Merge PR #490: Menus: improved usability of submenus

CHANGELOG.md

@@ -5,6 +5,7 @@ FlatLaf Change Log
 
 #### New features and improvements
 
+- Menus: Improved usability of submenus. (PR #490; issue #247)
 - Linux: Support using custom window decorations. Enable with
   `JFrame.setDefaultLookAndFeelDecorated(true)` and
   `JDialog.setDefaultLookAndFeelDecorated(true)` before creating a window.

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

@@ -103,6 +103,7 @@ public abstract class FlatLaf
 
 	private PopupFactory oldPopupFactory;
 	private MnemonicHandler mnemonicHandler;
+	private SubMenuUsabilityHelper subMenuUsabilityHelper;
 
 	private Consumer<UIDefaults> postInitialization;
 	private List<Function<Object, Object>> uiDefaultsGetters;
@@ -244,6 +245,10 @@ public abstract class FlatLaf
 		mnemonicHandler = new MnemonicHandler();
 		mnemonicHandler.install();
 
+		// install submenu usability helper
+		subMenuUsabilityHelper = new SubMenuUsabilityHelper();
+		subMenuUsabilityHelper.install();
+
 		// listen to desktop property changes to update UI if system font or scaling changes
 		if( SystemInfo.isWindows ) {
 			// Windows 10 allows increasing font size independent of scaling:
@@ -323,6 +328,12 @@ public abstract class FlatLaf
 			mnemonicHandler = null;
 		}
 
+		// uninstall submenu usability helper
+		if( subMenuUsabilityHelper != null ) {
+			subMenuUsabilityHelper.uninstall();
+			subMenuUsabilityHelper = null;
+		}
+
 		// restore default link color
 		new HTMLEditorKit().getStyleSheet().addRule( "a, address { color: blue; }" );
 		postInitialization = null;

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

@@ -0,0 +1,316 @@
+/*
+ * Copyright 2022 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;
+
+import java.awt.AWTEvent;
+import java.awt.Color;
+import java.awt.Component;
+import java.awt.Container;
+import java.awt.Dimension;
+import java.awt.EventQueue;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.MouseInfo;
+import java.awt.Point;
+import java.awt.PointerInfo;
+import java.awt.Polygon;
+import java.awt.Rectangle;
+import java.awt.Toolkit;
+import java.awt.Window;
+import java.awt.event.MouseEvent;
+import javax.swing.JComponent;
+import javax.swing.JLayeredPane;
+import javax.swing.JMenu;
+import javax.swing.JPopupMenu;
+import javax.swing.MenuElement;
+import javax.swing.MenuSelectionManager;
+import javax.swing.RootPaneContainer;
+import javax.swing.SwingUtilities;
+import javax.swing.Timer;
+import javax.swing.UIManager;
+import javax.swing.event.ChangeEvent;
+import javax.swing.event.ChangeListener;
+import com.formdev.flatlaf.ui.FlatUIUtils;
+
+/**
+ * Improves usability of submenus by using a
+ * <a href="https://height.app/blog/guide-to-build-context-menus#safe-triangle">safe triangle</a>
+ * to avoid that the submenu closes while the user moves the mouse to it.
+ *
+ * @author Karl Tauber
+ */
+class SubMenuUsabilityHelper
+	implements ChangeListener
+{
+	private static final String KEY_USE_SAFE_TRIANGLE = "Menu.useSafeTriangle";
+	private static final String KEY_SHOW_SAFE_TRIANGLE = "FlatLaf.debug.menu.showSafeTriangle";
+
+	private SubMenuEventQueue subMenuEventQueue;
+	private SafeTrianglePainter safeTrianglePainter;
+	private boolean changePending;
+
+	// mouse location in screen coordinates
+	private int mouseX;
+	private int mouseY;
+
+	// target popup bounds in screen coordinates
+	private int targetX;
+	private int targetTopY;
+	private int targetBottomY;
+
+	private Rectangle invokerBounds;
+
+	void install() {
+		MenuSelectionManager.defaultManager().addChangeListener( this );
+	}
+
+	void uninstall() {
+		MenuSelectionManager.defaultManager().removeChangeListener( this );
+		uninstallEventQueue();
+	}
+
+	@Override
+	public void stateChanged( ChangeEvent e ) {
+		if( !FlatUIUtils.getUIBoolean( KEY_USE_SAFE_TRIANGLE, true ))
+			return;
+
+		// handle menu selection change later, but only once in case of temporary changes
+		// e.g. moving mouse from one menu item to another one, fires two events:
+		//    1. old menu item is removed from menu selection
+		//    2. new menu item is added to menu selection
+		synchronized( this ) {
+			if( changePending )
+				return;
+			changePending = true;
+		}
+
+		EventQueue.invokeLater( () -> {
+			synchronized( this ) {
+				changePending = false;
+			}
+			menuSelectionChanged();
+		} );
+	}
+
+	private void menuSelectionChanged() {
+		MenuElement[] path = MenuSelectionManager.defaultManager().getSelectedPath();
+
+/*debug
+		System.out.println( "--- " + path.length );
+		for( int i = 0; i < path.length; i++ )
+			System.out.println( "   " + i + ": " + path[i].getClass().getName() );
+debug*/
+
+		// find submenu in menu selection
+		int subMenuIndex = findSubMenu( path );
+
+		// uninstall if there is no submenu in selection
+		if( subMenuIndex < 0 || subMenuIndex != path.length - 1 ) {
+			uninstallEventQueue();
+			return;
+		}
+
+		// get current mouse location
+		PointerInfo pointerInfo = MouseInfo.getPointerInfo();
+		Point mouseLocation = (pointerInfo != null) ? pointerInfo.getLocation() : new Point();
+		mouseX = mouseLocation.x;
+		mouseY = mouseLocation.y;
+
+		// get invoker screen bounds
+		JPopupMenu popup = (JPopupMenu) path[subMenuIndex];
+		Component invoker = popup.getInvoker();
+		invokerBounds = (invoker != null)
+			? new Rectangle( invoker.getLocationOnScreen(), invoker.getSize() )
+			: null;
+
+		// check whether mouse location is within invoker
+		if( invokerBounds != null && !invokerBounds.contains( mouseX, mouseY ) ) {
+			uninstallEventQueue();
+			return;
+		}
+
+		// compute top/bottom target locations
+		Point popupLocation = popup.getLocationOnScreen();
+		Dimension popupSize = popup.getSize();
+		targetX = (mouseX < popupLocation.x + (popupSize.width / 2))
+			? popupLocation.x
+			: popupLocation.x + popupSize.width;
+		targetTopY = popupLocation.y;
+		targetBottomY = popupLocation.y + popupSize.height;
+
+		// install own event queue to supress mouse events when mouse is moved within safe triangle
+		if( subMenuEventQueue == null )
+			subMenuEventQueue = new SubMenuEventQueue();
+
+		// create safe triangle painter
+		if( safeTrianglePainter == null && UIManager.getBoolean( KEY_SHOW_SAFE_TRIANGLE ) )
+			safeTrianglePainter = new SafeTrianglePainter( popup );
+	}
+
+	private void uninstallEventQueue() {
+		if( subMenuEventQueue != null ) {
+			subMenuEventQueue.uninstall();
+			subMenuEventQueue = null;
+		}
+
+		if( safeTrianglePainter != null ) {
+			safeTrianglePainter.uninstall();
+			safeTrianglePainter = null;
+		}
+	}
+
+	private int findSubMenu( MenuElement[] path ) {
+		for( int i = path.length - 1; i >= 1; i-- ) {
+			if( path[i] instanceof JPopupMenu &&
+				path[i - 1] instanceof JMenu &&
+				!((JMenu)path[i - 1]).isTopLevelMenu() )
+			  return i;
+		}
+		return -1;
+	}
+
+	private Polygon createSafeTriangle() {
+		return new Polygon(
+			new int[] { mouseX, targetX, targetX },
+			new int[] { mouseY, targetTopY, targetBottomY },
+			3 );
+	}
+
+	//---- class SubMenuEventQueue --------------------------------------------
+
+	private class SubMenuEventQueue
+		extends EventQueue
+	{
+		private Timer mouseUpdateTimer;
+		private Timer timeoutTimer;
+
+		private int newMouseX;
+		private int newMouseY;
+		private AWTEvent lastMouseEvent;
+
+		SubMenuEventQueue() {
+			// timer used to slightly delay update of mouse location used for safe triangle
+			mouseUpdateTimer = new Timer( 50, e -> {
+				mouseX = newMouseX;
+				mouseY = newMouseY;
+
+				if( safeTrianglePainter != null )
+					safeTrianglePainter.repaint();
+			} );
+			mouseUpdateTimer.setRepeats( false );
+
+			// timer used to timeout safe triangle when mouse stops moving
+			timeoutTimer = new Timer( 200, e -> {
+				if( invokerBounds != null && !invokerBounds.contains( newMouseX, newMouseY ) ) {
+					// post last mouse event, which selects menu item at mouse location
+					if( lastMouseEvent != null ) {
+						postEvent( lastMouseEvent );
+						lastMouseEvent = null;
+					}
+
+					uninstallEventQueue();
+					return;
+				}
+			} );
+			timeoutTimer.setRepeats( false );
+
+			Toolkit.getDefaultToolkit().getSystemEventQueue().push( this );
+		}
+
+		void uninstall() {
+			mouseUpdateTimer.stop();
+			mouseUpdateTimer = null;
+
+			timeoutTimer.stop();
+			timeoutTimer = null;
+
+			lastMouseEvent = null;
+
+			super.pop();
+		}
+
+		@Override
+		protected void dispatchEvent( AWTEvent e ) {
+			int id = e.getID();
+
+			if( e instanceof MouseEvent &&
+				(id == MouseEvent.MOUSE_MOVED || id == MouseEvent.MOUSE_DRAGGED) )
+			{
+				newMouseX = ((MouseEvent)e).getXOnScreen();
+				newMouseY = ((MouseEvent)e).getYOnScreen();
+
+				if( safeTrianglePainter != null )
+					safeTrianglePainter.repaint();
+
+				mouseUpdateTimer.stop();
+				timeoutTimer.stop();
+
+				// check whether mouse moved within safe triangle
+				if( createSafeTriangle().contains( newMouseX, newMouseY ) ) {
+					// update mouse location delayed (this changes the safe triangle)
+					mouseUpdateTimer.start();
+
+					timeoutTimer.start();
+
+					// remember last mouse event, which will be posted if the mouse stops moving
+					lastMouseEvent = e;
+
+					// ignore mouse event
+					return;
+				}
+
+				// update mouse location immediately (this changes the safe triangle)
+				mouseX = newMouseX;
+				mouseY = newMouseY;
+			}
+
+			super.dispatchEvent( e );
+		}
+	}
+
+	//---- class SafeTrianglePainter ------------------------------------------
+
+	private class SafeTrianglePainter
+		extends JComponent
+	{
+		SafeTrianglePainter( JPopupMenu popup ) {
+			Window window = SwingUtilities.windowForComponent( popup.getInvoker() );
+			if( window instanceof RootPaneContainer ) {
+				JLayeredPane layeredPane = ((RootPaneContainer)window).getLayeredPane();
+				setSize( layeredPane.getSize() );
+				layeredPane.add( this, new Integer( JLayeredPane.POPUP_LAYER + 1 ) );
+			}
+		}
+
+		void uninstall() {
+			Container parent = getParent();
+			if( parent != null ) {
+				parent.remove( this );
+				parent.repaint();
+			}
+		}
+
+		@Override
+		protected void paintComponent( Graphics g ) {
+			Point locationOnScreen = getLocationOnScreen();
+			g.translate( -locationOnScreen.x, -locationOnScreen.y );
+
+			g.setColor( Color.red );
+			((Graphics2D)g).draw( createSafeTriangle() );
+		}
+	}
+}

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

@@ -0,0 +1,622 @@
+/*
+ * Copyright 2022 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.Component;
+import java.awt.event.*;
+import javax.swing.*;
+import net.miginfocom.swing.*;
+
+/**
+ * @author Karl Tauber
+ */
+public class FlatSubMenusTest
+	extends FlatTestPanel
+{
+	public static void main( String[] args ) {
+		SwingUtilities.invokeLater( () -> {
+			FlatTestFrame frame = FlatTestFrame.create( args, "FlatSubMenusTest" );
+			UIManager.put( "FlatLaf.debug.menu.showSafeTriangle", true );
+			frame.applyComponentOrientationToFrame = true;
+			frame.showFrame( FlatSubMenusTest::new, panel -> ((FlatSubMenusTest)panel).menuBar );
+		} );
+	}
+
+	FlatSubMenusTest() {
+		initComponents();
+	}
+
+	private void showPopupMenuButtonActionPerformed(ActionEvent e) {
+		Component invoker = (Component) e.getSource();
+		PopupMenu popupMenu = new PopupMenu();
+		popupMenu.applyComponentOrientation( getComponentOrientation() );
+		popupMenu.show( invoker, 0, invoker.getHeight() );
+	}
+
+	private void initComponents() {
+		// JFormDesigner - Component initialization - DO NOT MODIFY  //GEN-BEGIN:initComponents
+		JButton showPopupMenuButton = new JButton();
+		menuBar = new JMenuBar();
+		JMenu menu3 = new JMenu();
+		JMenuItem menuItem1 = new JMenuItem();
+		JMenuItem menuItem50 = new JMenuItem();
+		JMenu menu4 = new JMenu();
+		JMenuItem menuItem9 = new JMenuItem();
+		JMenuItem menuItem10 = new JMenuItem();
+		JMenuItem menuItem11 = new JMenuItem();
+		JMenu menu8 = new JMenu();
+		JMenu menu21 = new JMenu();
+		JMenuItem menuItem81 = new JMenuItem();
+		JMenuItem menuItem82 = new JMenuItem();
+		JMenuItem menuItem83 = new JMenuItem();
+		JMenuItem menuItem41 = new JMenuItem();
+		JMenuItem menuItem42 = new JMenuItem();
+		JMenuItem menuItem43 = new JMenuItem();
+		JMenuItem menuItem44 = new JMenuItem();
+		JMenuItem menuItem45 = new JMenuItem();
+		JMenuItem menuItem46 = new JMenuItem();
+		JMenuItem menuItem12 = new JMenuItem();
+		JMenuItem menuItem13 = new JMenuItem();
+		JMenuItem menuItem14 = new JMenuItem();
+		JMenuItem menuItem2 = new JMenuItem();
+		JMenu menu5 = new JMenu();
+		JMenuItem menuItem15 = new JMenuItem();
+		JMenuItem menuItem16 = new JMenuItem();
+		JMenuItem menuItem17 = new JMenuItem();
+		JMenuItem menuItem18 = new JMenuItem();
+		JMenuItem menuItem19 = new JMenuItem();
+		JMenuItem menuItem20 = new JMenuItem();
+		JMenuItem menuItem21 = new JMenuItem();
+		JMenuItem menuItem22 = new JMenuItem();
+		JMenuItem menuItem23 = new JMenuItem();
+		JMenuItem menuItem24 = new JMenuItem();
+		JMenuItem menuItem25 = new JMenuItem();
+		JMenuItem menuItem26 = new JMenuItem();
+		JMenuItem menuItem27 = new JMenuItem();
+		JMenuItem menuItem28 = new JMenuItem();
+		JMenuItem menuItem29 = new JMenuItem();
+		JMenu menu6 = new JMenu();
+		JMenuItem menuItem30 = new JMenuItem();
+		JMenuItem menuItem31 = new JMenuItem();
+		JMenuItem menuItem32 = new JMenuItem();
+		JMenu menu9 = new JMenu();
+		JMenuItem menuItem47 = new JMenuItem();
+		JMenuItem menuItem48 = new JMenuItem();
+		JMenuItem menuItem49 = new JMenuItem();
+		JMenuItem menuItem33 = new JMenuItem();
+		JMenuItem menuItem34 = new JMenuItem();
+		JMenuItem menuItem3 = new JMenuItem();
+		JMenuItem menuItem4 = new JMenuItem();
+		JMenuItem menuItem5 = new JMenuItem();
+		JMenuItem menuItem6 = new JMenuItem();
+		JMenuItem menuItem7 = new JMenuItem();
+		JMenuItem menuItem8 = new JMenuItem();
+		JMenu menu7 = new JMenu();
+		JMenuItem menuItem35 = new JMenuItem();
+		JMenuItem menuItem37 = new JMenuItem();
+		JMenuItem menuItem36 = new JMenuItem();
+		JMenuItem menuItem38 = new JMenuItem();
+		JMenuItem menuItem39 = new JMenuItem();
+		JMenuItem menuItem40 = new JMenuItem();
+
+		//======== this ========
+		setLayout(new MigLayout(
+			"ltr,insets dialog,hidemode 3",
+			// columns
+			"[]",
+			// rows
+			"[]"));
+
+		//---- showPopupMenuButton ----
+		showPopupMenuButton.setText("show JPopupMenu");
+		showPopupMenuButton.addActionListener(e -> showPopupMenuButtonActionPerformed(e));
+		add(showPopupMenuButton, "cell 0 0");
+
+		//======== menuBar ========
+		{
+
+			//======== menu3 ========
+			{
+				menu3.setText("main menu");
+
+				//---- menuItem1 ----
+				menuItem1.setText("text");
+				menu3.add(menuItem1);
+
+				//---- menuItem50 ----
+				menuItem50.setText("text");
+				menu3.add(menuItem50);
+
+				//======== menu4 ========
+				{
+					menu4.setText("text");
+
+					//---- menuItem9 ----
+					menuItem9.setText("text");
+					menu4.add(menuItem9);
+
+					//---- menuItem10 ----
+					menuItem10.setText("text text");
+					menu4.add(menuItem10);
+
+					//---- menuItem11 ----
+					menuItem11.setText("text");
+					menu4.add(menuItem11);
+
+					//======== menu8 ========
+					{
+						menu8.setText("text");
+
+						//======== menu21 ========
+						{
+							menu21.setText("text");
+
+							//---- menuItem81 ----
+							menuItem81.setText("text");
+							menu21.add(menuItem81);
+
+							//---- menuItem82 ----
+							menuItem82.setText("text");
+							menu21.add(menuItem82);
+
+							//---- menuItem83 ----
+							menuItem83.setText("text");
+							menu21.add(menuItem83);
+						}
+						menu8.add(menu21);
+
+						//---- menuItem41 ----
+						menuItem41.setText("text");
+						menu8.add(menuItem41);
+
+						//---- menuItem42 ----
+						menuItem42.setText("text");
+						menu8.add(menuItem42);
+
+						//---- menuItem43 ----
+						menuItem43.setText("text");
+						menu8.add(menuItem43);
+
+						//---- menuItem44 ----
+						menuItem44.setText("text");
+						menu8.add(menuItem44);
+
+						//---- menuItem45 ----
+						menuItem45.setText("text");
+						menu8.add(menuItem45);
+
+						//---- menuItem46 ----
+						menuItem46.setText("text");
+						menu8.add(menuItem46);
+					}
+					menu4.add(menu8);
+
+					//---- menuItem12 ----
+					menuItem12.setText("text");
+					menu4.add(menuItem12);
+
+					//---- menuItem13 ----
+					menuItem13.setText("text");
+					menu4.add(menuItem13);
+
+					//---- menuItem14 ----
+					menuItem14.setText("text");
+					menu4.add(menuItem14);
+				}
+				menu3.add(menu4);
+
+				//---- menuItem2 ----
+				menuItem2.setText("text");
+				menu3.add(menuItem2);
+
+				//======== menu5 ========
+				{
+					menu5.setText("text");
+
+					//---- menuItem15 ----
+					menuItem15.setText("text bla bla");
+					menu5.add(menuItem15);
+
+					//---- menuItem16 ----
+					menuItem16.setText("text");
+					menu5.add(menuItem16);
+
+					//---- menuItem17 ----
+					menuItem17.setText("text");
+					menu5.add(menuItem17);
+
+					//---- menuItem18 ----
+					menuItem18.setText("text");
+					menu5.add(menuItem18);
+
+					//---- menuItem19 ----
+					menuItem19.setText("text");
+					menu5.add(menuItem19);
+
+					//---- menuItem20 ----
+					menuItem20.setText("text");
+					menu5.add(menuItem20);
+
+					//---- menuItem21 ----
+					menuItem21.setText("text");
+					menu5.add(menuItem21);
+
+					//---- menuItem22 ----
+					menuItem22.setText("text");
+					menu5.add(menuItem22);
+
+					//---- menuItem23 ----
+					menuItem23.setText("text");
+					menu5.add(menuItem23);
+
+					//---- menuItem24 ----
+					menuItem24.setText("text");
+					menu5.add(menuItem24);
+
+					//---- menuItem25 ----
+					menuItem25.setText("text");
+					menu5.add(menuItem25);
+
+					//---- menuItem26 ----
+					menuItem26.setText("text");
+					menu5.add(menuItem26);
+
+					//---- menuItem27 ----
+					menuItem27.setText("text");
+					menu5.add(menuItem27);
+
+					//---- menuItem28 ----
+					menuItem28.setText("text");
+					menu5.add(menuItem28);
+
+					//---- menuItem29 ----
+					menuItem29.setText("text");
+					menu5.add(menuItem29);
+				}
+				menu3.add(menu5);
+
+				//======== menu6 ========
+				{
+					menu6.setText("text");
+
+					//---- menuItem30 ----
+					menuItem30.setText("text o text");
+					menu6.add(menuItem30);
+
+					//---- menuItem31 ----
+					menuItem31.setText("text");
+					menu6.add(menuItem31);
+
+					//---- menuItem32 ----
+					menuItem32.setText("text");
+					menu6.add(menuItem32);
+
+					//======== menu9 ========
+					{
+						menu9.setText("text");
+
+						//---- menuItem47 ----
+						menuItem47.setText("text");
+						menu9.add(menuItem47);
+
+						//---- menuItem48 ----
+						menuItem48.setText("text");
+						menu9.add(menuItem48);
+
+						//---- menuItem49 ----
+						menuItem49.setText("text");
+						menu9.add(menuItem49);
+					}
+					menu6.add(menu9);
+
+					//---- menuItem33 ----
+					menuItem33.setText("text");
+					menu6.add(menuItem33);
+
+					//---- menuItem34 ----
+					menuItem34.setText("text");
+					menu6.add(menuItem34);
+				}
+				menu3.add(menu6);
+
+				//---- menuItem3 ----
+				menuItem3.setText("text");
+				menu3.add(menuItem3);
+
+				//---- menuItem4 ----
+				menuItem4.setText("longer text");
+				menu3.add(menuItem4);
+
+				//---- menuItem5 ----
+				menuItem5.setText("text");
+				menu3.add(menuItem5);
+
+				//---- menuItem6 ----
+				menuItem6.setText("text");
+				menu3.add(menuItem6);
+
+				//---- menuItem7 ----
+				menuItem7.setText("text");
+				menu3.add(menuItem7);
+
+				//---- menuItem8 ----
+				menuItem8.setText("text");
+				menu3.add(menuItem8);
+
+				//======== menu7 ========
+				{
+					menu7.setText("text");
+
+					//---- menuItem35 ----
+					menuItem35.setText("text abc");
+					menu7.add(menuItem35);
+
+					//---- menuItem37 ----
+					menuItem37.setText("text");
+					menu7.add(menuItem37);
+
+					//---- menuItem36 ----
+					menuItem36.setText("text");
+					menu7.add(menuItem36);
+
+					//---- menuItem38 ----
+					menuItem38.setText("text");
+					menu7.add(menuItem38);
+
+					//---- menuItem39 ----
+					menuItem39.setText("text");
+					menu7.add(menuItem39);
+
+					//---- menuItem40 ----
+					menuItem40.setText("text");
+					menu7.add(menuItem40);
+				}
+				menu3.add(menu7);
+			}
+			menuBar.add(menu3);
+		}
+		// JFormDesigner - End of component initialization  //GEN-END:initComponents
+	}
+
+	// JFormDesigner - Variables declaration - DO NOT MODIFY  //GEN-BEGIN:variables
+	private JMenuBar menuBar;
+	// JFormDesigner - End of variables declaration  //GEN-END:variables
+
+	//---- class PopupMenu ----------------------------------------------------
+
+	private class PopupMenu extends JPopupMenu {
+		private PopupMenu() {
+			initComponents();
+		}
+
+		private void initComponents() {
+			// JFormDesigner - Component initialization - DO NOT MODIFY  //GEN-BEGIN:initComponents
+			JMenuItem menuItem54 = new JMenuItem();
+			JMenuItem menuItem51 = new JMenuItem();
+			JMenu menu10 = new JMenu();
+			JMenuItem menuItem57 = new JMenuItem();
+			JMenuItem menuItem58 = new JMenuItem();
+			JMenu menu14 = new JMenu();
+			JMenu menu18 = new JMenu();
+			JMenu menu19 = new JMenu();
+			JMenuItem menuItem76 = new JMenuItem();
+			JMenuItem menuItem77 = new JMenuItem();
+			JMenuItem menuItem78 = new JMenuItem();
+			JMenu menu20 = new JMenu();
+			JMenuItem menuItem73 = new JMenuItem();
+			JMenuItem menuItem74 = new JMenuItem();
+			JMenuItem menuItem75 = new JMenuItem();
+			JMenuItem menuItem79 = new JMenuItem();
+			JMenuItem menuItem80 = new JMenuItem();
+			JMenuItem menuItem70 = new JMenuItem();
+			JMenuItem menuItem71 = new JMenuItem();
+			JMenuItem menuItem72 = new JMenuItem();
+			JMenuItem menuItem59 = new JMenuItem();
+			JMenuItem menuItem60 = new JMenuItem();
+			JMenuItem menuItem52 = new JMenuItem();
+			JMenu menu11 = new JMenu();
+			JMenuItem menuItem61 = new JMenuItem();
+			JMenuItem menuItem62 = new JMenuItem();
+			JMenuItem menuItem63 = new JMenuItem();
+			JMenu menu12 = new JMenu();
+			JMenuItem menuItem64 = new JMenuItem();
+			JMenuItem menuItem65 = new JMenuItem();
+			JMenuItem menuItem66 = new JMenuItem();
+			JMenuItem menuItem53 = new JMenuItem();
+			JMenuItem menuItem55 = new JMenuItem();
+			JMenuItem menuItem56 = new JMenuItem();
+			JMenu menu13 = new JMenu();
+			JMenuItem menuItem67 = new JMenuItem();
+			JMenuItem menuItem68 = new JMenuItem();
+			JMenuItem menuItem69 = new JMenuItem();
+
+			//======== this ========
+
+			//---- menuItem54 ----
+			menuItem54.setText("text");
+			add(menuItem54);
+
+			//---- menuItem51 ----
+			menuItem51.setText("text text");
+			add(menuItem51);
+
+			//======== menu10 ========
+			{
+				menu10.setText("text");
+
+				//---- menuItem57 ----
+				menuItem57.setText("text");
+				menu10.add(menuItem57);
+
+				//---- menuItem58 ----
+				menuItem58.setText("text");
+				menu10.add(menuItem58);
+
+				//======== menu14 ========
+				{
+					menu14.setText("text");
+
+					//======== menu18 ========
+					{
+						menu18.setText("text");
+
+						//======== menu19 ========
+						{
+							menu19.setText("text");
+
+							//---- menuItem76 ----
+							menuItem76.setText("text");
+							menu19.add(menuItem76);
+
+							//---- menuItem77 ----
+							menuItem77.setText("text");
+							menu19.add(menuItem77);
+
+							//---- menuItem78 ----
+							menuItem78.setText("text");
+							menu19.add(menuItem78);
+						}
+						menu18.add(menu19);
+
+						//======== menu20 ========
+						{
+							menu20.setText("text");
+
+							//---- menuItem73 ----
+							menuItem73.setText("text");
+							menu20.add(menuItem73);
+
+							//---- menuItem74 ----
+							menuItem74.setText("text");
+							menu20.add(menuItem74);
+
+							//---- menuItem75 ----
+							menuItem75.setText("text");
+							menu20.add(menuItem75);
+						}
+						menu18.add(menu20);
+
+						//---- menuItem79 ----
+						menuItem79.setText("text");
+						menu18.add(menuItem79);
+
+						//---- menuItem80 ----
+						menuItem80.setText("text");
+						menu18.add(menuItem80);
+					}
+					menu14.add(menu18);
+
+					//---- menuItem70 ----
+					menuItem70.setText("text");
+					menu14.add(menuItem70);
+
+					//---- menuItem71 ----
+					menuItem71.setText("text");
+					menu14.add(menuItem71);
+
+					//---- menuItem72 ----
+					menuItem72.setText("text");
+					menu14.add(menuItem72);
+				}
+				menu10.add(menu14);
+
+				//---- menuItem59 ----
+				menuItem59.setText("text");
+				menu10.add(menuItem59);
+
+				//---- menuItem60 ----
+				menuItem60.setText("text");
+				menu10.add(menuItem60);
+			}
+			add(menu10);
+
+			//---- menuItem52 ----
+			menuItem52.setText("text");
+			add(menuItem52);
+
+			//======== menu11 ========
+			{
+				menu11.setText("text");
+
+				//---- menuItem61 ----
+				menuItem61.setText("text");
+				menu11.add(menuItem61);
+
+				//---- menuItem62 ----
+				menuItem62.setText("text");
+				menu11.add(menuItem62);
+
+				//---- menuItem63 ----
+				menuItem63.setText("text");
+				menu11.add(menuItem63);
+			}
+			add(menu11);
+
+			//======== menu12 ========
+			{
+				menu12.setText("text");
+
+				//---- menuItem64 ----
+				menuItem64.setText("text");
+				menu12.add(menuItem64);
+
+				//---- menuItem65 ----
+				menuItem65.setText("text");
+				menu12.add(menuItem65);
+
+				//---- menuItem66 ----
+				menuItem66.setText("text");
+				menu12.add(menuItem66);
+			}
+			add(menu12);
+
+			//---- menuItem53 ----
+			menuItem53.setText("text");
+			add(menuItem53);
+
+			//---- menuItem55 ----
+			menuItem55.setText("text");
+			add(menuItem55);
+
+			//---- menuItem56 ----
+			menuItem56.setText("text");
+			add(menuItem56);
+
+			//======== menu13 ========
+			{
+				menu13.setText("text");
+
+				//---- menuItem67 ----
+				menuItem67.setText("text");
+				menu13.add(menuItem67);
+
+				//---- menuItem68 ----
+				menuItem68.setText("text");
+				menu13.add(menuItem68);
+
+				//---- menuItem69 ----
+				menuItem69.setText("text");
+				menu13.add(menuItem69);
+			}
+			add(menu13);
+			// JFormDesigner - End of component initialization  //GEN-END:initComponents
+		}
+
+		// JFormDesigner - Variables declaration - DO NOT MODIFY  //GEN-BEGIN:variables
+		// JFormDesigner - End of variables declaration  //GEN-END:variables
+	}
+}

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

@@ -0,0 +1,439 @@
+JFDML JFormDesigner: "7.0.5.0.404" Java: "17" 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 net.miginfocom.swing.MigLayout ) {
+			"$layoutConstraints": "ltr,insets dialog,hidemode 3"
+			"$columnConstraints": "[]"
+			"$rowConstraints": "[]"
+		} ) {
+			name: "this"
+			add( new FormComponent( "javax.swing.JButton" ) {
+				name: "showPopupMenuButton"
+				"text": "show JPopupMenu"
+				addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "showPopupMenuButtonActionPerformed", true ) )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 0"
+			} )
+		}, new FormLayoutConstraints( null ) {
+			"location": new java.awt.Point( 0, 0 )
+			"size": new java.awt.Dimension( 390, 130 )
+		} )
+		add( new FormContainer( "javax.swing.JMenuBar", new FormLayoutManager( class javax.swing.JMenuBar ) ) {
+			name: "menuBar"
+			auxiliary() {
+				"JavaCodeGenerator.variableLocal": false
+			}
+			add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+				name: "menu3"
+				"text": "main menu"
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem1"
+					"text": "text"
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem50"
+					"text": "text"
+				} )
+				add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+					name: "menu4"
+					"text": "text"
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem9"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem10"
+						"text": "text text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem11"
+						"text": "text"
+					} )
+					add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+						name: "menu8"
+						"text": "text"
+						add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+							name: "menu21"
+							"text": "text"
+							add( new FormComponent( "javax.swing.JMenuItem" ) {
+								name: "menuItem81"
+								"text": "text"
+							} )
+							add( new FormComponent( "javax.swing.JMenuItem" ) {
+								name: "menuItem82"
+								"text": "text"
+							} )
+							add( new FormComponent( "javax.swing.JMenuItem" ) {
+								name: "menuItem83"
+								"text": "text"
+							} )
+						} )
+						add( new FormComponent( "javax.swing.JMenuItem" ) {
+							name: "menuItem41"
+							"text": "text"
+						} )
+						add( new FormComponent( "javax.swing.JMenuItem" ) {
+							name: "menuItem42"
+							"text": "text"
+						} )
+						add( new FormComponent( "javax.swing.JMenuItem" ) {
+							name: "menuItem43"
+							"text": "text"
+						} )
+						add( new FormComponent( "javax.swing.JMenuItem" ) {
+							name: "menuItem44"
+							"text": "text"
+						} )
+						add( new FormComponent( "javax.swing.JMenuItem" ) {
+							name: "menuItem45"
+							"text": "text"
+						} )
+						add( new FormComponent( "javax.swing.JMenuItem" ) {
+							name: "menuItem46"
+							"text": "text"
+						} )
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem12"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem13"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem14"
+						"text": "text"
+					} )
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem2"
+					"text": "text"
+				} )
+				add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+					name: "menu5"
+					"text": "text"
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem15"
+						"text": "text bla bla"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem16"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem17"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem18"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem19"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem20"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem21"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem22"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem23"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem24"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem25"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem26"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem27"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem28"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem29"
+						"text": "text"
+					} )
+				} )
+				add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+					name: "menu6"
+					"text": "text"
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem30"
+						"text": "text o text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem31"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem32"
+						"text": "text"
+					} )
+					add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+						name: "menu9"
+						"text": "text"
+						add( new FormComponent( "javax.swing.JMenuItem" ) {
+							name: "menuItem47"
+							"text": "text"
+						} )
+						add( new FormComponent( "javax.swing.JMenuItem" ) {
+							name: "menuItem48"
+							"text": "text"
+						} )
+						add( new FormComponent( "javax.swing.JMenuItem" ) {
+							name: "menuItem49"
+							"text": "text"
+						} )
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem33"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem34"
+						"text": "text"
+					} )
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem3"
+					"text": "text"
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem4"
+					"text": "longer text"
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem5"
+					"text": "text"
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem6"
+					"text": "text"
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem7"
+					"text": "text"
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem8"
+					"text": "text"
+				} )
+				add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+					name: "menu7"
+					"text": "text"
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem35"
+						"text": "text abc"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem37"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem36"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem38"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem39"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem40"
+						"text": "text"
+					} )
+				} )
+			} )
+		}, new FormLayoutConstraints( null ) {
+			"location": new java.awt.Point( 0, 175 )
+		} )
+		add( new FormContainer( "javax.swing.JPopupMenu", new FormLayoutManager( class javax.swing.JPopupMenu ) ) {
+			name: "popupMenu1"
+			auxiliary() {
+				"JavaCodeGenerator.className": "PopupMenu"
+			}
+			add( new FormComponent( "javax.swing.JMenuItem" ) {
+				name: "menuItem54"
+				"text": "text"
+			} )
+			add( new FormComponent( "javax.swing.JMenuItem" ) {
+				name: "menuItem51"
+				"text": "text text"
+			} )
+			add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+				name: "menu10"
+				"text": "text"
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem57"
+					"text": "text"
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem58"
+					"text": "text"
+				} )
+				add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+					name: "menu14"
+					"text": "text"
+					add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+						name: "menu18"
+						"text": "text"
+						add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+							name: "menu19"
+							"text": "text"
+							add( new FormComponent( "javax.swing.JMenuItem" ) {
+								name: "menuItem76"
+								"text": "text"
+							} )
+							add( new FormComponent( "javax.swing.JMenuItem" ) {
+								name: "menuItem77"
+								"text": "text"
+							} )
+							add( new FormComponent( "javax.swing.JMenuItem" ) {
+								name: "menuItem78"
+								"text": "text"
+							} )
+						} )
+						add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+							name: "menu20"
+							"text": "text"
+							add( new FormComponent( "javax.swing.JMenuItem" ) {
+								name: "menuItem73"
+								"text": "text"
+							} )
+							add( new FormComponent( "javax.swing.JMenuItem" ) {
+								name: "menuItem74"
+								"text": "text"
+							} )
+							add( new FormComponent( "javax.swing.JMenuItem" ) {
+								name: "menuItem75"
+								"text": "text"
+							} )
+						} )
+						add( new FormComponent( "javax.swing.JMenuItem" ) {
+							name: "menuItem79"
+							"text": "text"
+						} )
+						add( new FormComponent( "javax.swing.JMenuItem" ) {
+							name: "menuItem80"
+							"text": "text"
+						} )
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem70"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem71"
+						"text": "text"
+					} )
+					add( new FormComponent( "javax.swing.JMenuItem" ) {
+						name: "menuItem72"
+						"text": "text"
+					} )
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem59"
+					"text": "text"
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem60"
+					"text": "text"
+				} )
+			} )
+			add( new FormComponent( "javax.swing.JMenuItem" ) {
+				name: "menuItem52"
+				"text": "text"
+			} )
+			add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+				name: "menu11"
+				"text": "text"
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem61"
+					"text": "text"
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem62"
+					"text": "text"
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem63"
+					"text": "text"
+				} )
+			} )
+			add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+				name: "menu12"
+				"text": "text"
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem64"
+					"text": "text"
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem65"
+					"text": "text"
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem66"
+					"text": "text"
+				} )
+			} )
+			add( new FormComponent( "javax.swing.JMenuItem" ) {
+				name: "menuItem53"
+				"text": "text"
+			} )
+			add( new FormComponent( "javax.swing.JMenuItem" ) {
+				name: "menuItem55"
+				"text": "text"
+			} )
+			add( new FormComponent( "javax.swing.JMenuItem" ) {
+				name: "menuItem56"
+				"text": "text"
+			} )
+			add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
+				name: "menu13"
+				"text": "text"
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem67"
+					"text": "text"
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem68"
+					"text": "text"
+				} )
+				add( new FormComponent( "javax.swing.JMenuItem" ) {
+					name: "menuItem69"
+					"text": "text"
+				} )
+			} )
+		}, new FormLayoutConstraints( null ) {
+			"location": new java.awt.Point( 275, 175 )
+		} )
+	}
+}