showMediumWeightDropShadow();
 
-			super.show();
+			super.showImpl();
 
 			// fix location of light weight popup in case it has left or top drop shadow
 			if( lightComp != null ) {
@@ -644,13 +887,22 @@ public class FlatPopupFactory
 				if( insets.left != 0 || insets.top != 0 )
 					lightComp.setLocation( lightComp.getX() - insets.left, lightComp.getY() - insets.top );
 			}
+
+			if( popupWindow != null ) {
+				removeAllPopupWindowComponentListeners();
+				popupWindow.addComponentListener( this );
+			}
 		}
 
 		@Override
-		public void hide() {
+		void hideImpl() {
+			if( popupWindow != null )
+				removeAllPopupWindowComponentListeners();
+
 			if( dropShadowDelegate != null ) {
 				dropShadowDelegate.hide();
 				dropShadowDelegate = null;
+				dropShadowPanel2 = null;
 			}
 
 			if( mediumWeightPanel != null ) {
@@ -659,7 +911,7 @@ public class FlatPopupFactory
 				mediumWeightPanel = null;
 			}
 
-			super.hide();
+			super.hideImpl();
 
 			if( dropShadowWindow != null ) {
 				dropShadowWindow.setBackground( oldDropShadowWindowBackground );
@@ -743,5 +995,58 @@ public class FlatPopupFactory
 			if( dropShadowPanel != null && mediumWeightPanel != null )
 				dropShadowPanel.setSize( FlatUIUtils.addInsets( mediumWeightPanel.getSize(), dropShadowPanel.getInsets() ) );
 		}
+
+		@Override
+		void reset( Component contents, int ownerX, int ownerY ) {
+			if( popupWindow != null )
+				removeAllPopupWindowComponentListeners();
+
+			super.reset( contents, ownerX, ownerY );
+
+			updateDropShadowWindowBounds();
+		}
+
+		private void updateDropShadowWindowBounds() {
+			if( dropShadowWindow == null )
+				return;
+
+			// calculate size of drop shadow window
+			Dimension size = popupWindow.getSize();
+			Insets insets = dropShadowPanel2.getInsets();
+			int w = size.width + insets.left + insets.right;
+			int h = size.height + insets.top + insets.bottom;
+
+			// update drop shadow popup window bounds
+			int x = popupWindow.getX() - insets.left;
+			int y = popupWindow.getY() - insets.top;
+			dropShadowWindow.setBounds( x, y, w, h );
+			dropShadowWindow.validate();
+		}
+
+		private void removeAllPopupWindowComponentListeners() {
+			// make sure that there is no old component listener
+			// necessary because this class is cloned if reusing popup windows
+			for( ComponentListener l : popupWindow.getComponentListeners() ) {
+				if( l instanceof DropShadowPopup )
+					popupWindow.removeComponentListener( l );
+			}
+		}
+
+		//---- interface ComponentListener ----
+
+		@Override
+		public void componentResized( ComponentEvent e ) {
+			if( e.getSource() == popupWindow )
+				updateDropShadowWindowBounds();
+		}
+
+		@Override
+		public void componentMoved( ComponentEvent e ) {
+			if( e.getSource() == popupWindow )
+				updateDropShadowWindowBounds();
+		}
+
+		@Override public void componentShown( ComponentEvent e ) {}
+		@Override public void componentHidden( ComponentEvent e ) {}
 	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatPopupMenuUI.java

@@ -239,12 +239,14 @@ public class FlatPopupMenuUI
 		if( gc == null && popupMenu.getInvoker() != null )
 			gc = popupMenu.getInvoker().getGraphicsConfiguration();
 
-		// compute screen height
+		if( gc == null )
+			return new Rectangle( Toolkit.getDefaultToolkit().getScreenSize() );
+
+		// compute screen bounds
 		// (always subtract screen insets because there is no API to detect whether
 		// the popup can overlap the taskbar; see JPopupMenu.canPopupOverlapTaskBar())
-		Toolkit toolkit = Toolkit.getDefaultToolkit();
-		Rectangle screenBounds = (gc != null) ? gc.getBounds() : new Rectangle( toolkit.getScreenSize() );
-		Insets screenInsets = Toolkit.getDefaultToolkit().getScreenInsets( gc );
+		Rectangle screenBounds = gc.getBounds();
+		Insets screenInsets = FlatUIUtils.getScreenInsets( gc );
 		return FlatUIUtils.subtractInsets( screenBounds, screenInsets );
 	}
 

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatProgressBarUI.java

@@ -18,6 +18,7 @@ package com.formdev.flatlaf.ui;
 
 import static com.formdev.flatlaf.FlatClientProperties.*;
 import java.awt.Dimension;
+import java.awt.EventQueue;
 import java.awt.FontMetrics;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
@@ -86,6 +87,17 @@ public class FlatProgressBarUI
 		installStyle();
 	}
 
+	@Override
+	public void uninstallUI( JComponent c ) {
+		if( !EventQueue.isDispatchThread() && progressBar.isIndeterminate() ) {
+			LoggingFacade.INSTANCE.logSevere(
+				"FlatLaf: Uninstalling indeterminate progress bar UI not on AWT thread may throw NPE in FlatProgressBarUI.paint(). Use SwingUtilities.invokeLater().",
+				new IllegalStateException() );
+		}
+
+		super.uninstallUI( c );
+	}
+
 	@Override
 	protected void installDefaults() {
 		super.installDefaults();
@@ -110,17 +122,25 @@ public class FlatProgressBarUI
 
 		propertyChangeListener = e -> {
 			switch( e.getPropertyName() ) {
+				case "indeterminate":
+					if( !EventQueue.isDispatchThread() && !progressBar.isIndeterminate() ) {
+						LoggingFacade.INSTANCE.logSevere(
+							"FlatLaf: Using JProgressBar.setIndeterminate(false) not on AWT thread may throw NPE in FlatProgressBarUI.paint(). Use SwingUtilities.invokeLater().",
+							new IllegalStateException() );
+					}
+					break;
+
 				case PROGRESS_BAR_LARGE_HEIGHT:
 				case PROGRESS_BAR_SQUARE:
 					progressBar.revalidate();
-					progressBar.repaint();
+					HiDPIUtils.repaint( progressBar );
 					break;
 
 				case STYLE:
 				case STYLE_CLASS:
 					installStyle();
 					progressBar.revalidate();
-					progressBar.repaint();
+					HiDPIUtils.repaint( progressBar );
 					break;
 			}
 		};
@@ -274,6 +294,6 @@ public class FlatProgressBarUI
 		// Only solution is to repaint whole progress bar.
 		double systemScaleFactor = UIScale.getSystemScaleFactor( progressBar.getGraphicsConfiguration() );
 		if( (int) systemScaleFactor != systemScaleFactor )
-			progressBar.repaint();
+			HiDPIUtils.repaint( progressBar );
 	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatRadioButtonMenuItemUI.java

@@ -23,6 +23,7 @@ import java.lang.invoke.MethodHandles;
 import java.util.Map;
 import javax.swing.Icon;
 import javax.swing.JComponent;
+import javax.swing.JMenuItem;
 import javax.swing.LookAndFeel;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.basic.BasicMenuItemUI;
@@ -102,13 +103,23 @@ public class FlatRadioButtonMenuItemUI
 		oldStyleValues = null;
 	}
 
+	@Override
+	protected void installComponents( JMenuItem menuItem ) {
+		super.installComponents( menuItem );
+
+		// update HTML renderer if necessary
+		FlatHTML.updateRendererCSSFontBaseSize( menuItem );
+	}
+
 	protected FlatMenuItemRenderer createRenderer() {
 		return new FlatMenuItemRenderer( menuItem, checkIcon, arrowIcon, acceleratorFont, acceleratorDelimiter );
 	}
 
 	@Override
 	protected PropertyChangeListener createPropertyChangeListener( JComponent c ) {
-		return FlatStylingSupport.createPropertyChangeListener( c, this::installStyle, super.createPropertyChangeListener( c ) );
+		return FlatHTML.createPropertyChangeListener(
+			FlatStylingSupport.createPropertyChangeListener( c, this::installStyle,
+				super.createPropertyChangeListener( c ) ) );
 	}
 
 	/** @since 2 */

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatRadioButtonUI.java

@@ -40,12 +40,14 @@ import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.basic.BasicButtonListener;
+import javax.swing.plaf.basic.BasicHTML;
 import javax.swing.plaf.basic.BasicRadioButtonUI;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.icons.FlatCheckBoxIcon;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
 import com.formdev.flatlaf.ui.FlatStylingSupport.UnknownStyleException;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.UIScale;
 
@@ -159,6 +161,10 @@ public class FlatRadioButtonUI
 	/** @since 2 */
 	protected void propertyChange( AbstractButton b, PropertyChangeEvent e ) {
 		switch( e.getPropertyName() ) {
+			case BasicHTML.propertyKey:
+				FlatHTML.updateRendererCSSFontBaseSize( b );
+				break;
+
 			case FlatClientProperties.STYLE:
 			case FlatClientProperties.STYLE_CLASS:
 				if( shared && FlatStylingSupport.hasStyleProperty( b ) ) {
@@ -168,7 +174,7 @@ public class FlatRadioButtonUI
 				} else
 					installStyle( b );
 				b.revalidate();
-				b.repaint();
+				HiDPIUtils.repaint( b );
 				break;
 		}
 	}
@@ -263,7 +269,7 @@ public class FlatRadioButtonUI
 
 	@Override
 	public void paint( Graphics g, JComponent c ) {
-		// fill background even if not opaque if
+		// fill background even if not opaque and if:
 		// - contentAreaFilled is true and
 		// - if background color is different to default background color
 		// (this paints selection if using the component as cell renderer)

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatRootPaneUI.java

@@ -20,6 +20,7 @@ import java.awt.Color;
 import java.awt.Component;
 import java.awt.Container;
 import java.awt.Dimension;
+import java.awt.EventQueue;
 import java.awt.Frame;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
@@ -28,11 +29,10 @@ import java.awt.Insets;
 import java.awt.LayoutManager;
 import java.awt.LayoutManager2;
 import java.awt.Window;
-import java.awt.event.ComponentAdapter;
-import java.awt.event.ComponentEvent;
 import java.awt.event.ComponentListener;
 import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
+import java.util.Objects;
 import java.util.function.Function;
 import javax.swing.JComponent;
 import javax.swing.JDialog;
@@ -41,7 +41,6 @@ import javax.swing.JLayeredPane;
 import javax.swing.JMenuBar;
 import javax.swing.JRootPane;
 import javax.swing.LookAndFeel;
-import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
 import javax.swing.border.Border;
 import javax.swing.plaf.BorderUIResource;
@@ -88,8 +87,8 @@ public class FlatRootPaneUI
 
 	private Object nativeWindowBorderData;
 	private LayoutManager oldLayout;
-	private PropertyChangeListener ancestorListener;
-	private ComponentListener componentListener;
+	private ComponentListener macFullWindowContentListener;
+	private PropertyChangeListener macWindowBackgroundListener;
 
 	public static ComponentUI createUI( JComponent c ) {
 		return new FlatRootPaneUI();
@@ -107,6 +106,7 @@ public class FlatRootPaneUI
 			installBorder();
 
 		installNativeWindowBorder();
+		macInstallFullWindowContentSupport();
 	}
 
 	protected void installBorder() {
@@ -123,6 +123,7 @@ public class FlatRootPaneUI
 
 		uninstallNativeWindowBorder();
 		uninstallClientDecorations();
+		macUninstallFullWindowContentSupport();
 		rootPane = null;
 	}
 
@@ -153,13 +154,31 @@ public class FlatRootPaneUI
 		Container parent = c.getParent();
 		if( parent instanceof JFrame || parent instanceof JDialog ) {
 			Color background = parent.getBackground();
-			if( background == null || background instanceof UIResource )
+			if( background == null || background instanceof UIResource ) {
+				if( SystemInfo.isMacOS ) {
+					// Setting window background on macOS immediately fills the whole window
+					// with that color, and slightly delayed, the Swing repaint manager
+					// repaints the actual window content. This results in some flashing
+					// when switching from a light to a dark theme (or vice versa).
+					// --> delay setting window background and immediately repaint window content
+					Runnable r = () -> {
+						parent.setBackground( UIManager.getColor( "control" ) );
+						c.paintImmediately( 0, 0, c.getWidth(), c.getHeight() );
+					};
+
+					// for class FlatAnimatedLafChange:
+					// if animated Laf change is in progress, set background color when
+					// animation has finished to avoid/reduce flashing
+					if( c.getClientProperty( "FlatLaf.internal.animatedLafChange" ) != null )
+						c.putClientProperty( "FlatLaf.internal.animatedLafChange.runWhenFinished", r );
+					else
+						EventQueue.invokeLater( r );
+				} else
 					parent.setBackground( UIManager.getColor( "control" ) );
 			}
+		}
 
-		// enable dark window appearance on macOS when running in JetBrains Runtime
-		if( SystemInfo.isJetBrainsJVM && SystemInfo.isMacOS_10_14_Mojave_orLater )
-			c.putClientProperty( "jetbrains.awt.windowDarkAppearance", FlatLaf.isLafDark() );
+		macClearBackgroundForTranslucentWindow( c );
 	}
 
 	@Override
@@ -179,55 +198,20 @@ public class FlatRootPaneUI
 	protected void installListeners( JRootPane root ) {
 		super.installListeners( root );
 
-		if( SystemInfo.isJava_9_orLater ) {
-			// On HiDPI screens, where scaling is used, there may be white lines on the
-			// bottom and on the right side of the window when it is initially shown.
-			// This is very disturbing in dark themes, but hard to notice in light themes.
-			// Seems to be a rounding issue when Swing adds dirty region of window
-			// using RepaintManager.nativeAddDirtyRegion().
-			//
-			// Note: Not using a HierarchyListener here, which would be much easier,
-			// because this causes problems with mouse clicks in heavy-weight popups.
-			// Instead, add a listener to the root pane that waits until it is added
-			// to a window, then add a component listener to the window.
-			// See: https://github.com/JFormDesigner/FlatLaf/issues/371
-			ancestorListener = e -> {
-				Object oldValue = e.getOldValue();
-				Object newValue = e.getNewValue();
-				if( newValue instanceof Window ) {
-					if( componentListener == null ) {
-						componentListener = new ComponentAdapter() {
-							@Override
-							public void componentShown( ComponentEvent e ) {
-								// add whole root pane to dirty regions when window is initially shown
-								root.getParent().repaint( root.getX(), root.getY(), root.getWidth(), root.getHeight() );
-							}
-						};
-					}
-					((Window)newValue).addComponentListener( componentListener );
-				} else if( newValue == null && oldValue instanceof Window ) {
-					if( componentListener != null )
-						((Window)oldValue).removeComponentListener( componentListener );
-				}
-			};
-			root.addPropertyChangeListener( "ancestor", ancestorListener );
-		}
+		if( SystemInfo.isMacFullWindowContentSupported )
+			macFullWindowContentListener = FullWindowContentSupport.macInstallListeners( root );
+		macInstallWindowBackgroundListener( root );
 	}
 
 	@Override
 	protected void uninstallListeners( JRootPane root ) {
 		super.uninstallListeners( root );
 
-		if( SystemInfo.isJava_9_orLater ) {
-			if( componentListener != null ) {
-				Window window = SwingUtilities.windowForComponent( root );
-				if( window != null )
-					window.removeComponentListener( componentListener );
-				componentListener = null;
-			}
-			root.removePropertyChangeListener( "ancestor", ancestorListener );
-			ancestorListener = null;
+		if( SystemInfo.isMacFullWindowContentSupported ) {
+			FullWindowContentSupport.macUninstallListeners( root, macFullWindowContentListener );
+			macFullWindowContentListener = null;
 		}
+		macUninstallWindowBackgroundListener( root );
 	}
 
 	/** @since 1.1.2 */
@@ -307,19 +291,141 @@ public class FlatRootPaneUI
 
 	// layer title pane under frame content layer to allow placing menu bar over title pane
 	protected final static Integer TITLE_PANE_LAYER = JLayeredPane.FRAME_CONTENT_LAYER - 1;
+	private final static Integer TITLE_PANE_MOUSE_LAYER = JLayeredPane.FRAME_CONTENT_LAYER - 2;
+	private final static Integer WINDOW_TOP_BORDER_LAYER = Integer.MAX_VALUE;
+
+	// for fullWindowContent mode, layer title pane over frame content layer to allow placing title bar buttons over content
+	/** @since 3.4 */
+	protected final static Integer TITLE_PANE_FULL_WINDOW_CONTENT_LAYER = JLayeredPane.FRAME_CONTENT_LAYER + 1;
+
+	private Integer getLayerForTitlePane() {
+		return isFullWindowContent( rootPane ) ? TITLE_PANE_FULL_WINDOW_CONTENT_LAYER : TITLE_PANE_LAYER;
+	}
 
 	protected void setTitlePane( FlatTitlePane newTitlePane ) {
 		JLayeredPane layeredPane = rootPane.getLayeredPane();
 
-		if( titlePane != null )
+		if( titlePane != null ) {
 			layeredPane.remove( titlePane );
+			layeredPane.remove( titlePane.mouseLayer );
+			if( titlePane.windowTopBorderLayer != null )
+				layeredPane.remove( titlePane.windowTopBorderLayer );
+		}
 
-		if( newTitlePane != null )
-			layeredPane.add( newTitlePane, TITLE_PANE_LAYER );
+		if( newTitlePane != null ) {
+			layeredPane.add( newTitlePane, getLayerForTitlePane() );
+			layeredPane.add( newTitlePane.mouseLayer, TITLE_PANE_MOUSE_LAYER );
+			if( newTitlePane.windowTopBorderLayer != null && newTitlePane.isWindowTopBorderNeeded() && isFullWindowContent( rootPane ) )
+				layeredPane.add( newTitlePane.windowTopBorderLayer, WINDOW_TOP_BORDER_LAYER );
+		}
 
 		titlePane = newTitlePane;
 	}
 
+	private void macInstallFullWindowContentSupport() {
+		if( !SystemInfo.isMacOS )
+			return;
+
+		// set window buttons spacing
+		if( isMacButtonsSpacingSupported() && rootPane.isDisplayable() ) {
+			int buttonsSpacing = FlatNativeMacLibrary.BUTTONS_SPACING_DEFAULT;
+			String value = (String) rootPane.getClientProperty( FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING );
+			if( value != null ) {
+				switch( value ) {
+					case FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING_MEDIUM:
+						buttonsSpacing = FlatNativeMacLibrary.BUTTONS_SPACING_MEDIUM;
+						break;
+
+					case FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING_LARGE:
+						buttonsSpacing = FlatNativeMacLibrary.BUTTONS_SPACING_LARGE;
+						break;
+				}
+			}
+
+			FlatNativeMacLibrary.setWindowButtonsSpacing( getParentWindow( rootPane ), buttonsSpacing );
+		}
+
+		// update buttons bounds client property
+		FullWindowContentSupport.macUpdateFullWindowContentButtonsBoundsProperty( rootPane );
+	}
+
+	private void macUninstallFullWindowContentSupport() {
+		if( !SystemInfo.isMacOS )
+			return;
+
+		// do not uninstall when switching to another FlatLaf theme
+		if( UIManager.getLookAndFeel() instanceof FlatLaf )
+			return;
+
+		// reset window buttons spacing
+		if( isMacButtonsSpacingSupported() )
+			FlatNativeMacLibrary.setWindowButtonsSpacing( getParentWindow( rootPane ), FlatNativeMacLibrary.BUTTONS_SPACING_DEFAULT );
+
+		// remove buttons bounds client property
+		FullWindowContentSupport.macUninstallFullWindowContentButtonsBoundsProperty( rootPane );
+	}
+
+	private boolean isMacButtonsSpacingSupported() {
+		return SystemInfo.isMacOS && SystemInfo.isJava_17_orLater && FlatNativeMacLibrary.isLoaded();
+	}
+
+	private void macInstallWindowBackgroundListener( JRootPane c ) {
+		if( !SystemInfo.isMacOS )
+			return;
+
+		Window window = getParentWindow( c );
+		if( window != null && macWindowBackgroundListener == null ) {
+			macWindowBackgroundListener = e -> macClearBackgroundForTranslucentWindow( c );
+			window.addPropertyChangeListener( "background", macWindowBackgroundListener );
+		}
+	}
+
+	private void macUninstallWindowBackgroundListener( JRootPane c ) {
+		if( !SystemInfo.isMacOS )
+			return;
+
+		Window window = getParentWindow( c );
+		if( window != null && macWindowBackgroundListener != null ) {
+			window.removePropertyChangeListener( "background", macWindowBackgroundListener );
+			macWindowBackgroundListener = null;
+		}
+	}
+
+	/**
+	 * When setting window background to translucent color (alpha < 255),
+	 * Swing paints that window translucent on Windows and Linux, but not on macOS.
+	 * The reason for this is that FlatLaf sets the background color of the root pane,
+	 * and Swing behaves a bit differently on macOS than on other platforms in that case.
+	 * Other L&Fs do not set root pane background, which is {@code null} by default.
+	 * <p>
+	 * To fix this problem, set the root pane background to {@code null}
+	 * if windows uses a translucent background.
+	 */
+	private void macClearBackgroundForTranslucentWindow( JRootPane c ) {
+		if( !SystemInfo.isMacOS )
+			return;
+
+		Window window = getParentWindow( c );
+		if( window != null ) {
+			Color windowBackground = window.getBackground();
+			if( windowBackground != null &&
+				windowBackground.getAlpha() < 255 &&
+				c.getBackground() instanceof UIResource )
+			{
+				// clear root pane background
+				c.setBackground( null );
+			}
+		}
+	}
+
+	private Window getParentWindow( JRootPane c ) {
+		// not using SwingUtilities.windowForComponent() or SwingUtilities.getWindowAncestor()
+		// here because root panes may be nested and used anywhere (e.g. in JInternalFrame)
+		// but we're only interested in the "root" root pane, which is a direct child of the window
+		Container parent = c.getParent();
+		return (parent instanceof Window) ? (Window) parent : null;
+	}
+
 	@Override
 	public void propertyChange( PropertyChangeEvent e ) {
 		super.propertyChange( e );
@@ -364,6 +470,33 @@ public class FlatRootPaneUI
 					titlePane.titleBarColorsChanged();
 				break;
 
+			case FlatClientProperties.TITLE_BAR_HEIGHT:
+				if( titlePane != null )
+					titlePane.revalidate();
+				break;
+
+			case FlatClientProperties.FULL_WINDOW_CONTENT:
+				if( titlePane != null ) {
+					rootPane.getLayeredPane().setLayer( titlePane, getLayerForTitlePane() );
+					if( titlePane.windowTopBorderLayer != null ) {
+						JLayeredPane layeredPane = rootPane.getLayeredPane();
+						if( titlePane.isWindowTopBorderNeeded() && isFullWindowContent( rootPane ) )
+							layeredPane.add( titlePane.windowTopBorderLayer, WINDOW_TOP_BORDER_LAYER );
+						else
+							layeredPane.remove( titlePane.windowTopBorderLayer );
+					}
+					titlePane.updateIcon();
+					titlePane.updateVisibility();
+					titlePane.updateFullWindowContentButtonsBoundsProperty();
+				}
+				FullWindowContentSupport.revalidatePlaceholders( rootPane );
+				rootPane.revalidate();
+				break;
+
+			case FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_BOUNDS:
+				FullWindowContentSupport.revalidatePlaceholders( rootPane );
+				break;
+
 			case FlatClientProperties.GLASS_PANE_FULL_HEIGHT:
 				rootPane.revalidate();
 				break;
@@ -372,14 +505,47 @@ public class FlatRootPaneUI
 				if( rootPane.isDisplayable() )
 					throw new IllegalComponentStateException( "The client property 'Window.style' must be set before the window becomes displayable." );
 				break;
+
+			case "ancestor":
+				if( e.getNewValue() instanceof Window ) {
+					if( titlePane != null && !Objects.equals( titlePane.windowStyle, FlatTitlePane.getWindowStyle( rootPane ) ) )
+						setTitlePane( createTitlePane() );
+
+					macClearBackgroundForTranslucentWindow( rootPane );
+				}
+
+				macUninstallWindowBackgroundListener( rootPane );
+				macInstallWindowBackgroundListener( rootPane );
+
+				// FlatNativeMacLibrary.setWindowButtonsSpacing() and
+				// FullWindowContentSupport.macUpdateFullWindowContentButtonsBoundsProperty()
+				// require a native window, but setting the client properties
+				// "apple.awt.fullWindowContent" or FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING
+				// is usually done before the native window is created
+				// --> try again when native window is created
+				if( e.getNewValue() instanceof Window )
+					macInstallFullWindowContentSupport();
+				break;
+
+			case FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING:
+				macInstallFullWindowContentSupport();
+				break;
+
+			case "apple.awt.fullWindowContent":
+				if( SystemInfo.isMacFullWindowContentSupported )
+					FullWindowContentSupport.macUpdateFullWindowContentButtonsBoundsProperty( rootPane );
+				break;
 		}
 	}
 
+	/** @since 3.4 */
+	protected static boolean isFullWindowContent( JRootPane rootPane ) {
+		return FlatClientProperties.clientPropertyBoolean( rootPane, FlatClientProperties.FULL_WINDOW_CONTENT, false );
+	}
+
 	protected static boolean isMenuBarEmbedded( JRootPane rootPane ) {
-		RootPaneUI ui = rootPane.getUI();
-		return ui instanceof FlatRootPaneUI &&
-			((FlatRootPaneUI)ui).titlePane != null &&
-			((FlatRootPaneUI)ui).titlePane.isMenuBarEmbedded();
+		FlatTitlePane titlePane = getTitlePane( rootPane );
+		return titlePane != null && titlePane.isMenuBarEmbedded();
 	}
 
 	/** @since 2.4 */
@@ -415,24 +581,22 @@ public class FlatRootPaneUI
 		private Dimension computeLayoutSize( Container parent, Function<Component, Dimension> getSizeFunc ) {
 			JRootPane rootPane = (JRootPane) parent;
 
-			Dimension titlePaneSize = (titlePane != null)
-				? getSizeFunc.apply( titlePane )
-				: new Dimension();
 			Dimension contentSize = (rootPane.getContentPane() != null)
 				? getSizeFunc.apply( rootPane.getContentPane() )
-				: rootPane.getSize();
+				: rootPane.getSize(); // same as in JRootPane.RootLayout.preferredLayoutSize()
 
 			int width = contentSize.width; // title pane width is not considered here
-			int height = titlePaneSize.height + contentSize.height;
+			int height = contentSize.height;
+			if( titlePane != null && !isFullWindowContent( rootPane ) )
+				height += getSizeFunc.apply( titlePane ).height;
 			if( titlePane == null || !titlePane.isMenuBarEmbedded() ) {
 				JMenuBar menuBar = rootPane.getJMenuBar();
-				Dimension menuBarSize = (menuBar != null && menuBar.isVisible())
-					? getSizeFunc.apply( menuBar )
-					: new Dimension();
-
+				if( menuBar != null && menuBar.isVisible() ) {
+					Dimension menuBarSize = getSizeFunc.apply( menuBar );
 					width = Math.max( width, menuBarSize.width );
 					height += menuBarSize.height;
 				}
+			}
 
 			Insets insets = rootPane.getInsets();
 
@@ -456,11 +620,28 @@ public class FlatRootPaneUI
 			if( rootPane.getLayeredPane() != null )
 				rootPane.getLayeredPane().setBounds( x, y, width, height );
 
-			// title pane
+			// title pane (is a child of layered pane)
 			int nextY = 0;
 			if( titlePane != null ) {
 				int prefHeight = !isFullScreen ? titlePane.getPreferredSize().height : 0;
+				boolean isFullWindowContent = isFullWindowContent( rootPane );
+				if( isFullWindowContent && !UIManager.getBoolean( FlatTitlePane.KEY_DEBUG_SHOW_RECTANGLES ) ) {
+					// place title bar into top-right corner
+					int tw = Math.min( titlePane.getPreferredSize().width, width );
+					int tx = titlePane.getComponentOrientation().isLeftToRight() ? width - tw : 0;
+					titlePane.setBounds( tx, 0, tw, prefHeight );
+				} else
 					titlePane.setBounds( 0, 0, width, prefHeight );
+
+				titlePane.mouseLayer.setBounds( 0, 0, width, prefHeight );
+				if( titlePane.windowTopBorderLayer != null ) {
+					boolean show = isFullWindowContent && !titlePane.isWindowMaximized() && !isFullScreen;
+					if( show )
+						titlePane.windowTopBorderLayer.setBounds( 0, 0, width, 1 );
+					titlePane.windowTopBorderLayer.setVisible( show );
+				}
+
+				if( !isFullWindowContent )
 					nextY += prefHeight;
 			}
 
@@ -472,7 +653,7 @@ public class FlatRootPaneUI
 				rootPane.getGlassPane().setBounds( x, y + offset, width, height - offset );
 			}
 
-			// menu bar
+			// menu bar (is a child of layered pane)
 			JMenuBar menuBar = rootPane.getJMenuBar();
 			if( menuBar != null && menuBar.isVisible() ) {
 				boolean embedded = !isFullScreen && titlePane != null && titlePane.isMenuBarEmbedded();
@@ -480,13 +661,23 @@ public class FlatRootPaneUI
 					titlePane.validate();
 					menuBar.setBounds( titlePane.getMenuBarBounds() );
 				} else {
+					int mx = 0;
+					int mw = width;
+					if( titlePane != null && isFullWindowContent( rootPane ) ) {
+						// make menu bar width smaller to avoid that it overlaps title bar buttons
+						int tw = Math.min( titlePane.getPreferredSize().width, width );
+						mw -= tw;
+						if( !titlePane.getComponentOrientation().isLeftToRight() )
+							mx = tw;
+					}
+
 					Dimension prefSize = menuBar.getPreferredSize();
-					menuBar.setBounds( 0, nextY, width, prefSize.height );
+					menuBar.setBounds( mx, nextY, mw, prefSize.height );
 					nextY += prefSize.height;
 				}
 			}
 
-			// content pane
+			// content pane (is a child of layered pane)
 			Container contentPane = rootPane.getContentPane();
 			if( contentPane != null )
 				contentPane.setBounds( 0, nextY, width, Math.max( height - nextY, 0 ) );
@@ -499,7 +690,7 @@ public class FlatRootPaneUI
 		@Override
 		public void invalidateLayout( Container parent ) {
 			if( titlePane != null )
-				titlePane.menuBarChanged();
+				titlePane.menuBarInvalidate();
 		}
 
 		@Override
@@ -519,7 +710,7 @@ public class FlatRootPaneUI
 	 * Window border used for non-native window decorations.
 	 */
 	public static class FlatWindowBorder
-		extends BorderUIResource.EmptyBorderUIResource
+		extends FlatEmptyBorder
 	{
 		protected final Color activeBorderColor = UIManager.getColor( "RootPane.activeBorderColor" );
 		protected final Color inactiveBorderColor = UIManager.getColor( "RootPane.inactiveBorderColor" );
@@ -552,7 +743,10 @@ public class FlatRootPaneUI
 		}
 
 		private void paintImpl( Graphics2D g, int x, int y, int width, int height, double scaleFactor ) {
-			g.drawRect( x, y, width - 1, height - 1 );
+			Object[] oldRenderingHints = FlatUIUtils.setRenderingHints( g );
+			float lineWidth = (float) (UIScale.scale( 1f ) * scaleFactor);
+			g.fill( FlatUIUtils.createRectangle( x, y, width, height, lineWidth ) );
+			FlatUIUtils.resetRenderingHints( g, oldRenderingHints );
 		}
 
 		protected boolean isWindowMaximized( Component c ) {

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatScrollBarUI.java

@@ -43,6 +43,7 @@ import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableField;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableLookupProvider;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.SystemInfo;
 import com.formdev.flatlaf.util.UIScale;
@@ -212,14 +213,14 @@ public class FlatScrollBarUI
 			switch( e.getPropertyName() ) {
 				case FlatClientProperties.SCROLL_BAR_SHOW_BUTTONS:
 					scrollbar.revalidate();
-					scrollbar.repaint();
+					HiDPIUtils.repaint( scrollbar );
 					break;
 
 				case FlatClientProperties.STYLE:
 				case FlatClientProperties.STYLE_CLASS:
 					installStyle();
 					scrollbar.revalidate();
-					scrollbar.repaint();
+					HiDPIUtils.repaint( scrollbar );
 					break;
 
 				case "componentOrientation":
@@ -245,7 +246,7 @@ public class FlatScrollBarUI
 								// because scroll bars do not receive mouse exited event.
 								// The scroll pane, including its scroll bars, is not part
 								// of the component hierarchy and does not receive mouse events
-								// directly. Instead LWComponentPeer receives mouse events
+								// directly. Instead, LWComponentPeer receives mouse events
 								// and delegates them to peers, but entered/exited events
 								// are sent only for the whole scroll pane.
 								// Exited event is only sent when mouse leaves scroll pane.
@@ -492,7 +493,7 @@ public class FlatScrollBarUI
 
 		private void repaint() {
 			if( scrollbar.isEnabled() )
-				scrollbar.repaint();
+				HiDPIUtils.repaint( scrollbar );
 		}
 	}
 

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatScrollPaneBorder.java

@@ -0,0 +1,118 @@
+/*
+ * Copyright 2023 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.ui;
+
+import java.awt.Component;
+import java.awt.Insets;
+import javax.swing.JList;
+import javax.swing.JScrollPane;
+import javax.swing.JTable;
+import javax.swing.JTree;
+import javax.swing.UIManager;
+import javax.swing.text.JTextComponent;
+import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
+import com.formdev.flatlaf.util.UIScale;
+
+/**
+ * Border for {@link javax.swing.JScrollPane}.
+ *
+ * @uiDefault ScrollPane.arc				int
+ * @uiDefault ScrollPane.List.arc			int
+ * @uiDefault ScrollPane.Table.arc			int
+ * @uiDefault ScrollPane.TextComponent.arc	int
+ * @uiDefault ScrollPane.Tree.arc			int
+
+ * @author Karl Tauber
+ * @since 3.3
+ */
+public class FlatScrollPaneBorder
+	extends FlatBorder
+{
+	@Styleable protected int arc = UIManager.getInt( "ScrollPane.arc" );
+
+	private boolean isArcStyled;
+	private final int listArc = FlatUIUtils.getUIInt( "ScrollPane.List.arc", -1 );
+	private final int tableArc = FlatUIUtils.getUIInt( "ScrollPane.Table.arc", -1 );
+	private final int textComponentArc = FlatUIUtils.getUIInt( "ScrollPane.TextComponent.arc", -1 );
+	private final int treeArc = FlatUIUtils.getUIInt( "ScrollPane.Tree.arc", -1 );
+
+	@Override
+	public Object applyStyleProperty( String key, Object value ) {
+		Object oldValue = super.applyStyleProperty( key, value );
+
+		if( "arc".equals( key ) )
+			isArcStyled = true;
+
+		return oldValue;
+	}
+
+	@Override
+	public Insets getBorderInsets( Component c, Insets insets ) {
+		insets = super.getBorderInsets( c, insets );
+
+		// if view is rounded, increase left and right insets to avoid that the viewport
+		// is painted over the rounded border on the corners
+		int padding = getLeftRightPadding( c );
+		if( padding > 0 ) {
+			insets.left += padding;
+			insets.right += padding;
+		}
+
+		return insets;
+	}
+
+	@Override
+	protected int getArc( Component c ) {
+		if( isCellEditor( c ) )
+			return 0;
+
+		if( isArcStyled )
+			return arc;
+
+		if( c instanceof JScrollPane ) {
+			Component view = FlatScrollPaneUI.getView( (JScrollPane) c );
+			if( listArc >= 0 && view instanceof JList )
+				return listArc;
+			if( tableArc >= 0 && view instanceof JTable )
+				return tableArc;
+			if( textComponentArc >= 0&& view instanceof JTextComponent )
+				return textComponentArc;
+			if( treeArc >= 0 && view instanceof JTree )
+				return treeArc;
+		}
+
+		return arc;
+	}
+
+	/**
+	 * Returns the scaled left/right padding used when arc is larger than zero.
+	 * <p>
+	 * This is the distance from the inside of the left border to the left side of the view component.
+	 * On the right side, this is the distance between the right side of the view component and
+	 * the vertical scrollbar. Or the inside of the right border if the scrollbar is hidden.
+	 */
+	public int getLeftRightPadding( Component c ) {
+		// Subtract lineWidth from radius because radius is given for the outside
+		// of the painted line, but insets from super already include lineWidth.
+		// Reduce padding by 10% to make padding slightly smaller because it is not recognizable
+		// when the view is minimally painted over the beginning of the border curve.
+		int arc = getArc( c );
+		return (arc > 0)
+			? Math.max( Math.round( UIScale.scale( ((arc / 2f) - getLineWidth( c )) * 0.9f ) ), 0 )
+			: 0;
+	}
+}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatScrollPaneUI.java

@@ -17,9 +17,12 @@
 package com.formdev.flatlaf.ui;
 
 import java.awt.Component;
+import java.awt.Container;
 import java.awt.Graphics;
+import java.awt.Graphics2D;
 import java.awt.Insets;
 import java.awt.KeyboardFocusManager;
+import java.awt.LayoutManager;
 import java.awt.Rectangle;
 import java.awt.event.ContainerEvent;
 import java.awt.event.ContainerListener;
@@ -41,16 +44,20 @@ import javax.swing.JTree;
 import javax.swing.JViewport;
 import javax.swing.LookAndFeel;
 import javax.swing.ScrollPaneConstants;
+import javax.swing.ScrollPaneLayout;
 import javax.swing.Scrollable;
 import javax.swing.SwingConstants;
 import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
+import javax.swing.border.Border;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.basic.BasicScrollPaneUI;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
+import com.formdev.flatlaf.util.UIScale;
 
 /**
  * Provides the Flat LaF UI delegate for {@link javax.swing.JScrollPane}.
@@ -97,7 +104,13 @@ public class FlatScrollPaneUI
 		super.installUI( c );
 
 		int focusWidth = UIManager.getInt( "Component.focusWidth" );
-		LookAndFeel.installProperty( c, "opaque", focusWidth == 0 );
+		int arc = UIManager.getInt( "ScrollPane.arc" );
+		LookAndFeel.installProperty( c, "opaque", focusWidth == 0 && arc == 0 );
+
+		// install layout manager
+		LayoutManager layout = c.getLayout();
+		if( layout != null && layout.getClass() == ScrollPaneLayout.UIResource.class )
+			c.setLayout( createScrollPaneLayout() );
 
 		installStyle();
 
@@ -108,6 +121,10 @@ public class FlatScrollPaneUI
 	public void uninstallUI( JComponent c ) {
 		MigLayoutVisualPadding.uninstall( scrollpane );
 
+		// uninstall layout manager
+		if( c.getLayout() instanceof FlatScrollPaneLayout )
+			c.setLayout( new ScrollPaneLayout.UIResource() );
+
 		super.uninstallUI( c );
 
 		oldStyleValues = null;
@@ -130,6 +147,13 @@ public class FlatScrollPaneUI
 		handler = null;
 	}
 
+	/**
+	 * @since 3.3
+	 */
+	protected FlatScrollPaneLayout createScrollPaneLayout() {
+		return new FlatScrollPaneLayout();
+	}
+
 	@Override
 	protected MouseWheelListener createMouseWheelListener() {
 		MouseWheelListener superListener = super.createMouseWheelListener();
@@ -186,7 +210,7 @@ public class FlatScrollPaneUI
 
 			// Use (0, 0) view position to obtain a constant unit increment of first item.
 			// Unit increment may be different for each item.
-			Rectangle visibleRect = new Rectangle( viewport.getViewSize() );
+			Rectangle visibleRect = new Rectangle( viewport.getExtentSize() );
 			unitIncrement = scrollable.getScrollableUnitIncrement( visibleRect, orientation, 1 );
 
 			if( unitIncrement > 0 ) {
@@ -274,11 +298,11 @@ public class FlatScrollPaneUI
 					JScrollBar hsb = scrollpane.getHorizontalScrollBar();
 					if( vsb != null ) {
 						vsb.revalidate();
-						vsb.repaint();
+						HiDPIUtils.repaint( vsb );
 					}
 					if( hsb != null ) {
 						hsb.revalidate();
-						hsb.repaint();
+						HiDPIUtils.repaint( hsb );
 					}
 					break;
 
@@ -290,8 +314,7 @@ public class FlatScrollPaneUI
 					Object corner = e.getNewValue();
 					if( corner instanceof JButton &&
 						((JButton)corner).getBorder() instanceof FlatButtonBorder &&
-						scrollpane.getViewport() != null &&
-						scrollpane.getViewport().getView() instanceof JTable )
+						getView( scrollpane ) instanceof JTable )
 					{
 						((JButton)corner).setBorder( BorderFactory.createEmptyBorder() );
 						((JButton)corner).setFocusable( false );
@@ -299,14 +322,26 @@ public class FlatScrollPaneUI
 					break;
 
 				case FlatClientProperties.OUTLINE:
-					scrollpane.repaint();
+					HiDPIUtils.repaint( scrollpane );
 					break;
 
 				case FlatClientProperties.STYLE:
 				case FlatClientProperties.STYLE_CLASS:
 					installStyle();
 					scrollpane.revalidate();
-					scrollpane.repaint();
+					HiDPIUtils.repaint( scrollpane );
+					break;
+
+				case "border":
+					Object newBorder = e.getNewValue();
+					if( newBorder != null && newBorder == UIManager.getBorder( "Table.scrollPaneBorder" ) ) {
+						// JTable.configureEnclosingScrollPaneUI() replaces the scrollpane border
+						// with another one --> re-apply style on new border
+						borderShared = null;
+						installStyle();
+						scrollpane.revalidate();
+						HiDPIUtils.repaint( scrollpane );
+					}
 					break;
 			}
 		};
@@ -334,9 +369,10 @@ public class FlatScrollPaneUI
 
 	/** @since 2 */
 	protected Object applyStyleProperty( String key, Object value ) {
-		if( key.equals( "focusWidth" ) ) {
+		if( key.equals( "focusWidth" ) || key.equals( "arc" ) ) {
 			int focusWidth = (value instanceof Integer) ? (int) value : UIManager.getInt( "Component.focusWidth" );
-			LookAndFeel.installProperty( scrollpane, "opaque", focusWidth == 0 );
+			int arc = (value instanceof Integer) ? (int) value : UIManager.getInt( "ScrollPane.arc" );
+			LookAndFeel.installProperty( scrollpane, "opaque", focusWidth == 0 && arc == 0 );
 		}
 
 		if( borderShared == null )
@@ -402,13 +438,46 @@ public class FlatScrollPaneUI
 				c.getHeight() - insets.top - insets.bottom );
 		}
 
+		// if view is rounded, paint rounded background with view background color
+		// to ensure that free areas at left and right have same color as view
+		Component view;
+		float arc = getBorderArc( scrollpane );
+		if( arc > 0 && (view = getView( scrollpane )) != null ) {
+			float focusWidth = FlatUIUtils.getBorderFocusWidth( c );
+
+			g.setColor( view.getBackground() );
+
+			Object[] oldRenderingHints = FlatUIUtils.setRenderingHints( g );
+			FlatUIUtils.paintComponentBackground( (Graphics2D) g, 0, 0, c.getWidth(), c.getHeight(), focusWidth, arc );
+			FlatUIUtils.resetRenderingHints( g, oldRenderingHints );
+		}
+
 		paint( g, c );
 	}
 
+	@Override
+	public void paint( Graphics g, JComponent c ) {
+		Border viewportBorder = scrollpane.getViewportBorder();
+		if( viewportBorder != null ) {
+			Rectangle r = scrollpane.getViewportBorderBounds();
+			int padding = getBorderLeftRightPadding( scrollpane );
+			JScrollBar vsb = scrollpane.getVerticalScrollBar();
+			if( padding > 0 &&
+				vsb != null && vsb.isVisible() &&
+				scrollpane.getLayout() instanceof FlatScrollPaneLayout &&
+				((FlatScrollPaneLayout)scrollpane.getLayout()).canIncreaseViewportWidth( scrollpane ) )
+			{
+				boolean ltr = scrollpane.getComponentOrientation().isLeftToRight();
+				int extraWidth = Math.min( padding, vsb.getWidth() );
+				viewportBorder.paintBorder( scrollpane, g, r.x - (ltr ? 0 : extraWidth), r.y, r.width + extraWidth, r.height );
+			} else
+				viewportBorder.paintBorder( scrollpane, g, r.x, r.y, r.width, r.height );
+		}
+	}
+
 	/** @since 1.3 */
 	public static boolean isPermanentFocusOwner( JScrollPane scrollPane ) {
-		JViewport viewport = scrollPane.getViewport();
-		Component view = (viewport != null) ? viewport.getView() : null;
+		Component view = getView( scrollPane );
 		if( view == null )
 			return false;
 
@@ -428,6 +497,25 @@ public class FlatScrollPaneUI
 		return false;
 	}
 
+	static Component getView( JScrollPane scrollPane ) {
+		JViewport viewport = scrollPane.getViewport();
+		return (viewport != null) ? viewport.getView() : null;
+	}
+
+	private static float getBorderArc( JScrollPane scrollPane ) {
+		Border border = scrollPane.getBorder();
+		return (border instanceof FlatScrollPaneBorder)
+			? UIScale.scale( (float) ((FlatScrollPaneBorder)border).getArc( scrollPane ) )
+			: 0;
+	}
+
+	private static int getBorderLeftRightPadding( JScrollPane scrollPane ) {
+		Border border = scrollPane.getBorder();
+		return (border instanceof FlatScrollPaneBorder)
+			? ((FlatScrollPaneBorder)border).getLeftRightPadding( scrollPane )
+			: 0;
+	}
+
 	//---- class Handler ------------------------------------------------------
 
 	/**
@@ -450,13 +538,71 @@ public class FlatScrollPaneUI
 		@Override
 		public void focusGained( FocusEvent e ) {
 			// necessary to update focus border
-			scrollpane.repaint();
+			if( scrollpane.getBorder() instanceof FlatBorder )
+				HiDPIUtils.repaint( scrollpane );
 		}
 
 		@Override
 		public void focusLost( FocusEvent e ) {
 			// necessary to update focus border
-			scrollpane.repaint();
+			if( scrollpane.getBorder() instanceof FlatBorder )
+				HiDPIUtils.repaint( scrollpane );
+		}
+	}
+
+	//---- class FlatScrollPaneLayout -----------------------------------------
+
+	/**
+	 * @since 3.3
+	 */
+	protected static class FlatScrollPaneLayout
+		extends ScrollPaneLayout.UIResource
+	{
+		@Override
+		public void layoutContainer( Container parent ) {
+			super.layoutContainer( parent );
+
+			JScrollPane scrollPane = (JScrollPane) parent;
+			int padding = getBorderLeftRightPadding( scrollPane );
+			if( padding > 0 && vsb != null && vsb.isVisible() ) {
+				// move vertical scrollbar to trailing edge
+				Insets insets = scrollPane.getInsets();
+				Rectangle r = vsb.getBounds();
+				int y = Math.max( r.y, insets.top + padding );
+				int y2 = Math.min( r.y + r.height, scrollPane.getHeight() - insets.bottom - padding );
+				boolean ltr = scrollPane.getComponentOrientation().isLeftToRight();
+
+				vsb.setBounds( r.x + (ltr ? padding : -padding), y, r.width, y2 - y );
+
+				// increase width of viewport, column header and horizontal scrollbar
+				if( canIncreaseViewportWidth( scrollPane ) ) {
+					int extraWidth = Math.min( padding, vsb.getWidth() );
+					resizeViewport( viewport, extraWidth, ltr );
+					resizeViewport( colHead, extraWidth, ltr );
+					resizeViewport( hsb, extraWidth, ltr );
+				}
+			}
+		}
+
+		boolean canIncreaseViewportWidth( JScrollPane scrollPane ) {
+			return scrollPane.getComponentOrientation().isLeftToRight()
+				? !isCornerVisible( upperRight ) && !isCornerVisible( lowerRight )
+				: !isCornerVisible( upperLeft ) && !isCornerVisible( lowerLeft );
+		}
+
+		private static boolean isCornerVisible( Component corner ) {
+			return corner != null &&
+				corner.getWidth() > 0 &&
+				corner.getHeight() > 0 &&
+				corner.isVisible();
+		}
+
+		private static void resizeViewport( Component c, int extraWidth, boolean ltr ) {
+			if( c == null )
+				return;
+
+			Rectangle vr = c.getBounds();
+			c.setBounds( vr.x - (ltr ? 0 : extraWidth), vr.y, vr.width + extraWidth, vr.height );
 		}
 	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatSeparatorUI.java

@@ -32,6 +32,7 @@ import javax.swing.plaf.basic.BasicSeparatorUI;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
 
 /**
@@ -134,7 +135,7 @@ public class FlatSeparatorUI
 				} else
 					installStyle( s );
 				s.revalidate();
-				s.repaint();
+				HiDPIUtils.repaint( s );
 				break;
 		}
 	}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatSliderUI.java

@@ -25,6 +25,8 @@ import java.awt.Graphics2D;
 import java.awt.Insets;
 import java.awt.Rectangle;
 import java.awt.Shape;
+import java.awt.event.FocusEvent;
+import java.awt.event.FocusListener;
 import java.awt.event.MouseEvent;
 import java.awt.geom.Ellipse2D;
 import java.awt.geom.Path2D;
@@ -191,6 +193,23 @@ public class FlatSliderUI
 		return new FlatTrackListener();
 	}
 
+	@Override
+	protected FocusListener createFocusListener( JSlider slider ) {
+		return new BasicSliderUI.FocusHandler() {
+			@Override
+			public void focusGained( FocusEvent e ) {
+				super.focusGained( e );
+				HiDPIUtils.repaint( slider );
+			}
+
+			@Override
+			public void focusLost( FocusEvent e ) {
+				super.focusLost( e );
+				HiDPIUtils.repaint( slider );
+			}
+		};
+	}
+
 	@Override
 	protected PropertyChangeListener createPropertyChangeListener( JSlider slider ) {
 		return FlatStylingSupport.createPropertyChangeListener( slider, this::installStyle,
@@ -422,7 +441,7 @@ debug*/
 		Color thumbColor, Color thumbBorderColor, Color focusedColor, float thumbBorderWidth, int focusWidth )
 	{
 		double systemScaleFactor = UIScale.getSystemScaleFactor( (Graphics2D) g );
-		if( systemScaleFactor != 1 && systemScaleFactor != 2 ) {
+		if( systemScaleFactor != (int) systemScaleFactor ) {
 			// paint at scale 1x to avoid clipping on right and bottom edges at 125%, 150% or 175%
 			HiDPIUtils.paintAtScale1x( (Graphics2D) g, thumbRect.x, thumbRect.y, thumbRect.width, thumbRect.height,
 				(g2d, x2, y2, width2, height2, scaleFactor) -> {
@@ -579,15 +598,15 @@ debug*/
 
 	@Override
 	public void setThumbLocation( int x, int y ) {
-		if( !isRoundThumb() ) {
-			// the needle of the directional thumb is painted outside of thumbRect
-			// --> must increase repaint rectangle
-
 		// set new thumb location and compute union of old and new thumb bounds
 		Rectangle r = new Rectangle( thumbRect );
 		thumbRect.setLocation( x, y );
 		SwingUtilities.computeUnion( thumbRect.x, thumbRect.y, thumbRect.width, thumbRect.height, r );
 
+		if( !isRoundThumb() ) {
+			// the needle of the directional thumb is painted outside of thumbRect
+			// --> must increase repaint rectangle
+
 			// increase union rectangle for repaint
 			int extra = (int) Math.ceil( UIScale.scale( focusWidth ) * 0.4142f );
 			if( slider.getOrientation() == JSlider.HORIZONTAL )
@@ -597,10 +616,9 @@ debug*/
 				if( !slider.getComponentOrientation().isLeftToRight() )
 					r.x -= extra;
 			}
+		}
 
-			slider.repaint( r );
-		} else
-			super.setThumbLocation( x, y );
+		HiDPIUtils.repaint( slider, r );
 	}
 
 	//---- class FlatTrackListener --------------------------------------------
@@ -688,21 +706,21 @@ debug*/
 				!UIManager.getBoolean( "Slider.snapToTicksOnReleased" ) )
 			{
 				calculateThumbLocation();
-				slider.repaint();
+				HiDPIUtils.repaint( slider );
 			}
 		}
 
 		protected void setThumbHover( boolean hover ) {
 			if( hover != thumbHover ) {
 				thumbHover = hover;
-				slider.repaint( thumbRect );
+				HiDPIUtils.repaint( slider, thumbRect );
 			}
 		}
 
 		protected void setThumbPressed( boolean pressed ) {
 			if( pressed != thumbPressed ) {
 				thumbPressed = pressed;
-				slider.repaint( thumbRect );
+				HiDPIUtils.repaint( slider, thumbRect );
 			}
 		}
 

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatSpinnerUI.java

@@ -47,6 +47,7 @@ import javax.swing.plaf.basic.BasicSpinnerUI;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
 
 /**
@@ -139,8 +140,6 @@ public class FlatSpinnerUI
 		buttonHoverArrowColor = UIManager.getColor( "Spinner.buttonHoverArrowColor" );
 		buttonPressedArrowColor = UIManager.getColor( "Spinner.buttonPressedArrowColor" );
 		padding = UIManager.getInsets( "Spinner.padding" );
-
-		MigLayoutVisualPadding.install( spinner );
 	}
 
 	@Override
@@ -161,8 +160,6 @@ public class FlatSpinnerUI
 
 		oldStyleValues = null;
 		borderShared = null;
-
-		MigLayoutVisualPadding.uninstall( spinner );
 	}
 
 	@Override
@@ -172,6 +169,8 @@ public class FlatSpinnerUI
 		addEditorFocusListener( spinner.getEditor() );
 		spinner.addFocusListener( getHandler() );
 		spinner.addPropertyChangeListener( getHandler() );
+
+		MigLayoutVisualPadding.install( spinner );
 	}
 
 	@Override
@@ -183,6 +182,8 @@ public class FlatSpinnerUI
 		spinner.removePropertyChangeListener( getHandler() );
 
 		handler = null;
+
+		MigLayoutVisualPadding.uninstall( spinner );
 	}
 
 	private Handler getHandler() {
@@ -586,7 +587,7 @@ public class FlatSpinnerUI
 		@Override
 		public void focusGained( FocusEvent e ) {
 			// necessary to update focus border
-			spinner.repaint();
+			HiDPIUtils.repaint( spinner );
 
 			// if spinner gained focus, transfer it to the editor text field
 			if( e.getComponent() == spinner ) {
@@ -599,7 +600,7 @@ public class FlatSpinnerUI
 		@Override
 		public void focusLost( FocusEvent e ) {
 			// necessary to update focus border
-			spinner.repaint();
+			HiDPIUtils.repaint( spinner );
 		}
 
 		//---- interface PropertyChangeListener ----
@@ -614,7 +615,7 @@ public class FlatSpinnerUI
 
 				case FlatClientProperties.COMPONENT_ROUND_RECT:
 				case FlatClientProperties.OUTLINE:
-					spinner.repaint();
+					HiDPIUtils.repaint( spinner );
 					break;
 
 				case FlatClientProperties.MINIMUM_WIDTH:
@@ -625,7 +626,7 @@ public class FlatSpinnerUI
 				case FlatClientProperties.STYLE_CLASS:
 					installStyle();
 					spinner.revalidate();
-					spinner.repaint();
+					HiDPIUtils.repaint( spinner );
 					break;
 			}
 		}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatSplitPaneUI.java

@@ -16,7 +16,9 @@
 
 package com.formdev.flatlaf.ui;
 
+import java.awt.Canvas;
 import java.awt.Color;
+import java.awt.Component;
 import java.awt.Container;
 import java.awt.Cursor;
 import java.awt.Graphics;
@@ -67,6 +69,8 @@ import com.formdev.flatlaf.util.UIScale;
  * <!-- FlatSplitPaneUI -->
  *
  * @uiDefault Component.arrowType						String	chevron (default) or triangle
+ * @uiDefault SplitPaneDivider.hoverColor				Color	optional
+ * @uiDefault SplitPaneDivider.pressedColor				Color	optional
  * @uiDefault SplitPaneDivider.oneTouchArrowColor		Color
  * @uiDefault SplitPaneDivider.oneTouchHoverArrowColor	Color
  * @uiDefault SplitPaneDivider.oneTouchPressedArrowColor Color
@@ -80,9 +84,10 @@ import com.formdev.flatlaf.util.UIScale;
  */
 public class FlatSplitPaneUI
 	extends BasicSplitPaneUI
-	implements StyleableUI
+	implements StyleableUI, FlatTitlePane.TitleBarCaptionHitTest
 {
 	@Styleable protected String arrowType;
+	/** @since 3.3 */ @Styleable protected Color draggingColor;
 	@Styleable protected Color oneTouchArrowColor;
 	@Styleable protected Color oneTouchHoverArrowColor;
 	@Styleable protected Color oneTouchPressedArrowColor;
@@ -104,6 +109,8 @@ public class FlatSplitPaneUI
 	protected void installDefaults() {
 		arrowType = UIManager.getString( "Component.arrowType" );
 
+		draggingColor = UIManager.getColor( "SplitPaneDivider.draggingColor" );
+
 		// get one-touch colors before invoking super.installDefaults() because they are
 		// used in there on LaF switching
 		oneTouchArrowColor = UIManager.getColor( "SplitPaneDivider.oneTouchArrowColor" );
@@ -117,6 +124,8 @@ public class FlatSplitPaneUI
 	protected void uninstallDefaults() {
 		super.uninstallDefaults();
 
+		draggingColor = null;
+
 		oneTouchArrowColor = null;
 		oneTouchHoverArrowColor = null;
 		oneTouchPressedArrowColor = null;
@@ -183,12 +192,58 @@ public class FlatSplitPaneUI
 		return FlatStylingSupport.getAnnotatedStyleableValue( this, key );
 	}
 
+	@Override
+	protected Component createDefaultNonContinuousLayoutDivider() {
+		// only used for non-continuous layout if left or right component is heavy weight
+		return new Canvas() {
+			@Override
+			public void paint( Graphics g ) {
+				if( !isContinuousLayout() && getLastDragLocation() != -1 )
+					paintDragDivider( g, 0 );
+			}
+		};
+	}
+
+	@Override
+	public void finishedPaintingChildren( JSplitPane sp, Graphics g ) {
+		if( sp == splitPane && getLastDragLocation() != -1 && !isContinuousLayout() && !draggingHW )
+			paintDragDivider( g, getLastDragLocation() );
+	}
+
+	private void paintDragDivider( Graphics g, int dividerLocation ) {
+		// divider bounds
+		boolean horizontal = (getOrientation() == JSplitPane.HORIZONTAL_SPLIT);
+		int x = horizontal ? dividerLocation : 0;
+		int y = !horizontal ? dividerLocation : 0;
+		int width = horizontal ? dividerSize : splitPane.getWidth();
+		int height = !horizontal ? dividerSize : splitPane.getHeight();
+
+		// paint background
+		g.setColor( FlatUIUtils.deriveColor( draggingColor, splitPane.getBackground() ) );
+		g.fillRect( x, y, width, height );
+
+		// paint divider style (e.g. grip)
+		if( divider instanceof FlatSplitPaneDivider )
+			((FlatSplitPaneDivider)divider).paintStyle( g, x, y, width, height );
+	}
+
+	//---- interface FlatTitlePane.TitleBarCaptionHitTest ----
+
+	/** @since 3.4 */
+	@Override
+	public Boolean isTitleBarCaptionAt( int x, int y ) {
+		// necessary because BasicSplitPaneDivider adds some mouse listeners for dragging divider
+		return null; // check children
+	}
+
 	//---- class FlatSplitPaneDivider -----------------------------------------
 
 	protected class FlatSplitPaneDivider
 		extends BasicSplitPaneDivider
 	{
 		@Styleable protected String style = UIManager.getString( "SplitPaneDivider.style" );
+		/** @since 3.3 */ @Styleable protected Color hoverColor = UIManager.getColor( "SplitPaneDivider.hoverColor" );
+		/** @since 3.3 */ @Styleable protected Color pressedColor = UIManager.getColor( "SplitPaneDivider.pressedColor" );
 		@Styleable protected Color gripColor = UIManager.getColor( "SplitPaneDivider.gripColor" );
 		@Styleable protected int gripDotCount = FlatUIUtils.getUIInt( "SplitPaneDivider.gripDotCount", 3 );
 		@Styleable protected int gripDotSize = FlatUIUtils.getUIInt( "SplitPaneDivider.gripDotSize", 3 );
@@ -246,20 +301,40 @@ public class FlatSplitPaneUI
 					// necessary to show/hide one-touch buttons on expand/collapse
 					doLayout();
 					break;
+
+				case FlatClientProperties.SPLIT_PANE_EXPANDABLE_SIDE:
+					revalidate();
+					break;
 			}
 		}
 
 		@Override
 		public void paint( Graphics g ) {
+			// paint hover or pressed background
+			Color hoverOrPressedColor = (isContinuousLayout() && dragger != null)
+				? pressedColor
+				: (isMouseOver() && dragger == null
+					? hoverColor
+					: null);
+			if( hoverOrPressedColor != null ) {
+				g.setColor( FlatUIUtils.deriveColor( hoverOrPressedColor, splitPane.getBackground() ) );
+				g.fillRect( 0, 0, getWidth(), getHeight() );
+			}
+
 			super.paint( g );
 
+			paintStyle( g, 0, 0, getWidth(), getHeight() );
+		}
+
+		/** @since 3.3 */
+		protected void paintStyle( Graphics g, int x, int y, int width, int height ) {
 			if( "plain".equals( style ) )
 				return;
 
 			Object[] oldRenderingHints = FlatUIUtils.setRenderingHints( g );
 
 			g.setColor( gripColor );
-			paintGrip( g, 0, 0, getWidth(), getHeight() );
+			paintGrip( g, x, y, width, height );
 
 			FlatUIUtils.resetRenderingHints( g, oldRenderingHints );
 		}
@@ -286,6 +361,29 @@ public class FlatSplitPaneUI
 				: location == (splitPane.getWidth() - getWidth() - insets.right);
 		}
 
+		@Override
+		protected void setMouseOver( boolean mouseOver ) {
+			super.setMouseOver( mouseOver );
+			repaintIfNecessary();
+		}
+
+		@Override
+		protected void prepareForDragging() {
+			super.prepareForDragging();
+			repaintIfNecessary();
+		}
+
+		@Override
+		protected void finishDraggingTo( int location ) {
+			super.finishDraggingTo( location );
+			repaintIfNecessary();
+		}
+
+		private void repaintIfNecessary() {
+			if( hoverColor != null || pressedColor != null )
+				repaint();
+		}
+
 		//---- class FlatOneTouchButton ---------------------------------------
 
 		protected class FlatOneTouchButton

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatStylingSupport.java

@@ -40,8 +40,8 @@ import javax.swing.UIManager;
 import javax.swing.border.Border;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.FlatLaf;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.StringUtils;
-import com.formdev.flatlaf.util.SystemInfo;
 
 /**
  * Support for styling components in CSS syntax.
@@ -324,22 +324,24 @@ public class FlatStylingSupport
 			return null;
 
 		Map<String, Object> oldValues = new HashMap<>();
+		outer:
 		for( Map.Entry<String, Object> e : style.entrySet() ) {
 			String key = e.getKey();
 			Object newValue = e.getValue();
 
 			// handle key prefix
-			if( key.startsWith( "[" ) ) {
-				if( (SystemInfo.isWindows && key.startsWith( "[win]" )) ||
-					(SystemInfo.isMacOS && key.startsWith( "[mac]" )) ||
-					(SystemInfo.isLinux && key.startsWith( "[linux]" )) ||
-					(key.startsWith( "[light]" ) && !FlatLaf.isLafDark()) ||
-					(key.startsWith( "[dark]" ) && FlatLaf.isLafDark()) )
-				{
+			while( key.startsWith( "[" ) ) {
+				int closeIndex = key.indexOf( ']' );
+				if( closeIndex < 0 )
+					continue outer;
+
+				String prefix = key.substring( 0, closeIndex + 1 );
+				String lightOrDarkPrefix = FlatLaf.getUIKeyLightOrDarkPrefix( FlatLaf.isLafDark() );
+				if( !lightOrDarkPrefix.equals( prefix ) && !FlatLaf.getUIKeyPlatformPrefixes().contains( prefix ) )
+					continue outer;
+
 				// prefix is known and enabled --> remove prefix
-					key = key.substring( key.indexOf( ']' ) + 1 );
-				} else
-					continue;
+				key = key.substring( closeIndex + 1 );
 			}
 
 			Object oldValue = applyProperty.apply( key, newValue );
@@ -709,7 +711,7 @@ public class FlatStylingSupport
 				case FlatClientProperties.STYLE_CLASS:
 					installStyle.run();
 					c.revalidate();
-					c.repaint();
+					HiDPIUtils.repaint( c );
 					break;
 			}
 		};

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTableCellBorder.java

@@ -65,8 +65,28 @@ public class FlatTableCellBorder
 		return super.getLineColor();
 	}
 
+	@Override
+	public int getArc() {
+		if( c != null ) {
+			Integer selectionArc = getStyleFromTableUI( c, ui -> ui.selectionArc );
+			if( selectionArc != null )
+				return selectionArc;
+		}
+		return super.getArc();
+	}
+
 	@Override
 	public void paintBorder( Component c, Graphics g, int x, int y, int width, int height ) {
+		if( c != null ) {
+			Insets selectionInsets = getStyleFromTableUI( c, ui -> ui.selectionInsets );
+			if( selectionInsets != null ) {
+				x += selectionInsets.left;
+				y += selectionInsets.top;
+				width -= selectionInsets.left + selectionInsets.right;
+				height -= selectionInsets.top + selectionInsets.bottom;
+			}
+		}
+
 		this.c = c;
 		super.paintBorder( c, g, x, y, width, height );
 		this.c = null;

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTableHeaderUI.java

@@ -18,6 +18,7 @@ package com.formdev.flatlaf.ui;
 
 import java.awt.Color;
 import java.awt.Component;
+import java.awt.Container;
 import java.awt.Cursor;
 import java.awt.Dimension;
 import java.awt.Graphics;
@@ -28,16 +29,15 @@ import java.awt.event.MouseEvent;
 import java.awt.geom.Rectangle2D;
 import java.beans.PropertyChangeListener;
 import java.util.Map;
+import javax.swing.CellRendererPane;
 import javax.swing.Icon;
 import javax.swing.JComponent;
 import javax.swing.JLabel;
 import javax.swing.JTable;
 import javax.swing.SwingConstants;
 import javax.swing.UIManager;
-import javax.swing.border.Border;
 import javax.swing.event.MouseInputListener;
 import javax.swing.plaf.ComponentUI;
-import javax.swing.plaf.UIResource;
 import javax.swing.plaf.basic.BasicTableHeaderUI;
 import javax.swing.table.JTableHeader;
 import javax.swing.table.TableCellRenderer;
@@ -45,6 +45,7 @@ import javax.swing.table.TableColumn;
 import javax.swing.table.TableColumnModel;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.UIScale;
 
@@ -114,6 +115,11 @@ public class FlatTableHeaderUI
 	public void installUI( JComponent c ) {
 		super.installUI( c );
 
+		// replace cell renderer pane
+		header.remove( rendererPane );
+		rendererPane = new FlatTableHeaderCellRendererPane();
+		header.add( rendererPane );
+
 		installStyle();
 	}
 
@@ -229,8 +235,8 @@ public class FlatTableHeaderUI
 
 	@Override
 	protected void rolloverColumnUpdated( int oldColumn, int newColumn ) {
-		header.repaint( header.getHeaderRect( oldColumn ) );
-		header.repaint( header.getHeaderRect( newColumn ) );
+		HiDPIUtils.repaint( header, header.getHeaderRect( oldColumn ) );
+		HiDPIUtils.repaint( header, header.getHeaderRect( newColumn ) );
 	}
 
 	@Override
@@ -265,16 +271,8 @@ public class FlatTableHeaderUI
 			}
 		}
 
-		// temporary use own default renderer
-		FlatTableCellHeaderRenderer tempRenderer = new FlatTableCellHeaderRenderer( header.getDefaultRenderer() );
-		header.setDefaultRenderer( tempRenderer );
-
 		// paint header
 		super.paint( g, c );
-
-		// restore default renderer
-		tempRenderer.reset();
-		header.setDefaultRenderer( tempRenderer.delegate );
 	}
 
 	private boolean isSystemDefaultRenderer( Object headerRenderer ) {
@@ -332,119 +330,129 @@ public class FlatTableHeaderUI
 		return false;
 	}
 
-	//---- class FlatTableCellHeaderRenderer ----------------------------------
+	//---- class FlatTableHeaderCellRendererPane ------------------------------
 
 	/**
-	 * A delegating header renderer that is only used to paint hover and pressed
-	 * background/foreground and to paint sort arrows at top, bottom or left position.
+	 * Cell renderer pane that is used to paint hover and pressed background/foreground
+	 * and to paint sort arrows at top, bottom or left position.
 	 */
-	private class FlatTableCellHeaderRenderer
-		implements TableCellRenderer, Border, UIResource
+	private class FlatTableHeaderCellRendererPane
+		extends CellRendererPane
 	{
-		private final TableCellRenderer delegate;
+		private final Icon ascendingSortIcon;
+		private final Icon descendingSortIcon;
 
-		private JLabel l;
-		private Color oldBackground;
-		private Color oldForeground;
-		private Boolean oldOpaque;
-		private int oldHorizontalTextPosition = -1;
-		private Border origBorder;
-		private Icon sortIcon;
-
-		FlatTableCellHeaderRenderer( TableCellRenderer delegate ) {
-			this.delegate = delegate;
+		public FlatTableHeaderCellRendererPane() {
+			ascendingSortIcon = UIManager.getIcon( "Table.ascendingSortIcon" );
+			descendingSortIcon = UIManager.getIcon( "Table.descendingSortIcon" );
 		}
 
 		@Override
-		public Component getTableCellRendererComponent( JTable table, Object value, boolean isSelected,
-			boolean hasFocus, int row, int column )
-		{
-			Component c = delegate.getTableCellRendererComponent( table, value, isSelected, hasFocus, row, column );
-			if( !(c instanceof JLabel) )
-				return c;
+		public void paintComponent( Graphics g, Component c, Container p, int x, int y, int w, int h, boolean shouldValidate ) {
+			if( !(c instanceof JLabel) ) {
+				super.paintComponent( g, c, p, x, y, w, h, shouldValidate );
+				return;
+			}
 
-			l = (JLabel) c;
+			JLabel l = (JLabel) c;
+			Color oldBackground = null;
+			Color oldForeground = null;
+			boolean oldOpaque = false;
+			Icon oldIcon = null;
+			int oldHorizontalTextPosition = -1;
 
 			// hover and pressed background/foreground
 			TableColumn draggedColumn = header.getDraggedColumn();
 			Color background = null;
 			Color foreground = null;
-			if( draggedColumn != null && header.getTable().convertColumnIndexToView( draggedColumn.getModelIndex() ) == column ) {
+			if( draggedColumn != null &&
+				header.getTable().convertColumnIndexToView( draggedColumn.getModelIndex() )
+					== getColumn( x - header.getDraggedDistance(), w ) )
+			{
 				background = pressedBackground;
 				foreground = pressedForeground;
-			} else if( getRolloverColumn() == column ) {
+			} else if( getRolloverColumn() >= 0 && getRolloverColumn() == getColumn( x, w ) ) {
 				background = hoverBackground;
 				foreground = hoverForeground;
 			}
 			if( background != null ) {
-				if( oldBackground == null )
 				oldBackground = l.getBackground();
-				if( oldOpaque == null )
 				oldOpaque = l.isOpaque();
 				l.setBackground( FlatUIUtils.deriveColor( background, header.getBackground() ) );
 				l.setOpaque( true );
 			}
 			if( foreground != null ) {
-				if( oldForeground == null )
 				oldForeground = l.getForeground();
 				l.setForeground( FlatUIUtils.deriveColor( foreground, header.getForeground() ) );
 			}
 
-			// sort icon
+			// sort icon position
+			Icon icon = l.getIcon();
+			boolean isSortIcon = (icon != null && (icon == ascendingSortIcon || icon == descendingSortIcon));
+			if( isSortIcon ) {
 				if( sortIconPosition == SwingConstants.LEFT ) {
 					// left
-				if( oldHorizontalTextPosition < 0 )
 					oldHorizontalTextPosition = l.getHorizontalTextPosition();
 					l.setHorizontalTextPosition( SwingConstants.RIGHT );
 				} else if( sortIconPosition == SwingConstants.TOP || sortIconPosition == SwingConstants.BOTTOM ) {
 					// top or bottom
-				sortIcon = l.getIcon();
-				origBorder = l.getBorder();
+					oldIcon = icon;
 					l.setIcon( null );
-				l.setBorder( this );
+				}
 			}
 
-			return l;
+			// paint renderer component
+			super.paintComponent( g, c, p, x, y, w, h, shouldValidate );
+
+			// paint top or bottom sort icon
+			if( isSortIcon && (sortIconPosition == SwingConstants.TOP || sortIconPosition == SwingConstants.BOTTOM) ) {
+				int xi = x + ((w - icon.getIconWidth()) / 2);
+				int yi = (sortIconPosition == SwingConstants.TOP)
+					? y + UIScale.scale( 1 )
+					: y + height - icon.getIconHeight()
+						- 1 // for gap
+						- (int) (1 * UIScale.getUserScaleFactor()); // for bottom border
+				icon.paintIcon( c, g, xi, yi );
 			}
 
-		void reset() {
-			if( l == null )
-				return;
-
-			if( oldBackground != null )
+			// restore modified renderer component properties
+			if( background != null ) {
 				l.setBackground( oldBackground );
-			if( oldForeground != null )
-				l.setForeground( oldForeground );
-			if( oldOpaque != null )
 				l.setOpaque( oldOpaque );
+			}
+			if( foreground != null )
+				l.setForeground( oldForeground );
+			if( oldIcon != null )
+				l.setIcon( oldIcon );
 			if( oldHorizontalTextPosition >= 0 )
 				l.setHorizontalTextPosition( oldHorizontalTextPosition );
 		}
 
-		@Override
-		public void paintBorder( Component c, Graphics g, int x, int y, int width, int height ) {
-			if( origBorder != null )
-				origBorder.paintBorder( c, g, x, y, width, height );
+		/**
+		 * Get column index for given coordinates.
+		 */
+		private int getColumn( int x, int width ) {
+			TableColumnModel columnModel = header.getColumnModel();
+			int columnCount = columnModel.getColumnCount();
+			boolean ltr = header.getComponentOrientation().isLeftToRight();
+			int cx = ltr ? 0 : getWidthInRightToLef();
 
-			if( sortIcon != null ) {
-				int xi = x + ((width - sortIcon.getIconWidth()) / 2);
-				int yi = (sortIconPosition == SwingConstants.TOP)
-					? y + UIScale.scale( 1 )
-					: y + height - sortIcon.getIconHeight()
-						- 1 // for gap
-						- (int) (1 * UIScale.getUserScaleFactor()); // for bottom border
-				sortIcon.paintIcon( c, g, xi, yi );
+			for( int i = 0; i < columnCount; i++ ) {
+				int cw = columnModel.getColumn( i ).getWidth();
+				if( x == cx - (ltr ? 0 : cw) && width == cw )
+					return i;
+
+				cx += ltr ? cw : -cw;
 			}
+			return -1;
 		}
 
-		@Override
-		public Insets getBorderInsets( Component c ) {
-			return (origBorder != null) ? origBorder.getBorderInsets( c ) : new Insets( 0, 0, 0, 0 );
-		}
-
-		@Override
-		public boolean isBorderOpaque() {
-			return (origBorder != null) ? origBorder.isBorderOpaque() : false;
+		// similar to JTableHeader.getWidthInRightToLeft()
+		private int getWidthInRightToLef() {
+			JTable table = header.getTable();
+			return (table != null && table.getAutoResizeMode() != JTable.AUTO_RESIZE_OFF)
+				? table.getWidth()
+				: header.getWidth();
 		}
 	}
 

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTableUI.java

@@ -17,30 +17,57 @@
 package com.formdev.flatlaf.ui;
 
 import java.awt.Color;
+import java.awt.Component;
 import java.awt.Container;
 import java.awt.Dimension;
 import java.awt.EventQueue;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.Insets;
+import java.awt.Point;
+import java.awt.Rectangle;
+import java.awt.Shape;
+import java.awt.event.ActionEvent;
+import java.awt.event.ComponentAdapter;
+import java.awt.event.ComponentEvent;
+import java.awt.event.ComponentListener;
 import java.awt.event.FocusEvent;
 import java.awt.event.FocusListener;
 import java.awt.geom.Rectangle2D;
+import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
 import java.util.Map;
+import javax.swing.Action;
+import javax.swing.ActionMap;
+import javax.swing.Icon;
 import javax.swing.JComponent;
 import javax.swing.JScrollPane;
+import javax.swing.JTable;
+import javax.swing.JTextField;
 import javax.swing.JViewport;
+import javax.swing.ListSelectionModel;
 import javax.swing.LookAndFeel;
+import javax.swing.SwingConstants;
 import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
+import javax.swing.event.ChangeEvent;
+import javax.swing.event.ListSelectionEvent;
+import javax.swing.event.ListSelectionListener;
+import javax.swing.event.TableColumnModelEvent;
+import javax.swing.event.TableColumnModelListener;
 import javax.swing.plaf.ComponentUI;
+import javax.swing.plaf.UIResource;
 import javax.swing.plaf.basic.BasicTableUI;
+import javax.swing.table.DefaultTableCellRenderer;
 import javax.swing.table.JTableHeader;
+import javax.swing.table.TableCellRenderer;
+import javax.swing.table.TableColumnModel;
 import com.formdev.flatlaf.FlatClientProperties;
+import com.formdev.flatlaf.icons.FlatCheckBoxIcon;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
 import com.formdev.flatlaf.util.Graphics2DProxy;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.SystemInfo;
 import com.formdev.flatlaf.util.UIScale;
@@ -80,7 +107,10 @@ import com.formdev.flatlaf.util.UIScale;
  * @uiDefault Table.intercellSpacing					Dimension
  * @uiDefault Table.selectionInactiveBackground			Color
  * @uiDefault Table.selectionInactiveForeground			Color
+ * @uiDefault Table.selectionInsets						Insets
+ * @uiDefault Table.selectionArc						int
  * @uiDefault Table.paintOutsideAlternateRows			boolean
+ * @uiDefault Table.editorSelectAllOnStartEditing		boolean
  *
  * <!-- FlatTableCellBorder -->
  *
@@ -107,6 +137,8 @@ public class FlatTableUI
 	@Styleable protected Color selectionForeground;
 	@Styleable protected Color selectionInactiveBackground;
 	@Styleable protected Color selectionInactiveForeground;
+	/** @since 3.5 */ @Styleable protected Insets selectionInsets;
+	/** @since 3.5 */ @Styleable protected int selectionArc;
 
 	// for FlatTableCellBorder
 	/** @since 2 */ @Styleable protected Insets cellMargins;
@@ -116,8 +148,12 @@ public class FlatTableUI
 	private boolean oldShowHorizontalLines;
 	private boolean oldShowVerticalLines;
 	private Dimension oldIntercellSpacing;
+	private TableCellRenderer oldBooleanRenderer;
 
 	private PropertyChangeListener propertyChangeListener;
+	private ComponentListener outsideAlternateRowsListener;
+	private ListSelectionListener rowSelectionListener;
+	private TableColumnModelListener columnSelectionListener;
 	private Map<String, Object> oldStyleValues;
 
 	public static ComponentUI createUI( JComponent c ) {
@@ -144,6 +180,8 @@ public class FlatTableUI
 		selectionForeground = UIManager.getColor( "Table.selectionForeground" );
 		selectionInactiveBackground = UIManager.getColor( "Table.selectionInactiveBackground" );
 		selectionInactiveForeground = UIManager.getColor( "Table.selectionInactiveForeground" );
+		selectionInsets = UIManager.getInsets( "Table.selectionInsets" );
+		selectionArc = UIManager.getInt( "Table.selectionArc" );
 
 		toggleSelectionColors();
 
@@ -151,19 +189,35 @@ public class FlatTableUI
 		if( rowHeight > 0 )
 			LookAndFeel.installProperty( table, "rowHeight", UIScale.scale( rowHeight ) );
 
-		if( !showHorizontalLines ) {
+		FlatTablePropertyWatcher watcher = FlatTablePropertyWatcher.get( table );
+		if( watcher != null )
+			watcher.enabled = false;
+
+		if( !showHorizontalLines && (watcher == null || !watcher.showHorizontalLinesChanged) ) {
 			oldShowHorizontalLines = table.getShowHorizontalLines();
 			table.setShowHorizontalLines( false );
 		}
-		if( !showVerticalLines ) {
+		if( !showVerticalLines && (watcher == null || !watcher.showVerticalLinesChanged) ) {
 			oldShowVerticalLines = table.getShowVerticalLines();
 			table.setShowVerticalLines( false );
 		}
 
-		if( intercellSpacing != null ) {
+		if( intercellSpacing != null && (watcher == null || !watcher.intercellSpacingChanged) ) {
 			oldIntercellSpacing = table.getIntercellSpacing();
 			table.setIntercellSpacing( intercellSpacing );
 		}
+
+		if( watcher != null )
+			watcher.enabled = true;
+		else
+			table.addPropertyChangeListener( new FlatTablePropertyWatcher() );
+
+		// install boolean renderer
+		oldBooleanRenderer = table.getDefaultRenderer( Boolean.class );
+		if( oldBooleanRenderer instanceof UIResource )
+			table.setDefaultRenderer( Boolean.class, new FlatBooleanRenderer() );
+		else
+			oldBooleanRenderer = null;
 	}
 
 	@Override
@@ -177,15 +231,36 @@ public class FlatTableUI
 
 		oldStyleValues = null;
 
+		FlatTablePropertyWatcher watcher = FlatTablePropertyWatcher.get( table );
+		if( watcher != null )
+			watcher.enabled = false;
+
 		// restore old show horizontal/vertical lines (if not modified)
-		if( !showHorizontalLines && oldShowHorizontalLines && !table.getShowHorizontalLines() )
+		if( !showHorizontalLines && oldShowHorizontalLines && !table.getShowHorizontalLines() &&
+			(watcher == null || !watcher.showHorizontalLinesChanged) )
 		  table.setShowHorizontalLines( true );
-		if( !showVerticalLines && oldShowVerticalLines && !table.getShowVerticalLines() )
+		if( !showVerticalLines && oldShowVerticalLines && !table.getShowVerticalLines() &&
+			(watcher == null || !watcher.showVerticalLinesChanged) )
 		  table.setShowVerticalLines( true );
 
 		// restore old intercell spacing (if not modified)
-		if( intercellSpacing != null && table.getIntercellSpacing().equals( intercellSpacing ) )
+		if( intercellSpacing != null && table.getIntercellSpacing().equals( intercellSpacing ) &&
+			(watcher == null || !watcher.intercellSpacingChanged) )
 		  table.setIntercellSpacing( oldIntercellSpacing );
+
+		if( watcher != null )
+			watcher.enabled = true;
+
+		// uninstall boolean renderer
+		if( table.getDefaultRenderer( Boolean.class ) instanceof FlatBooleanRenderer ) {
+			if( oldBooleanRenderer instanceof Component ) {
+				// because the old renderer component was not attached to any component hierarchy,
+				// its UI was not yet updated, and it is necessary to do it here
+				SwingUtilities.updateComponentTreeUI( (Component) oldBooleanRenderer );
+			}
+			table.setDefaultRenderer( Boolean.class, oldBooleanRenderer );
+		}
+		oldBooleanRenderer = null;
 	}
 
 	@Override
@@ -194,6 +269,28 @@ public class FlatTableUI
 
 		propertyChangeListener = e -> {
 			switch( e.getPropertyName() ) {
+				case "selectionModel":
+					if( rowSelectionListener != null ) {
+						Object oldModel = e.getOldValue();
+						Object newModel = e.getNewValue();
+						if( oldModel != null )
+							((ListSelectionModel)oldModel).removeListSelectionListener( rowSelectionListener );
+						if( newModel != null )
+							((ListSelectionModel)newModel).addListSelectionListener( rowSelectionListener );
+					}
+					break;
+
+				case "columnModel":
+					if( columnSelectionListener != null ) {
+						Object oldModel = e.getOldValue();
+						Object newModel = e.getNewValue();
+						if( oldModel != null )
+							((TableColumnModel)oldModel).removeColumnModelListener( columnSelectionListener );
+						if( newModel != null )
+							((TableColumnModel)newModel).addColumnModelListener( columnSelectionListener );
+					}
+					break;
+
 				case FlatClientProperties.COMPONENT_FOCUS_OWNER:
 					toggleSelectionColors();
 					break;
@@ -202,11 +299,14 @@ public class FlatTableUI
 				case FlatClientProperties.STYLE_CLASS:
 					installStyle();
 					table.revalidate();
-					table.repaint();
+					HiDPIUtils.repaint( table );
 					break;
 			}
 		};
 		table.addPropertyChangeListener( propertyChangeListener );
+
+		if( selectionArc > 0 )
+			installRepaintRoundedSelectionListeners();
 	}
 
 	@Override
@@ -215,6 +315,19 @@ public class FlatTableUI
 
 		table.removePropertyChangeListener( propertyChangeListener );
 		propertyChangeListener = null;
+
+		if( outsideAlternateRowsListener != null ) {
+			table.removeComponentListener( outsideAlternateRowsListener );
+			outsideAlternateRowsListener = null;
+		}
+		if( rowSelectionListener != null ) {
+			table.getSelectionModel().removeListSelectionListener( rowSelectionListener );
+			rowSelectionListener = null;
+		}
+		if( columnSelectionListener != null ) {
+			table.getColumnModel().removeColumnModelListener( columnSelectionListener );
+			columnSelectionListener = null;
+		}
 	}
 
 	@Override
@@ -238,6 +351,18 @@ public class FlatTableUI
 		};
 	}
 
+	@Override
+	protected void installKeyboardActions() {
+		super.installKeyboardActions();
+
+		if( UIManager.getBoolean( "Table.editorSelectAllOnStartEditing" ) ) {
+			// get shared action map, used for all tables
+			ActionMap map = SwingUtilities.getUIActionMap( table );
+			if( map != null )
+				StartEditingAction.install( map, "startEditing" );
+		}
+	}
+
 	/** @since 2 */
 	protected void installStyle() {
 		try {
@@ -279,6 +404,8 @@ public class FlatTableUI
 	protected Object applyStyleProperty( String key, Object value ) {
 		if( "rowHeight".equals( key ) && value instanceof Integer )
 			value = UIScale.scale( (Integer) value );
+		else if( "selectionArc".equals( key ) && value instanceof Integer && (Integer) value > 0 )
+			installRepaintRoundedSelectionListeners();
 
 		return FlatStylingSupport.applyToAnnotatedObjectOrComponent( this, table, key, value );
 	}
@@ -341,6 +468,7 @@ public class FlatTableUI
 
 			double systemScaleFactor = UIScale.getSystemScaleFactor( (Graphics2D) g );
 			double lineThickness = (1. / systemScaleFactor) * (int) systemScaleFactor;
+			double lineOffset = (1. - lineThickness) + 0.05; // adding 0.05 to fix line location in some cases
 
 			// Java 8 uses drawLine() to paint grid lines
 			// Java 9+ uses fillRect() to paint grid lines (except for dragged column)
@@ -383,11 +511,11 @@ public class FlatTableUI
 					// reduce line thickness to avoid unstable painted line thickness
 					if( lineThickness != 1 ) {
 						if( horizontalLines && height == 1 && wasInvokedFromPaintGrid() ) {
-							super.fill( new Rectangle2D.Double( x, y, width, lineThickness ) );
+							super.fill( new Rectangle2D.Double( x, y + lineOffset, width, lineThickness ) );
 							return;
 						}
 						if( verticalLines && width == 1 && y == 0 && wasInvokedFromPaintGrid() ) {
-							super.fill( new Rectangle2D.Double( x, y, lineThickness, height ) );
+							super.fill( new Rectangle2D.Double( x + lineOffset, y, lineThickness, height ) );
 							return;
 						}
 					}
@@ -405,6 +533,10 @@ public class FlatTableUI
 			};
 		}
 
+		// rounded selection or selection insets
+		if( selectionArc > 0 || (selectionInsets != null && !FlatUIUtils.isInsetsEmpty( selectionInsets )) )
+			g = new RoundedSelectionGraphics( g, UIManager.getColor( "Table.alternateRowColor" ) );
+
 		super.paint( g, c );
 	}
 
@@ -450,8 +582,6 @@ public class FlatTableUI
 		boolean paintOutside = UIManager.getBoolean( "Table.paintOutsideAlternateRows" );
 		Color alternateColor;
 		if( paintOutside && (alternateColor = UIManager.getColor( "Table.alternateRowColor" )) != null ) {
-			g.setColor( alternateColor );
-
 			int rowCount = table.getRowCount();
 
 			// paint alternating empty rows below the table
@@ -460,11 +590,451 @@ public class FlatTableUI
 				int tableWidth = table.getWidth();
 				int rowHeight = table.getRowHeight();
 
+				g.setColor( alternateColor );
+
+				int x = viewport.getComponentOrientation().isLeftToRight() ? 0 : viewportWidth - tableWidth;
 				for( int y = tableHeight, row = rowCount; y < viewportHeight; y += rowHeight, row++ ) {
 					if( row % 2 != 0 )
-						g.fillRect( 0, y, tableWidth, rowHeight );
+						paintAlternateRowBackground( g, -1, -1, x, y, tableWidth, rowHeight );
+				}
+
+				// add listener on demand
+				if( outsideAlternateRowsListener == null && table.getAutoResizeMode() == JTable.AUTO_RESIZE_OFF ) {
+					outsideAlternateRowsListener = new FlatOutsideAlternateRowsListener();
+					table.addComponentListener( outsideAlternateRowsListener );
 				}
 			}
 		}
 	}
+
+	/**
+	 * Paints (rounded) alternate row background.
+	 * Supports {@link #selectionArc} and {@link #selectionInsets}.
+	 * <p>
+	 * <b>Note:</b> This method is only invoked if either selection arc
+	 *              is greater than zero or if selection insets are not empty.
+	 *
+	 * @since 3.5
+	 */
+	protected void paintAlternateRowBackground( Graphics g, int row, int column, int x, int y, int width, int height ) {
+		Insets insets = (selectionInsets != null) ? (Insets) selectionInsets.clone() : null;
+		float arcTopLeft, arcTopRight, arcBottomLeft, arcBottomRight;
+		arcTopLeft = arcTopRight = arcBottomLeft = arcBottomRight = UIScale.scale( selectionArc / 2f );
+
+		if( column >= 0 ) {
+			// selection insets
+
+			// selection arc
+			if( column > 0 ) {
+				if( insets != null )
+					insets.left = 0;
+
+				if( table.getComponentOrientation().isLeftToRight() )
+					arcTopLeft = arcBottomLeft = 0;
+				else
+					arcTopRight = arcBottomRight = 0;
+			}
+			if( column < table.getColumnCount() - 1 ) {
+				if( insets != null )
+					insets.right = 0;
+
+				if( table.getComponentOrientation().isLeftToRight() )
+					arcTopRight = arcBottomRight = 0;
+				else
+					arcTopLeft = arcBottomLeft = 0;
+			}
+		}
+
+		FlatUIUtils.paintSelection( (Graphics2D) g, x, y, width, height,
+			UIScale.scale( insets ), arcTopLeft, arcTopRight, arcBottomLeft, arcBottomRight, 0 );
+	}
+
+	/**
+	 * Paints (rounded) cell selection.
+	 * Supports {@link #selectionArc} and {@link #selectionInsets}.
+	 * <p>
+	 * <b>Note:</b> This method is only invoked if either selection arc
+	 *              is greater than zero or if selection insets are not empty.
+	 *
+	 * @since 3.5
+	 */
+	protected void paintCellSelection( Graphics g, int row, int column, int x, int y, int width, int height ) {
+		boolean rowSelAllowed = table.getRowSelectionAllowed();
+		boolean colSelAllowed = table.getColumnSelectionAllowed();
+		boolean rowSelOnly = rowSelAllowed && !colSelAllowed;
+		boolean colSelOnly = colSelAllowed && !rowSelAllowed;
+		boolean cellOnlySel = rowSelAllowed && colSelAllowed;
+
+		// get selection state of surrounding cells
+		boolean leftSelected    = (column > 0 && (rowSelOnly || table.isCellSelected( row, column - 1 )));
+		boolean topSelected     = (row    > 0 && (colSelOnly || table.isCellSelected( row - 1, column )));
+		boolean rightSelected   = (column < table.getColumnCount() - 1 && (rowSelOnly || table.isCellSelected( row, column + 1 )));
+		boolean bottomSelected  = (row    < table.getRowCount() - 1    && (colSelOnly || table.isCellSelected( row + 1, column )));
+		if( !table.getComponentOrientation().isLeftToRight() ) {
+			boolean temp = leftSelected;
+			leftSelected = rightSelected;
+			rightSelected = temp;
+		}
+
+		// selection insets
+		// (insets are applied to whole row if row-only selection is used,
+		//  or to whole column if column-only selection is used,
+		//  or to cell if cell selection is used)
+		Insets insets = (selectionInsets != null) ? (Insets) selectionInsets.clone() : null;
+		if( insets != null ) {
+			if( rowSelOnly && leftSelected )
+				insets.left = 0;
+			if( rowSelOnly && rightSelected )
+				insets.right = 0;
+			if( colSelOnly && topSelected )
+				insets.top = 0;
+			if( colSelOnly && bottomSelected )
+				insets.bottom = 0;
+		}
+
+		// selection arc
+		float arcTopLeft, arcTopRight, arcBottomLeft, arcBottomRight;
+		arcTopLeft = arcTopRight = arcBottomLeft = arcBottomRight = UIScale.scale( selectionArc / 2f );
+		if( selectionArc > 0 ) {
+			// note that intercellSpacing is not considered as a gap because
+			// grid lines are usually painted to intercell space
+			boolean hasRowGap = (rowSelOnly || cellOnlySel) && insets != null && (insets.top != 0 || insets.bottom != 0);
+			boolean hasColGap = (colSelOnly || cellOnlySel) && insets != null && (insets.left != 0 || insets.right != 0);
+
+			if( leftSelected && !hasColGap )
+				arcTopLeft = arcBottomLeft = 0;
+			if( rightSelected && !hasColGap )
+				arcTopRight = arcBottomRight = 0;
+			if( topSelected && !hasRowGap )
+				arcTopLeft = arcTopRight = 0;
+			if( bottomSelected && !hasRowGap )
+				arcBottomLeft = arcBottomRight = 0;
+		}
+
+		FlatUIUtils.paintSelection( (Graphics2D) g, x, y, width, height,
+			UIScale.scale( insets ), arcTopLeft, arcTopRight, arcBottomLeft, arcBottomRight, 0 );
+	}
+
+	/**
+	 * Paints a cell selection at the given coordinates.
+	 * The selection color must be set on the graphics context.
+	 * <p>
+	 * This method is intended for use in custom cell renderers to support
+	 * {@link #selectionArc} and {@link #selectionInsets}.
+	 *
+	 * @since 3.5
+	 */
+	public static void paintCellSelection( JTable table, Graphics g, int row, int column, int x, int y, int width, int height ) {
+		if( !(table.getUI() instanceof FlatTableUI) )
+			return;
+
+		FlatTableUI ui = (FlatTableUI) table.getUI();
+		ui.paintCellSelection( g, row, column, x, y, width, height );
+	}
+
+	private void installRepaintRoundedSelectionListeners() {
+		if( rowSelectionListener == null ) {
+			rowSelectionListener = this::repaintRoundedRowSelection;
+			table.getSelectionModel().addListSelectionListener( rowSelectionListener );
+		}
+
+		if( columnSelectionListener == null ) {
+			columnSelectionListener = new TableColumnModelListener() {
+				@Override
+				public void columnSelectionChanged( ListSelectionEvent e ) {
+					repaintRoundedColumnSelection( e );
+				}
+				@Override public void columnRemoved( TableColumnModelEvent e ) {}
+				@Override public void columnMoved( TableColumnModelEvent e ) {}
+				@Override public void columnMarginChanged( ChangeEvent e ) {}
+				@Override public void columnAdded( TableColumnModelEvent e ) {}
+			};
+			table.getColumnModel().addColumnModelListener( columnSelectionListener );
+		}
+	}
+
+	private void repaintRoundedRowSelection( ListSelectionEvent e ) {
+		if( selectionArc <= 0 || !table.getRowSelectionAllowed() )
+			return;
+
+		int rowCount = table.getRowCount();
+		int columnCount = table.getColumnCount();
+		if( rowCount <= 0 || columnCount <= 0 )
+			return;
+
+		// repaint including rows before and after changed selection
+		int firstRow = Math.max( 0, Math.min( e.getFirstIndex() - 1, rowCount - 1 ) );
+		int lastRow = Math.max( 0, Math.min( e.getLastIndex() + 1, rowCount - 1 ) );
+		Rectangle firstRect = table.getCellRect( firstRow, 0, false );
+		Rectangle lastRect = table.getCellRect( lastRow, columnCount - 1, false );
+		table.repaint( firstRect.union( lastRect ) );
+	}
+
+	private void repaintRoundedColumnSelection( ListSelectionEvent e ) {
+		if( selectionArc <= 0 || !table.getColumnSelectionAllowed() )
+			return;
+
+		int rowCount = table.getRowCount();
+		int columnCount = table.getColumnCount();
+		if( rowCount <= 0 || columnCount <= 0 )
+			return;
+
+		// limit to selected rows for cell selection
+		int firstRow = 0;
+		int lastRow = rowCount - 1;
+		if( table.getRowSelectionAllowed() ) {
+			firstRow = table.getSelectionModel().getMinSelectionIndex();
+			lastRow = table.getSelectionModel().getMaxSelectionIndex();
+		}
+
+		// repaint including columns before and after changed selection
+		int firstColumn = Math.max( 0, Math.min( e.getFirstIndex() - 1, columnCount - 1 ) );
+		int lastColumn = Math.max( 0, Math.min( e.getLastIndex() + 1, columnCount - 1 ) );
+		Rectangle firstRect = table.getCellRect( firstRow, firstColumn, false );
+		Rectangle lastRect = table.getCellRect( lastRow, lastColumn, false );
+		table.repaint( firstRect.union( lastRect ) );
+	}
+
+	//---- class RoundedSelectionGraphics -------------------------------------
+
+	/**
+	 * Because selection painting is done in the cell renderer, it would be
+	 * necessary to require a FlatLaf specific renderer to implement rounded selection.
+	 * Using a LaF specific renderer was avoided because often a custom renderer is
+	 * already used in applications. Then either the rounded selection is not used,
+	 * or the application has to be changed to extend a FlatLaf renderer.
+	 * <p>
+	 * To solve this, a graphics proxy is used that paints rounded selection
+	 * if row/column/cell is selected and the renderer wants to fill the background.
+	 */
+	private class RoundedSelectionGraphics
+		extends Graphics2DProxy
+	{
+		private final Color alternateRowColor;
+
+		// used to avoid endless loop in case that paintCellSelection() invokes
+		// g.fillRect() with full bounds (selectionInsets is 0,0,0,0)
+		private boolean inPaintSelection;
+
+		RoundedSelectionGraphics( Graphics delegate, Color alternateRowColor ) {
+			super( (Graphics2D) delegate );
+			this.alternateRowColor = alternateRowColor;
+		}
+
+		@Override
+		public Graphics create() {
+			return new RoundedSelectionGraphics( super.create(), alternateRowColor );
+		}
+
+		@Override
+		public Graphics create( int x, int y, int width, int height ) {
+			return new RoundedSelectionGraphics( super.create( x, y, width, height ), alternateRowColor );
+		}
+
+		@Override
+		public void fillRect( int x, int y, int width, int height ) {
+			if( fillCellSelection( x, y, width, height ) )
+				return;
+
+			super.fillRect( x, y, width, height );
+		}
+
+		@Override
+		public void fill( Shape shape ) {
+			if( shape instanceof Rectangle2D ) {
+				Rectangle2D r = (Rectangle2D) shape;
+				double x = r.getX();
+				double y = r.getY();
+				double width = r.getWidth();
+				double height = r.getHeight();
+				if( x == (int) x && y == (int) y && width == (int) width && height == (int) height ) {
+					if( fillCellSelection( (int) x, (int) y, (int) width, (int) height ) )
+						return;
+				}
+			}
+
+			super.fill( shape );
+		}
+
+		private boolean fillCellSelection( int x, int y, int width, int height ) {
+			if( inPaintSelection )
+				return false;
+
+			Color color;
+			Component rendererComponent;
+			if( x == 0 && y == 0 &&
+				((color = getColor()) == table.getSelectionBackground() ||
+				 (alternateRowColor != null && color == alternateRowColor)) &&
+				(rendererComponent = findActiveRendererComponent()) != null &&
+				width == rendererComponent.getWidth() &&
+				height == rendererComponent.getHeight() )
+			{
+				Point location = rendererComponent.getLocation();
+				int row = table.rowAtPoint( location );
+				int column = table.columnAtPoint( location );
+				if( row >= 0 && column >= 0 ) {
+					inPaintSelection = true;
+					if( color == table.getSelectionBackground() )
+						paintCellSelection( this, row, column, x, y, width, height );
+					else
+						paintAlternateRowBackground( this, row, column, x, y, width, height );
+					inPaintSelection = false;
+
+					return true;
+				}
+			}
+			return false;
+		}
+
+		/**
+		 * A CellRendererPane may contain multiple components, if multiple renderers
+		 * are used. Inactive renderer components have size {@code 0x0}.
+		 */
+		private Component findActiveRendererComponent() {
+			int count = rendererPane.getComponentCount();
+			for( int i = 0; i < count; i++ ) {
+				Component c = rendererPane.getComponent( i );
+				if( c.getWidth() > 0 && c.getHeight() > 0 )
+					return c;
+			}
+			return null;
+		}
+	}
+
+	//---- class OutsideAlternateRowsListener ---------------------------------
+
+	/**
+	 * Used if table auto-resize-mode is off to repaint outside alternate rows
+	 * when table width changed (column resized) or component orientation changed.
+	 */
+	private class FlatOutsideAlternateRowsListener
+		extends ComponentAdapter
+	{
+		@Override
+		public void componentHidden( ComponentEvent e ) {
+			Container viewport = SwingUtilities.getUnwrappedParent( table );
+			if( viewport instanceof JViewport )
+				HiDPIUtils.repaint( viewport );
+		}
+
+		@Override
+		public void componentMoved( ComponentEvent e ) {
+			repaintAreaBelowTable();
+		}
+
+		@Override
+		public void componentResized( ComponentEvent e ) {
+			repaintAreaBelowTable();
+		}
+
+		private void repaintAreaBelowTable() {
+			Container viewport = SwingUtilities.getUnwrappedParent( table );
+			if( viewport instanceof JViewport ) {
+				int viewportHeight = viewport.getHeight();
+				int tableHeight = table.getHeight();
+				if( tableHeight < viewportHeight )
+					HiDPIUtils.repaint( viewport, 0, tableHeight, viewport.getWidth(), viewportHeight - tableHeight );
+			}
+		}
+	}
+
+	//---- class FlatTablePropertyWatcher -------------------------------------
+
+	/**
+	 * Listener that watches for change of some table properties from application code.
+	 * This information is used in {@link FlatTableUI#installDefaults()} and
+	 * {@link FlatTableUI#uninstallDefaults()} to decide whether FlatLaf modifies those properties.
+	 * If they are modified in application code, FlatLaf no longer changes them.
+	 *
+	 * The listener is added once for each table, but never removed.
+	 * So switching Laf/theme reuses existing listener.
+	 */
+	private static class FlatTablePropertyWatcher
+		implements PropertyChangeListener
+	{
+		boolean enabled = true;
+		boolean showHorizontalLinesChanged;
+		boolean showVerticalLinesChanged;
+		boolean intercellSpacingChanged;
+
+		static FlatTablePropertyWatcher get( JTable table ) {
+			for( PropertyChangeListener l : table.getPropertyChangeListeners() ) {
+				if( l instanceof FlatTablePropertyWatcher )
+					return (FlatTablePropertyWatcher) l;
+			}
+			return null;
+		}
+
+		//---- interface PropertyChangeListener ----
+
+		@Override
+		public void propertyChange( PropertyChangeEvent e ) {
+			if( !enabled )
+				return;
+
+			switch( e.getPropertyName() ) {
+				case "showHorizontalLines":	showHorizontalLinesChanged = true; break;
+				case "showVerticalLines":	showVerticalLinesChanged = true; break;
+				case "rowMargin":			intercellSpacingChanged = true; break;
+			}
+		}
+	}
+
+	//---- class FlatBooleanRenderer ------------------------------------------
+
+	private static class FlatBooleanRenderer
+		extends DefaultTableCellRenderer
+		implements UIResource
+	{
+		private boolean selected;
+
+		FlatBooleanRenderer() {
+			setHorizontalAlignment( SwingConstants.CENTER );
+			Icon icon = new FlatCheckBoxIcon() {
+				@Override
+				protected boolean isSelected( Component c ) {
+					return selected;
+				}
+			};
+			setIcon( icon );
+			setDisabledIcon( icon );
+		}
+
+		@Override
+		protected void setValue( Object value ) {
+			selected = (value != null && (Boolean) value);
+		}
+	}
+
+	//---- class StartEditingAction -------------------------------------------
+
+	private static class StartEditingAction
+		extends FlatUIAction
+	{
+		static void install( ActionMap map, String key ) {
+			Action oldAction = map.get( key );
+			if( oldAction == null || oldAction instanceof StartEditingAction )
+				return; // not found or already installed
+
+			map.put( key, new StartEditingAction( oldAction ) );
+		}
+
+		private StartEditingAction( Action delegate ) {
+			super( delegate );
+		}
+
+		@Override
+		public void actionPerformed( ActionEvent e ) {
+			JTable table = (JTable) e.getSource();
+
+			Component oldEditorComp = table.getEditorComponent();
+
+			delegate.actionPerformed( e );
+
+			// select all text in editor if editing starts with F2 key
+			Component editorComp = table.getEditorComponent();
+			if( oldEditorComp == null && editorComp instanceof JTextField )
+				((JTextField)editorComp).selectAll();
+		}
+	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTextFieldUI.java

@@ -174,8 +174,6 @@ public class FlatTextFieldUI
 		defaultMargin = UIManager.getInsets( prefix + ".margin" );
 
 		LookAndFeel.installProperty( getComponent(), "opaque", false );
-
-		MigLayoutVisualPadding.install( getComponent() );
 	}
 
 	@Override
@@ -193,8 +191,6 @@ public class FlatTextFieldUI
 
 		oldStyleValues = null;
 		borderShared = null;
-
-		MigLayoutVisualPadding.uninstall( getComponent() );
 	}
 
 	@Override
@@ -204,6 +200,8 @@ public class FlatTextFieldUI
 		// necessary to update focus border and background
 		focusListener = new FlatUIUtils.RepaintFocusListener( getComponent(), null );
 		getComponent().addFocusListener( focusListener );
+
+		MigLayoutVisualPadding.install( getComponent() );
 	}
 
 	@Override
@@ -217,6 +215,8 @@ public class FlatTextFieldUI
 			getComponent().getDocument().removeDocumentListener( documentListener );
 			documentListener = null;
 		}
+
+		MigLayoutVisualPadding.uninstall( getComponent() );
 	}
 
 	@Override
@@ -239,7 +239,7 @@ public class FlatTextFieldUI
 			case COMPONENT_ROUND_RECT:
 			case OUTLINE:
 			case TEXT_FIELD_PADDING:
-				c.repaint();
+				HiDPIUtils.repaint( c );
 				break;
 
 			case MINIMUM_WIDTH:
@@ -250,38 +250,38 @@ public class FlatTextFieldUI
 			case STYLE_CLASS:
 				installStyle();
 				c.revalidate();
-				c.repaint();
+				HiDPIUtils.repaint( c );
 				break;
 
 			case TEXT_FIELD_LEADING_ICON:
 				leadingIcon = (e.getNewValue() instanceof Icon) ? (Icon) e.getNewValue() : null;
-				c.repaint();
+				HiDPIUtils.repaint( c );
 				break;
 
 			case TEXT_FIELD_TRAILING_ICON:
 				trailingIcon = (e.getNewValue() instanceof Icon) ? (Icon) e.getNewValue() : null;
-				c.repaint();
+				HiDPIUtils.repaint( c );
 				break;
 
 			case TEXT_FIELD_LEADING_COMPONENT:
 				uninstallLeadingComponent();
 				installLeadingComponent();
 				c.revalidate();
-				c.repaint();
+				HiDPIUtils.repaint( c );
 				break;
 
 			case TEXT_FIELD_TRAILING_COMPONENT:
 				uninstallTrailingComponent();
 				installTrailingComponent();
 				c.revalidate();
-				c.repaint();
+				HiDPIUtils.repaint( c );
 				break;
 
 			case TEXT_FIELD_SHOW_CLEAR_BUTTON:
 				uninstallClearButton();
 				installClearButton();
 				c.revalidate();
-				c.repaint();
+				HiDPIUtils.repaint( c );
 				break;
 
 			case "enabled":
@@ -815,7 +815,7 @@ debug*/
 		if( visible != clearButton.isVisible() ) {
 			clearButton.setVisible( visible );
 			c.revalidate();
-			c.repaint();
+			HiDPIUtils.repaint( c );
 		}
 	}
 

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTitlePane.java

@@ -33,9 +33,9 @@ import java.awt.Image;
 import java.awt.Insets;
 import java.awt.Point;
 import java.awt.Rectangle;
-import java.awt.Toolkit;
 import java.awt.Window;
 import java.awt.event.ActionListener;
+import java.awt.event.ComponentAdapter;
 import java.awt.event.ComponentEvent;
 import java.awt.event.ComponentListener;
 import java.awt.event.MouseEvent;
@@ -46,9 +46,9 @@ import java.awt.event.WindowEvent;
 import java.awt.geom.AffineTransform;
 import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
+import java.util.function.Function;
 import javax.accessibility.AccessibleContext;
 import javax.swing.BorderFactory;
 import javax.swing.Box;
@@ -57,7 +57,6 @@ import javax.swing.Icon;
 import javax.swing.JButton;
 import javax.swing.JComponent;
 import javax.swing.JDialog;
-import javax.swing.JInternalFrame;
 import javax.swing.JLabel;
 import javax.swing.JMenuBar;
 import javax.swing.JPanel;
@@ -66,6 +65,7 @@ import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
 import javax.swing.border.AbstractBorder;
 import javax.swing.border.Border;
+import javax.swing.plaf.ComponentUI;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.FlatSystemProperties;
 import com.formdev.flatlaf.ui.FlatNativeWindowBorder.WindowTopBorder;
@@ -89,16 +89,18 @@ import com.formdev.flatlaf.util.UIScale;
  * @uiDefault TitlePane.iconSize							Dimension
  * @uiDefault TitlePane.iconMargins							Insets
  * @uiDefault TitlePane.titleMargins						Insets
- * @uiDefault TitlePane.menuBarEmbedded						boolean
  * @uiDefault TitlePane.titleMinimumWidth					int
  * @uiDefault TitlePane.buttonMinimumWidth					int
  * @uiDefault TitlePane.buttonMaximizedHeight				int
+ * @uiDefault TitlePane.buttonsGap							int
+ * @uiDefault TitlePane.buttonsMargins						Insets
+ * @uiDefault TitlePane.buttonsFillVertically				boolean
  * @uiDefault TitlePane.centerTitle							boolean
  * @uiDefault TitlePane.centerTitleIfMenuBarEmbedded		boolean
  * @uiDefault TitlePane.showIconBesideTitle					boolean
+ * @uiDefault TitlePane.menuBarEmbedded						boolean
  * @uiDefault TitlePane.menuBarTitleGap						int
  * @uiDefault TitlePane.menuBarTitleMinimumGap				int
- * @uiDefault TitlePane.menuBarResizeHeight					int
  * @uiDefault TitlePane.closeIcon							Icon
  * @uiDefault TitlePane.iconifyIcon							Icon
  * @uiDefault TitlePane.maximizeIcon						Icon
@@ -109,7 +111,8 @@ import com.formdev.flatlaf.util.UIScale;
 public class FlatTitlePane
 	extends JComponent
 {
-	private static final String KEY_DEBUG_SHOW_RECTANGLES = "FlatLaf.debug.titlebar.showRectangles";
+	static final String KEY_DEBUG_SHOW_RECTANGLES = "FlatLaf.debug.titlebar.showRectangles";
+	private static final boolean isWindows_10 = SystemInfo.isWindows_10_orLater && !SystemInfo.isWindows_11_orLater;
 
 	/** @since 2.5 */ protected final Font titleFont;
 	protected final Color activeBackground;
@@ -123,15 +126,19 @@ public class FlatTitlePane
 	/** @since 2.5 */ protected final boolean showIconInDialogs;
 	/** @since 2 */ protected final int noIconLeftGap;
 	protected final Dimension iconSize;
+	/** @since 3.6 */ protected final Insets iconMargins;
+	/** @since 3.6 */ protected final Insets titleMargins;
 	/** @since 2.4 */ protected final int titleMinimumWidth;
 	/** @since 2.4 */ protected final int buttonMinimumWidth;
 	protected final int buttonMaximizedHeight;
+	/** @since 3.6 */ protected final int buttonsGap;
+	/** @since 3.6 */ protected final Insets buttonsMargins;
+	/** @since 3.6 */ protected final boolean buttonsFillVertically;
 	protected final boolean centerTitle;
 	protected final boolean centerTitleIfMenuBarEmbedded;
 	/** @since 2.4 */ protected final boolean showIconBesideTitle;
 	protected final int menuBarTitleGap;
 	/** @since 2.4 */ protected final int menuBarTitleMinimumGap;
-	/** @since 2.4 */ protected final int menuBarResizeHeight;
 
 	protected final JRootPane rootPane;
 	protected final String windowStyle;
@@ -146,16 +153,44 @@ public class FlatTitlePane
 	protected JButton restoreButton;
 	protected JButton closeButton;
 
+	private JComponent iconifyMaximizeGapComp;
+	private JComponent maximizeCloseGapComp;
+
 	protected Window window;
 
 	private final Handler handler;
 
+	/**
+	 * This panel handles mouse events if FlatLaf window decorations are used
+	 * without native window border. E.g. on Linux.
+	 * <p>
+	 * This panel usually has same bounds as the title pane,
+	 * except if fullWindowContent mode is enabled.
+	 * <p>
+	 * This panel is not a child of the title pane.
+	 * Instead it is added by FlatRootPaneUI to the layered pane at a layer
+	 * under the title pane and under the frame content.
+	 * The separation is necessary for fullWindowContent mode, where the title pane
+	 * is layered over the frame content (for title pane buttons), but the mousePanel
+	 * needs to be layered under the frame content so that components on content pane
+	 * can receive mouse events when located in title area.
+	 */
+	final JPanel mouseLayer;
+
+	/**
+	 * This panel paint a border at the top of the window in fullWindowContent mode,
+	 * if FlatLaf window decorations are enabled.
+	 * Only used on Windows 10.
+	 * <p>
+	 * This panel is not a child of the title pane.
+	 * Instead it is added by FlatRootPaneUI to the layered pane at a layer over all other layers.
+	 */
+	final JPanel windowTopBorderLayer;
+
 	public FlatTitlePane( JRootPane rootPane ) {
 		this.rootPane = rootPane;
 
-		Window w = SwingUtilities.getWindowAncestor( rootPane );
-		String defaultWindowStyle = (w != null && w.getType() == Window.Type.UTILITY) ? WINDOW_STYLE_SMALL : null;
-		windowStyle = clientProperty( rootPane, WINDOW_STYLE, defaultWindowStyle, String.class );
+		windowStyle = getWindowStyle( rootPane );
 
 		titleFont = FlatUIUtils.getSubUIFont( "TitlePane.font", windowStyle );
 		activeBackground = FlatUIUtils.getSubUIColor( "TitlePane.background", windowStyle );
@@ -170,15 +205,19 @@ public class FlatTitlePane
 		showIconInDialogs = FlatUIUtils.getSubUIBoolean( "TitlePane.showIconInDialogs", windowStyle, true );
 		noIconLeftGap = FlatUIUtils.getSubUIInt( "TitlePane.noIconLeftGap", windowStyle, 8 );
 		iconSize = FlatUIUtils.getSubUIDimension( "TitlePane.iconSize", windowStyle );
+		iconMargins = FlatUIUtils.getSubUIInsets( "TitlePane.iconMargins", windowStyle );
+		titleMargins = FlatUIUtils.getSubUIInsets( "TitlePane.titleMargins", windowStyle );
 		titleMinimumWidth = FlatUIUtils.getSubUIInt( "TitlePane.titleMinimumWidth", windowStyle, 60 );
 		buttonMinimumWidth = FlatUIUtils.getSubUIInt( "TitlePane.buttonMinimumWidth", windowStyle, 30 );
 		buttonMaximizedHeight = FlatUIUtils.getSubUIInt( "TitlePane.buttonMaximizedHeight", windowStyle, 0 );
+		buttonsGap = FlatUIUtils.getSubUIInt( "TitlePane.buttonsGap", windowStyle, 0 );
+		buttonsMargins = FlatUIUtils.getSubUIInsets( "TitlePane.buttonsMargins", windowStyle );
+		buttonsFillVertically = FlatUIUtils.getSubUIBoolean( "TitlePane.buttonsFillVertically", windowStyle, true );
 		centerTitle = FlatUIUtils.getSubUIBoolean( "TitlePane.centerTitle", windowStyle, false );
 		centerTitleIfMenuBarEmbedded = FlatUIUtils.getSubUIBoolean( "TitlePane.centerTitleIfMenuBarEmbedded", windowStyle, true );
 		showIconBesideTitle = FlatUIUtils.getSubUIBoolean( "TitlePane.showIconBesideTitle", windowStyle, false );
 		menuBarTitleGap = FlatUIUtils.getSubUIInt( "TitlePane.menuBarTitleGap", windowStyle, 40 );
 		menuBarTitleMinimumGap = FlatUIUtils.getSubUIInt( "TitlePane.menuBarTitleMinimumGap", windowStyle, 12 );
-		menuBarResizeHeight = FlatUIUtils.getSubUIInt( "TitlePane.menuBarResizeHeight", windowStyle, 4 );
 
 
 		handler = createHandler();
@@ -187,15 +226,28 @@ public class FlatTitlePane
 		addSubComponents();
 		activeChanged( true );
 
-		addMouseListener( handler );
-		addMouseMotionListener( handler );
+		mouseLayer = new JPanel();
+		mouseLayer.setOpaque( false );
+		mouseLayer.addMouseListener( handler );
+		mouseLayer.addMouseMotionListener( handler );
 
-		// necessary for closing window with double-click on icon
-		iconLabel.addMouseListener( handler );
+		if( isWindows_10 && FlatNativeWindowBorder.isSupported() ) {
+			windowTopBorderLayer = new JPanel();
+			windowTopBorderLayer.setVisible( false );
+			windowTopBorderLayer.setOpaque( false );
+			windowTopBorderLayer.setBorder( FlatUIUtils.nonUIResource( WindowTopBorder.getInstance() ) );
+		} else
+			windowTopBorderLayer = null;
 
 		applyComponentOrientation( rootPane.getComponentOrientation() );
 	}
 
+	static String getWindowStyle( JRootPane rootPane ) {
+		Window w = SwingUtilities.getWindowAncestor( rootPane );
+		String defaultWindowStyle = (w != null && w.getType() == Window.Type.UTILITY) ? WINDOW_STYLE_SMALL : null;
+		return clientProperty( rootPane, WINDOW_STYLE, defaultWindowStyle, String.class );
+	}
+
 	protected FlatTitlePaneBorder createTitlePaneBorder() {
 		return new FlatTitlePaneBorder();
 	}
@@ -213,8 +265,8 @@ public class FlatTitlePane
 				setUI( new FlatTitleLabelUI() );
 			}
 		};
-		iconLabel.setBorder( new FlatEmptyBorder( FlatUIUtils.getSubUIInsets( "TitlePane.iconMargins", windowStyle ) ) );
-		titleLabel.setBorder( new FlatEmptyBorder( FlatUIUtils.getSubUIInsets( "TitlePane.titleMargins", windowStyle ) ) );
+		iconLabel.setBorder( new FlatEmptyBorder( iconMargins ) );
+		titleLabel.setBorder( new FlatEmptyBorder( titleMargins ) );
 
 		leftPanel.setLayout( new BoxLayout( leftPanel, BoxLayout.LINE_AXIS ) );
 		leftPanel.setOpaque( false );
@@ -234,6 +286,11 @@ public class FlatTitlePane
 		setLayout( new BorderLayout() {
 			@Override
 			public void layoutContainer( Container target ) {
+				if( isFullWindowContent() ) {
+					super.layoutContainer( target );
+					return;
+				}
+
 				// compute available bounds
 				Insets insets = target.getInsets();
 				int x = insets.left;
@@ -247,7 +304,7 @@ public class FlatTitlePane
 				int titleWidth = w - leftWidth - buttonsWidth;
 				int minTitleWidth = UIScale.scale( titleMinimumWidth );
 
-				// increase minimum width if icon is show besides the title
+				// increase minimum width if icon is shown besides the title
 				Icon icon = titleLabel.getIcon();
 				if( icon != null ) {
 					Insets iconInsets = iconLabel.getInsets();
@@ -295,6 +352,9 @@ public class FlatTitlePane
 							horizontalGlue.getWidth(), titleLabel.getHeight() );
 					}
 				}
+
+				// clear hit-test cache
+				lastCaptionHitTestTime = 0;
 			}
 		} );
 
@@ -309,23 +369,33 @@ public class FlatTitlePane
 		restoreButton = createButton( "TitlePane.restoreIcon", "Restore", e -> restore() );
 		closeButton = createButton( "TitlePane.closeIcon", "Close", e -> close() );
 
+		iconifyMaximizeGapComp = createButtonsGapComp();
+		maximizeCloseGapComp = createButtonsGapComp();
+
 		// initially hide buttons that are only supported in frames
 		iconifyButton.setVisible( false );
 		maximizeButton.setVisible( false );
 		restoreButton.setVisible( false );
+		iconifyMaximizeGapComp.setVisible( false );
+		maximizeCloseGapComp.setVisible( false );
 
 		buttonPanel = new JPanel() {
 			@Override
 			public Dimension getPreferredSize() {
 				Dimension size = super.getPreferredSize();
+				int titleBarHeight = clientPropertyInt( rootPane, TITLE_BAR_HEIGHT, -1 );
+				if( titleBarHeight >= 0 )
+					return new Dimension( size.width, UIScale.scale( titleBarHeight ) );
+
 				if( buttonMaximizedHeight > 0 && isWindowMaximized() && !hasVisibleEmbeddedMenuBar( rootPane.getJMenuBar() ) ) {
 					// make title pane height smaller when frame is maximized
-					size = new Dimension( size.width, Math.min( size.height, UIScale.scale( buttonMaximizedHeight ) ) );
+					size = new Dimension( size.width, Math.min( size.height, UIScale.scale( buttonMaximizedHeight + buttonsMargins.top + buttonsMargins.bottom ) ) );
 				}
 				return size;
 			}
 		};
 		buttonPanel.setOpaque( false );
+		buttonPanel.setBorder( FlatUIUtils.nonUIResource( new FlatEmptyBorder( buttonsMargins ) ) );
 		buttonPanel.setLayout( new BoxLayout( buttonPanel, BoxLayout.LINE_AXIS ) );
 		if( rootPane.getWindowDecorationStyle() == JRootPane.FRAME ) {
 			// JRootPane.FRAME works only for frames (and not for dialogs)
@@ -334,10 +404,19 @@ public class FlatTitlePane
 			// later in frameStateChanged(), which is invoked from addNotify()
 
 			buttonPanel.add( iconifyButton );
+			buttonPanel.add( iconifyMaximizeGapComp );
 			buttonPanel.add( maximizeButton );
 			buttonPanel.add( restoreButton );
+			buttonPanel.add( maximizeCloseGapComp );
 		}
 		buttonPanel.add( closeButton );
+
+		ComponentListener l = new ComponentAdapter() {
+			@Override public void componentResized( ComponentEvent e ) { updateFullWindowContentButtonsBoundsProperty(); }
+			@Override public void componentMoved( ComponentEvent e ) { updateFullWindowContentButtonsBoundsProperty(); }
+		};
+		buttonPanel.addComponentListener( l );
+		addComponentListener( l );
 	}
 
 	protected JButton createButton( String iconKey, String accessibleName, ActionListener action ) {
@@ -345,7 +424,17 @@ public class FlatTitlePane
 			@Override
 			public Dimension getMinimumSize() {
 				// allow the button to shrink if space is rare
-				return new Dimension( UIScale.scale( buttonMinimumWidth ), super.getMinimumSize().height );
+				return new Dimension(
+					Math.min( UIScale.scale( buttonMinimumWidth ), super.getPreferredSize().width ),
+					super.getMinimumSize().height );
+			}
+			@Override
+			public Dimension getMaximumSize() {
+				// allow the button to fill whole button area height
+				// see also BasicMenuUI.getMaximumSize()
+				return buttonsFillVertically
+					? new Dimension( super.getMaximumSize().width, Short.MAX_VALUE )
+					: super.getMaximumSize();
 			}
 		};
 		button.setFocusable( false );
@@ -356,6 +445,14 @@ public class FlatTitlePane
 		return button;
 	}
 
+	private JComponent createButtonsGapComp() {
+		JComponent gapComp = new JPanel();
+		gapComp.setOpaque( false );
+		gapComp.setMinimumSize( new Dimension( 0, 0 ) );
+		gapComp.setPreferredSize( new Dimension( UIScale.scale( buttonsGap ), 0 ) );
+		return gapComp;
+	}
+
 	protected void activeChanged( boolean active ) {
 		Color background = clientPropertyColor( rootPane, TITLE_BAR_BACKGROUND, null );
 		Color foreground = clientPropertyColor( rootPane, TITLE_BAR_FOREGROUND, null );
@@ -377,6 +474,9 @@ public class FlatTitlePane
 		closeButton.setForeground( foreground );
 
 		// this is necessary because hover/pressed colors are derived from background color
+		// (since FlatWindowAbstractIcon now invokes FlatTitlePane.getBackground()
+		//  to get base color, this is no longer necessary, but keep it for compatibility;
+		//  e.g. for custom window icons)
 		iconifyButton.setBackground( background );
 		maximizeButton.setBackground( background );
 		restoreButton.setBackground( background );
@@ -417,7 +517,9 @@ public class FlatTitlePane
 
 	/** @since 3 */
 	protected void updateVisibility() {
-		titleLabel.setVisible( clientPropertyBoolean( rootPane, TITLE_BAR_SHOW_TITLE, true ) );
+		boolean isFullWindowContent = isFullWindowContent();
+		leftPanel.setVisible( !isFullWindowContent );
+		titleLabel.setVisible( clientPropertyBoolean( rootPane, TITLE_BAR_SHOW_TITLE, true ) && !isFullWindowContent );
 		closeButton.setVisible( clientPropertyBoolean( rootPane, TITLE_BAR_SHOW_CLOSE, true ) );
 
 		if( window instanceof Frame ) {
@@ -434,6 +536,13 @@ public class FlatTitlePane
 			maximizeButton.setVisible( false );
 			restoreButton.setVisible( false );
 		}
+
+		boolean iconifyVisible = iconifyButton.isVisible();
+		boolean maximizeVisible = maximizeButton.isVisible();
+		boolean restoreVisible = restoreButton.isVisible();
+		boolean closeVisible = closeButton.isVisible();
+		iconifyMaximizeGapComp.setVisible( iconifyVisible && (maximizeVisible || restoreVisible || closeVisible) );
+		maximizeCloseGapComp.setVisible( closeVisible && (maximizeVisible || restoreVisible) );
 	}
 
 	protected void updateIcon() {
@@ -443,7 +552,7 @@ public class FlatTitlePane
 
 		// get window images
 		List<Image> images = null;
-		if( clientPropertyBoolean( rootPane, TITLE_BAR_SHOW_ICON, defaultShowIcon ) ) {
+		if( clientPropertyBoolean( rootPane, TITLE_BAR_SHOW_ICON, defaultShowIcon ) && !isFullWindowContent() ) {
 			images = window.getIconImages();
 			if( images.isEmpty() ) {
 				// search in owners
@@ -468,6 +577,13 @@ public class FlatTitlePane
 		updateNativeTitleBarHeightAndHitTestSpotsLater();
 	}
 
+	void updateFullWindowContentButtonsBoundsProperty() {
+		Rectangle bounds = isFullWindowContent()
+			? new Rectangle( SwingUtilities.convertPoint( buttonPanel, 0, 0, rootPane ), buttonPanel.getSize() )
+			: null;
+		rootPane.putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_BOUNDS, bounds );
+	}
+
 	@Override
 	public void addNotify() {
 		super.addNotify();
@@ -522,6 +638,11 @@ public class FlatTitlePane
 		window.removeComponentListener( handler );
 	}
 
+	/** @since 3.4 */
+	protected boolean isFullWindowContent() {
+		return FlatRootPaneUI.isFullWindowContent( rootPane );
+	}
+
 	/**
 	 * Returns whether this title pane currently has a visible and embedded menubar.
 	 */
@@ -533,6 +654,9 @@ public class FlatTitlePane
 	 * Returns whether the menubar should be embedded into the title pane.
 	 */
 	protected boolean isMenuBarEmbedded() {
+		if( isFullWindowContent() )
+			return false;
+
 		// not storing value of "TitlePane.menuBarEmbedded" in class to allow changing at runtime
 		return FlatUIUtils.getBoolean( rootPane,
 			FlatSystemProperties.MENUBAR_EMBEDDED,
@@ -608,6 +732,10 @@ public class FlatTitlePane
 		doLayout();
 	}
 
+	void menuBarInvalidate() {
+		menuBarPlaceholder.invalidate();
+	}
+
 	@Override
 	public void paint( Graphics g ) {
 		super.paint( g );
@@ -616,21 +744,45 @@ public class FlatTitlePane
 			return;
 
 		if( debugTitleBarHeight > 0 ) {
+			// title bar height is measured from window top edge
+			int y = SwingUtilities.convertPoint( window, 0, debugTitleBarHeight, this ).y;
 			g.setColor( Color.green );
-			g.drawLine( 0, debugTitleBarHeight, getWidth(), debugTitleBarHeight );
-		}
-		if( debugHitTestSpots != null ) {
-			for( Rectangle r : debugHitTestSpots )
-				paintRect( g, Color.red, r );
-		}
-		paintRect( g, Color.cyan, debugCloseButtonBounds );
-		paintRect( g, Color.blue, debugAppIconBounds );
-		paintRect( g, Color.blue, debugMinimizeButtonBounds );
-		paintRect( g, Color.magenta, debugMaximizeButtonBounds );
-		paintRect( g, Color.cyan, debugCloseButtonBounds );
+			g.drawLine( 0, y, getWidth(), y );
 		}
 
-	private void paintRect( Graphics g, Color color, Rectangle r ) {
+		g.setColor( Color.red );
+		debugPaintComponentWithMouseListener( g, Color.red, rootPane.getLayeredPane(), 0, 0 );
+
+		debugPaintRect( g, Color.blue, debugAppIconBounds );
+		debugPaintRect( g, Color.blue, debugMinimizeButtonBounds );
+		debugPaintRect( g, Color.magenta, debugMaximizeButtonBounds );
+		debugPaintRect( g, Color.cyan, debugCloseButtonBounds );
+	}
+
+	private void debugPaintComponentWithMouseListener( Graphics g, Color color, Component c, int x, int y ) {
+		if( !c.isDisplayable() || !c.isVisible() || c == mouseLayer ||
+			c == iconifyButton || c == maximizeButton || c == restoreButton || c == closeButton )
+		  return;
+
+		if( c.getMouseListeners().length > 0 ||
+			c.getMouseMotionListeners().length > 0 ||
+			c.getMouseWheelListeners().length > 0 )
+		{
+			g.drawRect( x, y, c.getWidth(), c.getHeight() );
+			return;
+		}
+
+		if( c instanceof Container ) {
+			Rectangle titlePaneBoundsOnWindow = SwingUtilities.convertRectangle( this, new Rectangle( getSize() ), window );
+			for( Component child : ((Container)c).getComponents() ) {
+				Rectangle compBoundsOnWindow = SwingUtilities.convertRectangle( c, new Rectangle( c.getSize() ), window );
+				if( compBoundsOnWindow.intersects( titlePaneBoundsOnWindow ) )
+					debugPaintComponentWithMouseListener( g, color, child, x + child.getX(), y + child.getY() );
+			}
+		}
+	}
+
+	private void debugPaintRect( Graphics g, Color color, Rectangle r ) {
 		if( r == null )
 			return;
 
@@ -641,22 +793,20 @@ public class FlatTitlePane
 
 	@Override
 	protected void paintComponent( Graphics g ) {
-		// not storing value of "TitlePane.unifiedBackground" in class to allow changing at runtime
-		g.setColor( (UIManager.getBoolean( "TitlePane.unifiedBackground" ) &&
-				clientPropertyColor( rootPane, TITLE_BAR_BACKGROUND, null ) == null)
-			? FlatUIUtils.getParentBackground( this )
-			: getBackground() );
+		if( isFullWindowContent() )
+			return;
+
+		g.setColor( getBackground() );
 		g.fillRect( 0, 0, getWidth(), getHeight() );
 	}
 
-	protected void repaintWindowBorder() {
-		int width = rootPane.getWidth();
-		int height = rootPane.getHeight();
-		Insets insets = rootPane.getInsets();
-		rootPane.repaint( 0, 0, width, insets.top ); // top
-		rootPane.repaint( 0, 0, insets.left, height ); // left
-		rootPane.repaint( 0, height - insets.bottom, width, insets.bottom ); // bottom
-		rootPane.repaint( width - insets.right, 0, insets.right, height ); // right
+	@Override
+	public Color getBackground() {
+		// not storing value of "TitlePane.unifiedBackground" in class to allow changing at runtime
+		return (UIManager.getBoolean( "TitlePane.unifiedBackground" ) &&
+				clientPropertyColor( rootPane, TITLE_BAR_BACKGROUND, null ) == null)
+			? FlatUIUtils.getParentBackground( this )
+			: super.getBackground();
 	}
 
 	/**
@@ -728,7 +878,8 @@ public class FlatTitlePane
 		Rectangle oldMaximizedBounds = frame.getMaximizedBounds();
 		if( !hasNativeCustomDecoration() &&
 			(oldMaximizedBounds == null ||
-			 Objects.equals( oldMaximizedBounds, rootPane.getClientProperty( "_flatlaf.maximizedBounds" ) )) )
+			 Objects.equals( oldMaximizedBounds, rootPane.getClientProperty( "_flatlaf.maximizedBounds" ) )) &&
+			window.getGraphicsConfiguration() != null )
 		{
 			GraphicsConfiguration gc = window.getGraphicsConfiguration();
 
@@ -763,7 +914,7 @@ public class FlatTitlePane
 			// screen insets are in physical size, except for Java 15+
 			// (see https://bugs.openjdk.java.net/browse/JDK-8243925)
 			// and except for Java 8 on secondary screens where primary screen is scaled
-			Insets screenInsets = window.getToolkit().getScreenInsets( gc );
+			Insets screenInsets = FlatUIUtils.getScreenInsets( gc );
 
 			// maximized bounds are required in physical size, except for Java 15+
 			// (see https://bugs.openjdk.java.net/browse/JDK-8231564 and
@@ -835,10 +986,6 @@ public class FlatTitlePane
 			window.dispatchEvent( new WindowEvent( window, WindowEvent.WINDOW_CLOSING ) );
 	}
 
-	private boolean hasJBRCustomDecoration() {
-		return window != null && JBRCustomDecorations.hasCustomDecoration( window );
-	}
-
 	/**
 	 * Returns whether windows uses native window border and has custom decorations enabled.
 	 */
@@ -846,6 +993,10 @@ public class FlatTitlePane
 		return window != null && FlatNativeWindowBorder.hasCustomDecoration( window );
 	}
 
+	boolean isWindowTopBorderNeeded() {
+		return isWindows_10 && hasNativeCustomDecoration();
+	}
+
 	// used to invoke updateNativeTitleBarHeightAndHitTestSpots() only once from latest invokeLater()
 	private int laterCounter;
 
@@ -866,11 +1017,14 @@ public class FlatTitlePane
 			return;
 
 		int titleBarHeight = getHeight();
+		// title bar height must be measured from window top edge
+		// (when window is maximized, window y location is e.g. -11 and window top inset is 11)
+		for( Component c = this; c != window && c != null; c = c.getParent() )
+			titleBarHeight += c.getY();
 		// slightly reduce height so that component receives mouseExit events
 		if( titleBarHeight > 0 )
 			titleBarHeight--;
 
-		List<Rectangle> hitTestSpots = new ArrayList<>();
 		Rectangle appIconBounds = null;
 
 		if( !showIconBesideTitle && iconLabel.isVisible() ) {
@@ -896,9 +1050,6 @@ public class FlatTitlePane
 					iconBounds.width += iconInsets.right;
 			}
 
-			if( hasJBRCustomDecoration() )
-				hitTestSpots.add( iconBounds );
-			else
 			appIconBounds = iconBounds;
 		} else if( showIconBesideTitle && titleLabel.getIcon() != null && titleLabel.getUI() instanceof FlatTitleLabelUI ) {
 			FlatTitleLabelUI ui = (FlatTitleLabelUI) titleLabel.getUI();
@@ -927,78 +1078,21 @@ public class FlatTitlePane
 				iconR.width += 2;
 				iconR.height += 2;
 
-				if( hasJBRCustomDecoration() )
-					hitTestSpots.add( iconR );
-				else
 				appIconBounds = iconR;
 			}
 		}
 
-		Rectangle r = getNativeHitTestSpot( buttonPanel );
-		if( r != null )
-			hitTestSpots.add( r );
-
-		JMenuBar menuBar = rootPane.getJMenuBar();
-		if( hasVisibleEmbeddedMenuBar( menuBar ) ) {
-			r = getNativeHitTestSpot( menuBar );
-			if( r != null ) {
-				// if frame is resizable and not maximized, make menu bar hit test spot smaller at top
-				// to have a small area above the menu bar to resize the window
-				if( window instanceof Frame && ((Frame)window).isResizable() && !isWindowMaximized() ) {
-					// limit to 8, because Windows does not use a larger height
-					int resizeHeight = UIScale.scale( Math.min( menuBarResizeHeight, 8 ) );
-					r.y += resizeHeight;
-					r.height -= resizeHeight;
-				}
-
-				int count = menuBar.getComponentCount();
-				for( int i = count - 1; i >= 0; i-- ) {
-					Component c = menuBar.getComponent( i );
-					if( c instanceof Box.Filler ||
-						(c instanceof JComponent && clientPropertyBoolean( (JComponent) c, COMPONENT_TITLE_BAR_CAPTION, false ) ) )
-					{
-						// If menu bar is embedded and contains a horizontal glue or caption component,
-						// then split the hit test spot so that
-						// the glue/caption component area can be used to move the window.
-
-						Point glueLocation = SwingUtilities.convertPoint( c, 0, 0, window );
-						int x2 = glueLocation.x + c.getWidth();
-						Rectangle r2;
-						if( getComponentOrientation().isLeftToRight() ) {
-							r2 = new Rectangle( x2, r.y, (r.x + r.width) - x2, r.height );
-
-							r.width = glueLocation.x - r.x;
-						} else {
-							r2 = new Rectangle( r.x, r.y, glueLocation.x - r.x, r.height );
-
-							r.width = (r.x + r.width) - x2;
-							r.x = x2;
-						}
-						if( r2.width > 0 )
-							hitTestSpots.add( r2 );
-					}
-				}
-
-				hitTestSpots.add( r );
-			}
-		}
-
-		// allow internal frames in layered pane to be moved/resized when placed over title bar
-		for( Component c : rootPane.getLayeredPane().getComponents() ) {
-			r = (c instanceof JInternalFrame) ? getNativeHitTestSpot( (JInternalFrame) c ) : null;
-			if( r != null )
-				hitTestSpots.add( r );
-		}
-
 		Rectangle minimizeButtonBounds = boundsInWindow( iconifyButton );
 		Rectangle maximizeButtonBounds = boundsInWindow( maximizeButton.isVisible() ? maximizeButton : restoreButton );
 		Rectangle closeButtonBounds = boundsInWindow( closeButton );
 
+		// clear hit-test cache
+		lastCaptionHitTestTime = 0;
+
 		FlatNativeWindowBorder.setTitleBarHeightAndHitTestSpots( window, titleBarHeight,
-			hitTestSpots, appIconBounds, minimizeButtonBounds, maximizeButtonBounds, closeButtonBounds );
+			this::captionHitTest, appIconBounds, minimizeButtonBounds, maximizeButtonBounds, closeButtonBounds );
 
 		debugTitleBarHeight = titleBarHeight;
-		debugHitTestSpots = hitTestSpots;
 		debugAppIconBounds = appIconBounds;
 		debugMinimizeButtonBounds = minimizeButtonBounds;
 		debugMaximizeButtonBounds = maximizeButtonBounds;
@@ -1013,18 +1107,123 @@ public class FlatTitlePane
 			: null;
 	}
 
-	protected Rectangle getNativeHitTestSpot( JComponent c ) {
-		Dimension size = c.getSize();
-		if( size.width <= 0 || size.height <= 0 )
-			return null;
-
-		Point location = SwingUtilities.convertPoint( c, 0, 0, window );
-		Rectangle r = new Rectangle( location, size );
-		return r;
+	/**
+	 * Returns whether there is a component at the given location, that processes
+	 * mouse events. E.g. buttons, menus, etc.
+	 * <p>
+	 * Note:
+	 * <ul>
+	 *   <li>This method is invoked often when mouse is moved over window title bar area
+	 *       and should therefore return quickly.
+	 *   <li>This method is invoked on 'AWT-Windows' thread (not 'AWT-EventQueue' thread)
+	 *       while processing Windows messages.
+	 *       It <b>must not</b> change any component property or layout because this could cause a dead lock.
+	 * </ul>
+	 */
+	private boolean captionHitTest( Point pt ) {
+		// Windows invokes this method every ~200ms, even if the mouse has not moved
+		long time = System.currentTimeMillis();
+		if( pt.x == lastCaptionHitTestX && pt.y == lastCaptionHitTestY && time < lastCaptionHitTestTime + 300 ) {
+			lastCaptionHitTestTime = time;
+			return lastCaptionHitTestResult;
 		}
 
+		// convert pt from window coordinates to layeredPane coordinates
+		Component layeredPane = rootPane.getLayeredPane();
+		int x = pt.x;
+		int y = pt.y;
+		for( Component c = layeredPane; c != window && c != null; c = c.getParent() ) {
+			x -= c.getX();
+			y -= c.getY();
+		}
+
+		lastCaptionHitTestX = pt.x;
+		lastCaptionHitTestY = pt.y;
+		lastCaptionHitTestTime = time;
+		lastCaptionHitTestResult = isTitleBarCaptionAt( layeredPane, x, y );
+		return lastCaptionHitTestResult;
+	}
+
+	private boolean isTitleBarCaptionAt( Component c, int x, int y ) {
+		if( !c.isDisplayable() || !c.isVisible() || !contains( c, x, y ) || c == mouseLayer )
+			return true; // continue checking with next component
+
+		// check enabled component that has mouse listeners
+		if( c.isEnabled() &&
+			(c.getMouseListeners().length > 0 ||
+			 c.getMouseMotionListeners().length > 0) )
+		{
+			if( !(c instanceof JComponent) )
+				return false; // assume that this is not a caption because the component has mouse listeners
+
+			// check client property boolean value
+			Object caption = ((JComponent)c).getClientProperty( COMPONENT_TITLE_BAR_CAPTION );
+			if( caption instanceof Boolean )
+				return (boolean) caption;
+
+			// if component is not fully layouted, do not invoke function
+			// because it is too dangerous that the function tries to layout the component,
+			// which could cause a dead lock
+			if( !c.isValid() ) {
+				// revalidate if necessary so that it is valid when invoked again later
+				EventQueue.invokeLater( () -> {
+					Window w = SwingUtilities.windowForComponent( c );
+					if( w != null )
+						w.revalidate();
+					else
+						c.revalidate();
+				} );
+
+				return false; // assume that this is not a caption because the component has mouse listeners
+			}
+
+			if( caption instanceof Function ) {
+				// check client property function value
+				@SuppressWarnings( "unchecked" )
+				Function<Point, Boolean> hitTest = (Function<Point, Boolean>) caption;
+				Boolean result = hitTest.apply( new Point( x, y ) );
+				if( result != null )
+					return result;
+			} else {
+				// check component UI
+				ComponentUI ui = JavaCompatibility2.getUI( (JComponent) c );
+				if( !(ui instanceof TitleBarCaptionHitTest) )
+					return false; // assume that this is not a caption because the component has mouse listeners
+
+				Boolean result = ((TitleBarCaptionHitTest)ui).isTitleBarCaptionAt( x, y );
+				if( result != null )
+					return result;
+			}
+
+			// else continue checking children
+		}
+
+		// check children
+		if( c instanceof Container ) {
+			for( Component child : ((Container)c).getComponents() ) {
+				if( !isTitleBarCaptionAt( child, x - child.getX(), y - child.getY() ) )
+					return false;
+			}
+		}
+		return true;
+	}
+
+	/**
+	 * Same as {@link Component#contains(int, int)}, but not using that method
+	 * because it may be overridden by custom components and invoke code that
+	 * tries to request AWT tree lock on 'AWT-Windows' thread.
+	 * This could freeze the application if AWT tree is already locked on 'AWT-EventQueue' thread.
+	 */
+	private boolean contains( Component c, int x, int y ) {
+		return x >= 0 && y >= 0 && x < c.getWidth() && y < c.getHeight();
+	}
+
+	private int lastCaptionHitTestX;
+	private int lastCaptionHitTestY;
+	private long lastCaptionHitTestTime;
+	private boolean lastCaptionHitTestResult;
+
 	private int debugTitleBarHeight;
-	private List<Rectangle> debugHitTestSpots;
 	private Rectangle debugAppIconBounds;
 	private Rectangle debugMinimizeButtonBounds;
 	private Rectangle debugMaximizeButtonBounds;
@@ -1047,7 +1246,7 @@ public class FlatTitlePane
 			} else if( borderColor != null && (rootPane.getJMenuBar() == null || !rootPane.getJMenuBar().isVisible()) )
 				insets.bottom += UIScale.scale( 1 );
 
-			if( !SystemInfo.isWindows_11_orLater && hasNativeCustomDecoration() && !isWindowMaximized() )
+			if( isWindowTopBorderNeeded() && !isWindowMaximized() )
 				insets = FlatUIUtils.addInsets( insets, WindowTopBorder.getInstance().getBorderInsets() );
 
 			return insets;
@@ -1066,7 +1265,7 @@ public class FlatTitlePane
 				FlatUIUtils.paintFilledRectangle( g, borderColor, x, y + height - lineHeight, width, lineHeight );
 			}
 
-			if( !SystemInfo.isWindows_11_orLater && hasNativeCustomDecoration() && !isWindowMaximized() )
+			if( isWindowTopBorderNeeded() && !isWindowMaximized() && !isFullWindowContent() )
 				WindowTopBorder.getInstance().paintBorder( c, g, x, y, width, height );
 		}
 
@@ -1122,7 +1321,7 @@ public class FlatTitlePane
 				}
 			}
 
-			// compute icon width and gap (if icon is show besides the title)
+			// compute icon width and gap (if icon is shown besides the title)
 			int iconTextGap = 0;
 			int iconWidthAndGap = 0;
 			if( icon != null ) {
@@ -1131,7 +1330,7 @@ public class FlatTitlePane
 				iconWidthAndGap = icon.getIconWidth() + iconTextGap;
 			}
 
-			// layout title and icon (if show besides the title)
+			// layout title and icon (if shown besides the title)
 			String clippedText = SwingUtilities.layoutCompoundLabel( label, fontMetrics, text, icon,
 				label.getVerticalAlignment(), label.getHorizontalAlignment(),
 				label.getVerticalTextPosition(), label.getHorizontalTextPosition(),
@@ -1230,10 +1429,7 @@ public class FlatTitlePane
 			activeChanged( true );
 			updateNativeTitleBarHeightAndHitTestSpots();
 
-			if( !SystemInfo.isWindows_11_orLater && hasNativeCustomDecoration() )
-				WindowTopBorder.getInstance().repaintBorder( FlatTitlePane.this );
-
-			repaintWindowBorder();
+			repaintBorder();
 		}
 
 		@Override
@@ -1241,10 +1437,22 @@ public class FlatTitlePane
 			activeChanged( false );
 			updateNativeTitleBarHeightAndHitTestSpots();
 
-			if( !SystemInfo.isWindows_11_orLater && hasNativeCustomDecoration() )
+			repaintBorder();
+		}
+
+		private void repaintBorder() {
+			// Windows 10 top border
+			if( windowTopBorderLayer != null && windowTopBorderLayer.isShowing())
+				WindowTopBorder.getInstance().repaintBorder( windowTopBorderLayer );
+			else if( isWindowTopBorderNeeded() && !isWindowMaximized() && !isFullWindowContent() )
 				WindowTopBorder.getInstance().repaintBorder( FlatTitlePane.this );
 
-			repaintWindowBorder();
+			// Window border used for non-native window decorations
+			if( rootPane.getBorder() instanceof FlatRootPaneUI.FlatWindowBorder ) {
+				// not repainting four areas on the four sides because RepaintManager
+				// unions dirty regions, which also results in repaint of whole rootpane
+				rootPane.repaint();
+			}
 		}
 
 		@Override
@@ -1264,24 +1472,11 @@ debug*/
 
 		private Point dragOffset;
 		private boolean linuxNativeMove;
-		private long lastSingleClickWhen;
 
 		@Override
 		public void mouseClicked( MouseEvent e ) {
-			// on Linux, when using native library, the mouse clicked event
-			// is usually not sent and maximize/restore is done in mouse pressed event
-			// this check is here for the case that a mouse clicked event comes thru for some reason
-			if( linuxNativeMove && SystemInfo.isLinux && FlatNativeLinuxLibrary.isWMUtilsSupported( window ) ) {
-				// see comment in mousePressed()
-				if( lastSingleClickWhen != 0 && (e.getWhen() - lastSingleClickWhen) <= getMultiClickInterval() ) {
-					lastSingleClickWhen = 0;
-					maximizeOrRestore();
-				}
-				return;
-			}
-
 			if( e.getClickCount() == 2 && SwingUtilities.isLeftMouseButton( e ) ) {
-				if( e.getSource() == iconLabel ) {
+				if( SwingUtilities.getDeepestComponentAt( FlatTitlePane.this, e.getX(), e.getY() ) == iconLabel ) {
 					// double-click on icon closes window
 					close();
 				} else if( !hasNativeCustomDecoration() ) {
@@ -1308,44 +1503,8 @@ debug*/
 			if( !SwingUtilities.isLeftMouseButton( e ) )
 				return;
 
-			dragOffset = SwingUtilities.convertPoint( FlatTitlePane.this, e.getPoint(), window );
+			dragOffset = SwingUtilities.convertPoint( mouseLayer, e.getPoint(), window );
 			linuxNativeMove = false;
-
-			// on Linux, move or maximize/restore window
-			if( SystemInfo.isLinux && FlatNativeLinuxLibrary.isWMUtilsSupported( window ) ) {
-				// The fired Java mouse events, when doing a double-click and the first click
-				// sends a _NET_WM_MOVERESIZE message, are different for various Linux distributions:
-				//   CentOS 7      (GNOME 3.28.2, X11):   PRESSED(clickCount=1) PRESSED(clickCount=2) RELEASED(clickCount=2)
-				//   Ubuntu 20.04  (GNOME 3.36.1, X11):   PRESSED(clickCount=1) PRESSED(clickCount=2) RELEASED(clickCount=2)
-				//   Ubuntu 22.04  (GNOME 42.2, Wayland): PRESSED(clickCount=1)                       RELEASED(clickCount=1) CLICKED(clickCount=1)
-				//   Kubuntu 22.04 (KDE 5.24.4, X11):     PRESSED(clickCount=1) PRESSED(clickCount=1) RELEASED(clickCount=1)
-
-				// double-click is not always recognized in Java when using _NET_WM_MOVERESIZE message
-				int clickCount = e.getClickCount();
-				if( clickCount == 1 && lastSingleClickWhen != 0 && (e.getWhen() - lastSingleClickWhen) <= getMultiClickInterval() )
-					clickCount = 2;
-
-				switch( clickCount ) {
-					case 1:
-						// move window via _NET_WM_MOVERESIZE message
-						e.consume();
-						linuxNativeMove = FlatNativeLinuxLibrary.moveOrResizeWindow( window, e, FlatNativeLinuxLibrary.MOVE );
-						lastSingleClickWhen = e.getWhen();
-						break;
-
-					case 2:
-						// maximize/restore on double-click
-						// also done here because no mouse clicked event is sent when using _NET_WM_MOVERESIZE message
-						lastSingleClickWhen = 0;
-						maximizeOrRestore();
-						break;
-				}
-			}
-		}
-
-		private int getMultiClickInterval() {
-			Object value = Toolkit.getDefaultToolkit().getDesktopProperty( "awt.multiClickInterval" );
-			return (value instanceof Integer) ? (Integer) value : 500;
 		}
 
 		@Override public void mouseReleased( MouseEvent e ) {}
@@ -1368,6 +1527,13 @@ debug*/
 			if( hasNativeCustomDecoration() )
 				return; // do nothing if having native window border
 
+			// on Linux, move window using window manager
+			if( SystemInfo.isLinux && FlatNativeLinuxLibrary.isWMUtilsSupported( window ) ) {
+				linuxNativeMove = FlatNativeLinuxLibrary.moveOrResizeWindow( window, e, FlatNativeLinuxLibrary.MOVE );
+				if( linuxNativeMove )
+					return;
+			}
+
 			// restore window if it is maximized
 			if( window instanceof Frame ) {
 				Frame frame = (Frame) window;
@@ -1421,4 +1587,36 @@ debug*/
 		@Override public void componentMoved( ComponentEvent e ) {}
 		@Override public void componentHidden( ComponentEvent e ) {}
 	}
+
+	//---- interface TitleBarCaptionHitTest -----------------------------------
+
+	/**
+	 * For custom components use {@link FlatClientProperties#COMPONENT_TITLE_BAR_CAPTION}
+	 * instead of this interface.
+	 *
+	 * @since 3.4
+	 */
+	public interface TitleBarCaptionHitTest {
+		/**
+		 * Invoked for a component that is enabled and has mouse listeners,
+		 * to check whether it processes mouse input at the given x/y location.
+		 * Useful for components that do not use mouse input on whole component bounds.
+		 * E.g. a tabbed pane with a few tabs has some empty space beside the tabs
+		 * that can be used to move the window.
+		 * <p>
+		 * Note:
+		 * <ul>
+		 *   <li>This method is invoked often when mouse is moved over window title bar area
+		 *       and should therefore return quickly.
+		 *   <li>This method is invoked on 'AWT-Windows' thread (not 'AWT-EventQueue' thread)
+		 *       while processing Windows messages.
+		 *       It <b>must not</b> change any component property or layout because this could cause a dead lock.
+		 * </ul>
+		 *
+		 * @return {@code true} if the component is not interested in mouse input at the given location
+		 *         {@code false} if the component wants process mouse input at the given location
+		 *         {@code null} if the component children should be checked
+		 */
+		Boolean isTitleBarCaptionAt( int x, int y );
+	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatToggleButtonUI.java

@@ -26,6 +26,7 @@ import javax.swing.*;
 import javax.swing.plaf.ComponentUI;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.UnknownStyleException;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.UIScale;
 
 /**
@@ -159,14 +160,14 @@ public class FlatToggleButtonUI
 					b.revalidate();
 				}
 
-				b.repaint();
+				HiDPIUtils.repaint( b );
 				break;
 
 			case TAB_BUTTON_UNDERLINE_PLACEMENT:
 			case TAB_BUTTON_UNDERLINE_HEIGHT:
 			case TAB_BUTTON_UNDERLINE_COLOR:
 			case TAB_BUTTON_SELECTED_BACKGROUND:
-				b.repaint();
+				HiDPIUtils.repaint( b );
 				break;
 		}
 	}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatToolBarSeparatorUI.java

@@ -18,6 +18,7 @@ package com.formdev.flatlaf.ui;
 
 import static com.formdev.flatlaf.util.UIScale.scale;
 import java.awt.Color;
+import java.awt.Container;
 import java.awt.Dimension;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
@@ -35,6 +36,7 @@ import javax.swing.plaf.basic.BasicToolBarSeparatorUI;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
 
 /**
@@ -130,7 +132,7 @@ public class FlatToolBarSeparatorUI
 				} else
 					installStyle( s );
 				s.revalidate();
-				s.repaint();
+				HiDPIUtils.repaint( s );
 				break;
 		}
 	}
@@ -173,6 +175,12 @@ public class FlatToolBarSeparatorUI
 		if( size != null )
 			return scale( size );
 
+		// get separator width
+		int separatorWidth = this.separatorWidth;
+		FlatToolBarUI toolBarUI = getToolBarUI( c );
+		if( toolBarUI != null && toolBarUI.separatorWidth != null )
+			separatorWidth = toolBarUI.separatorWidth;
+
 		// make sure that gap on left and right side of line have same size
 		int sepWidth = (scale( (separatorWidth - LINE_WIDTH) / 2 ) * 2) + scale( LINE_WIDTH );
 
@@ -196,6 +204,12 @@ public class FlatToolBarSeparatorUI
 		float lineWidth = scale( 1f );
 		float offset = scale( 2f );
 
+		// get separator color
+		Color separatorColor = this.separatorColor;
+		FlatToolBarUI toolBarUI = getToolBarUI( c );
+		if( toolBarUI != null && toolBarUI.separatorColor != null )
+			separatorColor = toolBarUI.separatorColor;
+
 		Object[] oldRenderingHints = FlatUIUtils.setRenderingHints( g );
 		g.setColor( separatorColor );
 
@@ -210,4 +224,11 @@ public class FlatToolBarSeparatorUI
 	private boolean isVertical( JComponent c ) {
 		return ((JToolBar.Separator)c).getOrientation() == SwingConstants.VERTICAL;
 	}
+
+	private FlatToolBarUI getToolBarUI( JComponent c ) {
+		Container parent = c.getParent();
+		return (parent instanceof JToolBar && ((JToolBar)parent).getUI() instanceof FlatToolBarUI)
+			? (FlatToolBarUI) ((JToolBar)parent).getUI()
+			: null;
+	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatToolBarUI.java

@@ -47,6 +47,7 @@ import javax.swing.plaf.basic.BasicToolBarUI;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.UIScale;
 
@@ -82,7 +83,7 @@ import com.formdev.flatlaf.util.UIScale;
  */
 public class FlatToolBarUI
 	extends BasicToolBarUI
-	implements StyleableUI
+	implements StyleableUI, FlatTitlePane.TitleBarCaptionHitTest
 {
 	/** @since 1.4 */ @Styleable protected boolean focusableButtons;
 	/** @since 2 */ @Styleable protected boolean arrowKeysOnlyNavigation;
@@ -93,6 +94,10 @@ public class FlatToolBarUI
 	@Styleable protected Insets borderMargins;
 	@Styleable protected Color gripColor;
 
+	// for FlatToolBarSeparatorUI
+	/** @since 3.3 */ @Styleable protected Integer separatorWidth;
+	/** @since 3.3 */ @Styleable protected Color separatorColor;
+
 	private FocusTraversalPolicy focusTraversalPolicy;
 	private Boolean oldFloatable;
 	private Map<String, Object> oldStyleValues;
@@ -439,7 +444,7 @@ public class FlatToolBarUI
 
 		// repaint button group
 		if( gr != null )
-			toolBar.repaint( gr );
+			HiDPIUtils.repaint(toolBar, gr );
 	}
 
 	private ButtonGroup getButtonGroup( AbstractButton b ) {
@@ -449,6 +454,15 @@ public class FlatToolBarUI
 			: null;
 	}
 
+	//---- interface FlatTitlePane.TitleBarCaptionHitTest ----
+
+	/** @since 3.4 */
+	@Override
+	public Boolean isTitleBarCaptionAt( int x, int y ) {
+		// necessary because BasicToolBarUI adds some mouse listeners for dragging when toolbar is floatable
+		return null; // check children
+	}
+
 	//---- class FlatToolBarFocusTraversalPolicy ------------------------------
 
 	/**
@@ -517,8 +531,11 @@ public class FlatToolBarUI
 
 		private Component getRecentComponent( Container aContainer, boolean first ) {
 			// if moving focus into the toolbar, focus recently focused toolbar button
-			if( focusedCompIndex >= 0 && focusedCompIndex < toolBar.getComponentCount() )
-				return toolBar.getComponent( focusedCompIndex );
+			if( focusedCompIndex >= 0 && focusedCompIndex < toolBar.getComponentCount() ) {
+				Component c = toolBar.getComponent( focusedCompIndex );
+				if( accept( c ) )
+					return c;
+			}
 
 			return first
 				? super.getFirstComponent( aContainer )

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatToolTipUI.java

@@ -61,7 +61,7 @@ public class FlatToolTipUI
 		super.installUI( c );
 
 		// update HTML renderer if necessary
-		FlatLabelUI.updateHTMLRenderer( c, ((JToolTip)c).getTipText(), false );
+		FlatHTML.updateRendererCSSFontBaseSize( c );
 	}
 
 	@Override
@@ -81,11 +81,7 @@ public class FlatToolTipUI
 	/** @since 2.0.1 */
 	@Override
 	public void propertyChange( PropertyChangeEvent e ) {
-		String name = e.getPropertyName();
-		if( name == "tiptext" || name == "font" || name == "foreground" ) {
-			JToolTip toolTip = (JToolTip) e.getSource();
-			FlatLabelUI.updateHTMLRenderer( toolTip, toolTip.getTipText(), false );
-		}
+		FlatHTML.propertyChange( e );
 	}
 
 	@Override

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTreeUI.java

@@ -47,6 +47,7 @@ import javax.swing.tree.DefaultTreeCellRenderer;
 import javax.swing.tree.TreePath;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.UIScale;
 
@@ -101,9 +102,11 @@ import com.formdev.flatlaf.util.UIScale;
  * @uiDefault Tree.selectionForeground				Color
  * @uiDefault Tree.selectionInactiveBackground		Color
  * @uiDefault Tree.selectionInactiveForeground		Color
+ * @uiDefault Tree.alternateRowColor				Color
  * @uiDefault Tree.selectionInsets					Insets
  * @uiDefault Tree.selectionArc						int
  * @uiDefault Tree.wideSelection					boolean
+ * @uiDefault Tree.wideCellRenderer					boolean
  * @uiDefault Tree.showCellFocusIndicator			boolean
  * @uiDefault Tree.showDefaultIcons					boolean
  *
@@ -140,9 +143,11 @@ public class FlatTreeUI
 	@Styleable protected Color selectionInactiveBackground;
 	@Styleable protected Color selectionInactiveForeground;
 	@Styleable protected Color selectionBorderColor;
+	/** @since 3.6 */ @Styleable protected Color alternateRowColor;
 	/** @since 3 */ @Styleable protected Insets selectionInsets;
 	/** @since 3 */ @Styleable protected int selectionArc;
 	@Styleable protected boolean wideSelection;
+	/** @since 3.6 */ @Styleable protected boolean wideCellRenderer;
 	@Styleable protected boolean showCellFocusIndicator;
 	/** @since 3 */ protected boolean showDefaultIcons;
 
@@ -191,9 +196,11 @@ public class FlatTreeUI
 		selectionInactiveBackground = UIManager.getColor( "Tree.selectionInactiveBackground" );
 		selectionInactiveForeground = UIManager.getColor( "Tree.selectionInactiveForeground" );
 		selectionBorderColor = UIManager.getColor( "Tree.selectionBorderColor" );
+		alternateRowColor = UIManager.getColor( "Tree.alternateRowColor" );
 		selectionInsets = UIManager.getInsets( "Tree.selectionInsets" );
 		selectionArc = UIManager.getInt( "Tree.selectionArc" );
 		wideSelection = UIManager.getBoolean( "Tree.wideSelection" );
+		wideCellRenderer = UIManager.getBoolean( "Tree.wideCellRenderer" );
 		showCellFocusIndicator = UIManager.getBoolean( "Tree.showCellFocusIndicator" );
 		showDefaultIcons = UIManager.getBoolean( "Tree.showDefaultIcons" );
 
@@ -226,6 +233,7 @@ public class FlatTreeUI
 		selectionInactiveBackground = null;
 		selectionInactiveForeground = null;
 		selectionBorderColor = null;
+		alternateRowColor = null;
 
 		defaultLeafIcon = null;
 		defaultClosedIcon = null;
@@ -309,8 +317,9 @@ public class FlatTreeUI
 			if( e.getSource() == tree ) {
 				switch( e.getPropertyName() ) {
 					case TREE_WIDE_SELECTION:
+					case TREE_WIDE_CELL_RENDERER:
 					case TREE_PAINT_SELECTION:
-						tree.repaint();
+						HiDPIUtils.repaint( tree );
 						break;
 
 					case "dropLocation":
@@ -325,7 +334,7 @@ public class FlatTreeUI
 					case STYLE_CLASS:
 						installStyle();
 						tree.revalidate();
-						tree.repaint();
+						HiDPIUtils.repaint( tree );
 						break;
 
 					case "enabled":
@@ -353,7 +362,7 @@ public class FlatTreeUI
 
 		Rectangle r = tree.getPathBounds( loc.getPath() );
 		if( r != null )
-			tree.repaint( 0, r.y, tree.getWidth(), r.height );
+			HiDPIUtils.repaint( tree, 0, r.y, tree.getWidth(), r.height );
 	}
 
 	@Override
@@ -370,14 +379,14 @@ public class FlatTreeUI
 			{
 				if( changedPaths.length > 4 ) {
 					// same is done in BasicTreeUI.Handler.valueChanged()
-					tree.repaint();
+					HiDPIUtils.repaint( tree );
 				} else {
 					int arc = (int) Math.ceil( UIScale.scale( selectionArc / 2f ) );
 
 					for( TreePath path : changedPaths ) {
 						Rectangle r = getPathBounds( tree, path );
 						if( r != null )
-							tree.repaint( r.x, r.y - arc, r.width, r.height + (arc * 2) );
+							HiDPIUtils.repaint( tree, r.x, r.y - arc, r.width, r.height + (arc * 2) );
 					}
 				}
 			}
@@ -568,7 +577,27 @@ public class FlatTreeUI
 		boolean isEditing = (editingComponent != null && editingRow == row);
 		boolean isSelected = tree.isRowSelected( row );
 		boolean isDropRow = isDropRow( row );
-		boolean needsSelectionPainting = (isSelected || isDropRow) && isPaintSelection();
+
+		// paint alternating rows
+		if( alternateRowColor != null && row % 2 != 0 ) {
+			g.setColor( alternateRowColor );
+
+			float arc = UIScale.scale( selectionArc / 2f );
+			FlatUIUtils.paintSelection( (Graphics2D) g, 0, bounds.y, tree.getWidth(), bounds.height,
+				UIScale.scale( selectionInsets ), arc, arc, arc, arc, 0 );
+		}
+
+		// update bounds for wide cell renderer
+		if( isWideSelection() && isWideCellRenderer() ) {
+			Rectangle wideBounds = new Rectangle( bounds );
+			if( tree.getComponentOrientation().isLeftToRight() )
+				wideBounds.width = tree.getWidth() - bounds.x - insets.right;
+			else {
+				wideBounds.x = insets.left;
+				wideBounds.width = bounds.x + bounds.width - insets.left;
+			}
+			bounds = wideBounds;
+		}
 
 		// do not paint row if editing
 		if( isEditing ) {
@@ -578,7 +607,7 @@ public class FlatTreeUI
 			if( isSelected && isWideSelection() ) {
 				Color oldColor = g.getColor();
 				g.setColor( selectionInactiveBackground );
-				paintWideSelection( g, bounds, row );
+				paintWideSelection( g, bounds, row, false );
 				g.setColor( oldColor );
 			}
 			return;
@@ -598,7 +627,7 @@ public class FlatTreeUI
 
 		// renderer background/foreground
 		Color oldBackgroundSelectionColor = null;
-		if( isSelected && !hasFocus && !isDropRow ) {
+		if( isSelected && !hasFocus ) {
 			// apply inactive selection background/foreground if tree is not focused
 			oldBackgroundSelectionColor = setRendererBackgroundSelectionColor( rendererComponent, selectionInactiveBackground );
 			setRendererForeground( rendererComponent, selectionInactiveForeground );
@@ -625,26 +654,12 @@ public class FlatTreeUI
 		}
 
 		// paint selection background
-		if( needsSelectionPainting ) {
-			// set selection color
-			Color oldColor = g.getColor();
-			g.setColor( isDropRow
-				? UIManager.getColor( "Tree.dropCellBackground" )
-				: (rendererComponent instanceof DefaultTreeCellRenderer
+		if( isSelected && isPaintSelection() ) {
+			Color selectionColor = rendererComponent instanceof DefaultTreeCellRenderer
 				? ((DefaultTreeCellRenderer)rendererComponent).getBackgroundSelectionColor()
-					: (hasFocus ? selectionBackground : selectionInactiveBackground)) );
+				: (hasFocus ? selectionBackground : selectionInactiveBackground);
 
-			if( isWideSelection() ) {
-				// wide selection
-				paintWideSelection( g, bounds, row );
-			} else {
-				// non-wide selection
-				paintCellBackground( g, rendererComponent, bounds, row, true );
-			}
-
-			// this is actually not necessary because renderer should always set color
-			// before painting, but doing anyway to avoid any side effect (in bad renderers)
-			g.setColor( oldColor );
+			paintRowSelection( g, selectionColor, rendererComponent, bounds, row, false );
 		} else {
 			// paint cell background if DefaultTreeCellRenderer.getBackgroundNonSelectionColor() is set
 			if( rendererComponent instanceof DefaultTreeCellRenderer ) {
@@ -653,12 +668,19 @@ public class FlatTreeUI
 				if( bg != null && !bg.equals( defaultCellNonSelectionBackground ) ) {
 					Color oldColor = g.getColor();
 					g.setColor( bg );
-					paintCellBackground( g, rendererComponent, bounds, row, false );
+					paintCellBackground( g, rendererComponent, bounds, row, false, false );
 					g.setColor( oldColor );
 				}
 			}
 		}
 
+		// paint drop background
+		// (this needs to be an extra step for rounded selection)
+		if( isDropRow && isPaintSelection() ) {
+			paintRowSelection( g, UIManager.getColor( "Tree.dropCellBackground" ),
+				rendererComponent, bounds, row, true );
+		}
+
 		// paint renderer
 		rendererPane.paintComponent( g, rendererComponent, tree, bounds.x, bounds.y, bounds.width, bounds.height, true );
 
@@ -669,6 +691,26 @@ public class FlatTreeUI
 			((DefaultTreeCellRenderer)rendererComponent).setBorderSelectionColor( oldBorderSelectionColor );
 	}
 
+	private void paintRowSelection( Graphics g, Color color, Component rendererComponent,
+		Rectangle bounds, int row, boolean paintDropSelection )
+	{
+		// set selection color
+		Color oldColor = g.getColor();
+		g.setColor( color );
+
+		if( isWideSelection() ) {
+			// wide selection
+			paintWideSelection( g, bounds, row, paintDropSelection );
+		} else {
+			// non-wide selection
+			paintCellBackground( g, rendererComponent, bounds, row, true, paintDropSelection );
+		}
+
+		// this is actually not necessary because renderer should always set color
+		// before painting, but doing anyway to avoid any side effect (in bad renderers)
+		g.setColor( oldColor );
+	}
+
 	private Color setRendererBackgroundSelectionColor( Component rendererComponent, Color color ) {
 		Color oldColor = null;
 
@@ -705,11 +747,11 @@ public class FlatTreeUI
 		return oldColor;
 	}
 
-	private void paintWideSelection( Graphics g, Rectangle bounds, int row ) {
+	private void paintWideSelection( Graphics g, Rectangle bounds, int row, boolean paintDropSelection ) {
 		float arcTop, arcBottom;
 		arcTop = arcBottom = UIScale.scale( selectionArc / 2f );
 
-		if( useUnitedRoundedSelection() ) {
+		if( useUnitedRoundedSelection() && !paintDropSelection ) {
 			if( row > 0 && tree.isRowSelected( row - 1 ) )
 				arcTop = 0;
 			if( row < tree.getRowCount() - 1 && tree.isRowSelected( row + 1 ) )
@@ -721,7 +763,7 @@ public class FlatTreeUI
 	}
 
 	private void paintCellBackground( Graphics g, Component rendererComponent, Rectangle bounds,
-		int row, boolean paintSelection )
+		int row, boolean paintSelection, boolean paintDropSelection )
 	{
 		int xOffset = 0;
 		int imageOffset = 0;
@@ -739,7 +781,7 @@ public class FlatTreeUI
 			float arcTopLeft, arcTopRight, arcBottomLeft, arcBottomRight;
 			arcTopLeft = arcTopRight = arcBottomLeft = arcBottomRight = UIScale.scale( selectionArc / 2f );
 
-			if( useUnitedRoundedSelection() ) {
+			if( useUnitedRoundedSelection() && !paintDropSelection ) {
 				if( row > 0 && tree.isRowSelected( row - 1 ) ) {
 					Rectangle r = getPathBounds( tree, tree.getPathForRow( row - 1 ) );
 					arcTopLeft = Math.min( arcTopLeft, r.x - bounds.x );
@@ -794,6 +836,11 @@ public class FlatTreeUI
 		return clientPropertyBoolean( tree, TREE_WIDE_SELECTION, wideSelection );
 	}
 
+	/** @since 3.6 */
+	protected boolean isWideCellRenderer() {
+		return clientPropertyBoolean( tree, TREE_WIDE_CELL_RENDERER, wideCellRenderer );
+	}
+
 	protected boolean isPaintSelection() {
 		return clientPropertyBoolean( tree, TREE_PAINT_SELECTION, paintSelection );
 	}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatUIAction.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2024 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.ui;
+
+import java.beans.PropertyChangeListener;
+import javax.swing.Action;
+
+/**
+ * Base class for UI actions used in ActionMap.
+ * (similar to class sun.swing.UIAction)
+ *
+ * @author Karl Tauber
+ * @since 3.4
+ */
+public abstract class FlatUIAction
+	implements Action
+{
+	protected final String name;
+	protected final Action delegate;
+
+	protected FlatUIAction( String name ) {
+		this.name = name;
+		this.delegate = null;
+	}
+
+	protected FlatUIAction( Action delegate ) {
+		this.name = null;
+		this.delegate = delegate;
+	}
+
+	@Override
+	public Object getValue( String key ) {
+		if( key == NAME && delegate == null )
+			return name;
+		return (delegate != null) ? delegate.getValue( key ) : null;
+	}
+
+	@Override
+	public boolean isEnabled() {
+		return (delegate != null) ? delegate.isEnabled() : true;
+	}
+
+	// do nothing in following methods because this class is immutable
+	@Override public void putValue( String key, Object value ) {}
+	@Override public void setEnabled( boolean b ) {}
+	@Override public void addPropertyChangeListener( PropertyChangeListener listener ) {}
+	@Override public void removePropertyChangeListener( PropertyChangeListener listener ) {}
+}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatUIUtils.java

@@ -26,6 +26,7 @@ import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.GraphicsConfiguration;
 import java.awt.GraphicsDevice;
+import java.awt.GraphicsEnvironment;
 import java.awt.Insets;
 import java.awt.KeyboardFocusManager;
 import java.awt.Paint;
@@ -34,6 +35,7 @@ import java.awt.RenderingHints;
 import java.awt.Shape;
 import java.awt.Stroke;
 import java.awt.SystemColor;
+import java.awt.Toolkit;
 import java.awt.Window;
 import java.awt.event.FocusEvent;
 import java.awt.event.FocusListener;
@@ -60,6 +62,7 @@ import javax.swing.border.Border;
 import javax.swing.border.CompoundBorder;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.UIResource;
+import javax.swing.tree.DefaultTreeCellEditor;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.FlatIntelliJLaf;
 import com.formdev.flatlaf.FlatLaf;
@@ -123,6 +126,25 @@ public class FlatUIUtils
 		dest.right = src.right;
 	}
 
+	/** @since 3.5 */
+	public static boolean isInsetsEmpty( Insets insets ) {
+		return insets.top == 0 && insets.left == 0 && insets.bottom == 0 && insets.right == 0;
+	}
+
+	/** @since 3.6 */
+	public static Color stateColor( boolean state, Color stateColor, Color defaultColor ) {
+		return (state && stateColor != null) ? stateColor : defaultColor;
+	}
+
+	/** @since 3.6 */
+	public static Color stateColor( boolean state1, Color state1Color,
+		boolean state2, Color state2Color, Color defaultColor )
+	{
+		return (state1 && state1Color != null)
+			? state1Color
+			: ((state2 && state2Color != null) ? state2Color : defaultColor);
+	}
+
 	public static Color getUIColor( String key, int defaultColorRGB ) {
 		Color color = UIManager.getColor( key );
 		return (color != null) ? color : new Color( defaultColorRGB );
@@ -299,15 +321,14 @@ public class FlatUIUtils
 		if( c == null )
 			return false;
 
-		// check whether used in cell editor (check 3 levels up)
-		Component c2 = c;
-		for( int i = 0; i <= 2 && c2 != null; i++ ) {
-			Container parent = c2.getParent();
-			if( parent instanceof JTable && ((JTable)parent).getEditorComponent() == c2 )
+		// check whether used as table cell editor
+		Container parent = c.getParent();
+		if( parent instanceof JTable && ((JTable)parent).getEditorComponent() == c )
 			return true;
 
-			c2 = parent;
-		}
+		// check whether used as tree cell editor
+		if( parent instanceof DefaultTreeCellEditor.EditorContainer )
+			return true;
 
 		// check whether used as cell editor
 		//   Table.editor is set in JTable.GenericEditor constructor
@@ -395,6 +416,17 @@ public class FlatUIUtils
 		return (fullScreenWindow != null && fullScreenWindow == SwingUtilities.windowForComponent( c ));
 	}
 
+	/** @since 3.6.1 */
+	public static Insets getScreenInsets( GraphicsConfiguration gc ) {
+		// on Linux, getScreenInsets() may report wrong values in multi-screen setups
+		// see https://github.com/apache/netbeans/issues/8532#issuecomment-2909687016
+		if( SystemInfo.isLinux &&
+			GraphicsEnvironment.getLocalGraphicsEnvironment().getScreenDevices().length > 1 )
+		  return new Insets( 0, 0, 0, 0 );
+
+		return Toolkit.getDefaultToolkit().getScreenInsets( gc );
+	}
+
 	public static Boolean isRoundRect( Component c ) {
 		return (c instanceof JComponent)
 			? FlatClientProperties.clientPropertyBooleanStrict(
@@ -601,28 +633,55 @@ public class FlatUIUtils
 	public static void paintOutlinedComponent( Graphics2D g, int x, int y, int width, int height,
 		float focusWidth, float focusWidthFraction, float focusInnerWidth, float borderWidth, float arc,
 		Paint focusColor, Paint borderColor, Paint background )
+	{
+		paintOutlinedComponent( g, x, y, width, height, focusWidth, focusWidthFraction, focusInnerWidth,
+			borderWidth, arc, focusColor, borderColor, background, false );
+	}
+
+	static void paintOutlinedComponent( Graphics2D g, int x, int y, int width, int height,
+		float focusWidth, float focusWidthFraction, float focusInnerWidth, float borderWidth, float arc,
+		Paint focusColor, Paint borderColor, Paint background, boolean scrollPane )
 	{
 		double systemScaleFactor = UIScale.getSystemScaleFactor( g );
-		if( systemScaleFactor != 1 && systemScaleFactor != 2 ) {
+		if( (int) systemScaleFactor != systemScaleFactor ) {
 			// paint at scale 1x to avoid clipping on right and bottom edges at 125%, 150% or 175%
 			HiDPIUtils.paintAtScale1x( g, x, y, width, height,
 				(g2d, x2, y2, width2, height2, scaleFactor) -> {
 					paintOutlinedComponentImpl( g2d, x2, y2, width2, height2,
 						(float) (focusWidth * scaleFactor), focusWidthFraction, (float) (focusInnerWidth * scaleFactor),
 						(float) (borderWidth * scaleFactor), (float) (arc * scaleFactor),
-						focusColor, borderColor, background );
+						focusColor, borderColor, background, scrollPane, scaleFactor );
 				} );
 			return;
 		}
 
 		paintOutlinedComponentImpl( g, x, y, width, height, focusWidth, focusWidthFraction, focusInnerWidth,
-			borderWidth, arc, focusColor, borderColor, background );
+			borderWidth, arc, focusColor, borderColor, background, scrollPane, systemScaleFactor );
 	}
 
+	@SuppressWarnings( "SelfAssignment" ) // Error Prone
 	private static void paintOutlinedComponentImpl( Graphics2D g, int x, int y, int width, int height,
 		float focusWidth, float focusWidthFraction, float focusInnerWidth, float borderWidth, float arc,
-		Paint focusColor, Paint borderColor, Paint background )
+		Paint focusColor, Paint borderColor, Paint background, boolean scrollPane, double scaleFactor )
 	{
+		// Special handling for scrollpane and fractional scale factors (e.g. 1.25 - 1.75),
+		// where Swing scales one "logical" pixel (border insets) to either one or two physical pixels.
+		// Antialiasing is used to paint the border, which usually needs two physical pixels
+		// at small scale factors. 1px for the solid border and another 1px for antialiasing.
+		// But scrollpane view is painted over the border, which results in a painted border
+		// that is 1px thick at some sides and 2px thick at other sides.
+		if( scrollPane && scaleFactor != (int) scaleFactor ) {
+			if( focusWidth > 0 ) {
+				// reduce outer border thickness (focusWidth) so that inner side of
+				// component border (focusWidth + borderWidth) is at a full pixel
+				int totalWidth = (int) (focusWidth + borderWidth);
+				focusWidth = totalWidth - borderWidth;
+			} else {// if( scaleFactor > 1 && scaleFactor < 2 ) {
+				// reduce component border thickness (borderWidth) to full pixels
+				borderWidth = (int) borderWidth;
+			}
+		}
+
 		// outside bounds of the border and the background
 		float x1 = x + focusWidth;
 		float y1 = y + focusWidth;
@@ -734,7 +793,7 @@ public class FlatUIUtils
 	}
 
 	/**
-	 * Creates a (rounded) rectangle used to paint components (border, background, etc).
+	 * Creates a (rounded) rectangle used to paint components (border, background, etc.).
 	 * The given arc diameter is limited to min(width,height).
 	 */
 	public static Shape createComponentRectangle( float x, float y, float w, float h, float arc ) {
@@ -780,7 +839,7 @@ public class FlatUIUtils
 
 		if( arcTopLeft > 0 || arcTopRight > 0 || arcBottomLeft > 0 || arcBottomRight > 0 ) {
 			double systemScaleFactor = UIScale.getSystemScaleFactor( g );
-			if( systemScaleFactor != 1 && systemScaleFactor != 2 ) {
+			if( systemScaleFactor != (int) systemScaleFactor ) {
 				// paint at scale 1x to avoid clipping on right and bottom edges at 125%, 150% or 175%
 				HiDPIUtils.paintAtScale1x( g, x, y, width, height,
 					(g2d, x2, y2, width2, height2, scaleFactor) -> {
@@ -1315,13 +1374,13 @@ debug*/
 		@Override
 		public void focusGained( FocusEvent e ) {
 			if( repaintCondition == null || repaintCondition.test( repaintComponent ) )
-				repaintComponent.repaint();
+				HiDPIUtils.repaint( repaintComponent );
 		}
 
 		@Override
 		public void focusLost( FocusEvent e ) {
 			if( repaintCondition == null || repaintCondition.test( repaintComponent ) )
-				repaintComponent.repaint();
+				HiDPIUtils.repaint( repaintComponent );
 		}
 	}
 

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatViewportUI.java

@@ -18,7 +18,6 @@ package com.formdev.flatlaf.ui;
 
 import java.awt.Component;
 import java.awt.Graphics;
-import java.lang.reflect.Method;
 import javax.swing.JComponent;
 import javax.swing.JViewport;
 import javax.swing.plaf.ComponentUI;
@@ -48,14 +47,9 @@ public class FlatViewportUI
 
 		Component view = ((JViewport)c).getView();
 		if( view instanceof JComponent ) {
-			try {
-				Method m = view.getClass().getMethod( "getUI" );
-				Object ui = m.invoke( view );
+			ComponentUI ui = JavaCompatibility2.getUI( (JComponent) view );
 			if( ui instanceof ViewportPainter )
 				((ViewportPainter)ui).paintViewport( g, (JComponent) view, (JViewport) c );
-			} catch( Exception ex ) {
-				// ignore
-			}
 		}
 	}
 

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatWindowResizer.java

@@ -41,7 +41,7 @@ import java.util.function.Supplier;
 import javax.swing.DesktopManager;
 import javax.swing.JComponent;
 import javax.swing.JInternalFrame;
-import javax.swing.JLayeredPane;
+import javax.swing.JPanel;
 import javax.swing.JRootPane;
 import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
@@ -59,8 +59,6 @@ import com.formdev.flatlaf.util.UIScale;
 public abstract class FlatWindowResizer
 	implements PropertyChangeListener, ComponentListener
 {
-	protected final static Integer WINDOW_RESIZER_LAYER = JLayeredPane.DRAG_LAYER + 1;
-
 	protected final JComponent resizeComp;
 
 	protected final int borderDragThickness = FlatUIUtils.getUIInt( "RootPane.borderDragThickness", 5 );
@@ -81,12 +79,12 @@ public abstract class FlatWindowResizer
 		leftDragComp = createDragBorderComponent( NW_RESIZE_CURSOR, W_RESIZE_CURSOR, SW_RESIZE_CURSOR );
 		rightDragComp = createDragBorderComponent( NE_RESIZE_CURSOR, E_RESIZE_CURSOR, SE_RESIZE_CURSOR );
 
-		Container cont = (resizeComp instanceof JRootPane) ? ((JRootPane)resizeComp).getLayeredPane() : resizeComp;
-		Object cons = (cont instanceof JLayeredPane) ? WINDOW_RESIZER_LAYER : null;
-		cont.add( topDragComp, cons, 0 );
-		cont.add( bottomDragComp, cons, 1 );
-		cont.add( leftDragComp, cons, 2 );
-		cont.add( rightDragComp, cons, 3 );
+		// for rootpanes, add after glasspane
+		int insertIndex = (resizeComp instanceof JRootPane) ? 1 : 0;
+		resizeComp.add( topDragComp,    insertIndex++ );
+		resizeComp.add( bottomDragComp, insertIndex++ );
+		resizeComp.add( leftDragComp,   insertIndex++ );
+		resizeComp.add( rightDragComp,  insertIndex++ );
 
 		resizeComp.addComponentListener( this );
 		resizeComp.addPropertyChangeListener( "ancestor", this );
@@ -105,11 +103,10 @@ public abstract class FlatWindowResizer
 		resizeComp.removeComponentListener( this );
 		resizeComp.removePropertyChangeListener( "ancestor", this );
 
-		Container cont = topDragComp.getParent();
-		cont.remove( topDragComp );
-		cont.remove( bottomDragComp );
-		cont.remove( leftDragComp );
-		cont.remove( rightDragComp );
+		resizeComp.remove( topDragComp );
+		resizeComp.remove( bottomDragComp );
+		resizeComp.remove( leftDragComp );
+		resizeComp.remove( rightDragComp );
 	}
 
 	public void doLayout() {
@@ -120,7 +117,7 @@ public abstract class FlatWindowResizer
 		int y = 0;
 		int width = resizeComp.getWidth();
 		int height = resizeComp.getHeight();
-		if( width == 0 || height == 0 )
+		if( width <= 0 || height <= 0 )
 			return;
 
 		Insets resizeInsets = getResizeInsets();
@@ -191,7 +188,7 @@ public abstract class FlatWindowResizer
 	protected abstract Dimension getWindowMinimumSize();
 	protected abstract Dimension getWindowMaximumSize();
 
-	protected void beginResizing( int direction ) {}
+	protected void beginResizing( int resizeDir, MouseEvent e ) {}
 	protected void endResizing() {}
 
 	//---- interface PropertyChangeListener ----
@@ -234,17 +231,45 @@ public abstract class FlatWindowResizer
 	{
 		protected Window window;
 
+		private final JComponent centerComp;
 		private final boolean limitResizeToScreenBounds;
 
 		public WindowResizer( JRootPane rootPane ) {
 			super( rootPane );
 
+			// Transparent "center" component that is made visible only while resizing window.
+			// It uses same cursor as the area where resize dragging started.
+			// This ensures that the cursor shape stays stable while dragging mouse
+			// into the window to make window smaller. Otherwise it would toggling between
+			// resize and standard cursor because the component layout is not updated
+			// fast enough and the mouse cursor is always updated from the component
+			// at the mouse location.
+			centerComp = new JPanel();
+			centerComp.setOpaque( false );
+			centerComp.setVisible( false );
+			rootPane.add( centerComp, 5 );
+
 			// On Linux, limit window resizing to screen bounds because otherwise
 			// there would be a strange effect when the mouse is moved over a sidebar
 			// while resizing and the opposite window side is also resized.
 			limitResizeToScreenBounds = SystemInfo.isLinux;
 		}
 
+		@Override
+		public void uninstall() {
+			resizeComp.remove( centerComp );
+
+			super.uninstall();
+		}
+
+		@Override
+		public void doLayout() {
+			super.doLayout();
+
+			if( centerComp != null && centerComp.isVisible() )
+				centerComp.setBounds( 0, 0, resizeComp.getWidth(), resizeComp.getHeight() );
+		}
+
 		@Override
 		protected void addNotify() {
 			Container parent = resizeComp.getParent();
@@ -299,21 +324,18 @@ public abstract class FlatWindowResizer
 
 		@Override
 		protected boolean limitToParentBounds() {
-			return limitResizeToScreenBounds && window != null;
+			return limitResizeToScreenBounds && window != null && window.getGraphicsConfiguration() != null;
 		}
 
 		@Override
 		protected Rectangle getParentBounds() {
-			if( limitResizeToScreenBounds && window != null ) {
 			GraphicsConfiguration gc = window.getGraphicsConfiguration();
 			Rectangle bounds = gc.getBounds();
-				Insets insets = window.getToolkit().getScreenInsets( gc );
+			Insets insets = FlatUIUtils.getScreenInsets( gc );
 			return new Rectangle( bounds.x + insets.left, bounds.y + insets.top,
 				bounds.width - insets.left - insets.right,
 				bounds.height - insets.top - insets.bottom );
 		}
-			return null;
-		}
 
 		@Override
 		protected boolean honorMinimumSizeOnResize() {
@@ -346,6 +368,37 @@ public abstract class FlatWindowResizer
 		public void windowStateChanged( WindowEvent e ) {
 			updateVisibility();
 		}
+
+		@Override
+		protected void beginResizing( int resizeDir, MouseEvent e ) {
+			// on Linux, resize window using window manager
+			if( SystemInfo.isLinux && window != null && FlatNativeLinuxLibrary.isWMUtilsSupported( window ) ) {
+				int direction = -1;
+				switch( resizeDir ) {
+					case N_RESIZE_CURSOR:	direction = FlatNativeLinuxLibrary.SIZE_TOP; break;
+					case S_RESIZE_CURSOR:	direction = FlatNativeLinuxLibrary.SIZE_BOTTOM; break;
+					case W_RESIZE_CURSOR:	direction = FlatNativeLinuxLibrary.SIZE_LEFT; break;
+					case E_RESIZE_CURSOR:	direction = FlatNativeLinuxLibrary.SIZE_RIGHT; break;
+					case NW_RESIZE_CURSOR:	direction = FlatNativeLinuxLibrary.SIZE_TOPLEFT; break;
+					case NE_RESIZE_CURSOR:	direction = FlatNativeLinuxLibrary.SIZE_TOPRIGHT; break;
+					case SW_RESIZE_CURSOR:	direction = FlatNativeLinuxLibrary.SIZE_BOTTOMLEFT; break;
+					case SE_RESIZE_CURSOR:	direction = FlatNativeLinuxLibrary.SIZE_BOTTOMRIGHT; break;
+				}
+
+				if( direction >= 0 && FlatNativeLinuxLibrary.moveOrResizeWindow( window, e, direction ) )
+					return;
+			}
+
+			centerComp.setBounds( 0, 0, resizeComp.getWidth(), resizeComp.getHeight() );
+			centerComp.setCursor( getPredefinedCursor( resizeDir ) );
+			centerComp.setVisible( true );
+		}
+
+		@Override
+		protected void endResizing() {
+			centerComp.setVisible( false );
+			centerComp.setCursor( null );
+		}
 	}
 
 	//---- class InternalFrameResizer -----------------------------------------
@@ -427,7 +480,18 @@ public abstract class FlatWindowResizer
 		}
 
 		@Override
-		protected void beginResizing( int direction ) {
+		protected void beginResizing( int resizeDir, MouseEvent e ) {
+			int direction = 0;
+			switch( resizeDir ) {
+				case N_RESIZE_CURSOR:	direction = NORTH; break;
+				case S_RESIZE_CURSOR:	direction = SOUTH; break;
+				case W_RESIZE_CURSOR:	direction = WEST; break;
+				case E_RESIZE_CURSOR:	direction = EAST; break;
+				case NW_RESIZE_CURSOR:	direction = NORTH_WEST; break;
+				case NE_RESIZE_CURSOR:	direction = NORTH_EAST; break;
+				case SW_RESIZE_CURSOR:	direction = SOUTH_WEST; break;
+				case SE_RESIZE_CURSOR:	direction = SOUTH_EAST; break;
+			}
 			desktopManager.get().beginResizingFrame( getFrame(), direction );
 		}
 
@@ -535,18 +599,7 @@ debug*/
 			dragRightOffset = windowBounds.x + windowBounds.width - xOnScreen;
 			dragBottomOffset = windowBounds.y + windowBounds.height - yOnScreen;
 
-			int direction = 0;
-			switch( resizeDir ) {
-				case N_RESIZE_CURSOR:	direction = NORTH; break;
-				case S_RESIZE_CURSOR:	direction = SOUTH; break;
-				case W_RESIZE_CURSOR:	direction = WEST; break;
-				case E_RESIZE_CURSOR:	direction = EAST; break;
-				case NW_RESIZE_CURSOR:	direction = NORTH_WEST; break;
-				case NE_RESIZE_CURSOR:	direction = NORTH_EAST; break;
-				case SW_RESIZE_CURSOR:	direction = SOUTH_WEST; break;
-				case SE_RESIZE_CURSOR:	direction = SOUTH_EAST; break;
-			}
-			beginResizing( direction );
+			beginResizing( resizeDir, e );
 		}
 
 		@Override

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatWindowsNativeWindowBorder.java

@@ -21,6 +21,7 @@ import java.awt.Dialog;
 import java.awt.EventQueue;
 import java.awt.Frame;
 import java.awt.GraphicsConfiguration;
+import java.awt.Insets;
 import java.awt.Point;
 import java.awt.Rectangle;
 import java.awt.Window;
@@ -29,8 +30,8 @@ import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
 import java.util.Collections;
 import java.util.IdentityHashMap;
-import java.util.List;
 import java.util.Map;
+import java.util.function.Predicate;
 import javax.swing.JDialog;
 import javax.swing.JFrame;
 import javax.swing.Timer;
@@ -39,6 +40,7 @@ import javax.swing.event.ChangeListener;
 import javax.swing.event.EventListenerList;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.SystemInfo;
+import com.formdev.flatlaf.util.UIScale;
 
 //
 // Interesting resources:
@@ -89,7 +91,7 @@ class FlatWindowsNativeWindowBorder
 			return null;
 
 		// check whether native library was successfully loaded
-		if( !FlatNativeLibrary.isLoaded() )
+		if( !FlatNativeWindowsLibrary.isLoaded() )
 			return null;
 
 		// create new instance
@@ -159,7 +161,7 @@ class FlatWindowsNativeWindowBorder
 	}
 
 	@Override
-	public void updateTitleBarInfo( Window window, int titleBarHeight, List<Rectangle> hitTestSpots,
+	public void updateTitleBarInfo( Window window, int titleBarHeight, Predicate<Point> captionHitTestCallback,
 		Rectangle appIconBounds, Rectangle minimizeButtonBounds, Rectangle maximizeButtonBounds,
 		Rectangle closeButtonBounds )
 	{
@@ -168,7 +170,7 @@ class FlatWindowsNativeWindowBorder
 			return;
 
 		wndProc.titleBarHeight = titleBarHeight;
-		wndProc.hitTestSpots = hitTestSpots.toArray( new Rectangle[hitTestSpots.size()] );
+		wndProc.captionHitTestCallback = captionHitTestCallback;
 		wndProc.appIconBounds = cloneRectange( appIconBounds );
 		wndProc.minimizeButtonBounds = cloneRectange( minimizeButtonBounds );
 		wndProc.maximizeButtonBounds = cloneRectange( maximizeButtonBounds );
@@ -282,14 +284,16 @@ class FlatWindowsNativeWindowBorder
 			HTMINBUTTON = 8,
 			HTMAXBUTTON = 9,
 			HTTOP = 12,
+			HTTOPLEFT = 13,
+			HTTOPRIGHT = 14,
 			HTCLOSE = 20;
 
 		private Window window;
 		private final long hwnd;
 
 		// Swing coordinates/values may be scaled on a HiDPI screen
-		private int titleBarHeight;
-		private Rectangle[] hitTestSpots;
+		private int titleBarHeight; // measured from window top edge, which may be out-of-screen if maximized
+		private Predicate<Point> captionHitTestCallback;
 		private Rectangle appIconBounds;
 		private Rectangle minimizeButtonBounds;
 		private Rectangle maximizeButtonBounds;
@@ -340,50 +344,80 @@ class FlatWindowsNativeWindowBorder
 		private int onNcHitTest( int x, int y, boolean isOnResizeBorder ) {
 			// scale-down mouse x/y because Swing coordinates/values may be scaled on a HiDPI screen
 			Point pt = scaleDown( x, y );
-			int sx = pt.x;
-			int sy = pt.y;
+
+			// limit top resize border to 4px, which seems to be standard for modern WinUI apps
+			if( isOnResizeBorder && pt.y > UIScale.scale( 4 ) )
+				isOnResizeBorder = false;
+
+			if( isOnResizeBorder ) {
+				Insets insets = window.getInsets();
+
+				// return HTTOPLEFT if mouse is over top resize border on left side
+				//   - hovering mouse shows top-left resize cursor
+				//   - left-click-and-drag resizes window
+				if( pt.x <= insets.left + UIScale.scale( 12 ) )
+					return HTTOPLEFT;
+
+				// return HTTOPRIGHT if mouse is over top resize border on right side
+				//   - hovering mouse shows top-right resize cursor
+				//   - left-click-and-drag resizes window
+				if( pt.x >= window.getWidth() - insets.right - UIScale.scale( 12 ) )
+					return HTTOPRIGHT;
+
+				// return HTTOP if mouse is over top resize border
+				//   - hovering mouse shows vertical resize cursor
+				//   - left-click-and-drag vertically resizes window
+				return HTTOP;
+			}
 
 			// return HTSYSMENU if mouse is over application icon
 			//   - left-click on HTSYSMENU area shows system menu
 			//   - double-left-click sends WM_CLOSE
-			if( contains( appIconBounds, sx, sy ) )
+			if( contains( appIconBounds, pt ) )
 				return HTSYSMENU;
 
 			// return HTMINBUTTON if mouse is over minimize button
 			//   - hovering mouse over HTMINBUTTON area shows tooltip on Windows 10/11
-			if( contains( minimizeButtonBounds, sx, sy ) )
+			if( contains( minimizeButtonBounds, pt ) )
 				return HTMINBUTTON;
 
 			// return HTMAXBUTTON if mouse is over maximize/restore button
 			//   - hovering mouse over HTMAXBUTTON area shows tooltip on Windows 10
 			//   - hovering mouse over HTMAXBUTTON area shows snap layouts menu on Windows 11
 			//     https://docs.microsoft.com/en-us/windows/apps/desktop/modernize/apply-snap-layout-menu
-			if( contains( maximizeButtonBounds, sx, sy ) )
+			if( contains( maximizeButtonBounds, pt ) )
 				return HTMAXBUTTON;
 
 			// return HTCLOSE if mouse is over close button
 			//   - hovering mouse over HTCLOSE area shows tooltip on Windows 10/11
-			if( contains( closeButtonBounds, sx, sy ) )
+			if( contains( closeButtonBounds, pt ) )
 				return HTCLOSE;
 
-			boolean isOnTitleBar = (sy < titleBarHeight);
-
+			boolean isOnTitleBar = (pt.y < titleBarHeight);
 			if( isOnTitleBar ) {
-				// use a second reference to the array to avoid that it can be changed
-				// in another thread while processing the array
-				Rectangle[] hitTestSpots2 = hitTestSpots;
-				for( Rectangle spot : hitTestSpots2 ) {
-					if( spot.contains( sx, sy ) )
+				// return HTCLIENT if mouse is over any Swing component in title bar
+				// that processes mouse events (e.g. buttons, menus, etc)
+				//   - Windows ignores mouse events in this area
+				try {
+					if( captionHitTestCallback != null && !captionHitTestCallback.test( pt ) )
+						return HTCLIENT;
+				} catch( Throwable ex ) {
+					// ignore
+				}
+
+				// return HTCAPTION if mouse is over title bar
+				//   - right-click shows system menu
+				//   - double-left-click maximizes/restores window size
+				return HTCAPTION;
+			}
+
+			// return HTCLIENT
+			//   - Windows ignores mouse events in this area
 			return HTCLIENT;
 		}
-				return isOnResizeBorder ? HTTOP : HTCAPTION;
-			}
 
-			return isOnResizeBorder ? HTTOP : HTCLIENT;
-		}
-
-		private boolean contains( Rectangle rect, int x, int y ) {
-			return (rect != null && rect.contains( x, y ) );
+		private boolean contains( Rectangle rect, Point pt ) {
+			return (rect != null && rect.contains( pt ) );
 		}
 
 		/**

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FullWindowContentSupport.java

@@ -0,0 +1,219 @@
+/*
+ * Copyright 2024 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.ui;
+
+import java.awt.Color;
+import java.awt.Component;
+import java.awt.Dimension;
+import java.awt.Graphics;
+import java.awt.Rectangle;
+import java.awt.Window;
+import java.awt.event.ComponentAdapter;
+import java.awt.event.ComponentEvent;
+import java.awt.event.ComponentListener;
+import java.lang.ref.WeakReference;
+import java.util.ArrayList;
+import java.util.Iterator;
+import javax.swing.JComponent;
+import javax.swing.JRootPane;
+import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
+import com.formdev.flatlaf.FlatClientProperties;
+import com.formdev.flatlaf.util.SystemInfo;
+
+/**
+ * @author Karl Tauber
+ */
+class FullWindowContentSupport
+{
+	private static final String KEY_DEBUG_SHOW_PLACEHOLDERS = "FlatLaf.debug.panel.showPlaceholders";
+
+	private static ArrayList<WeakReference<JComponent>> placeholders = new ArrayList<>();
+
+	static Dimension getPlaceholderPreferredSize( JComponent c, String options ) {
+		JRootPane rootPane;
+		Rectangle bounds;
+
+		if( !options.startsWith( SystemInfo.isMacOS ? "mac" : "win" ) ||
+			!c.isDisplayable() ||
+			(rootPane = SwingUtilities.getRootPane( c )) == null ||
+			(bounds = (Rectangle) rootPane.getClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_BOUNDS )) == null )
+		  return new Dimension( 0, 0 );
+
+		if( options.length() > 3 ) {
+			if( (options.contains( "leftToRight" ) && !c.getComponentOrientation().isLeftToRight()) ||
+				(options.contains( "rightToLeft" ) && c.getComponentOrientation().isLeftToRight()) )
+			  return new Dimension( 0, 0 );
+		}
+
+		// On macOS, the client property is updated very late when toggling full screen,
+		// which results in "jumping" layout after full screen toggle finished.
+		// To avoid that, get up-to-date buttons bounds from macOS.
+		if( SystemInfo.isMacFullWindowContentSupported && FlatNativeMacLibrary.isLoaded() ) {
+			Rectangle r = FlatNativeMacLibrary.getWindowButtonsBounds( SwingUtilities.windowForComponent( c ) );
+			if( r != null )
+				bounds = r;
+		}
+
+		int width = bounds.width;
+		int height = bounds.height;
+
+		if( options.length() > 3 ) {
+			if( width == 0 && options.contains( "zeroInFullScreen" ) )
+				height = 0;
+
+			if( options.contains( "horizontal" ) )
+				height = 0;
+			if( options.contains( "vertical" ) )
+				width = 0;
+		}
+
+		return new Dimension( width, height );
+	}
+
+	static void registerPlaceholder( JComponent c ) {
+		synchronized( placeholders ) {
+			if( indexOfPlaceholder( c ) < 0 )
+				placeholders.add( new WeakReference<>( c ) );
+		}
+	}
+
+	static void unregisterPlaceholder( JComponent c ) {
+		synchronized( placeholders ) {
+			int index = indexOfPlaceholder( c );
+			if( index >= 0 )
+				placeholders.remove( index );
+		}
+	}
+
+	private static int indexOfPlaceholder( JComponent c ) {
+		int size = placeholders.size();
+		for( int i = 0; i < size; i++ ) {
+			if( placeholders.get( i ).get() == c )
+				return i;
+		}
+		return -1;
+	}
+
+	static void revalidatePlaceholders( Component container ) {
+		synchronized( placeholders ) {
+			if( placeholders.isEmpty() )
+				return;
+
+			for( Iterator<WeakReference<JComponent>> it = placeholders.iterator(); it.hasNext(); ) {
+				WeakReference<JComponent> ref = it.next();
+				JComponent c = ref.get();
+
+				// remove already released placeholder
+				if( c == null ) {
+					it.remove();
+					continue;
+				}
+
+				// revalidate placeholder if is in given container
+				if( SwingUtilities.isDescendingFrom( c, container ) )
+					c.revalidate();
+			}
+		}
+	}
+
+	static ComponentListener macInstallListeners( JRootPane rootPane ) {
+		ComponentListener l = new ComponentAdapter() {
+			boolean lastFullScreen;
+
+			@Override
+			public void componentResized( ComponentEvent e ) {
+				Window window = SwingUtilities.windowForComponent( rootPane );
+				if( window == null )
+					return;
+
+				boolean fullScreen = FlatNativeMacLibrary.isLoaded() && FlatNativeMacLibrary.isWindowFullScreen( window );
+				if( fullScreen == lastFullScreen )
+					return;
+
+				lastFullScreen = fullScreen;
+				macUpdateFullWindowContentButtonsBoundsProperty( rootPane );
+			}
+		};
+
+		rootPane.addComponentListener( l );
+		return l;
+	}
+
+	static void macUninstallListeners( JRootPane rootPane, ComponentListener l ) {
+		if( l != null )
+			rootPane.removeComponentListener( l );
+	}
+
+	static void macUpdateFullWindowContentButtonsBoundsProperty( JRootPane rootPane ) {
+		if( !SystemInfo.isMacFullWindowContentSupported || !rootPane.isDisplayable() )
+			return;
+
+		Rectangle bounds = null;
+		if( FlatClientProperties.clientPropertyBoolean( rootPane, "apple.awt.fullWindowContent", false ) ) {
+			bounds = FlatNativeMacLibrary.isLoaded()
+				? FlatNativeMacLibrary.getWindowButtonsBounds( SwingUtilities.windowForComponent( rootPane ) )
+				: new Rectangle( 68, 28 ); // default size
+		}
+		rootPane.putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_BOUNDS, bounds );
+	}
+
+	static void macUninstallFullWindowContentButtonsBoundsProperty( JRootPane rootPane ) {
+		if( !SystemInfo.isMacFullWindowContentSupported )
+			return;
+
+		rootPane.putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_BOUNDS, null );
+	}
+
+	static void debugPaint( Graphics g, JComponent c ) {
+		if( !UIManager.getBoolean( KEY_DEBUG_SHOW_PLACEHOLDERS ) )
+			return;
+
+		int width = c.getWidth();
+		int height = c.getHeight();
+		if( width <= 0 || height <= 0 )
+			return;
+
+		// draw red figure
+		g.setColor( Color.red );
+		debugPaintRect( g, new Rectangle( width, height ) );
+
+		// draw magenta figure if buttons bounds are not equal to placeholder bounds
+		JRootPane rootPane;
+		Rectangle bounds;
+		if( (rootPane = SwingUtilities.getRootPane( c )) != null &&
+			(bounds = (Rectangle) rootPane.getClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_BOUNDS )) != null &&
+			(bounds.width != width || bounds.height != height) )
+		{
+			g.setColor( Color.magenta );
+			debugPaintRect( g, SwingUtilities.convertRectangle( rootPane, bounds, c ) );
+		}
+	}
+
+	private static void debugPaintRect( Graphics g, Rectangle r ) {
+		// draw rectangle
+		g.drawRect( r.x, r.y, r.width - 1, r.height - 1 );
+
+		// draw diagonal cross
+		int x2 = r.x + r.width - 1;
+		int y2 = r.y + r.height - 1;
+		Object[] oldRenderingHints = FlatUIUtils.setRenderingHints( g );
+		g.drawLine( r.x, r.y, x2, y2 );
+		g.drawLine( r.x, y2, x2, r.y );
+		FlatUIUtils.resetRenderingHints( g, oldRenderingHints );
+	}
+}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/JBRCustomDecorations.java

@@ -1,306 +0,0 @@
-/*
- * Copyright 2020 FormDev Software GmbH
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.formdev.flatlaf.ui;
-
-import java.awt.Color;
-import java.awt.Component;
-import java.awt.Container;
-import java.awt.EventQueue;
-import java.awt.Graphics;
-import java.awt.Graphics2D;
-import java.awt.Rectangle;
-import java.awt.Toolkit;
-import java.awt.Window;
-import java.awt.event.HierarchyEvent;
-import java.awt.event.HierarchyListener;
-import java.beans.PropertyChangeListener;
-import java.lang.reflect.Method;
-import java.util.Collections;
-import java.util.List;
-import javax.swing.JRootPane;
-import javax.swing.SwingUtilities;
-import javax.swing.UIManager;
-import javax.swing.plaf.BorderUIResource;
-import com.formdev.flatlaf.FlatLaf;
-import com.formdev.flatlaf.util.LoggingFacade;
-import com.formdev.flatlaf.util.HiDPIUtils;
-import com.formdev.flatlaf.util.SystemInfo;
-
-/**
- * Support for custom window decorations provided by JetBrains Runtime (based on OpenJDK).
- * Requires that the application runs on Windows 10 in a JetBrains Runtime 11 or later.
- * <ul>
- *   <li><a href="https://confluence.jetbrains.com/display/JBR/JetBrains+Runtime">https://confluence.jetbrains.com/display/JBR/JetBrains+Runtime</a></li>
- *   <li><a href="https://github.com/JetBrains/JetBrainsRuntime">https://github.com/JetBrains/JetBrainsRuntime</a></li>
- * </ul>
- *
- * @author Karl Tauber
- */
-public class JBRCustomDecorations
-{
-	private static Boolean supported;
-	private static Method Window_hasCustomDecoration;
-	private static Method Window_setHasCustomDecoration;
-	private static Method WWindowPeer_setCustomDecorationTitleBarHeight;
-	private static Method WWindowPeer_setCustomDecorationHitTestSpots;
-	private static Method AWTAccessor_getComponentAccessor;
-	private static Method AWTAccessor_ComponentAccessor_getPeer;
-
-	public static boolean isSupported() {
-		initialize();
-		return supported;
-	}
-
-	static Object install( JRootPane rootPane ) {
-		if( !isSupported() )
-			return null;
-
-		// check whether root pane already has a parent, which is the case when switching LaF
-		Container parent = rootPane.getParent();
-		if( parent != null ) {
-			if( parent instanceof Window )
-				FlatNativeWindowBorder.install( (Window) parent );
-			return null;
-		}
-
-		// Use hierarchy listener to wait until the root pane is added to a window.
-		// Enabling JBR decorations must be done very early, probably before
-		// window becomes displayable (window.isDisplayable()). Tried also using
-		// "ancestor" property change event on root pane, but this is invoked too late.
-		HierarchyListener addListener = new HierarchyListener() {
-			@Override
-			public void hierarchyChanged( HierarchyEvent e ) {
-				if( e.getChanged() != rootPane || (e.getChangeFlags() & HierarchyEvent.PARENT_CHANGED) == 0 )
-					return;
-
-				Container parent = e.getChangedParent();
-				if( parent instanceof Window )
-					FlatNativeWindowBorder.install( (Window) parent );
-
-				// remove listener since it is actually not possible to uninstall JBR decorations
-				// use invokeLater to remove listener to avoid that listener
-				// is removed while listener queue is processed
-				EventQueue.invokeLater( () -> {
-					rootPane.removeHierarchyListener( this );
-				} );
-			}
-		};
-		rootPane.addHierarchyListener( addListener );
-		return addListener;
-	}
-
-	static void uninstall( JRootPane rootPane, Object data ) {
-		// remove listener (if not yet done)
-		if( data instanceof HierarchyListener )
-			rootPane.removeHierarchyListener( (HierarchyListener) data );
-
-		// since it is actually not possible to uninstall JBR decorations,
-		// simply reduce titleBarHeight so that it is still possible to resize window
-		// and remove hitTestSpots
-		Container parent = rootPane.getParent();
-		if( parent instanceof Window )
-			setHasCustomDecoration( (Window) parent, false );
-	}
-
-	static boolean hasCustomDecoration( Window window ) {
-		if( !isSupported() )
-			return false;
-
-		try {
-			return (Boolean) Window_hasCustomDecoration.invoke( window );
-		} catch( Exception ex ) {
-			LoggingFacade.INSTANCE.logSevere( null, ex );
-			return false;
-		}
-	}
-
-	static void setHasCustomDecoration( Window window, boolean hasCustomDecoration ) {
-		if( !isSupported() )
-			return;
-
-		try {
-			if( hasCustomDecoration )
-				Window_setHasCustomDecoration.invoke( window );
-			else
-				setTitleBarHeightAndHitTestSpots( window, 4, Collections.emptyList() );
-		} catch( Exception ex ) {
-			LoggingFacade.INSTANCE.logSevere( null, ex );
-		}
-	}
-
-	static void setTitleBarHeightAndHitTestSpots( Window window, int titleBarHeight, List<Rectangle> hitTestSpots ) {
-		if( !isSupported() )
-			return;
-
-		try {
-			Object compAccessor = AWTAccessor_getComponentAccessor.invoke( null );
-			Object peer = AWTAccessor_ComponentAccessor_getPeer.invoke( compAccessor, window );
-			WWindowPeer_setCustomDecorationTitleBarHeight.invoke( peer, titleBarHeight );
-			WWindowPeer_setCustomDecorationHitTestSpots.invoke( peer, hitTestSpots );
-		} catch( Exception ex ) {
-			LoggingFacade.INSTANCE.logSevere( null, ex );
-		}
-	}
-
-	private static void initialize() {
-		if( supported != null )
-			return;
-		supported = false;
-
-		// requires JetBrains Runtime 11 and Windows 10
-		if( !SystemInfo.isJetBrainsJVM_11_orLater || !SystemInfo.isWindows_10_orLater )
-			return;
-
-		try {
-			Class<?> awtAcessorClass = Class.forName( "sun.awt.AWTAccessor" );
-			Class<?> compAccessorClass = Class.forName( "sun.awt.AWTAccessor$ComponentAccessor" );
-			AWTAccessor_getComponentAccessor = awtAcessorClass.getDeclaredMethod( "getComponentAccessor" );
-			AWTAccessor_ComponentAccessor_getPeer = compAccessorClass.getDeclaredMethod( "getPeer", Component.class );
-
-			Class<?> peerClass = Class.forName( "sun.awt.windows.WWindowPeer" );
-			WWindowPeer_setCustomDecorationTitleBarHeight = peerClass.getDeclaredMethod( "setCustomDecorationTitleBarHeight", int.class );
-			WWindowPeer_setCustomDecorationHitTestSpots = peerClass.getDeclaredMethod( "setCustomDecorationHitTestSpots", List.class );
-			WWindowPeer_setCustomDecorationTitleBarHeight.setAccessible( true );
-			WWindowPeer_setCustomDecorationHitTestSpots.setAccessible( true );
-
-			Window_hasCustomDecoration = Window.class.getDeclaredMethod( "hasCustomDecoration" );
-			Window_setHasCustomDecoration = Window.class.getDeclaredMethod( "setHasCustomDecoration" );
-			Window_hasCustomDecoration.setAccessible( true );
-			Window_setHasCustomDecoration.setAccessible( true );
-
-			supported = true;
-		} catch( Exception ex ) {
-			// ignore
-		}
-	}
-
-	//---- class JBRWindowTopBorder -------------------------------------------
-
-	static class JBRWindowTopBorder
-		extends BorderUIResource.EmptyBorderUIResource
-	{
-		private static JBRWindowTopBorder instance;
-
-		private final Color activeLightColor = new Color( 0x707070 );
-		private final Color activeDarkColor = new Color( 0x2D2E2F );
-		private final Color inactiveLightColor = new Color( 0xaaaaaa );
-		private final Color inactiveDarkColor = new Color( 0x494A4B );
-
-		private boolean colorizationAffectsBorders;
-		private Color activeColor;
-
-		static JBRWindowTopBorder getInstance() {
-			if( instance == null )
-				instance = new JBRWindowTopBorder();
-			return instance;
-		}
-
-        JBRWindowTopBorder() {
-			super( 1, 0, 0, 0 );
-
-			update();
-			installListeners();
-        }
-
-        void update() {
-			colorizationAffectsBorders = isColorizationColorAffectsBorders();
-			activeColor = calculateActiveBorderColor();
-        }
-
-        void installListeners() {
-			Toolkit toolkit = Toolkit.getDefaultToolkit();
-			toolkit.addPropertyChangeListener( "win.dwm.colorizationColor.affects.borders", e -> {
-				colorizationAffectsBorders = isColorizationColorAffectsBorders();
-				activeColor = calculateActiveBorderColor();
-			} );
-
-			PropertyChangeListener l = e -> {
-				activeColor = calculateActiveBorderColor();
-			};
-			toolkit.addPropertyChangeListener( "win.dwm.colorizationColor", l );
-			toolkit.addPropertyChangeListener( "win.dwm.colorizationColorBalance", l );
-			toolkit.addPropertyChangeListener( "win.frame.activeBorderColor", l );
-		}
-
-        boolean isColorizationColorAffectsBorders() {
-			Object value = Toolkit.getDefaultToolkit().getDesktopProperty( "win.dwm.colorizationColor.affects.borders" );
-			return (value instanceof Boolean) ? (Boolean) value : true;
-		}
-
-        Color getColorizationColor() {
-			return (Color) Toolkit.getDefaultToolkit().getDesktopProperty( "win.dwm.colorizationColor" );
-        }
-
-        int getColorizationColorBalance() {
-			Object value = Toolkit.getDefaultToolkit().getDesktopProperty( "win.dwm.colorizationColorBalance" );
-			return (value instanceof Integer) ? (Integer) value : -1;
-        }
-
-		private Color calculateActiveBorderColor() {
-			if( !colorizationAffectsBorders )
-				return null;
-
-			Color colorizationColor = getColorizationColor();
-			if( colorizationColor != null ) {
-				int colorizationColorBalance = getColorizationColorBalance();
-				if( colorizationColorBalance < 0 || colorizationColorBalance > 100 )
-					colorizationColorBalance = 100;
-
-				if( colorizationColorBalance == 0 )
-					return new Color( 0xD9D9D9 );
-				if( colorizationColorBalance == 100 )
-					return colorizationColor;
-
-				float alpha = colorizationColorBalance / 100.0f;
-				float remainder = 1 - alpha;
-				int r = Math.round( colorizationColor.getRed() * alpha + 0xD9 * remainder );
-				int g = Math.round( colorizationColor.getGreen() * alpha + 0xD9 * remainder );
-				int b = Math.round( colorizationColor.getBlue() * alpha + 0xD9 * remainder );
-
-				// avoid potential IllegalArgumentException in Color constructor
-				r = Math.min( Math.max( r, 0 ), 255 );
-				g = Math.min( Math.max( g, 0 ), 255 );
-				b = Math.min( Math.max( b, 0 ), 255 );
-
-				return new Color( r, g, b );
-			}
-
-			Color activeBorderColor = (Color) Toolkit.getDefaultToolkit().getDesktopProperty( "win.frame.activeBorderColor" );
-			return (activeBorderColor != null) ? activeBorderColor : UIManager.getColor( "MenuBar.borderColor" );
-		}
-
-		@Override
-		public void paintBorder( Component c, Graphics g, int x, int y, int width, int height ) {
-			Window window = SwingUtilities.windowForComponent( c );
-			boolean active = window != null && window.isActive();
-			boolean dark = FlatLaf.isLafDark();
-
-			g.setColor( active
-				? (activeColor != null ? activeColor : (dark ? activeDarkColor : activeLightColor))
-				: (dark ? inactiveDarkColor : inactiveLightColor) );
-			HiDPIUtils.paintAtScale1x( (Graphics2D) g, x, y, width, height, this::paintImpl );
-		}
-
-		private void paintImpl( Graphics2D g, int x, int y, int width, int height, double scaleFactor ) {
-			g.fillRect( x, y, width, 1 );
-		}
-
-		void repaintBorder( Component c ) {
-			c.repaint( 0, 0, c.getWidth(), 1 );
-		}
-	}
-}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/JavaCompatibility2.java

@@ -0,0 +1,153 @@
+/*
+ * Copyright 2024 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.ui;
+
+import java.io.File;
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodType;
+import java.lang.reflect.Method;
+import javax.swing.JComponent;
+import javax.swing.JList;
+import javax.swing.JPanel;
+import javax.swing.JTable;
+import javax.swing.JTree;
+import javax.swing.filechooser.FileSystemView;
+import javax.swing.plaf.ComponentUI;
+import javax.swing.text.JTextComponent;
+import com.formdev.flatlaf.util.LoggingFacade;
+import com.formdev.flatlaf.util.SystemInfo;
+
+/**
+ * Provides Java version compatibility methods.
+ * <p>
+ * WARNING: This is private API and may change.
+ *
+ * @author Karl Tauber
+ * @since 3.3
+ */
+public class JavaCompatibility2
+{
+	private static boolean getUIMethodInitialized;
+	private static MethodHandle getUIMethod;
+
+	/**
+	 * Java 8: getUI() method on various components (e.g. JButton, JList, etc)
+	 * <br>
+	 * Java 9: javax.swing.JComponent.getUI()
+	 */
+	public static ComponentUI getUI( JComponent c ) {
+		try {
+			// Java 9+
+			if( SystemInfo.isJava_9_orLater ) {
+				if( !getUIMethodInitialized ) {
+					getUIMethodInitialized = true;
+
+					try {
+						MethodType mt = MethodType.methodType( ComponentUI.class, new Class[0] );
+						getUIMethod = MethodHandles.publicLookup().findVirtual( JComponent.class, "getUI", mt );
+					} catch( Exception ex ) {
+						// ignore
+						LoggingFacade.INSTANCE.logSevere( null, ex );
+					}
+				}
+
+				if( getUIMethod != null )
+					return (ComponentUI) getUIMethod.invoke( c );
+			}
+
+			// components often used (e.g. as view in scroll panes)
+			if( c instanceof JPanel )
+				return ((JPanel)c).getUI();
+			if( c instanceof JList )
+				return ((JList<?>)c).getUI();
+			if( c instanceof JTable )
+				return ((JTable)c).getUI();
+			if( c instanceof JTree )
+				return ((JTree)c).getUI();
+			if( c instanceof JTextComponent )
+				return ((JTextComponent)c).getUI();
+
+			// Java 8 and fallback
+			Method m = c.getClass().getMethod( "getUI" );
+			return (ComponentUI) m.invoke( c );
+		} catch( Throwable ex ) {
+			// ignore
+			return null;
+		}
+	}
+
+	/**
+	 * Java 8 - 11 on Windows: sun.awt.shell.ShellFolder.get( "fileChooserShortcutPanelFolders" )
+	 * <br>
+	 * Java 12: javax.swing.filechooser.FileSystemView.getChooserShortcutPanelFiles()
+	 *
+	 * @since 3.4
+	 */
+	public static File[] getChooserShortcutPanelFiles( FileSystemView fsv ) {
+		try {
+			if( SystemInfo.isJava_12_orLater ) {
+				Method m = fsv.getClass().getMethod( "getChooserShortcutPanelFiles" );
+				File[] files = (File[]) m.invoke( fsv );
+
+				// on macOS and Linux, files consists only of the user home directory
+				if( files.length == 1 && files[0].equals( new File( System.getProperty( "user.home" ) ) ) )
+					files = new File[0];
+
+				return files;
+			} else if( SystemInfo.isWindows ) {
+				Class<?> cls = Class.forName( "sun.awt.shell.ShellFolder" );
+				Method m = cls.getMethod( "get", String.class );
+				return (File[]) m.invoke( null, "fileChooserShortcutPanelFolders" );
+			}
+		} catch( IllegalAccessException ex ) {
+			// do not log because access may be denied via VM option '--illegal-access=deny'
+		} catch( Exception ex ) {
+			LoggingFacade.INSTANCE.logSevere( null, ex );
+		}
+
+		// fallback
+		return new File[0];
+	}
+
+	/**
+	 * Java 8: sun.awt.shell.ShellFolder.get( "fileChooserComboBoxFolders" )
+	 * <br>
+	 * Java 9: javax.swing.filechooser.FileSystemView.getChooserComboBoxFiles()
+	 *
+	 * @since 3.4
+	 */
+	public static File[] getChooserComboBoxFiles( FileSystemView fsv ) {
+		try {
+			if( SystemInfo.isJava_9_orLater ) {
+				Method m = fsv.getClass().getMethod( "getChooserComboBoxFiles" );
+				return (File[]) m.invoke( fsv );
+			} else {
+				Class<?> cls = Class.forName( "sun.awt.shell.ShellFolder" );
+				Method m = cls.getMethod( "get", String.class );
+				return (File[]) m.invoke( null, "fileChooserComboBoxFolders" );
+			}
+		} catch( IllegalAccessException ex ) {
+			// do not log because access may be denied via VM option '--illegal-access=deny'
+		} catch( Exception ex ) {
+			LoggingFacade.INSTANCE.logSevere( null, ex );
+		}
+
+		// fallback
+		return new File[0];
+	}
+}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/StackUtils.java

@@ -21,7 +21,7 @@ import java.util.function.BiPredicate;
 /**
  * @author Karl Tauber
  */
-class StackUtils
+public class StackUtils
 {
 	private static final StackUtils INSTANCE = new StackUtilsImpl();
 

flatlaf-core/src/main/java/com/formdev/flatlaf/util/ColorFunctions.java

@@ -224,6 +224,9 @@ public class ColorFunctions
 		if( functions.length == 1 && functions[0] instanceof Mix ) {
 			Mix mixFunction = (Mix) functions[0];
 			return mix( color, mixFunction.color2, mixFunction.weight / 100 );
+		} else if( functions.length == 1 && functions[0] instanceof Mix2 ) {
+			Mix2 mixFunction = (Mix2) functions[0];
+			return mix( mixFunction.color1, color, mixFunction.weight / 100 );
 		}
 
 		// convert RGB to HSL
@@ -386,7 +389,11 @@ public class ColorFunctions
 	//---- class Mix ----------------------------------------------------------
 
 	/**
-	 * Mix two colors.
+	 * Mix two colors using {@link ColorFunctions#mix(Color, Color, float)}.
+	 * First color is passed to {@link #apply(float[])}.
+	 * Second color is {@link #color2}.
+	 * <p>
+	 * Use {@link Mix2} to tint or shade color.
 	 *
 	 * @since 1.6
 	 */
@@ -420,4 +427,44 @@ public class ColorFunctions
 			return String.format( "mix(#%08x,%.0f%%)", color2.getRGB(), weight );
 		}
 	}
+
+	//---- class Mix2 ---------------------------------------------------------
+
+	/**
+	 * Mix two colors using {@link ColorFunctions#mix(Color, Color, float)}.
+	 * First color is {@link #color1}.
+	 * Second color is passed to {@link #apply(float[])}.
+	 *
+	 * @since 3.6
+	 */
+	public static class Mix2
+		implements ColorFunction
+	{
+		public final Color color1;
+		public final float weight;
+
+		public Mix2( Color color1, float weight ) {
+			this.color1 = color1;
+			this.weight = weight;
+		}
+
+		@Override
+		public void apply( float[] hsla ) {
+			// convert from HSL to RGB because color mixing is done on RGB values
+			Color color2 = HSLColor.toRGB( hsla[0], hsla[1], hsla[2], hsla[3] / 100 );
+
+			// mix
+			Color color = mix( color1, color2, weight / 100 );
+
+			// convert RGB to HSL
+			float[] hsl = HSLColor.fromRGB( color );
+			System.arraycopy( hsl, 0, hsla, 0, hsl.length );
+			hsla[3] = (color.getAlpha() / 255f) * 100;
+		}
+
+		@Override
+		public String toString() {
+			return String.format( "mix2(#%08x,%.0f%%)", color1.getRGB(), weight );
+		}
+	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/util/FontUtils.java

@@ -80,7 +80,7 @@ public class FontUtils
 
 	/**
 	 * Loads a font family previously registered via {@link #registerFontFamilyLoader(String, Runnable)}.
-	 * If the family is already loaded or no londer is registered for that family, nothing happens.
+	 * If the family is already loaded or no loader is registered for that family, nothing happens.
 	 */
 	public static void loadFontFamily( String family ) {
 		if( !hasLoaders() )
@@ -109,7 +109,7 @@ public class FontUtils
 	}
 
 	/**
-	 * Returns all font familiy names available in the graphics environment.
+	 * Returns all font family names available in the graphics environment.
 	 * This invokes {@link GraphicsEnvironment#getAvailableFontFamilyNames()} and
 	 * appends families registered for lazy loading via {@link #registerFontFamilyLoader(String, Runnable)}
 	 * to the result.

flatlaf-core/src/main/java/com/formdev/flatlaf/util/HiDPIUtils.java

@@ -16,15 +16,21 @@
 
 package com.formdev.flatlaf.util;
 
+import java.awt.Color;
+import java.awt.Component;
 import java.awt.Font;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
+import java.awt.Rectangle;
 import java.awt.font.GlyphVector;
 import java.awt.geom.AffineTransform;
 import java.awt.geom.Rectangle2D;
 import java.text.AttributedCharacterIterator;
 import javax.swing.JComponent;
+import javax.swing.RepaintManager;
+import com.formdev.flatlaf.FlatLaf;
 import com.formdev.flatlaf.FlatSystemProperties;
+import com.formdev.flatlaf.ui.StackUtils;
 
 /**
  * @author Karl Tauber
@@ -192,7 +198,8 @@ public class HiDPIUtils
 
 				case "Inter":
 				case "Inter Light":
-				case "Inter Semi Bold":
+				case "Inter Semi Bold":	// Inter v3
+				case "Inter SemiBold":	// Inter v4
 				case "Roboto":
 				case "Roboto Light":
 				case "Roboto Medium":
@@ -319,6 +326,258 @@ public class HiDPIUtils
 			public void drawGlyphVector( GlyphVector g, float x, float y ) {
 				super.drawGlyphVector( g, x, y + yCorrection );
 			}
+
+			@Override
+			public void fillRect( int x, int y, int width, int height ) {
+				// fix hard coded black color in HRuleView.paint() of '<hr noshade>'
+				if( super.getColor() == Color.black &&
+					StackUtils.wasInvokedFrom( "javax.swing.text.html.HRuleView", "paint", 4 ) )
+				{
+					super.setColor( FlatLaf.isLafDark() ? Color.lightGray : Color.darkGray );
+					super.fillRect( x, y, width, height );
+					super.setColor( Color.black );
+				} else
+					super.fillRect( x, y, width, height );
+			}
 		};
 	}
+
+	/**
+	 * Repaints the given component.
+	 * <p>
+	 * See {@link #repaint(Component, int, int, int, int)} for more details.
+	 *
+	 * @since 3.5
+	 */
+	public static void repaint( Component c ) {
+		repaint( c, 0, 0, c.getWidth(), c.getHeight() );
+	}
+
+	/**
+	 * Repaints the given component area.
+	 * <p>
+	 * See {@link #repaint(Component, int, int, int, int)} for more details.
+	 *
+	 * @since 3.5
+	 */
+	public static void repaint( Component c, Rectangle r ) {
+		repaint( c, r.x, r.y, r.width, r.height );
+	}
+
+	/**
+	 * Repaints the given component area.
+	 * <p>
+	 * Invokes {@link Component#repaint(int, int, int, int)} on the given component,
+	 * <p>
+	 * Use this method, instead of {@code Component.repaint(...)},
+	 * to fix a problem in Swing when using scale factors that end on .25 or .75
+	 * (e.g. 1.25, 1.75, 2.25, etc) and repainting single components, which may not
+	 * repaint right and/or bottom 1px edge of component.
+	 * <p>
+	 * The problem may occur under following conditions:
+	 * <ul>
+	 *   <li>using Java 9 or later
+	 *   <li>system scale factor is 125%, 175%, 225%, ...
+	 *       (Windows only; Java on macOS and Linux does not support fractional scale factors)
+	 *   <li>repaint whole component or right/bottom area of component
+	 *   <li>component is opaque; or component is contained in a opaque container
+	 *       that has same right/bottom bounds as component
+	 *   <li>component has bounds that Java/Swing scales different when repainting components
+	 * </ul>
+	 *
+	 * @since 3.5
+	 */
+	public static void repaint( Component c, int x, int y, int width, int height ) {
+		// repaint given component area
+		//   Always invoke repaint() on given component, even if also invoked (below)
+		//   on one of its ancestors, for the case that component overrides that method.
+		//   Also RepaintManager "merges" the two repaints into one.
+		c.repaint( x, y, width, height );
+
+		if( RepaintManager.currentManager( c ) instanceof HiDPIRepaintManager )
+			return;
+
+		// if necessary, also repaint given area in first ancestor that is larger than component
+		// to avoid clipping issue (see needsSpecialRepaint())
+		if( needsSpecialRepaint( c, x, y, width, height ) ) {
+			int x2 = x + c.getX();
+			int y2 = y + c.getY();
+			for( Component p = c.getParent(); p != null; p = p.getParent() ) {
+				x2 += p.getX();
+				y2 += p.getY();
+				if( x2 + width < p.getWidth() && y2 + height < p.getHeight() ) {
+					p.repaint( x2, y2, width, height );
+					break;
+				}
+			}
+		}
+	}
+
+	/**
+	 * There is a problem in Swing, when using scale factors that end on .25 or .75
+	 * (e.g. 1.25, 1.75, 2.25, etc) and repainting single components, which may not
+	 * repaint right and/or bottom 1px edge of component.
+	 * <p>
+	 * The component is first painted to an in-memory image,
+	 * and then that image is copied to the screen.
+	 * See {@code javax.swing.RepaintManager.PaintManager#paintDoubleBufferedFPScales()}.
+	 * <p>
+	 * There are two clipping rectangles involved when copying the image to the screen:
+	 * {@code sun.java2d.SunGraphics2D#devClip} and
+	 * {@code sun.java2d.SunGraphics2D#usrClip}.
+	 * <p>
+	 * {@code devClip} is the device clipping in physical pixels.
+	 * It gets the bounds of the painting component, which is either the passed component,
+	 * or if it is non-opaque, then the first opaque ancestor of the passed component.
+	 * It is calculated in {@code sun.java2d.SunGraphics2D#constrain()} while
+	 * getting a graphics context via {@link JComponent#getGraphics()}.
+	 * <p>
+	 * {@code usrClip} is the user clipping, which is set via {@link Graphics} clipping methods.
+	 * This is done in {@code javax.swing.RepaintManager.PaintManager#paintDoubleBufferedFPScales()}.
+	 * <p>
+	 * The intersection of {@code devClip} and {@code usrClip}
+	 * (computed in {@code sun.java2d.SunGraphics2D#validateCompClip()})
+	 * is used to copy the image to the screen.
+	 * <p>
+	 * Unfortunately different scaling/rounding strategies are used to calculate
+	 * the two clipping rectangles, which is the reason of the issue.
+	 * <p>
+	 * {@code devClip} (see {@code sun.java2d.SunGraphics2D#constrain()}):
+	 * <pre>{@code
+	 * int devX = (int) (x * scale);
+	 * int devWidth = Math.round( width * scale )
+	 * }</pre>
+	 * {@code usrClip} (see {@code javax.swing.RepaintManager.PaintManager#paintDoubleBufferedFPScales()}):
+	 * <pre>{@code
+	 * int usrX = (int) Math.ceil( (x * scale) - 0.5 );
+	 * int usrWidth = ((int) Math.ceil( ((x + width) * scale) - 0.5 )) - usrX;
+	 * }</pre>
+	 * X/Y coordinates are always rounded down for {@code devClip}, but rounded up for {@code usrClip}.
+	 * Width/height calculation is also different.
+	 */
+	private static boolean needsSpecialRepaint( Component c, int x, int y, int width, int height ) {
+		// no special repaint necessary for Java 8 or for macOS and Linux
+		// (Java on those platforms does not support fractional scale factors)
+		if( !SystemInfo.isJava_9_orLater || !SystemInfo.isWindows )
+			return false;
+
+		// check whether repaint area is empty or no component given
+		// (same checks as in javax.swing.RepaintManager.addDirtyRegion0())
+		if( width <= 0 || height <= 0 || c == null )
+			return false;
+
+		// check whether component has zero size
+		// (same checks as in javax.swing.RepaintManager.addDirtyRegion0())
+		int compWidth = c.getWidth();
+		int compHeight = c.getHeight();
+		if( compWidth <= 0 || compHeight <= 0 )
+			return false;
+
+		// check whether repaint area does span to right or bottom component edges
+		// (in this case, {@code devClip} is always larger than {@code usrClip})
+		if( x + width < compWidth && y + height < compHeight )
+			return false;
+
+		// if component is not opaque, Swing uses the first opaque ancestor for painting
+		if( !c.isOpaque() ) {
+			int x2 = x;
+			int y2 = y;
+			for( Component p = c.getParent(); p != null; p = p.getParent() ) {
+				x2 += p.getX();
+				y2 += p.getY();
+				if( p.isOpaque() ) {
+					// check whether repaint area does span to right or bottom edges
+					// of the opaque ancestor component
+					// (in this case, {@code devClip} is always larger than {@code usrClip})
+					if( x2 + width < p.getWidth() && y2 + height < p.getHeight() )
+						return false;
+					break;
+				}
+			}
+		}
+
+		// check whether Special repaint is necessary for current scale factor
+		// (doing this check late because it temporary allocates some memory)
+		double scaleFactor = UIScale.getSystemScaleFactor( c.getGraphicsConfiguration() );
+		double fraction = scaleFactor - (int) scaleFactor;
+		if( fraction == 0 || fraction == 0.5 )
+			return false;
+
+		return true;
+	}
+
+	/**
+	 * Installs a {@link HiDPIRepaintManager} on Windows when running in Java 9+,
+	 * but only if default repaint manager is currently installed.
+	 * <p>
+	 * Invoke once on application startup.
+	 * Compatible with all/other LaFs.
+	 *
+	 * @since 3.5
+	 */
+	public static void installHiDPIRepaintManager() {
+		if( !SystemInfo.isJava_9_orLater || !SystemInfo.isWindows )
+			return;
+
+		RepaintManager manager = RepaintManager.currentManager( (Component) null );
+		if( manager.getClass() == RepaintManager.class )
+			RepaintManager.setCurrentManager( new HiDPIRepaintManager() );
+	}
+
+	/**
+	 * Similar to {@link #repaint(Component, int, int, int, int)},
+	 * but invokes callback instead of invoking {@link Component#repaint(int, int, int, int)}.
+	 * <p>
+	 * For use in custom repaint managers.
+	 *
+	 * @since 3.5
+	 */
+	public static void addDirtyRegion( JComponent c, int x, int y, int width, int height, DirtyRegionCallback callback ) {
+		if( needsSpecialRepaint( c, x, y, width, height ) ) {
+			int x2 = x + c.getX();
+			int y2 = y + c.getY();
+			for( Component p = c.getParent(); p != null; p = p.getParent() ) {
+				if( x2 + width < p.getWidth() && y2 + height < p.getHeight() && p instanceof JComponent ) {
+					callback.addDirtyRegion( (JComponent) p, x2, y2, width, height );
+					return;
+				}
+				x2 += p.getX();
+				y2 += p.getY();
+			}
+		}
+
+		callback.addDirtyRegion( c, x, y, width, height );
+	}
+
+	//---- interface DirtyRegionCallback --------------------------------------
+
+	/**
+	 * For {@link HiDPIUtils#addDirtyRegion(JComponent, int, int, int, int, DirtyRegionCallback)}.
+	 *
+	 * @since 3.5
+	 */
+	public interface DirtyRegionCallback {
+		void addDirtyRegion( JComponent c, int x, int y, int w, int h );
+	}
+
+	//---- class HiDPIRepaintManager ------------------------------------------
+
+	/**
+	 * A repaint manager that fixes a problem in Swing when repainting components
+	 * at some scale factors (e.g. 125%, 175%, etc) on Windows.
+	 * <p>
+	 * Use {@link HiDPIUtils#installHiDPIRepaintManager()} to install it.
+	 * <p>
+	 * See {@link HiDPIUtils#repaint(Component, int, int, int, int)} for details.
+	 *
+	 * @since 3.5
+	 */
+	public static class HiDPIRepaintManager
+		extends RepaintManager
+	{
+		@Override
+		public void addDirtyRegion( JComponent c, int x, int y, int w, int h ) {
+			HiDPIUtils.addDirtyRegion( c, x, y, w, h, super::addDirtyRegion );
+		}
+	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/util/NativeLibrary.java

@@ -116,7 +116,11 @@ public class NativeLibrary
 		try {
 			// for development environment
 			if( "file".equals( libraryUrl.getProtocol() ) ) {
-				File libraryFile = new File( libraryUrl.getPath() );
+				String binPath = libraryUrl.getPath();
+				String srcPath = binPath.replace( "flatlaf-core/bin/main/", "flatlaf-core/src/main/resources/" );
+				File libraryFile = new File( srcPath ); // use from 'src' folder if available
+				if( !libraryFile.isFile() )
+					libraryFile = new File( binPath ); // use from 'bin' or 'output' folder if available
 				if( libraryFile.isFile() ) {
 					// load library without copying
 					System.load( libraryFile.getCanonicalPath() );

flatlaf-core/src/main/java/com/formdev/flatlaf/util/SystemInfo.java

@@ -31,6 +31,7 @@ public class SystemInfo
 	public static final boolean isWindows;
 	public static final boolean isMacOS;
 	public static final boolean isLinux;
+	/** @since 3.6 */ public static final boolean isUnknownOS;
 
 	// OS versions
 	public static final long osVersion;
@@ -59,6 +60,7 @@ public class SystemInfo
 	public static final boolean isJetBrainsJVM_11_orLater;
 
 	// UI toolkits
+	/** @since 3.6 */ public static final boolean isGNOME;
 	public static final boolean isKDE;
 
 	// other
@@ -75,6 +77,7 @@ public class SystemInfo
 		isWindows = osName.startsWith( "windows" );
 		isMacOS = osName.startsWith( "mac" );
 		isLinux = osName.startsWith( "linux" );
+		isUnknownOS = !isWindows && !isMacOS && !isLinux;
 
 		// OS versions
 		osVersion = scanVersion( System.getProperty( "os.version" ) );
@@ -104,7 +107,13 @@ public class SystemInfo
 		isJetBrainsJVM_11_orLater = isJetBrainsJVM && isJava_11_orLater;
 
 		// UI toolkits
-		isKDE = (isLinux && System.getenv( "KDE_FULL_SESSION" ) != null);
+		String desktop = isLinux ? System.getenv( "XDG_CURRENT_DESKTOP" ) : null;
+		isGNOME = (isLinux &&
+			(System.getenv( "GNOME_DESKTOP_SESSION_ID" ) != null ||
+			 (desktop != null && desktop.contains( "GNOME" ))));
+		isKDE = (isLinux &&
+			(System.getenv( "KDE_FULL_SESSION" ) != null ||
+			 (desktop != null && desktop.contains( "KDE" ))));
 
 		// other
 		isProjector = Boolean.getBoolean( "org.jetbrains.projector.server.enable" );

flatlaf-core/src/main/java/com/formdev/flatlaf/util/UIScale.java

@@ -33,6 +33,7 @@ import javax.swing.plaf.DimensionUIResource;
 import javax.swing.plaf.FontUIResource;
 import javax.swing.plaf.InsetsUIResource;
 import javax.swing.plaf.UIResource;
+import com.formdev.flatlaf.FlatLaf;
 import com.formdev.flatlaf.FlatSystemProperties;
 
 /**
@@ -188,7 +189,9 @@ public class UIScale
 		// because even if we are on a HiDPI display it is not sure
 		// that a larger font size is set by the current LaF
 		// (e.g. can avoid large icons with small text)
-		Font font = UIManager.getFont( "defaultFont" );
+		Font font = null;
+		if( UIManager.getLookAndFeel() instanceof FlatLaf )
+			font = UIManager.getFont( "defaultFont" );
 		if( font == null )
 			font = UIManager.getFont( "Label.font" );
 
@@ -204,7 +207,7 @@ public class UIScale
 		if( SystemInfo.isWindows ) {
 			// Special handling for Windows to be compatible with OS scaling,
 			// which distinguish between "screen scaling" and "text scaling".
-			//  - Windows "screen scaling" scales everything (text, icon, gaps, etc)
+			//  - Windows "screen scaling" scales everything (text, icon, gaps, etc.)
 			//    and may have different scaling factors for each screen.
 			//  - Windows "text scaling" increases only the font size, but on all screens.
 			//
@@ -244,6 +247,16 @@ public class UIScale
 	}
 
 	private static float computeScaleFactor( Font font ) {
+		String customFontSizeDivider = System.getProperty( "flatlaf.uiScale.fontSizeDivider" );
+		if( customFontSizeDivider != null ) {
+			try {
+				float fontSizeDivider = Math.max( Integer.parseInt( customFontSizeDivider ), 10 );
+				return font.getSize() / fontSizeDivider;
+			} catch( NumberFormatException ex ) {
+				// ignore
+			}
+		}
+
 		// default font size
 		float fontSizeDivider = 12f;