/* 
 * Example code for Think Java (http://thinkapjava.com)
 *
 * Copyright(c) 2011 Allen B. Downey
 * GNU General Public License v3.0 (http://www.gnu.org/copyleft/gpl.html)
 *
 * @author Allen B. Downey
 */

import java.awt.Canvas;
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;


public class Moire extends Canvas {

    public void paint(Graphics g) {
	int i = 90;
	while (i < getWidth()) {
	    g.drawOval (0, 0, i, i);
	    i = i + 3;
	}
    }

    public static void main(String[] args) {
	// make the frame
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

	// add the canvas
	Canvas canvas = new Moire();
        canvas.setSize(400, 400);
	canvas.setBackground(Color.white);
        frame.getContentPane().add(canvas);

	// show the frame
	frame.pack();
        frame.setVisible(true);
    }
}