Java AWT and Popup Menu (PopupMenu) - Example

CreatePopupMenu popMenu = new CreatePopupMenu(this);

package com.java.myapp;

import java.awt.Button;
import java.awt.EventQueue;
import java.awt.Frame;
import java.awt.MenuItem;
import java.awt.PopupMenu;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.WindowEvent;
import javax.swing.JOptionPane;

public class MyForm extends Frame {

	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				MyForm form = new MyForm();
				form.setVisible(true);
			}
		});
	}

	public MyForm() {
		// Create Form Frame
		super("ThaiCreate.Com Java GUI Tutorial");
		setSize(434, 285);
		setLocation(500, 280);
		setLayout(null);

		// Button
		final Button btn = new Button("Pop-up Menu");
		btn.setBounds(140, 120, 150, 20);
		final CreatePopupMenu popMenu = new CreatePopupMenu(this);
		add(popMenu);
		btn.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				popMenu.show(btn, 20, 20);
			}
		});	
		add(btn);
		
		// Mouse Event
		addMouseListener(new MouseAdapter() {
			public void mousePressed(MouseEvent e) {
				if (e.isPopupTrigger())
					popMenu.show(e.getComponent(), e.getX(), e.getY());
			}

			public void mouseReleased(MouseEvent e) {
				if (e.isPopupTrigger())
					popMenu.show(e.getComponent(), e.getX(), e.getY());
			}
		});

		// Close
		addWindowListener(new java.awt.event.WindowAdapter() {
			public void windowClosing(WindowEvent evt) {
				System.exit(0);
			}
		});
	}

	class CreatePopupMenu extends PopupMenu implements ActionListener {
		MyForm ref;

		public CreatePopupMenu(MyForm ref) {
			super("File");
			this.ref = ref;
			MenuItem mnItem;
			add(mnItem = new MenuItem("Menu Item 1"));
			mnItem.addActionListener(this);
			add(mnItem = new MenuItem("Menu Item 2"));
			mnItem.addActionListener(this);
			add(mnItem = new MenuItem("Menu Item 3"));
			mnItem.addActionListener(this);
			add(mnItem = new MenuItem("Menu Item 4"));
			mnItem.addActionListener(this);
			add(mnItem = new MenuItem("Menu Item 5"));
			mnItem.addActionListener(this);
		}

		@Override
		public void actionPerformed(ActionEvent e) {
			// TODO Auto-generated method stub
			String item = e.getActionCommand(); 
			JOptionPane.showMessageDialog(null,
        			"Your Selected : " + item.toString());
		}

	}
}