Menus

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Menus

We can also develop an application with a Menu. As a name indicates a Menu consists of Menu objects.

We can also develop an application with a Menu. As a name indicates a Menu consists of Menu objects.

Menus

     

We can also develop an application with a Menu. As a name indicates a Menu consists of Menu objects. These Menu objects comprise of MenuItem objects which can be selected by the user with a click of a mouse. A MenuItem may be a String, checkbox, separator, menu etc.

Following are the steps to to add menus to any Frame:

  1. You need to create a MenuBar first with the help of the following method.

  MenuBar mb = new MenuBar();

   2.    Then you need to create a Menu using Menu m = new Menu("File");.

   3.  Now the MenuItem options can be added to the Menu from top to bottom, using the following methods.

  mi.add(new MenuItem("Open"));
  mi.add(new CheckboxMenuItem("Type here")); 

  4Now you can add the Menu to the MenuBar from left to right using mi.add(m);.

  5.   Finally, you need to add the MenuBar to the Frame by calling the setMenuBar() method.

The program code given below, creates an application window with a menu bar.

 

import java.awt.*; 
import java.awt.event.*; 
 
public class MainWindow extends Frame 
  public MainWindow() { 
  super("Menu Window")
  setSize(400400)
  FileMenu fileMenu = new FileMenu(this)
  HelpMenu helpMenu = new HelpMenu(this)
  MenuBar mb = new MenuBar()
  mb.add(fileMenu)
  mb.add(helpMenu)
  setMenuBar(mb)
  addWindowListener(new WindowAdapter() { 
  public void windowClosing(WindowEvent e) { 
  exit()
  
  })
  
 
  public void exit() { 
  setVisible(false)
  dispose()
  System.exit(0)
  
 
  public static void main(String args[]) { 
  MainWindow w = new MainWindow()
  w.setVisible(true)
  

 
class FileMenu extends Menu implements ActionListener 
  MainWindow mw;  
  public FileMenu(MainWindow m) { 
  super("File")
  mw = m; 
  MenuItem mi; 
  add(mi = new MenuItem("Open"))
  mi.addActionListener(this)
  add(mi = new MenuItem("Close"))
  mi.addActionListener(this)
  add(mi = new MenuItem("Exit"))
  mi.addActionListener(this)
  
 
  public void actionPerformed(ActionEvent e) { 
  String item = e.getActionCommand()
  if (item.equals("Exit"))  
  mw.exit()
  else  
  System.out.println("Selected FileMenu " + item)
  

 
class HelpMenu extends Menu implements ActionListener 
  MainWindow mw;  
  public HelpMenu(MainWindow m) { 
  super("Help")
  mw = m; 
  MenuItem mi; 
  add(mi = new MenuItem("Basics"))
  mi.addActionListener(this)
  add(mi = new MenuItem("Advanced"))
  mi.addActionListener(this)
  addSeparator()
  add(mi = new CheckboxMenuItem("Manual"))
  mi.addActionListener(this)
 
  Menu subMenu = new Menu("Miscellaneous")
  subMenu.add(mi = new MenuItem("Help"))
  mi.addActionListener(this)
  subMenu.add(mi = new MenuItem("Other Option"))
  mi.addActionListener(this)
  add(subMenu)
  
  
  public void actionPerformed(ActionEvent e) { 
  String item = e.getActionCommand()
  if (item.equals("Basics")) 
  System.out.println("Basics")
  else if (item.equals("Help"))  
  System.out.println("Help")
  

Output of the program:

C:\newprgrm>javac MainWindow.java

C:\newprgrm>java MainWindow

Download this example.

 

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