// -------------------------------------------------------------------
// Image Thumbnail Viewer Script- By Dynamic Drive, available at: http://www.dynamicdrive.com
// Last updated: July 7th, 2008- Fixed enlarged image not showing in IE sometimes
// -------------------------------------------------------------------

var thumbnailviewer={
	
	enableTitle: false, //Should "title" attribute of link be used as description?
	enableAnimation: true, //Enable fading animation?
	definefooter: '<div class="footerbar">CLOSE X</div>', //Define HTML for footer interface
	
	//Define HTML for "loading" div
	defineLoading: '<img src="http://www.hiddengambia.com/adventure_holidays/images/loading.gif" /> Loading Image...', 
	
	scrollbarwidth: 16,
	
	opacitystring: 'filter:progid:DXImageTransform.Microsoft.alpha(opacity=10); -moz-opacity: 0.1; opacity: 0.1',
	
	//Array to hold links with rel="thumbnail"
	targetlinks:[], 
	
	//Write out HTML for Image Thumbnail Viewer plus loading div
	createthumbBox:function(){	
		document.write('<div id="thumbBox" onClick="thumbnailviewer.closeit()">'+this.definefooter+'<div id="thumbImage"></div></div>')
		document.write('<div id="thumbLoading">'+this.defineLoading+'</div>')
		this.thumbBox=document.getElementById("thumbBox")
		this.thumbImage=document.getElementById("thumbImage") //Reference div that holds the shown image
		this.thumbLoading=document.getElementById("thumbLoading") //Reference "loading" div that will be shown while image is fetched
		this.standardbody=(document.compatMode=="CSS1Compat")? document.documentElement : document.body //create reference to common "body" across doctypes
	},
	
	//Centers a div element on the page
	centerDiv:function(divobj){ 
		var ie=document.all && !window.opera
		var dom=document.getElementById
		var scroll_top=(ie)? this.standardbody.scrollTop : window.pageYOffset
		var scroll_left=(ie)? this.standardbody.scrollLeft : window.pageXOffset
		var docwidth=(ie)? this.standardbody.clientWidth : window.innerWidth-this.scrollbarwidth
		var docheight=(ie)? this.standardbody.clientHeight: window.innerHeight
		var docheightcomplete=(this.standardbody.offsetHeight>this.standardbody.scrollHeight)? this.standardbody.offsetHeight : this.standardbody.scrollHeight //Full scroll height of document
		var objwidth=divobj.offsetWidth //width of div element
		var objheight=divobj.offsetHeight //height of div element
		var topposition=(docheight>objheight)? scroll_top+docheight/2-objheight/2+"px" : scroll_top+10+"px" //Vertical position of div element: Either centered, or if element height larger than viewpoint height, 10px from top of viewpoint
		//var topposition=scroll_top+150+"px";
		divobj.style.left=docwidth/2-objwidth/2+"px" //Center div element horizontally
		//divobj.style.left=((docwidth-760)/2)+160+"px"
		divobj.style.top=Math.floor(parseInt(topposition))+"px"
		divobj.style.visibility="visible"
	},
	
	//Show ThumbBox div
	showthumbBox:function(){ 
		thumbnailviewer.thumbLoading.style.visibility="hidden" //Hide "loading" div
		this.centerDiv(this.thumbBox)
		if (this.enableAnimation){ //If fading animation enabled
			this.currentopacity=0.1 //Starting opacity value
			this.opacitytimer=setInterval("thumbnailviewer.opacityanimation()", 20)
		}
		grayOut(true)
	},
	
	//Load image function that gets attached to each link on the page with rel="thumbnail"
	loadimage:function(link){ 
		//if thumbox is visible on the page already
		if (this.thumbBox.style.visibility=="visible") 
			this.closeit() //Hide it first (not doing so causes triggers some positioning bug in Firefox
			var imageHTML='<img src="'+link.getAttribute("href")+'" style="'+this.opacitystring+'" />' //Construct HTML for shown image
			if (this.enableTitle && link.getAttribute("title")) //Use title attr of the link as description?
			imageHTML+='<br />'+link.getAttribute("title")
			this.centerDiv(this.thumbLoading) //Center and display "loading" div while we set up the image to be shown
			this.thumbImage.innerHTML=imageHTML //Populate thumbImage div with shown image's HTML (while still hidden)
			this.featureImage=this.thumbImage.getElementsByTagName("img")[0] //Reference shown image itself
			
			if (this.featureImage.complete) {
				thumbnailviewer.showthumbBox()
			} else {
				this.featureImage.onload=function(){ //When target image has completely loaded
				thumbnailviewer.showthumbBox() //Display "thumbbox" div to the world!
			}
		}
		//Target IE5.0 browsers only. Address IE image cache not firing onload bug: panoramio.com/blog/onload-event/
		if (document.all && !window.createPopup) 
			this.featureImage.src=link.getAttribute("href")
			this.featureImage.onerror=function(){ //If an error has occurred while loading the image to show
			thumbnailviewer.thumbLoading.style.visibility="hidden" //Hide "loading" div, game over
		}
	},
	
	//Sets the opacity of "thumbimage" div per the passed in value setting (0 to 1 and in between)
	setimgopacity:function(value){ 
		var targetobject=this.featureImage
		if (targetobject.filters && targetobject.filters[0]){ //IE syntax
		if (typeof targetobject.filters[0].opacity=="number") //IE6
		targetobject.filters[0].opacity=value*100
		else //IE 5.5
		targetobject.style.filter="alpha(opacity="+value*100+")"
		}
		else if (typeof targetobject.style.MozOpacity!="undefined") //Old Mozilla syntax
		targetobject.style.MozOpacity=value
		else if (typeof targetobject.style.opacity!="undefined") //Standard opacity syntax
		targetobject.style.opacity=value
		else //Non of the above, stop opacity animation
		this.stopanimation()
	},
	
	//Gradually increase opacity function
	opacityanimation:function(){ 
		this.setimgopacity(this.currentopacity)
		this.currentopacity+=0.1
		if (this.currentopacity>1)
		this.stopanimation()
	},
	
	stopanimation:function(){
		if (typeof this.opacitytimer!="undefined")
		clearInterval(this.opacitytimer)
	},
	
	//Close "thumbbox" div function
	closeit:function(){ 
		this.stopanimation()
		this.thumbBox.style.visibility="hidden"
		this.thumbImage.innerHTML=""
		this.thumbBox.style.left="-2000px"
		this.thumbBox.style.top="-2000px"
		grayOut(false)
	},
	
	//Clean up routine on page unload
	cleanup:function(){ 
		this.thumbLoading=null
		if (this.featureImage) this.featureImage.onload=null
		this.featureImage=null
		this.thumbImage=null
		for (var i=0; i<this.targetlinks.length; i++)
		this.targetlinks[i].onclick=null
		this.thumbBox=null
	},
	
	//Assign a function to execute to an event handler (ie: onunload)
	dotask:function(target, functionref, tasktype){ 
		var tasktype=(window.addEventListener)? tasktype : "on"+tasktype
		if (target.addEventListener)
		target.addEventListener(tasktype, functionref, false)
		else if (target.attachEvent)
		target.attachEvent(tasktype, functionref)
	},
	
	//Initialize thumbnail viewer script by scanning page and attaching appropriate function to links with rel="thumbnail"
	init:function(){ 
		if (!this.enableAnimation)
		this.opacitystring=""
		var pagelinks=document.getElementsByTagName("a")
		for (var i=0; i<pagelinks.length; i++){ //BEGIN FOR LOOP
		if (pagelinks[i].getAttribute("rel") && pagelinks[i].getAttribute("rel")=="thumbnail"){ //Begin if statement
		pagelinks[i].onclick=function(){
		thumbnailviewer.stopanimation() //Stop any currently running fade animation on "thumbbox" div before proceeding
		thumbnailviewer.loadimage(this) //Load image
		return false
		}
		this.targetlinks[this.targetlinks.length]=pagelinks[i] //store reference to target link
		} //end if statement
		} //END FOR LOOP
		//Reposition "thumbbox" div when page is resized
		this.dotask(window, function(){if (thumbnailviewer.thumbBox.style.visibility=="visible") thumbnailviewer.centerDiv(thumbnailviewer.thumbBox)}, "resize")
	}
}

function grayOut(vis, options) {
// Pass true to gray out screen, false to ungray
// options are optional. This is a JSON object with the following (optional) properties
// opacity:0-100 // Lower number = less grayout higher = more of a blackout
// zindex: # // HTML elements with a higher zindex appear on top of the gray
// bgcolor: (#xxxxxx) // Standard RGB Hex color code
// grayOut(true, {'zindex':'50', 'bgcolor':'#0000FF', 'opacity':'70'});
// Because options is JSON opacity/zindex/bgcolor are all optional and can appear
// in any order. Pass only the properties you need to set.
var options = options || {};
var zindex = options.zindex || 50;
var opacity = options.opacity || 50;
var opaque = (opacity / 100);
var bgcolor = options.bgcolor || '#000000';
var dark=document.getElementById('darkenScreenObject');
if (!dark) {
// The dark layer doesn't exist, it's never been created. So we'll
// create it here and apply some basic styles.
// If you are getting errors in IE see: http://support.microsoft.com/default.aspx/kb/92
var tbody = document.getElementsByTagName("body")[0];
var tnode = document.createElement('div'); // Create the layer.
tnode.style.position='absolute'; // Position absolutely
tnode.style.top='0px'; // In the top
tnode.style.left='0px'; // Left corner of the page
tnode.style.overflow='hidden'; // Try to avoid making scroll bars
tnode.style.display='none'; // Start out Hidden
tnode.id='darkenScreenObject'; // Name it so we can find it later
tbody.appendChild(tnode); // Add it to the web page
dark=document.getElementById('darkenScreenObject'); // Get the object.
}
if (vis) {
// Calculate the page width and height
if( document.body && ( document.body.scrollWidth || document.body.scrollHeight ) ) {
var pageWidth = document.body.scrollWidth+'px';
var pageHeight = document.body.scrollHeight+'px';
} else if( document.body.offsetWidth ) {
var pageWidth = document.body.offsetWidth+'px';
var pageHeight = document.body.offsetHeight+'px';
} else {
var pageWidth='100%';
var pageHeight='100%';
}
//set the shader to cover the entire page and make it visible.
dark.style.opacity=opaque;
dark.style.MozOpacity=opaque;
dark.style.filter='alpha(opacity='+opacity+')';
dark.style.zIndex=zindex;
dark.style.backgroundColor=bgcolor;
dark.style.width= pageWidth;
dark.style.height= pageHeight;
dark.style.display='block';
} else {
dark.style.display='none';
}
}

thumbnailviewer.createthumbBox() //Output HTML for the image thumbnail viewer
thumbnailviewer.dotask(window, function(){thumbnailviewer.init()}, "load") //Initialize script on page load
thumbnailviewer.dotask(window, function(){thumbnailviewer.cleanup()}, "unload")