/**************************************************************

	Script		: Overlay
	Version		: 1.2
	Authors		: Samuel birch
	Desc		: Covers the window with a semi-transparent layer.
	Licence		: Open Source MIT Licence

**************************************************************/

var Overlay = new Class({
	
	getOptions: function(){
		return {
			colour: '#000',
			opacity: 0.7,
//			zIndex: 1,
			container: document.body,
			onClick: Class.empty
		};
	},

	initialize: function(options){
		this.setOptions(this.getOptions(), options);
		this.options.container = $(this.options.container);
		this.container = new Element('div').setProperty('id', 'OverlayContainer').setStyles({
			position: 'absolute',
			left: '0px',
			top: '0px',
			width: '100%',
			height: '100%',
//			zIndex: this.options.zIndex,
			backgroundColor: this.options.colour
		}).injectInside(this.options.container);
		
		this.fade = new Fx.Style(this.container, 'opacity').set(0);
		
//		this.position();
		
		window.addEvent('resize', this.position.bind(this));

	},
	
	position: 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;
		}
//			var h = window.getScrollHeight()+'px';
		this.container.setStyles({top: '0px',left: '0px', height: pageHeight, width: pageWidth});

	},
	
	show: function(){
		this.position();
		this.fade.start(0,this.options.opacity);
		this.position();		
	},
	
	hide: function(){
		this.position();
		this.fade.start(this.options.opacity,0);
		this.container.setStyles({top: '0px',left: '0px', height: '0px', width: '0px'});
	}
	
});
Overlay.implement(new Options);

/*************************************************************/