/*
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 = '/images/loading.gif';
var closeButton = '/images/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'; }



// Hide select boxes as they will 'peek' through the image in IE

selects = document.getElementsByTagName("select");

for (i = 0; i != selects.length; i++) {

selects[i].style.visibility = "hidden";

}





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';



// make select boxes visible

selects = document.getElementsByTagName("select");

for (i = 0; i != selects.length; i++) {

selects[i].style.visibility = "visible";

}



// 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 <a href="#" onclick="hideLightbox(); return false;"><kbd>x</kbd></a> 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