Styling: Menu: support top-level underline selection

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

@@ -18,6 +18,7 @@ package com.formdev.flatlaf.ui;
 
 import java.awt.Color;
 import java.awt.Graphics;
+import java.awt.Insets;
 import java.awt.Window;
 import java.awt.event.ActionEvent;
 import java.beans.PropertyChangeListener;
@@ -40,6 +41,7 @@ import javax.swing.plaf.UIResource;
 import javax.swing.plaf.basic.BasicMenuBarUI;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.FlatLaf;
+import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
 import com.formdev.flatlaf.util.SystemInfo;
 
@@ -63,6 +65,15 @@ public class FlatMenuBarUI
 	extends BasicMenuBarUI
 	implements StyleableUI
 {
+	// used in FlatMenuItemBorder
+	/** @since 2 */ @Styleable protected Insets itemMargins;
+
+	// used in FlatMenuUI
+	/** @since 2 */ @Styleable protected Color hoverBackground;
+	/** @since 2 */ @Styleable protected Color underlineSelectionBackground;
+	/** @since 2 */ @Styleable protected Color underlineSelectionColor;
+	/** @since 2 */ @Styleable protected int underlineSelectionHeight = -1;
+
 	private PropertyChangeListener propertyChangeListener;
 	private Map<String, Object> oldStyleValues;
 	private AtomicBoolean borderShared;

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

@@ -18,9 +18,11 @@ package com.formdev.flatlaf.ui;
 
 import static com.formdev.flatlaf.util.UIScale.scale;
 import java.awt.Component;
+import java.awt.Container;
 import java.awt.Insets;
 import javax.swing.JMenuBar;
 import javax.swing.UIManager;
+import javax.swing.plaf.MenuBarUI;
 
 /**
  * Border for {@link javax.swing.JMenu}, {@link javax.swing.JMenuItem},
@@ -33,15 +35,22 @@ import javax.swing.UIManager;
 public class FlatMenuItemBorder
 	extends FlatMarginBorder
 {
+	// only used if parent menubar is not a instance of FlatMenuBarUI
 	private final Insets menuBarItemMargins = UIManager.getInsets( "MenuBar.itemMargins" );
 
 	@Override
 	public Insets getBorderInsets( Component c, Insets insets ) {
-		if( c.getParent() instanceof JMenuBar ) {
+		Container parent = c.getParent();
-			insets.top = scale( menuBarItemMargins.top );
+		if( parent instanceof JMenuBar ) {
-			insets.left = scale( menuBarItemMargins.left );
+			// get margins from FlatMenuBarUI to allow styling
-			insets.bottom = scale( menuBarItemMargins.bottom );
+			MenuBarUI ui = ((JMenuBar)parent).getUI();
-			insets.right = scale( menuBarItemMargins.right );
+			Insets margins = (ui instanceof FlatMenuBarUI && ((FlatMenuBarUI)ui).itemMargins != null)
+				? ((FlatMenuBarUI)ui).itemMargins
+				: this.menuBarItemMargins;
+			insets.top = scale( margins.top );
+			insets.left = scale( margins.left );
+			insets.bottom = scale( margins.bottom );
+			insets.right = scale( margins.right );
 			return insets;
 		} else
 			return super.getBorderInsets( c, insets );

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

@@ -23,15 +23,18 @@ import java.awt.Graphics;
 import java.awt.event.MouseEvent;
 import java.beans.PropertyChangeListener;
 import java.util.Map;
+import java.util.function.Function;
 import javax.swing.ButtonModel;
 import javax.swing.Icon;
 import javax.swing.JComponent;
 import javax.swing.JMenu;
+import javax.swing.JMenuBar;
 import javax.swing.JMenuItem;
 import javax.swing.LookAndFeel;
 import javax.swing.UIManager;
 import javax.swing.event.MouseInputListener;
 import javax.swing.plaf.ComponentUI;
+import javax.swing.plaf.MenuBarUI;
 import javax.swing.plaf.basic.BasicMenuUI;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
 import com.formdev.flatlaf.ui.FlatStylingSupport.UnknownStyleException;
@@ -64,10 +67,10 @@ import com.formdev.flatlaf.ui.FlatStylingSupport.UnknownStyleException;
  * <!-- FlatMenuUI -->
  *
  * @uiDefault MenuItem.iconTextGap									int
- * @uiDefault MenuBar.hoverBackground								Color
  *
  * <!-- FlatMenuRenderer -->
  *
+ * @uiDefault MenuBar.hoverBackground								Color
  * @uiDefault MenuBar.underlineSelectionBackground					Color
  * @uiDefault MenuBar.underlineSelectionColor						Color
  * @uiDefault MenuBar.underlineSelectionHeight						int
@@ -78,7 +81,6 @@ public class FlatMenuUI
 	extends BasicMenuUI
 	implements StyleableUI
 {
-	private Color hoverBackground;
 	private FlatMenuItemRenderer renderer;
 	private Map<String, Object> oldStyleValues;
 
@@ -101,7 +103,6 @@ public class FlatMenuUI
 
 		menuItem.setRolloverEnabled( true );
 
-		hoverBackground = UIManager.getColor( "MenuBar.hoverBackground" );
 		renderer = createRenderer();
 	}
 
@@ -109,7 +110,6 @@ public class FlatMenuUI
 	protected void uninstallDefaults() {
 		super.uninstallDefaults();
 
-		hoverBackground = null;
 		renderer = null;
 		oldStyleValues = null;
 	}
@@ -200,9 +200,10 @@ public class FlatMenuUI
 	protected class FlatMenuRenderer
 		extends FlatMenuItemRenderer
 	{
-		protected final Color menuBarUnderlineSelectionBackground = FlatUIUtils.getUIColor( "MenuBar.underlineSelectionBackground", underlineSelectionBackground );
+		protected Color hoverBackground = UIManager.getColor( "MenuBar.hoverBackground" );
-		protected final Color menuBarUnderlineSelectionColor = FlatUIUtils.getUIColor( "MenuBar.underlineSelectionColor", underlineSelectionColor );
+		protected Color menuBarUnderlineSelectionBackground = FlatUIUtils.getUIColor( "MenuBar.underlineSelectionBackground", underlineSelectionBackground );
-		protected final int menuBarUnderlineSelectionHeight = FlatUIUtils.getUIInt( "MenuBar.underlineSelectionHeight", underlineSelectionHeight );
+		protected Color menuBarUnderlineSelectionColor = FlatUIUtils.getUIColor( "MenuBar.underlineSelectionColor", underlineSelectionColor );
+		protected int menuBarUnderlineSelectionHeight = FlatUIUtils.getUIInt( "MenuBar.underlineSelectionHeight", underlineSelectionHeight );
 
 		protected FlatMenuRenderer( JMenuItem menuItem, Icon checkIcon, Icon arrowIcon,
 			Font acceleratorFont, String acceleratorDelimiter )
@@ -212,27 +213,39 @@ public class FlatMenuUI
 
 		@Override
 		protected void paintBackground( Graphics g, Color selectionBackground ) {
-			if( isUnderlineSelection() && ((JMenu)menuItem).isTopLevelMenu() )
+			if( ((JMenu)menuItem).isTopLevelMenu() ) {
-				selectionBackground = menuBarUnderlineSelectionBackground;
+				if( isUnderlineSelection() )
+					selectionBackground = getStyleFromMenuBarUI( ui -> ui.underlineSelectionBackground, menuBarUnderlineSelectionBackground );
 
-			ButtonModel model = menuItem.getModel();
+				ButtonModel model = menuItem.getModel();
-			if( model.isRollover() && !model.isArmed() && !model.isSelected() &&
+				if( model.isRollover() && !model.isArmed() && !model.isSelected() && model.isEnabled() ) {
-				model.isEnabled() && ((JMenu)menuItem).isTopLevelMenu() )
+					g.setColor( deriveBackground( getStyleFromMenuBarUI( ui -> ui.hoverBackground, hoverBackground ) ) );
-			{
+					g.fillRect( 0, 0, menuItem.getWidth(), menuItem.getHeight() );
-				g.setColor( deriveBackground( hoverBackground ) );
+					return;
-				g.fillRect( 0, 0, menuItem.getWidth(), menuItem.getHeight() );
+				}
-			} else
+			}
-				super.paintBackground( g, selectionBackground );
+
+			super.paintBackground( g, selectionBackground );
 		}
 
 		@Override
 		protected void paintUnderlineSelection( Graphics g, Color underlineSelectionColor, int underlineSelectionHeight ) {
 			if( ((JMenu)menuItem).isTopLevelMenu() ) {
-				underlineSelectionColor = menuBarUnderlineSelectionColor;
+				underlineSelectionColor = getStyleFromMenuBarUI( ui -> ui.underlineSelectionColor, menuBarUnderlineSelectionColor );
-				underlineSelectionHeight = menuBarUnderlineSelectionHeight;
+				underlineSelectionHeight = getStyleFromMenuBarUI( ui -> (ui.underlineSelectionHeight != -1)
+					? ui.underlineSelectionHeight : null, menuBarUnderlineSelectionHeight );
 			}
 
 			super.paintUnderlineSelection( g, underlineSelectionColor, underlineSelectionHeight );
 		}
+
+		private <T> T getStyleFromMenuBarUI( Function<FlatMenuBarUI, T> f, T defaultValue ) {
+			MenuBarUI ui = ((JMenuBar)menuItem.getParent()).getUI();
+			if( !(ui instanceof FlatMenuBarUI) )
+				return defaultValue;
+
+			T value = f.apply( (FlatMenuBarUI) ui );
+			return (value != null) ? value : defaultValue;
+		}
 	}
 }

flatlaf-core/src/test/java/com/formdev/flatlaf/ui/TestFlatStyleableInfo.java

@@ -264,6 +264,12 @@ public class TestFlatStyleableInfo
 		FlatMenuBarUI ui = (FlatMenuBarUI) c.getUI();
 
 		Map<String, Class<?>> expected = expectedMap(
+			"itemMargins", Insets.class,
+			"hoverBackground", Color.class,
+			"underlineSelectionBackground", Color.class,
+			"underlineSelectionColor", Color.class,
+			"underlineSelectionHeight", int.class,
+
 			// FlatMenuBarBorder
 			"borderColor", Color.class
 		);

flatlaf-core/src/test/java/com/formdev/flatlaf/ui/TestFlatStyling.java

@@ -362,6 +362,12 @@ public class TestFlatStyling
 		JMenuBar c = new JMenuBar();
 		FlatMenuBarUI ui = (FlatMenuBarUI) c.getUI();
 
+		ui.applyStyle( "itemMargins: 1,2,3,4" );
+		ui.applyStyle( "hoverBackground: #fff" );
+		ui.applyStyle( "underlineSelectionBackground: #fff" );
+		ui.applyStyle( "underlineSelectionColor: #fff" );
+		ui.applyStyle( "underlineSelectionHeight: 3" );
+
 		// FlatMenuBarBorder
 		ui.applyStyle( "borderColor: #fff" );