/*
 Lightbox JS: Fullsize Image Overlays 
 by Lokesh Dhakar - http://www.huddletogether.com
 For more information on this script, visit:
 http://huddletogether.com/projects/lightbox/
 Licensed under the Creative Commons Attribution 2.5 License - http://creativecommons.org/licenses/by/2.5/
 (basically, do anything you want, just leave my name and link)
 
 Table of Contents
 -----------------
 Configuration
 
 Functions
 - getPageScroll()
 - getPageSize()
 - pause()
 - getKey()
 - listenKey()
 - showLightbox()
 - hideLightbox()
 - initLightbox()
 - addLoadEvent()
 
 Function Calls
 - addLoadEvent(initLightbox)
*/

//
// Configuration
//
// If you would like to use a custom loading image or close button reference them in the next two lines.
var loadingImage = '/transformation/cssimages/loading.gif';  
var closeButton = '/transformation/cssimages/close.gif';  


//
// getPageScroll()
// Returns array with x,y page scroll values.
// Core code from - quirksmode.org
//
function getPageScroll(){
 var yScroll;
 if (self.pageYOffset) {
  yScroll = self.pageYOffset;
 } else if (document.documentElement && document.documentElement.scrollTop){  // Explorer 6 Strict
  yScroll = document.documentElement.scrollTop;
 } else if (document.body) {// all other Explorers
  yScroll = document.body.scrollTop;
 }
 arrayPageScroll = new Array('',yScroll) 
 return arrayPageScroll;
}

//
// getPageSize()
// Returns array with page width, height and window width, height
// Core code from - quirksmode.org
// Edit for Firefox by pHaez
//
function getPageSize(){
 
 var xScroll, yScroll;
 
 if (window.innerHeight && window.scrollMaxY) { 
  xScroll = document.body.scrollWidth;
  yScroll = window.innerHeight + window.scrollMaxY;
 } else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
  xScroll = document.body.scrollWidth;
  yScroll = document.body.scrollHeight;
 } else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
  xScroll = document.body.offsetWidth;
  yScroll = document.body.offsetHeight;
 }
 
 var windowWidth, windowHeight;
 if (self.innerHeight) { // all except Explorer
  windowWidth = self.innerWidth;
  windowHeight = self.innerHeight;
 } else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
  windowWidth = document.documentElement.clientWidth;
  windowHeight = document.documentElement.clientHeight;
 } else if (document.body) { // other Explorers
  windowWidth = document.body.clientWidth;
  windowHeight = document.body.clientHeight;
 } 
 
 // for small pages with total height less then height of the viewport
 if(yScroll < windowHeight){
  pageHeight = windowHeight;
 } else { 
  pageHeight = yScroll;
 }
 // for small pages with total width less then width of the viewport
 if(xScroll < windowWidth){ 
  pageWidth = windowWidth;
 } else {
  pageWidth = xScroll;
 }

 arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight) 
 return arrayPageSize;
}

//
// pause(numberMillis)
// Pauses code execution for specified time. Uses busy code, not good.
// Code from http://www.faqts.com/knowledge_base/view.phtml/aid/1602
//
function pause(numberMillis) {
 var now = new Date();
 var exitTime = now.getTime() + numberMillis;
 while (true) {
  now = new Date();
  if (now.getTime() > exitTime)
   return;
 }
}
//
// getKey(key)
// Gets keycode. If 'x' is pressed then it hides the lightbox.
//
function getKey(e){
 if (e == null) { // ie
  keycode = event.keyCode;
 } else { // mozilla
  keycode = e.which;
 }
 key = String.fromCharCode(keycode).toLowerCase();
 
 if(key == 'x'){ hideLightbox(); }
}

//
// listenKey()
//
function listenKey () { document.onkeypress = getKey; }
 
//
// showLightbox()
// Preloads images. Pleaces new image in lightbox then centers and displays.
//
function showLightbox(objLink)
{
 // prep objects
 var objOverlay = document.getElementById('overlay');
 var objLightbox = document.getElementById('lightbox');
 var objCaption = document.getElementById('lightboxCaption');
 var objImage = document.getElementById('lightboxImage');
 var objLoadingImage = document.getElementById('loadingImage');
 var objLightboxDetails = document.getElementById('lightboxDetails');
 
 var arrayPageSize = getPageSize();
 var arrayPageScroll = getPageScroll();
 // center loadingImage if it exists
 if (objLoadingImage) {
  objLoadingImage.style.top = (arrayPageScroll[1] + ((arrayPageSize[3] - 35 - objLoadingImage.height) / 2) + 'px');
  objLoadingImage.style.left = (((arrayPageSize[0] - 20 - objLoadingImage.width) / 2) + 'px');
  objLoadingImage.style.display = 'block';
 }
 // set height of Overlay to take up whole page and show
 objOverlay.style.height = (arrayPageSize[1] + 'px');
 objOverlay.style.display = 'block';
 // preload image
 imgPreload = new Image();
 imgPreload.onload=function(){
  objImage.src = objLink.href;
  // center lightbox and make sure that the top and left values are not negative
  // and the image placed outside the viewport
  var lightboxTop = arrayPageScroll[1] + ((arrayPageSize[3] - 35 - imgPreload.height) / 2);
  var lightboxLeft = ((arrayPageSize[0] - 20 - imgPreload.width) / 2);
  
  objLightbox.style.top = (lightboxTop < 0) ? "0px" : lightboxTop + "px";
  objLightbox.style.left = (lightboxLeft < 0) ? "0px" : lightboxLeft + "px";

  objLightboxDetails.style.width = imgPreload.width + 'px';
  
  if(objLink.getAttribute('title')){
   objCaption.style.display = 'block';
   //objCaption.style.width = imgPreload.width + 'px';
   objCaption.innerHTML = objLink.getAttribute('title');
  } else {
   objCaption.style.display = 'none';
  }
  
  // A small pause between the image loading and displaying is required with IE,
  // this prevents the previous image displaying for a short burst causing flicker.
  if (navigator.appVersion.indexOf("MSIE")!=-1){
   pause(250);
  } 
  if (objLoadingImage) { objLoadingImage.style.display = 'none'; }
  objLightbox.style.display = 'block';
  // After image is loaded, update the overlay height as the new image might have
  // increased the overall page height.
  arrayPageSize = getPageSize();
  objOverlay.style.height = (arrayPageSize[1] + 'px');
  
  // Check for 'x' keypress
  listenKey();
  return false;
 }
 imgPreload.src = objLink.href;
 
}


//
// hideLightbox()
//
function hideLightbox()
{
 // get objects
 objOverlay = document.getElementById('overlay');
 objLightbox = document.getElementById('lightbox');
 // hide lightbox and overlay
 objOverlay.style.display = 'none';
 objLightbox.style.display = 'none';
 
 // disable keypress listener
 document.onkeypress = '';
}


//
// initLightbox()
// Function runs on window load, going through link tags looking for rel="lightbox".
// These links receive onclick events that enable the lightbox display for their targets.
// The function also inserts html markup at the top of the page which will be used as a
// container for the overlay pattern and the inline image.
//
function initLightbox()
{
 
 if (!document.getElementsByTagName){ return; }
 var anchors = document.getElementsByTagName("a");
 // loop through all anchor tags
 for (var i=0; i<anchors.length; i++){
  var anchor = anchors[i];
  if (anchor.getAttribute("href") && (anchor.getAttribute("rel") == "lightbox")){
   anchor.onclick = function () {showLightbox(this); return false;}
  }
 }
 // the rest of this code inserts html at the top of the page that looks like this:
 //
 // <div id="overlay">
 //  <a href="#" onclick="hideLightbox(); return false;"><img id="loadingImage" /></a>
 // </div>
 // <div id="lightbox">
 //  <a href="#" onclick="hideLightbox(); return false;" title="Click anywhere to close image">
 //   <img id="closeButton" />  
 //   <img id="lightboxImage" />
 //  </a>
 //  <div id="lightboxDetails">
 //   <div id="lightboxCaption"></div>
 //   <div id="keyboardMsg"></div>
 //  </div>
 // </div>
 
 var objBody = document.getElementsByTagName("body").item(0);
 
 // create overlay div and hardcode some functional styles (aesthetic styles are in CSS file)
 var objOverlay = document.createElement("div");
 objOverlay.setAttribute('id','overlay');
 objOverlay.onclick = function () {hideLightbox(); return false;}
 objOverlay.style.display = 'none';
 objOverlay.style.position = 'absolute';
 objOverlay.style.top = '0';
 objOverlay.style.left = '0';
 objOverlay.style.zIndex = '90';
  objOverlay.style.width = '100%';
 objBody.insertBefore(objOverlay, objBody.firstChild);
 
 var arrayPageSize = getPageSize();
 var arrayPageScroll = getPageScroll();
 // preload and create loader image
 var imgPreloader = new Image();
 
 // if loader image found, create link to hide lightbox and create loadingimage
 imgPreloader.onload=function(){
  var objLoadingImageLink = document.createElement("a");
  objLoadingImageLink.setAttribute('href','#');
  objLoadingImageLink.onclick = function () {hideLightbox(); return false;}
  objOverlay.appendChild(objLoadingImageLink);
  
  var objLoadingImage = document.createElement("img");
  objLoadingImage.src = loadingImage;
  objLoadingImage.setAttribute('id','loadingImage');
  objLoadingImage.style.position = 'absolute';
  objLoadingImage.style.zIndex = '150';
  objLoadingImageLink.appendChild(objLoadingImage);
  imgPreloader.onload=function(){}; // clear onLoad, as IE will flip out w/animated gifs
  return false;
 }
 imgPreloader.src = loadingImage;
 // create lightbox div, same note about styles as above
 var objLightbox = document.createElement("div");
 objLightbox.setAttribute('id','lightbox');
 objLightbox.style.display = 'none';
 objLightbox.style.position = 'absolute';
 objLightbox.style.zIndex = '100'; 
 objBody.insertBefore(objLightbox, objOverlay.nextSibling);
 
 // create link
 var objLink = document.createElement("a");
 objLink.setAttribute('href','#');
 objLink.setAttribute('title','Click to close');
 objLink.onclick = function () {hideLightbox(); return false;}
 objLightbox.appendChild(objLink);
 // preload and create close button image
 var imgPreloadCloseButton = new Image();
 // if close button image found, 
 imgPreloadCloseButton.onload=function(){
  var objCloseButton = document.createElement("img");
  objCloseButton.src = closeButton;
  objCloseButton.setAttribute('id','closeButton');
  objCloseButton.style.position = 'absolute';
  objCloseButton.style.zIndex = '200';
  objLink.appendChild(objCloseButton);
  return false;
 }
 imgPreloadCloseButton.src = closeButton;
 // create image
 var objImage = document.createElement("img");
 objImage.setAttribute('id','lightboxImage');
 objLink.appendChild(objImage);
 
 // create details div, a container for the caption and keyboard message
 var objLightboxDetails = document.createElement("div");
 objLightboxDetails.setAttribute('id','lightboxDetails');
 objLightbox.appendChild(objLightboxDetails);
 // create caption
 var objCaption = document.createElement("div");
 objCaption.setAttribute('id','lightboxCaption');
 objCaption.style.display = 'none';
 objLightboxDetails.appendChild(objCaption);
 // create keyboard message
 var objKeyboardMsg = document.createElement("div");
 objKeyboardMsg.setAttribute('id','keyboardMsg');
 objKeyboardMsg.innerHTML = 'press <kbd>x</kbd> to close';
 objLightboxDetails.appendChild(objKeyboardMsg);

}


//
// addLoadEvent()
// Adds event to window.onload without overwriting currently assigned onload functions.
// Function found at Simon Willison's weblog - http://simon.incutio.com/
//
function addLoadEvent(func)
{ 
 var oldonload = window.onload;
 if (typeof window.onload != 'function'){
     window.onload = func;
 } else {
  window.onload = function(){
  oldonload();
  func();
  }
 }
}

addLoadEvent(initLightbox); // run initLightbox onLoad