import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
public class ButtonTest
{
    public static void main(String[] args)
    {
        EventQueue.invokeLater(new Runnable()
        {
            public void run()
            {
                ButtonFrame frame = new ButtonFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            }
        });
    }
}
 
class ButtonFrame extends JFrame
{
    public ButtonFrame()
    {
        setTitle("ButtonTest");
        setSize(DEFAULT_WIDTH,DEFAULT_HEIGHT);
 
        JButton yellowButton = new JButton("Yellow");
        JButton blueButton = new JButton("Blue");
        JButton redButton = new JButton("Red");
 
        buttonPanel = new JPanel();
        buttonPanel.add(yellowButton);
        buttonPanel.add(blueButton);
        buttonPanel.add(redButton);
 
        //add panel to frame
        add(buttonPanel);
 
        //create button actions
        ColorAction yellowAction = new ColorAction(Color.YELLOW);
        ColorAction blueAction = new ColorAction(Color.BLUE);
        ColorAction redAction = new ColorAction(Color.RED);
 
        yellowButton.addActionListener(yellowAction);
        blueButton.addActionListener(blueAction);
        redButton.addActionListener(redAction);
    }
 
 
    private class ColorAction implements ActionListener
    {
        public ColorAction(Color c)
        {
            backgroundColor = c;
        }
        public void actionPerfomed(ActionEvent event)
        {
            buttonPanel.setBackground(backgroundColor);
        }
 
        private Color backgroundColor;
    }
    private JPanel buttonPanel;
 
    public static final int DEFAULT_WIDTH = 300;
    public static final int DEFAULT_HEIGHT = 200;
}