/*-----------------------------------------------------------------*\

	AdBanner Applet - by Jay Tomlin
	Multiple-image slide show... each image has its own
	associated URL, to which the user is sent upon clicking
	(the URL target changes with the image)

	Usage:
	<applet width=w height=h code=AdBanner.class>
	<param name=imageArray value="img1.gif,img2.gif, ...imgn.gif">
	<param name=urlArray value="http://url1/, ...http://urln">
	<param name=targetWindow value="_top">
	<param name=frameDelay value="5">
 	</applet>

	For best results, the width w and height h of the applet should
	match the dimensions of the images, all of which should be the 
	same size.

	The number of images need not equal the number of URLs--a
 	difference between the two results in an interesting pattern
 	of offset--but when the same number of each is provided, clicking
	on an image loads its associated URL 
	  - into the main browser window if 'targetWindow' is set
	    to "_top" or left blank
	 or
	  - into the specified window (or frame) if 'targetWindow' is set to any
	    other value
	The time interval between frame changes, in integer seconds, is indicated
 	by the frameDelay parameter. 

 
\*-----------------------------------------------------------------*/

import java.applet.*;
import java.awt.*;
import java.net.*;
import java.util.*;

public class AdBanner extends java.applet.Applet implements Runnable {

// Declare the class variables

String imageArray, urlArray, targetWindow;
StringTokenizer imageTokens, urlTokens;
int frameDelay, currentImage, currentURL, imageCount, urlCount;
Image IMAGES[];
URL URLS[];
Thread kicker;

public void init() {

  // Get parameters from HTML Tag, providing defaults where appropriate
  imageArray = getParameter("imageArray");
  urlArray = getParameter("urlArray");
  targetWindow = getParameter("targetWindow");
  frameDelay = new Integer(getParameter("frameDelay")).intValue();
  if (frameDelay == 0) { frameDelay = 5; } // default 5 second delay
  if (targetWindow==null) { targetWindow = "_top";} // default to main window
  // Come to my place if you need help:
  if (urlArray==null) { urlArray = "http://php.indiana.edu/~ltomlin/java.html"; }

  // Split the imageArray and urlArray into tokens
  String delim = new String(",");
  imageTokens = new StringTokenizer(imageArray, delim, false); 
  urlTokens = new StringTokenizer(urlArray, delim, false); 

  // Now create two arrays, IMAGES, and URLS (to hold Image & URL objects) 
  // 1. Create the Image array object with the proper number of images:
  IMAGES = new Image[imageTokens.countTokens()]; 
  int i=0;
  while(imageTokens.hasMoreTokens()) { 
    getAppletContext().showStatus("Loading image " + i+1);
    try { String picture = imageTokens.nextToken().toString();
	  IMAGES[i] = getImage(getCodeBase(), picture);
	  i++; } 
		catch (NoSuchElementException e) {;}
	} // ends while()

  // 2. Create the URL array object with the proper number of URLs:
  URLS = new URL[urlTokens.countTokens()];
  int j=0;
  while(urlTokens.hasMoreElements()) { 
     try   {
	  try { 
		URLS[j] = new URL(urlTokens.nextElement().toString());
	  	j++; 
	      } catch (MalformedURLException e) {;}
	  } 
	  catch (NoSuchElementException e) {;}
    } // ends while()

  imageCount = i; // the total actaul number of images loaded (no offset)
  urlCount = j;   // the total actual number of URLs loaded (no offset)
  currentImage = 0;
  currentURL = 0;

} // ends init() 

public void start() {           
  // Start the thread going
	if (kicker == null) {
		kicker = new Thread(this);
		kicker.start(); // starts the run() method
	} // ends if
}        // ends start()

public void paint(Graphics g) {
	update(g); // this should reduce flicker
} // ends paint()

public void update(Graphics g) {
    if (IMAGES[currentImage] != null) {
	g.drawImage(IMAGES[currentImage], 0, 0, this);	
    } // ends unless()
} //ends update()

public boolean handleEvent(Event e) {

  // When the mouse is over the applet, display the currentURL in the browser's Status Window
    if (e.id == Event.MOUSE_MOVE) {
	this.getAppletContext().showStatus(URLS[currentURL].toString());
    } // ends if

  // On click, open the current URL in the target Window:
    if (e.id == Event.MOUSE_UP) { // not mouse down!
	this.getAppletContext().showDocument(URLS[currentURL], targetWindow);
    } // ends if

  // When the mouse leaves the applet, clear the browser's Status Window
    if (e.id == Event.MOUSE_EXIT) {
	this.getAppletContext().showStatus("");
    } // ends if

    return true;
} // ends handleEvent()

public void run() {
    while (kicker != null) {
	// slide-show thread goes here
	for(;;) { // loop forever
	    if (currentImage >= imageCount) { currentImage=0; }
	    if (currentURL >= urlCount) { currentURL=0; }
	    repaint();
	try {
	    kicker.sleep(1000 * frameDelay);
	    } catch (InterruptedException e) {;}
	    currentImage++;
	    currentURL++;

	} // ends for(;;)

     } // ends while()
} // ends run()

public void stop() { kicker = null; }

} //////////////////////////////////////////////////////////////////////// ends class