/*
 *
 * Copyright (c) 2010 C. F., Wong (<a href="http://cloudgen.w0ng.hk">Cloudgen Examplet Store</a>)
 * Licensed under the MIT License:
 * http://www.opensource.org/licenses/mit-license.php
 *
 */
(function($){
	function parseCSS(obj,css){
		var r=0;
		obj.css(css).replace(/\b(\d+)px\b/,function(s,t){r=parseInt(t)});
		return r;
	}
	function Lens(target,width,height,callBack){
		if(target){
			var w=width||100,h=height||100;
			this.callBack=(typeof callBack=="function")?callBack:function(){};
			this.target=$(target);
			this.disabled=false;
			this.callBack=callBack||function(){};
			this.anchor=this.target.wrap(document.createElement("a")).closest("a").data("Lens",this)
				.unbind("mouseover").unbind("mouseout").unbind("mousemove")
				.hover(function(e){
				$(this).data("Lens").show(e)
			},function(){
				$(this).data("Lens").hide()
			}).mousemove(function(e){
				$(this).data("Lens").show(e)
			});
			var jNode=$('<div id="jquery-lens" style="position:absolute;z-index:900;'
				+'cursor:pointer;"></div>').css({width:w,height:h}).appendTo(this.anchor).hide();
			this.jNode=jNode.css({top:this.target.offset().top,left:this.target.offset().left});
			this.offset={top:this.target.offset().top+parseCSS(this.target,'borderTopWidth'),left:this.target.offset().left+parseCSS(this.target,'borderLeftWidth'),width:w,height:h};
			this.adjustedTarget={top:this.target.offset().top+parseCSS(this.target,'borderTopWidth'),left:this.target.offset().left+parseCSS(this.target,'borderLeftWidth')}
			this.target.data("Lens",this);
		}
	}
	Lens.prototype.remove=function(){
		this.jNode.remove();
	};
	Lens.prototype.show=function(e){
		if(!this.disabled){
			this.mouseX=e.pageX;
			this.mouseY=e.pageY;
			this.offset.left=parseInt(this.mouseX-this.offset.width/2);
			this.offset.left=(this.offset.left<this.adjustedTarget.left)?this.adjustedTarget.left:this.offset.left;
			this.offset.left=(this.offset.left>this.adjustedTarget.left+this.target.width()-this.offset.width)
				?this.adjustedTarget.left+this.target.width()-this.offset.width:this.offset.left;
			this.offset.top=parseInt(this.mouseY-this.offset.height/2);
			this.offset.top=(this.offset.top<this.adjustedTarget.top)?this.adjustedTarget.top:this.offset.top;
			this.offset.top=(this.offset.top>this.adjustedTarget.top+this.target.height()-this.offset.height)
				?this.adjustedTarget.top+this.target.height()-this.offset.height:this.offset.top;
			this.jNode.css({top:this.offset.top,left:this.offset.left});
			this.relative={top:parseInt(this.offset.top-this.adjustedTarget.top),left:parseInt(this.offset.left-this.adjustedTarget.left)};
			this.jNode.show();
			if(typeof this.callBack=="function") this.callBack.apply(this.target);
		}
	};
	Lens.prototype.hide=function(){
		this.jNode.hide();
	};
	Lens.prototype.disable=function(){
		this.disabled=true;
	};
	Lens.prototype.enable=function(){
		this.disabled=false;
	};
	$.fn.addLens=function(width,height,callBack){
		var w,h,c;
		if(typeof width=="function") c=width;
		else c=(typeof callBack=="function")?callBack:function(){};
		w=(typeof width!="number") ?100:width;
		h=(typeof height!="number") ?100:height;
		new Lens(this,w,h,c);
	};
	$.fn.showLens=function(){
		this.data("Lens").show();
	};
	$.fn.hideLens=function(){
		this.data("Lens").hide();
	};
	$.fn.removeLens=function(){
		this.data("Lens").remove();
	};
})(jQuery);