/**
 * NVS_OVERLAY
 * 
 * @author			Sebastiaan Smid <sebastiaan@netvlies.nl>
 * 
 * Optional parameters:
 * @category			jQuery Plugin
 * @package			Netvlies Overlay
 * @version			1.0
 *
 */

(function($) {
 
	$.nvsOverlay= { 
	
		/**
		 * Show the overlay with default settings or the given params
		 * Also binds window resizing to overlayResize
		 * @param 	Object		background string (cssProperty), speed int (milliseconds), transparancy decimal (between 0 and 1), callback function
		 */

		show : function (options) { 
		// default settings	
			var defaults = {
				background: 'black',
				speed: 1500,
				height: this.overlayHeight(),
				transparancy: '0.5',
				callback: false
			};	
			options = $.extend(defaults, options);
		
		//hide elements that show through the overlay in IE 6
			if($.browser.msie && $.browser.version <= 6) {
				$('embed, object, select').css({ 'visibility' : 'hidden' });
			} 
			
		//add overlay to the DOM
			$('<div></div>').attr({
							id: 'nvs_overlay' 
							})
						.css({
							position: 'absolute',
							top: 0,
							left: 0,
							height: options.height,
							width: '100%',
							zIndex: '9999',
							opacity: '0',
							background: options.background
							})
						.appendTo('body')
						.fadeTo(options.speed, options.transparancy, options.callback);
	
		// bind resize function on window resize event, this will reposition the overlay when window resizes or scrolls
			$(window).bind('resize', this.overlayResize);		
		},
		
		/**
		* Hides the overlay and unbinds window resize method
		*/
		hide :	function () { 
			if($('#nvs_overlay')){
				// first fade and remove on callback
				$('#nvs_overlay').fadeTo('slow', 0, function () { 
					$('#nvs_overlay').remove();
					$('embed, object, select').css({ 'visibility' : 'visible' });
				});
			}
			$(window).unbind('resize', this.overlayResize);
		},
		
		/**
		* Resizes the overlay bound to resize event of the window DOM element
		*/
		overlayResize : function() {
			$('#nvs_overlay').css({ width: 0, height: 0 });
			oheight = $.nvsOverlay.overlayHeight();
			$('#nvs_overlay').css({	width: '100%', height: oheight });
		},
		
		/**
		 * Calculates the height of the overlay 
		 * @returns 	INT		Height of the window or document DOM element
		*/
		overlayHeight : function () {

			if($(document).height() > $(window).height()) {
				oHeight = $(document).height()
			} else {
				oHeight = $(window).height();	
			}
			
			return oHeight;
		}
		
	}
	
})(jQuery);