release 3.5.3

the removed use of floating point font size is similar to what is done in JDK for GTK Look and Feel:
- https://bugs.openjdk.org/browse/JDK-6979979
- 306f12db9e

.github/workflows/ci.yml

@@ -9,6 +9,14 @@ on:
       - '*'
     tags:
       - '[0-9]*'
+    paths-ignore:
+      - '**.md'
+      - '.*'
+      - '**/.settings/**'
+      - 'flatlaf-core/svg/**'
+      - 'flatlaf-testing/dumps/**'
+      - 'flatlaf-testing/misc/**'
+      - 'images/**'
 
 jobs:
   build:
@@ -24,22 +32,24 @@ jobs:
           - 8
           - 11  # LTS
           - 17  # LTS
+          - 21  # LTS
+          - 23  # latest
         toolchain: [""]
-        include:
-          - java: 17
-            toolchain: 21  # latest
+#        include:
+#          - java: 21
+#            toolchain: 22  # latest
 
     steps:
       - uses: actions/checkout@v4
 
-      - uses: gradle/wrapper-validation-action@v1
+      - uses: gradle/wrapper-validation-action@v2
         if: matrix.java == '8'
 
       - name: Setup Java ${{ matrix.java }}
         uses: actions/setup-java@v4
         with:
           java-version: ${{ matrix.java }}
-          distribution: temurin  # Java 8, 11 and 17 are pre-installed on ubuntu-latest
+          distribution: temurin  # Java 8, 11, 17 and 21 are pre-installed on ubuntu-latest
           cache: gradle
 
       - name: Check with Error Prone

.github/workflows/fonts.yml

@@ -13,6 +13,8 @@ on:
             - 'flatlaf-fonts/**'
             - '.github/workflows/fonts.yml'
             - 'gradle/wrapper/gradle-wrapper.properties'
+            - '!**.md'
+            - '!**/.settings/**'
 
 jobs:
     Fonts:

.github/workflows/natives.yml

@@ -13,6 +13,8 @@ on:
             - 'flatlaf-natives/**'
             - '.github/workflows/natives.yml'
             - 'gradle/wrapper/gradle-wrapper.properties'
+            - '!**.md'
+            - '!**/.settings/**'
 
 jobs:
     Natives:
@@ -28,7 +30,7 @@ jobs:
         steps:
             - uses: actions/checkout@v4
 
-            - uses: gradle/wrapper-validation-action@v1
+            - uses: gradle/wrapper-validation-action@v2
 
             - name: Setup Java 11
               uses: actions/setup-java@v4

.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 oss.sonatype.org
+        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:
+          OSSRH_USERNAME: ${{ secrets.OSSRH_USERNAME }}
+          OSSRH_PASSWORD: ${{ secrets.OSSRH_PASSWORD }}

CHANGELOG.md

@@ -1,18 +1,199 @@
 FlatLaf Change Log
 ==================
 
-## 3.4-SNAPSHOT
-
-#### New features and improvements
-
-- Native libraries: System property `flatlaf.nativeLibraryPath` now supports
-  loading native libraries named the same as on Maven central. Improved log
-  messages for loading fails.
-- Fonts: Updated **Inter** to
-  [v4.0](https://github.com/rsms/inter/releases/tag/v4.0).
+## 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)
 
@@ -35,7 +216,7 @@ FlatLaf Change Log
 #### Fixed bugs
 
 - Button and ToggleButton: Selected buttons did not use explicitly set
-  foreground color. (issue 756)
+  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))
@@ -788,7 +969,7 @@ 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 +33,20 @@ FlatLaf can use 3rd party themes created for IntelliJ Platform (see
 Sponsors
 --------
 
+### Current Sponsors
+
+[![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
 ----
 
@@ -311,6 +317,9 @@ Applications using FlatLaf
 
 - ![New](images/new.svg) ![Sponsor](images/sponsor.svg)
   [BGBlitz](https://www.bgblitz.com/) (**commercial**) - professional Backgammon
+- ![New](images/new.svg) [MCreator](https://github.com/MCreator/MCreator) - 
+  software used to make Minecraft Java Edition mods, Minecraft Bedrock Edition Add-Ons, 
+  and data packs without programming knowledge
 - ![New](images/new.svg) [MapTool](https://github.com/RPTools/maptool) - virtual
   Tabletop for playing role-playing games
 - [MegaMek](https://github.com/MegaMek/megamek),

build.gradle.kts

@@ -18,6 +18,12 @@ import net.ltgt.gradle.errorprone.errorprone
 
 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
 

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"
 				}
 			}
 
@@ -124,7 +124,7 @@ 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/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 {
@@ -127,6 +148,8 @@ 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" ),

flatlaf-core/flatlaf-core-sigtest.txt

@@ -1,5 +1,5 @@
 #Signature file v4.1
-#Version 3.3
+#Version 3.5.2
 
 CLSS public abstract interface com.formdev.flatlaf.FlatClientProperties
 fld public final static java.lang.String BUTTON_TYPE = "JButton.buttonType"
@@ -12,7 +12,13 @@ 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"
@@ -94,6 +100,7 @@ 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"
@@ -217,6 +224,7 @@ meth public static java.util.Map<java.lang.String,java.lang.Class<?>> getStyleab
 meth public static java.util.Map<java.lang.String,java.lang.String> getGlobalExtraDefaults()
 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>)
@@ -290,6 +298,8 @@ fld public final static java.lang.String UPDATE_UI_ON_SYSTEM_FONT_CHANGE = "flat
 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"
@@ -623,16 +633,33 @@ 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)
@@ -1131,6 +1158,31 @@ 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

@@ -102,6 +102,17 @@ 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 +129,6 @@ 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 ---------------------------------------------------------
 
@@ -257,19 +260,116 @@ 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 --------------------------------------------------------------
 
 	/**
@@ -361,7 +461,7 @@ 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}
@@ -381,13 +481,55 @@ 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}.
@@ -397,7 +539,7 @@ 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}
@@ -413,6 +555,8 @@ 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}
 	 *
@@ -427,6 +571,8 @@ public interface FlatClientProperties
 	 * 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}
 	 *
@@ -441,6 +587,8 @@ 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}
 	 *
@@ -455,6 +603,8 @@ 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}
 	 *
@@ -465,7 +615,7 @@ 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}
@@ -477,7 +627,7 @@ 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}
@@ -486,10 +636,24 @@ 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}
 	 *
@@ -847,7 +1011,7 @@ 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),
@@ -959,7 +1123,7 @@ public interface FlatClientProperties
 	 * <strong>Allowed Values</strong>
 	 *     {@link SwingConstants#LEFT},
 	 *     {@link SwingConstants#RIGHT},
-	 *     {@link #TABBED_PANE_TAB_ROTATION_NONE}, (default)
+	 *     {@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}
@@ -1208,8 +1372,8 @@ 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}
@@ -1263,6 +1427,44 @@ 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/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;
@@ -119,6 +120,46 @@ 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)}.

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

@@ -23,13 +23,15 @@ import java.io.InputStream;
 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.
@@ -71,7 +73,8 @@ 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 +119,16 @@ 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

@@ -82,7 +82,7 @@ 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
@@ -99,7 +99,7 @@ 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)
@@ -120,7 +120,7 @@ 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
@@ -135,6 +135,18 @@ 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 on macOS 14.4+ where it is {@code false}
+	 *
+	 * @since 3.5.2
+	 */
+	String USE_ROUNDED_POPUP_BORDER = "flatlaf.useRoundedPopupBorder";
+
 	/**
 	 * Specifies whether vertical text position is corrected when UI is scaled on HiDPI screens.
 	 * <p>
@@ -204,6 +216,16 @@ public interface FlatSystemProperties
 	 */
 	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/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() )
@@ -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/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
@@ -173,8 +178,29 @@ debug*/
 		targetBottomY = popupLocation.y + popupSize.height;
 
 		// install own event queue to suppress mouse events when mouse is moved within safe triangle
-		if( subMenuEventQueue == null )
-			subMenuEventQueue = new SubMenuEventQueue();
+		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

@@ -161,7 +161,7 @@ class UIDefaultsLoader
 						classLoader = FlatLaf.class.getClassLoader();
 
 					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 )
 								properties.load( in );
@@ -171,7 +171,7 @@ class UIDefaultsLoader
 					// load from package URL
 					URL packageUrl = (URL) source;
 					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 +183,7 @@ 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;
 
@@ -294,6 +294,14 @@ 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 )
@@ -630,14 +638,18 @@ class UIDefaultsLoader
 			// Syntax: top,left,bottom,right[,lineColor[,lineThickness[,arc]]]
 			List<String> parts = splitFunctionParams( value, ',' );
 			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 );
 			};

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/FlatWindowAbstractIcon.java

@@ -60,23 +60,24 @@ public abstract class FlatWindowAbstractIcon
 
 	@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 ) {
+	/** @since 3.5.2 */
+	@Override
+	protected void paintBackground( Component c, Graphics2D g, int x, int y ) {
 		Color background = FlatButtonUI.buttonStateColor( c, null, null, null, hoverBackground, pressedBackground );
 		if( background != null ) {
 			// disable antialiasing for background rectangle painting to avoid blurry 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 );
 
+			// fill background of whole component
 			g.setColor( FlatUIUtils.deriveColor( background, c.getBackground() ) );
-			g.fillRect( 0, 0, width, height );
+			g.fillRect( 0, 0, c.getWidth(), c.getHeight() );
 
 			g.setRenderingHint( RenderingHints.KEY_ANTIALIASING, oldHint );
 		}

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

@@ -135,7 +135,7 @@ 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();
 		}
@@ -277,7 +277,7 @@ 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;
 
@@ -300,6 +302,10 @@ 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 +314,11 @@ 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 +330,7 @@ public class FlatButtonUI
 				} else
 					installStyle( b );
 				b.revalidate();
-				b.repaint();
+				HiDPIUtils.repaint( b );
 				break;
 		}
 	}
@@ -583,9 +589,16 @@ 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 +644,6 @@ 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;
 
@@ -906,7 +917,7 @@ 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();
@@ -918,5 +929,17 @@ 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/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;
 
@@ -220,7 +221,7 @@ public class FlatComboBoxUI
 
 			private void repaintArrowButton() {
 				if( arrowButton != null && !comboBox.isEditable() )
-					arrowButton.repaint();
+					HiDPIUtils.repaint( arrowButton );
 			}
 		};
 		comboBox.addMouseListener( hoverListener );
@@ -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 );

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 ) );
@@ -401,7 +409,7 @@ public class FlatFileChooserUI
 	/** @since 2.3 */
 	public static class FlatShortcutsPanel
 		extends JToolBar
-		implements PropertyChangeListener
+		implements PropertyChangeListener, Scrollable
 	{
 		private final JFileChooser fc;
 
@@ -420,6 +428,7 @@ 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 );
@@ -429,7 +438,7 @@ 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 );
 
@@ -461,7 +470,7 @@ 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 );
@@ -487,8 +496,10 @@ 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 );
@@ -498,32 +509,6 @@ 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 );
@@ -592,6 +577,8 @@ public class FlatFileChooserUI
 			buttonGroup.clearSelection();
 		}
 
+		//---- interface PropertyChangeListener ----
+
 		@Override
 		public void propertyChange( PropertyChangeEvent e ) {
 			switch( e.getPropertyName() ) {
@@ -600,6 +587,41 @@ 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 +1,289 @@
+/*
+ * 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.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*/
+		int fontBaseSize = c.getFont().getSize();
+		if( styleSheet.getPointSize( 7 ) != 36f ||
+			styleSheet.getPointSize( 4 ) == fontBaseSize )
+		  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 " + c.getFont().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
-			super.propertyChange( e );
+			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

@@ -23,13 +23,20 @@ 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
  */
@@ -41,7 +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 */
@@ -52,15 +59,28 @@ 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;
 	}
@@ -70,11 +90,31 @@ public class FlatLineBorder
 		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;
 
@@ -182,7 +183,7 @@ public class FlatListUI
 				case FlatClientProperties.STYLE_CLASS:
 					installStyle();
 					list.revalidate();
-					list.repaint();
+					HiDPIUtils.repaint( list );
 					break;
 			}
 		};
@@ -205,7 +206,7 @@ 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) );
 				}
 			}
 		};
@@ -324,8 +325,7 @@ public class FlatListUI
 			(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.
@@ -374,7 +374,15 @@ 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 );
@@ -440,7 +448,8 @@ 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
 	 */

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

@@ -47,6 +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;
 
 /**
@@ -136,6 +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 );
 	}
@@ -159,7 +168,7 @@ public class FlatMenuUI
 				JMenu menu = (JMenu) e.getSource();
 				if( menu.isTopLevelMenu() && menu.isRolloverEnabled() ) {
 					menu.getModel().setRollover( rollover );
-					menu.repaint();
+					HiDPIUtils.repaint( menu );
 				}
 			}
 		};
@@ -167,7 +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 */

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;
@@ -103,7 +106,26 @@ 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 );
+		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;
+		}
+
+		FlatNativeLibrary.nativeLibrary = nativeLibrary;
 	}
 
 	private static NativeLibrary createNativeLibrary( String classifier, String ext ) {
@@ -117,9 +139,9 @@ class FlatNativeLibrary
 				if( library.isLoaded() )
 					return library;
 
-				LoggingFacade.INSTANCE.logSevere( "Did not find library '" + System.mapLibraryName( libraryName )
-					+ "' in java.library.path '" + System.getProperty( "java.library.path" )
-					+ "', using extracted library instead", null );
+				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')
@@ -138,11 +160,11 @@ class FlatNativeLibrary
 						return new NativeLibrary( libraryFile2, true );
 				}
 
-				LoggingFacade.INSTANCE.logSevere( "Did not find library '"
+				LoggingFacade.INSTANCE.logSevere( "FlatLaf: Native library '"
 					+ libraryFile.getName()
 					+ (libraryName2 != null ? ("' or '" + libraryName2) : "")
-					+ "' in '" + libraryFile.getParentFile().getAbsolutePath()
-					+ "', using extracted library instead", null );
+					+ "' not found in '" + libraryFile.getParentFile().getAbsolutePath()
+					+ "'. Using extracted native library instead.", null );
 			}
 		}
 
@@ -177,21 +199,39 @@ class FlatNativeLibrary
 
 		// build library file
 		String libraryName = buildLibraryName( jarFile, classifier, ext );
-		File parent = jarFile.getParentFile();
+		File jarDir = jarFile.getParentFile();
 
 		// check whether native library exists in same directory as jar
-		File libraryFile = new File( parent, libraryName );
+		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( parent.getName().equalsIgnoreCase( "lib" ) ) {
-			libraryFile = new File( parent.getParentFile(), "bin/" + libraryName );
+		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;
 	}
@@ -224,6 +264,10 @@ class FlatNativeLibrary
 	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;

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;
@@ -35,6 +36,8 @@ import com.formdev.flatlaf.util.SystemInfo;
  */
 class FlatNativeLinuxLibrary
 {
+	private static int API_VERSION_LINUX = 3001;
+
 	/**
 	 * Checks whether native library is loaded/available.
 	 * <p>
@@ -42,7 +45,7 @@ class FlatNativeLinuxLibrary
 	 *              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
@@ -94,7 +97,11 @@ 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

@@ -16,7 +16,9 @@
 
 package com.formdev.flatlaf.ui;
 
+import java.awt.Rectangle;
 import java.awt.Window;
+import com.formdev.flatlaf.util.SystemInfo;
 
 /**
  * Native methods for macOS.
@@ -42,6 +44,8 @@ import java.awt.Window;
  */
 public class FlatNativeMacLibrary
 {
+	private static int API_VERSION_MACOS = 2001;
+
 	/**
 	 * Checks whether native library is loaded/available.
 	 * <p>
@@ -49,8 +53,19 @@ public class FlatNativeMacLibrary
 	 *              method of this class. Otherwise, the native library may not be loaded.
 	 */
 	public static boolean isLoaded() {
-		return FlatNativeLibrary.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

@@ -21,11 +21,12 @@ 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;
@@ -218,13 +219,13 @@ 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( !isSupported() )
 			return;
 
-		nativeProvider.updateTitleBarInfo( window, titleBarHeight, hitTestSpots,
+		nativeProvider.updateTitleBarInfo( window, titleBarHeight, captionHitTestCallback,
 			appIconBounds, minimizeButtonBounds, maximizeButtonBounds, closeButtonBounds );
 	}
 
@@ -270,7 +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 );
 

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

@@ -30,6 +30,8 @@ import com.formdev.flatlaf.util.SystemInfo;
  */
 public class FlatNativeWindowsLibrary
 {
+	private static int API_VERSION_WINDOWS = 1001;
+
 	private static long osBuildNumber = Long.MIN_VALUE;
 
 	/**
@@ -39,7 +41,7 @@ public class FlatNativeWindowsLibrary
 	 *              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 );
 	}
 
 	/**

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;
@@ -35,12 +36,16 @@ 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 +63,7 @@ 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;
 
@@ -76,6 +82,8 @@ public class FlatPopupFactory
 	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
@@ -88,15 +96,28 @@ 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 ) {
-			NonFlashingPopup popup = new NonFlashingPopup( getPopupForScreenOfOwner( owner, contents, x, y, true ), contents );
-			if( popup.popupWindow != null && SystemInfo.isMacOS && FlatNativeMacLibrary.isLoaded() )
+			NonFlashingPopup popup = new NonFlashingPopup( getPopupForScreenOfOwner( owner, contents, x, y, true ), owner, contents );
+			if( popup.popupWindow != null && isMacOSBorderSupported() )
 				setupRoundedBorder( popup.popupWindow, owner, contents );
 			return popup;
 		}
@@ -105,7 +126,7 @@ public class FlatPopupFactory
 		if( isWindows11BorderSupported() &&
 			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 )
 				setupRoundedBorder( popup.popupWindow, owner, contents );
 			return popup;
@@ -116,7 +137,11 @@ 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.getGraphicsConfiguration();
+		return (gc != null && gc.isTranslucencyCapable())
+			? new DropShadowPopup( popupForScreenOfOwner, owner, contents )
+			: new NonFlashingPopup( popupForScreenOfOwner, owner, contents );
 	}
 
 	/**
@@ -227,6 +252,24 @@ public class FlatPopupFactory
 		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 -----------------------------------------------------------
 
 	/**
@@ -316,19 +359,29 @@ public class FlatPopupFactory
 	//---- 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 boolean isMacOSBorderSupported() {
+		// do not use rounded border on macOS 14.4+ because it may freeze the application
+		// and crash the macOS WindowServer process (reports vary from Finder restarts to OS restarts)
+		// https://github.com/apache/netbeans/issues/7560#issuecomment-2226439215
+		// https://github.com/apache/netbeans/issues/6647#issuecomment-2070124442
+		boolean isMacOS_14_4_orLater = (SystemInfo.osVersion >= SystemInfo.toVersion( 14, 4, 0, 0 ));
+
+		return SystemInfo.isMacOS &&
+			FlatSystemProperties.getBoolean( FlatSystemProperties.USE_ROUNDED_POPUP_BORDER, !isMacOS_14_4_orLater ) &&
+			FlatNativeMacLibrary.isLoaded();
 	}
 
 	private static void setupRoundedBorder( Window popupWindow, Component owner, Component contents ) {
-		// make sure that the native window is created
-		if( !popupWindow.isDisplayable() )
-			popupWindow.addNotify();
-
 		int borderCornerRadius = getBorderCornerRadius( owner, contents );
 		float borderWidth = getRoundedBorderWidth( owner, contents );
 
 		// get Swing border color
-		Color borderColor = null; // use system default color
+		Color borderColor;
 		if( contents instanceof JComponent ) {
 			Border border = ((JComponent)contents).getBorder();
 			border = FlatUIUtils.unwrapNonUIResourceBorder( border );
@@ -340,11 +393,33 @@ public class FlatPopupFactory
 				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 );
@@ -490,18 +565,31 @@ public class FlatPopupFactory
 
 	//---- 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 );
@@ -515,8 +603,27 @@ 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 ) {
 				showPopupAndFixLocation( delegate, popupWindow );
 
@@ -540,13 +647,36 @@ public class FlatPopupFactory
 		}
 
 		@Override
-		public void hide() {
+		public final void hide() {
+			if( disposed )
+				return;
+			disposed = true;
+
+			// immediately hide non-heavy weight popups or combobox popups
+			if( !(popupWindow instanceof JWindow) || contents instanceof BasicComboPopup ) {
+				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;
 			}
 
@@ -557,6 +687,28 @@ public class FlatPopupFactory
 				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 ----------------------------------------------
@@ -564,8 +716,6 @@ public class FlatPopupFactory
 	private class DropShadowPopup
 		extends NonFlashingPopup
 	{
-		private final Component owner;
-
 		// light weight
 		private JComponent lightComp;
 		private Border oldBorder;
@@ -580,11 +730,11 @@ 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 )
@@ -600,24 +750,24 @@ 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 ) );
@@ -654,6 +804,23 @@ 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" ),
@@ -662,14 +829,14 @@ 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 ) {
@@ -680,10 +847,11 @@ public class FlatPopupFactory
 		}
 
 		@Override
-		public void hide() {
+		void hideImpl() {
 			if( dropShadowDelegate != null ) {
 				dropShadowDelegate.hide();
 				dropShadowDelegate = null;
+				dropShadowPanel2 = null;
 			}
 
 			if( mediumWeightPanel != null ) {
@@ -692,7 +860,7 @@ public class FlatPopupFactory
 				mediumWeightPanel = null;
 			}
 
-			super.hide();
+			super.hideImpl();
 
 			if( dropShadowWindow != null ) {
 				dropShadowWindow.setBackground( oldDropShadowWindowBackground );
@@ -776,5 +944,26 @@ 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 ) {
+			super.reset( contents, ownerX, ownerY );
+
+			if( dropShadowWindow != null ) {
+				// set preferred size of drop shadow panel
+				Dimension prefSize = popupWindow.getPreferredSize();
+				Insets insets = dropShadowPanel2.getInsets();
+				int w = prefSize.width + insets.left + insets.right;
+				int h = prefSize.height + insets.top + insets.bottom;
+				dropShadowPanel2.setPreferredSize( new Dimension( w, h ) );
+				dropShadowPanel2.invalidate();
+				dropShadowWindow.pack();
+
+				// update drop shadow popup window location
+				int x = popupWindow.getX() - insets.left;
+				int y = popupWindow.getY() - insets.top;
+				dropShadowWindow.setLocation( x, y );
+			}
+		}
 	}
 }

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

@@ -239,11 +239,13 @@ 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() );
+		Rectangle screenBounds = gc.getBounds();
 		Insets screenInsets = Toolkit.getDefaultToolkit().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;
 		}
 	}

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

@@ -28,8 +28,6 @@ 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;
@@ -41,7 +39,6 @@ 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;
@@ -50,6 +47,7 @@ import javax.swing.plaf.RootPaneUI;
 import javax.swing.plaf.UIResource;
 import javax.swing.plaf.basic.BasicRootPaneUI;
 import com.formdev.flatlaf.FlatClientProperties;
+import com.formdev.flatlaf.FlatLaf;
 import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.SystemInfo;
 import com.formdev.flatlaf.util.UIScale;
@@ -87,8 +85,8 @@ 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();
@@ -106,6 +104,7 @@ public class FlatRootPaneUI
 			installBorder();
 
 		installNativeWindowBorder();
+		macInstallFullWindowContentSupport();
 	}
 
 	protected void installBorder() {
@@ -122,6 +121,7 @@ public class FlatRootPaneUI
 
 		uninstallNativeWindowBorder();
 		uninstallClientDecorations();
+		macUninstallFullWindowContentSupport();
 		rootPane = null;
 	}
 
@@ -155,6 +155,8 @@ public class FlatRootPaneUI
 			if( background == null || background instanceof UIResource )
 				parent.setBackground( UIManager.getColor( "control" ) );
 		}
+
+		macClearBackgroundForTranslucentWindow( c );
 	}
 
 	@Override
@@ -174,55 +176,20 @@ 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 */
@@ -302,19 +269,141 @@ 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 );
@@ -359,6 +448,33 @@ 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;
@@ -367,14 +483,43 @@ 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 )
+					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 */
@@ -410,23 +555,21 @@ 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();
-
-				width = Math.max( width, menuBarSize.width );
-				height += menuBarSize.height;
+				if( menuBar != null && menuBar.isVisible() ) {
+					Dimension menuBarSize = getSizeFunc.apply( menuBar );
+					width = Math.max( width, menuBarSize.width );
+					height += menuBarSize.height;
+				}
 			}
 
 			Insets insets = rootPane.getInsets();
@@ -451,12 +594,29 @@ 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;
-				titlePane.setBounds( 0, 0, width, prefHeight );
-				nextY += prefHeight;
+				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;
 			}
 
 			// glass pane
@@ -467,7 +627,7 @@ 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();
@@ -475,13 +635,23 @@ 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 ) );

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":
@@ -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/FlatScrollPaneUI.java

@@ -55,6 +55,7 @@ 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;
 
@@ -209,7 +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 ) {
@@ -297,11 +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;
 
@@ -321,14 +322,14 @@ 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":
@@ -339,7 +340,7 @@ public class FlatScrollPaneUI
 						borderShared = null;
 						installStyle();
 						scrollpane.revalidate();
-						scrollpane.repaint();
+						HiDPIUtils.repaint( scrollpane );
 					}
 					break;
 			}
@@ -538,14 +539,14 @@ public class FlatScrollPaneUI
 		public void focusGained( FocusEvent e ) {
 			// necessary to update focus border
 			if( scrollpane.getBorder() instanceof FlatBorder )
-				scrollpane.repaint();
+				HiDPIUtils.repaint( scrollpane );
 		}
 
 		@Override
 		public void focusLost( FocusEvent e ) {
 			// necessary to update focus border
 			if( scrollpane.getBorder() instanceof FlatBorder )
-				scrollpane.repaint();
+				HiDPIUtils.repaint( scrollpane );
 		}
 	}
 

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 ) {
+		// 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
 
-			// 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 );
-
 			// 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;
 
 /**
@@ -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

@@ -84,7 +84,7 @@ 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;
@@ -227,6 +227,15 @@ public class FlatSplitPaneUI
 			((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
@@ -292,6 +301,10 @@ public class FlatSplitPaneUI
 					// necessary to show/hide one-touch buttons on expand/collapse
 					doLayout();
 					break;
+
+				case FlatClientProperties.SPLIT_PANE_EXPANDABLE_SIDE:
+					revalidate();
+					break;
 			}
 		}
 

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

@@ -40,6 +40,7 @@ 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;
 
@@ -709,7 +710,7 @@ 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/FlatTabbedPaneUI.java

@@ -98,6 +98,7 @@ import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
 import com.formdev.flatlaf.ui.FlatStylingSupport.UnknownStyleException;
 import com.formdev.flatlaf.util.Animator;
 import com.formdev.flatlaf.util.CubicBezierEasing;
+import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.JavaCompatibility;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.StringUtils;
@@ -182,7 +183,7 @@ import com.formdev.flatlaf.util.UIScale;
  */
 public class FlatTabbedPaneUI
 	extends BasicTabbedPaneUI
-	implements StyleableUI
+	implements StyleableUI, FlatTitlePane.TitleBarCaptionHitTest
 {
 	// tab type
 	/** @since 2 */ protected static final int TAB_TYPE_UNDERLINED = 0;
@@ -895,7 +896,7 @@ public class FlatTabbedPaneUI
 			}
 		}
 
-		tabPane.repaint( r );
+		HiDPIUtils.repaint( tabPane, r );
 	}
 
 	private boolean inCalculateEqual;
@@ -1684,7 +1685,7 @@ debug*/
 			w - (ci.left / 100f) - (ci.right / 100f), h - (ci.top / 100f) - (ci.bottom / 100f) ), false );
 
 		// add gap for selected tab to path
-		if( getTabType() == TAB_TYPE_CARD ) {
+		if( getTabType() == TAB_TYPE_CARD && selectedIndex >= 0 ) {
 			float csh = scale( (float) contentSeparatorHeight );
 
 			Rectangle tabRect = getTabBounds( tabPane, selectedIndex );
@@ -2300,6 +2301,32 @@ debug*/
 		return (rects[last].y + rects[last].height) - rects[0].y;
 	}
 
+	//---- interface FlatTitlePane.TitleBarCaptionHitTest ----
+
+	/** @since 3.4 */
+	@Override
+	public Boolean isTitleBarCaptionAt( int x, int y ) {
+		// Note: not using tabForCoordinate() here because this may validate layout and cause dead lock
+
+		if( moreTabsButton != null ) {
+			// convert x,y from JTabbedPane coordinate space to ScrollableTabPanel coordinate space
+			Point viewPosition = tabViewport.getViewPosition();
+			x = x - tabViewport.getX() + viewPosition.x;
+			y = y - tabViewport.getY() + viewPosition.y;
+
+			// check whether point is within viewport
+			if( !tabViewport.getViewRect().contains( x, y ) )
+				return null; // check children
+		}
+
+		for( int i = 0; i < rects.length; i++ ) {
+			if( rects[i].contains( x, y ) )
+				return false;
+		}
+
+		return null; // check children
+	}
+
 	//---- class TabCloseButton -----------------------------------------------
 
 	private static class TabCloseButton
@@ -2570,19 +2597,19 @@ debug*/
 		@Override
 		public void popupMenuWillBecomeVisible( PopupMenuEvent e ) {
 			popupVisible = true;
-			repaint();
+			HiDPIUtils.repaint( this );
 		}
 
 		@Override
 		public void popupMenuWillBecomeInvisible( PopupMenuEvent e ) {
 			popupVisible = false;
-			repaint();
+			HiDPIUtils.repaint( this );
 		}
 
 		@Override
 		public void popupMenuCanceled( PopupMenuEvent e ) {
 			popupVisible = false;
-			repaint();
+			HiDPIUtils.repaint( this );
 		}
 	}
 
@@ -3091,7 +3118,7 @@ debug*/
 
 				case TABBED_PANE_SHOW_TAB_SEPARATORS:
 				case TABBED_PANE_TAB_TYPE:
-					tabPane.repaint();
+					HiDPIUtils.repaint( tabPane );
 					break;
 
 				case TABBED_PANE_SHOW_CONTENT_SEPARATOR:
@@ -3114,14 +3141,14 @@ debug*/
 				case TABBED_PANE_TAB_ICON_PLACEMENT:
 				case TABBED_PANE_TAB_CLOSABLE:
 					tabPane.revalidate();
-					tabPane.repaint();
+					HiDPIUtils.repaint( tabPane );
 					break;
 
 				case TABBED_PANE_LEADING_COMPONENT:
 					uninstallLeadingComponent();
 					installLeadingComponent();
 					tabPane.revalidate();
-					tabPane.repaint();
+					HiDPIUtils.repaint( tabPane );
 					ensureSelectedTabIsVisibleLater();
 					break;
 
@@ -3129,7 +3156,7 @@ debug*/
 					uninstallTrailingComponent();
 					installTrailingComponent();
 					tabPane.revalidate();
-					tabPane.repaint();
+					HiDPIUtils.repaint( tabPane );
 					ensureSelectedTabIsVisibleLater();
 					break;
 
@@ -3137,7 +3164,7 @@ debug*/
 				case STYLE_CLASS:
 					installStyle();
 					tabPane.revalidate();
-					tabPane.repaint();
+					HiDPIUtils.repaint( tabPane );
 					break;
 			}
 		}
@@ -3161,7 +3188,7 @@ debug*/
 				case TABBED_PANE_TAB_ALIGNMENT:
 				case TABBED_PANE_TAB_CLOSABLE:
 					tabPane.revalidate();
-					tabPane.repaint();
+					HiDPIUtils.repaint( tabPane );
 					break;
 			}
 		}
@@ -3756,9 +3783,20 @@ debug*/
 			boolean hideDisabledScrollButtons = (scrollButtonsPolicy == AS_NEEDED_SINGLE && scrollButtonsPlacement == BOTH);
 			boolean trailingScrollButtons = (scrollButtonsPlacement == TRAILING);
 
-			// for right-to-left always use "more tabs" button for horizontal scrolling
+			// For right-to-left, always use "more tabs" button for horizontal scrolling
 			// because methods scrollForward() and scrollBackward() in class
-			// BasicTabbedPaneUI.ScrollableTabSupport do not work for right-to-left
+			// BasicTabbedPaneUI.ScrollableTabSupport do not work for right-to-left.
+			//
+			// One problem is that BasicTabbedPaneUI.getClosestTab(), which is used
+			// to compute leadingTabIndex, does not work for right-to-left because is uses "binary" search
+			// on rects[] to find tab, but rects[] is ordered in reverse order for right-to-left.
+			// So leadingTabIndex is either zero or tabCount.
+			// Therefore increasing/decreasing leadingTabIndex in scrollForward()
+			// and scrollBackward() does not work as expected.
+			// Also backward/forward scroll buttons are not correctly enabled/disabled.
+			//
+			// Fixing this would require replacing nearly whole functionality of class
+			// BasicTabbedPaneUI.ScrollableTabSupport, which is not possible because it is private.
 			boolean leftToRight = isLeftToRight();
 			if( !leftToRight && isHorizontalTabPlacement( tabPane.getTabPlacement() ) ) {
 				useMoreTabsButton = true;
@@ -3840,6 +3878,8 @@ debug*/
 							w -= buttonWidth;
 							moreTabsButtonVisible = true;
 						}
+
+						// layout scroll buttons
 						if( useScrollButtons ) {
 							// the tabViewport view size is set in
 							// BasicTabbedPaneUI.TabbedPaneScrollLayout.calculateTabRects(),
@@ -3847,30 +3887,28 @@ debug*/
 							Point viewPosition = tabViewport.getViewPosition();
 							Dimension viewSize = tabViewport.getViewSize();
 
+							// layout forward button on trailing side
+							if( !hideDisabledScrollButtons || viewSize.width - viewPosition.x > w ) {
+								int buttonWidth = forwardButton.getPreferredSize().width;
+								forwardButton.setBounds( x + w - buttonWidth, y, buttonWidth, h );
+								w -= buttonWidth;
+								forwardButtonVisible = true;
+							}
+
 							// layout backward button
 							if( !hideDisabledScrollButtons || viewPosition.x > 0 ) {
 								int buttonWidth = backwardButton.getPreferredSize().width;
 								if( trailingScrollButtons ) {
 									// on trailing side
-									backwardButton.setBounds( leftToRight ? (x + w - buttonWidth) : x, y, buttonWidth, h );
-									x += leftToRight ? 0 : buttonWidth;
+									backwardButton.setBounds( x + w - buttonWidth, y, buttonWidth, h );
 								} else {
 									// on leading side
-									backwardButton.setBounds( leftToRight ? x : (x + w - buttonWidth), y, buttonWidth, h );
-									x += leftToRight ? buttonWidth : 0;
+									backwardButton.setBounds( x, y, buttonWidth, h );
+									x += buttonWidth;
 								}
 								w -= buttonWidth;
 								backwardButtonVisible = true;
 							}
-
-							// layout forward button on trailing side
-							if( !hideDisabledScrollButtons || viewSize.width - viewPosition.x > w ) {
-								int buttonWidth = forwardButton.getPreferredSize().width;
-								forwardButton.setBounds( leftToRight ? (x + w - buttonWidth) : x, y, buttonWidth, h );
-								x += leftToRight ? 0 : buttonWidth;
-								w -= buttonWidth;
-								forwardButtonVisible = true;
-							}
 						}
 					}
 
@@ -3916,6 +3954,8 @@ debug*/
 							h -= buttonHeight;
 							moreTabsButtonVisible = true;
 						}
+
+						// layout scroll buttons
 						if( useScrollButtons ) {
 							// the tabViewport view size is set in
 							// BasicTabbedPaneUI.TabbedPaneScrollLayout.calculateTabRects(),
@@ -3923,6 +3963,14 @@ debug*/
 							Point viewPosition = tabViewport.getViewPosition();
 							Dimension viewSize = tabViewport.getViewSize();
 
+							// layout forward button on bottom side
+							if( !hideDisabledScrollButtons || viewSize.height - viewPosition.y > h ) {
+								int buttonHeight = forwardButton.getPreferredSize().height;
+								forwardButton.setBounds( x, y + h - buttonHeight, w, buttonHeight );
+								h -= buttonHeight;
+								forwardButtonVisible = true;
+							}
+
 							// layout backward button
 							if( !hideDisabledScrollButtons || viewPosition.y > 0 ) {
 								int buttonHeight = backwardButton.getPreferredSize().height;
@@ -3937,14 +3985,6 @@ debug*/
 								h -= buttonHeight;
 								backwardButtonVisible = true;
 							}
-
-							// layout forward button on bottom side
-							if( !hideDisabledScrollButtons || viewSize.height - viewPosition.y > h ) {
-								int buttonHeight = forwardButton.getPreferredSize().height;
-								forwardButton.setBounds( x, y + h - buttonHeight, w, buttonHeight );
-								h -= buttonHeight;
-								forwardButtonVisible = true;
-							}
 						}
 					}
 
@@ -3985,10 +4025,8 @@ debug*/
 	//---- class RunWithOriginalLayoutManagerDelegateAction -------------------
 
 	private static class RunWithOriginalLayoutManagerDelegateAction
-		implements Action
+		extends FlatUIAction
 	{
-		private final Action delegate;
-
 		static void install( ActionMap map, String key ) {
 			Action oldAction = map.get( key );
 			if( oldAction == null || oldAction instanceof RunWithOriginalLayoutManagerDelegateAction )
@@ -3998,24 +4036,9 @@ debug*/
 		}
 
 		private RunWithOriginalLayoutManagerDelegateAction( Action delegate ) {
-			this.delegate = delegate;
+			super( delegate );
 		}
 
-		@Override
-		public Object getValue( String key ) {
-			return delegate.getValue( key );
-		}
-
-		@Override
-		public boolean isEnabled() {
-			return delegate.isEnabled();
-		}
-
-		@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 ) {}
-
 		@Override
 		public void actionPerformed( ActionEvent e ) {
 			JTabbedPane tabbedPane = (JTabbedPane) e.getSource();

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

@@ -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;
 
@@ -234,8 +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

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

@@ -24,31 +24,49 @@ 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.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;
@@ -88,7 +106,10 @@ 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 -->
  *
@@ -115,6 +136,8 @@ 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;
@@ -127,6 +150,9 @@ public class FlatTableUI
 	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 ) {
@@ -153,6 +179,8 @@ 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();
 
@@ -240,6 +268,28 @@ 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;
@@ -248,11 +298,14 @@ public class FlatTableUI
 				case FlatClientProperties.STYLE_CLASS:
 					installStyle();
 					table.revalidate();
-					table.repaint();
+					HiDPIUtils.repaint( table );
 					break;
 			}
 		};
 		table.addPropertyChangeListener( propertyChangeListener );
+
+		if( selectionArc > 0 )
+			installRepaintRoundedSelectionListeners();
 	}
 
 	@Override
@@ -261,6 +314,19 @@ 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
@@ -284,6 +350,18 @@ 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 {
@@ -325,6 +403,8 @@ 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 );
 	}
@@ -387,6 +467,7 @@ 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)
@@ -429,11 +510,11 @@ 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;
 						}
 					}
@@ -451,6 +532,10 @@ 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 );
 	}
 
@@ -496,8 +581,6 @@ 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
@@ -506,10 +589,350 @@ 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 );
 			}
 		}
 	}
@@ -579,4 +1002,36 @@ public class FlatTableUI
 			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

@@ -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

@@ -36,6 +36,7 @@ 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 +47,9 @@ 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 +58,6 @@ 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 +66,7 @@ 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;
@@ -98,7 +99,6 @@ import com.formdev.flatlaf.util.UIScale;
  * @uiDefault TitlePane.showIconBesideTitle					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 +109,8 @@ 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;
@@ -131,7 +132,6 @@ public class FlatTitlePane
 	/** @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;
@@ -150,6 +150,33 @@ public class FlatTitlePane
 
 	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;
 
@@ -178,7 +205,6 @@ public class FlatTitlePane
 		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();
@@ -187,11 +213,18 @@ 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() );
 	}
@@ -234,6 +267,11 @@ 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 +285,7 @@ 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 +333,9 @@ public class FlatTitlePane
 							horizontalGlue.getWidth(), titleLabel.getHeight() );
 					}
 				}
+
+				// clear hit-test cache
+				lastCaptionHitTestTime = 0;
 			}
 		} );
 
@@ -318,6 +359,10 @@ public class FlatTitlePane
 			@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 ) ) );
@@ -338,6 +383,13 @@ public class FlatTitlePane
 			buttonPanel.add( restoreButton );
 		}
 		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 ) {
@@ -347,6 +399,12 @@ public class FlatTitlePane
 				// allow the button to shrink if space is rare
 				return new Dimension( UIScale.scale( buttonMinimumWidth ), super.getMinimumSize().height );
 			}
+			@Override
+			public Dimension getMaximumSize() {
+				// allow the button to fill whole button area height
+				// see also BasicMenuUI.getMaximumSize()
+				return new Dimension( super.getMaximumSize().width, Short.MAX_VALUE );
+			}
 		};
 		button.setFocusable( false );
 		button.setContentAreaFilled( false );
@@ -417,7 +475,9 @@ 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 ) {
@@ -443,7 +503,7 @@ 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 +528,13 @@ 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 +589,11 @@ 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 +605,9 @@ 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,
@@ -620,21 +695,45 @@ 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 );
+			g.drawLine( 0, y, getWidth(), y );
 		}
-		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.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 paintRect( Graphics g, Color color, Rectangle r ) {
+	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;
 
@@ -645,6 +744,9 @@ public class FlatTitlePane
 
 	@Override
 	protected void paintComponent( Graphics g ) {
+		if( isFullWindowContent() )
+			return;
+
 		// 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)
@@ -653,16 +755,6 @@ public class FlatTitlePane
 		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
-	}
-
 	/**
 	 * Iconifies the window.
 	 */
@@ -732,7 +824,8 @@ 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();
 
@@ -846,6 +939,10 @@ 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 +963,14 @@ 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() ) {
@@ -928,71 +1028,17 @@ public class FlatTitlePane
 			}
 		}
 
-		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;
@@ -1007,18 +1053,122 @@ public class FlatTitlePane
 			: null;
 	}
 
-	protected Rectangle getNativeHitTestSpot( JComponent c ) {
-		Dimension size = c.getSize();
-		if( size.width <= 0 || size.height <= 0 )
-			return null;
+	/**
+	 * 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;
+		}
 
-		Point location = SwingUtilities.convertPoint( c, 0, 0, window );
-		Rectangle r = new Rectangle( location, size );
-		return r;
+		// 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
+
+		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;
@@ -1041,7 +1191,7 @@ 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;
@@ -1060,7 +1210,7 @@ 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 );
 		}
 
@@ -1116,7 +1266,7 @@ 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 ) {
@@ -1125,7 +1275,7 @@ 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(),
@@ -1224,10 +1374,7 @@ public class FlatTitlePane
 			activeChanged( true );
 			updateNativeTitleBarHeightAndHitTestSpots();
 
-			if( !SystemInfo.isWindows_11_orLater && hasNativeCustomDecoration() )
-				WindowTopBorder.getInstance().repaintBorder( FlatTitlePane.this );
-
-			repaintWindowBorder();
+			repaintBorder();
 		}
 
 		@Override
@@ -1235,10 +1382,22 @@ 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
@@ -1275,7 +1434,7 @@ debug*/
 			}
 
 			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() ) {
@@ -1302,7 +1461,7 @@ 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
@@ -1415,4 +1574,36 @@ 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

@@ -36,6 +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;
 
 /**
@@ -131,7 +132,7 @@ public class FlatToolBarSeparatorUI
 				} else
 					installStyle( s );
 				s.revalidate();
-				s.repaint();
+				HiDPIUtils.repaint( s );
 				break;
 		}
 	}

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;
@@ -443,7 +444,7 @@ public class FlatToolBarUI
 
 		// repaint button group
 		if( gr != null )
-			toolBar.repaint( gr );
+			HiDPIUtils.repaint(toolBar, gr );
 	}
 
 	private ButtonGroup getButtonGroup( AbstractButton b ) {
@@ -453,6 +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 ------------------------------
 
 	/**
@@ -521,8 +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;
 
@@ -310,7 +311,7 @@ public class FlatTreeUI
 				switch( e.getPropertyName() ) {
 					case TREE_WIDE_SELECTION:
 					case TREE_PAINT_SELECTION:
-						tree.repaint();
+						HiDPIUtils.repaint( tree );
 						break;
 
 					case "dropLocation":
@@ -325,7 +326,7 @@ public class FlatTreeUI
 					case STYLE_CLASS:
 						installStyle();
 						tree.revalidate();
-						tree.repaint();
+						HiDPIUtils.repaint( tree );
 						break;
 
 					case "enabled":
@@ -353,7 +354,7 @@ 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 +371,14 @@ 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) );
 					}
 				}
 			}

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

@@ -60,6 +60,7 @@ 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 +124,11 @@ 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;
+	}
+
 	public static Color getUIColor( String key, int defaultColorRGB ) {
 		Color color = UIManager.getColor( key );
 		return (color != null) ? color : new Color( defaultColorRGB );
@@ -304,6 +310,10 @@ public class FlatUIUtils
 		if( parent instanceof JTable && ((JTable)parent).getEditorComponent() == c )
 			return true;
 
+		// 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
 		//   Tree.cellEditor is set in sun.swing.FilePane.editFileName()
@@ -596,28 +606,55 @@ 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;
@@ -775,7 +812,7 @@ 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) -> {
@@ -1310,13 +1347,13 @@ 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/FlatWindowResizer.java

@@ -42,6 +42,7 @@ 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;
@@ -191,7 +192,7 @@ public abstract class FlatWindowResizer
 	protected abstract Dimension getWindowMinimumSize();
 	protected abstract Dimension getWindowMaximumSize();
 
-	protected void beginResizing( int direction ) {}
+	protected void beginResizing( int resizeDir ) {}
 	protected void endResizing() {}
 
 	//---- interface PropertyChangeListener ----
@@ -234,17 +235,46 @@ 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 );
+			Container cont = rootPane.getLayeredPane();
+			cont.add( centerComp, WINDOW_RESIZER_LAYER, 4 );
+
 			// 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() {
+			Container cont = topDragComp.getParent();
+			cont.remove( centerComp );
+
+			super.uninstall();
+		}
+
+		@Override
+		public void doLayout() {
+			super.doLayout();
+
+			centerComp.setBounds( 0, 0, resizeComp.getWidth(), resizeComp.getHeight() );
+		}
+
 		@Override
 		protected void addNotify() {
 			Container parent = resizeComp.getParent();
@@ -299,20 +329,17 @@ 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 );
-				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;
+			GraphicsConfiguration gc = window.getGraphicsConfiguration();
+			Rectangle bounds = gc.getBounds();
+			Insets insets = window.getToolkit().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 );
 		}
 
 		@Override
@@ -346,6 +373,18 @@ public abstract class FlatWindowResizer
 		public void windowStateChanged( WindowEvent e ) {
 			updateVisibility();
 		}
+
+		@Override
+		protected void beginResizing( int resizeDir ) {
+			centerComp.setCursor( getPredefinedCursor( resizeDir ) );
+			centerComp.setVisible( true );
+		}
+
+		@Override
+		protected void endResizing() {
+			centerComp.setVisible( false );
+			centerComp.setCursor( null );
+		}
 	}
 
 	//---- class InternalFrameResizer -----------------------------------------
@@ -427,7 +466,18 @@ public abstract class FlatWindowResizer
 		}
 
 		@Override
-		protected void beginResizing( int direction ) {
+		protected void beginResizing( int resizeDir ) {
+			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 +585,7 @@ 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 );
 		}
 
 		@Override

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

@@ -29,8 +29,8 @@ 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;
@@ -89,7 +89,7 @@ class FlatWindowsNativeWindowBorder
 			return null;
 
 		// check whether native library was successfully loaded
-		if( !FlatNativeLibrary.isLoaded() )
+		if( !FlatNativeWindowsLibrary.isLoaded() )
 			return null;
 
 		// create new instance
@@ -159,7 +159,7 @@ 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 +168,7 @@ 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 );
@@ -288,8 +288,8 @@ class FlatWindowsNativeWindowBorder
 		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 +340,61 @@ 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;
 
 			// 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);
+			// return HTTOP if mouse is over top resize border
+			//   - hovering mouse shows vertical resize cursor
+			//   - left-click and drag vertically resizes window
+			if( isOnResizeBorder )
+				return HTTOP;
 
+			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 isOnResizeBorder ? HTTOP : HTCAPTION;
+
+				// return HTCAPTION if mouse is over title bar
+				//   - right-click shows system menu
+				//   - double-left-click maximizes/restores window size
+				return HTCAPTION;
 			}
 
-			return isOnResizeBorder ? HTTOP : HTCLIENT;
+			// return HTCLIENT
+			//   - Windows ignores mouse events in this area
+			return 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/JavaCompatibility2.java

@@ -16,6 +16,7 @@
 
 package com.formdev.flatlaf.ui;
 
+import java.io.File;
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.MethodType;
@@ -25,6 +26,7 @@ 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;
@@ -88,4 +90,64 @@ public class JavaCompatibility2
 			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/util/HiDPIUtils.java

@@ -16,14 +16,17 @@
 
 package com.formdev.flatlaf.util;
 
+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.FlatSystemProperties;
 
 /**
@@ -322,4 +325,243 @@ public class HiDPIUtils
 			}
 		};
 	}
+
+	/**
+	 * 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/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" );
 
@@ -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;
 

flatlaf-core/src/main/resources/com/formdev/flatlaf/FlatLaf.properties

@@ -739,6 +739,8 @@ Table.rowHeight = 20
 Table.showHorizontalLines = false
 Table.showVerticalLines = false
 Table.showTrailingVerticalLine = false
+Table.paintOutsideAlternateRows = false
+Table.editorSelectAllOnStartEditing = true
 Table.consistentHomeEndKeyBehavior = true
 Table.intercellSpacing = 0,0
 Table.scrollPaneBorder = com.formdev.flatlaf.ui.FlatScrollPaneBorder
@@ -829,7 +831,6 @@ TitlePane.centerTitleIfMenuBarEmbedded = true
 TitlePane.showIconBesideTitle = false
 TitlePane.menuBarTitleGap = 40
 TitlePane.menuBarTitleMinimumGap = 12
-TitlePane.menuBarResizeHeight = 4
 TitlePane.closeIcon = com.formdev.flatlaf.icons.FlatWindowCloseIcon
 TitlePane.iconifyIcon = com.formdev.flatlaf.icons.FlatWindowIconifyIcon
 TitlePane.maximizeIcon = com.formdev.flatlaf.icons.FlatWindowMaximizeIcon

flatlaf-core/src/test/java/com/formdev/flatlaf/TestUIDefaultsLoader.java

@@ -84,10 +84,12 @@ public class TestUIDefaultsLoader
 	void parseBorders() {
 		Insets insets = new Insets( 1,2,3,4 );
 		assertBorderEquals( new FlatEmptyBorder( insets ), "1,2,3,4" );
+		assertBorderEquals( new FlatEmptyBorder( insets ), "1,2,3,4,,," );
 		assertBorderEquals( new FlatLineBorder( insets, Color.red ), "1,2,3,4,#f00" );
-		assertBorderEquals( new FlatLineBorder( insets, Color.red, 2.5f, 0 ), "1,2,3,4,#f00,2.5" );
+		assertBorderEquals( new FlatLineBorder( insets, Color.red, 2.5f, -1 ), "1,2,3,4,#f00,2.5" );
 		assertBorderEquals( new FlatLineBorder( insets, Color.red, 2.5f, 6 ), "1,2,3,4,#f00,2.5,6" );
 		assertBorderEquals( new FlatLineBorder( insets, Color.red, 1, 6 ), "1,2,3,4,#f00,,6" );
+		assertBorderEquals( new FlatLineBorder( insets, null, 1, 6 ), "1,2,3,4,,,6" );
 	}
 
 	private void assertBorderEquals( Border expected, String actualStyle ) {

flatlaf-core/src/test/java/com/formdev/flatlaf/ui/TestFlatHTML.java

@@ -0,0 +1,113 @@
+/*
+ * 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 static org.junit.jupiter.api.Assertions.assertEquals;
+import java.util.Locale;
+import javax.swing.JComponent;
+import javax.swing.JLabel;
+import javax.swing.UIManager;
+import javax.swing.plaf.basic.BasicHTML;
+import javax.swing.text.BadLocationException;
+import javax.swing.text.Document;
+import javax.swing.text.View;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+/**
+ * @author Karl Tauber
+ */
+public class TestFlatHTML
+{
+	private final String body = "some <small>small</small> text";
+	private final String bodyInBody = "<body>" + body + "</body>";
+	private final String bodyPlain = "some small text";
+
+	@BeforeAll
+	static void setup() {
+		TestUtils.setup( false );
+		TestUtils.scaleFont( 2 );
+	}
+
+	@AfterAll
+	static void cleanup() {
+		TestUtils.cleanup();
+	}
+
+	@Test
+	void simple() {
+		testHtmlBaseSize( "<html>${BASE_SIZE_IN_HEAD}" + body + "</html>", bodyPlain );
+		testHtmlBaseSize( "<html>${BASE_SIZE_IN_HEAD}" + bodyInBody + "</html>", bodyPlain );
+	}
+
+	@Test
+	void htmlWithHeadTag() {
+		testHtmlBaseSize( "<html><head>${BASE_SIZE}<title>test</title><head>" + body + "</html>", bodyPlain );
+		testHtmlBaseSize( "<html><head>${BASE_SIZE}<title>test</title><head>" + bodyInBody + "</html>", bodyPlain );
+
+		testHtmlBaseSize( "<html><head id=\"abc\">${BASE_SIZE}<title>test</title><head>" + body + "</html>", bodyPlain );
+		testHtmlBaseSize( "<html><head id=\"abc\">${BASE_SIZE}<title>test</title><head>" + bodyInBody + "</html>", bodyPlain );
+	}
+
+	@Test
+	void htmlWithStyleTag() {
+		testHtmlBaseSize( "<html>${BASE_SIZE}<style>body { color: #f00; }</style>" + bodyInBody + "</html>", bodyPlain );
+		testHtmlBaseSize( "<html>${BASE_SIZE}<style>body { color: #f00; }</style><h1>header1</h1>" + body + "</html>", "header1\n" + bodyPlain );
+
+		testHtmlBaseSize( "<html>${BASE_SIZE}<style type='text/css'>body { color: #f00; }</style>" + bodyInBody + "</html>", bodyPlain );
+		testHtmlBaseSize( "<html>${BASE_SIZE}<style type='text/css'>body { color: #f00; }</style><h1>header1</h1>" + body + "</html>", "header1\n" + bodyPlain );
+	}
+
+	private void testHtmlBaseSize( String html, String expectedPlain ) {
+		testHtmlBaseSizeImpl( html, expectedPlain );
+		testHtmlBaseSizeImpl( html.toUpperCase( Locale.ENGLISH ), expectedPlain.toUpperCase( Locale.ENGLISH ) );
+	}
+
+	private void testHtmlBaseSizeImpl( String html, String expectedPlain ) {
+		String baseSize = "<style>BASE_SIZE " + UIManager.getFont( "Label.font" ).getSize() + "</style>";
+		String baseSizeInHead = "<head>" + baseSize + "</head>";
+
+		String expectedHtml = html.replace( "${BASE_SIZE}", baseSize ).replace( "${BASE_SIZE_IN_HEAD}", baseSizeInHead );
+		html = html.replace( "${BASE_SIZE}", "" ).replace( "${BASE_SIZE_IN_HEAD}", "" );
+
+		testHtml( html, expectedHtml, expectedPlain );
+	}
+
+	private void testHtml( String html, String expectedHtml, String expectedPlain ) {
+		FlatHTML.testUpdateRenderer = (c, newHtml) -> {
+			assertEquals( expectedHtml, newHtml );
+			assertEquals( expectedPlain, getPlainText( c ) );
+		};
+		new JLabel( html );
+		FlatHTML.testUpdateRenderer = null;
+	}
+
+	private String getPlainText( JComponent c ) {
+		View view = (View) c.getClientProperty( BasicHTML.propertyKey );
+		if( view == null )
+			return null;
+
+		Document doc = view.getDocument();
+		try {
+			return doc.getText( 0, doc.getLength() ).trim();
+		} catch( BadLocationException ex ) {
+			ex.printStackTrace();
+			return null;
+		}
+	}
+}

flatlaf-core/src/test/java/com/formdev/flatlaf/ui/TestFlatStyleableInfo.java

@@ -253,7 +253,8 @@ public class TestFlatStyleableInfo
 		FlatLabelUI ui = (FlatLabelUI) c.getUI();
 
 		Map<String, Class<?>> expected = expectedMap(
-			"disabledForeground", Color.class
+			"disabledForeground", Color.class,
+			"arc", int.class
 		);
 
 		assertMapEquals( expected, ui.getStyleableInfos( c ) );
@@ -799,6 +800,8 @@ public class TestFlatStyleableInfo
 			"selectionForeground", Color.class,
 			"selectionInactiveBackground", Color.class,
 			"selectionInactiveForeground", Color.class,
+			"selectionInsets", Insets.class,
+			"selectionArc", int.class,
 
 			// FlatTableCellBorder
 			"cellMargins", Insets.class,
@@ -993,12 +996,20 @@ public class TestFlatStyleableInfo
 			"disabledBorderColor", Color.class,
 			"focusedBorderColor", Color.class,
 			"hoverBorderColor", Color.class,
+			"pressedBorderColor", Color.class,
+
+			"selectedBorderColor", Color.class,
+			"disabledSelectedBorderColor", Color.class,
+			"focusedSelectedBorderColor", Color.class,
+			"hoverSelectedBorderColor", Color.class,
+			"pressedSelectedBorderColor", Color.class,
 
 			"default.borderWidth", float.class,
 			"default.borderColor", Color.class,
 			"default.focusedBorderColor", Color.class,
 			"default.focusColor", Color.class,
 			"default.hoverBorderColor", Color.class,
+			"default.pressedBorderColor", Color.class,
 
 			"toolbar.focusWidth", float.class,
 			"toolbar.focusColor", Color.class,

flatlaf-core/src/test/java/com/formdev/flatlaf/ui/TestFlatStyleableValue.java

@@ -305,6 +305,9 @@ public class TestFlatStyleableValue
 		testColor( c, ui, "buttonPressedArrowColor", 0x123456 );
 
 		testColor( c, ui, "popupBackground", 0x123456 );
+		testInsets( c, ui, "popupInsets", 1,2,3,4 );
+		testInsets( c, ui, "selectionInsets", 1,2,3,4 );
+		testInteger( c, ui, "selectionArc", 123 );
 
 		// border
 		flatRoundBorder( c, ui );
@@ -355,6 +358,7 @@ public class TestFlatStyleableValue
 		FlatLabelUI ui = (FlatLabelUI) c.getUI();
 
 		testColor( c, ui, "disabledForeground", 0x123456 );
+		testInteger( c, ui, "arc", 123 );
 	}
 
 	@Test
@@ -366,6 +370,8 @@ public class TestFlatStyleableValue
 		testColor( c, ui, "selectionForeground", 0x123456 );
 		testColor( c, ui, "selectionInactiveBackground", 0x123456 );
 		testColor( c, ui, "selectionInactiveForeground", 0x123456 );
+		testInsets( c, ui, "selectionInsets", 1,2,3,4 );
+		testInteger( c, ui, "selectionArc", 123 );
 
 		// FlatListCellBorder
 		testInsets( c, ui, "cellMargins", 1,2,3,4 );
@@ -801,6 +807,8 @@ public class TestFlatStyleableValue
 		testColor( c, ui, "selectionForeground", 0x123456 );
 		testColor( c, ui, "selectionInactiveBackground", 0x123456 );
 		testColor( c, ui, "selectionInactiveForeground", 0x901324 );
+		testInsets( c, ui, "selectionInsets", 1,2,3,4 );
+		testInteger( c, ui, "selectionArc", 123 );
 
 		// FlatTableCellBorder
 		testInsets( c, ui, "cellMargins", 1,2,3,4 );
@@ -930,6 +938,8 @@ public class TestFlatStyleableValue
 		testColor( c, ui, "selectionInactiveBackground", 0x123456 );
 		testColor( c, ui, "selectionInactiveForeground", 0x123456 );
 		testColor( c, ui, "selectionBorderColor", 0x123456 );
+		testInsets( c, ui, "selectionInsets", 1,2,3,4 );
+		testInteger( c, ui, "selectionArc", 123 );
 		testBoolean( c, ui, "wideSelection", true );
 		testBoolean( c, ui, "showCellFocusIndicator", true );
 
@@ -955,12 +965,20 @@ public class TestFlatStyleableValue
 		testColor( c, ui, "disabledBorderColor", 0x123456 );
 		testColor( c, ui, "focusedBorderColor", 0x123456 );
 		testColor( c, ui, "hoverBorderColor", 0x123456 );
+		testColor( c, ui, "pressedBorderColor", 0x123456 );
+
+		testColor( c, ui, "selectedBorderColor", 0x123456 );
+		testColor( c, ui, "disabledSelectedBorderColor", 0x123456 );
+		testColor( c, ui, "focusedSelectedBorderColor", 0x123456 );
+		testColor( c, ui, "hoverSelectedBorderColor", 0x123456 );
+		testColor( c, ui, "pressedSelectedBorderColor", 0x123456 );
 
 		testFloat( c, ui, "default.borderWidth", 1.23f );
 		testColor( c, ui, "default.borderColor", 0x123456 );
 		testColor( c, ui, "default.focusedBorderColor", 0x123456 );
 		testColor( c, ui, "default.focusColor", 0x123456 );
 		testColor( c, ui, "default.hoverBorderColor", 0x123456 );
+		testColor( c, ui, "default.pressedBorderColor", 0x123456 );
 
 		testFloat( c, ui, "toolbar.focusWidth", 1.23f );
 		testColor( c, ui, "toolbar.focusColor", 0x123456 );
@@ -1025,12 +1043,20 @@ public class TestFlatStyleableValue
 		testValue( border, "disabledBorderColor", Color.WHITE );
 		testValue( border, "focusedBorderColor", Color.WHITE );
 		testValue( border, "hoverBorderColor", Color.WHITE );
+		testValue( border, "pressedBorderColor", Color.WHITE );
+
+		testValue( border, "selectedBorderColor", Color.WHITE );
+		testValue( border, "disabledSelectedBorderColor", Color.WHITE );
+		testValue( border, "focusedSelectedBorderColor", Color.WHITE );
+		testValue( border, "hoverSelectedBorderColor", Color.WHITE );
+		testValue( border, "pressedSelectedBorderColor", Color.WHITE );
 
 		testValue( border, "default.borderWidth", 2f );
 		testValue( border, "default.borderColor", Color.WHITE );
 		testValue( border, "default.focusedBorderColor", Color.WHITE );
 		testValue( border, "default.focusColor", Color.WHITE );
 		testValue( border, "default.hoverBorderColor", Color.WHITE );
+		testValue( border, "default.pressedBorderColor", Color.WHITE );
 
 		testValue( border, "toolbar.focusWidth", 1.5f );
 		testValue( border, "toolbar.focusColor", Color.WHITE );

flatlaf-core/src/test/java/com/formdev/flatlaf/ui/TestFlatStyling.java

@@ -412,6 +412,7 @@ public class TestFlatStyling
 		FlatLabelUI ui = (FlatLabelUI) c.getUI();
 
 		ui.applyStyle( c, "disabledForeground: #fff" );
+		ui.applyStyle( c, "arc: 8" );
 
 		// JComponent properties
 		ui.applyStyle( c, "background: #fff" );
@@ -986,6 +987,8 @@ public class TestFlatStyling
 		ui.applyStyle( "selectionForeground: #fff" );
 		ui.applyStyle( "selectionInactiveBackground: #fff" );
 		ui.applyStyle( "selectionInactiveForeground: #fff" );
+		ui.applyStyle( "selectionInsets: 1,2,3,4" );
+		ui.applyStyle( "selectionArc: 8" );
 
 		// FlatTableCellBorder
 		ui.applyStyle( "cellMargins: 1,2,3,4" );
@@ -1294,12 +1297,20 @@ public class TestFlatStyling
 		border.applyStyleProperty( "disabledBorderColor", Color.WHITE );
 		border.applyStyleProperty( "focusedBorderColor", Color.WHITE );
 		border.applyStyleProperty( "hoverBorderColor", Color.WHITE );
+		border.applyStyleProperty( "pressedBorderColor", Color.WHITE );
+
+		border.applyStyleProperty( "selectedBorderColor", Color.WHITE );
+		border.applyStyleProperty( "disabledSelectedBorderColor", Color.WHITE );
+		border.applyStyleProperty( "focusedSelectedBorderColor", Color.WHITE );
+		border.applyStyleProperty( "hoverSelectedBorderColor", Color.WHITE );
+		border.applyStyleProperty( "pressedSelectedBorderColor", Color.WHITE );
 
 		border.applyStyleProperty( "default.borderWidth", 2 );
 		border.applyStyleProperty( "default.borderColor", Color.WHITE );
 		border.applyStyleProperty( "default.focusedBorderColor", Color.WHITE );
 		border.applyStyleProperty( "default.focusColor", Color.WHITE );
 		border.applyStyleProperty( "default.hoverBorderColor", Color.WHITE );
+		border.applyStyleProperty( "default.pressedBorderColor", Color.WHITE );
 
 		border.applyStyleProperty( "toolbar.focusWidth", 1.5f );
 		border.applyStyleProperty( "toolbar.focusColor", Color.WHITE );

flatlaf-demo/DemoLaf.properties

@@ -6,7 +6,7 @@
 # when the Demo window is activated.
 
 
-# base theme (light, dark, intellij or darcula)
+# base theme (light, dark, intellij, darcula, maclight or macdark)
 @baseTheme = light
 
 # add you theme defaults here

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/ControlBar.java

@@ -140,8 +140,8 @@ class ControlBar
 			registerSwitchToLookAndFeel( KeyEvent.VK_F9, "com.apple.laf.AquaLookAndFeel" );
 		else if( SystemInfo.isLinux )
 			registerSwitchToLookAndFeel( KeyEvent.VK_F9, "com.sun.java.swing.plaf.gtk.GTKLookAndFeel" );
-		registerSwitchToLookAndFeel( KeyEvent.VK_F12, MetalLookAndFeel.class.getName() );
 		registerSwitchToLookAndFeel( KeyEvent.VK_F11, NimbusLookAndFeel.class.getName() );
+		registerSwitchToLookAndFeel( KeyEvent.VK_F12, MetalLookAndFeel.class.getName() );
 
 		// register Alt+UP and Alt+DOWN to switch to previous/next theme
 		((JComponent)frame.getContentPane()).registerKeyboardAction(
@@ -153,6 +153,9 @@ class ControlBar
 			KeyStroke.getKeyStroke( KeyEvent.VK_DOWN, KeyEvent.ALT_DOWN_MASK ),
 			JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT );
 
+		// register Alt+Shift+F1, F2, ... keys to change system scale factor
+		DemoPrefs.registerSystemScaleFactors( frame );
+
 		// register ESC key to close frame
 		((JComponent)frame.getContentPane()).registerKeyboardAction(
 			e -> {

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DataComponentsPanel.java

@@ -25,6 +25,8 @@ import javax.swing.*;
 import javax.swing.table.*;
 import javax.swing.tree.*;
 import com.formdev.flatlaf.FlatClientProperties;
+import com.formdev.flatlaf.FlatLaf;
+import com.formdev.flatlaf.util.ColorFunctions;
 import net.miginfocom.swing.*;
 
 /**
@@ -93,10 +95,12 @@ class DataComponentsPanel
 
 	private void rowSelectionChanged() {
 		table1.setRowSelectionAllowed( rowSelectionCheckBox.isSelected() );
+		roundedSelectionChanged();
 	}
 
 	private void columnSelectionChanged() {
 		table1.setColumnSelectionAllowed( columnSelectionCheckBox.isSelected() );
+		roundedSelectionChanged();
 	}
 
 	private void showHorizontalLinesChanged() {
@@ -127,6 +131,28 @@ class DataComponentsPanel
 		intercellSpacingCheckBox.setSelected( table1.getRowMargin() != 0 );
 	}
 
+	private void roundedSelectionChanged() {
+		String style = null;
+		if( roundedSelectionCheckBox.isSelected() ) {
+			style = rowSelectionCheckBox.isSelected()
+				? "selectionArc: 6; selectionInsets: 0,1,0,1"
+				: "selectionArc: 6";
+		}
+		table1.putClientProperty( FlatClientProperties.STYLE, style );
+	}
+
+	private void alternatingRowsChanged() {
+		Color alternateRowColor = null;
+		if( alternatingRowsCheckBox.isSelected() ) {
+			Color background = table1.getBackground();
+			alternateRowColor = FlatLaf.isLafDark()
+				? ColorFunctions.lighten( background, 0.05f )
+				: ColorFunctions.darken( background, 0.05f );
+		}
+		UIManager.put( "Table.alternateRowColor", alternateRowColor );
+		table1.repaint();
+	}
+
 	@SuppressWarnings( { "unchecked", "rawtypes" } )
 	private void initComponents() {
 		// JFormDesigner - Component initialization - DO NOT MODIFY  //GEN-BEGIN:initComponents
@@ -151,12 +177,14 @@ class DataComponentsPanel
 		JScrollPane scrollPane5 = new JScrollPane();
 		table1 = new JTable();
 		JPanel tableOptionsPanel = new JPanel();
+		roundedSelectionCheckBox = new JCheckBox();
 		showHorizontalLinesCheckBox = new JCheckBox();
 		showVerticalLinesCheckBox = new JCheckBox();
 		intercellSpacingCheckBox = new JCheckBox();
 		redGridColorCheckBox = new JCheckBox();
 		rowSelectionCheckBox = new JCheckBox();
 		columnSelectionCheckBox = new JCheckBox();
+		alternatingRowsCheckBox = new JCheckBox();
 		dndCheckBox = new JCheckBox();
 		JPopupMenu popupMenu2 = new JPopupMenu();
 		JMenuItem menuItem3 = new JMenuItem();
@@ -403,44 +431,56 @@ class DataComponentsPanel
 				"[]0" +
 				"[]0" +
 				"[]0" +
+				"[]0" +
+				"[]0" +
 				"[]0"));
 
+			//---- roundedSelectionCheckBox ----
+			roundedSelectionCheckBox.setText("rounded selection");
+			roundedSelectionCheckBox.addActionListener(e -> roundedSelectionChanged());
+			tableOptionsPanel.add(roundedSelectionCheckBox, "cell 0 0");
+
 			//---- showHorizontalLinesCheckBox ----
 			showHorizontalLinesCheckBox.setText("show horizontal lines");
 			showHorizontalLinesCheckBox.addActionListener(e -> showHorizontalLinesChanged());
-			tableOptionsPanel.add(showHorizontalLinesCheckBox, "cell 0 0");
+			tableOptionsPanel.add(showHorizontalLinesCheckBox, "cell 0 1");
 
 			//---- showVerticalLinesCheckBox ----
 			showVerticalLinesCheckBox.setText("show vertical lines");
 			showVerticalLinesCheckBox.addActionListener(e -> showVerticalLinesChanged());
-			tableOptionsPanel.add(showVerticalLinesCheckBox, "cell 0 1");
+			tableOptionsPanel.add(showVerticalLinesCheckBox, "cell 0 2");
 
 			//---- intercellSpacingCheckBox ----
 			intercellSpacingCheckBox.setText("intercell spacing");
 			intercellSpacingCheckBox.addActionListener(e -> intercellSpacingChanged());
-			tableOptionsPanel.add(intercellSpacingCheckBox, "cell 0 2");
+			tableOptionsPanel.add(intercellSpacingCheckBox, "cell 0 3");
 
 			//---- redGridColorCheckBox ----
 			redGridColorCheckBox.setText("red grid color");
 			redGridColorCheckBox.addActionListener(e -> redGridColorChanged());
-			tableOptionsPanel.add(redGridColorCheckBox, "cell 0 3");
+			tableOptionsPanel.add(redGridColorCheckBox, "cell 0 4");
 
 			//---- rowSelectionCheckBox ----
 			rowSelectionCheckBox.setText("row selection");
 			rowSelectionCheckBox.setSelected(true);
 			rowSelectionCheckBox.addActionListener(e -> rowSelectionChanged());
-			tableOptionsPanel.add(rowSelectionCheckBox, "cell 0 4");
+			tableOptionsPanel.add(rowSelectionCheckBox, "cell 0 5");
 
 			//---- columnSelectionCheckBox ----
 			columnSelectionCheckBox.setText("column selection");
 			columnSelectionCheckBox.addActionListener(e -> columnSelectionChanged());
-			tableOptionsPanel.add(columnSelectionCheckBox, "cell 0 5");
+			tableOptionsPanel.add(columnSelectionCheckBox, "cell 0 6");
+
+			//---- alternatingRowsCheckBox ----
+			alternatingRowsCheckBox.setText("alternating rows");
+			alternatingRowsCheckBox.addActionListener(e -> alternatingRowsChanged());
+			tableOptionsPanel.add(alternatingRowsCheckBox, "cell 0 7");
 
 			//---- dndCheckBox ----
 			dndCheckBox.setText("enable drag and drop");
 			dndCheckBox.setMnemonic('D');
 			dndCheckBox.addActionListener(e -> dndChanged());
-			tableOptionsPanel.add(dndCheckBox, "cell 0 6");
+			tableOptionsPanel.add(dndCheckBox, "cell 0 8");
 		}
 		add(tableOptionsPanel, "cell 4 3");
 
@@ -477,12 +517,14 @@ class DataComponentsPanel
 	private JTree tree3;
 	private JTree tree2;
 	private JTable table1;
+	private JCheckBox roundedSelectionCheckBox;
 	private JCheckBox showHorizontalLinesCheckBox;
 	private JCheckBox showVerticalLinesCheckBox;
 	private JCheckBox intercellSpacingCheckBox;
 	private JCheckBox redGridColorCheckBox;
 	private JCheckBox rowSelectionCheckBox;
 	private JCheckBox columnSelectionCheckBox;
+	private JCheckBox alternatingRowsCheckBox;
 	private JCheckBox dndCheckBox;
 	// JFormDesigner - End of variables declaration  //GEN-END:variables
 

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DataComponentsPanel.jfd

@@ -343,9 +343,19 @@ new FormModel {
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 				"$layoutConstraints": "insets 0,hidemode 3"
 				"$columnConstraints": "[]"
-				"$rowConstraints": "[]0[]0[]0[]0[]0[]0[]0"
+				"$rowConstraints": "[]0[]0[]0[]0[]0[]0[]0[]0[]0"
 			} ) {
 				name: "tableOptionsPanel"
+				add( new FormComponent( "javax.swing.JCheckBox" ) {
+					name: "roundedSelectionCheckBox"
+					"text": "rounded selection"
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "roundedSelectionChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 0"
+				} )
 				add( new FormComponent( "javax.swing.JCheckBox" ) {
 					name: "showHorizontalLinesCheckBox"
 					"text": "show horizontal lines"
@@ -354,7 +364,7 @@ new FormModel {
 					}
 					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "showHorizontalLinesChanged", false ) )
 				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
-					"value": "cell 0 0"
+					"value": "cell 0 1"
 				} )
 				add( new FormComponent( "javax.swing.JCheckBox" ) {
 					name: "showVerticalLinesCheckBox"
@@ -364,7 +374,7 @@ new FormModel {
 					}
 					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "showVerticalLinesChanged", false ) )
 				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
-					"value": "cell 0 1"
+					"value": "cell 0 2"
 				} )
 				add( new FormComponent( "javax.swing.JCheckBox" ) {
 					name: "intercellSpacingCheckBox"
@@ -374,7 +384,7 @@ new FormModel {
 					}
 					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "intercellSpacingChanged", false ) )
 				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
-					"value": "cell 0 2"
+					"value": "cell 0 3"
 				} )
 				add( new FormComponent( "javax.swing.JCheckBox" ) {
 					name: "redGridColorCheckBox"
@@ -384,7 +394,7 @@ new FormModel {
 					}
 					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "redGridColorChanged", false ) )
 				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
-					"value": "cell 0 3"
+					"value": "cell 0 4"
 				} )
 				add( new FormComponent( "javax.swing.JCheckBox" ) {
 					name: "rowSelectionCheckBox"
@@ -395,7 +405,7 @@ new FormModel {
 					}
 					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "rowSelectionChanged", false ) )
 				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
-					"value": "cell 0 4"
+					"value": "cell 0 5"
 				} )
 				add( new FormComponent( "javax.swing.JCheckBox" ) {
 					name: "columnSelectionCheckBox"
@@ -405,7 +415,17 @@ new FormModel {
 					}
 					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "columnSelectionChanged", false ) )
 				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
-					"value": "cell 0 5"
+					"value": "cell 0 6"
+				} )
+				add( new FormComponent( "javax.swing.JCheckBox" ) {
+					name: "alternatingRowsCheckBox"
+					"text": "alternating rows"
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "alternatingRowsChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 7"
 				} )
 				add( new FormComponent( "javax.swing.JCheckBox" ) {
 					name: "dndCheckBox"
@@ -416,7 +436,7 @@ new FormModel {
 					}
 					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "dndChanged", false ) )
 				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
-					"value": "cell 0 6"
+					"value": "cell 0 8"
 				} )
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 4 3"

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DemoFrame.java

@@ -73,6 +73,7 @@ class DemoFrame
 		initComponents();
 		updateFontMenuItems();
 		initAccentColors();
+		initFullWindowContent();
 		controlBar.initialize( this, tabbedPane );
 
 		setIconImages( FlatSVGUtils.createWindowIconImages( "/com/formdev/flatlaf/demo/FlatLaf.svg" ) );
@@ -89,24 +90,23 @@ class DemoFrame
 			// do not use HTML text in menu items because this is not supported in macOS screen menu
 			htmlMenuItem.setText( "some text" );
 
+			JRootPane rootPane = getRootPane();
 			if( SystemInfo.isMacFullWindowContentSupported ) {
 				// expand window content into window title bar and make title bar transparent
-				getRootPane().putClientProperty( "apple.awt.fullWindowContent", true );
-				getRootPane().putClientProperty( "apple.awt.transparentTitleBar", true );
+				rootPane.putClientProperty( "apple.awt.fullWindowContent", true );
+				rootPane.putClientProperty( "apple.awt.transparentTitleBar", true );
+				rootPane.putClientProperty( FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING, FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING_LARGE );
 
 				// hide window title
 				if( SystemInfo.isJava_17_orLater )
-					getRootPane().putClientProperty( "apple.awt.windowTitleVisible", false );
+					rootPane.putClientProperty( "apple.awt.windowTitleVisible", false );
 				else
 					setTitle( null );
-
-				// add gap to left side of toolbar
-				toolBar.add( Box.createHorizontalStrut( 70 ), 0 );
 			}
 
 			// enable full screen mode for this window (for Java 8 - 10; not necessary for Java 11+)
 			if( !SystemInfo.isJava_11_orLater )
-				getRootPane().putClientProperty( "apple.awt.fullscreenable", true );
+				rootPane.putClientProperty( "apple.awt.fullscreenable", true );
 		}
 
 		// integrate into macOS screen menu
@@ -461,9 +461,37 @@ class DemoFrame
 			accentColorButtons[i].setVisible( isAccentColorSupported );
 	}
 
+	private void initFullWindowContent() {
+		if( !supportsFlatLafWindowDecorations() )
+			return;
+
+		// create fullWindowContent mode toggle button
+		Icon expandIcon = new FlatSVGIcon( "com/formdev/flatlaf/demo/icons/expand.svg" );
+		Icon collapseIcon = new FlatSVGIcon( "com/formdev/flatlaf/demo/icons/collapse.svg" );
+		JToggleButton fullWindowContentButton = new JToggleButton( expandIcon );
+		fullWindowContentButton.setToolTipText( "Toggle full window content" );
+		fullWindowContentButton.addActionListener( e -> {
+			boolean fullWindowContent = fullWindowContentButton.isSelected();
+			fullWindowContentButton.setIcon( fullWindowContent ? collapseIcon : expandIcon );
+			menuBar.setVisible( !fullWindowContent );
+			toolBar.setVisible( !fullWindowContent );
+			getRootPane().putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT, fullWindowContent );
+		} );
+
+		// add fullWindowContent mode toggle button to tabbed pane
+		JToolBar trailingToolBar = new JToolBar();
+		trailingToolBar.add( Box.createGlue() );
+		trailingToolBar.add( fullWindowContentButton );
+		tabbedPane.putClientProperty( FlatClientProperties.TABBED_PANE_TRAILING_COMPONENT, trailingToolBar );
+	}
+
+	private boolean supportsFlatLafWindowDecorations() {
+		return FlatLaf.supportsNativeWindowDecorations() || (SystemInfo.isLinux && JFrame.isDefaultLookAndFeelDecorated());
+	}
+
 	private void initComponents() {
 		// JFormDesigner - Component initialization - DO NOT MODIFY  //GEN-BEGIN:initComponents
-		JMenuBar menuBar1 = new JMenuBar();
+		menuBar = new JMenuBar();
 		JMenu fileMenu = new JMenu();
 		JMenuItem newMenuItem = new JMenuItem();
 		JMenuItem openMenuItem = new JMenuItem();
@@ -509,6 +537,8 @@ class DemoFrame
 		JMenuItem showUIDefaultsInspectorMenuItem = new JMenuItem();
 		JMenu helpMenu = new JMenu();
 		aboutMenuItem = new JMenuItem();
+		JPanel toolBarPanel = new JPanel();
+		JPanel macFullWindowContentButtonsPlaceholder = new JPanel();
 		toolBar = new JToolBar();
 		JButton backButton = new JButton();
 		JButton forwardButton = new JButton();
@@ -524,8 +554,10 @@ class DemoFrame
 		DataComponentsPanel dataComponentsPanel = new DataComponentsPanel();
 		TabsPanel tabsPanel = new TabsPanel();
 		OptionPanePanel optionPanePanel = new OptionPanePanel();
-		ExtrasPanel extrasPanel1 = new ExtrasPanel();
+		ExtrasPanel extrasPanel = new ExtrasPanel();
 		controlBar = new ControlBar();
+		JPanel themesPanelPanel = new JPanel();
+		JPanel winFullWindowContentButtonsPlaceholder = new JPanel();
 		themesPanel = new IJThemesPanel();
 
 		//======== this ========
@@ -534,7 +566,7 @@ class DemoFrame
 		Container contentPane = getContentPane();
 		contentPane.setLayout(new BorderLayout());
 
-		//======== menuBar1 ========
+		//======== menuBar ========
 		{
 
 			//======== fileMenu ========
@@ -579,7 +611,7 @@ class DemoFrame
 				exitMenuItem.addActionListener(e -> exitActionPerformed());
 				fileMenu.add(exitMenuItem);
 			}
-			menuBar1.add(fileMenu);
+			menuBar.add(fileMenu);
 
 			//======== editMenu ========
 			{
@@ -632,7 +664,7 @@ class DemoFrame
 				deleteMenuItem.addActionListener(e -> menuItemActionPerformed(e));
 				editMenu.add(deleteMenuItem);
 			}
-			menuBar1.add(editMenu);
+			menuBar.add(editMenu);
 
 			//======== viewMenu ========
 			{
@@ -732,7 +764,7 @@ class DemoFrame
 				radioButtonMenuItem3.addActionListener(e -> menuItemActionPerformed(e));
 				viewMenu.add(radioButtonMenuItem3);
 			}
-			menuBar1.add(viewMenu);
+			menuBar.add(viewMenu);
 
 			//======== fontMenu ========
 			{
@@ -756,7 +788,7 @@ class DemoFrame
 				decrFontMenuItem.addActionListener(e -> decrFont());
 				fontMenu.add(decrFontMenuItem);
 			}
-			menuBar1.add(fontMenu);
+			menuBar.add(fontMenu);
 
 			//======== optionsMenu ========
 			{
@@ -808,7 +840,7 @@ class DemoFrame
 				showUIDefaultsInspectorMenuItem.addActionListener(e -> showUIDefaultsInspector());
 				optionsMenu.add(showUIDefaultsInspectorMenuItem);
 			}
-			menuBar1.add(optionsMenu);
+			menuBar.add(optionsMenu);
 
 			//======== helpMenu ========
 			{
@@ -821,54 +853,66 @@ class DemoFrame
 				aboutMenuItem.addActionListener(e -> aboutActionPerformed());
 				helpMenu.add(aboutMenuItem);
 			}
-			menuBar1.add(helpMenu);
+			menuBar.add(helpMenu);
 		}
-		setJMenuBar(menuBar1);
+		setJMenuBar(menuBar);
 
-		//======== toolBar ========
+		//======== toolBarPanel ========
 		{
-			toolBar.setMargin(new Insets(3, 3, 3, 3));
+			toolBarPanel.setLayout(new BorderLayout());
 
-			//---- backButton ----
-			backButton.setToolTipText("Back");
-			backButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/back.svg"));
-			toolBar.add(backButton);
+			//======== macFullWindowContentButtonsPlaceholder ========
+			{
+				macFullWindowContentButtonsPlaceholder.setLayout(new FlowLayout());
+			}
+			toolBarPanel.add(macFullWindowContentButtonsPlaceholder, BorderLayout.WEST);
 
-			//---- forwardButton ----
-			forwardButton.setToolTipText("Forward");
-			forwardButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/forward.svg"));
-			toolBar.add(forwardButton);
-			toolBar.addSeparator();
+			//======== toolBar ========
+			{
+				toolBar.setMargin(new Insets(3, 3, 3, 3));
 
-			//---- cutButton ----
-			cutButton.setToolTipText("Cut");
-			cutButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/menu-cut.svg"));
-			toolBar.add(cutButton);
+				//---- backButton ----
+				backButton.setToolTipText("Back");
+				backButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/back.svg"));
+				toolBar.add(backButton);
 
-			//---- copyButton ----
-			copyButton.setToolTipText("Copy");
-			copyButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/copy.svg"));
-			toolBar.add(copyButton);
+				//---- forwardButton ----
+				forwardButton.setToolTipText("Forward");
+				forwardButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/forward.svg"));
+				toolBar.add(forwardButton);
+				toolBar.addSeparator();
 
-			//---- pasteButton ----
-			pasteButton.setToolTipText("Paste");
-			pasteButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/menu-paste.svg"));
-			toolBar.add(pasteButton);
-			toolBar.addSeparator();
+				//---- cutButton ----
+				cutButton.setToolTipText("Cut");
+				cutButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/menu-cut.svg"));
+				toolBar.add(cutButton);
 
-			//---- refreshButton ----
-			refreshButton.setToolTipText("Refresh");
-			refreshButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/refresh.svg"));
-			toolBar.add(refreshButton);
-			toolBar.addSeparator();
+				//---- copyButton ----
+				copyButton.setToolTipText("Copy");
+				copyButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/copy.svg"));
+				toolBar.add(copyButton);
 
-			//---- showToggleButton ----
-			showToggleButton.setSelected(true);
-			showToggleButton.setToolTipText("Show Details");
-			showToggleButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/show.svg"));
-			toolBar.add(showToggleButton);
+				//---- pasteButton ----
+				pasteButton.setToolTipText("Paste");
+				pasteButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/menu-paste.svg"));
+				toolBar.add(pasteButton);
+				toolBar.addSeparator();
+
+				//---- refreshButton ----
+				refreshButton.setToolTipText("Refresh");
+				refreshButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/refresh.svg"));
+				toolBar.add(refreshButton);
+				toolBar.addSeparator();
+
+				//---- showToggleButton ----
+				showToggleButton.setSelected(true);
+				showToggleButton.setToolTipText("Show Details");
+				showToggleButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/show.svg"));
+				toolBar.add(showToggleButton);
+			}
+			toolBarPanel.add(toolBar, BorderLayout.CENTER);
 		}
-		contentPane.add(toolBar, BorderLayout.NORTH);
+		contentPane.add(toolBarPanel, BorderLayout.PAGE_START);
 
 		//======== contentPanel ========
 		{
@@ -888,13 +932,25 @@ class DemoFrame
 				tabbedPane.addTab("Data Components", dataComponentsPanel);
 				tabbedPane.addTab("Tabs", tabsPanel);
 				tabbedPane.addTab("Option Pane", optionPanePanel);
-				tabbedPane.addTab("Extras", extrasPanel1);
+				tabbedPane.addTab("Extras", extrasPanel);
 			}
 			contentPanel.add(tabbedPane, "cell 0 0");
 		}
 		contentPane.add(contentPanel, BorderLayout.CENTER);
-		contentPane.add(controlBar, BorderLayout.SOUTH);
-		contentPane.add(themesPanel, BorderLayout.EAST);
+		contentPane.add(controlBar, BorderLayout.PAGE_END);
+
+		//======== themesPanelPanel ========
+		{
+			themesPanelPanel.setLayout(new BorderLayout());
+
+			//======== winFullWindowContentButtonsPlaceholder ========
+			{
+				winFullWindowContentButtonsPlaceholder.setLayout(new FlowLayout());
+			}
+			themesPanelPanel.add(winFullWindowContentButtonsPlaceholder, BorderLayout.NORTH);
+			themesPanelPanel.add(themesPanel, BorderLayout.CENTER);
+		}
+		contentPane.add(themesPanelPanel, BorderLayout.LINE_END);
 
 		//---- buttonGroup1 ----
 		ButtonGroup buttonGroup1 = new ButtonGroup();
@@ -909,8 +965,8 @@ class DemoFrame
 		usersButton.setButtonType( ButtonType.toolBarButton );
 		usersButton.setFocusable( false );
 		usersButton.addActionListener( e -> JOptionPane.showMessageDialog( null, "Hello User! How are you?", "User", JOptionPane.INFORMATION_MESSAGE ) );
-		menuBar1.add( Box.createGlue() );
-		menuBar1.add( usersButton );
+		menuBar.add( Box.createGlue() );
+		menuBar.add( usersButton );
 
 		cutMenuItem.addActionListener( new DefaultEditorKit.CutAction() );
 		copyMenuItem.addActionListener( new DefaultEditorKit.CopyAction() );
@@ -922,7 +978,7 @@ class DemoFrame
 		for( int i = 1; i <= 100; i++ )
 			scrollingPopupMenu.add( "Item " + i );
 
-		if( FlatLaf.supportsNativeWindowDecorations() || (SystemInfo.isLinux && JFrame.isDefaultLookAndFeelDecorated()) ) {
+		if( supportsFlatLafWindowDecorations() ) {
 			if( SystemInfo.isLinux )
 				unsupported( windowDecorationsCheckBoxMenuItem );
 			else
@@ -943,6 +999,17 @@ class DemoFrame
 		if( "false".equals( System.getProperty( "flatlaf.animatedLafChange" ) ) )
 			animatedLafChangeMenuItem.setSelected( false );
 
+
+		// on macOS, panel left to toolBar is a placeholder for title bar buttons in fullWindowContent mode
+		macFullWindowContentButtonsPlaceholder.putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER, "mac zeroInFullScreen" );
+
+		// on Windows/Linux, panel above themesPanel is a placeholder for title bar buttons in fullWindowContent mode
+		winFullWindowContentButtonsPlaceholder.putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER, "win" );
+
+		// uncomment this line to see title bar buttons placeholders in fullWindowContent mode
+//		UIManager.put( "FlatLaf.debug.panel.showPlaceholders", true );
+
+
 		// remove contentPanel bottom insets
 		MigLayout layout = (MigLayout) contentPanel.getLayout();
 		LC lc = ConstraintParser.parseLayoutConstraint( (String) layout.getLayoutConstraints() );
@@ -963,6 +1030,7 @@ class DemoFrame
 	}
 
 	// JFormDesigner - Variables declaration - DO NOT MODIFY  //GEN-BEGIN:variables
+	private JMenuBar menuBar;
 	private JMenuItem exitMenuItem;
 	private JMenu scrollingPopupMenu;
 	private JMenuItem htmlMenuItem;

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DemoFrame.jfd

@@ -1,4 +1,4 @@
-JFDML JFormDesigner: "8.1.0.0.283" Java: "19.0.2" encoding: "UTF-8"
+JFDML JFormDesigner: "8.2.1.0.348" Java: "21.0.1" encoding: "UTF-8"
 
 new FormModel {
 	contentType: "form/swing"
@@ -12,59 +12,69 @@ new FormModel {
 			"defaultCloseOperation": 2
 			"$locationPolicy": 2
 			"$sizePolicy": 2
-			add( new FormContainer( "javax.swing.JToolBar", new FormLayoutManager( class javax.swing.JToolBar ) ) {
-				name: "toolBar"
-				"margin": new java.awt.Insets( 3, 3, 3, 3 )
-				auxiliary() {
-					"JavaCodeGenerator.variableLocal": false
-				}
-				add( new FormComponent( "javax.swing.JButton" ) {
-					name: "backButton"
-					"toolTipText": "Back"
-					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/back.svg" )
+			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class java.awt.BorderLayout ) ) {
+				name: "toolBarPanel"
+				add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class java.awt.FlowLayout ) ) {
+					name: "macFullWindowContentButtonsPlaceholder"
+				}, new FormLayoutConstraints( class java.lang.String ) {
+					"value": "West"
 				} )
-				add( new FormComponent( "javax.swing.JButton" ) {
-					name: "forwardButton"
-					"toolTipText": "Forward"
-					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/forward.svg" )
-				} )
-				add( new FormComponent( "javax.swing.JToolBar$Separator" ) {
-					name: "separator5"
-				} )
-				add( new FormComponent( "javax.swing.JButton" ) {
-					name: "cutButton"
-					"toolTipText": "Cut"
-					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/menu-cut.svg" )
-				} )
-				add( new FormComponent( "javax.swing.JButton" ) {
-					name: "copyButton"
-					"toolTipText": "Copy"
-					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/copy.svg" )
-				} )
-				add( new FormComponent( "javax.swing.JButton" ) {
-					name: "pasteButton"
-					"toolTipText": "Paste"
-					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/menu-paste.svg" )
-				} )
-				add( new FormComponent( "javax.swing.JToolBar$Separator" ) {
-					name: "separator6"
-				} )
-				add( new FormComponent( "javax.swing.JButton" ) {
-					name: "refreshButton"
-					"toolTipText": "Refresh"
-					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/refresh.svg" )
-				} )
-				add( new FormComponent( "javax.swing.JToolBar$Separator" ) {
-					name: "separator7"
-				} )
-				add( new FormComponent( "javax.swing.JToggleButton" ) {
-					name: "showToggleButton"
-					"selected": true
-					"toolTipText": "Show Details"
-					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/show.svg" )
+				add( new FormContainer( "javax.swing.JToolBar", new FormLayoutManager( class javax.swing.JToolBar ) ) {
+					name: "toolBar"
+					"margin": new java.awt.Insets( 3, 3, 3, 3 )
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					add( new FormComponent( "javax.swing.JButton" ) {
+						name: "backButton"
+						"toolTipText": "Back"
+						"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/back.svg" )
+					} )
+					add( new FormComponent( "javax.swing.JButton" ) {
+						name: "forwardButton"
+						"toolTipText": "Forward"
+						"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/forward.svg" )
+					} )
+					add( new FormComponent( "javax.swing.JToolBar$Separator" ) {
+						name: "separator5"
+					} )
+					add( new FormComponent( "javax.swing.JButton" ) {
+						name: "cutButton"
+						"toolTipText": "Cut"
+						"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/menu-cut.svg" )
+					} )
+					add( new FormComponent( "javax.swing.JButton" ) {
+						name: "copyButton"
+						"toolTipText": "Copy"
+						"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/copy.svg" )
+					} )
+					add( new FormComponent( "javax.swing.JButton" ) {
+						name: "pasteButton"
+						"toolTipText": "Paste"
+						"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/menu-paste.svg" )
+					} )
+					add( new FormComponent( "javax.swing.JToolBar$Separator" ) {
+						name: "separator6"
+					} )
+					add( new FormComponent( "javax.swing.JButton" ) {
+						name: "refreshButton"
+						"toolTipText": "Refresh"
+						"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/refresh.svg" )
+					} )
+					add( new FormComponent( "javax.swing.JToolBar$Separator" ) {
+						name: "separator7"
+					} )
+					add( new FormComponent( "javax.swing.JToggleButton" ) {
+						name: "showToggleButton"
+						"selected": true
+						"toolTipText": "Show Details"
+						"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/show.svg" )
+					} )
+				}, new FormLayoutConstraints( class java.lang.String ) {
+					"value": "Center"
 				} )
 			}, new FormLayoutConstraints( class java.lang.String ) {
-				"value": "North"
+				"value": "First"
 			} )
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 				"$layoutConstraints": "insets dialog,hidemode 3"
@@ -105,7 +115,7 @@ new FormModel {
 						"title": "Option Pane"
 					} )
 					add( new FormComponent( "com.formdev.flatlaf.demo.extras.ExtrasPanel" ) {
-						name: "extrasPanel1"
+						name: "extrasPanel"
 					}, new FormLayoutConstraints( null ) {
 						"title": "Extras"
 					} )
@@ -121,19 +131,32 @@ new FormModel {
 					"JavaCodeGenerator.variableLocal": false
 				}
 			}, new FormLayoutConstraints( class java.lang.String ) {
-				"value": "South"
+				"value": "Last"
 			} )
-			add( new FormComponent( "com.formdev.flatlaf.demo.intellijthemes.IJThemesPanel" ) {
-				name: "themesPanel"
-				auxiliary() {
-					"JavaCodeGenerator.variableLocal": false
-					"JavaCodeGenerator.variableModifiers": 0
-				}
+			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class java.awt.BorderLayout ) ) {
+				name: "themesPanelPanel"
+				add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class java.awt.FlowLayout ) ) {
+					name: "winFullWindowContentButtonsPlaceholder"
+				}, new FormLayoutConstraints( class java.lang.String ) {
+					"value": "North"
+				} )
+				add( new FormComponent( "com.formdev.flatlaf.demo.intellijthemes.IJThemesPanel" ) {
+					name: "themesPanel"
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+						"JavaCodeGenerator.variableModifiers": 0
+					}
+				}, new FormLayoutConstraints( class java.lang.String ) {
+					"value": "Center"
+				} )
 			}, new FormLayoutConstraints( class java.lang.String ) {
-				"value": "East"
+				"value": "After"
 			} )
 			menuBar: new FormContainer( "javax.swing.JMenuBar", new FormLayoutManager( class javax.swing.JMenuBar ) ) {
-				name: "menuBar1"
+				name: "menuBar"
+				auxiliary() {
+					"JavaCodeGenerator.variableLocal": false
+				}
 				add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
 					name: "fileMenu"
 					"text": "File"

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DemoPrefs.java

@@ -19,6 +19,10 @@ package com.formdev.flatlaf.demo;
 import java.io.File;
 import java.io.FileInputStream;
 import java.util.prefs.Preferences;
+import javax.swing.JComponent;
+import javax.swing.JFrame;
+import javax.swing.JOptionPane;
+import javax.swing.KeyStroke;
 import javax.swing.UIManager;
 import com.formdev.flatlaf.FlatLaf;
 import com.formdev.flatlaf.FlatLightLaf;
@@ -27,6 +31,7 @@ import com.formdev.flatlaf.IntelliJTheme;
 import com.formdev.flatlaf.demo.intellijthemes.IJThemesPanel;
 import com.formdev.flatlaf.util.LoggingFacade;
 import com.formdev.flatlaf.util.StringUtils;
+import com.formdev.flatlaf.util.SystemInfo;
 
 /**
  * @author Karl Tauber
@@ -35,6 +40,7 @@ public class DemoPrefs
 {
 	public static final String KEY_LAF = "laf";
 	public static final String KEY_LAF_THEME = "lafTheme";
+	public static final String KEY_SYSTEM_SCALE_FACTOR = "systemScaleFactor";
 
 	public static final String RESOURCE_PREFIX = "res:";
 	public static final String FILE_PREFIX = "file:";
@@ -96,4 +102,66 @@ public class DemoPrefs
 				state.put( KEY_LAF, UIManager.getLookAndFeel().getClass().getName() );
 		} );
 	}
+
+	public static void initSystemScale() {
+		if( System.getProperty( "sun.java2d.uiScale" ) == null ) {
+			String scaleFactor = getState().get( KEY_SYSTEM_SCALE_FACTOR, null );
+			if( scaleFactor != null )
+				System.setProperty( "sun.java2d.uiScale", scaleFactor );
+		}
+	}
+
+	/**
+	 * register Alt+Shift+F1, F2, ... F12 keys to change system scale factor
+	 */
+	public static void registerSystemScaleFactors( JFrame frame ) {
+		registerSystemScaleFactor( frame, "alt shift F1", null );
+		registerSystemScaleFactor( frame, "alt shift F2", "1" );
+
+		if( SystemInfo.isWindows ) {
+			registerSystemScaleFactor( frame, "alt shift F3", "1.25" );
+			registerSystemScaleFactor( frame, "alt shift F4", "1.5" );
+			registerSystemScaleFactor( frame, "alt shift F5", "1.75" );
+			registerSystemScaleFactor( frame, "alt shift F6", "2" );
+			registerSystemScaleFactor( frame, "alt shift F7", "2.25" );
+			registerSystemScaleFactor( frame, "alt shift F8", "2.5" );
+			registerSystemScaleFactor( frame, "alt shift F9", "2.75" );
+			registerSystemScaleFactor( frame, "alt shift F10", "3" );
+			registerSystemScaleFactor( frame, "alt shift F11", "3.5" );
+			registerSystemScaleFactor( frame, "alt shift F12", "4" );
+		} else {
+			// Java on macOS and Linux supports only integer scale factors
+			registerSystemScaleFactor( frame, "alt shift F3", "2" );
+			registerSystemScaleFactor( frame, "alt shift F4", "3" );
+			registerSystemScaleFactor( frame, "alt shift F5", "4" );
+
+		}
+	}
+
+	private static void registerSystemScaleFactor( JFrame frame, String keyStrokeStr, String scaleFactor ) {
+		KeyStroke keyStroke = KeyStroke.getKeyStroke( keyStrokeStr );
+		if( keyStroke == null )
+			throw new IllegalArgumentException( "Invalid key stroke '" + keyStrokeStr + "'" );
+
+		((JComponent)frame.getContentPane()).registerKeyboardAction(
+			e -> applySystemScaleFactor( frame, scaleFactor ),
+			keyStroke,
+			JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT );
+	}
+
+	private static void applySystemScaleFactor( JFrame frame, String scaleFactor ) {
+		if( JOptionPane.showConfirmDialog( frame,
+				"Change system scale factor to "
+				+ (scaleFactor != null ? scaleFactor : "default")
+				+ " and exit?",
+				frame.getTitle(), JOptionPane.YES_NO_OPTION ) != JOptionPane.YES_OPTION )
+			return;
+
+		if( scaleFactor != null )
+			DemoPrefs.getState().put( KEY_SYSTEM_SCALE_FACTOR, scaleFactor );
+		else
+			DemoPrefs.getState().remove( KEY_SYSTEM_SCALE_FACTOR );
+
+		System.exit( 0 );
+	}
 }

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/FlatLafDemo.java

@@ -70,9 +70,10 @@ public class FlatLafDemo
 		if( FlatLafDemo.screenshotsMode && !SystemInfo.isJava_9_orLater && System.getProperty( "flatlaf.uiScale" ) == null )
 			System.setProperty( "flatlaf.uiScale", "2x" );
 
-		SwingUtilities.invokeLater( () -> {
-			DemoPrefs.init( PREFS_ROOT_PATH );
+		DemoPrefs.init( PREFS_ROOT_PATH );
+		DemoPrefs.initSystemScale();
 
+		SwingUtilities.invokeLater( () -> {
 			// install fonts for lazy loading
 			FlatInterFont.installLazy();
 			FlatJetBrainsMonoFont.installLazy();
@@ -95,6 +96,9 @@ public class FlatLafDemo
 			// use Roboto Mono font
 //			FlatLaf.setPreferredMonospacedFontFamily( FlatRobotoMonoFont.FAMILY );
 
+			// install own repaint manager to fix repaint issues at 125%, 175%, 225%, ... on Windows
+//			HiDPIUtils.installHiDPIRepaintManager();
+
 			// application specific UI defaults
 			FlatLaf.registerCustomDefaultsSource( "com.formdev.flatlaf.demo" );
 

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/MoreComponentsPanel.java

@@ -118,6 +118,14 @@ class MoreComponentsPanel
 		JLabel label5 = new JLabel();
 		JPanel panel13 = new JPanel();
 		JLabel label6 = new JLabel();
+		JLabel panelLabel = new JLabel();
+		JPanel panel5 = new JPanel();
+		JLabel label9 = new JLabel();
+		JPanel panel4 = new JPanel();
+		JLabel label8 = new JLabel();
+		JLabel labelLabel = new JLabel();
+		JLabel label13 = new JLabel();
+		JLabel label10 = new JLabel();
 
 		//======== this ========
 		setLayout(new MigLayout(
@@ -140,7 +148,9 @@ class MoreComponentsPanel
 			"[]" +
 			"[]" +
 			"[]" +
-			"[100,top]"));
+			"[100,top]" +
+			"[50,top]" +
+			"[]"));
 
 		//---- scrollPaneLabel ----
 		scrollPaneLabel.setText("JScrollPane:");
@@ -441,7 +451,7 @@ class MoreComponentsPanel
 
 				//======== panel10 ========
 				{
-					panel10.setBackground(new Color(217, 163, 67));
+					panel10.setBackground(new Color(0xd9a343));
 					panel10.setLayout(new BorderLayout());
 
 					//---- label1 ----
@@ -454,7 +464,7 @@ class MoreComponentsPanel
 
 				//======== panel11 ========
 				{
-					panel11.setBackground(new Color(98, 181, 67));
+					panel11.setBackground(new Color(0x62b543));
 					panel11.setLayout(new BorderLayout());
 
 					//---- label2 ----
@@ -474,7 +484,7 @@ class MoreComponentsPanel
 
 				//======== panel12 ========
 				{
-					panel12.setBackground(new Color(242, 101, 34));
+					panel12.setBackground(new Color(0xf26522));
 					panel12.setLayout(new BorderLayout());
 
 					//---- label5 ----
@@ -487,7 +497,7 @@ class MoreComponentsPanel
 
 				//======== panel13 ========
 				{
-					panel13.setBackground(new Color(64, 182, 224));
+					panel13.setBackground(new Color(0x40b6e0));
 					panel13.setLayout(new BorderLayout());
 
 					//---- label6 ----
@@ -502,6 +512,52 @@ class MoreComponentsPanel
 		}
 		add(splitPane3, "cell 1 11 4 1,grow");
 
+		//---- panelLabel ----
+		panelLabel.setText("JPanel:");
+		add(panelLabel, "cell 0 12");
+
+		//======== panel5 ========
+		{
+			panel5.putClientProperty("FlatLaf.style", "arc: 16; background: darken($Panel.background,5%)");
+			panel5.setLayout(new BorderLayout());
+
+			//---- label9 ----
+			label9.setText("rounded background");
+			label9.setHorizontalAlignment(SwingConstants.CENTER);
+			panel5.add(label9, BorderLayout.CENTER);
+		}
+		add(panel5, "cell 1 12 4 1,growy,width 150");
+
+		//======== panel4 ========
+		{
+			panel4.putClientProperty("FlatLaf.style", "border: 1,1,1,1,@disabledForeground,1,16; background: darken($Panel.background,5%)");
+			panel4.setLayout(new BorderLayout());
+
+			//---- label8 ----
+			label8.setText("rounded border");
+			label8.setHorizontalAlignment(SwingConstants.CENTER);
+			panel4.add(label8, BorderLayout.CENTER);
+		}
+		add(panel4, "cell 1 12 4 1,growy,width 150");
+
+		//---- labelLabel ----
+		labelLabel.setText("JLabel:");
+		add(labelLabel, "cell 0 13");
+
+		//---- label13 ----
+		label13.setText("rounded background");
+		label13.putClientProperty("FlatLaf.style", "arc: 999; border: 2,10,2,10");
+		label13.setBackground(new Color(0xb8e4f3));
+		label13.setForeground(new Color(0x135b76));
+		add(label13, "cell 1 13 4 1");
+
+		//---- label10 ----
+		label10.setText("rounded border");
+		label10.putClientProperty("FlatLaf.style", "arc: 999; border: 2,10,2,10,#135b76");
+		label10.setBackground(new Color(0xb8e4f3));
+		label10.setForeground(new Color(0x135b76));
+		add(label10, "cell 1 13 4 1");
+
 		//---- buttonGroup1 ----
 		ButtonGroup buttonGroup1 = new ButtonGroup();
 		buttonGroup1.add(toggleButton1);

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/MoreComponentsPanel.jfd

@@ -1,4 +1,4 @@
-JFDML JFormDesigner: "7.0.5.0.404" Java: "17.0.2" encoding: "UTF-8"
+JFDML JFormDesigner: "8.2.2.0.9999" Java: "21.0.1" encoding: "UTF-8"
 
 new FormModel {
 	contentType: "form/swing"
@@ -9,7 +9,7 @@ new FormModel {
 		add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 			"$layoutConstraints": "insets dialog,hidemode 3"
 			"$columnConstraints": "[][][][][]"
-			"$rowConstraints": "[][][][][][][][][][][][100,top]"
+			"$rowConstraints": "[][][][][][][][][][][][100,top][50,top][]"
 		} ) {
 			name: "this"
 			add( new FormComponent( "javax.swing.JLabel" ) {
@@ -467,6 +467,62 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 1 11 4 1,grow"
 			} )
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "panelLabel"
+				"text": "JPanel:"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 12"
+			} )
+			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class java.awt.BorderLayout ) ) {
+				name: "panel5"
+				"$client.FlatLaf.style": "arc: 16; background: darken($Panel.background,5%)"
+				add( new FormComponent( "javax.swing.JLabel" ) {
+					name: "label9"
+					"text": "rounded background"
+					"horizontalAlignment": 0
+				}, new FormLayoutConstraints( class java.lang.String ) {
+					"value": "Center"
+				} )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 12 4 1,growy,width 150"
+			} )
+			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class java.awt.BorderLayout ) ) {
+				name: "panel4"
+				"$client.FlatLaf.style": "border: 1,1,1,1,@disabledForeground,1,16; background: darken($Panel.background,5%)"
+				add( new FormComponent( "javax.swing.JLabel" ) {
+					name: "label8"
+					"text": "rounded border"
+					"horizontalAlignment": 0
+				}, new FormLayoutConstraints( class java.lang.String ) {
+					"value": "Center"
+				} )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 12 4 1,growy,width 150"
+			} )
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "labelLabel"
+				"text": "JLabel:"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 13"
+			} )
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "label13"
+				"text": "rounded background"
+				"$client.FlatLaf.style": "arc: 999; border: 2,10,2,10"
+				"background": new java.awt.Color( 184, 228, 243, 255 )
+				"foreground": new java.awt.Color( 19, 91, 118, 255 )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 13 4 1"
+			} )
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "label10"
+				"text": "rounded border"
+				"$client.FlatLaf.style": "arc: 999; border: 2,10,2,10,#135b76"
+				"background": new java.awt.Color( 184, 228, 243, 255 )
+				"foreground": new java.awt.Color( 19, 91, 118, 255 )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 13 4 1"
+			} )
 		}, new FormLayoutConstraints( null ) {
 			"location": new java.awt.Point( 0, 0 )
 			"size": new java.awt.Dimension( 700, 550 )
@@ -474,7 +530,7 @@ new FormModel {
 		add( new FormNonVisual( "javax.swing.ButtonGroup" ) {
 			name: "buttonGroup1"
 		}, new FormLayoutConstraints( null ) {
-			"location": new java.awt.Point( 0, 560 )
+			"location": new java.awt.Point( 0, 600 )
 		} )
 	}
 }

flatlaf-demo/src/main/resources/com/formdev/flatlaf/demo/icons/collapse.svg

@@ -0,0 +1,4 @@
+<!-- Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license. -->
+<svg width="16" height="16" viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg">
+<path d="M1.5 14.5L6 10M14.5 1.5L9.99998 6.00001M2.5 9.50001H6.5L6.5 13.5M13.5 6.5L9.5 6.50003V2.5" stroke="#6E6E6E" stroke-linecap="round" stroke-linejoin="round"/>
+</svg>

flatlaf-demo/src/main/resources/com/formdev/flatlaf/demo/icons/expand.svg

@@ -0,0 +1,4 @@
+<!-- Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license. -->
+<svg width="16" height="16" viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg">
+<path d="M6.5 9.5L2 14M9.50003 6.50004L14 2.00001M5.5 14.5H1.5V10.5M10.5 1.5L14.5 1.50002V5.5" stroke="#6E6E6E" stroke-linecap="round" stroke-linejoin="round"/>
+</svg>