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AWT CheckboxMenuItem Class
Introduction
The CheckboxMenuItem class represents a check box which can be included in a menu. Selecting the check box in the menu changes control's state from on to off or from off to on.
Class declaration
Following is the declaration for java.awt.CheckboxMenuItem class:
public class CheckboxMenuItem
extends MenuItem
implements ItemSelectable, Accessible
Class constructors
| S.N. | Constructor & Description |
|---|---|
| 1 |
CheckboxMenuItem() Create a check box menu item with an empty label. |
| 2 |
CheckboxMenuItem(label) Create a check box menu item with the specified label. |
| 3 |
CheckboxMenuItem(label, boolean state) Create a check box menu item with the specified label and state. |
Class methods
| S.N. | Method & Description |
|---|---|
| 1 |
void addItemListener(ItemListener l) Adds the specified item listener to receive item events from this check box menu item. |
| 2 |
void addNotify() Creates the peer of the checkbox item. |
| 3 |
AccessibleContext getAccessibleContext() Gets the AccessibleContext associated with this CheckboxMenuItem. |
| 4 |
ItemListener[] getItemListeners() Returns an array of all the item listeners registered on this checkbox menuitem. |
| 5 |
<T extends EventListener> T[] getListeners(Class<T> listenerType) Returns an array of all the objects currently registered as FooListeners upon this CheckboxMenuItem. |
| 6 |
Object[] getSelectedObjects() Returns the an array (length 1) containing the checkbox menu item label or null if the checkbox is not selected. |
| 7 |
boolean getState() Determines whether the state of this check box menu item is "on" or "off." |
| 8 |
param() Returns a representing the state of this CheckBoxMenuItem. |
| 9 |
protected void processEvent(AWTEvent e) Processes events on this check box menu item. |
| 10 |
protected void processItemEvent(ItemEvent e) Processes item events occurring on this check box menu item by dispatching them to any registered ItemListener objects. |
| 11 |
void removeItemListener(ItemListener l) Removes the specified item listener so that it no longer receives item events from this check box menu item. |
| 12 |
void setState(boolean b) Sets this check box menu item to the specifed state. |
Methods inherited
This class inherits methods from the following classes:
java.awt.MenuItem
java.awt.MenuComponent
java.lang.Object
CheckboxMenuItem Example
Create the following java program using any editor of your choice in say D:/ > AWT > com > tutorialspoint > gui >
AWTMenuDemo.java
package com.tutorialspoint.gui;
import java.awt.*;
import java.awt.event.*;
public class AWTMenuDemo {
private Frame mainFrame;
private Label headerLabel;
private Label statusLabel;
private Panel controlPanel;
public AWTMenuDemo(){
prepareGUI();
}
public static void main([] args){
AWTMenuDemo awtMenuDemo = new AWTMenuDemo();
awtMenuDemo.showMenuDemo();
}
private void prepareGUI(){
mainFrame = new Frame("Java AWT Examples");
mainFrame.setSize(400,400);
mainFrame.setLayout(new GridLayout(3, 1));
mainFrame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent windowEvent){
System.exit(0);
}
});
headerLabel = new Label();
headerLabel.setAlignment(Label.CENTER);
statusLabel = new Label();
statusLabel.setAlignment(Label.CENTER);
statusLabel.setSize(350,100);
controlPanel = new Panel();
controlPanel.setLayout(new FlowLayout());
mainFrame.add(headerLabel);
mainFrame.add(controlPanel);
mainFrame.add(statusLabel);
mainFrame.setVisible(true);
}
private void showMenuDemo(){
//create a menu bar
final MenuBar menuBar = new MenuBar();
//create menus
Menu fileMenu = new Menu("File");
Menu editMenu = new Menu("Edit");
final Menu aboutMenu = new Menu("About");
//create menu items
MenuItem newMenuItem =
new MenuItem("New",new MenuShortcut(KeyEvent.VK_N));
newMenuItem.setActionCommand("New");
MenuItem openMenuItem = new MenuItem("Open");
openMenuItem.setActionCommand("Open");
MenuItem saveMenuItem = new MenuItem("Save");
saveMenuItem.setActionCommand("Save");
MenuItem exitMenuItem = new MenuItem("Exit");
exitMenuItem.setActionCommand("Exit");
MenuItem cutMenuItem = new MenuItem("Cut");
cutMenuItem.setActionCommand("Cut");
MenuItem copyMenuItem = new MenuItem("Copy");
copyMenuItem.setActionCommand("Copy");
MenuItem pasteMenuItem = new MenuItem("Paste");
pasteMenuItem.setActionCommand("Paste");
MenuItemListener menuItemListener = new MenuItemListener();
newMenuItem.addActionListener(menuItemListener);
openMenuItem.addActionListener(menuItemListener);
saveMenuItem.addActionListener(menuItemListener);
exitMenuItem.addActionListener(menuItemListener);
cutMenuItem.addActionListener(menuItemListener);
copyMenuItem.addActionListener(menuItemListener);
pasteMenuItem.addActionListener(menuItemListener);
final CheckboxMenuItem showWindowMenu =
new CheckboxMenuItem("Show About", true);
showWindowMenu.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent e) {
if(showWindowMenu.getState()){
menuBar.add(aboutMenu);
}else{
menuBar.remove(aboutMenu);
}
}
});
//add menu items to menus
fileMenu.add(newMenuItem);
fileMenu.add(openMenuItem);
fileMenu.add(saveMenuItem);
fileMenu.addSeparator();
fileMenu.add(showWindowMenu);
fileMenu.addSeparator();
fileMenu.add(exitMenuItem);
editMenu.add(cutMenuItem);
editMenu.add(copyMenuItem);
editMenu.add(pasteMenuItem);
//add menu to menubar
menuBar.add(fileMenu);
menuBar.add(editMenu);
menuBar.add(aboutMenu);
//add menubar to the frame
mainFrame.setMenuBar(menuBar);
mainFrame.setVisible(true);
}
class MenuItemListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
statusLabel.setText(e.getActionCommand()
+ " MenuItem clicked.");
}
}
}
Compile the program using command prompt. Go to D:/ > AWT and type the following command.
D:\AWT>javac com\tutorialspoint\gui\AWTMenuDemo.java
If no error comes that means compilation is successful. Run the program using following command.
D:\AWT>java com.tutorialspoint.gui.AWTMenuDemo
Verify the following output. (Click on File Menu. Unselect "Show About" menu item.)