/**
 * Creates a thread that run a cycle of red, green, yellow, red, etc.
 * lights on a traffic light.  Adds buttons to stop and start the 
 * animation.  This is in the file "example-progs/buttons/TLApplet.java"
 */

import java.applet.*;		// for Class Applet
import java.awt.*;		// for Color

public class TLApplet extends Applet implements Runnable
{
   TrafficLight trafficLight = new TrafficLight( Color.green );
   Thread tlThread = null;
   Button stop,start;		// Buttons to stop and start animation
   

   public void init()		// Applet method
   {
      System.out.println("TLApplet's init() method called");
      setLayout( new BorderLayout() );
      add( "Center", trafficLight );
      stop = new Button( "Stop" );	// Create button with Stop label
      add( "West", stop );		// Add it to the applet
      start = new Button( "Start" );	// Create button w Start label
      add( "East", start );		// and add to applet
      tlThread = new Thread( this );	// Give thread a runnable object
      tlThread.start();			// Start thread running
   }

   public void start()		// Applet method
   {
      System.out.println("TLApplet's start() method called");

      tlThread.resume();	// First time resume called on already
      start.disable();
      stop.enable();
   }				// started thread, but this causes no
				// problem
   public void stop()		// Applet method
   {
      System.out.println("TLApplet's stop() method called");
      tlThread.suspend();	 // Suspend thread when Applet is stopped.
      start.enable();
      stop.disable();
   }

   public void destroy()		// Applet method
   {
      System.out.println("TLApplet's destroy() method called");
      tlThread.stop();		 // Stop thread when Applet is terminated.
      tlThread = null;
   }

   public static void main( String arg[] ){
       Frame f = new Frame( "TL w Buttons" );
       TLApplet tl = new TLApplet();
       f.setSize(300,600);
       f.add("Center",tl);
       tl.init();
       f.show();
       tl.start();
   }

   public void run()		// Thread method
   {
      System.out.println("Entering TLApplet:run()");
      while ( true )
      {
         trafficLight.setColor( Color.red );   // Change traffic light to red
         try{ Thread.sleep(10000); }
         catch ( InterruptedException e ) {}
 
         trafficLight.setColor( Color.green ); // Change traffic light to green
         try{ Thread.sleep(10000); }
         catch ( InterruptedException e ) {}

         trafficLight.setColor( Color.yellow );// Change traffic light to yellow
         try{ Thread.sleep(5000); }
         catch ( InterruptedException e ) {}
 
      }
   }

   // Event handler for buttons
   public boolean action( Event e, Object arg ){
       if ( e.target == stop ){
           System.out.println( "Processing stop button" );
           tlThread.suspend();		// Suspend animation
           start.enable();		// Enable start button
           stop.disable();		// Disable stop button
           return true;
       }
       if ( e.target == start ){
           System.out.println( "Processing start button" );
           tlThread.resume();
           start.disable();
           stop.enable();
           return true;
       }
       return super.action( e,arg );
   }
}