This section provides a tutorial example on how to use the javax.swing.JMenuItem class to create menu items and add them to different menus, sub menus, or the menu bar. Sub menus and menu items added to a menu will be listed vertically when the menu is selected.
Here is an example program I wrote to test the JMenuItem class:
/**
* JMenuItemTest.java
* Copyright (c) 2009 by Dr. Herong Yang, http://www.herongyang.com/
*/
import javax.swing.*;
public class JMenuItemTest {
JFrame myFrame = null;
public static void main(String[] a) {
(new JMenuItemTest()).test();
}
private void test() {
myFrame = new JFrame("Menu Item 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");
myMenuBar.add(myItem);
myFrame.setJMenuBar(myMenuBar);
myFrame.setVisible(true);
}
private JMenu getFileMenu() {
JMenu myMenu = new JMenu("File");
JMenuItem myItem = new JMenuItem("Open");
myMenu.add(myItem);
myItem = new JMenuItem("Close");
myItem.setEnabled(false);
myMenu.add(myItem);
myMenu.addSeparator();
myItem = new JMenuItem("Exit");
myMenu.add(myItem);
return myMenu;
}
private JMenu getColorMenu() {
JMenu myMenu = new JMenu("Color");
JMenuItem myItem = new JMenuItem("Red");
myMenu.add(myItem);
myItem = new JMenuItem("Green");
myMenu.add(myItem);
myItem = new JMenuItem("Blue");
myMenu.add(myItem);
return myMenu;
}
private JMenu getOptionMenu() {
JMenu myMenu = new JMenu("Option");
JMenu mySubMenu = getOnOffMenu("Sound");
myMenu.add(mySubMenu);
mySubMenu = getOnOffMenu("Auto save");
mySubMenu.setEnabled(false);
myMenu.add(mySubMenu);
return myMenu;
}
private JMenu getOnOffMenu(String title) {
JMenu myMenu = new JMenu(title);
JMenuItem myItem = new JMenuItem("On");
myMenu.add(myItem);
myItem = new JMenuItem("Off");
myMenu.add(myItem);
return myMenu;
}
}
If you run this example, you will see the frame window shows up with the menu bar like this:
Interesting notes about this tutorial example:
A menu item can be added directly on the menu bar. The "Help" menu item is added to the menu bar in this example.
But it is strongly not recommended. You will get a crash if you use the arrow key to navigate in the menu bar.
A menu item can be disabled by calling the set setEnabled(false) function.
A disabled menu item will be listed in gray and not be clickable.
The "Close" menu item is disabled in this example.
A menu can also be disabled by calling the set setEnabled(false) function.
A disabled menu will be listed in gray and not be clickable.
The "Auto save" menu item is disabled in this example.
Sample programs listed in this section have been tested with JDK 1.6.0.
