Copyright Derek O'Reilly, Dundalk Institute of Technology (DkIT), Dundalk, Co. Louth, Ireland.

Menu Components

A menu is a pull-down component of a menuBar. A menuBar can be attached to a component using the setMenuBar() method.

A menu can hold any combination of:

Menu example: (Run Applet)

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MenuDemo extends JApplet
{
    @Override
    public void init()
    {
        this.setContentPane(new View());
    }

    public class View extends JPanel implements ActionListener
    {
        private JLabel message = new JLabel("hello");

        public View()
        {
            super();

            final JMenuBar menuBar = new JMenuBar();
            final JMenu mainMenu = new JMenu("Main Menu");
            final JMenu subMenu = new JMenu("Sub Menu");
            final JMenuItem one = new JMenuItem("one");
            final JMenuItem two = new JMenuItem("two");
            final JMenuItem three = new JMenuItem("three");
            final JMenuItem subItem1 = new JMenuItem("subItem1");
            final JMenuItem subItem2 = new JMenuItem("subItem2");
            final JCheckBoxMenuItem checked = new JCheckBoxMenuItem("checked");

            this.setLayout(new BorderLayout());
            this.add("South", this.message);

            // add the items to the menu
            mainMenu.add(one);
            mainMenu.add(two);
            mainMenu.add(three);
            mainMenu.add(subMenu);
            mainMenu.add(checked);

            // add the items to the sub-menu
            subMenu.add(subItem1);
            subMenu.add(subItem2);

            // attach the menu bar to the applet
            setJMenuBar(menuBar);

            // add the menu to the menu bar
            menuBar.add(mainMenu);

            // add action listeners for the menu items
            one.addActionListener(this);
            two.addActionListener(this);
            three.addActionListener(this);
            checked.addActionListener(this);
            subItem1.addActionListener(this);
            subItem2.addActionListener(this);
        }

        @Override
        public void actionPerformed(ActionEvent e)
        {
            this.message.setText("Item '" + e.getActionCommand() + "' was selected.");
        }
    }
}

PopupMenu

Popup Menu Example: (Run Applet)

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.BevelBorder;

public class PopupMenuDemo extends JApplet
{
    @Override
    public void init()
    {
        this.setContentPane(new View());
    }

    public class View extends JPanel implements ActionListener, MouseListener
    {
        private final JLabel message = new JLabel("");
        private final JPopupMenu mainMenu = new JPopupMenu();

        public View()
        {
            super();

            final JMenu subMenu = new JMenu("Sub Menu");
            final JMenuItem one = new JMenuItem("one");
            final JMenuItem two = new JMenuItem("two");
            final JMenuItem three = new JMenuItem("three");
            final JMenuItem subItem1 = new JMenuItem("subItem1");
            final JMenuItem subItem2 = new JMenuItem("subItem2");

            final JCheckBoxMenuItem checked = new JCheckBoxMenuItem("checked");

            this.setLayout(new BorderLayout());
            this.add("South", this.message);

            // add the items to the menu
            this.mainMenu.add(one);
            this.mainMenu.add(two);
            this.mainMenu.add(three);
            this.mainMenu.add(subMenu);
            this.mainMenu.add(checked);

            // add the items to the sub-menu
            subMenu.add(subItem1);
            subMenu.add(subItem2);

            // set the look-and-feel of the popup menu
            this.mainMenu.setBorder(new BevelBorder(BevelBorder.RAISED));

            // add mouse listener to applet so that popup can be called
            this.addMouseListener(this);

            // add action listeners for the menu items
            one.addActionListener(this);
            two.addActionListener(this);
            three.addActionListener(this);
            checked.addActionListener(this);
            subMenu.addActionListener(this);
            subItem1.addActionListener(this);
            subItem2.addActionListener(this);
        }

        @Override
        public void mouseClicked(MouseEvent e)
        {
            this.mainMenu.show(this.getRootPane(), e.getX(), e.getY());
        }

        // need to override all interface methods
        @Override
        public void mousePressed(MouseEvent e)
        {
        }

        @Override
        public void mouseExited(MouseEvent e)
        {
        }

        @Override
        public void mouseEntered(MouseEvent e)
        {
        }

        @Override
        public void mouseReleased(MouseEvent e)
        {
        }

        @Override
        public void actionPerformed(ActionEvent e)
        {
            this.message.setText("Item '" + e.getActionCommand() + "' was selected.");
        }
    }
}

Copyright Derek O' Reilly, Dundalk Institute of Technology (DkIT), Dundalk, Co. Louth, Ireland.