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

public class GraphPanel extends JPanel {
   int width=10;  //橢圓高度值
   int hight=10;  //橢圓寬度值

   public void paintComponent(Graphics g) {
      super.paintComponent(g);  //調用父類方法
      g.fillOval(5,5,width,hight);  //繪制橢圓
   }

   public void setW(int length){ //設置寬度
      width=(length>=0?length:10 ); 
      repaint(); //重繪組件
   }
   
   public void setH(int length){ //設置高度
      hight=(length>=0?length:10 );  
      repaint();  //重繪組件
   }   
}