/*

 * 	Easy Zoom 1.0 - jQuery plugin

 *	written by Alen Grakalic	

 *	http://cssglobe.com/post/9711/jquery-plugin-easy-image-zoom

 *

 *	Copyright (c) 2011 Alen Grakalic (http://cssglobe.com)

 *	Dual licensed under the MIT (MIT-LICENSE.txt)

 *	and GPL (GPL-LICENSE.txt) licenses.

 *

 *	Built for jQuery library

 *	http://jquery.com

 *

 */

 

 /*

 

 Required markup sample

 

 <a href="large.jpg"><img src="small.jpg" alt=""></a>

 

 */

 

(function($) {

		  

	$.fn.easyZoom = function(options){



		var defaults = {	

			id: 'easy_zoom',

			parent: 'body',

			append: true,

			preload: 'Cargando...',

			error: 'No es posible cargar la imagen.'

		}; 

		

		var obj;

		var img = new Image();

		var loaded = false;

		var found = true;

		var timeout;

		var w1,w2,h1,h2,rw,rh;

		var over = false;

		

		var options = $.extend(defaults, options);  

		

		this.each(function(){ 

				

			obj = this;	

			// works only for anchors

			var tagName = this.tagName.toLowerCase();

			if(tagName == 'a'){			   

				

				var href = $(this).attr('href');			

				img.src = href + '?' + (new Date()).getTime() + ' =' + (new Date()).getTime();

				$(img).error(function(){ found = false; })												

				img.onload = function(){ 									

					loaded = true;	

					img.onload=function(){};

				};	

				

				$(this)

					.css('cursor','crosshair')

					.click(function(e){ e.preventDefault(); })

					.mouseover(function(e){ start(e); })

					.mouseout(function(){ hide(); })		

					.mousemove(function(e){ move(e); })			

			};

			

		});

		

		function start(e){

			hide();			

			var zoom = $('<div id="'+ options.id +'">'+ options.preload +'</div>');

			if(options.append) { zoom.appendTo(options.parent) } else { zoom.prependTo(options.parent) };

			if(!found){

				error();

			} else {

				if(loaded){

					show(e);

				} else {

					loop(e);

				};				

			};			

		};

		

		function loop(e){

			if(loaded){

				show(e);

				clearTimeout(timeout);

			} else {

				timeout = setTimeout(function(){loop(e)},200);

			};

		};

		

		function show(e){

			over = true;

			$(img).css({'position':'absolute','top':'0','left':'0'});

			$('#'+ options.id).html('').append(img);			

			w1 = $('img', obj).width();

			h1 = $('img', obj).height();

			w2 = $('#'+ options.id).width();

			h2 = $('#'+ options.id).height();

			w3 = $(img).width();

			h3 = $(img).height();	

			w4 = $(img).width() - w2;

			h4 = $(img).height() - h2;	

			rw = w4/w1;

			rh = h4/h1;

			move(e);

		};

		

		function hide(){

			over = false;

			$('#'+ options.id).remove();

		};

		

		function error(){

			$('#'+ options.id).html(options.error);

		};

		

		function move(e){

			if(over){

				// target image movement

				var p = $('img',obj).offset();

				var pl = e.pageX - p.left;

				var pt = e.pageY - p.top;	

				var xl = pl*rw;

				var xt = pt*rh;

				xl = (xl>w4) ? w4 : xl;

				xt = (xt>h4) ? h4 : xt;	

				$('#'+ options.id + ' img').css({'left':xl*(-1),'top':xt*(-1)});

			};

		};

	

	};



})(jQuery);