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


public class AnimEx6 extends Applet implements Runnable {
    int frame;
    int delay;
    int step1=5,step2=2;
    Thread animator;

    Dimension offDimension;
    Image offImage;
    Graphics offGraphics;

    Image image[] = new Image[2];
    AudioClip clip;


    public void init() {
		String str = getParameter("fps");
		int fps = (str != null) ? Integer.parseInt(str) : 10;
		delay = (fps > 0) ? (1000 / fps) : 100;
		image[0] = getImage(getCodeBase(),"images/T6.gif");
		image[1] = getImage(getCodeBase(),"images/T7.gif");
		clip = getAudioClip(getCodeBase(),"images/bubble.au");

    }

    /**
     Create a thread and start it.
     */
    public void start() {
		animator = new Thread(this);
		animator.start();
    }

    /**
     * the main animation.
     */
    public void run() {
		// Remember the starting time
		long tm = System.currentTimeMillis();
		while (Thread.currentThread() == animator) {
	    	// Display the next frame of animation.
	    	repaint();

	    	// Delay depending on how far we are behind.
	    	try {
		   tm += delay;
		   Thread.sleep(Math.max(0,tm-System.currentTimeMillis()));
	    	} catch (InterruptedException e) {break;  }

	    	// Advance the frame
	    	frame++;
		}
    }

    /**
     * called when the applet is no longer visible. 
     */
    public void stop() {
		animator = null;
		offImage = null;
		offGraphics = null;
    }

    /**
     * Update a frame of animation.
     */
    public void update(Graphics g) {
    	Color fgr=getForeground();
	Dimension d = getSize();

	// Create the offscreen graphics context
	if ((offGraphics == null)
	 	  || (d.width != offDimension.width)
	 	  || (d.height != offDimension.height)) 
	{	offDimension = d;
	    	offImage = createImage(d.width, d.height);
	    	offGraphics = offImage.getGraphics();
	}

	// Erase the previous image
	offGraphics.setColor(getBackground());
	offGraphics.fillRect(0, 0, d.width, d.height);
	offGraphics.setColor(fgr);

	// Paint the frame into the image
	paintFrame(offGraphics);

	// Paint the image onto the screen
	g.drawImage(offImage, 0, 0, this);
    }


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

    /**
     * Paint a frame of animation.
     */
    public void paintFrame(Graphics g) {
	int wdth = getSize().width;
	int hght = getSize().height;
	if((image[0].getWidth(this) > 0) &&
	   (image[0].getHeight(this) > 0) &&
	   (image[1].getWidth(this) > 0) &&
	   (image[1].getHeight(this) > 0) )
	{    //the image is loaded
	  g.drawImage(image[frame%2],wdth-((frame*step1)%wdth),hght/4,this);
          if(wdth-((frame*step1)%wdth)<=step1) clip.play();
	  g.drawImage(image[frame%2],(frame*step2)%wdth,hght/2,this);
	  if((frame*step2)%wdth<step2) clip.play();		 
	}
    }
}