macOS window buttons spacing:

- renamed client property `MACOS_WINDOW_BUTTON_STYLE` to `MACOS_WINDOW_BUTTONS_SPACING`
- no longer allow value `true` for that client property
- enable using `MACOS_WINDOW_BUTTONS_SPACING` without `apple.awt.fullWindowContent`
- remove client property `FULL_WINDOW_CONTENT_BUTTONS_BOUNDS` when `apple.awt.fullWindowContent` is set to false or null
- added placeholder options `zeroInFullScreen`, `leftToRight` and `rightToLeft`
- hide close/min/max buttons during the transition from full-screen to non-full-screen to avoid that they "jump" when the nsToolbar is made visible
- fixed: full-screen listeners where added multiple times
- updated macOS native libraries
- added `FlatMacOSTest`

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

@@ -282,20 +282,24 @@ public interface FlatClientProperties
 	 * 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]"}.
+	 * 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 fullWindowContent mode
-	 * is supported on both platforms, you can add two placeholders to your layout
+	 * 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 {@code " horizontal"} or {@code " vertical"} to the value string
-	 * to specify that the placeholder preferred size should be limited to one orientation.
-	 * E.g. {@code "win horizontal"} means that the placeholder preferred width is
-	 * equal to iconfify/maximize/close buttons width, but preferred height is zero.
-	 * <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();
@@ -1350,41 +1354,39 @@ public interface FlatClientProperties
 	//---- macOS --------------------------------------------------------------
 
 	/**
-	 * Specifies the style of macOS window close/minimize/zoom buttons.
-	 * This does not change visual appearance but adds extra space around the buttons.
+	 * 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+ or 11+ for style 'large', Java 17+ and client property {@code apple.awt.fullWindowContent} set to {@code true})
+	 * (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} or {@link java.lang.Boolean}<br>
+	 * <strong>Value type</strong> {@link java.lang.String}<br>
 	 * <strong>Allowed Values</strong>
-	 *     {@link #MACOS_WINDOW_BUTTON_STYLE_MEDIUM},
-	 *     {@link #MACOS_WINDOW_BUTTON_STYLE_LARGE} (requires macOS 11+) or
-	 *     {@code true} (equal to 'large')
+	 *     {@link #MACOS_WINDOW_BUTTONS_SPACING_MEDIUM} or
+	 *     {@link #MACOS_WINDOW_BUTTONS_SPACING_LARGE} (requires macOS 11+)
 	 *
-	 * @since 3.3
+	 * @since 3.4
 	 */
-	String MACOS_WINDOW_BUTTON_STYLE = "FlatLaf.macOS.windowButtonStyle";
+	String MACOS_WINDOW_BUTTONS_SPACING = "FlatLaf.macOS.windowButtonsSpacing";
 
 	/**
-	 * Add medium space around the macOS window close/minimize/zoom buttons.
+	 * Add medium spacing around the macOS window close/minimize/zoom buttons.
 	 *
-	 * @see #MACOS_WINDOW_BUTTON_STYLE
-	 * @since 3.3
+	 * @see #MACOS_WINDOW_BUTTONS_SPACING
+	 * @since 3.4
 	 */
-	String MACOS_WINDOW_BUTTON_STYLE_MEDIUM = "medium";
+	String MACOS_WINDOW_BUTTONS_SPACING_MEDIUM = "medium";
 
 	/**
-	 * Add large space around the macOS window close/minimize/zoom buttons.
+	 * Add large spacing around the macOS window close/minimize/zoom buttons.
 	 * <p>
-	 * (requires macOS 11+; 'medium' is used on older systems)
+	 * (requires macOS 11+; "medium" is used on older systems)
 	 *
-	 * @see #MACOS_WINDOW_BUTTON_STYLE
-	 * @since 3.3
+	 * @see #MACOS_WINDOW_BUTTONS_SPACING
+	 * @since 3.4
 	 */
-	String MACOS_WINDOW_BUTTON_STYLE_LARGE = "large";
+	String MACOS_WINDOW_BUTTONS_SPACING_LARGE = "large";
 
 
 	//---- helper methods -----------------------------------------------------

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

@@ -18,6 +18,7 @@ package com.formdev.flatlaf.ui;
 
 import java.awt.Rectangle;
 import java.awt.Window;
+import com.formdev.flatlaf.util.SystemInfo;
 
 /**
  * Native methods for macOS.
@@ -50,18 +51,18 @@ 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
-		BUTTON_STYLE_DEFAULT = 0,
-		BUTTON_STYLE_MEDIUM = 1,
-		BUTTON_STYLE_LARGE = 2;
+		BUTTONS_SPACING_DEFAULT = 0,
+		BUTTONS_SPACING_MEDIUM = 1,
+		BUTTONS_SPACING_LARGE = 2;
 
-	/** @since 3.4 */ public native static boolean setWindowButtonStyle( Window window, int buttonStyle );
+	/** @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/FlatRootPaneUI.java

@@ -381,35 +381,49 @@ public class FlatRootPaneUI
 					throw new IllegalComponentStateException( "The client property 'Window.style' must be set before the window becomes displayable." );
 				break;
 
-			case FlatClientProperties.MACOS_WINDOW_BUTTON_STYLE:
 			case "ancestor":
-				if( SystemInfo.isMacFullWindowContentSupported &&
-					rootPane.isDisplayable() &&
-					FlatClientProperties.clientPropertyBoolean( rootPane, "apple.awt.fullWindowContent", false ) )
-				{
-					// set window button style
-					if( SystemInfo.isJava_17_orLater && FlatNativeMacLibrary.isLoaded() ) {
-						int buttonStyle = FlatNativeMacLibrary.BUTTON_STYLE_DEFAULT;
-						Object value = rootPane.getClientProperty( FlatClientProperties.MACOS_WINDOW_BUTTON_STYLE );
-						switch( String.valueOf( value ) ) {
-							case FlatClientProperties.MACOS_WINDOW_BUTTON_STYLE_MEDIUM:
-								buttonStyle = FlatNativeMacLibrary.BUTTON_STYLE_MEDIUM;
-								break;
+				// 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;
 
-							case "true":
-							case FlatClientProperties.MACOS_WINDOW_BUTTON_STYLE_LARGE:
-								buttonStyle = FlatNativeMacLibrary.BUTTON_STYLE_LARGE;
-								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.setWindowButtonStyle( window, buttonStyle );
+						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

@@ -48,32 +48,41 @@ class FullWindowContentSupport
 		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 )
-		{
-			// 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;
-			}
+		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( "horizontal" ) )
-					return new Dimension( bounds.width, 0 );
-				if( options.contains( "vertical" ) )
-					return new Dimension( 0, bounds.height );
-			}
-
-			return bounds.getSize();
+		if( options.length() > 3 ) {
+			if( (options.contains( "leftToRight" ) && !c.getComponentOrientation().isLeftToRight()) ||
+				(options.contains( "rightToLeft" ) && c.getComponentOrientation().isLeftToRight()) )
+			  return new Dimension( 0, 0 );
 		}
 
-		// default to 0,0
-		return new Dimension();
+		// 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 ) {
@@ -151,14 +160,15 @@ class FullWindowContentSupport
 	}
 
 	static void macUpdateFullWindowContentButtonsBoundsProperty( JRootPane rootPane ) {
-		if( !SystemInfo.isMacFullWindowContentSupported ||
-			!rootPane.isDisplayable() ||
-			!FlatClientProperties.clientPropertyBoolean( rootPane, "apple.awt.fullWindowContent", false ) )
-		  return;
+		if( !SystemInfo.isMacFullWindowContentSupported || !rootPane.isDisplayable() )
+			return;
 
-		Rectangle bounds = FlatNativeMacLibrary.isLoaded()
-			? FlatNativeMacLibrary.getWindowButtonsBounds( SwingUtilities.windowForComponent( rootPane ) )
-			: new Rectangle( 68, 28 ); // default size
+		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 );
 	}
 
@@ -166,18 +176,35 @@ class FullWindowContentSupport
 		if( !UIManager.getBoolean( KEY_DEBUG_SHOW_PLACEHOLDERS ) )
 			return;
 
-		int width = c.getWidth() - 1;
-		int height = c.getHeight() - 1;
+		int width = c.getWidth();
+		int height = c.getHeight();
 		if( width <= 0 || height <= 0 )
 			return;
 
+		// draw red figure
 		g.setColor( Color.red );
-		g.drawRect( 0, 0, width, height );
+		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( 0, 0, width, height );
-		g.drawLine( 0, height, width, 0 );
+		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 );
 	}
 }