javax.swing.event.MenuKeyListener - Menu Key Listener Interface

This section provides a tutorial example on how to use javax.swing.event.MenuKeyListener, menu key listener interface, to catch events fired by JMenuItem objects when a key is typed on the keyboard.

JMenuItem objects also fire events when users interact with them by typing a key on the keyboard. If you want to perform a task when an event occurs on a JMenuItem object, you need to add an event listener to that JMenuItem object. To do this, you need know these Swing classes, interfaces and methods:

javax.swing.event.MenuKeyListener - A Swing interface that allows you to implement your own menu item event handler methods:

javax.swing.event.MenuKeyEvent - A Swing class that represents an event occurred on a menu item. The most important method in this class is:

Here is an example program I wrote to test the MenuKeyListener interface:

/* MenuKeyListenerTest.java
 * Copyright (c) 2014, HerongYang.com, All Rights Reserved.
 */
import javax.swing.*;
import javax.swing.event.*;
public class MenuKeyListenerTest implements MenuKeyListener {
   JFrame myFrame = null;
   public static void main(String[] a) {
      (new MenuKeyListenerTest()).test();
   }
   private void test() {
      myFrame = new JFrame("Menu Listener Test");
      myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      myFrame.setBounds(50,50,250,150);
      myFrame.setContentPane(new JDesktopPane());

      JMenuBar myMenuBar = new JMenuBar();
      JMenu myMenu = getFileMenu();
      myMenuBar.add(myMenu);
      myMenu = getColorMenu();
      myMenuBar.add(myMenu);
      myMenu = getOptionMenu();
      myMenuBar.add(myMenu);

      JMenuItem myItem = new JMenuItem("Help");
      myItem.addMenuKeyListener(this);
      myMenuBar.add(myItem);

      myFrame.setJMenuBar(myMenuBar);
      myFrame.setVisible(true);
   }
   private JMenu getFileMenu() {
      JMenu myMenu = new JMenu("File");
      JMenuItem myItem = new JMenuItem("Open");
      myItem.addMenuKeyListener(this);
      myMenu.add(myItem);
      myItem = new JMenuItem("Close");
      myItem.addMenuKeyListener(this);
      myMenu.add(myItem);
      myMenu.addSeparator();
      myItem.addMenuKeyListener(this);
      myItem = new JMenuItem("Exit");
      myMenu.add(myItem);
      return myMenu;
   }
   private JMenu getColorMenu() {
      JMenu myMenu = new JMenu("Color");
      ButtonGroup myGroup = new ButtonGroup();
      JRadioButtonMenuItem myItem = new JRadioButtonMenuItem("Red");
      myItem.setSelected(true);
      myItem.addMenuKeyListener(this);
      myGroup.add(myItem);
      myMenu.add(myItem);
      myItem = new JRadioButtonMenuItem("Green");
      myItem.addMenuKeyListener(this);
      myGroup.add(myItem);
      myMenu.add(myItem);
      myItem = new JRadioButtonMenuItem("Blue");
      myItem.addMenuKeyListener(this);
      myGroup.add(myItem);
      myMenu.add(myItem);
      return myMenu;
   }
   private JMenu getOptionMenu() {
      JMenu myMenu = new JMenu("Option");
      JMenuItem myItem = new JMenuItem("Sound");
      myItem.addMenuKeyListener(this);
      myMenu.add(myItem);
      myItem = new JMenuItem("Auto save");
      myItem.addMenuKeyListener(this);
      myMenu.add(myItem);
      return myMenu;
   }
   public void menuKeyTyped(MenuKeyEvent e) {
      MenuElement[] path = e.getPath();
      JMenuItem item = (JMenuItem) path[path.length-1];
      System.out.println("Key typed: "+e.getKeyChar()
         + ", "+e.getKeyText(e.getKeyCode())
         + " on "+item.getText());
   }
   public void menuKeyPressed(MenuKeyEvent e) {
      MenuElement[] path = e.getPath();
      JMenuItem item = (JMenuItem) path[path.length-1];
      System.out.println("Key pressed: "+e.getKeyChar()
         + ", "+e.getKeyText(e.getKeyCode())
         + " on "+item.getText());
   }
   public void menuKeyReleased(MenuKeyEvent e) {
      MenuElement[] path = e.getPath();
      JMenuItem item = (JMenuItem) path[path.length-1];
      System.out.println("Key released: "+e.getKeyChar()
         + ", "+e.getKeyText(e.getKeyCode())
         + " on "+item.getText());
   }
}

If you run this example, you will see the frame window shows up with the menu bar like this:
Menu Key Listener Test

If you click the "Color" menu leaving it open, then type the "b" key and the "Shift" key on the keyboard, you will see some messages printed on the Java console window:

Key pressed: b, B on Red
Key pressed: b, B on Green
Key pressed: b, B on Blue
Key pressed: b, B on Help
Key typed: b, Unknown keyCode: 0x0 on Red
Key typed: b, Unknown keyCode: 0x0 on Green
Key typed: b, Unknown keyCode: 0x0 on Blue
Key typed: b, Unknown keyCode: 0x0 on Help
Key released: b, B on Red
Key released: b, B on Green
Key released: b, B on Blue
Key released: b, B on Help
Key pressed: ?, Shift on Red
Key pressed: ?, Shift on Green
Key pressed: ?, Shift on Blue
Key pressed: ?, Shift on Help
Key released: ?, Shift on Red
Key released: ?, Shift on Green
Key released: ?, Shift on Blue
Key released: ?, Shift on Help

Interesting notes about this tutorial example:

Sample programs listed in this section have been tested with JDK 1.6.0 to 1.8.0.

Last update: 2014.

Table of Contents

 About This Book

 Introduction of Java Swing Package

 Graphics Environment of the Local System

 JFrame - Main Frame Class

 JLabel - Swing Label Class

 JButton - Swing Button Class

 JRadioButton - Swing Radio Button Class

 JTextField - Swing Text Field Class

Menu Bar, Menus, Menu Items and Listeners

 JMenuBar, JMenu, and JMenuItem Classes

 JMenuBarTest.java - Menu Bar Test Program

 JMenuTest.java - Menu Test Program

 JMenuItemTest.java - Menu Item Test Program

 JRadioButtonMenuItemTest.java - Radio Button Menu Item Test Program

 JCheckBoxMenuItemTest.java - Check Box Menu Item Test Program

 javax.swing.event.MenuListener - Menu Listener Interface

 MenuItemActionListenerTest.java - Menu Item Action Listener Test

 Item Listener on Radio Button Menu Items

 Item Listener on Check Box Menu Items

javax.swing.event.MenuKeyListener - Menu Key Listener Interface

 setMnemonic() - Setting Keyboard Mnemonics on Menu Items

 setAccelerator() - Setting Keyboard Accelerators on Menu Items

 setMnemonic() - Setting Keyboard Mnemonics on Menus

 Creating Internal Frames inside the Main Frame

 Layout of Components in a Container

 LookAndFeel and UIManager

 Option Dialog Boxes

 JEditorPane - The Editor Pane Class

 SwingWorker - The Background Task Worker

 References

 PDF Printing Version