Title pane improvements (Windows 10 only)

CHANGELOG.md

@@ -5,10 +5,20 @@ FlatLaf Change Log
 
 #### New features and improvements
 
-- Native window decorations for Windows 10 enables dark frame/dialog title bar
-  and embedded menu bar with all JREs, while still having native Windows 10
-  border drop shadows, resize behavior, window snapping and system window menu.
-  (PR #267)
+- Windows 10 only:
+  - Native window decorations for Windows 10 enables dark frame/dialog title bar
+    and embedded menu bar with all JREs, while still having native Windows 10
+    border drop shadows, resize behavior, window snapping and system window
+    menu. (PR #267)
+  - Custom window decorations: Support right aligned components in `JFrame`
+    title bar with embedded menu bar (using `Box.createHorizontalGlue()`). (PR
+    #268)
+  - Custom window decorations: Improved centering of window title with embedded
+    menu bar. (PR #268; issue #252)
+  - Custom window decorations: Support unified backgrounds for window title bar,
+    menu bar and main content. If enabled with `UIManager.put(
+    "TitlePane.unifiedBackground", true );` then window title bar and menu bar
+    use same background color as main content. (PR #268; issue #254)
 
 #### Fixed bugs
 

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

@@ -16,17 +16,22 @@
 
 package com.formdev.flatlaf.ui;
 
+import java.awt.Graphics;
 import java.awt.event.ActionEvent;
 import javax.swing.AbstractAction;
 import javax.swing.ActionMap;
 import javax.swing.JComponent;
 import javax.swing.JMenu;
 import javax.swing.JMenuBar;
+import javax.swing.JRootPane;
+import javax.swing.LookAndFeel;
 import javax.swing.MenuElement;
 import javax.swing.MenuSelectionManager;
 import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
 import javax.swing.plaf.ActionMapUIResource;
 import javax.swing.plaf.ComponentUI;
+import javax.swing.plaf.UIResource;
 import javax.swing.plaf.basic.BasicMenuBarUI;
 import com.formdev.flatlaf.FlatLaf;
 import com.formdev.flatlaf.util.SystemInfo;
@@ -40,12 +45,15 @@
  * @uiDefault MenuBar.background						Color
  * @uiDefault MenuBar.foreground						Color
  * @uiDefault MenuBar.border							Border
+ * @uiDefault TitlePane.unifiedBackground				boolean
  *
  * @author Karl Tauber
  */
 public class FlatMenuBarUI
 	extends BasicMenuBarUI
 {
+	protected boolean unifiedBackground;
+
 	public static ComponentUI createUI( JComponent c ) {
 		return new FlatMenuBarUI();
 	}
@@ -55,6 +63,15 @@ public static ComponentUI createUI( JComponent c ) {
 	 *          Do not add any functionality here.
 	 */
 
+	@Override
+	protected void installDefaults() {
+		super.installDefaults();
+
+		LookAndFeel.installProperty( menuBar, "opaque", false );
+
+		unifiedBackground = UIManager.getBoolean( "TitlePane.unifiedBackground" );
+	}
+
 	@Override
 	protected void installKeyboardActions() {
 		super.installKeyboardActions();
@@ -67,6 +84,35 @@ protected void installKeyboardActions() {
 		map.put( "takeFocus", new TakeFocus() );
 	}
 
+	@Override
+	public void update( Graphics g, JComponent c ) {
+		// do not fill background if menubar is embedded into title pane
+		if( isFillBackground( c ) ) {
+			g.setColor( c.getBackground() );
+			g.fillRect( 0, 0, c.getWidth(), c.getHeight() );
+		}
+
+		paint( g, c );
+	}
+
+	protected boolean isFillBackground( JComponent c ) {
+		// paint background in opaque or having custom background color
+		if( c.isOpaque() || !(c.getBackground() instanceof UIResource) )
+			return true;
+
+		// do not paint background for unified title pane
+		if( unifiedBackground )
+			return false;
+
+		// paint background in full screen mode
+		JRootPane rootPane = SwingUtilities.getRootPane( c );
+		if( rootPane == null || FlatUIUtils.isFullScreen( rootPane ) )
+			return true;
+
+		// do not paint background if menu bar is embedded into title pane
+		return rootPane.getJMenuBar() != c || !FlatRootPaneUI.isMenuBarEmbedded( rootPane );
+	}
+
 	//---- class TakeFocus ----------------------------------------------------
 
 	/**

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

@@ -40,6 +40,7 @@
 import javax.swing.border.Border;
 import javax.swing.plaf.BorderUIResource;
 import javax.swing.plaf.ComponentUI;
+import javax.swing.plaf.RootPaneUI;
 import javax.swing.plaf.UIResource;
 import javax.swing.plaf.basic.BasicRootPaneUI;
 import com.formdev.flatlaf.FlatClientProperties;
@@ -227,6 +228,13 @@ public void propertyChange( PropertyChangeEvent e ) {
 		}
 	}
 
+	protected static boolean isMenuBarEmbedded( JRootPane rootPane ) {
+		RootPaneUI ui = rootPane.getUI();
+		return ui instanceof FlatRootPaneUI &&
+			((FlatRootPaneUI)ui).titlePane != null &&
+			((FlatRootPaneUI)ui).titlePane.isMenuBarEmbedded();
+	}
+
 	//---- class FlatRootLayout -----------------------------------------------
 
 	protected class FlatRootLayout
@@ -297,15 +305,16 @@ public void layoutContainer( Container parent ) {
 				rootPane.getGlassPane().setBounds( x, y, width, height );
 
 			int nextY = 0;
-			if( !isFullScreen && titlePane != null ) {
-				Dimension prefSize = titlePane.getPreferredSize();
-				titlePane.setBounds( 0, 0, width, prefSize.height );
-				nextY += prefSize.height;
+			if( titlePane != null ) {
+				int prefHeight = !isFullScreen ? titlePane.getPreferredSize().height : 0;
+				titlePane.setBounds( 0, 0, width, prefHeight );
+				nextY += prefHeight;
 			}
 
 			JMenuBar menuBar = rootPane.getJMenuBar();
 			if( menuBar != null && menuBar.isVisible() ) {
-				if( !isFullScreen && titlePane != null && titlePane.isMenuBarEmbedded() ) {
+				boolean embedded = !isFullScreen && titlePane != null && titlePane.isMenuBarEmbedded();
+				if( embedded ) {
 					titlePane.validate();
 					menuBar.setBounds( titlePane.getMenuBarBounds() );
 				} else {
@@ -342,6 +351,9 @@ public float getLayoutAlignmentY( Container target ) {
 
 	//---- class FlatWindowBorder ---------------------------------------------
 
+	/**
+	 * Window border used for non-native window decorations.
+	 */
 	public static class FlatWindowBorder
 		extends BorderUIResource.EmptyBorderUIResource
 	{
@@ -356,7 +368,7 @@ public FlatWindowBorder() {
 		@Override
 		public Insets getBorderInsets( Component c, Insets insets ) {
 			if( isWindowMaximized( c ) || FlatUIUtils.isFullScreen( c ) ) {
-				// hide border if window is maximized
+				// hide border if window is maximized or full screen
 				insets.top = insets.left = insets.bottom = insets.right = 0;
 				return insets;
 			} else