TennisGame.java

// Source File Name:   TennisGame.java

import java.awt.Container;
import javax.swing.JFrame;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import javax.swing.JPanel;


class TennisGame
{

    TennisGame()
    {
    }

    public static void main(String args[])
    {
        JFrame jframe = new JFrame();
        jframe.setTitle("Tennis");
        jframe.setSize(640, 480);
        jframe.setDefaultCloseOperation(3);
        MyPanel mypanel = new MyPanel();
        jframe.getContentPane().add(mypanel);
        jframe.setVisible(true);
    }
}


class MyPanel extends JPanel
    implements Runnable, MouseMotionListener
{
    Ball ball;
    Racket racket;
    boolean lose;

    public MyPanel()
    {
        setBackground(Color.white);
        addMouseMotionListener(this);
        ball = new Ball(100, 100, 5, 3, 0, 0, 610, 430, 20);
        racket = new Racket(300, 400, 100, 10);
        lose = false;
        Thread thread = new Thread(this);
        thread.start();
    }

    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        ball.forward();

//        if( ... ){
//            ball.bounce();
//        }

//        if(ball.getY() > racket.getY() + 10)  {
//            g.setColor(Color.black);
//            g.drawString("You lose", 290, 220);
//            lose = true;
//        }

        g.setColor(Color.red);
        g.fillOval(ball.getX(), ball.getY(), ball.getDiameter(), ball.getDiameter());
        g.setColor(Color.gray);
        g.fillRect(racket.getX(), racket.getY(), racket.getWidth(), racket.getHeight());
    }

    public void mouseDragged(MouseEvent mouseevent)
    {
    }

    public synchronized void mouseMoved(MouseEvent mouseevent)
    {
        racket.setX(mouseevent.getX());
    }

    public void run()
    {
        do
        {
            do
            {
                repaint();
                try
                {
                    Thread.sleep(10L);
                }
                catch(Exception exception) { }
            } while(!lose);
            try
            {
                Thread.sleep(5000L);
            }
            catch(Exception exception1) { }
            System.exit(0);
        } while(true);
    }

}


class Ball
{
    private int x;
    private int y;
    private int vx;
    private int vy;
    private int left;
    private int right;
    private int top;
    private int bottom;
    private int diameter;

    public Ball(int i, int j, int k, int l, int i1, int j1, int k1,
            int l1, int i2)
    {
        x = i;
        y = j;
        vx = k;
        vy = l;
        right = k1;
        left = i1;
        top = j1;
        bottom = l1;
        diameter = i2;
    }

    public void forward()
    {
        x = x + vx;
        y = y + vy;
        if(x < left || x > right)
            vx = -vx;
        if(y < top || y > bottom)
            vy = -vy;
    }

    public void bounce()
    {
        vy = -vy;
        forward();
    }

    public int getX()
    {
        return x;
    }

    public void setX(int i)
    {
        x = i;
    }

    public int getY()
    {
        return y;
    }

    public void setY(int i)
    {
        y = i;
    }

    public int getDiameter()
    {
        return diameter;
    }

}



class Racket
{
    int x;
    int y;
    int width;
    int height;

    public Racket(int i, int j, int k, int l)
    {
        x = i;
        y = j;
        width = k;
        height = l;
    }

    public void setX(int i)
    {
        x = i;
    }

    public int getX()
    {
        return x;
    }

    public void setY(int i)
    {
        y = i;
    }

    public int getY()
    {
        return y;
    }

    public int getWidth()
    {
        return width;
    }

    public int getHeight()
    {
        return height;
    }

}