/*File Animate04.java
Revised 01/07/03

Illustrates frame animation.  Stick figure
dances when user point to the image with the
mouse.  Stick figure stops dancing when mouse 
pointer exits the image.

Also illustrates:
  Event-driven programming
  Multi-threaded programming
  Ordinary inner classes
  Anonymous inner classes
  Image icons

Tested using SDK 1.4.1 under Win 2000.
************************************************/
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class Animate04 extends JFrame{
  Thread animate;//Store ref to animation thread
  ImageIcon images[] = {//An array of images
  	new ImageIcon("java1470a.gif"),
    new ImageIcon("java1470b.gif"),
    new ImageIcon("java1470c.gif")};
  JLabel label = new JLabel(images[0]);

  //-------------------------------------------//
  public Animate04(){//constructor

    getContentPane().add(label);
    
    //Use an anonymous inner class to register a
    // mouse listener
    getContentPane().addMouseListener(
      new MouseAdapter(){
        public void mouseEntered(MouseEvent e){
          //Get a new animation thread and start
          // the animation on it.
          animate = new Animate();
          animate.start();
        }//end mouseEntered

        public void mouseExited(MouseEvent e){
          //Terminate the animation.    
          animate.interrupt();
          //Let the thread die a natural death.
          // Then make it eligible for garbage
          // collection.
          while (animate.isAlive()){}//loop;
          animate = null;
          //Restore default image.
          label.setIcon(images[0]);
          label.repaint();
        }//end MouseExited
      }//end new MouseAdapter
    );//end addMouseListener()
    //End definition of anonymous inner class

    setDefaultCloseOperation(EXIT_ON_CLOSE);    
    setTitle("Copyright 2003, R.G.Baldwin");
    setSize(250,200);
    setVisible(true);

  }//end constructor
  //-------------------------------------------//

  public static void main(String[] args){
    new Animate04();
  }//end main
  //-------------------------------------------//

  //Ordinary inner class to animate the image
  class Animate extends Thread{

    public void run(){//begin run method
      try{
      	//The following code will continue to
      	// loop until the animation thread is
      	// interrupted by the mouseExited
      	// method.
        while(true){
          //Display several images in succession.
          display(1,500);
          display(0,500);
          display(2,500);
          display(0,500);
        }//end while loop
      }catch(Exception ex){
        if(ex instanceof InterruptedException){
          //Do nothing. This exception is
          // expected on mouseExited.
        }else{//Unexpected exception occurred.
          System.out.println(ex);
          System.exit(1);//terminate program
        }//end else
      }//end catch
    }//end run
    //-----------------------------------------//
    
    //This method displays an image and sleeps
    // for a prescribed period of time.  It
    // terminates and throws an
    // InterruptedException when interrupted
    // by the mouseExited method.
    void display(int image,int delay) 
                    throws InterruptedException{
      //Select and display an image.
      label.setIcon(images[image]);
      label.repaint();
      //Check interrupt status.  If interrupted
      // while not asleep, force animation to
      // terminate.
      if(Thread.currentThread().interrupted())
        throw(new InterruptedException());
      //Delay specified number of msec.
      //Terminate animation automatically if
      // interrupted while asleep.
      Thread.currentThread().sleep(delay);
    }//end display method
    //-----------------------------------------//
  }//end inner class named Animate

}//end class Animate04