/*
 * Lazy Load - jQuery plugin for lazy loading images
 *
 * Copyright (c) 2007-2009 Mika Tuupola
 *
 * Licensed under the MIT license:
 *   http://www.opensource.org/licenses/mit-license.php
 *
 * Project home:
 *   http://www.appelsiini.net/projects/lazyload
 *
 * Version:  1.5.0
 *
 */
(function($) {

	$.fn.lazyload = function(options) {
		var settings = {
			threshold: 0,
			failurelimit: 0,
			event: "scroll",
			effect: "show",
			container: window
		};
				
		if(options) {
			$.extend(settings, options);
		}

		/* Fire one scroll event per scroll. Not one scroll event per image. */
		var elements = this;
		if ("scroll" == settings.event) {
			$(settings.container).bind("scroll", function(event) {
				
				var counter = 0;
				elements.each(function() {
					if ($.abovethetop(this, settings) ||
						$.leftofbegin(this, settings)) {
							/* Nothing. */
					} else if (!$.belowthefold(this, settings) &&
						!$.rightoffold(this, settings)) {
							$(this).trigger("appear");
					} else {
						if (counter++ > settings.failurelimit) {
							return false;
						}
					}
				});
				/* Remove image from array so it is not looped next time. */
				var temp = $.grep(elements, function(element) {
					return !element.loaded;
				});
				elements = $(temp);
			});
		}
		
		this.each(function() {
			var self = this;
			
			/* Save original only if it is not defined in HTML. */
			if (undefined == $(self).attr("original")) {
				$(self).attr("original", $(self).attr("src"));	 
			}

			if ("scroll" != settings.event || 
					undefined == $(self).attr("src") || 
					settings.placeholder == $(self).attr("src") || 
					($.abovethetop(self, settings) ||
					 $.leftofbegin(self, settings) || 
					 $.belowthefold(self, settings) || 
					 $.rightoffold(self, settings) )) {
						
				if (settings.placeholder) {
					$(self).attr("src", settings.placeholder);	  
				} else {
					$(self).removeAttr("src");
				}
				self.loaded = false;
			} else {
				self.loaded = true;
			}
			
			/* When appear is triggered load original image. */
			$(self).one("appear", function() {
				if (!this.loaded) {
					$("<img />")
						.bind("load", function() {
							$(self)
								.hide()
								.attr("src", $(self).attr("original"))
								[settings.effect](settings.effectspeed);
							self.loaded = true;
						})
						.attr("src", $(self).attr("original")).removeAttr('original');
				};
			});

			/* When wanted event is triggered load original image */
			/* by triggering appear.							  */
			if ("scroll" != settings.event) {
				$(self).bind(settings.event, function(event) {
					if (!self.loaded) {
						$(self).trigger("appear");
					}
				});
			}
		});
		
		/* Force initial check if images should appear. */
		$(settings.container).trigger(settings.event);
		
		return this;

	};

	/* Convenience methods in jQuery namespace.		   */
	/* Use as  $.belowthefold(element, {threshold: 100, container: window}) */

	$.belowthefold = function(element, settings) {
		if (settings.container === undefined || settings.container === window) {
			var fold = $(window).height() + $(window).scrollTop();
		} else {
			var fold = $(settings.container).offset().top + $(settings.container).height();
		}
		return fold <= $(element).offset().top - settings.threshold;
	};
	
	$.rightoffold = function(element, settings) {
		if (settings.container === undefined || settings.container === window) {
			var fold = $(window).width() + $(window).scrollLeft();
		} else {
			var fold = $(settings.container).offset().left + $(settings.container).width();
		}
		return fold <= $(element).offset().left - settings.threshold;
	};
		
	$.abovethetop = function(element, settings) {
		if (settings.container === undefined || settings.container === window) {
			var fold = $(window).scrollTop();
		} else {
			var fold = $(settings.container).offset().top;
		}
		return fold >= $(element).offset().top + settings.threshold  + $(element).height();
	};
	
	$.leftofbegin = function(element, settings) {
		if (settings.container === undefined || settings.container === window) {
			var fold = $(window).scrollLeft();
		} else {
			var fold = $(settings.container).offset().left;
		}
		return fold >= $(element).offset().left + settings.threshold + $(element).width();
	};
	/* Custom selectors for your convenience.   */
	/* Use as $("img:below-the-fold").something() */

	$.extend($.expr[':'], {
		"below-the-fold": "$.belowthefold(a, {threshold: 0, container: window})",
		"above-the-fold": "!$.belowthefold(a, {threshold: 0, container: window})",
		"right-of-fold": "$.rightoffold(a, {threshold: 0, container: window})",
		"left-of-fold": "!$.rightoffold(a, {threshold: 0, container: window})"
	});
	
})(jQuery);

$(document).ready(function() {
	$("img").lazyload({
		placeholder: "/massramverk/i/placeholder.png",
		threshold: 4,
		failurelimit: 5
	});
});