/*
	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/lbloading.gif';		
var closeButton = 'images/lbclose.gif';		





//
// getPageScroll()
// Returns array with x,y page scroll values.
// Core code from - quirksmode.org
//
function getPageScroll()
{
	var yScroll;
	
	if ( self.parent.pageYOffset )
	{
		yScroll = self.parent.pageYOffset;
	}
	else if ( parent.document.documentElement && parent.document.documentElement.scrollTop ) // Explorer 6 Strict
	{
		yScroll = parent.document.documentElement.scrollTop;
	}
	else if ( parent.document.body ) // all other Explorers
	{
		yScroll = parent.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.parent.innerHeight && window.parent.scrollMaxY )
	{	
		xScroll = parent.document.body.scrollWidth;
		yScroll = window.parent.innerHeight + window.parent.scrollMaxY;
	}
	else if ( parent.document.body.scrollHeight > parent.document.body.offsetHeight ) // all but Explorer Mac
	{
		xScroll = parent.document.body.scrollWidth;
		yScroll = parent.document.body.scrollHeight;
	}
	else // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
	{
		xScroll = parent.document.body.offsetWidth;
		yScroll = parent.document.body.offsetHeight;
	}
	
	var windowWidth, windowHeight;
	
	if ( self.parent.innerHeight ) // all except Explorer
	{
		windowWidth = self.parent.innerWidth;
		windowHeight = self.parent.innerHeight;
	}
	else if ( parent.document.documentElement && parent.document.documentElement.clientHeight ) // Explorer 6 Strict Mode
	{
		windowWidth = parent.document.documentElement.clientWidth;
		windowHeight = parent.document.documentElement.clientHeight;
	}
	else if ( parent.document.body ) // other Explorers
	{
		windowWidth = parent.document.body.clientWidth;
		windowHeight = parent.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 ()
{
	parent.document.onkeypress = getKey;
}
	

//
// showLightbox()
// Preloads images. Places new image in lightbox then centers and displays.
//
function showLightbox( objLink )
{
	// prep objects
	var objOverlay = parent.document.getElementById( 'overlay' );
	var objLightbox = parent.document.getElementById( 'lightbox' );
	var objCaption = parent.document.getElementById( 'lightboxCaption' );
	var objImage = parent.document.getElementById( 'lightboxImage' );
	var objLoadingImage = parent.document.getElementById( 'loadingImage' );
	var objLightboxDetails = parent.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 = parent.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 = parent.document.getElementById( 'overlay' );
	objLightbox = parent.document.getElementById( 'lightbox' );
	
	// hide lightbox and overlay
	objOverlay.style.display = 'none';
	objLightbox.style.display = 'none';
	
	// make select boxes visible
	selects = parent.document.getElementsByTagName( 'select' );
    for ( i = 0; i != selects.length; i++ )
	{
		selects[i].style.visibility = 'visible';
	}
	
	// disable keypress listener
	parent.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 = parent.document.getElementsByTagName( 'body' ).item( 0 );
	
	// create overlay div and hardcode some functional styles (aesthetic styles are in CSS file)
	var objOverlay = parent.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 = parent.document.createElement( 'a' );
		objLoadingImageLink.setAttribute( 'href', '#' );
		
		objLoadingImageLink.onclick = function ()
		{
			hideLightbox();
			return false;
		}
		
		objOverlay.appendChild( objLoadingImageLink );
		
		var objLoadingImage = parent.document.createElement( 'img' );
		objLoadingImage.src = loadingImage;
		objLoadingImage.setAttribute( 'id', 'loadingImage' );
		objLoadingImage.style.position = 'absolute';
		objLoadingImage.style.zIndex = '150';
		objLoadingImageLink.appendChild( objLoadingImage );
		
		//	clear onLoad, as IE will flip out w/animated gifs
		imgPreloader.onload = function()
		{
		}
		
		return false;
	}
	
	imgPreloader.src = loadingImage;
	
	// create lightbox div, same note about styles as above
	var objLightbox = parent.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 = parent.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 = parent.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 = parent.document.createElement( 'img' );
	objImage.setAttribute( 'id', 'lightboxImage' );
	objLink.appendChild( objImage );
	
	// create details div, a container for the caption and keyboard message
	var objLightboxDetails = parent.document.createElement( 'div' );
	objLightboxDetails.setAttribute( 'id', 'lightboxDetails' );
	objLightbox.appendChild( objLightboxDetails );
	
	// create caption
	var objCaption = parent.document.createElement( 'div' );
	objCaption.setAttribute( 'id', 'lightboxCaption' );
	objCaption.style.display = 'none';
	objLightboxDetails.appendChild( objCaption );
	
	// create keyboard message
//	var objKeyboardMsg = parent.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