/*
	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	= '/Immagini/Decorazioni/loading.gif';		
var closeButton	= '/Immagini/Decorazioni/closelabel.gif';	
var prevButton		= '/Immagini/Decorazioni/prev.gif';	
var nextButton		= '/Immagini/Decorazioni/next.gif';	


//
// 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 objIndex	 			= document.getElementById('lightboxIndex');
	var objImage 				= document.getElementById('lightboxImage');
	var objLoadingImage 		= document.getElementById('loading_Image');
	var objMes					= document.getElementById('lightboxMes');
	var objLightboxDetails 	= document.getElementById('lightboxDetails');
	var objDDL					= document.getElementById('criterio');
	var objPrev 				= document.getElementById('prevButton');
	var objNext		 			= document.getElementById('nextButton');
	
	
	var arrayPageSize 	= getPageSize();
	var arrayPageScroll 	= getPageScroll();
	
	if (objDDL) objDDL.style.display = 'none';
	
	// center loadingImage if it exists
	if (objLoadingImage) {
		objLoadingImage.style.top 	= (arrayPageScroll[1] + ((arrayPageSize[3] - 35 - objLoadingImage.height) / 2) + 'px');		
		objMes.style.top 				= (arrayPageScroll[1] + ((arrayPageSize[3] - 35 - objLoadingImage.height) / 2 + 10) + 'px');
	}

	// 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.getAttribute('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*/100 - 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('imgtitle') || objLink.getAttribute('title')) {
													objCaption.style.display	= 'block';
													objCaption.style.width 		= (imgPreload.width - 100) + 'px';
													objCaption.innerHTML 		= (objLink.getAttribute('imgtitle')) ? objLink.getAttribute('imgtitle') : objLink.getAttribute('title');
												} 
												else {
													objCaption.style.display 	= 'none';
												}
		
												if (objLink.getAttribute('date') || objLink.getAttribute('author')) {
													objIndex.style.display		= 'block';
													//objCaption.style.width = imgPreload.width + 'px';
													objIndex.innerHTML			= "<strong>Data:</strong>" + objLink.getAttribute('date') + "<strong>Autore:</strong>" + objLink.getAttribute('author');
												} 
												else {
													objIndex.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');
		
											// ###############################################################################################################################
												if (document.getElementById('xImageList')) {
													var objImgListArray	= document.getElementById('xImageList').childNodes;
													var lsCurrentIDImg	= objLink.getAttribute('idImg');
													var liPosCurrentImg	= 0;
																	
													// Cerco l'immagine corrente
													for (liPosCurrentImg = 0; liPosCurrentImg < objImgListArray.length; liPosCurrentImg++) {
														if (objImgListArray[liPosCurrentImg].getAttribute('idImg') == lsCurrentIDImg) break;
													}
													
													//Gestione pulsante prev
													if (liPosCurrentImg > 0) {
														objPrev.style.display 	= "block";
														objPrev.onclick			= function()	{ 	document.getElementById('lightbox').style.display = "none";
																												showLightbox(objImgListArray[liPosCurrentImg - 1]); 
																											}
													}
													else {
														objPrev.style.display = "none";
													}
													
													//Gestione pulsante next
													if (liPosCurrentImg < objImgListArray.length - 1) {
														objNext.style.display 	= "block";
														objNext.onclick			= function()	{ 	document.getElementById('lightbox').style.display = "none";
																												showLightbox(objImgListArray[liPosCurrentImg + 1]); 
																											}
													}
													else {
														objNext.style.display = "none";
													}
												}
												else {
													objPrev.style.display = "none";
													objNext.style.display = "none";
												}
											// ###############################################################################################################################		

												// Check for 'x' keypress
												listenKey();
												
												return false;
											}
	
	imgPreload.src = objLink.getAttribute('href');

}





//
// hideLightbox()
//
function hideLightbox()
{
	var objDDL	= document.getElementById('criterio');
	
	if (objDDL) objDDL.style.display = 'inline';
	
	// 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 	= 1000;
 	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','loading_Image');
		objLoadingImageLink.appendChild(objLoadingImage);
		//objOverlay.appendChild(objLoadingImage);
		
		var objMes = document.createElement("div");
		objMes.setAttribute('id','lightboxMes');
		objMes.innerHTML = 'Caricamento immagine in corso...';
		objOverlay.appendChild(objMes);

		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 = 1100;
	objLightbox.onmouseover	= function() 	{ 	document.getElementById("nextButton").style.visibility = "visible"; 
															document.getElementById("prevButton").style.visibility = "visible";
														}
	objLightbox.onmouseout	= function() 	{	document.getElementById("nextButton").style.visibility = "hidden";  
															document.getElementById("prevButton").style.visibility = "hidden";
														}
	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);
	var objLink = objLightbox;

	// preload and create button image
	var imgPreloadCloseButton	= new Image();
	var imgPreloadPrevButton	= new Image();
	var imgPreloadNextButton	= new Image();

	// if close button image found, 
	imgPreloadCloseButton.onload = function(){

		var objCloseButton = document.createElement("img");
		objCloseButton.src = closeButton;
		objCloseButton.setAttribute('id','closeButton');
		objCloseButton.onclick = function () {hideLightbox(); return false;}
		objLink.appendChild(objCloseButton);

		return false;
	}
	
	// if prev button image found, 
	imgPreloadPrevButton.onload = function(){

		var objPrevButton = document.createElement("img");
		objPrevButton.src = prevButton;
		objPrevButton.setAttribute('id','prevButton');
		objPrevButton.style.visibility = "hidden"
		objLink.appendChild(objPrevButton);

		return false;
	}
	
	// if next button image found, 
	imgPreloadNextButton.onload = function() {

		var objNextButton = document.createElement("img");
		objNextButton.src = nextButton;
		objNextButton.setAttribute('id','nextButton');
		objNextButton.style.visibility = "hidden"
		objLink.appendChild(objNextButton);

		return false;
	}

	imgPreloadCloseButton.src	= closeButton;
	imgPreloadPrevButton.src	= prevButton;
	imgPreloadNextButton.src	= nextButton;

	// 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 date/autors (index)
	var objIndex = document.createElement("div");
	objIndex.setAttribute('id','lightboxIndex');
	objIndex.style.display = 'none';
	objLightboxDetails.appendChild(objIndex);
	
	// 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