Merge pull request #267 from native-window-decorations

Native window decorations for Windows 10 (using JNI)
2026-02-11 06:27:13 -06:00 · 2021-03-12 23:15:19 +01:00
parent 83e904dd2d 73487ccf65
commit 39d56f2603
36 changed files with 1669 additions and 89 deletions
--- a/.gitattributes
+++ b/.gitattributes
@@ -15,8 +15,11 @@
 # BINARY FILES:
 #   Disable line ending normalize on checkin.

+*.dll binary
+*.dylib binary
 *.gif binary
 *.jar binary
 *.png binary
 *.sketch binary
+*.so binary
 *.zip binary
--- a/.github/workflows/natives.yml
+++ b/.github/workflows/natives.yml
@@ -0,0 +1,56 @@
+# https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-gradle
+
+name: Native Libraries
+
+on:
+    push:
+        branches:
+            - '*'
+        tags:
+            - '[0-9]*'
+        paths:
+            - '**.cpp'
+            - '**.h'
+    pull_request:
+        branches:
+            - '*'
+        paths:
+            - '**.cpp'
+            - '**.h'
+
+jobs:
+    Windows:
+        runs-on: windows-latest
+
+        steps:
+            - uses: actions/checkout@v2
+
+            - uses: gradle/wrapper-validation-action@v1
+
+            - name: Setup Java 1.8
+              uses: actions/setup-java@v1
+              with:
+                  java-version: 1.8
+
+            - name: Cache Gradle wrapper
+              uses: actions/cache@v1
+              with:
+                  path: ~/.gradle/wrapper
+                  key: ${{ runner.os }}-gradle-wrapper-${{ hashFiles('gradle/wrapper/gradle-wrapper.properties') }}
+
+            - name: Cache Gradle cache
+              uses: actions/cache@v2
+              with:
+                  path: ~/.gradle/caches
+                  key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle.kts') }}
+                  restore-keys: ${{ runner.os }}-gradle
+
+            - name: Build with Gradle
+              run: ./gradlew :flatlaf-natives-windows:build
+
+            - name: Upload artifacts
+              uses: actions/upload-artifact@v2
+              with:
+                  name: FlatLaf-natives-windows-build-artifacts
+                  path: |
+                      flatlaf-natives/flatlaf-natives-windows/build
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,5 @@ out/
 *.iml
 *.ipr
 *.iws
+.vs/
+.vscode/
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,13 @@ FlatLaf Change Log

 ## 1.1-SNAPSHOT

+#### New features and improvements
+
+- Native window decorations for Windows 10 enables dark frame/dialog title bar
+  and embedded menu bar with all JREs, while still having native Windows 10
+  border drop shadows, resize behavior, window snapping and system window menu.
+  (PR #267)
+
 #### Fixed bugs

 - IntelliJ Themes: Fixed text color of CheckBoxMenuItem and RadioButtonMenuItem
--- a/flatlaf-core/build.gradle.kts
+++ b/flatlaf-core/build.gradle.kts
@@ -27,6 +27,16 @@ java {
 }

 tasks {
+	compileJava {
+		// generate JNI headers
+		options.headerOutputDirectory.set( buildDir.resolve( "generated/jni-headers" ) )
+	}
+
+	processResources {
+		// build native libraries
+		dependsOn( ":flatlaf-natives-windows:assemble" )
+	}
+
 	jar {
 		archiveBaseName.set( "flatlaf" )

--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/FlatLaf.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/FlatLaf.java
@@ -44,7 +44,6 @@ import javax.swing.ImageIcon;
 import javax.swing.JComponent;
 import javax.swing.JDialog;
 import javax.swing.JFrame;
-import javax.swing.JRootPane;
 import javax.swing.LookAndFeel;
 import javax.swing.PopupFactory;
 import javax.swing.SwingUtilities;
@@ -90,9 +89,6 @@ public abstract class FlatLaf

 	private Consumer<UIDefaults> postInitialization;

-	private Boolean oldFrameWindowDecorated;
-	private Boolean oldDialogWindowDecorated;
-
 	/**
 	 * Sets the application look and feel to the given LaF
 	 * using {@link UIManager#setLookAndFeel(javax.swing.LookAndFeel)}.
@@ -144,35 +140,20 @@ public abstract class FlatLaf
 	 * Returns whether FlatLaf supports custom window decorations.
 	 * This depends on the operating system and on the used Java runtime.
 	 * <p>
-	 * To use custom window decorations in your application, enable them with
-	 * following code (before creating any frames or dialogs).
-	 * <pre>
-	 * JFrame.setDefaultLookAndFeelDecorated( true );
-	 * JDialog.setDefaultLookAndFeelDecorated( true );
-	 * </pre>
-	 * <p>
-	 * Then custom window decorations are only enabled if this method returns {@code true}.
-	 * In this case, when creating a {@link JFrame} or {@link JDialog}, the frame/dialog will be made
-	 * undecorated ({@link JFrame#setUndecorated(boolean)} / {@link JDialog#setUndecorated(boolean)}),
-	 * the window decoration style of the {@link JRootPane} will
-	 * {@link JRootPane#FRAME} / {@link JRootPane#PLAIN_DIALOG}
-	 * (see {@link JRootPane#setWindowDecorationStyle(int)}) and the look and feel
-	 * is responsible for the whole frame/dialog border (including window resizing).
-	 * <p>
 	 * This method returns {@code true} on Windows 10 (see exception below), {@code false} otherwise.
 	 * <p>
 	 * Returns also {@code false} on Windows 10 if:
 	 * <ul>
-	 * <li>FlatLaf native window border support is available (requires {@code flatlaf-natives-jna.jar})</li>
+	 * <li>FlatLaf native window border support is available (requires Windows 10 64-bit)</li>
 	 * <li>running in
 	 * <a href="https://confluence.jetbrains.com/display/JBR/JetBrains+Runtime">JetBrains Runtime 11 (or later)</a>
 	 * (<a href="https://github.com/JetBrains/JetBrainsRuntime">source code on github</a>)
 	 * and JBR supports custom window decorations
 	 * </li>
 	 * </ul>
-	 * In this case, custom decorations are enabled by the root pane
-	 * if {@link JFrame#isDefaultLookAndFeelDecorated()} or
-	 * {@link JDialog#isDefaultLookAndFeelDecorated()} return {@code true}.
+	 * In this cases, custom decorations are enabled by the root pane.
+	 * Usage of {@link JFrame#setDefaultLookAndFeelDecorated(boolean)} or
+	 * {@link JDialog#setDefaultLookAndFeelDecorated(boolean)} is not necessary.
 	 */
 	@Override
 	public boolean getSupportsWindowDecorations() {
@@ -276,16 +257,6 @@ public abstract class FlatLaf
 					String.format( "a, address { color: #%06x; }", linkColor.getRGB() & 0xffffff ) );
 			}
 		};
-
-		// enable/disable window decorations, but only if system property is either
-		// "true" or "false"; in other cases it is not changed
-		Boolean useWindowDecorations = FlatSystemProperties.getBooleanStrict( FlatSystemProperties.USE_WINDOW_DECORATIONS, null );
-		if( useWindowDecorations != null ) {
-			oldFrameWindowDecorated = JFrame.isDefaultLookAndFeelDecorated();
-			oldDialogWindowDecorated = JDialog.isDefaultLookAndFeelDecorated();
-			JFrame.setDefaultLookAndFeelDecorated( useWindowDecorations );
-			JDialog.setDefaultLookAndFeelDecorated( useWindowDecorations );
-		}
 	}

 	@Override
@@ -318,14 +289,6 @@ public abstract class FlatLaf
 		new HTMLEditorKit().getStyleSheet().addRule( "a, address { color: blue; }" );
 		postInitialization = null;

-		// restore enable/disable window decorations
-		if( oldFrameWindowDecorated != null ) {
-			JFrame.setDefaultLookAndFeelDecorated( oldFrameWindowDecorated );
-			JDialog.setDefaultLookAndFeelDecorated( oldDialogWindowDecorated );
-			oldFrameWindowDecorated = null;
-			oldDialogWindowDecorated = null;
-		}
-
 		super.uninitialize();
 	}

--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/FlatSystemProperties.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/FlatSystemProperties.java
@@ -16,9 +16,6 @@

 package com.formdev.flatlaf;

-import javax.swing.JDialog;
-import javax.swing.JFrame;
-
 /**
 * Defines/documents own system properties used in FlatLaf.
 *
@@ -57,38 +54,21 @@ public interface FlatSystemProperties
 	 */
 	String USE_UBUNTU_FONT = "flatlaf.useUbuntuFont";

-	/**
-	 * Specifies whether custom look and feel window decorations should be used
-	 * when creating {@code JFrame} or {@code JDialog}.
-	 * <p>
-	 * If this system property is set, FlatLaf invokes {@link JFrame#setDefaultLookAndFeelDecorated(boolean)}
-	 * and {@link JDialog#setDefaultLookAndFeelDecorated(boolean)} on LaF initialization.
-	 * <p>
-	 * (requires Window 10)
-	 * <p>
-	 * <strong>Allowed Values</strong> {@code false} and {@code true}<br>
-	 * <strong>Default</strong> none
-	 */
-	String USE_WINDOW_DECORATIONS = "flatlaf.useWindowDecorations";
-
 	/**
 	 * Specifies whether FlatLaf native window decorations should be used
 	 * when creating {@code JFrame} or {@code JDialog}.
-	 * Requires that {@code flatlaf-natives-jna.jar} is on classpath/modulepath.
 	 * <p>
 	 * Setting this to {@code true} forces using FlatLaf native window decorations
 	 * even if they are not enabled by the application.
 	 * <p>
 	 * Setting this to {@code false} disables using FlatLaf native window decorations.
 	 * <p>
-	 * (requires Window 10)
+	 * (requires Window 10 64-bit)
 	 * <p>
 	 * <strong>Allowed Values</strong> {@code false} and {@code true}<br>
 	 * <strong>Default</strong> none
-	 *
-	 * @since 1.1
 	 */
-	String USE_NATIVE_WINDOW_DECORATIONS = "flatlaf.useNativeWindowDecorations";
+	String USE_WINDOW_DECORATIONS = "flatlaf.useWindowDecorations";

 	/**
 	 * Specifies whether JetBrains Runtime custom window decorations should be used
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatNativeWindowBorder.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatNativeWindowBorder.java
@@ -20,7 +20,6 @@ import java.awt.Color;
 import java.awt.Rectangle;
 import java.awt.Window;
 import java.beans.PropertyChangeListener;
-import java.lang.reflect.Method;
 import java.util.List;
 import javax.swing.JDialog;
 import javax.swing.JFrame;
@@ -70,7 +69,7 @@ public class FlatNativeWindowBorder
 		// It could be also be a window that is currently hidden, but may be shown later.
 		Window window = SwingUtilities.windowForComponent( rootPane );
 		if( window != null && window.isDisplayable() ) {
-			install( window, FlatSystemProperties.USE_NATIVE_WINDOW_DECORATIONS );
+			install( window, FlatSystemProperties.USE_WINDOW_DECORATIONS );
 			return null;
 		}

@@ -80,7 +79,7 @@ public class FlatNativeWindowBorder
 		PropertyChangeListener ancestorListener = e -> {
 			Object newValue = e.getNewValue();
 			if( newValue instanceof Window )
-				install( (Window) newValue, FlatSystemProperties.USE_NATIVE_WINDOW_DECORATIONS );
+				install( (Window) newValue, FlatSystemProperties.USE_WINDOW_DECORATIONS );
 			else if( newValue == null && e.getOldValue() instanceof Window )
 				uninstall( (Window) e.getOldValue() );
 		};
@@ -102,7 +101,8 @@ public class FlatNativeWindowBorder
 			// do not enable native window border if JFrame should use system window decorations
 			// and if not forced to use FlatLaf/JBR native window decorations
 			if( !JFrame.isDefaultLookAndFeelDecorated() &&
-				!FlatSystemProperties.getBoolean( systemPropertyKey, false ))
+				!UIManager.getBoolean( "TitlePane.useWindowDecorations" ) &&
+				!FlatSystemProperties.getBoolean( systemPropertyKey, false ) )
 			  return;

 			// do not enable native window border if frame is undecorated
@@ -121,7 +121,8 @@ public class FlatNativeWindowBorder
 			// do not enable native window border if JDialog should use system window decorations
 			// and if not forced to use FlatLaf/JBR native window decorations
 			if( !JDialog.isDefaultLookAndFeelDecorated() &&
-				!FlatSystemProperties.getBoolean( systemPropertyKey, false ))
+				!UIManager.getBoolean( "TitlePane.useWindowDecorations" ) &&
+				!FlatSystemProperties.getBoolean( systemPropertyKey, false ) )
 			  return;

 			// do not enable native window border if dialog is undecorated
@@ -224,13 +225,17 @@ public class FlatNativeWindowBorder
 		if( !SystemInfo.isWindows_10_orLater || !SystemInfo.isX86_64 )
 			return;

-		if( !FlatSystemProperties.getBoolean( FlatSystemProperties.USE_NATIVE_WINDOW_DECORATIONS, true ) )
+		// check whether disabled via system property
+		if( !FlatSystemProperties.getBoolean( FlatSystemProperties.USE_WINDOW_DECORATIONS, true ) )
 			return;

 		try {
+/*
 			Class<?> cls = Class.forName( "com.formdev.flatlaf.natives.jna.windows.FlatWindowsNativeWindowBorder" );
 			Method m = cls.getMethod( "getInstance" );
 			nativeProvider = (Provider) m.invoke( null );
+*/
+			nativeProvider = FlatWindowsNativeWindowBorder.getInstance();

 			supported = (nativeProvider != null);
 		} catch( Exception ex ) {
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatWindowsNativeWindowBorder.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatWindowsNativeWindowBorder.java
@@ -0,0 +1,380 @@
+/*
+ * Copyright 2021 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.Dialog;
+import java.awt.EventQueue;
+import java.awt.Frame;
+import java.awt.GraphicsConfiguration;
+import java.awt.Point;
+import java.awt.Rectangle;
+import java.awt.Window;
+import java.awt.geom.AffineTransform;
+import java.util.Collections;
+import java.util.IdentityHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import javax.swing.JDialog;
+import javax.swing.JFrame;
+import javax.swing.Timer;
+import javax.swing.event.ChangeEvent;
+import javax.swing.event.ChangeListener;
+import javax.swing.event.EventListenerList;
+import com.formdev.flatlaf.FlatLaf;
+import com.formdev.flatlaf.util.NativeLibrary;
+import com.formdev.flatlaf.util.SystemInfo;
+
+//
+// Interesting resources:
+//     https://github.com/microsoft/terminal/blob/main/src/cascadia/WindowsTerminal/NonClientIslandWindow.cpp
+//     https://docs.microsoft.com/en-us/windows/win32/dwm/customframe
+//     https://github.com/JetBrains/JetBrainsRuntime/blob/master/src/java.desktop/windows/native/libawt/windows/awt_Frame.cpp
+//     https://github.com/JetBrains/JetBrainsRuntime/commit/d2820524a1aa211b1c49b30f659b9b4d07a6f96e
+//     https://github.com/JetBrains/JetBrainsRuntime/pull/18
+//     https://medium.com/swlh/customizing-the-title-bar-of-an-application-window-50a4ac3ed27e
+//     https://github.com/kalbetredev/CustomDecoratedJFrame
+//     https://github.com/Guerra24/NanoUI-win32
+//     https://github.com/oberth/custom-chrome
+//     https://github.com/rossy/borderless-window
+//
+
+/**
+ * Native window border support for Windows 10 when using custom decorations.
+ * <p>
+ * If the application wants to use custom decorations, the Windows 10 title bar is hidden
+ * (including minimize, maximize and close buttons), but not the resize borders (including drop shadow).
+ * Windows 10 window snapping functionality will remain unaffected:
+ * https://support.microsoft.com/en-us/windows/snap-your-windows-885a9b1e-a983-a3b1-16cd-c531795e6241
+ *
+ * @author Karl Tauber
+ */
+class FlatWindowsNativeWindowBorder
+	implements FlatNativeWindowBorder.Provider
+{
+	private final Map<Window, WndProc> windowsMap = Collections.synchronizedMap( new IdentityHashMap<>() );
+	private final EventListenerList listenerList = new EventListenerList();
+	private Timer fireStateChangedTimer;
+
+	private boolean colorizationUpToDate;
+	private boolean colorizationColorAffectsBorders;
+	private Color colorizationColor;
+	private int colorizationColorBalance;
+
+	private static NativeLibrary nativeLibrary;
+	private static FlatWindowsNativeWindowBorder instance;
+
+	static FlatNativeWindowBorder.Provider getInstance() {
+		// requires Windows 10 on x86_64
+		if( !SystemInfo.isWindows_10_orLater || !SystemInfo.isX86_64 )
+			return null;
+
+		// load native library
+		if( nativeLibrary == null ) {
+			if( !SystemInfo.isJava_9_orLater ) {
+				// In Java 8, load jawt.dll (part of JRE) explicitly because it
+				// is not found when running application with <jdk>/bin/java.exe.
+				// When using <jdk>/jre/bin/java.exe, it is found.
+				// jawt.dll is located in <jdk>/jre/bin/.
+				// Java 9 and later does not have this problem.
+				try {
+					System.loadLibrary( "jawt" );
+				} catch( Exception ex ) {
+					Logger.getLogger( FlatLaf.class.getName() ).log( Level.SEVERE, null, ex );
+				}
+			}
+
+			nativeLibrary = new NativeLibrary(
+				"com/formdev/flatlaf/natives/flatlaf-windows-x86_64",
+				FlatWindowsNativeWindowBorder.class.getClassLoader(), true );
+		}
+
+		// check whether native library was successfully loaded
+		if( !nativeLibrary.isLoaded() )
+			return null;
+
+		// create new instance
+		if( instance == null )
+			instance = new FlatWindowsNativeWindowBorder();
+		return instance;
+	}
+
+	private FlatWindowsNativeWindowBorder() {
+	}
+
+	@Override
+	public boolean hasCustomDecoration( Window window ) {
+		return windowsMap.containsKey( window );
+	}
+
+	/**
+	 * Tell the window whether the application wants use custom decorations.
+	 * If {@code true}, the Windows 10 title bar is hidden (including minimize,
+	 * maximize and close buttons), but not the resize borders (including drop shadow).
+	 */
+	@Override
+	public void setHasCustomDecoration( Window window, boolean hasCustomDecoration ) {
+		if( hasCustomDecoration )
+			install( window );
+		else
+			uninstall( window );
+	}
+
+	private void install( Window window ) {
+		// requires Windows 10 on x86_64
+		if( !SystemInfo.isWindows_10_orLater || !SystemInfo.isX86_64 )
+			return;
+
+		// only JFrame and JDialog are supported
+		if( !(window instanceof JFrame) && !(window instanceof JDialog) )
+			return;
+
+		// not supported if frame/dialog is undecorated
+		if( (window instanceof Frame && ((Frame)window).isUndecorated()) ||
+			(window instanceof Dialog && ((Dialog)window).isUndecorated()) )
+		  return;
+
+		// check whether already installed
+		if( windowsMap.containsKey( window ) )
+			return;
+
+		// install
+		WndProc wndProc = new WndProc( window );
+		if( wndProc.hwnd == 0 )
+			return;
+
+		windowsMap.put( window, wndProc );
+	}
+
+	private void uninstall( Window window ) {
+		WndProc wndProc = windowsMap.remove( window );
+		if( wndProc != null )
+			wndProc.uninstall();
+	}
+
+	@Override
+	public void setTitleBarHeight( Window window, int titleBarHeight ) {
+		WndProc wndProc = windowsMap.get( window );
+		if( wndProc == null )
+			return;
+
+		wndProc.titleBarHeight = titleBarHeight;
+	}
+
+	@Override
+	public void setTitleBarHitTestSpots( Window window, List<Rectangle> hitTestSpots ) {
+		WndProc wndProc = windowsMap.get( window );
+		if( wndProc == null )
+			return;
+
+		wndProc.hitTestSpots = hitTestSpots.toArray( new Rectangle[hitTestSpots.size()] );
+	}
+
+	@Override
+	public void setTitleBarAppIconBounds( Window window, Rectangle appIconBounds ) {
+		WndProc wndProc = windowsMap.get( window );
+		if( wndProc == null )
+			return;
+
+		wndProc.appIconBounds = (appIconBounds != null) ? new Rectangle( appIconBounds ) : null;
+	}
+
+	@Override
+	public boolean isColorizationColorAffectsBorders() {
+		updateColorization();
+		return colorizationColorAffectsBorders;
+	}
+
+	@Override
+	public Color getColorizationColor() {
+		updateColorization();
+		return colorizationColor;
+	}
+
+	@Override
+	public int getColorizationColorBalance() {
+		updateColorization();
+		return colorizationColorBalance;
+	}
+
+	private void updateColorization() {
+		if( colorizationUpToDate )
+			return;
+		colorizationUpToDate = true;
+
+		String subKey = "SOFTWARE\\Microsoft\\Windows\\DWM";
+
+		int value = registryGetIntValue( subKey, "ColorPrevalence", -1 );
+		colorizationColorAffectsBorders = (value > 0);
+
+		value = registryGetIntValue( subKey, "ColorizationColor", -1 );
+		colorizationColor = (value != -1) ? new Color( value ) : null;
+
+		colorizationColorBalance = registryGetIntValue( subKey, "ColorizationColorBalance", -1 );
+	}
+
+	private native static int registryGetIntValue( String key, String valueName, int defaultValue );
+
+	@Override
+	public void addChangeListener( ChangeListener l ) {
+		listenerList.add( ChangeListener.class, l );
+	}
+
+	@Override
+	public void removeChangeListener( ChangeListener l ) {
+		listenerList.remove( ChangeListener.class, l );
+	}
+
+	private void fireStateChanged() {
+		Object[] listeners = listenerList.getListenerList();
+		if( listeners.length == 0 )
+			return;
+
+		ChangeEvent e = new ChangeEvent( this );
+		for( int i = 0; i < listeners.length; i += 2 ) {
+			if( listeners[i] == ChangeListener.class )
+				((ChangeListener)listeners[i+1]).stateChanged( e );
+		}
+	}
+
+	/**
+	 * Because there may be sent many WM_DWMCOLORIZATIONCOLORCHANGED messages,
+	 * slightly delay event firing and fire it only once (on the AWT thread).
+	 */
+	void fireStateChangedLaterOnce() {
+		EventQueue.invokeLater( () -> {
+			if( fireStateChangedTimer != null ) {
+				fireStateChangedTimer.restart();
+				return;
+			}
+
+			fireStateChangedTimer = new Timer( 300, e -> {
+				fireStateChangedTimer = null;
+				colorizationUpToDate = false;
+
+				fireStateChanged();
+			} );
+			fireStateChangedTimer.setRepeats( false );
+			fireStateChangedTimer.start();
+		} );
+	}
+
+	//---- class WndProc ------------------------------------------------------
+
+	private class WndProc
+	{
+		// WM_NCHITTEST mouse position codes
+		private static final int
+			HTCLIENT = 1,
+			HTCAPTION = 2,
+			HTSYSMENU = 3,
+			HTTOP = 12;
+
+		private Window window;
+		private final long hwnd;
+
+		private int titleBarHeight;
+		private Rectangle[] hitTestSpots;
+		private Rectangle appIconBounds;
+
+		WndProc( Window window ) {
+			this.window = window;
+
+			hwnd = installImpl( window );
+		}
+
+		void uninstall() {
+			uninstallImpl( hwnd );
+
+			// cleanup
+			window = null;
+		}
+
+		private native long installImpl( Window window );
+		private native void uninstallImpl( long hwnd );
+
+		// invoked from native code
+		private int onNcHitTest( int x, int y, boolean isOnResizeBorder ) {
+			// scale-down mouse x/y
+			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( appIconBounds != null && appIconBounds.contains( sx, sy ) )
+				return HTSYSMENU;
+
+			boolean isOnTitleBar = (sy < 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;
+				}
+				return isOnResizeBorder ? HTTOP : HTCAPTION;
+			}
+
+			return isOnResizeBorder ? HTTOP : HTCLIENT;
+		}
+
+		/**
+		 * Scales down in the same way as AWT.
+		 * See AwtWin32GraphicsDevice::ScaleDownX() and ::ScaleDownY()
+		 */
+		private Point scaleDown( int x, int y ) {
+			GraphicsConfiguration gc = window.getGraphicsConfiguration();
+			if( gc == null )
+				return new Point( x, y );
+
+			AffineTransform t = gc.getDefaultTransform();
+			return new Point( clipRound( x / t.getScaleX() ), clipRound( y / t.getScaleY() ) );
+		}
+
+		/**
+		 * Rounds in the same way as AWT.
+		 * See AwtWin32GraphicsDevice::ClipRound()
+		 */
+		private int clipRound( double value ) {
+			value -= 0.5;
+			if( value < Integer.MIN_VALUE )
+				return Integer.MIN_VALUE;
+			if( value > Integer.MAX_VALUE )
+				return Integer.MAX_VALUE;
+			return (int) Math.ceil( value );
+		}
+
+		// invoked from native code
+		private boolean isFullscreen() {
+			GraphicsConfiguration gc = window.getGraphicsConfiguration();
+			if( gc == null )
+				return false;
+			return gc.getDevice().getFullScreenWindow() == window;
+		}
+
+		// invoked from native code
+		private void fireStateChangedLaterOnce() {
+			FlatWindowsNativeWindowBorder.this.fireStateChangedLaterOnce();
+		}
+	}
+}
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/JBRCustomDecorations.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/JBRCustomDecorations.java
@@ -165,6 +165,7 @@ public class JBRCustomDecorations
 		if( !SystemInfo.isJetBrainsJVM_11_orLater || !SystemInfo.isWindows_10_orLater )
 			return;

+		// check whether disabled via system property
 		if( !FlatSystemProperties.getBoolean( FlatSystemProperties.USE_JETBRAINS_CUSTOM_DECORATIONS, true ) )
 			return;

--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/util/NativeLibrary.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/util/NativeLibrary.java
@@ -0,0 +1,193 @@
+/*
+ * Copyright 2021 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.util;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.StandardCopyOption;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import com.formdev.flatlaf.FlatLaf;
+
+/**
+ * Helper class to load native library (.dll, .so or .dylib) stored in Jar.
+ * <p>
+ * Copies native library to users temporary folder before loading it.
+ *
+ * @author Karl Tauber
+ */
+public class NativeLibrary
+{
+	private static final String DELETE_SUFFIX = ".delete";
+	private static boolean deletedTemporary;
+
+	private final boolean loaded;
+
+	/**
+	 * Load native library from given classloader.
+	 *
+	 * @param libraryName resource name of the native library (without "lib" prefix and without extension)
+	 * @param classLoader the classloader used to locate the library
+	 * @param supported whether the native library is supported on the current platform
+	 */
+	public NativeLibrary( String libraryName, ClassLoader classLoader, boolean supported ) {
+		this.loaded = supported
+			? loadLibraryFromJar( libraryName, classLoader )
+			: false;
+	}
+
+	/**
+	 * Returns whether the native library is loaded.
+	 * <p>
+	 * Returns {@code false} if not supported on current platform as specified in constructor
+	 * or if loading failed.
+	 */
+	public boolean isLoaded() {
+		return loaded;
+	}
+
+	private static boolean loadLibraryFromJar( String libraryName, ClassLoader classLoader ) {
+		// add prefix and suffix to library name
+		libraryName = decorateLibraryName( libraryName );
+
+		// find library
+		URL libraryUrl = classLoader.getResource( libraryName );
+		if( libraryUrl == null ) {
+			log( "Library '" + libraryName + "' not found", null );
+			return false;
+		}
+
+		File tempFile = null;
+		try {
+			// for development environment
+			if( "file".equals( libraryUrl.getProtocol() ) ) {
+				File libraryFile = new File( libraryUrl.getPath() );
+				if( libraryFile.isFile() ) {
+					// load library without copying
+					System.load( libraryFile.getCanonicalPath() );
+					return true;
+				}
+			}
+
+			// create temporary file
+			Path tempPath = createTempFile( libraryName );
+			tempFile = tempPath.toFile();
+
+			// copy library to temporary file
+			try( InputStream in = libraryUrl.openStream() ) {
+				Files.copy( in, tempPath, StandardCopyOption.REPLACE_EXISTING );
+			}
+
+			// load library
+			System.load( tempFile.getCanonicalPath() );
+
+			// delete library
+			deleteOrMarkForDeletion( tempFile );
+
+			return true;
+		} catch( Throwable ex ) {
+			log( null, ex );
+
+			if( tempFile != null )
+				deleteOrMarkForDeletion( tempFile );
+			return false;
+		}
+	}
+
+	private static String decorateLibraryName( String libraryName ) {
+		if( SystemInfo.isWindows )
+			return libraryName.concat( ".dll" );
+
+		String suffix = SystemInfo.isMacOS ? ".dylib" : ".so";
+
+		int sep = libraryName.lastIndexOf( '/' );
+		return (sep >= 0)
+			? libraryName.substring( 0, sep + 1 ) + "lib" + libraryName.substring( sep + 1 ) + suffix
+			: "lib" + libraryName + suffix;
+	}
+
+	private static void log( String msg, Throwable thrown ) {
+		Logger.getLogger( FlatLaf.class.getName() ).log( Level.SEVERE, msg, thrown );
+	}
+
+	private static Path createTempFile( String libraryName ) throws IOException {
+		int sep = libraryName.lastIndexOf( '/' );
+		String name = (sep >= 0) ? libraryName.substring( sep + 1 ) : libraryName;
+
+		int dot = name.lastIndexOf( '.' );
+		String prefix = ((dot >= 0) ? name.substring( 0, dot ) : name) + '-';
+		String suffix = (dot >= 0) ? name.substring( dot ) : "";
+
+		Path tempDir = getTempDir();
+		if( tempDir != null ) {
+			deleteTemporaryFiles( tempDir );
+
+			return Files.createTempFile( tempDir, prefix, suffix );
+		} else
+			return Files.createTempFile( prefix, suffix );
+	}
+
+	private static Path getTempDir() throws IOException {
+		if( SystemInfo.isWindows ) {
+			// On Windows, where File.delete() and File.deleteOnExit() does not work
+			// for loaded native libraries, they will be deleted on next application startup.
+			// The default temporary directory may contain hundreds or thousands of files.
+			// To make searching for "marked for deletion" files as fast as possible,
+			// use a sub directory that contains only our temporary native libraries.
+			Path tempDir = Paths.get( System.getProperty( "java.io.tmpdir" ) + "/flatlaf.temp" );
+			Files.createDirectories( tempDir );
+			return tempDir;
+		} else
+			return null; // use standard temporary directory
+	}
+
+	private static void deleteTemporaryFiles( Path tempDir ) {
+		if( deletedTemporary )
+			return;
+		deletedTemporary = true;
+
+		File[] markerFiles = tempDir.toFile().listFiles( (dir, name) -> name.endsWith( DELETE_SUFFIX ) );
+		if( markerFiles == null )
+			return;
+
+		for( File markerFile : markerFiles ) {
+			File toDeleteFile = new File( markerFile.getParent(), StringUtils.removeTrailing( markerFile.getName(), DELETE_SUFFIX ) );
+			if( !toDeleteFile.exists() || toDeleteFile.delete() )
+				markerFile.delete();
+		}
+	}
+
+	private static void deleteOrMarkForDeletion( File file ) {
+		// try to delete the native library
+		if( file.delete() )
+			return;
+
+		// not possible to delete on Windows because native library file is locked
+		// --> create "to delete" marker file (used at next startup)
+		try {
+			File markFile = new File( file.getParent(), file.getName() + DELETE_SUFFIX );
+			markFile.createNewFile();
+		} catch( IOException ex2 ) {
+			// ignore
+		}
+	}
+}
--- a/flatlaf-core/src/main/resources/com/formdev/flatlaf/FlatLaf.properties
+++ b/flatlaf-core/src/main/resources/com/formdev/flatlaf/FlatLaf.properties
@@ -685,6 +685,7 @@ TitledBorder.border = 1,1,1,1,$Separator.foreground

 #---- TitlePane ----

+TitlePane.useWindowDecorations = true
 TitlePane.menuBarEmbedded = true
 TitlePane.iconSize = 16,16
 TitlePane.iconMargins = 3,8,3,0
--- a/flatlaf-core/src/main/resources/com/formdev/flatlaf/natives/flatlaf-windows-x86_64.dll
+++ b/flatlaf-core/src/main/resources/com/formdev/flatlaf/natives/flatlaf-windows-x86_64.dll
--- a/flatlaf-demo/build.gradle.kts
+++ b/flatlaf-demo/build.gradle.kts
@@ -27,19 +27,19 @@ repositories {

 dependencies {
 	implementation( project( ":flatlaf-core" ) )
-	implementation( project( ":flatlaf-natives-jna" ) )
 	implementation( project( ":flatlaf-extras" ) )
 	implementation( project( ":flatlaf-intellij-themes" ) )
 	implementation( "com.miglayout:miglayout-swing:5.3-SNAPSHOT" )
 	implementation( "com.jgoodies:jgoodies-forms:1.9.0" )
+//	implementation( project( ":flatlaf-natives-jna" ) )
 }

 tasks {
 	jar {
 		dependsOn( ":flatlaf-core:jar" )
-		dependsOn( ":flatlaf-natives-jna:jar" )
 		dependsOn( ":flatlaf-extras:jar" )
 		dependsOn( ":flatlaf-intellij-themes:jar" )
+//		dependsOn( ":flatlaf-natives-jna:jar" )

 		manifest {
 			attributes( "Main-Class" to "com.formdev.flatlaf.demo.FlatLafDemo" )
--- a/flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DemoFrame.java
+++ b/flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DemoFrame.java
@@ -155,8 +155,7 @@ class DemoFrame
 		menuBarEmbeddedCheckBoxMenuItem.setEnabled( windowDecorations );

 		// enable/disable window decoration for later created frames/dialogs
-		JFrame.setDefaultLookAndFeelDecorated( windowDecorations );
-		JDialog.setDefaultLookAndFeelDecorated( windowDecorations );
+		UIManager.put( "TitlePane.useWindowDecorations", windowDecorations );
 	}

 	private void menuBarEmbeddedChanged() {
--- a/flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/FlatLafDemo.java
+++ b/flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/FlatLafDemo.java
@@ -17,8 +17,6 @@
 package com.formdev.flatlaf.demo;

 import java.awt.Dimension;
-import javax.swing.JDialog;
-import javax.swing.JFrame;
 import javax.swing.SwingUtilities;
 import com.formdev.flatlaf.FlatLaf;
 import com.formdev.flatlaf.extras.FlatInspector;
@@ -46,10 +44,6 @@ public class FlatLafDemo
 		SwingUtilities.invokeLater( () -> {
 			DemoPrefs.init( PREFS_ROOT_PATH );

-			// enable window decorations
-			JFrame.setDefaultLookAndFeelDecorated( true );
-			JDialog.setDefaultLookAndFeelDecorated( true );
-
 			// application specific UI defaults
 			FlatLaf.registerCustomDefaultsSource( "com.formdev.flatlaf.demo" );

--- a/flatlaf-natives/README.md
+++ b/flatlaf-natives/README.md
@@ -0,0 +1,5 @@
+FlatLaf Native Libraries
+========================
+
+- [Windows 10 Native Library](flatlaf-natives-windows)
+- [Natives using JNA](flatlaf-natives-jna) (for development only)
--- a/flatlaf-natives/flatlaf-natives-jna/README.md
+++ b/flatlaf-natives/flatlaf-natives-jna/README.md
@@ -0,0 +1,10 @@
+FlatLaf Natives using JNA
+=========================
+
+This sub-project contains source code that uses
+[JNA](https://github.com/java-native-access/jna) to access native operating
+system API.
+
+**Note:** Code in this sub-project is **not used** in FlatLaf libraries. It was
+used to develop/test usage of some native operating system API in Java (with the
+help of JNA) and was then converted to C++.
--- a/flatlaf-natives/flatlaf-natives-jna/src/main/java/com/formdev/flatlaf/natives/jna/windows/FlatWindowsNativeWindowBorder.java
+++ b/flatlaf-natives/flatlaf-natives-jna/src/main/java/com/formdev/flatlaf/natives/jna/windows/FlatWindowsNativeWindowBorder.java
@@ -207,20 +207,20 @@ public class FlatWindowsNativeWindowBorder

 		String subKey = "SOFTWARE\\Microsoft\\Windows\\DWM";

-		int value = RegGetDword( HKEY_CURRENT_USER, subKey, "ColorPrevalence" );
+		int value = registryGetIntValue( subKey, "ColorPrevalence", -1 );
 		colorizationColorAffectsBorders = (value > 0);

-		value = RegGetDword( HKEY_CURRENT_USER, subKey, "ColorizationColor" );
+		value = registryGetIntValue( subKey, "ColorizationColor", -1 );
 		colorizationColor = (value != -1) ? new Color( value ) : null;

-		colorizationColorBalance = RegGetDword( HKEY_CURRENT_USER, subKey, "ColorizationColorBalance" );
+		colorizationColorBalance = registryGetIntValue( subKey, "ColorizationColorBalance", -1 );
 	}

-	private static int RegGetDword( HKEY hkey, String lpSubKey, String lpValue ) {
+	private static int registryGetIntValue( String key, String valueName, int defaultValue ) {
 		try {
-			return Advapi32Util.registryGetIntValue( hkey, lpSubKey, lpValue );
+			return Advapi32Util.registryGetIntValue( HKEY_CURRENT_USER, key, valueName );
 		} catch( RuntimeException ex ) {
-			return -1;
+			return defaultValue;
 		}
 	}

--- a/flatlaf-natives/flatlaf-natives-windows/README.md
+++ b/flatlaf-natives/flatlaf-natives-windows/README.md
@@ -0,0 +1,17 @@
+FlatLaf Windows 10 Native Library
+=================================
+
+This sub-project contains the source code for the FlatLaf Windows 10 native
+library (DLL).
+
+The native library can be built only on Windows and requires a C++ compiler.
+Tested only with Microsoft Visual C++ 2019 (comes with Visual Studio 2019).
+
+To be able to build FlatLaf on any platform, and without C++ compiler, the
+pre-built DLL is checked into Git at
+`flatlaf-core/src/main/resources/com/formdev/flatlaf/natives/flatlaf-windows-x86_64.dll`.
+
+This DLL was built on a GitHub server with the help of GitHub Actions. See:
+[Native Libraries](https://github.com/JFormDesigner/FlatLaf/actions/workflows/natives.yml)
+workflow. Then the produced Artifacts ZIP was downloaded and the DLL checked
+into Git.
--- a/flatlaf-natives/flatlaf-natives-windows/build.gradle.kts
+++ b/flatlaf-natives/flatlaf-natives-windows/build.gradle.kts
@@ -0,0 +1,98 @@
+/*
+ * Copyright 2021 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.
+ */
+
+plugins {
+	id( "dev.nokee.jni-library" ) version "0.4.0"
+	id( "dev.nokee.cpp-language" ) version "0.4.0"
+}
+
+library {
+	targetMachines.set( listOf( machines.windows.x86_64 ) )
+
+	variants.configureEach {
+		// depend on :flatlaf-core:compileJava because this task generates the JNI headers
+		tasks.named( "compileCpp" ) {
+			dependsOn( ":flatlaf-core:compileJava" )
+		}
+
+		sharedLibrary {
+			compileTasks.configureEach {
+				onlyIf { isBuildable }
+
+				doFirst {
+					println( "Used Tool Chain:" )
+					println( "  - ${toolChain.get()}" )
+					println( "Available Tool Chains:" )
+					toolChains.forEach {
+						println( "  - $it" )
+					}
+
+					// copy needed JNI headers
+					copy {
+						from( project( ":flatlaf-core" ).buildDir.resolve( "generated/jni-headers" ) )
+						into( "src/main/headers" )
+						include(
+							"com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder.h",
+							"com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc.h"
+						)
+						filter<org.apache.tools.ant.filters.FixCrLfFilter>(
+							"eol" to org.apache.tools.ant.filters.FixCrLfFilter.CrLf.newInstance( "lf" )
+						)
+					}
+				}
+
+				compilerArgs.addAll( toolChain.map {
+					when( it ) {
+						is Gcc, is Clang -> listOf( "-O2" )
+						is VisualCpp -> listOf( "/O2", "/Zl", "/GS-" )
+						else -> emptyList()
+					}
+				} )
+			}
+
+			linkTask.configure {
+				onlyIf { isBuildable }
+
+				val nativesDir = project( ":flatlaf-core" ).projectDir.resolve( "src/main/resources/com/formdev/flatlaf/natives" )
+				val libraryName = "flatlaf-windows-x86_64.dll"
+
+				outputs.file( "$nativesDir/$libraryName" )
+
+				val jawt = "${org.gradle.internal.jvm.Jvm.current().javaHome}/lib/jawt"
+				linkerArgs.addAll( toolChain.map {
+					when( it ) {
+						is Gcc, is Clang -> listOf( "-l${jawt}", "-lUser32", "-lshell32", "-lAdvAPI32", "-lKernel32" )
+						is VisualCpp -> listOf( "${jawt}.lib", "User32.lib", "shell32.lib", "AdvAPI32.lib", "Kernel32.lib", "/NODEFAULTLIB" )
+						else -> emptyList()
+					}
+				} )
+
+				doLast {
+					// copy shared library to flatlaf-core resources
+					copy {
+						from( linkedFile )
+						into( nativesDir )
+						rename( "flatlaf-natives-windows.dll", libraryName )
+					}
+				}
+			}
+
+			tasks.named( "jar" ) {
+				onlyIf { false }
+			}
+		}
+	}
+}
--- a/flatlaf-natives/flatlaf-natives-windows/src/main/cpp/FlatWndProc.cpp
+++ b/flatlaf-natives/flatlaf-natives-windows/src/main/cpp/FlatWndProc.cpp
@@ -0,0 +1,409 @@
+/*
+ * Copyright 2021 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.
+ */
+
+// avoid inlining of printf()
+#define _NO_CRT_STDIO_INLINE
+
+#include <windows.h>
+#include <windowsx.h>
+#include <shellapi.h>
+#include <jawt.h>
+#include <jawt_md.h>
+#include "FlatWndProc.h"
+#include "com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc.h"
+
+/**
+ * @author Karl Tauber
+ */
+
+//---- JNI methods ------------------------------------------------------------
+
+extern "C"
+JNIEXPORT jlong JNICALL Java_com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_00024WndProc_installImpl
+	( JNIEnv *env, jobject obj, jobject window )
+{
+	return reinterpret_cast<jlong>( FlatWndProc::install( env, obj, window ) );
+}
+
+extern "C"
+JNIEXPORT void JNICALL Java_com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_00024WndProc_uninstallImpl
+	( JNIEnv* env, jobject obj, jlong hwnd )
+{
+	FlatWndProc::uninstall( env, obj, reinterpret_cast<HWND>( hwnd ) );
+}
+
+//---- class FlatWndProc fields -----------------------------------------------
+
+int FlatWndProc::initialized = 0;
+jmethodID FlatWndProc::onNcHitTestMID;
+jmethodID FlatWndProc::isFullscreenMID;
+jmethodID FlatWndProc::fireStateChangedLaterOnceMID;
+
+HWNDMap* FlatWndProc::hwndMap;
+
+//---- class FlatWndProc methods ----------------------------------------------
+
+FlatWndProc::FlatWndProc() {
+	jvm = NULL;
+	env = NULL;
+	obj = NULL;
+	hwnd = NULL;
+	defaultWndProc = NULL;
+}
+
+HWND FlatWndProc::install( JNIEnv *env, jobject obj, jobject window ) {
+	initIDs( env, obj );
+
+	if( initialized < 0 )
+		return 0;
+
+	// create HWND map
+	if( hwndMap == NULL )
+		hwndMap = new HWNDMap();
+
+	// get window handle
+	HWND hwnd = getWindowHandle( env, window );
+	if( hwnd == NULL || hwndMap->get( hwnd ) != NULL )
+		return 0;
+
+	FlatWndProc* fwp = new FlatWndProc();
+	env->GetJavaVM( &fwp->jvm );
+	fwp->obj = env->NewGlobalRef( obj );
+	fwp->hwnd = hwnd;
+	hwndMap->put( hwnd, fwp );
+
+	// replace window procedure
+	fwp->defaultWndProc = reinterpret_cast<WNDPROC>(
+		::SetWindowLongPtr( hwnd, GWLP_WNDPROC, (LONG_PTR) FlatWndProc::StaticWindowProc ) );
+
+	// remove the OS window title bar
+	fwp->updateFrame();
+
+	return hwnd;
+}
+
+void FlatWndProc::uninstall( JNIEnv *env, jobject obj, HWND hwnd ) {
+	if( hwnd == NULL )
+		return;
+
+	FlatWndProc* fwp = (FlatWndProc*) hwndMap->get( hwnd );
+	if( fwp == NULL )
+		return;
+
+	hwndMap->remove( hwnd );
+
+	// restore original window procedure
+	::SetWindowLongPtr( hwnd, GWLP_WNDPROC, (LONG_PTR) fwp->defaultWndProc );
+
+	// show the OS window title bar
+	fwp->updateFrame();
+
+	// cleanup
+	env->DeleteGlobalRef( fwp->obj );
+	delete fwp;
+}
+
+void FlatWndProc::initIDs( JNIEnv *env, jobject obj ) {
+	if( initialized )
+		return;
+
+	initialized = -1;
+
+	jclass cls = env->GetObjectClass( obj );
+	onNcHitTestMID = env->GetMethodID( cls, "onNcHitTest", "(IIZ)I" );
+	isFullscreenMID = env->GetMethodID( cls, "isFullscreen", "()Z" );
+	fireStateChangedLaterOnceMID = env->GetMethodID( cls, "fireStateChangedLaterOnce", "()V" );
+
+	// check whether all IDs were found
+	if( onNcHitTestMID != NULL &&
+		isFullscreenMID != NULL &&
+		fireStateChangedLaterOnceMID != NULL )
+	  initialized = 1;
+}
+
+void FlatWndProc::updateFrame() {
+	// this sends WM_NCCALCSIZE and removes/shows the window title bar
+	::SetWindowPos( hwnd, hwnd, 0, 0, 0, 0,
+		SWP_FRAMECHANGED | SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER );
+}
+
+LRESULT CALLBACK FlatWndProc::StaticWindowProc( HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam ) {
+	FlatWndProc* fwp = (FlatWndProc*) hwndMap->get( hwnd );
+	return fwp->WindowProc( hwnd, uMsg, wParam, lParam );
+}
+
+/**
+ * NOTE: This method is invoked on the AWT-Windows thread (not the AWT-EventQueue thread).
+ */
+LRESULT CALLBACK FlatWndProc::WindowProc( HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam ) {
+	switch( uMsg ) {
+		case WM_NCCALCSIZE:
+			return WmNcCalcSize( hwnd, uMsg, wParam, lParam );
+
+		case WM_NCHITTEST:
+			return WmNcHitTest( hwnd, uMsg, wParam, lParam );
+
+		case WM_NCRBUTTONUP:
+			if( wParam == HTCAPTION || wParam == HTSYSMENU )
+				openSystemMenu( hwnd, GET_X_LPARAM( lParam ), GET_Y_LPARAM( lParam ) );
+			break;
+
+		case WM_DWMCOLORIZATIONCOLORCHANGED:
+			fireStateChangedLaterOnce();
+			break;
+
+		case WM_DESTROY:
+			return WmDestroy( hwnd, uMsg, wParam, lParam );
+	}
+
+	return ::CallWindowProc( defaultWndProc, hwnd, uMsg, wParam, lParam );
+}
+/**
+ * Handle WM_DESTROY
+ *
+ * https://docs.microsoft.com/en-us/windows/win32/winmsg/wm-destroy
+ */
+LRESULT FlatWndProc::WmDestroy( HWND hwnd, int uMsg, WPARAM wParam, LPARAM lParam ) {
+	// restore original window procedure
+	::SetWindowLongPtr( hwnd, GWLP_WNDPROC, (LONG_PTR) defaultWndProc );
+
+	WNDPROC defaultWndProc2 = defaultWndProc;
+
+	// cleanup
+	getEnv()->DeleteGlobalRef( obj );
+	hwndMap->remove( hwnd );
+	delete this;
+
+	// call original AWT window procedure because it may fire window closed event in AwtWindow::WmDestroy()
+	return ::CallWindowProc( defaultWndProc2, hwnd, uMsg, wParam, lParam );
+}
+
+/**
+ * Handle WM_NCCALCSIZE
+ *
+ * https://docs.microsoft.com/en-us/windows/win32/winmsg/wm-nccalcsize
+ *
+ * See also NonClientIslandWindow::_OnNcCalcSize() here:
+ * https://github.com/microsoft/terminal/blob/main/src/cascadia/WindowsTerminal/NonClientIslandWindow.cpp
+ */
+LRESULT FlatWndProc::WmNcCalcSize( HWND hwnd, int uMsg, WPARAM wParam, LPARAM lParam ) {
+	if( wParam != TRUE )
+		return ::CallWindowProc( defaultWndProc, hwnd, uMsg, wParam, lParam );
+
+	NCCALCSIZE_PARAMS* params = reinterpret_cast<NCCALCSIZE_PARAMS*>( lParam );
+
+	// store the original top before the default window proc applies the default frame
+	int originalTop = params->rgrc[0].top;
+
+	// apply the default frame
+	LRESULT lResult = ::CallWindowProc( defaultWndProc, hwnd, uMsg, wParam, lParam );
+	if( lResult != 0 )
+		return lResult;
+
+	// re-apply the original top from before the size of the default frame was applied
+	params->rgrc[0].top = originalTop;
+
+	bool isMaximized = ::IsZoomed( hwnd );
+	if( isMaximized && !isFullscreen() ) {
+		// When a window is maximized, its size is actually a little bit more
+		// than the monitor's work area. The window is positioned and sized in
+		// such a way that the resize handles are outside of the monitor and
+		// then the window is clipped to the monitor so that the resize handle
+		// do not appear because you don't need them (because you can't resize
+		// a window when it's maximized unless you restore it).
+		params->rgrc[0].top += getResizeHandleHeight();
+
+		// check whether taskbar is in the autohide state
+		APPBARDATA autohide{ 0 };
+		autohide.cbSize = sizeof( autohide );
+		UINT state = (UINT) ::SHAppBarMessage( ABM_GETSTATE, &autohide );
+		if( (state & ABS_AUTOHIDE) != 0 ) {
+			// get monitor info
+			// (using MONITOR_DEFAULTTONEAREST finds right monitor when restoring from minimized)
+			HMONITOR hMonitor = ::MonitorFromWindow( hwnd, MONITOR_DEFAULTTONEAREST );
+			MONITORINFO monitorInfo{ 0 };
+			::GetMonitorInfo( hMonitor, &monitorInfo );
+
+			// If there's a taskbar on any side of the monitor, reduce our size
+			// a little bit on that edge.
+			if( hasAutohideTaskbar( ABE_TOP, monitorInfo.rcMonitor ) )
+				params->rgrc[0].top++;
+			if( hasAutohideTaskbar( ABE_BOTTOM, monitorInfo.rcMonitor ) )
+				params->rgrc[0].bottom--;
+			if( hasAutohideTaskbar( ABE_LEFT, monitorInfo.rcMonitor ) )
+				params->rgrc[0].left++;
+			if( hasAutohideTaskbar( ABE_RIGHT, monitorInfo.rcMonitor ) )
+				params->rgrc[0].right--;
+		}
+	}
+
+	return lResult;
+}
+
+/**
+ * Handle WM_NCHITTEST
+ *
+ * https://docs.microsoft.com/en-us/windows/win32/inputdev/wm-nchittest
+ *
+ * See also NonClientIslandWindow::_OnNcHitTest() here:
+ * https://github.com/microsoft/terminal/blob/main/src/cascadia/WindowsTerminal/NonClientIslandWindow.cpp
+ */
+LRESULT FlatWndProc::WmNcHitTest( HWND hwnd, int uMsg, WPARAM wParam, LPARAM lParam ) {
+	// this will handle the left, right and bottom parts of the frame because we didn't change them
+	LRESULT lResult = ::CallWindowProc( defaultWndProc, hwnd, uMsg, wParam, lParam );
+	if( lResult != HTCLIENT )
+		return lResult;
+
+	// get window rectangle needed to convert mouse x/y from screen to window coordinates
+	RECT rcWindow;
+	::GetWindowRect( hwnd, &rcWindow );
+
+	// get mouse x/y in window coordinates
+	int x = GET_X_LPARAM( lParam ) - rcWindow.left;
+	int y = GET_Y_LPARAM( lParam ) - rcWindow.top;
+
+	int resizeBorderHeight = getResizeHandleHeight();
+	bool isOnResizeBorder = (y < resizeBorderHeight) &&
+		(::GetWindowLong( hwnd, GWL_STYLE ) & WS_THICKFRAME) != 0;
+
+	return onNcHitTest( x, y, isOnResizeBorder );
+}
+
+/**
+ * Returns the height of the little space at the top of the window used to
+ * resize the window.
+ *
+ * See also NonClientIslandWindow::_GetResizeHandleHeight() here:
+ * https://github.com/microsoft/terminal/blob/main/src/cascadia/WindowsTerminal/NonClientIslandWindow.cpp
+ */
+int FlatWndProc::getResizeHandleHeight() {
+	int dpi = ::GetDpiForWindow( hwnd );
+
+	// there isn't a SM_CYPADDEDBORDER for the Y axis
+	return ::GetSystemMetricsForDpi( SM_CXPADDEDBORDER, dpi )
+		 + ::GetSystemMetricsForDpi( SM_CYSIZEFRAME, dpi );
+}
+
+/**
+ * Returns whether there is an autohide taskbar on the given edge.
+ */
+bool FlatWndProc::hasAutohideTaskbar( UINT edge, RECT rcMonitor ) {
+	APPBARDATA data{ 0 };
+	data.cbSize = sizeof( data );
+	data.uEdge = edge;
+	data.rc = rcMonitor;
+	HWND hTaskbar = (HWND) ::SHAppBarMessage( ABM_GETAUTOHIDEBAREX, &data );
+	return hTaskbar != nullptr;
+}
+
+BOOL FlatWndProc::isFullscreen() {
+	JNIEnv* env = getEnv();
+	if( env == NULL )
+		return FALSE;
+
+	return env->CallBooleanMethod( obj, isFullscreenMID );
+}
+
+int FlatWndProc::onNcHitTest( int x, int y, boolean isOnResizeBorder ) {
+	JNIEnv* env = getEnv();
+	if( env == NULL )
+		return isOnResizeBorder ? HTTOP : HTCLIENT;
+
+	return env->CallIntMethod( obj, onNcHitTestMID, (jint) x, (jint) y, (jboolean) isOnResizeBorder );
+}
+
+void FlatWndProc::fireStateChangedLaterOnce() {
+	JNIEnv* env = getEnv();
+	if( env == NULL )
+		return;
+
+	env->CallVoidMethod( obj, fireStateChangedLaterOnceMID );
+}
+
+// similar to JNU_GetEnv() in jni_util.c
+JNIEnv* FlatWndProc::getEnv() {
+	if( env != NULL )
+		return env;
+
+	jvm->GetEnv( (void **) &env, JNI_VERSION_1_2 );
+	return env;
+}
+
+/**
+ * Opens the window's system menu.
+ * The system menu is the menu that opens when the user presses Alt+Space or
+ * right clicks on the title bar
+ */
+void FlatWndProc::openSystemMenu( HWND hwnd, int x, int y ) {
+	// get system menu
+	HMENU systemMenu = ::GetSystemMenu( hwnd, false );
+
+	// update system menu
+	LONG style = ::GetWindowLong( hwnd, GWL_STYLE );
+	bool isMaximized = ::IsZoomed( hwnd );
+	setMenuItemState( systemMenu, SC_RESTORE, isMaximized );
+	setMenuItemState( systemMenu, SC_MOVE, !isMaximized );
+	setMenuItemState( systemMenu, SC_SIZE, (style & WS_THICKFRAME) != 0 && !isMaximized );
+	setMenuItemState( systemMenu, SC_MINIMIZE, (style & WS_MINIMIZEBOX) != 0 );
+	setMenuItemState( systemMenu, SC_MAXIMIZE, (style & WS_MAXIMIZEBOX) != 0 && !isMaximized );
+	setMenuItemState( systemMenu, SC_CLOSE, true );
+
+	// make "Close" item the default to be consistent with the system menu shown
+	// when pressing Alt+Space
+	::SetMenuDefaultItem( systemMenu, SC_CLOSE, 0 );
+
+	// show system menu
+	int ret = ::TrackPopupMenu( systemMenu, TPM_RETURNCMD, x, y, 0, hwnd, nullptr );
+	if( ret != 0 )
+		::PostMessage( hwnd, WM_SYSCOMMAND, ret, 0 );
+}
+
+void FlatWndProc::setMenuItemState( HMENU systemMenu, int item, bool enabled ) {
+	MENUITEMINFO mii{ 0 };
+	mii.cbSize = sizeof( mii );
+	mii.fMask = MIIM_STATE;
+	mii.fType = MFT_STRING;
+	mii.fState = enabled ? MF_ENABLED : MF_DISABLED;
+	::SetMenuItemInfo( systemMenu, item, FALSE, &mii );
+}
+
+HWND FlatWndProc::getWindowHandle( JNIEnv* env, jobject window ) {
+	JAWT awt;
+	awt.version = JAWT_VERSION_1_4;
+	if( !JAWT_GetAWT( env, &awt ) )
+		return 0;
+
+	jawt_DrawingSurface* ds = awt.GetDrawingSurface( env, window );
+	if( ds == NULL )
+		return 0;
+
+	jint lock = ds->Lock( ds );
+	if( (lock & JAWT_LOCK_ERROR) != 0 ) {
+		awt.FreeDrawingSurface( ds );
+		return 0;
+	}
+
+	JAWT_DrawingSurfaceInfo* dsi = ds->GetDrawingSurfaceInfo( ds );
+	JAWT_Win32DrawingSurfaceInfo* wdsi = (JAWT_Win32DrawingSurfaceInfo*) dsi->platformInfo;
+
+	HWND hwnd = wdsi->hwnd;
+
+	ds->FreeDrawingSurfaceInfo( dsi );
+	ds->Unlock( ds );
+	awt.FreeDrawingSurface( ds );
+
+	return hwnd;
+}
--- a/flatlaf-natives/flatlaf-natives-windows/src/main/cpp/FlatWndProc.h
+++ b/flatlaf-natives/flatlaf-natives-windows/src/main/cpp/FlatWndProc.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2021 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.
+ */
+
+#include <windows.h>
+#include "HWNDMap.h"
+
+/**
+ * @author Karl Tauber
+ */
+class FlatWndProc
+{
+public:
+	static HWND install( JNIEnv *env, jobject obj, jobject window );
+	static void uninstall( JNIEnv *env, jobject obj, HWND hwnd );
+
+private:
+	static int initialized;
+	static jmethodID onNcHitTestMID;
+	static jmethodID isFullscreenMID;
+	static jmethodID fireStateChangedLaterOnceMID;
+
+	static HWNDMap* hwndMap;
+
+	JavaVM* jvm;
+	JNIEnv* env; // attached to AWT-Windows/Win32 thread
+	jobject obj;
+	HWND hwnd;
+	WNDPROC defaultWndProc;
+
+	FlatWndProc();
+	static void initIDs( JNIEnv *env, jobject obj );
+	void updateFrame();
+
+	static LRESULT CALLBACK StaticWindowProc( HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam );
+	LRESULT CALLBACK WindowProc( HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam );
+	LRESULT WmDestroy( HWND hwnd, int uMsg, WPARAM wParam, LPARAM lParam );
+	LRESULT WmNcCalcSize( HWND hwnd, int uMsg, WPARAM wParam, LPARAM lParam );
+	LRESULT WmNcHitTest( HWND hwnd, int uMsg, WPARAM wParam, LPARAM lParam );
+
+	int getResizeHandleHeight();
+	bool hasAutohideTaskbar( UINT edge, RECT rcMonitor );
+	BOOL isFullscreen();
+	int onNcHitTest( int x, int y, boolean isOnResizeBorder );
+	void fireStateChangedLaterOnce();
+	JNIEnv* getEnv();
+
+	void openSystemMenu( HWND hwnd, int x, int y );
+	void setMenuItemState( HMENU systemMenu, int item, bool enabled );
+
+	static HWND getWindowHandle( JNIEnv* env, jobject window );
+};
--- a/flatlaf-natives/flatlaf-natives-windows/src/main/cpp/HWNDMap.cpp
+++ b/flatlaf-natives/flatlaf-natives-windows/src/main/cpp/HWNDMap.cpp
@@ -0,0 +1,153 @@
+/*
+ * Copyright 2021 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.
+ */
+
+// avoid inlining of printf()
+#define _NO_CRT_STDIO_INLINE
+
+#include <stdio.h>
+#include "HWNDMap.h"
+
+#define DEFAULT_CAPACITY		20
+#define INCREASE_CAPACITY		10
+
+/**
+ * @author Karl Tauber
+ */
+
+class LOCK {
+	LPCRITICAL_SECTION lpCriticalSection;
+
+public:
+	LOCK( LPCRITICAL_SECTION lpCriticalSection ) {
+		this->lpCriticalSection = lpCriticalSection;
+		::EnterCriticalSection( lpCriticalSection );
+	}
+	~LOCK() {
+		::LeaveCriticalSection( lpCriticalSection );
+	}
+};
+
+
+HWNDMap::HWNDMap() {
+	size = 0;
+	capacity = DEFAULT_CAPACITY;
+	table = new Entry[capacity];
+
+	::InitializeCriticalSection( &criticalSection );
+
+//	dump( "<init>" );
+}
+
+LPVOID HWNDMap::get( HWND key ) {
+	LOCK lock( &criticalSection );
+
+	int index = binarySearch( key );
+	return (index >= 0) ? table[index].value : NULL;
+}
+
+void HWNDMap::put( HWND key, LPVOID value ) {
+	LOCK lock( &criticalSection );
+
+	int index = binarySearch( key );
+//	printf( "put %p %p = %d --\n", key, value, index );
+	if( index >= 0 ) {
+		// key already in map --> replace
+		table[index].value = value;
+	} else {
+		// insert new key
+		ensureCapacity( size + 1 );
+
+		// make roor for new entry
+		index = -(index + 1);
+		for( int i = size - 1; i >= index; i-- )
+			table[i + 1] = table[i];
+		size++;
+
+		// insert entry
+		table[index].key = key;
+		table[index].value = value;
+	}
+
+//	dump( "put" );
+}
+
+void HWNDMap::remove( HWND key ) {
+	LOCK lock( &criticalSection );
+
+	// search for key
+	int index = binarySearch( key );
+//	printf( "remove %p = %d --\n", key, index );
+	if( index < 0 )
+		return;
+
+	// remove entry
+	for( int i = index + 1; i < size; i++ )
+		table[i - 1] = table[i];
+	size--;
+
+//	dump( "remove" );
+}
+
+int HWNDMap::binarySearch( HWND key ) {
+	int low = 0;
+	int high = size - 1;
+
+	while( low <= high ) {
+		int mid = (low + high) >> 1;
+
+		HWND midKey = table[mid].key;
+		int cmp = midKey - key;
+		if( cmp < 0 )
+			low = mid + 1;
+		else if( cmp > 0 )
+			high = mid - 1;
+		else
+			return mid;
+	}
+
+	return -(low + 1);
+}
+
+void HWNDMap::ensureCapacity( int minCapacity ) {
+	if( minCapacity <= capacity )
+		return;
+
+	// allocate new table
+	int newCapacity = minCapacity + INCREASE_CAPACITY;
+	Entry* newTable = new Entry[newCapacity];
+
+	// copy old table to new table
+	for( int i = 0; i < capacity; i++ )
+		newTable[i] = table[i];
+
+	// delete old table
+	delete table;
+
+	table = newTable;
+	capacity = newCapacity;
+}
+
+/*
+void HWNDMap::dump( char* msg ) {
+	printf( "---- %s -----------------------\n", msg );
+	printf( "size     %d\n", size );
+	printf( "capacity %d\n", capacity );
+	printf( "table    %p\n", table );
+
+	for( int i = 0; i < capacity; i++ )
+		printf( "  %d: %p - %p  %s\n", i, table[i].key, table[i].value, i >= size ? "UNUSED" : "" );
+}
+*/
--- a/flatlaf-natives/flatlaf-natives-windows/src/main/cpp/HWNDMap.h
+++ b/flatlaf-natives/flatlaf-natives-windows/src/main/cpp/HWNDMap.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2021 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.
+ */
+
+#include <windows.h>
+
+/**
+ * A simple map that uses a sorted array to store key/value pairs.
+ * 
+ * @author Karl Tauber
+ */
+
+struct Entry
+{
+	HWND key;
+	LPVOID value;
+};
+
+class HWNDMap
+{
+private:
+	int size; // used entries in table
+	int capacity; // total size of table
+	Entry* table;
+
+	// used to synchronize to make it thread safe
+	CRITICAL_SECTION criticalSection;
+
+public:
+	HWNDMap();
+
+	LPVOID get( HWND key );
+	void put( HWND key, LPVOID value );
+	void remove( HWND key );
+
+private:
+	int binarySearch( HWND key );
+	void ensureCapacity( int newCapacity );
+
+//	void dump( char* msg );
+};
--- a/flatlaf-natives/flatlaf-natives-windows/src/main/cpp/Registry.cpp
+++ b/flatlaf-natives/flatlaf-natives-windows/src/main/cpp/Registry.cpp
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2021 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.
+ */
+
+#include <windows.h>
+#include <winreg.h>
+#include <winerror.h>
+#include <jni.h>
+#include "com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder.h"
+
+/**
+ * @author Karl Tauber
+ */
+
+//---- JNI methods ------------------------------------------------------------
+
+extern "C"
+JNIEXPORT jint JNICALL Java_com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_registryGetIntValue
+	( JNIEnv* env, jclass cls, jstring key, jstring valueName, jint defaultValue )
+{
+	const char* skey = env->GetStringUTFChars( key, NULL );
+	const char* svalueName = env->GetStringUTFChars( valueName, NULL );
+
+	DWORD data = 0;
+	DWORD cbData = sizeof( data );
+	int rc = ::RegGetValueA( HKEY_CURRENT_USER, skey, svalueName, RRF_RT_DWORD, NULL, &data, &cbData );
+
+	env->ReleaseStringUTFChars( key, skey );
+	env->ReleaseStringUTFChars( valueName, svalueName );
+
+	return (rc == ERROR_SUCCESS) ? data : defaultValue;
+}
--- a/flatlaf-natives/flatlaf-natives-windows/src/main/cpp/Runtime.cpp
+++ b/flatlaf-natives/flatlaf-natives-windows/src/main/cpp/Runtime.cpp
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2021 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.
+ */
+
+// avoid inlining of printf()
+#define _NO_CRT_STDIO_INLINE
+
+#include <windows.h>
+#include <stdio.h>
+#include <stdarg.h>
+
+/**
+ * Methods that replace C-runtime methods and allow linking/running without C-runtime.
+ * 
+ * WARNING: Constructors/destructors of static objects are not invoked!
+ *
+ * https://documentation.help/Far-Manager/msdnmag-issues-01-01-hood-default.aspx.html
+ * www.catch22.net/tuts/win32/reducing-executable-size#the-c-runtime-and-default-libraries
+ * https://www.mvps.org/user32/nocrt.html
+ * 
+ * see also LIBCTINY on "Downloads" page here: http://www.wheaty.net/
+ * or https://github.com/leepa/libctiny
+ * 
+ * @author Karl Tauber
+ */
+
+extern "C"
+BOOL WINAPI _DllMainCRTStartup( HINSTANCE instance, DWORD reason, LPVOID reserved ) {
+	return TRUE;
+}
+
+void* __cdecl operator new( size_t cb ) {
+	return ::HeapAlloc( ::GetProcessHeap(), HEAP_ZERO_MEMORY, cb );
+}
+
+void* __cdecl operator new[]( size_t cb ) {
+	return ::HeapAlloc( ::GetProcessHeap(), HEAP_ZERO_MEMORY, cb );
+}
+
+void __cdecl operator delete( void* pv, size_t cb ) {
+	if( pv != NULL )
+		::HeapFree( ::GetProcessHeap(), 0, pv );
+}
+
+/*
+extern "C"
+int __cdecl printf( const char* format, ... ) {
+	char szBuff[1024];
+	int retValue;
+	DWORD cbWritten;
+	va_list argptr;
+
+	va_start( argptr, format );
+	retValue = wvsprintfA( szBuff, format, argptr );
+	va_end( argptr );
+
+	WriteFile( GetStdHandle( STD_OUTPUT_HANDLE ), szBuff, retValue, &cbWritten, NULL );
+
+	return retValue;
+}
+*/
--- a/flatlaf-natives/flatlaf-natives-windows/src/main/headers/com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder.h
+++ b/flatlaf-natives/flatlaf-natives-windows/src/main/headers/com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder.h
@@ -0,0 +1,21 @@
+/* DO NOT EDIT THIS FILE - it is machine generated */
+#include <jni.h>
+/* Header for class com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder */
+
+#ifndef _Included_com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder
+#define _Included_com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder
+#ifdef __cplusplus
+extern "C" {
+#endif
+/*
+ * Class:     com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder
+ * Method:    registryGetIntValue
+ * Signature: (Ljava/lang/String;Ljava/lang/String;I)I
+ */
+JNIEXPORT jint JNICALL Java_com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_registryGetIntValue
+  (JNIEnv *, jclass, jstring, jstring, jint);
+
+#ifdef __cplusplus
+}
+#endif
+#endif
--- a/flatlaf-natives/flatlaf-natives-windows/src/main/headers/com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc.h
+++ b/flatlaf-natives/flatlaf-natives-windows/src/main/headers/com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc.h
@@ -0,0 +1,37 @@
+/* DO NOT EDIT THIS FILE - it is machine generated */
+#include <jni.h>
+/* Header for class com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc */
+
+#ifndef _Included_com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc
+#define _Included_com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc
+#ifdef __cplusplus
+extern "C" {
+#endif
+#undef com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc_HTCLIENT
+#define com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc_HTCLIENT 1L
+#undef com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc_HTCAPTION
+#define com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc_HTCAPTION 2L
+#undef com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc_HTSYSMENU
+#define com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc_HTSYSMENU 3L
+#undef com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc_HTTOP
+#define com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc_HTTOP 12L
+/*
+ * Class:     com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc
+ * Method:    installImpl
+ * Signature: (Ljava/awt/Window;)J
+ */
+JNIEXPORT jlong JNICALL Java_com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_00024WndProc_installImpl
+  (JNIEnv *, jobject, jobject);
+
+/*
+ * Class:     com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_WndProc
+ * Method:    uninstallImpl
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL Java_com_formdev_flatlaf_ui_FlatWindowsNativeWindowBorder_00024WndProc_uninstallImpl
+  (JNIEnv *, jobject, jlong);
+
+#ifdef __cplusplus
+}
+#endif
+#endif
--- a/flatlaf-testing/build.gradle.kts
+++ b/flatlaf-testing/build.gradle.kts
@@ -27,12 +27,12 @@ repositories {

 dependencies {
 	implementation( project( ":flatlaf-core" ) )
-	implementation( project( ":flatlaf-natives-jna" ) )
 	implementation( project( ":flatlaf-extras" ) )
 	implementation( project( ":flatlaf-swingx" ) )
 	implementation( project( ":flatlaf-jide-oss" ) )
 	implementation( project( ":flatlaf-intellij-themes" ) )
 	implementation( project( ":flatlaf-demo" ) )
+//	implementation( project( ":flatlaf-natives-jna" ) )

 	implementation( "com.miglayout:miglayout-swing:5.3-SNAPSHOT" )
 	implementation( "com.jgoodies:jgoodies-forms:1.9.0" )
--- a/flatlaf-testing/dumps/uidefaults/FlatDarkLaf_1.8.0_202.txt
+++ b/flatlaf-testing/dumps/uidefaults/FlatDarkLaf_1.8.0_202.txt
@@ -1143,6 +1143,7 @@ TitlePane.menuBarEmbedded      true
 TitlePane.menuBarMargins       0,8,0,22    javax.swing.plaf.InsetsUIResource [UI]
 TitlePane.restoreIcon          [lazy] 44,30    com.formdev.flatlaf.icons.FlatWindowRestoreIcon [UI]
 TitlePane.titleMargins         3,8,3,8    javax.swing.plaf.InsetsUIResource [UI]
+TitlePane.useWindowDecorations true


 #---- TitledBorder ----
--- a/flatlaf-testing/dumps/uidefaults/FlatLightLaf_1.8.0_202.txt
+++ b/flatlaf-testing/dumps/uidefaults/FlatLightLaf_1.8.0_202.txt
@@ -1148,6 +1148,7 @@ TitlePane.menuBarEmbedded      true
 TitlePane.menuBarMargins       0,8,0,22    javax.swing.plaf.InsetsUIResource [UI]
 TitlePane.restoreIcon          [lazy] 44,30    com.formdev.flatlaf.icons.FlatWindowRestoreIcon [UI]
 TitlePane.titleMargins         3,8,3,8    javax.swing.plaf.InsetsUIResource [UI]
+TitlePane.useWindowDecorations true


 #---- TitledBorder ----
--- a/flatlaf-testing/dumps/uidefaults/FlatTestLaf_1.8.0_202.txt
+++ b/flatlaf-testing/dumps/uidefaults/FlatTestLaf_1.8.0_202.txt
@@ -1140,6 +1140,7 @@ TitlePane.menuBarEmbedded      true
 TitlePane.menuBarMargins       0,8,0,22    javax.swing.plaf.InsetsUIResource [UI]
 TitlePane.restoreIcon          [lazy] 44,30    com.formdev.flatlaf.icons.FlatWindowRestoreIcon [UI]
 TitlePane.titleMargins         3,8,3,8    javax.swing.plaf.InsetsUIResource [UI]
+TitlePane.useWindowDecorations true


 #---- TitledBorder ----
--- a/flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatNativeWindowBorderTest.java
+++ b/flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatNativeWindowBorderTest.java
@@ -50,9 +50,6 @@ public class FlatNativeWindowBorderTest
 			FlatLightLaf.install();
 			FlatInspector.install( "ctrl shift alt X" );

-			JFrame.setDefaultLookAndFeelDecorated( true );
-			JDialog.setDefaultLookAndFeelDecorated( true );
-
 			mainFrame = showFrame();
 		} );
 	}
--- a/flatlaf-theme-editor/src/main/resources/com/formdev/flatlaf/themeeditor/FlatLafUIKeys.txt
+++ b/flatlaf-theme-editor/src/main/resources/com/formdev/flatlaf/themeeditor/FlatLafUIKeys.txt
@@ -853,6 +853,7 @@ TitlePane.menuBarEmbedded
 TitlePane.menuBarMargins
 TitlePane.restoreIcon
 TitlePane.titleMargins
+TitlePane.useWindowDecorations
 TitledBorder.border
 TitledBorder.font
 TitledBorder.titleColor
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -25,6 +25,7 @@ include( "flatlaf-demo" )
 include( "flatlaf-testing" )
 include( "flatlaf-theme-editor" )

+includeProject( "flatlaf-natives-windows", "flatlaf-natives/flatlaf-natives-windows" )
 includeProject( "flatlaf-natives-jna",     "flatlaf-natives/flatlaf-natives-jna" )

 fun includeProject( projectPath: String, projectDir: String ) {