Merge PR #779: macOS: window title bar close/minimize/zoom buttons spacing

CHANGELOG.md

@@ -5,6 +5,9 @@ FlatLaf Change Log
 
 #### New features and improvements
 
+- macOS: Support larger window title bar close/minimize/zoom buttons spacing in
+  [full window content](https://www.formdev.com/flatlaf/macos/#full_window_content)
+  mode and introduced "buttons placeholder". (PR #779)
 - Native libraries: System property `flatlaf.nativeLibraryPath` now supports
   loading native libraries named the same as on Maven central. Improved log
   messages for loading fails.

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

@@ -270,6 +270,80 @@ public interface FlatClientProperties
 	String COMPONENT_TITLE_BAR_CAPTION = "JComponent.titleBarCaption";
 
 
+	//---- Panel --------------------------------------------------------------
+
+	/**
+	 * Marks the panel as placeholder for the iconfify/maximize/close buttons
+	 * in fullWindowContent mode.
+	 * <p>
+	 * If fullWindowContent mode is enabled, the preferred size of the panel is equal
+	 * to the size of the iconfify/maximize/close buttons. Otherwise is is {@code 0,0}.
+	 * <p>
+	 * You're responsible to layout that panel at the top-left or top-right corner,
+	 * depending on platform, where the iconfify/maximize/close buttons are located.
+	 * <p>
+	 * Syntax of the value string is: {@code "win|mac [horizontal|vertical] [zeroInFullScreen] [leftToRight|rightToLeft]"}.
+	 * <p>
+	 * The string must start with {@code "win"} (for Windows or Linux) or
+	 * with {@code "mac"} (for macOS) and specifies the platform where the placeholder
+	 * should be used. On macOS, you need the placeholder in the top-left corner,
+	 * but on Windows/Linux you need it in the top-right corner. So if your application supports
+	 * fullWindowContent mode on both platforms, you can add two placeholders to your layout
+	 * and FlatLaf automatically uses only one of them. The other gets size {@code 0,0}.
+	 * <p>
+	 * Optionally, you can append following options to the value string (separated by space characters):
+	 * <ul>
+	 *   <li>{@code "horizontal"} - preferred height is zero
+	 *   <li>{@code "vertical"} - preferred width is zero
+	 *   <li>{@code "zeroInFullScreen"} - in full-screen mode on macOS, preferred size is {@code 0,0}
+	 *   <li>{@code "leftToRight"} - in right-to-left component orientation, preferred size is {@code 0,0}
+	 *   <li>{@code "rightToLeft"} - in left-to-right component orientation, preferred size is {@code 0,0}
+	 * </ul>
+	 *
+	 * Example for adding placeholder to top-left corner on macOS:
+	 * <pre>{@code
+	 * JPanel placeholder = new JPanel();
+	 * placeholder.putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER, "mac" );
+     *
+     * JToolBar toolBar = new JToolBar();
+     * // add tool bar items
+     *
+	 * JPanel toolBarPanel = new JPanel( new BorderLayout() );
+	 * toolBarPanel.add( placeholder, BorderLayout.WEST );
+	 * toolBarPanel.add( toolBar, BorderLayout.CENTER );
+	 *
+	 * frame.getContentPane().add( toolBarPanel, BorderLayout.NORTH );
+	 * }</pre>
+	 *
+	 * Or add placeholder as first item to the tool bar:
+	 * <pre>{@code
+	 * JPanel placeholder = new JPanel();
+	 * placeholder.putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER, "mac" );
+	 *
+	 * JToolBar toolBar = new JToolBar();
+	 * toolBar.add( placeholder );
+	 * // add tool bar items
+	 *
+	 * frame.getContentPane().add( toolBar, BorderLayout.NORTH );
+	 * }</pre>
+	 *
+	 * If a tabbed pane is located at the top, you can add the placeholder
+	 * as leading component to that tabbed pane:
+	 * <pre>{@code
+	 * JPanel placeholder = new JPanel();
+	 * placeholder.putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER, "mac" );
+	 *
+	 * tabbedPane.putClientProperty( FlatClientProperties.TABBED_PANE_LEADING_COMPONENT, placeholder );
+	 * }</pre>
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JPanel}<br>
+	 * <strong>Value type</strong> {@link java.lang.String}
+	 *
+	 * @since 3.4
+	 */
+	String FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER = "FlatLaf.fullWindowContent.buttonsPlaceholder";
+
+
 	//---- Popup --------------------------------------------------------------
 
 	/**
@@ -388,6 +462,20 @@ public interface FlatClientProperties
 	 */
 	String MENU_BAR_EMBEDDED = "JRootPane.menuBarEmbedded";
 
+	/**
+	 * Contains the current bounds of the iconfify/maximize/close buttons
+	 * (in root pane coordinates) if fullWindowContent mode is enabled.
+	 * Otherwise its value is {@code null}.
+	 * <p>
+	 * <b>Note</b>: Do not set this client property. It is set by FlatLaf.
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
+	 * <strong>Value type</strong> {@link java.awt.Rectangle}
+	 *
+	 * @since 3.4
+	 */
+	String FULL_WINDOW_CONTENT_BUTTONS_BOUNDS = "FlatLaf.fullWindowContent.buttonsBounds";
+
 	/**
 	 * Specifies whether the window icon should be shown in the window title bar
 	 * (requires enabled window decorations). Default is UI property {@code TitlePane.showIcon}.
@@ -1263,6 +1351,44 @@ public interface FlatClientProperties
 	String TREE_PAINT_SELECTION = "JTree.paintSelection";
 
 
+	//---- macOS --------------------------------------------------------------
+
+	/**
+	 * Specifies the spacing around the macOS window close/minimize/zoom buttons.
+	 * Useful if <a href="https://www.formdev.com/flatlaf/macos/#full_window_content">full window content</a>
+	 * is enabled.
+	 * <p>
+	 * (requires macOS 10.14+ for "medium" spacing and macOS 11+ for "large" spacing, requires Java 17+)
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
+	 * <strong>Value type</strong> {@link java.lang.String}<br>
+	 * <strong>Allowed Values</strong>
+	 *     {@link #MACOS_WINDOW_BUTTONS_SPACING_MEDIUM} or
+	 *     {@link #MACOS_WINDOW_BUTTONS_SPACING_LARGE} (requires macOS 11+)
+	 *
+	 * @since 3.4
+	 */
+	String MACOS_WINDOW_BUTTONS_SPACING = "FlatLaf.macOS.windowButtonsSpacing";
+
+	/**
+	 * Add medium spacing around the macOS window close/minimize/zoom buttons.
+	 *
+	 * @see #MACOS_WINDOW_BUTTONS_SPACING
+	 * @since 3.4
+	 */
+	String MACOS_WINDOW_BUTTONS_SPACING_MEDIUM = "medium";
+
+	/**
+	 * Add large spacing around the macOS window close/minimize/zoom buttons.
+	 * <p>
+	 * (requires macOS 11+; "medium" is used on older systems)
+	 *
+	 * @see #MACOS_WINDOW_BUTTONS_SPACING
+	 * @since 3.4
+	 */
+	String MACOS_WINDOW_BUTTONS_SPACING_LARGE = "large";
+
+
 	//---- helper methods -----------------------------------------------------
 
 	/**

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

@@ -16,7 +16,9 @@
 
 package com.formdev.flatlaf.ui;
 
+import java.awt.Rectangle;
 import java.awt.Window;
+import com.formdev.flatlaf.util.SystemInfo;
 
 /**
  * Native methods for macOS.
@@ -49,8 +51,19 @@ public class FlatNativeMacLibrary
 	 *              method of this class. Otherwise, the native library may not be loaded.
 	 */
 	public static boolean isLoaded() {
-		return FlatNativeLibrary.isLoaded();
+		return SystemInfo.isMacOS && FlatNativeLibrary.isLoaded();
 	}
 
 	public native static boolean setWindowRoundedBorder( Window window, float radius, float borderWidth, int borderColor );
+
+	/** @since 3.4 */
+	public static final int
+		BUTTONS_SPACING_DEFAULT = 0,
+		BUTTONS_SPACING_MEDIUM = 1,
+		BUTTONS_SPACING_LARGE = 2;
+
+	/** @since 3.4 */ public native static boolean setWindowButtonsSpacing( Window window, int buttonsSpacing );
+	/** @since 3.4 */ public native static Rectangle getWindowButtonsBounds( Window window );
+	/** @since 3.4 */ public native static boolean isWindowFullScreen( Window window );
+	/** @since 3.4 */ public native static boolean toggleWindowFullScreen( Window window );
 }

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

@@ -16,6 +16,7 @@
 
 package com.formdev.flatlaf.ui;
 
+import java.awt.Dimension;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.beans.PropertyChangeEvent;
@@ -23,6 +24,7 @@ import java.beans.PropertyChangeListener;
 import java.util.Map;
 import javax.swing.JComponent;
 import javax.swing.JPanel;
+import javax.swing.LookAndFeel;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.basic.BasicPanelUI;
 import com.formdev.flatlaf.FlatClientProperties;
@@ -69,6 +71,8 @@ public class FlatPanelUI
 		super.installUI( c );
 
 		c.addPropertyChangeListener( this );
+		if( c.getClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER ) != null )
+			FullWindowContentSupport.registerPlaceholder( c );
 
 		installStyle( (JPanel) c );
 	}
@@ -78,10 +82,20 @@ public class FlatPanelUI
 		super.uninstallUI( c );
 
 		c.removePropertyChangeListener( this );
+		if( c.getClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER ) != null )
+			FullWindowContentSupport.unregisterPlaceholder( c );
 
 		oldStyleValues = null;
 	}
 
+	@Override
+	protected void installDefaults( JPanel p ) {
+		super.installDefaults( p );
+
+		if( p.getClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER ) != null )
+			LookAndFeel.installProperty( p, "opaque", false );
+	}
+
 	/** @since 2.0.1 */
 	@Override
 	public void propertyChange( PropertyChangeEvent e ) {
@@ -98,6 +112,17 @@ public class FlatPanelUI
 				c.revalidate();
 				c.repaint();
 				break;
+
+			case FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER:
+				JPanel p = (JPanel) e.getSource();
+				if( e.getOldValue() != null )
+					FullWindowContentSupport.unregisterPlaceholder( p );
+				if( e.getNewValue() != null )
+					FullWindowContentSupport.registerPlaceholder( p );
+
+				// make panel non-opaque for placeholders
+				LookAndFeel.installProperty( p, "opaque", e.getNewValue() == null );
+				break;
 		}
 	}
 
@@ -162,4 +187,19 @@ public class FlatPanelUI
 
 		paint( g, c );
 	}
+
+	@Override
+	public Dimension getPreferredSize( JComponent c ) {
+		Object value = c.getClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER );
+		if( value != null )
+			return FullWindowContentSupport.getPlaceholderPreferredSize( c, (String) value );
+
+		return super.getPreferredSize( c );
+	}
+
+	@Override
+	public void paint( Graphics g, JComponent c ) {
+		if( c.getClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER ) != null )
+			FullWindowContentSupport.debugPaint( g, c );
+	}
 }

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

@@ -89,6 +89,7 @@ public class FlatRootPaneUI
 	private LayoutManager oldLayout;
 	private PropertyChangeListener ancestorListener;
 	private ComponentListener componentListener;
+	private ComponentListener macFullWindowContentListener;
 
 	public static ComponentUI createUI( JComponent c ) {
 		return new FlatRootPaneUI();
@@ -207,6 +208,9 @@ public class FlatRootPaneUI
 			};
 			root.addPropertyChangeListener( "ancestor", ancestorListener );
 		}
+
+		if( SystemInfo.isMacFullWindowContentSupported )
+			macFullWindowContentListener = FullWindowContentSupport.macInstallListeners( root );
 	}
 
 	@Override
@@ -223,6 +227,11 @@ public class FlatRootPaneUI
 			root.removePropertyChangeListener( "ancestor", ancestorListener );
 			ancestorListener = null;
 		}
+
+		if( SystemInfo.isMacFullWindowContentSupported ) {
+			FullWindowContentSupport.macUninstallListeners( root, macFullWindowContentListener );
+			macFullWindowContentListener = null;
+		}
 	}
 
 	/** @since 1.1.2 */
@@ -359,6 +368,10 @@ public class FlatRootPaneUI
 					titlePane.titleBarColorsChanged();
 				break;
 
+			case FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_BOUNDS:
+				FullWindowContentSupport.revalidatePlaceholders( rootPane );
+				break;
+
 			case FlatClientProperties.GLASS_PANE_FULL_HEIGHT:
 				rootPane.revalidate();
 				break;
@@ -367,6 +380,50 @@ public class FlatRootPaneUI
 				if( rootPane.isDisplayable() )
 					throw new IllegalComponentStateException( "The client property 'Window.style' must be set before the window becomes displayable." );
 				break;
+
+			case "ancestor":
+				// FlatNativeMacLibrary.setWindowButtonsSpacing() and
+				// FullWindowContentSupport.macUpdateFullWindowContentButtonsBoundsProperty()
+				// require a native window, but setting the client properties
+				// "apple.awt.fullWindowContent" or FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING
+				// is usually done before the native window is created
+				// --> try again when native window is created
+				if( !SystemInfo.isMacOS || e.getNewValue() == null )
+					break;
+
+				// fall through
+
+			case FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING:
+				if( SystemInfo.isMacOS ) {
+					// set window buttons spacing
+					if( SystemInfo.isJava_17_orLater && rootPane.isDisplayable() && FlatNativeMacLibrary.isLoaded() ) {
+						int buttonsSpacing = FlatNativeMacLibrary.BUTTONS_SPACING_DEFAULT;
+						String value = (String) rootPane.getClientProperty( FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING );
+						if( value != null ) {
+							switch( value ) {
+								case FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING_MEDIUM:
+									buttonsSpacing = FlatNativeMacLibrary.BUTTONS_SPACING_MEDIUM;
+									break;
+
+								case FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING_LARGE:
+									buttonsSpacing = FlatNativeMacLibrary.BUTTONS_SPACING_LARGE;
+									break;
+							}
+						}
+
+						Window window = SwingUtilities.windowForComponent( rootPane );
+						FlatNativeMacLibrary.setWindowButtonsSpacing( window, buttonsSpacing );
+					}
+
+					// update buttons bounds client property
+					FullWindowContentSupport.macUpdateFullWindowContentButtonsBoundsProperty( rootPane );
+				}
+				break;
+
+			case "apple.awt.fullWindowContent":
+				if( SystemInfo.isMacOS )
+					FullWindowContentSupport.macUpdateFullWindowContentButtonsBoundsProperty( rootPane );
+				break;
 		}
 	}
 

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

@@ -0,0 +1,210 @@
+/*
+ * Copyright 2024 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.ui;
+
+import java.awt.Color;
+import java.awt.Component;
+import java.awt.Dimension;
+import java.awt.Graphics;
+import java.awt.Rectangle;
+import java.awt.Window;
+import java.awt.event.ComponentAdapter;
+import java.awt.event.ComponentEvent;
+import java.awt.event.ComponentListener;
+import java.lang.ref.WeakReference;
+import java.util.ArrayList;
+import java.util.Iterator;
+import javax.swing.JComponent;
+import javax.swing.JRootPane;
+import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
+import com.formdev.flatlaf.FlatClientProperties;
+import com.formdev.flatlaf.util.SystemInfo;
+
+/**
+ * @author Karl Tauber
+ */
+class FullWindowContentSupport
+{
+	private static final String KEY_DEBUG_SHOW_PLACEHOLDERS = "FlatLaf.debug.panel.showPlaceholders";
+
+	private static ArrayList<WeakReference<JComponent>> placeholders = new ArrayList<>();
+
+	static Dimension getPlaceholderPreferredSize( JComponent c, String options ) {
+		JRootPane rootPane;
+		Rectangle bounds;
+
+		if( !options.startsWith( SystemInfo.isMacOS ? "mac" : "win" ) ||
+			!c.isDisplayable() ||
+			(rootPane = SwingUtilities.getRootPane( c )) == null ||
+			(bounds = (Rectangle) rootPane.getClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_BOUNDS )) == null )
+		  return new Dimension( 0, 0 );
+
+		if( options.length() > 3 ) {
+			if( (options.contains( "leftToRight" ) && !c.getComponentOrientation().isLeftToRight()) ||
+				(options.contains( "rightToLeft" ) && c.getComponentOrientation().isLeftToRight()) )
+			  return new Dimension( 0, 0 );
+		}
+
+		// On macOS, the client property is updated very late when toggling full screen,
+		// which results in "jumping" layout after full screen toggle finished.
+		// To avoid that, get up-to-date buttons bounds from macOS.
+		if( SystemInfo.isMacFullWindowContentSupported && FlatNativeMacLibrary.isLoaded() ) {
+			Rectangle r = FlatNativeMacLibrary.getWindowButtonsBounds( SwingUtilities.windowForComponent( c ) );
+			if( r != null )
+				bounds = r;
+		}
+
+		int width = bounds.width;
+		int height = bounds.height;
+
+		if( options.length() > 3 ) {
+			if( width == 0 && options.contains( "zeroInFullScreen" ) )
+				height = 0;
+
+			if( options.contains( "horizontal" ) )
+				height = 0;
+			if( options.contains( "vertical" ) )
+				width = 0;
+		}
+
+		return new Dimension( width, height );
+	}
+
+	static void registerPlaceholder( JComponent c ) {
+		synchronized( placeholders ) {
+			if( indexOfPlaceholder( c ) < 0 )
+				placeholders.add( new WeakReference<>( c ) );
+		}
+	}
+
+	static void unregisterPlaceholder( JComponent c ) {
+		synchronized( placeholders ) {
+			int index = indexOfPlaceholder( c );
+			if( index >= 0 )
+				placeholders.remove( index );
+		}
+	}
+
+	private static int indexOfPlaceholder( JComponent c ) {
+		int size = placeholders.size();
+		for( int i = 0; i < size; i++ ) {
+			if( placeholders.get( i ).get() == c )
+				return i;
+		}
+		return -1;
+	}
+
+	static void revalidatePlaceholders( Component container ) {
+		synchronized( placeholders ) {
+			if( placeholders.isEmpty() )
+				return;
+
+			for( Iterator<WeakReference<JComponent>> it = placeholders.iterator(); it.hasNext(); ) {
+				WeakReference<JComponent> ref = it.next();
+				JComponent c = ref.get();
+
+				// remove already released placeholder
+				if( c == null ) {
+					it.remove();
+					continue;
+				}
+
+				// revalidate placeholder if is in given container
+				if( SwingUtilities.isDescendingFrom( c, container ) )
+					c.revalidate();
+			}
+		}
+	}
+
+	static ComponentListener macInstallListeners( JRootPane rootPane ) {
+		ComponentListener l = new ComponentAdapter() {
+			boolean lastFullScreen;
+
+			@Override
+			public void componentResized( ComponentEvent e ) {
+				Window window = SwingUtilities.windowForComponent( rootPane );
+				if( window == null )
+					return;
+
+				boolean fullScreen = FlatNativeMacLibrary.isLoaded() && FlatNativeMacLibrary.isWindowFullScreen( window );
+				if( fullScreen == lastFullScreen )
+					return;
+
+				lastFullScreen = fullScreen;
+				macUpdateFullWindowContentButtonsBoundsProperty( rootPane );
+			}
+		};
+
+		rootPane.addComponentListener( l );
+		return l;
+	}
+
+	static void macUninstallListeners( JRootPane rootPane, ComponentListener l ) {
+		if( l != null )
+			rootPane.removeComponentListener( l );
+	}
+
+	static void macUpdateFullWindowContentButtonsBoundsProperty( JRootPane rootPane ) {
+		if( !SystemInfo.isMacFullWindowContentSupported || !rootPane.isDisplayable() )
+			return;
+
+		Rectangle bounds = null;
+		if( FlatClientProperties.clientPropertyBoolean( rootPane, "apple.awt.fullWindowContent", false ) ) {
+			bounds = FlatNativeMacLibrary.isLoaded()
+				? FlatNativeMacLibrary.getWindowButtonsBounds( SwingUtilities.windowForComponent( rootPane ) )
+				: new Rectangle( 68, 28 ); // default size
+		}
+		rootPane.putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_BOUNDS, bounds );
+	}
+
+	static void debugPaint( Graphics g, JComponent c ) {
+		if( !UIManager.getBoolean( KEY_DEBUG_SHOW_PLACEHOLDERS ) )
+			return;
+
+		int width = c.getWidth();
+		int height = c.getHeight();
+		if( width <= 0 || height <= 0 )
+			return;
+
+		// draw red figure
+		g.setColor( Color.red );
+		debugPaintRect( g, new Rectangle( width, height ) );
+
+		// draw magenta figure if buttons bounds are not equal to placeholder bounds
+		JRootPane rootPane;
+		Rectangle bounds;
+		if( (rootPane = SwingUtilities.getRootPane( c )) != null &&
+			(bounds = (Rectangle) rootPane.getClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_BOUNDS )) != null &&
+			(bounds.width != width || bounds.height != height) )
+		{
+			g.setColor( Color.magenta );
+			debugPaintRect( g, SwingUtilities.convertRectangle( rootPane, bounds, c ) );
+		}
+	}
+
+	private static void debugPaintRect( Graphics g, Rectangle r ) {
+		// draw rectangle
+		g.drawRect( r.x, r.y, r.width - 1, r.height - 1 );
+
+		// draw diagonal cross
+		Object[] oldRenderingHints = FlatUIUtils.setRenderingHints( g );
+		g.drawLine( r.x, r.y, r.width - 1, r.height - 1 );
+		g.drawLine( r.x, r.height - 1, r.width - 1, r.y );
+		FlatUIUtils.resetRenderingHints( g, oldRenderingHints );
+	}
+}

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

@@ -46,6 +46,7 @@ import com.formdev.flatlaf.icons.FlatAbstractIcon;
 import com.formdev.flatlaf.themes.FlatMacDarkLaf;
 import com.formdev.flatlaf.themes.FlatMacLightLaf;
 import com.formdev.flatlaf.extras.FlatSVGUtils;
+import com.formdev.flatlaf.ui.FlatNativeMacLibrary;
 import com.formdev.flatlaf.util.ColorFunctions;
 import com.formdev.flatlaf.util.FontUtils;
 import com.formdev.flatlaf.util.LoggingFacade;
@@ -89,24 +90,26 @@ class DemoFrame
 			// do not use HTML text in menu items because this is not supported in macOS screen menu
 			htmlMenuItem.setText( "some text" );
 
+			JRootPane rootPane = getRootPane();
 			if( SystemInfo.isMacFullWindowContentSupported ) {
 				// expand window content into window title bar and make title bar transparent
-				getRootPane().putClientProperty( "apple.awt.fullWindowContent", true );
+				rootPane.putClientProperty( "apple.awt.fullWindowContent", true );
-				getRootPane().putClientProperty( "apple.awt.transparentTitleBar", true );
+				rootPane.putClientProperty( "apple.awt.transparentTitleBar", true );
+				rootPane.putClientProperty( FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING, FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING_LARGE );
 
 				// hide window title
 				if( SystemInfo.isJava_17_orLater )
-					getRootPane().putClientProperty( "apple.awt.windowTitleVisible", false );
+					rootPane.putClientProperty( "apple.awt.windowTitleVisible", false );
 				else
 					setTitle( null );
 
-				// add gap to left side of toolbar
+				// uncomment this line to see title bar buttons placeholders in fullWindowContent mode
-				toolBar.add( Box.createHorizontalStrut( 70 ), 0 );
+//				UIManager.put( "FlatLaf.debug.panel.showPlaceholders", true );
 			}
 
 			// enable full screen mode for this window (for Java 8 - 10; not necessary for Java 11+)
 			if( !SystemInfo.isJava_11_orLater )
-				getRootPane().putClientProperty( "apple.awt.fullscreenable", true );
+				rootPane.putClientProperty( "apple.awt.fullscreenable", true );
 		}
 
 		// integrate into macOS screen menu
@@ -509,6 +512,8 @@ class DemoFrame
 		JMenuItem showUIDefaultsInspectorMenuItem = new JMenuItem();
 		JMenu helpMenu = new JMenu();
 		aboutMenuItem = new JMenuItem();
+		JPanel toolBarPanel = new JPanel();
+		JPanel macFullWindowContentButtonsPlaceholder = new JPanel();
 		toolBar = new JToolBar();
 		JButton backButton = new JButton();
 		JButton forwardButton = new JButton();
@@ -825,50 +830,62 @@ class DemoFrame
 		}
 		setJMenuBar(menuBar1);
 
-		//======== toolBar ========
+		//======== toolBarPanel ========
 		{
-			toolBar.setMargin(new Insets(3, 3, 3, 3));
+			toolBarPanel.setLayout(new BorderLayout());
 
-			//---- backButton ----
+			//======== macFullWindowContentButtonsPlaceholder ========
-			backButton.setToolTipText("Back");
+			{
-			backButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/back.svg"));
+				macFullWindowContentButtonsPlaceholder.setLayout(new FlowLayout());
-			toolBar.add(backButton);
+			}
+			toolBarPanel.add(macFullWindowContentButtonsPlaceholder, BorderLayout.WEST);
 
-			//---- forwardButton ----
+			//======== toolBar ========
-			forwardButton.setToolTipText("Forward");
+			{
-			forwardButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/forward.svg"));
+				toolBar.setMargin(new Insets(3, 3, 3, 3));
-			toolBar.add(forwardButton);
-			toolBar.addSeparator();
 
-			//---- cutButton ----
+				//---- backButton ----
-			cutButton.setToolTipText("Cut");
+				backButton.setToolTipText("Back");
-			cutButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/menu-cut.svg"));
+				backButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/back.svg"));
-			toolBar.add(cutButton);
+				toolBar.add(backButton);
 
-			//---- copyButton ----
+				//---- forwardButton ----
-			copyButton.setToolTipText("Copy");
+				forwardButton.setToolTipText("Forward");
-			copyButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/copy.svg"));
+				forwardButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/forward.svg"));
-			toolBar.add(copyButton);
+				toolBar.add(forwardButton);
+				toolBar.addSeparator();
 
-			//---- pasteButton ----
+				//---- cutButton ----
-			pasteButton.setToolTipText("Paste");
+				cutButton.setToolTipText("Cut");
-			pasteButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/menu-paste.svg"));
+				cutButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/menu-cut.svg"));
-			toolBar.add(pasteButton);
+				toolBar.add(cutButton);
-			toolBar.addSeparator();
 
-			//---- refreshButton ----
+				//---- copyButton ----
-			refreshButton.setToolTipText("Refresh");
+				copyButton.setToolTipText("Copy");
-			refreshButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/refresh.svg"));
+				copyButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/copy.svg"));
-			toolBar.add(refreshButton);
+				toolBar.add(copyButton);
-			toolBar.addSeparator();
 
-			//---- showToggleButton ----
+				//---- pasteButton ----
-			showToggleButton.setSelected(true);
+				pasteButton.setToolTipText("Paste");
-			showToggleButton.setToolTipText("Show Details");
+				pasteButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/menu-paste.svg"));
-			showToggleButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/show.svg"));
+				toolBar.add(pasteButton);
-			toolBar.add(showToggleButton);
+				toolBar.addSeparator();
+
+				//---- refreshButton ----
+				refreshButton.setToolTipText("Refresh");
+				refreshButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/refresh.svg"));
+				toolBar.add(refreshButton);
+				toolBar.addSeparator();
+
+				//---- showToggleButton ----
+				showToggleButton.setSelected(true);
+				showToggleButton.setToolTipText("Show Details");
+				showToggleButton.setIcon(new FlatSVGIcon("com/formdev/flatlaf/demo/icons/show.svg"));
+				toolBar.add(showToggleButton);
+			}
+			toolBarPanel.add(toolBar, BorderLayout.CENTER);
 		}
-		contentPane.add(toolBar, BorderLayout.NORTH);
+		contentPane.add(toolBarPanel, BorderLayout.NORTH);
 
 		//======== contentPanel ========
 		{
@@ -903,6 +920,70 @@ class DemoFrame
 		buttonGroup1.add(radioButtonMenuItem3);
 		// JFormDesigner - End of component initialization  //GEN-END:initComponents
 
+		//TODO remove
+		backButton.addActionListener( e -> {
+			rootPane.putClientProperty( FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING, FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING_LARGE );
+		});
+		forwardButton.addActionListener( e -> {
+			rootPane.putClientProperty( FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING, FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING_MEDIUM );
+		});
+		cutButton.addActionListener( e -> {
+			rootPane.putClientProperty( FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING, null );
+		});
+
+		copyButton.addActionListener( e -> System.out.println( e ) );
+		copyButton.addMouseListener( new MouseListener() {
+
+			@Override
+			public void mouseReleased( MouseEvent e ) {
+				// TODO Auto-generated method stub
+				System.out.println( "m release" );
+			}
+
+			@Override
+			public void mousePressed( MouseEvent e ) {
+				// TODO Auto-generated method stub
+				System.out.println( "m press" );
+			}
+
+			@Override
+			public void mouseExited( MouseEvent e ) {
+				// TODO Auto-generated method stub
+				System.out.println( "m exit" );
+			}
+
+			@Override
+			public void mouseEntered( MouseEvent e ) {
+				// TODO Auto-generated method stub
+				System.out.println( "m ent" );
+			}
+
+			@Override
+			public void mouseClicked( MouseEvent e ) {
+				// TODO Auto-generated method stub
+			System.out.println( "m click" );
+			}
+		} );
+		copyButton.addMouseMotionListener( new MouseMotionListener() {
+
+			@Override
+			public void mouseMoved( MouseEvent e ) {
+				// TODO Auto-generated method stub
+				System.out.println( "m moved" );
+			}
+
+			@Override
+			public void mouseDragged( MouseEvent e ) {
+				// TODO Auto-generated method stub
+				System.out.println( "m drag" );
+			}
+		} );
+		if( SystemInfo.isMacOS && FlatNativeMacLibrary.isLoaded() ) {
+			showToggleButton.addActionListener( e -> {
+				FlatNativeMacLibrary.toggleWindowFullScreen( this );
+			} );
+		}
+
 		// add "Users" button to menubar
 		FlatButton usersButton = new FlatButton();
 		usersButton.setIcon( new FlatSVGIcon( "com/formdev/flatlaf/demo/icons/users.svg" ) );
@@ -943,6 +1024,9 @@ class DemoFrame
 		if( "false".equals( System.getProperty( "flatlaf.animatedLafChange" ) ) )
 			animatedLafChangeMenuItem.setSelected( false );
 
+		// on macOS, panel left to toolBar is a placeholder for title bar buttons in fullWindowContent mode
+		macFullWindowContentButtonsPlaceholder.putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER, "mac zeroInFullScreen" );
+
 		// remove contentPanel bottom insets
 		MigLayout layout = (MigLayout) contentPanel.getLayout();
 		LC lc = ConstraintParser.parseLayoutConstraint( (String) layout.getLayoutConstraints() );

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

@@ -1,4 +1,4 @@
-JFDML JFormDesigner: "8.1.0.0.283" Java: "19.0.2" encoding: "UTF-8"
+JFDML JFormDesigner: "8.2.1.0.348" Java: "21.0.1" encoding: "UTF-8"
 
 new FormModel {
 	contentType: "form/swing"
@@ -12,56 +12,66 @@ new FormModel {
 			"defaultCloseOperation": 2
 			"$locationPolicy": 2
 			"$sizePolicy": 2
-			add( new FormContainer( "javax.swing.JToolBar", new FormLayoutManager( class javax.swing.JToolBar ) ) {
+			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class java.awt.BorderLayout ) ) {
-				name: "toolBar"
+				name: "toolBarPanel"
-				"margin": new java.awt.Insets( 3, 3, 3, 3 )
+				add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class java.awt.FlowLayout ) ) {
-				auxiliary() {
+					name: "macFullWindowContentButtonsPlaceholder"
-					"JavaCodeGenerator.variableLocal": false
+				}, new FormLayoutConstraints( class java.lang.String ) {
-				}
+					"value": "West"
-				add( new FormComponent( "javax.swing.JButton" ) {
-					name: "backButton"
-					"toolTipText": "Back"
-					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/back.svg" )
 				} )
-				add( new FormComponent( "javax.swing.JButton" ) {
+				add( new FormContainer( "javax.swing.JToolBar", new FormLayoutManager( class javax.swing.JToolBar ) ) {
-					name: "forwardButton"
+					name: "toolBar"
-					"toolTipText": "Forward"
+					"margin": new java.awt.Insets( 3, 3, 3, 3 )
-					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/forward.svg" )
+					auxiliary() {
-				} )
+						"JavaCodeGenerator.variableLocal": false
-				add( new FormComponent( "javax.swing.JToolBar$Separator" ) {
+					}
-					name: "separator5"
+					add( new FormComponent( "javax.swing.JButton" ) {
-				} )
+						name: "backButton"
-				add( new FormComponent( "javax.swing.JButton" ) {
+						"toolTipText": "Back"
-					name: "cutButton"
+						"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/back.svg" )
-					"toolTipText": "Cut"
+					} )
-					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/menu-cut.svg" )
+					add( new FormComponent( "javax.swing.JButton" ) {
-				} )
+						name: "forwardButton"
-				add( new FormComponent( "javax.swing.JButton" ) {
+						"toolTipText": "Forward"
-					name: "copyButton"
+						"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/forward.svg" )
-					"toolTipText": "Copy"
+					} )
-					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/copy.svg" )
+					add( new FormComponent( "javax.swing.JToolBar$Separator" ) {
-				} )
+						name: "separator5"
-				add( new FormComponent( "javax.swing.JButton" ) {
+					} )
-					name: "pasteButton"
+					add( new FormComponent( "javax.swing.JButton" ) {
-					"toolTipText": "Paste"
+						name: "cutButton"
-					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/menu-paste.svg" )
+						"toolTipText": "Cut"
-				} )
+						"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/menu-cut.svg" )
-				add( new FormComponent( "javax.swing.JToolBar$Separator" ) {
+					} )
-					name: "separator6"
+					add( new FormComponent( "javax.swing.JButton" ) {
-				} )
+						name: "copyButton"
-				add( new FormComponent( "javax.swing.JButton" ) {
+						"toolTipText": "Copy"
-					name: "refreshButton"
+						"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/copy.svg" )
-					"toolTipText": "Refresh"
+					} )
-					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/refresh.svg" )
+					add( new FormComponent( "javax.swing.JButton" ) {
-				} )
+						name: "pasteButton"
-				add( new FormComponent( "javax.swing.JToolBar$Separator" ) {
+						"toolTipText": "Paste"
-					name: "separator7"
+						"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/menu-paste.svg" )
-				} )
+					} )
-				add( new FormComponent( "javax.swing.JToggleButton" ) {
+					add( new FormComponent( "javax.swing.JToolBar$Separator" ) {
-					name: "showToggleButton"
+						name: "separator6"
-					"selected": true
+					} )
-					"toolTipText": "Show Details"
+					add( new FormComponent( "javax.swing.JButton" ) {
-					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/show.svg" )
+						name: "refreshButton"
+						"toolTipText": "Refresh"
+						"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/refresh.svg" )
+					} )
+					add( new FormComponent( "javax.swing.JToolBar$Separator" ) {
+						name: "separator7"
+					} )
+					add( new FormComponent( "javax.swing.JToggleButton" ) {
+						name: "showToggleButton"
+						"selected": true
+						"toolTipText": "Show Details"
+						"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/show.svg" )
+					} )
+				}, new FormLayoutConstraints( class java.lang.String ) {
+					"value": "Center"
 				} )
 			}, new FormLayoutConstraints( class java.lang.String ) {
 				"value": "North"

flatlaf-natives/flatlaf-natives-macos/src/main/headers/JNIUtils.h

@@ -41,4 +41,6 @@
 	}
 
 
-jfieldID getFieldID( JNIEnv *env, const char* className, const char* fieldName, const char* fieldSignature );
+jclass findClass( JNIEnv *env, const char* className, bool globalRef );
+jfieldID getFieldID( JNIEnv *env, const char* className, const char* fieldName, const char* fieldSignature, bool staticField );
+jmethodID getMethodID( JNIEnv *env, jclass cls, const char* methodName, const char* methodSignature, bool staticMethod );

flatlaf-natives/flatlaf-natives-macos/src/main/headers/com_formdev_flatlaf_ui_FlatNativeMacLibrary.h

@@ -7,6 +7,12 @@
 #ifdef __cplusplus
 extern "C" {
 #endif
+#undef com_formdev_flatlaf_ui_FlatNativeMacLibrary_BUTTONS_SPACING_DEFAULT
+#define com_formdev_flatlaf_ui_FlatNativeMacLibrary_BUTTONS_SPACING_DEFAULT 0L
+#undef com_formdev_flatlaf_ui_FlatNativeMacLibrary_BUTTONS_SPACING_MEDIUM
+#define com_formdev_flatlaf_ui_FlatNativeMacLibrary_BUTTONS_SPACING_MEDIUM 1L
+#undef com_formdev_flatlaf_ui_FlatNativeMacLibrary_BUTTONS_SPACING_LARGE
+#define com_formdev_flatlaf_ui_FlatNativeMacLibrary_BUTTONS_SPACING_LARGE 2L
 /*
  * Class:     com_formdev_flatlaf_ui_FlatNativeMacLibrary
  * Method:    setWindowRoundedBorder
@@ -15,6 +21,38 @@ extern "C" {
 JNIEXPORT jboolean JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_setWindowRoundedBorder
   (JNIEnv *, jclass, jobject, jfloat, jfloat, jint);
 
+/*
+ * Class:     com_formdev_flatlaf_ui_FlatNativeMacLibrary
+ * Method:    setWindowButtonsSpacing
+ * Signature: (Ljava/awt/Window;I)Z
+ */
+JNIEXPORT jboolean JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_setWindowButtonsSpacing
+  (JNIEnv *, jclass, jobject, jint);
+
+/*
+ * Class:     com_formdev_flatlaf_ui_FlatNativeMacLibrary
+ * Method:    getWindowButtonsBounds
+ * Signature: (Ljava/awt/Window;)Ljava/awt/Rectangle;
+ */
+JNIEXPORT jobject JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_getWindowButtonsBounds
+  (JNIEnv *, jclass, jobject);
+
+/*
+ * Class:     com_formdev_flatlaf_ui_FlatNativeMacLibrary
+ * Method:    isWindowFullScreen
+ * Signature: (Ljava/awt/Window;)Z
+ */
+JNIEXPORT jboolean JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_isWindowFullScreen
+  (JNIEnv *, jclass, jobject);
+
+/*
+ * Class:     com_formdev_flatlaf_ui_FlatNativeMacLibrary
+ * Method:    toggleWindowFullScreen
+ * Signature: (Ljava/awt/Window;)Z
+ */
+JNIEXPORT jboolean JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_toggleWindowFullScreen
+  (JNIEnv *, jclass, jobject);
+
 #ifdef __cplusplus
 }
 #endif

flatlaf-natives/flatlaf-natives-macos/src/main/objcpp/JNIUtils.mm

@@ -21,8 +21,8 @@
  * @author Karl Tauber
  */
 
-jfieldID getFieldID( JNIEnv *env, const char* className, const char* fieldName, const char* fieldSignature ) {
+jclass findClass( JNIEnv *env, const char* className, bool globalRef ) {
-//	NSLog( @"getFieldID %s %s %s", className, fieldName, fieldSignature );
+//	NSLog( @"findClass %s", className );
 
 	jclass cls = env->FindClass( className );
 	if( cls == NULL ) {
@@ -32,7 +32,22 @@ jfieldID getFieldID( JNIEnv *env, const char* className, const char* fieldName,
 		return NULL;
 	}
 
-	jfieldID fieldID = env->GetFieldID( cls, fieldName, fieldSignature );
+	if( globalRef )
+		cls = reinterpret_cast<jclass>( env->NewGlobalRef( cls ) );
+
+	return cls;
+}
+
+jfieldID getFieldID( JNIEnv *env, const char* className, const char* fieldName, const char* fieldSignature, bool staticField ) {
+//	NSLog( @"getFieldID %s %s %s", className, fieldName, fieldSignature );
+
+	jclass cls = findClass( env, className, false );
+	if( cls == NULL )
+		return NULL;
+
+	jfieldID fieldID = staticField
+		? env->GetStaticFieldID( cls, fieldName, fieldSignature )
+		: env->GetFieldID( cls, fieldName, fieldSignature );
 	if( fieldID == NULL ) {
 		NSLog( @"FlatLaf: failed to lookup field '%s' of type '%s' in class '%s'", fieldName, fieldSignature, className );
 		env->ExceptionDescribe(); // print stack trace
@@ -42,3 +57,22 @@ jfieldID getFieldID( JNIEnv *env, const char* className, const char* fieldName,
 
 	return fieldID;
 }
+
+jmethodID getMethodID( JNIEnv *env, jclass cls, const char* methodName, const char* methodSignature, bool staticMethod ) {
+//	NSLog( @"getMethodID %s %s", methodName, methodSignature );
+
+	if( cls == NULL )
+		return NULL;
+
+	jmethodID methodID = staticMethod
+		? env->GetStaticMethodID( cls, methodName, methodSignature )
+		: env->GetMethodID( cls, methodName, methodSignature );
+	if( methodID == NULL ) {
+		NSLog( @"FlatLaf: failed to lookup method '%s' of type '%s'", methodName, methodSignature );
+		env->ExceptionDescribe(); // print stack trace
+		env->ExceptionClear();
+		return NULL;
+	}
+
+	return methodID;
+}

flatlaf-natives/flatlaf-natives-macos/src/main/objcpp/MacWindow.mm

@@ -15,6 +15,7 @@
  */
 
 #import <Cocoa/Cocoa.h>
+#import <objc/runtime.h>
 #import <jni.h>
 #import "JNIUtils.h"
 #import "JNFRunLoop.h"
@@ -24,14 +25,37 @@
  * @author Karl Tauber
  */
 
+@interface WindowData : NSObject
+	// used when window is full screen
+	@property (nonatomic) int lastWindowButtonAreaWidth;
+	@property (nonatomic) int lastWindowTitleBarHeight;
+
+	// full screen observers
+	@property (nonatomic) id willEnterFullScreenObserver;
+	@property (nonatomic) id willExitFullScreenObserver;
+	@property (nonatomic) id didExitFullScreenObserver;
+@end
+
+@implementation WindowData
+@end
+
+// declare internal methods
+NSWindow* getNSWindow( JNIEnv* env, jclass cls, jobject window );
+WindowData* getWindowData( NSWindow* nsWindow, bool allocate );
+void setWindowButtonsHidden( NSWindow* nsWindow, bool hidden );
+int getWindowButtonAreaWidth( NSWindow* nsWindow );
+int getWindowTitleBarHeight( NSWindow* nsWindow );
+bool isWindowFullScreen( NSWindow* nsWindow );
+
+
 NSWindow* getNSWindow( JNIEnv* env, jclass cls, jobject window ) {
 	if( window == NULL )
 		return NULL;
 
-	// initialize field IDs (done only once because fields are static)
+	// initialize field IDs (done only once because variables are static)
-	static jfieldID peerID = getFieldID( env, "java/awt/Component", "peer", "Ljava/awt/peer/ComponentPeer;" );
+	static jfieldID peerID = getFieldID( env, "java/awt/Component", "peer", "Ljava/awt/peer/ComponentPeer;", false );
-	static jfieldID platformWindowID = getFieldID( env, "sun/lwawt/LWWindowPeer", "platformWindow", "Lsun/lwawt/PlatformWindow;" );
+	static jfieldID platformWindowID = getFieldID( env, "sun/lwawt/LWWindowPeer", "platformWindow", "Lsun/lwawt/PlatformWindow;", false );
-	static jfieldID ptrID = getFieldID( env, "sun/lwawt/macosx/CFRetainedResource", "ptr", "J" );
+	static jfieldID ptrID = getFieldID( env, "sun/lwawt/macosx/CFRetainedResource", "ptr", "J", false );
 	if( peerID == NULL || platformWindowID == NULL || ptrID == NULL )
 		return NULL;
 
@@ -49,6 +73,16 @@ NSWindow* getNSWindow( JNIEnv* env, jclass cls, jobject window ) {
 	return (NSWindow *) jlong_to_ptr( env->GetLongField( platformWindow, ptrID ) );
 }
 
+WindowData* getWindowData( NSWindow* nsWindow, bool allocate ) {
+	static char key;
+	WindowData* windowData = objc_getAssociatedObject( nsWindow, &key );
+	if( windowData == NULL && allocate ) {
+		windowData = [WindowData new];
+		objc_setAssociatedObject( nsWindow, &key, windowData, OBJC_ASSOCIATION_RETAIN_NONATOMIC );
+	}
+	return windowData;
+}
+
 extern "C"
 JNIEXPORT jboolean JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_setWindowRoundedBorder
 	( JNIEnv* env, jclass cls, jobject window, jfloat radius, jfloat borderWidth, jint borderColor )
@@ -87,3 +121,259 @@ JNIEXPORT jboolean JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_setW
 	JNI_COCOA_EXIT()
 	return FALSE;
 }
+
+extern "C"
+JNIEXPORT jboolean JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_setWindowButtonsSpacing
+	( JNIEnv* env, jclass cls, jobject window, jint buttonsSpacing )
+{
+	JNI_COCOA_ENTER()
+
+	NSWindow* nsWindow = getNSWindow( env, cls, window );
+	if( nsWindow == NULL )
+		return FALSE;
+
+	#define SPACING_DEFAULT com_formdev_flatlaf_ui_FlatNativeMacLibrary_BUTTONS_SPACING_DEFAULT
+	#define SPACING_MEDIUM  com_formdev_flatlaf_ui_FlatNativeMacLibrary_BUTTONS_SPACING_MEDIUM
+	#define SPACING_LARGE   com_formdev_flatlaf_ui_FlatNativeMacLibrary_BUTTONS_SPACING_LARGE
+
+	bool isMacOS_11_orLater = @available( macOS 11, * );
+	if( !isMacOS_11_orLater && buttonsSpacing == SPACING_LARGE )
+		buttonsSpacing = SPACING_MEDIUM;
+	int oldButtonsSpacing = (nsWindow.toolbar != NULL)
+		? ((isMacOS_11_orLater && nsWindow.toolbarStyle == NSWindowToolbarStyleUnified)
+			? SPACING_LARGE
+			: SPACING_MEDIUM)
+		: SPACING_DEFAULT;
+
+	if( buttonsSpacing == oldButtonsSpacing )
+		return TRUE;
+
+	WindowData* windowData = getWindowData( nsWindow, true );
+
+	[FlatJNFRunLoop performOnMainThreadWaiting:YES withBlock:^(){
+//		NSLog( @"\n%@\n\n", [nsWindow.contentView.superview _subtreeDescription] );
+
+		// add/remove toolbar
+		NSToolbar* toolbar = NULL;
+		bool needsToolbar = (buttonsSpacing != SPACING_DEFAULT);
+		if( needsToolbar ) {
+			toolbar = [NSToolbar new];
+			toolbar.showsBaselineSeparator = NO; // necessary for older macOS versions
+			if( isWindowFullScreen( nsWindow ) )
+				toolbar.visible = NO;
+		}
+		nsWindow.toolbar = toolbar;
+
+		if( isMacOS_11_orLater ) {
+			nsWindow.toolbarStyle = (buttonsSpacing == SPACING_LARGE)
+				? NSWindowToolbarStyleUnified
+				: (buttonsSpacing == SPACING_MEDIUM)
+					? NSWindowToolbarStyleUnifiedCompact
+					: NSWindowToolbarStyleAutomatic;
+		}
+
+		windowData.lastWindowButtonAreaWidth = 0;
+		windowData.lastWindowTitleBarHeight = 0;
+
+//		NSLog( @"\n%@\n\n", [nsWindow.contentView.superview _subtreeDescription] );
+
+		// when window becomes full screen, it is necessary to hide the toolbar
+		// because it otherwise is shown non-transparent and hides Swing components
+		NSNotificationCenter* center = [NSNotificationCenter defaultCenter];
+		if( needsToolbar && windowData.willEnterFullScreenObserver == NULL ) {
+//			NSLog( @"add observers %@", nsWindow );
+			windowData.willEnterFullScreenObserver = [center addObserverForName:NSWindowWillEnterFullScreenNotification
+				object:nsWindow queue:nil usingBlock:^(NSNotification *note) {
+//					NSLog( @"enter full screen %@", nsWindow );
+					if( nsWindow.toolbar != NULL ) {
+						// remember button area width, which is used later when window exits full screen
+						// remembar title bar height so that "main" JToolBar keeps its height in full screen
+						windowData.lastWindowButtonAreaWidth = getWindowButtonAreaWidth( nsWindow );
+						windowData.lastWindowTitleBarHeight = getWindowTitleBarHeight( nsWindow );
+//						NSLog( @"%d %d", windowData.lastWindowButtonAreaWidth, windowData.lastWindowTitleBarHeight );
+
+						nsWindow.toolbar.visible = NO;
+					}
+				}];
+
+			windowData.willExitFullScreenObserver = [center addObserverForName:NSWindowWillExitFullScreenNotification
+				object:nsWindow queue:nil usingBlock:^(NSNotification *note) {
+//					NSLog( @"will exit  full screen %@", nsWindow );
+					if( nsWindow.toolbar != NULL )
+						setWindowButtonsHidden( nsWindow, true );
+				}];
+
+			windowData.didExitFullScreenObserver = [center addObserverForName:NSWindowDidExitFullScreenNotification
+				object:nsWindow queue:nil usingBlock:^(NSNotification *note) {
+//					NSLog( @"exit  full screen %@", nsWindow );
+					if( nsWindow.toolbar != NULL ) {
+						setWindowButtonsHidden( nsWindow, false );
+						nsWindow.toolbar.visible = YES;
+					}
+
+					windowData.lastWindowButtonAreaWidth = 0;
+					windowData.lastWindowTitleBarHeight = 0;
+				}];
+		} else if( !needsToolbar ) {
+//			NSLog( @"remove observers %@", nsWindow );
+			if( windowData.willEnterFullScreenObserver != NULL ) {
+				[center removeObserver:windowData.willEnterFullScreenObserver];
+				windowData.willEnterFullScreenObserver = nil;
+			}
+			if( windowData.willExitFullScreenObserver != NULL ) {
+				[center removeObserver:windowData.willExitFullScreenObserver];
+				windowData.willExitFullScreenObserver = nil;
+			}
+			if( windowData.didExitFullScreenObserver != NULL ) {
+				[center removeObserver:windowData.didExitFullScreenObserver];
+				windowData.didExitFullScreenObserver = nil;
+			}
+		}
+	}];
+
+	return TRUE;
+
+	JNI_COCOA_EXIT()
+	return FALSE;
+}
+
+void setWindowButtonsHidden( NSWindow* nsWindow, bool hidden ) {
+	// get buttons
+	NSView* buttons[3] = {
+		[nsWindow standardWindowButton:NSWindowCloseButton],
+		[nsWindow standardWindowButton:NSWindowMiniaturizeButton],
+		[nsWindow standardWindowButton:NSWindowZoomButton]
+	};
+
+	for( int i = 0; i < 3; i++ ) {
+		NSView* button = buttons[i];
+		if( button != NULL )
+			button.hidden = hidden;
+	}
+}
+
+extern "C"
+JNIEXPORT jobject JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_getWindowButtonsBounds
+	( JNIEnv* env, jclass cls, jobject window )
+{
+	JNI_COCOA_ENTER()
+
+	NSWindow* nsWindow = getNSWindow( env, cls, window );
+	if( nsWindow == NULL )
+		return NULL;
+
+	WindowData* windowData = getWindowData( nsWindow, false );
+	int width = 0;
+	int height = 0;
+
+	// get width
+	if( isWindowFullScreen( nsWindow ) ) {
+		// use zero if window is full screen because close/minimize/zoom buttons are hidden
+		width = 0;
+	} else if( windowData != NULL && windowData.lastWindowButtonAreaWidth > 0 ) {
+		// use remembered value if window is in transition from full screen to non-full screen
+		// because NSToolbar is not yet visible
+		width = windowData.lastWindowButtonAreaWidth;
+	} else
+		width = getWindowButtonAreaWidth( nsWindow );
+
+	// get height
+	if( windowData != NULL && windowData.lastWindowTitleBarHeight > 0 ) {
+		// use remembered value if window is full screen because NSToolbar is hidden
+		height = windowData.lastWindowTitleBarHeight;
+	} else
+		height = getWindowTitleBarHeight( nsWindow );
+
+	// initialize class and method ID (done only once because variables are static)
+	static jclass cls = findClass( env, "java/awt/Rectangle", true );
+	static jmethodID methodID = getMethodID( env, cls, "<init>", "(IIII)V", false );
+	if( cls == NULL || methodID == NULL )
+		return NULL;
+
+	// create and return Rectangle
+	return env->NewObject( cls, methodID, 0, 0, width, height );
+
+	JNI_COCOA_EXIT()
+	return NULL;
+}
+
+int getWindowButtonAreaWidth( NSWindow* nsWindow ) {
+	// get buttons
+	NSView* buttons[3] = {
+		[nsWindow standardWindowButton:NSWindowCloseButton],
+		[nsWindow standardWindowButton:NSWindowMiniaturizeButton],
+		[nsWindow standardWindowButton:NSWindowZoomButton]
+	};
+
+	// get most left and right coordinates
+	int left = -1;
+	int right = -1;
+	for( int i = 0; i < 3; i++ ) {
+		NSView* button = buttons[i];
+		if( button == NULL )
+			continue;
+
+		int x = [button convertRect: [button bounds] toView:button.superview].origin.x;
+		int width = button.bounds.size.width;
+		if( left == -1 || x < left )
+			left = x;
+		if( right == -1 || x + width > right )
+			right = x + width;
+	}
+
+	if( left == -1 || right == -1 )
+		return -1;
+
+	// 'right' is the actual button area width (from left window edge)
+	// adding 'left' to add same empty space on right side as on left side
+	return right + left;
+}
+
+int getWindowTitleBarHeight( NSWindow* nsWindow ) {
+	NSView* closeButton = [nsWindow standardWindowButton:NSWindowCloseButton];
+	if( closeButton == NULL )
+		return -1;
+
+	NSView* titlebar = closeButton.superview;
+	return titlebar.bounds.size.height;
+}
+
+extern "C"
+JNIEXPORT jboolean JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_isWindowFullScreen
+	( JNIEnv* env, jclass cls, jobject window )
+{
+	JNI_COCOA_ENTER()
+
+	NSWindow* nsWindow = getNSWindow( env, cls, window );
+	if( nsWindow == NULL )
+		return FALSE;
+
+	return (jboolean) isWindowFullScreen( nsWindow );
+
+	JNI_COCOA_EXIT()
+	return FALSE;
+}
+
+bool isWindowFullScreen( NSWindow* nsWindow ) {
+	return ((nsWindow.styleMask & NSWindowStyleMaskFullScreen) != 0);
+}
+
+extern "C"
+JNIEXPORT jboolean JNICALL Java_com_formdev_flatlaf_ui_FlatNativeMacLibrary_toggleWindowFullScreen
+	( JNIEnv* env, jclass cls, jobject window )
+{
+	JNI_COCOA_ENTER()
+
+	NSWindow* nsWindow = getNSWindow( env, cls, window );
+	if( nsWindow == NULL )
+		return FALSE;
+
+	[FlatJNFRunLoop performOnMainThreadWaiting:NO withBlock:^(){
+		[nsWindow toggleFullScreen:nil];
+	}];
+
+	return TRUE;
+
+	JNI_COCOA_EXIT()
+	return FALSE;
+}

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatMacOSTest.java

@@ -0,0 +1,283 @@
+/*
+ * Copyright 2024 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.testing;
+
+import java.awt.*;
+import javax.swing.*;
+import com.formdev.flatlaf.FlatClientProperties;
+import com.formdev.flatlaf.ui.FlatNativeMacLibrary;
+import com.formdev.flatlaf.util.SystemInfo;
+import net.miginfocom.swing.*;
+
+/**
+ * @author Karl Tauber
+ */
+public class FlatMacOSTest
+	extends FlatTestPanel
+{
+	public static void main( String[] args ) {
+		SwingUtilities.invokeLater( () -> {
+			FlatTestFrame frame = FlatTestFrame.create( args, FlatMacOSTest.class.getSimpleName() );
+			frame.applyComponentOrientationToFrame = true;
+
+			JRootPane rootPane = frame.getRootPane();
+			rootPane.putClientProperty( "apple.awt.fullWindowContent", true );
+			rootPane.putClientProperty( "apple.awt.transparentTitleBar", true );
+			rootPane.putClientProperty( "apple.awt.windowTitleVisible", false );
+
+			frame.showFrame( FlatMacOSTest::new );
+		} );
+	}
+
+	FlatMacOSTest() {
+		initComponents();
+
+		if( SystemInfo.isMacFullWindowContentSupported ) {
+			fullWindowContentHint.setVisible( false );
+			transparentTitleBarHint.setVisible( false );
+		}
+		if( SystemInfo.isJava_17_orLater ) {
+			windowTitleVisibleHint.setVisible( false );
+			buttonsSpacingHint.setVisible( false );
+		}
+
+		placeholderPanel.putClientProperty( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_PLACEHOLDER, "mac zeroInFullScreen" );
+		UIManager.put( "FlatLaf.debug.panel.showPlaceholders", true );
+	}
+
+	@Override
+	public void addNotify() {
+		super.addNotify();
+
+		JRootPane rootPane = getRootPane();
+		fullWindowContentCheckBox.setSelected( FlatClientProperties.clientPropertyBoolean( rootPane, "apple.awt.fullWindowContent", false ) );
+		transparentTitleBarCheckBox.setSelected( FlatClientProperties.clientPropertyBoolean( rootPane, "apple.awt.transparentTitleBar", false ) );
+		windowTitleVisibleCheckBox.setSelected( FlatClientProperties.clientPropertyBoolean( rootPane, "apple.awt.windowTitleVisible", true ) );
+
+		rootPane.addPropertyChangeListener( FlatClientProperties.FULL_WINDOW_CONTENT_BUTTONS_BOUNDS, e -> {
+			Rectangle bounds = (Rectangle) e.getNewValue();
+			fullWindowContentButtonsBoundsField.setText( bounds2string( bounds ) );
+		} );
+		updateNativeButtonBounds();
+	}
+
+	private void fullWindowContentChanged() {
+		getRootPane().putClientProperty( "apple.awt.fullWindowContent", fullWindowContentCheckBox.isSelected() );
+	}
+
+	private void transparentTitleBarChanged() {
+		getRootPane().putClientProperty( "apple.awt.transparentTitleBar", transparentTitleBarCheckBox.isSelected() );
+	}
+
+	private void windowTitleVisibleChanged() {
+		getRootPane().putClientProperty( "apple.awt.windowTitleVisible", windowTitleVisibleCheckBox.isSelected() );
+	}
+
+	private void buttonsSpacingChanged() {
+		String buttonsSpacing = null;
+		if( buttonsSpacingMediumRadioButton.isSelected() )
+			buttonsSpacing = FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING_MEDIUM;
+		else if( buttonsSpacingLargeRadioButton.isSelected() )
+			buttonsSpacing = FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING_LARGE;
+
+		getRootPane().putClientProperty( FlatClientProperties.MACOS_WINDOW_BUTTONS_SPACING, buttonsSpacing );
+
+		updateNativeButtonBounds();
+	}
+
+	private void updateNativeButtonBounds() {
+		if( !FlatNativeMacLibrary.isLoaded() )
+			return;
+
+		Window window = SwingUtilities.windowForComponent( this );
+		Rectangle bounds = FlatNativeMacLibrary.getWindowButtonsBounds( window );
+		nativeButtonsBoundsField.setText( bounds2string( bounds ) );
+	}
+
+	private String bounds2string( Rectangle bounds ) {
+		return (bounds != null)
+			? bounds.width + ", " + bounds.height + "   @ " + bounds.x + ", " + bounds.y
+			: "null";
+	}
+
+	private void toggleFullScreen() {
+		if( !FlatNativeMacLibrary.isLoaded() )
+			return;
+
+		Window window = SwingUtilities.windowForComponent( this );
+		FlatNativeMacLibrary.toggleWindowFullScreen( window );
+	}
+
+	private void initComponents() {
+		// JFormDesigner - Component initialization - DO NOT MODIFY  //GEN-BEGIN:initComponents
+		JPanel panel1 = new JPanel();
+		placeholderPanel = new JPanel();
+		JPanel panel2 = new JPanel();
+		fullWindowContentCheckBox = new JCheckBox();
+		fullWindowContentHint = new JLabel();
+		transparentTitleBarCheckBox = new JCheckBox();
+		transparentTitleBarHint = new JLabel();
+		windowTitleVisibleCheckBox = new JCheckBox();
+		windowTitleVisibleHint = new JLabel();
+		JLabel buttonsSpacingLabel = new JLabel();
+		buttonsSpacingDefaultRadioButton = new JRadioButton();
+		buttonsSpacingMediumRadioButton = new JRadioButton();
+		buttonsSpacingLargeRadioButton = new JRadioButton();
+		buttonsSpacingHint = new JLabel();
+		JLabel fullWindowContentButtonsBoundsLabel = new JLabel();
+		fullWindowContentButtonsBoundsField = new JLabel();
+		JLabel nativeButtonsBoundsLabel = new JLabel();
+		nativeButtonsBoundsField = new JLabel();
+		JButton toggleFullScreenButton = new JButton();
+
+		//======== this ========
+		setLayout(new BorderLayout());
+
+		//======== panel1 ========
+		{
+			panel1.setLayout(new BorderLayout());
+
+			//======== placeholderPanel ========
+			{
+				placeholderPanel.setBackground(Color.green);
+				placeholderPanel.setLayout(new FlowLayout());
+			}
+			panel1.add(placeholderPanel, BorderLayout.WEST);
+		}
+		add(panel1, BorderLayout.PAGE_START);
+
+		//======== panel2 ========
+		{
+			panel2.setLayout(new MigLayout(
+				"ltr,insets dialog,hidemode 3",
+				// columns
+				"[left]" +
+				"[left]" +
+				"[left]" +
+				"[left]para" +
+				"[fill]",
+				// rows
+				"[]" +
+				"[]" +
+				"[]" +
+				"[fill]" +
+				"[]" +
+				"[]para" +
+				"[]"));
+
+			//---- fullWindowContentCheckBox ----
+			fullWindowContentCheckBox.setText("fullWindowContent");
+			fullWindowContentCheckBox.addActionListener(e -> fullWindowContentChanged());
+			panel2.add(fullWindowContentCheckBox, "cell 0 0");
+
+			//---- fullWindowContentHint ----
+			fullWindowContentHint.setText("requires Java 12, 11.0.8 or 8u292");
+			fullWindowContentHint.setForeground(Color.red);
+			panel2.add(fullWindowContentHint, "cell 4 0");
+
+			//---- transparentTitleBarCheckBox ----
+			transparentTitleBarCheckBox.setText("transparentTitleBar");
+			transparentTitleBarCheckBox.addActionListener(e -> transparentTitleBarChanged());
+			panel2.add(transparentTitleBarCheckBox, "cell 0 1");
+
+			//---- transparentTitleBarHint ----
+			transparentTitleBarHint.setText("requires Java 12, 11.0.8 or 8u292");
+			transparentTitleBarHint.setForeground(Color.red);
+			panel2.add(transparentTitleBarHint, "cell 4 1");
+
+			//---- windowTitleVisibleCheckBox ----
+			windowTitleVisibleCheckBox.setText("windowTitleVisible");
+			windowTitleVisibleCheckBox.addActionListener(e -> windowTitleVisibleChanged());
+			panel2.add(windowTitleVisibleCheckBox, "cell 0 2");
+
+			//---- windowTitleVisibleHint ----
+			windowTitleVisibleHint.setText("requires Java 17");
+			windowTitleVisibleHint.setForeground(Color.red);
+			panel2.add(windowTitleVisibleHint, "cell 4 2");
+
+			//---- buttonsSpacingLabel ----
+			buttonsSpacingLabel.setText("Buttons spacing:");
+			panel2.add(buttonsSpacingLabel, "cell 0 3");
+
+			//---- buttonsSpacingDefaultRadioButton ----
+			buttonsSpacingDefaultRadioButton.setText("Default");
+			buttonsSpacingDefaultRadioButton.setSelected(true);
+			buttonsSpacingDefaultRadioButton.addActionListener(e -> buttonsSpacingChanged());
+			panel2.add(buttonsSpacingDefaultRadioButton, "cell 1 3");
+
+			//---- buttonsSpacingMediumRadioButton ----
+			buttonsSpacingMediumRadioButton.setText("Medium");
+			buttonsSpacingMediumRadioButton.addActionListener(e -> buttonsSpacingChanged());
+			panel2.add(buttonsSpacingMediumRadioButton, "cell 2 3");
+
+			//---- buttonsSpacingLargeRadioButton ----
+			buttonsSpacingLargeRadioButton.setText("Large");
+			buttonsSpacingLargeRadioButton.addActionListener(e -> buttonsSpacingChanged());
+			panel2.add(buttonsSpacingLargeRadioButton, "cell 3 3");
+
+			//---- buttonsSpacingHint ----
+			buttonsSpacingHint.setText("requires Java 17");
+			buttonsSpacingHint.setForeground(Color.red);
+			panel2.add(buttonsSpacingHint, "cell 4 3");
+
+			//---- fullWindowContentButtonsBoundsLabel ----
+			fullWindowContentButtonsBoundsLabel.setText("Buttons bounds:");
+			panel2.add(fullWindowContentButtonsBoundsLabel, "cell 0 4");
+
+			//---- fullWindowContentButtonsBoundsField ----
+			fullWindowContentButtonsBoundsField.setText("null");
+			panel2.add(fullWindowContentButtonsBoundsField, "cell 1 4 3 1");
+
+			//---- nativeButtonsBoundsLabel ----
+			nativeButtonsBoundsLabel.setText("Native buttons bounds:");
+			panel2.add(nativeButtonsBoundsLabel, "cell 0 5");
+
+			//---- nativeButtonsBoundsField ----
+			nativeButtonsBoundsField.setText("null");
+			panel2.add(nativeButtonsBoundsField, "cell 1 5 3 1");
+
+			//---- toggleFullScreenButton ----
+			toggleFullScreenButton.setText("Toggle Full Screen");
+			toggleFullScreenButton.addActionListener(e -> toggleFullScreen());
+			panel2.add(toggleFullScreenButton, "cell 0 6");
+		}
+		add(panel2, BorderLayout.CENTER);
+
+		//---- buttonsSpacingButtonGroup ----
+		ButtonGroup buttonsSpacingButtonGroup = new ButtonGroup();
+		buttonsSpacingButtonGroup.add(buttonsSpacingDefaultRadioButton);
+		buttonsSpacingButtonGroup.add(buttonsSpacingMediumRadioButton);
+		buttonsSpacingButtonGroup.add(buttonsSpacingLargeRadioButton);
+		// JFormDesigner - End of component initialization  //GEN-END:initComponents
+	}
+
+	// JFormDesigner - Variables declaration - DO NOT MODIFY  //GEN-BEGIN:variables
+	private JPanel placeholderPanel;
+	private JCheckBox fullWindowContentCheckBox;
+	private JLabel fullWindowContentHint;
+	private JCheckBox transparentTitleBarCheckBox;
+	private JLabel transparentTitleBarHint;
+	private JCheckBox windowTitleVisibleCheckBox;
+	private JLabel windowTitleVisibleHint;
+	private JRadioButton buttonsSpacingDefaultRadioButton;
+	private JRadioButton buttonsSpacingMediumRadioButton;
+	private JRadioButton buttonsSpacingLargeRadioButton;
+	private JLabel buttonsSpacingHint;
+	private JLabel fullWindowContentButtonsBoundsField;
+	private JLabel nativeButtonsBoundsField;
+	// JFormDesigner - End of variables declaration  //GEN-END:variables
+}

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatMacOSTest.jfd

@@ -0,0 +1,191 @@
+JFDML JFormDesigner: "8.2.1.0.348" Java: "21.0.1" encoding: "UTF-8"
+
+new FormModel {
+	contentType: "form/swing"
+	root: new FormRoot {
+		auxiliary() {
+			"JavaCodeGenerator.defaultVariableLocal": true
+		}
+		add( new FormContainer( "com.formdev.flatlaf.testing.FlatTestPanel", new FormLayoutManager( class java.awt.BorderLayout ) ) {
+			name: "this"
+			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class java.awt.BorderLayout ) ) {
+				name: "panel1"
+				add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class java.awt.FlowLayout ) ) {
+					name: "placeholderPanel"
+					"background": sfield java.awt.Color green
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+				}, new FormLayoutConstraints( class java.lang.String ) {
+					"value": "West"
+				} )
+			}, new FormLayoutConstraints( class java.lang.String ) {
+				"value": "First"
+			} )
+			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
+				"$layoutConstraints": "ltr,insets dialog,hidemode 3"
+				"$columnConstraints": "[left][left][left][left]para[fill]"
+				"$rowConstraints": "[][][][fill][][]para[]"
+			} ) {
+				name: "panel2"
+				add( new FormComponent( "javax.swing.JCheckBox" ) {
+					name: "fullWindowContentCheckBox"
+					"text": "fullWindowContent"
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "fullWindowContentChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 0"
+				} )
+				add( new FormComponent( "javax.swing.JLabel" ) {
+					name: "fullWindowContentHint"
+					"text": "requires Java 12, 11.0.8 or 8u292"
+					"foreground": sfield java.awt.Color red
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 4 0"
+				} )
+				add( new FormComponent( "javax.swing.JCheckBox" ) {
+					name: "transparentTitleBarCheckBox"
+					"text": "transparentTitleBar"
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "transparentTitleBarChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 1"
+				} )
+				add( new FormComponent( "javax.swing.JLabel" ) {
+					name: "transparentTitleBarHint"
+					"text": "requires Java 12, 11.0.8 or 8u292"
+					"foreground": sfield java.awt.Color red
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 4 1"
+				} )
+				add( new FormComponent( "javax.swing.JCheckBox" ) {
+					name: "windowTitleVisibleCheckBox"
+					"text": "windowTitleVisible"
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "windowTitleVisibleChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 2"
+				} )
+				add( new FormComponent( "javax.swing.JLabel" ) {
+					name: "windowTitleVisibleHint"
+					"text": "requires Java 17"
+					"foreground": sfield java.awt.Color red
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 4 2"
+				} )
+				add( new FormComponent( "javax.swing.JLabel" ) {
+					name: "buttonsSpacingLabel"
+					"text": "Buttons spacing:"
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 3"
+				} )
+				add( new FormComponent( "javax.swing.JRadioButton" ) {
+					name: "buttonsSpacingDefaultRadioButton"
+					"text": "Default"
+					"$buttonGroup": new FormReference( "buttonsSpacingButtonGroup" )
+					"selected": true
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "buttonsSpacingChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 1 3"
+				} )
+				add( new FormComponent( "javax.swing.JRadioButton" ) {
+					name: "buttonsSpacingMediumRadioButton"
+					"text": "Medium"
+					"$buttonGroup": new FormReference( "buttonsSpacingButtonGroup" )
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "buttonsSpacingChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 2 3"
+				} )
+				add( new FormComponent( "javax.swing.JRadioButton" ) {
+					name: "buttonsSpacingLargeRadioButton"
+					"text": "Large"
+					"$buttonGroup": new FormReference( "buttonsSpacingButtonGroup" )
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "buttonsSpacingChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 3 3"
+				} )
+				add( new FormComponent( "javax.swing.JLabel" ) {
+					name: "buttonsSpacingHint"
+					"text": "requires Java 17"
+					"foreground": sfield java.awt.Color red
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 4 3"
+				} )
+				add( new FormComponent( "javax.swing.JLabel" ) {
+					name: "fullWindowContentButtonsBoundsLabel"
+					"text": "Buttons bounds:"
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 4"
+				} )
+				add( new FormComponent( "javax.swing.JLabel" ) {
+					name: "fullWindowContentButtonsBoundsField"
+					"text": "null"
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 1 4 3 1"
+				} )
+				add( new FormComponent( "javax.swing.JLabel" ) {
+					name: "nativeButtonsBoundsLabel"
+					"text": "Native buttons bounds:"
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 5"
+				} )
+				add( new FormComponent( "javax.swing.JLabel" ) {
+					name: "nativeButtonsBoundsField"
+					"text": "null"
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 1 5 3 1"
+				} )
+				add( new FormComponent( "javax.swing.JButton" ) {
+					name: "toggleFullScreenButton"
+					"text": "Toggle Full Screen"
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "toggleFullScreen", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 6"
+				} )
+			}, new FormLayoutConstraints( class java.lang.String ) {
+				"value": "Center"
+			} )
+		}, new FormLayoutConstraints( null ) {
+			"location": new java.awt.Point( 0, 0 )
+			"size": new java.awt.Dimension( 725, 350 )
+		} )
+		add( new FormNonVisual( "javax.swing.ButtonGroup" ) {
+			name: "buttonsSpacingButtonGroup"
+		}, new FormLayoutConstraints( null ) {
+			"location": new java.awt.Point( 0, 360 )
+		} )
+	}
+}