///////////////////////////////////
//
//	THUMBS
//
///////////////////////////////////

var thumbnailviewer={

	enableTitle: true,

	enableAnimation: true,

	definefooter: '<div class="footerbar">ZAVŘÍT</div>',

	defineLoading: '<img src="images/loading.gif" width="16" height="16" alt="" /> Nahrávám obrázek',

	scrollbarwidth: 16,

	opacitystring: 'filter:progid:DXImageTransform.Microsoft.alpha(opacity=10); -moz-opacity: 0.1; opacity: 0.1',

	targetlinks:[],

	createthumbBox:function()
	{
		document.write('<div id="thumbBox" onClick="thumbnailviewer.closeit()"><div id="thumbImage"></div>'+this.definefooter+'</div>');

		document.write('<div id="thumbLoading">'+this.defineLoading+'</div>');

		this.thumbBox=document.getElementById("thumbBox");

		this.thumbImage=document.getElementById("thumbImage");

		this.thumbLoading=document.getElementById("thumbLoading");

		this.standardbody=(document.compatMode=="CSS1Compat")? document.documentElement : document.body;
	},

	centerDiv:function(divobj)
	{
		var ie=document.all && !window.opera;

		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;

		if (document.getElementById("thumbsimage"))
		{
			var w=document.getElementById("thumbsimage").offsetWidth;

			var h=document.getElementById("thumbsimage").offsetHeight;

			var wmax=docwidth-40;

			var hmax=docheight-60;

			if (w>wmax) {h=parseInt(wmax/w*h);w=wmax;}

			if (h>hmax) {w=parseInt(hmax/h*w);h=hmax;}

			document.getElementById("thumbsimage").style.width=w+"px";

			document.getElementById("thumbsimage").style.height=h+"px";
		}

		var objwidth=divobj.offsetWidth;

		var objheight=divobj.offsetHeight;

		var topposition=(docheight>objheight)? scroll_top+docheight/2-objheight/2+"px" : scroll_top+10+"px";

		divobj.style.left=docwidth/2-objwidth/2+"px";

		divobj.style.top=Math.floor(parseInt(topposition))+"px";

		divobj.style.visibility="visible";
	},

	showthumbBox:function()
	{
		thumbnailviewer.thumbLoading.style.visibility="hidden";

		this.centerDiv(this.thumbBox);

		if (this.enableAnimation)
		{
			this.currentopacity=0.1;

			this.opacitytimer=setInterval("thumbnailviewer.opacityanimation()",20);
		}
	},

	loadimage:function(link)
	{
		if (this.thumbBox.style.visibility=="visible")
		{
			this.closeit();
		}

		var photo_title=link.getAttribute("title");		

		if (link.getAttribute("title")=='Zvětšit obrázek')
		{
			var photo_title='';
		}

		var imageHTML='<img src="'+link.getAttribute("href")+'" style="'+this.opacitystring+'" id="thumbsimage" alt="'+photo_title+'" />';

		this.centerDiv(this.thumbLoading);

		this.thumbImage.innerHTML=imageHTML;

		this.featureImage=this.thumbImage.getElementsByTagName("img")[0];

		if (this.featureImage.complete)
		{
			thumbnailviewer.showthumbBox();
		}
		else
		{
			this.featureImage.onload=function()
			{
				thumbnailviewer.showthumbBox();
			}
		}

		if (document.all && !window.createPopup)
		{
			this.featureImage.src=link.getAttribute("href");
		}

		this.featureImage.onerror=function()
		{
			thumbnailviewer.thumbLoading.style.visibility="hidden";
		}
	},

	setimgopacity:function(value)
	{
		var targetobject=this.featureImage;

		if (targetobject.filters && targetobject.filters[0])
		{
			if (typeof targetobject.filters[0].opacity=="number")
			targetobject.filters[0].opacity=value*100;
			else
			targetobject.style.filter="alpha(opacity="+value*100+")";
		}
		else if (typeof targetobject.style.MozOpacity!="undefined")
		targetobject.style.MozOpacity=value;
		else if (typeof targetobject.style.opacity!="undefined")
		targetobject.style.opacity=value;
		else
		this.stopanimation();
	},

	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);
		}
	},

	closeit:function()
	{
		this.stopanimation();

		this.thumbBox.style.visibility="hidden";

		this.thumbImage.innerHTML="";

		this.thumbBox.style.left="-2000px";

		this.thumbBox.style.top="-2000px";
	},

	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;
	},

	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);
	},

	init:function()
	{
		if (!this.enableAnimation)
		{
			this.opacitystring="";
		}

		var pagelinks=document.getElementsByTagName("a");
		for (var i=0; i<pagelinks.length; i++)
		{
			if (pagelinks[i].getAttribute("rel") && pagelinks[i].getAttribute("rel")=="thumbnail")
			{
				pagelinks[i].onclick=function()
				{
					thumbnailviewer.stopanimation();
					thumbnailviewer.loadimage(this);
					return false;
				}

				this.targetlinks[this.targetlinks.length]=pagelinks[i];
			}
		}

		this.dotask(window, function(){if (thumbnailviewer.thumbBox.style.visibility=="visible") thumbnailviewer.centerDiv(thumbnailviewer.thumbBox)}, "resize")
	}
}

thumbnailviewer.createthumbBox();

thumbnailviewer.dotask(window, function(){thumbnailviewer.init()}, "load");

thumbnailviewer.dotask(window, function(){thumbnailviewer.cleanup()}, "unload");