مساعدة في الجرافيك

import javax.swing.*;
import java.awt.event.*;
class circ2 extends JFrame implements ActionListener{
int xc=250, yc=250, i=10, m=150;
Timer t;
public circ2(){
super("Circle");
t=new Timer(700,this);
setSize(500,500);
setVisible(true);
t.start();
}

public void paint (Graphics g){


super.paint(g);
if(i<=150)
g.drawOval(xc-i,yc-i,i*2,i*2);
else
g.drawOval(xc-m,yc-m,m*2,m*2);


}

public void actionPerformed (ActionEvent event){
i+=10;
if(i<=150)
repaint();


else
{
m-=10;
if(m>=0)
repaint();


else
t.stop();
}



}

public static void main (String args[])
{
new circ2();
}
}

import java.awt.*;