MenuDemo1.java Source code

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Here is the source code for MenuDemo1.java

Source

/*
 * This example is from the book "Java Foundation Classes in a Nutshell".
 * Written by David Flanagan. Copyright (c) 1999 by O'Reilly & Associates.  
 * You may distribute this source code for non-commercial purposes only.
 * You may study, modify, and use this example for any purpose, as long as
 * this notice is retained.  Note that this example is provided "as is",
 * WITHOUT WARRANTY of any kind either expressed or implied.
 */

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

public class MenuDemo1 {
    public static void main(String[] args) {
        // Create a window for this demo
        JFrame frame = new JFrame("Menu Demo");
        JPanel panel = new JPanel();
        frame.getContentPane().add(panel, "Center");

        // Create an action listener for the menu items we will create
        // The MenuItemActionListener class is defined below
        ActionListener listener = new MenuItemActionListener(panel);

        // Create some menu panes, and fill them with menu items
        // The menuItem() method is important.  It is defined below.
        JMenu file = new JMenu("File");
        file.setMnemonic('F');
        file.add(menuItem("New", listener, "new", 'N', KeyEvent.VK_N));
        file.add(menuItem("Open...", listener, "open", 'O', KeyEvent.VK_O));
        file.add(menuItem("Save", listener, "save", 'S', KeyEvent.VK_S));
        file.add(menuItem("Save As...", listener, "saveas", 'A', KeyEvent.VK_A));

        JMenu edit = new JMenu("Edit");
        edit.setMnemonic('E');
        edit.add(menuItem("Cut", listener, "cut", 0, KeyEvent.VK_X));
        edit.add(menuItem("Copy", listener, "copy", 'C', KeyEvent.VK_C));
        edit.add(menuItem("Paste", listener, "paste", 0, KeyEvent.VK_V));

        // Create a menubar and add these panes to it.
        JMenuBar menubar = new JMenuBar();
        menubar.add(file);
        menubar.add(edit);

        // Add menubar to the main window.  Note special method to add menubars
        frame.setJMenuBar(menubar);

        // Now create a popup menu and add the some stuff to it
        final JPopupMenu popup = new JPopupMenu();
        popup.add(menuItem("Open...", listener, "open", 0, 0));
        popup.addSeparator(); // Add a separator between items
        JMenu colors = new JMenu("Colors"); // Create a submenu
        popup.add(colors); // and add it to the popup menu
        // Now fill the submenu with mutually-exclusive radio buttons
        ButtonGroup colorgroup = new ButtonGroup();
        colors.add(radioItem("Red", listener, "color(red)", colorgroup));
        colors.add(radioItem("Green", listener, "color(green)", colorgroup));
        colors.add(radioItem("Blue", listener, "color(blue)", colorgroup));

        // Arrange to display the popup menu when the user clicks in the window
        panel.addMouseListener(new MouseAdapter() {
            public void mousePressed(MouseEvent e) {
                // Check whether this is the right type of event to pop up a popup
                // menu on this platform.  Usually checks for right button down.
                if (e.isPopupTrigger())
                    popup.show((Component) e.getSource(), e.getX(), e.getY());
            }
        });

        // Finally, make our main window appear
        frame.setSize(450, 300);
        frame.setVisible(true);
    }

    // A convenience method for creating menu items.
    public static JMenuItem menuItem(String label, ActionListener listener, String command, int mnemonic,
            int acceleratorKey) {
        JMenuItem item = new JMenuItem(label);
        item.addActionListener(listener);
        item.setActionCommand(command);
        if (mnemonic != 0)
            item.setMnemonic((char) mnemonic);
        if (acceleratorKey != 0)
            item.setAccelerator(KeyStroke.getKeyStroke(acceleratorKey, java.awt.Event.CTRL_MASK));
        return item;
    }

    // A convenience method for creating radio button menu items.
    public static JMenuItem radioItem(String label, ActionListener listener, String command,
            ButtonGroup mutExGroup) {
        JMenuItem item = new JRadioButtonMenuItem(label);
        item.addActionListener(listener);
        item.setActionCommand(command);
        mutExGroup.add(item);
        return item;
    }

    // A event listener class used with the menu items created above.
    // For this demo, it just displays a dialog box when an item is selected.
    public static class MenuItemActionListener implements ActionListener {
        Component parent;

        public MenuItemActionListener(Component parent) {
            this.parent = parent;
        }

        public void actionPerformed(ActionEvent e) {
            JMenuItem item = (JMenuItem) e.getSource();
            String cmd = item.getActionCommand();
            JOptionPane.showMessageDialog(parent, cmd + " was selected.");
        }
    }
}