//ButtonDemo.java

import javax.swing.JButton;
import javax.swing.JFrame;
import java.awt.Color;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

/**
 * Simple demonstration of putting buttons in a JFrame window.
 */
public class ButtonDemo
    extends JFrame
    implements ActionListener
{
    public static final int WIDTH = 400;
    public static final int HEIGHT = 300;

    public ButtonDemo()
    {
        setSize(WIDTH, HEIGHT);
        WindowDestroyer listener = new WindowDestroyer();
        addWindowListener(listener);

        Container contentPane = getContentPane();
        contentPane.setBackground(Color.WHITE);

        contentPane.setLayout(new FlowLayout());

        JButton sunnyButton = new JButton("Sunny");
        sunnyButton.addActionListener(this);
        contentPane.add(sunnyButton);

        JButton cloudyButton = new JButton("Cloudy");
        cloudyButton.addActionListener(this);
        contentPane.add(cloudyButton);
    }

    public void actionPerformed
    (
        ActionEvent e
    )
    {
        String actionCommand = e.getActionCommand();
        Container contentPane = getContentPane();

        if (actionCommand.equals("Sunny"))
            contentPane.setBackground(Color.BLUE);
        else if (actionCommand.equals("Cloudy"))
            contentPane.setBackground(Color.GRAY);
        else
            System.out.println("Error in button interface.");
    }
}