import java.awt.*;
import java.applet.*;
import java.lang.*;

public class ball extends Applet implements Runnable{

   Thread thre;

   Button Restart  = new Button("Restart");
   Button Continue = new Button("Continue");
   Button Stop = new Button("Stop");

   public void init(){           /* 初期設定 */
        resize( size().width , size().height );
        setBackground(Color.white);
        setLayout(new BorderLayout());//ボーダーレイアウトに
        Panel p = new Panel();//パネル作製
        p.setLayout(new GridLayout(1,3,3,0));
        p.add(Restart);//部品をパネルに貼り付け
        p.add(Continue);
        p.add(Stop);
        add("North", p);//パネルを右に貼り付け
        Continue.disable();
        Stop.disable();
   }

     /**イベント処理*/
     public boolean handleEvent(Event e){
           if (e.target instanceof Button){
                 if ("Continue".equals(e.arg)){
                     thre.resume();
                     Restart.disable();
                     Continue.disable();
                     Stop.enable();
                 }
                 if ("Stop".equals(e.arg)){
                     thre.suspend();
                     Restart.enable();
                     Continue.enable();
                     Stop.disable();
                 }
                 if ("Restart".equals(e.arg)){
                     thre = new Thread(this);
                     thre.start();
                     Restart.disable();
                     Continue.disable();
                     Stop.enable();
                 }
                 return true;
           }
           return true;
     }

   public void run() {           /* 計算、アニメーションの中心部 */
      while(thre!=null){

            repaint();
            try{ Thread.sleep(50);}
            catch (InterruptedException e) { }
      }
   }

   public void paint(Graphics g){

   }

   public void update(Graphics g) {
         paint( g );
   }

   public void start() {
      if(thre == null){
         thre= new Thread(this);
         thre.start();
         thre.suspend();
      }
   }

   public void stop() {
      if(thre != null){
         thre.stop();
         thre=null;
      }
   }

 }