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

public class WindowListenerDemo extends JFrame 
                 implements ActionListener, WindowListener
{
    public static final int WIDTH = 300; 
    public static final int HEIGHT = 200;

    public static void main(String[] args)
    {
        WindowListenerDemo demoWindow = new WindowListenerDemo();
        demoWindow.setVisible(true);
    }

    public WindowListenerDemo()
    {
        setSize(WIDTH, HEIGHT);

        addWindowListener(this);
        setTitle("Window Listener Demonstration");
        Container content = getContentPane();
        content.setBackground(Color.blue);

        content.setLayout(new FlowLayout());

        JButton stopButton = new JButton("Red"); 
        stopButton.addActionListener(this);
        content.add(stopButton); 

        JButton goButton = new JButton("Green");
        goButton.addActionListener(this); 
        content.add(goButton); 
    }

    public void actionPerformed(ActionEvent e) 
    {
       Container content = getContentPane();
       if (e.getActionCommand().equals("Red")) 
           content.setBackground(Color.red);
       else if (e.getActionCommand().equals("Green"))
           content.setBackground(Color.green);
       else
           System.out.println("Error in WindowListenerDemo.");
    }

    public void windowOpened(WindowEvent e)
    {}

    public void windowClosing(WindowEvent e)
    {
        this.dispose();
        System.exit(0);
    }

    public void windowClosed(WindowEvent e)
    {}

    public void windowIconified(WindowEvent e)
    {}

    public void windowDeiconified(WindowEvent e)
    {}

    public void windowActivated(WindowEvent e)
    {}

    public void windowDeactivated(WindowEvent e)
    {}
}