// RandomCircles.java
// Draw some random circles.
// Author: Henry H. Leitner
// Date: March 3, 2009

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

public class RandomCircles extends JFrame 
{
	static JButton circleButton;
	static MyCirclePanel m = new MyCirclePanel();
  
	public static void main (String args[]) 
	{
		RandomCircles fr = new RandomCircles();
		fr.setSize(450,450);
		fr.setTitle("Random Circles!");
		circleButton = new JButton("Click Here to Draw a Random Circle");
		circleButton.setFont(new Font("Helvetica", Font.BOLD, 24));
		circleButton.setBackground(Color.YELLOW);
		circleButton.setForeground(Color.RED);
		fr.getContentPane().add(circleButton, BorderLayout.NORTH);
		circleButton.addActionListener(m);
		fr.getContentPane().add(m, BorderLayout.CENTER);
		fr.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
	  	fr.setVisible(true);
	}	
 }


class MyCirclePanel extends JPanel implements ActionListener 
{    
  
  public void paintComponent (Graphics g) 
  {
    //super.paintComponent(g);
    int diameter, radius, x, y,
    size = getSize().width / 2;
  
    // Generate a random center for the circle.
    x = (int) (size * Math.random());
    y = (int) (size * Math.random());
    Color randomColor = new Color((int)(255*Math.random()),
		  (int)(255*Math.random()),
		  (int)(255*Math.random()));
    // now randomly reduce the diameter
    diameter = (int) (size * Math.random());
    radius = (int)(diameter/2);
    g.setColor(randomColor);
    g.fillOval(x-radius, y-radius, diameter, diameter);
  }
  
  
  public void actionPerformed (ActionEvent event) 
  {
	 repaint();
  }
 
}