Merge pull request #267 from native-window-decorations

Native window decorations for Windows 10 (using JNI)

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();
 	}
 

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

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 ) {

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();
+		}
+	}
+}

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;
 

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
+		}
+	}
+}

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