import java.applet.*;
import java.awt.*;
import java.awt.image.*;
import java.lang.*;
import java.net.*;
import java.io.*;

public class LivingLink extends Applet implements Runnable{

  Image gif=null;
  int gifIndex;
  int gifX=0;
  int Height=100;
  int Width=100;
  int pauseLen=150;
  int gifWidth;
  String gifStrip=null;
  Image offScrImage;
  Graphics offScrGC=null;
  Thread kicker=null;
  boolean imageLoadError=false;
  boolean urlError=false;
  boolean debug=false;
  URL link=null;
  Color backGround;

  public void init() {
    String param;
    int r,g,b;

    param=getParameter("height");
    if (param != null)
      Height=Integer.valueOf(param).intValue();

    param=getParameter("width");
    if (param!=null)
      Width=Integer.valueOf(param).intValue();

    param=getParameter("DEBUG");
    if(param!=null)
      debug=true;

    param=getParameter("LINK");
    if(param!=null)
    {
      try
      {
        link=new URL(param);
      } catch(MalformedURLException e){urlError=true;}

    }
    
    if(debug)
    {
      if(urlError)
        System.out.println("URL Error");
      else
        System.out.println("No URL Error");
    }

    param=getParameter("GIFSTRIP");
    if(param!=null)
      gifStrip=param;

    if(debug)
    {
      if(gifStrip==null)
        System.out.println("No Gif Strip");
      else
        System.out.println("Gif Strip = " + gifStrip);
    }

    param=getParameter("PAUSE");
    if (param!=null)
      pauseLen=Integer.valueOf(param).intValue();

    r=g=b=255;
    param=getParameter("BGCOLOR");
    if(param!=null)
    {
      if(param.charAt(0)=='#')
      {
        r=readColorValue(param,1,3);
        g=readColorValue(param,3,5);
        b=readColorValue(param,5,7);
      }
    }
    
    if(debug)
        System.out.println("Colors, r="+r+" g="+g+" b="+b);

    backGround=new Color(r,g,b);
    
  }
  
  public int readColorValue(String param,int start,int stop)
  {
    String temp;

    try
    {
      temp=param.substring(start,stop);
    } catch(StringIndexOutOfBoundsException e){return 0;}

    try
    {
      return Integer.valueOf(temp,16).intValue();
    } catch(NumberFormatException e){return 0;}
  }
   
  public void paint(Graphics g)
  {  
    if(urlError)
      g.drawString("Malformed URL",10,Height/2-10);
    else if(imageLoadError)
       g.drawString("Images load error",10,Height/2-10);
     else if((offScrGC!=null))
    {
      offScrGC.fillRect(0,0,Width,Height);
      offScrGC.drawImage(gif,-1*gifX,0,this);
      g.drawImage(offScrImage,0,0,this);
    }
  }

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

  public synchronized boolean imageUpdate(Image img, int infoFlags,
                                          int x, int y,
                                          int width, int height) 
  {

    if ((infoFlags & ERROR) != 0) {
      imageLoadError = true;
    }
    notifyAll();
    return true;
  }

  public synchronized void loadImages()
  {
    gif=getImage(getCodeBase(),gifStrip);

    if (gif==null)
      imageLoadError=true;

    else
      while((gifWidth=gif.getWidth(this))<0)
      {
        try
        {
          wait();
        } catch(InterruptedException e){}
      }

    if(debug)
      System.out.println("Gif Strip Loaded");  
  }

    
  public void run() {
    int i,j;

    Thread.currentThread().setPriority(Thread.MIN_PRIORITY);

    loadImages();

    offScrImage=createImage(Width,Height);
    offScrGC=offScrImage.getGraphics();
    offScrGC.setColor(backGround);

    repaint();

    for(i=0;i<40;i++)
    {
      try
      {
        kicker.sleep(50);
      } catch (InterruptedException e){}
    }

    repaint();

    while(true)
    {
      gifX+=Width;

      if (gifX>(gifWidth-Width))
        gifX=0;

      if(debug)
        System.out.println("gifX ="+gifX);

      repaint();
      try
      {
        kicker.sleep(pauseLen);
      } catch (InterruptedException e){}
    
    }
  }
  
  public void start() {
    if (kicker == null) {
      kicker = new Thread(this);
      kicker.start();
    }
  }

  public void stop() {
    kicker.stop();
    kicker = null;
  }
  
  public boolean mouseDown(Event evt,int x, int y)
  {
    if(debug)
      System.out.println("Mouse Click");

    if(link!=null)
    {
      if(debug)
        System.out.println("Launching URL");

      getAppletContext().showDocument(link);
      return true;     
    }
    
    if(debug)
      System.out.println("No URL to launch");

    return false;
  }

}