In Previous article, we have seen the life cycle of Applet.
In this example, i will dem0nstrate that how we can animate ball and bounce it around the walls.
Please give your feedback on this article, so that i can improve it in future.
import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
class Ball
{
int x,y,radius,dx,dy;
Color BallColor;
public Ball(int x,int y,int radius,int dx,int dy,Color bColor)
{
this.x=x;
this.y=y;
this.radius=radius;
this.dx=dx;
this.dy=dy;
BallColor=bColor;
}
}
public class BouncingbALL extends Applet implements Runnable{
Ball redBall,blackBall;
public void init()
{
redBall=new Ball(80,80,20,2,4,Color.red);
blackBall=new Ball(40,70,20,4,2,Color.black);
Thread t=new Thread(this);
t.start();
}
public void paint(Graphics g)
{
g.setColor(redBall.BallColor);
g.fillOval(redBall.x, redBall.y, redBall.radius, redBall.radius);
g.setColor(blackBall.BallColor);
g.fillOval(blackBall.x, blackBall.y, blackBall.radius, blackBall.radius);
}
public void run()
{
while(true)
{
try
{
displacementOperation(redBall);
displacementOperation(blackBall);
Thread.sleep(20);
repaint();
}
catch(Exception e){}
}
}
//This method checks the boundary condition of ball movement
public void displacementOperation(Ball ball)
{
if(ball.y >= 200 || ball.y <= 0)
{
ball.dy=-ball.dy;
}
if(ball.x >= 200 || ball.x <= 0)
{
ball.dx=-ball.dx;
}
ball.y=ball.y-ball.dy;
ball.x=ball.x-ball.dx;
}
}
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