/**
* MyLightbox
*
* This libary is used to create a MyLightbox in a web application.  This library
* requires the Prototype 1.6 library and Script.aculo.us core, effects, and dragdrop
* libraries.  To use, add a div containing the content to be displayed anywhere on 
* the page.  To create the MyLightbox, add the following code:
*
*	var test;
*	
*	Event.observe(window, 'load', function () {
*		test = new MyLightbox('idOfMyDiv');
*	});
*	
*	Event.observe('MyLightboxLink', 'click', function () {
*		test.open();
*	});
*
*	Event.observe('closeLink', 'click', function () {
*		test.close();
*	});
*     
*/

var MyLightbox = Class.create({
	open : function () {
		this._centerWindow(this.container);
		this._fade('open', this.container);
	},
	
	close : function () {
		this._fade('close', this.container);
	},
	
	_fade : function fadeBg(userAction,whichDiv){
		if(userAction=='close'){
			new Effect.Opacity('bg_fade',
					   {duration:.5,
					    from:0.5,
					    to:0,
					    afterFinish:this._makeInvisible,
					    afterUpdate:this._hideLayer(whichDiv)});
		}else{
			new Effect.Opacity('bg_fade',
					   {duration:.5,
					    from:0,
					    to:0.5,
					    beforeUpdate:this._makeVisible,
					    afterFinish:this._showLayer(whichDiv)});
		}
	},
	
	_makeVisible : function makeVisible(){
		$("bg_fade").style.visibility="visible";
	},

	_makeInvisible : function makeInvisible(){
		$("bg_fade").style.visibility="hidden";
	},

	_showLayer : function showLayer(userAction){
		$(userAction).style.display="block";
	},
	
	_hideLayer : function hideLayer(userAction){
		$(userAction).style.display="none";
	},
	
	_centerWindow : function centerWindow(element) {
		var windowHeight = parseFloat($(element).getHeight())/2; 
		var windowWidth = parseFloat($(element).getWidth())/2;

		if(typeof window.innerHeight != 'undefined') {
			//alert(document.documentElement.scrollTop);
			$(element).style.top = Math.round(document.documentElement.scrollTop + ((window.innerHeight - $(element).getHeight()))/2)+'px';
			//$(element).style.top = Math.round(document.body.offsetTop + ((window.innerHeight - $(element).getHeight()))/2)+'px';
			$(element).style.left = Math.round(document.body.offsetLeft + ((window.innerWidth - $(element).getWidth()))/2)+'px';
		} else {
			//alert(document.documentElement.scrollTop);
			$(element).style.top = Math.round(document.documentElement.scrollTop + ((document.documentElement.offsetHeight - $(element).getHeight()))/2)+'px';
			$(element).style.left = Math.round(document.body.offsetLeft + ((document.documentElement.offsetWidth - $(element).getWidth()))/2)+'px';
		}
	},

    //
    //  getPageSize()
    //
    getPageSize: function() {
	        
	     var xScroll, yScroll;
		
		if (window.innerHeight && window.scrollMaxY) {	
			xScroll = window.innerWidth + window.scrollMaxX;
			yScroll = window.innerHeight + window.scrollMaxY;
		} else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
			xScroll = document.body.scrollWidth;
			yScroll = document.body.scrollHeight;
		} else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
			xScroll = document.body.offsetWidth;
			yScroll = document.body.offsetHeight;
		}
		
		var windowWidth, windowHeight;
		
		if (self.innerHeight) {	// all except Explorer
			if(document.documentElement.clientWidth){
				windowWidth = document.documentElement.clientWidth; 
			} else {
				windowWidth = self.innerWidth;
			}
			windowHeight = self.innerHeight;
		} else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
			windowWidth = document.documentElement.clientWidth;
			windowHeight = document.documentElement.clientHeight;
		} else if (document.body) { // other Explorers
			windowWidth = document.body.clientWidth;
			windowHeight = document.body.clientHeight;
		}	
		
		// for small pages with total height less then height of the viewport
		if(yScroll < windowHeight){
			pageHeight = windowHeight;
		} else { 
			pageHeight = yScroll;
		}
	
		// for small pages with total width less then width of the viewport
		if(xScroll < windowWidth){	
			pageWidth = xScroll;		
		} else {
			pageWidth = windowWidth;
		}

		return [pageWidth,pageHeight];
	},
	
	initialize : function(containerDiv) {
		this.container = containerDiv;
		if($('bg_fade') == null) {
			//var screen = new Element('div', {'id': 'bg_fade', 'onClick': 'calc_lbox.close();'});
			//document.body.appendChild(screen);
		}
		new Draggable(this.container);
		this._hideLayer(this.container);
	}
});