ColorButtons.java

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


/**
A short example of an anonymous inner class and event handling.
*/
class ColorButtons extends JFrame
{
    // Just plop the main() method right in the frame class...
    public static void main(String argv[])
    {
        ColorButtons f = new ColorButtons();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.show();
    }


    public ColorButtons()
    {
        Toolkit kit = Toolkit.getDefaultToolkit();
        Dimension ss = kit.getScreenSize();
        setSize(ss.width/3,ss.height/6);
        setLocation(ss.width/4,ss.height/4);
        setTitle("CISC370-011 -- inner classes and events");
        ButtonPanel sp = new ButtonPanel();
        Container contentPane = getContentPane();
        contentPane.add(sp);
    }
}


class ButtonPanel extends JPanel
{
    public ButtonPanel() {
        mkButton("Red",Color.RED);
        mkButton("Yellow",Color.YELLOW);
        mkButton("Green",Color.GREEN);    
    }


    void mkButton(String name,final Color bg) {
        JButton jb = new JButton(name);
        add(jb);
        jb.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e)
                { setBackground(bg); }
            });
    }
}