import javax.swing.JFrame;
import java.awt.event.KeyListener;
import java.awt.event.KeyEvent;
import java.awt.Color;
import javax.swing.JPanel;
import java.awt.Graphics;
public class MyBall extends JFrame{
ballPanel bp;
public MyBall(){
bp=new ballPanel();
Thread t=new Thread(bp);
t.start();
bp .addKeyListener(bp);
this.addKeyListener(bp);
this.add(bp);
this.setSize(400,500);
// this.setBackground(new Color(50,200,120));
// this.setLocationRelativeTo(null);
this.setLocation(300,100);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args){
MyBall my=new MyBall();
my.setVisible(true);
}
}
class ballPanel extends JPanel implements Runnable,KeyListener{
private int x=50;
private int y=50;
int flag=0;
public ballPanel(){
this.setBackground(new Color(50,200,120));
}
public void paint(Graphics g){
super.paint(g);
g.fillOval(x, y,30,30);
}
public void keyPressed(KeyEvent e){
if(e.getKeyCode()==37){
x--;
}
if(e.getKeyCode()==38){
y--;
}
if(e.getKeyCode()==39){
x++;
}
if(e.getKeyCode()==40){
y++;
}
// System.out.println(e.getKeyChar());
this.repaint();
}
public void keyReleased(KeyEvent e){
}
public void keyTyped(KeyEvent e){
}
public void run(){
while(true){
if(flag==0){
x++;
y++;
}
if(flag==1){
x--;
y++;
}
if(flag==2){
x--;
y--;
}
if(flag==3){
x++;
y--;
}
if(x>340){
if(flag==0){
flag=1;
}else{
flag=2;
}
}
if(y>430){
if(flag==1){
flag=2;
}else{
flag=3;
}
}
if(x<0){
if(flag==2){
flag=3;
}else{
flag=0;
}
}
if(y<0){
if(flag==3){
flag=0;
}else{
flag=1;
}
}
try{
Thread.sleep(5);
}catch(Exception e){
}
this.repaint();
}
}
}