SWING - JMenuBar Class
Introduction
The JMenuBar class provides an implementation of a menu bar.
Class declaration
Following is the declaration for javax.swing.JMenuBar class:
public class JMenuBar
extends JComponent
implements Accessible, MenuElement
Class constructors
| S.N. | Constructor & Description |
|---|---|
| 1 | JMenuBar() Creates a new menu bar. |
Class methods
| S.N. | Method & Description |
|---|---|
| 1 | JMenu add(JMenu c) Appends the specified menu to the end of the menu bar. |
| 2 | void addNotify() Overrides JComponent.addNotify to register this menu bar with the current keyboard manager. |
| 3 | AccessibleContext getAccessibleContext() Gets the AccessibleContext associated with this JMenuBar. |
| 4 | Component getComponent() Implemented to be a MenuElement. |
| 5 | Component getComponentAtIndex(int i) Deprecated. replaced by getComponent(int i) |
| 6 | int getComponentIndex(Component c) Returns the index of the specified component. |
| 7 | JMenu getHelpMenu() Gets the help menu for the menu bar. |
| 8 | Insets getMargin() Returns the margin between the menubar's border and its menus. |
| 9 | JMenu getMenu(int index) Returns the menu at the specified position in the menu bar. |
| 10 | int getMenuCount() Returns the number of items in the menu bar. |
| 11 | SingleSelectionModel getSelectionModel() Returns the model object that handles single selections. |
| 12 | MenuElement[] getSubElements() Implemented to be a MenuElement -- returns the menus in this menu bar. |
| 13 | MenuBarUI getUI() Returns the menubar's current UI. |
| 14 | String getUIClassID() Returns the name of the L&F class that renders this component. |
| 16 | boolean isBorderPainted() Returns true if the menu bars border should be painted. |
| 17 | boolean isSelected() Returns true if the menu bar currently has a component selected. |
| 18 | void menuSelectionChanged(boolean isIncluded) Implemented to be a MenuElement -- does nothing. |
| 19 | protected void paintBorder(Graphics g) Paints the menubar's border if BorderPainted property is true. |
| 20 | protected String paramString() Returns a string representation of this JMenuBar. |
| 21 | protected boolean processKeyBinding(KeyStroke ks, KeyEvent e, int condition, boolean pressed) Subclassed to check all the child menus. |
| 22 | void processKeyEvent(KeyEvent e, MenuElement[] path, MenuSelectionManager manager) Implemented to be a MenuElement -- does nothing. |
| 23 | void processMouseEvent(MouseEvent event, MenuElement[] path, MenuSelectionManager manager) Implemented to be a MenuElement -- does nothing. |
| 22 | void removeNotify() Overrides JComponent.removeNotify to unregister this menu bar with the current keyboard manager. |
| 23 | void setBorderPainted(boolean b) Sets whether the border should be painted. |
| 24 | void setHelpMenu(JMenu menu) Sets the help menu that appears when the user selects the "help" option in the menu bar. |
| 25 | void setMargin(Insets m) Sets the margin between the menubar's border and its menus. |
| 26 | void setSelected(Component sel) Sets the currently selected component, producing a a change to the selection model. |
| 27 | void setSelectionModel(SingleSelectionModel model) Sets the model object to handle single selections. |
| 28 | void setUI(MenuBarUI ui) Sets the L&F object that renders this component. |
| 29 | void updateUI() Resets the UI property with a value from the current look and feel. |
Methods inherited
This class inherits methods from the following classes:
javax.swing.JComponent
java.awt.Container
java.awt.Component
java.lang.Object
JMenuBar Example
Create the following java program using any editor of your choice in say D:/ > SWING > com > tutorialspoint > gui >
SwingMenuDemo.java
package com.tutorialspoint.gui;
import java.awt.*;
import java.awt.event.*;
public class SwingMenuDemo {
private JFrame mainFrame;
private JLabel headerLabel;
private JLabel statusLabel;
private JPanel controlPanel;
public SwingMenuDemo(){
prepareGUI();
}
public static void main(String[] args){
SwingMenuDemo swingMenuDemo = new SwingMenuDemo();
swingMenuDemo.showMenuDemo();
}
private void prepareGUI(){
mainFrame = new JFrame("Java SWING Examples");
mainFrame.setSize(400,400);
mainFrame.setLayout(new GridLayout(3, 1));
headerLabel = new JLabel("",JLabel.CENTER );
statusLabel = new JLabel("",JLabel.CENTER);
statusLabel.setSize(350,100);
mainFrame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent windowEvent){
System.exit(0);
}
});
controlPanel = new JPanel();
controlPanel.setLayout(new FlowLayout());
mainFrame.add(headerLabel);
mainFrame.add(controlPanel);
mainFrame.add(statusLabel);
mainFrame.setVisible(true);
}
private void showMenuDemo(){
//create a menu bar
final JMenuBar menuBar = new JMenuBar();
//create menus
JMenu fileMenu = new JMenu("File");
JMenu editMenu = new JMenu("Edit");
final JMenu aboutMenu = new JMenu("About");
final JMenu linkMenu = new JMenu("Links");
//create menu items
JMenuItem newMenuItem = new JMenuItem("New");
newMenuItem.setMnemonic(KeyEvent.VK_N);
newMenuItem.setActionCommand("New");
JMenuItem openMenuItem = new JMenuItem("Open");
openMenuItem.setActionCommand("Open");
JMenuItem saveMenuItem = new JMenuItem("Save");
saveMenuItem.setActionCommand("Save");
JMenuItem exitMenuItem = new JMenuItem("Exit");
exitMenuItem.setActionCommand("Exit");
JMenuItem cutMenuItem = new JMenuItem("Cut");
cutMenuItem.setActionCommand("Cut");
JMenuItem copyMenuItem = new JMenuItem("Copy");
copyMenuItem.setActionCommand("Copy");
JMenuItem pasteMenuItem = new JMenuItem("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 JCheckBoxMenuItem showWindowMenu = new JCheckBoxMenuItem("Show About", true);
showWindowMenu.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent e) {
if(showWindowMenu.getState()){
menuBar.add(aboutMenu);
}else{
menuBar.remove(aboutMenu);
}
}
});
final JRadioButtonMenuItem showLinksMenu =
new JRadioButtonMenuItem("Show Links", true);
showLinksMenu.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent e) {
if(menuBar.getMenu(3)!= null){
menuBar.remove(linkMenu);
mainFrame.repaint();
}else{
menuBar.add(linkMenu);
mainFrame.repaint();
}
}
});
//add menu items to menus
fileMenu.add(newMenuItem);
fileMenu.add(openMenuItem);
fileMenu.add(saveMenuItem);
fileMenu.addSeparator();
fileMenu.add(showWindowMenu);
fileMenu.addSeparator();
fileMenu.add(showLinksMenu);
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);
menuBar.add(linkMenu);
//add menubar to the frame
mainFrame.setJMenuBar(menuBar);
mainFrame.setVisible(true);
}
class MenuItemListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
statusLabel.setText(e.getActionCommand()
+ " JMenuItem clicked.");
}
}
}
Compile the program using command prompt. Go to D:/ > SWING and type the following command.
D:\SWING>javac com\tutorialspoint\gui\SwingMenuDemo.java
If no error comes that means compilation is successful. Run the program using following command.
D:\SWING>java com.tutorialspoint.gui.SwingMenuDemo
Verify the following output
