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

public class Coseno {
    public static void main (String[] args){
        JFrame frame = new BounceFrame();
        frame.show();
    }
}

class BounceFrame extends JFrame{
    public BounceFrame(){
        setSize(300,200);
            setTitle("Bounce");
            addWindowListener (new WindowAdapter(){
                public void windowClosing(WindowEvent e){
                    System.exit(0);
                }
            });
        
        Container contentPane = getContentPane();
        canvas = new JPanel();
        contentPane.add(canvas, "Center");
        JPanel p = new JPanel();
       // Thread.currentThread().setPriority(Thread.currentThread().MAX_PRIORITY);
        addButton(p, "Start", new ActionListener(){
            public void actionPerformed(ActionEvent evt){
                Ball b = new Ball(canvas,Color.black);
                b.setPriority(Thread.MIN_PRIORITY/*NORM_PRIORITY*/);
                b.start();
            }
        });
        addButton(p, "Expres", new ActionListener(){
            public void actionPerformed(ActionEvent evt){
                Ball b = new Ball(canvas,Color.red);
                b.setPriority(Thread.MAX_PRIORITY/*NORM_PRIORITY+2*/);
                b.start();
            }
        });
        
        
        addButton(p,"Close", new ActionListener(){
            public void actionPerformed (ActionEvent evt){
                canvas.setVisible(false);
                System.exit(0);
            }
        });
        contentPane.add(p,"South");
    }
    
    public void addButton(Container c, String title, ActionListener a){
        JButton b = new JButton(title);
        c.add(b);
        b.addActionListener(a);
    }
    private JPanel canvas;
}

class Ball extends Thread {
    public Ball (JPanel b,Color c) 
        { box = b;
        color = c;
        }
    public void draw () {
        Graphics g = box.getGraphics();
        g.setColor(color);
        g.fillOval(x,y,XSIZE, YSIZE);
        g.dispose();
    }
    
    public void move(){
        if(!box.isVisible()) return;
        Graphics g = box.getGraphics();
        g.setXORMode(box.getBackground());
        g.setColor(color);
        g.fillOval(x, y, XSIZE, YSIZE);
        x += dx;
        y +=dy;
        Dimension d = box.getSize();
        if (x<0){
            x = 0;
            dx = -dx;
        }
        if (x+XSIZE >= d.width){
            x = d.width-XSIZE; dx = - dx;
        }
        if(y<0){
            y=0;
            dy = -dy;
        }
        if (y+ YSIZE >= d.height){
            y = d.height-YSIZE;
            dy = -dy;
        }
        g.fillOval (x, y, XSIZE, YSIZE);
        //(g.dispose();
    }
    public void run (){
        try{
        draw();
        for (int i = 1; i<= 10000; i++){
            move();
            sleep(1);
        }
            }catch (InterruptedException e){}
        
    }
    
    private JPanel box;
    private static final int XSIZE = 10;
    private static final int YSIZE = 10;
    private int x = 0;
    private int y = 0;
    private int dx = 2;
    private int dy = 2;
    private Color color;
}