// AnimationFun demo
// code borrowed from 
// http://www.dgp.toronto.edu/~mjmcguff/learn/java/06-threads/

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

public class AnimationFun extends Applet implements Runnable // NOTE: Applet not JApplet
{
   Thread t = null;
   boolean threadSuspended;
   int x, y;


   public void start()
   {    
      if (t == null)
      {
         t = new Thread(this);
         threadSuspended = false;
         t.start();
      }
      else 
      {
         if (threadSuspended)			// notifying the thread
         {
            threadSuspended = false;
            
            synchronized(this)
            {
               notify();
            }
         }
      }
   }

   // Executed whenever the browser leaves the page containing the applet.
   public void stop()
   {
      threadSuspended = true;
   }

   // Executed within the thread that this applet created.
   public void run()
   { 
      try
      {
         while (true) 
         {

            // Here's where the thread does some work
            if (x + 10 > 250)
            	t.interrupt();					// the interrupt method stops a timer
            else
            	x += 10;
			
            
            if ( threadSuspended )			 // thread checks to see if it should suspend itself
            {
               synchronized( this ) 
               {
                  while ( threadSuspended ) 
                  {
                     wait();
                  }
               }
            }
            
            repaint();
            t.sleep( 1000 );  				// pause for 1 second
         }
      }
      catch (InterruptedException e) { }
   }

   public void paint(Graphics g) 
   {
      g.setColor(Color.red);
      g.fillRect(x, y, 40, 40);
   }
}