Web/JS/lazyload.js

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//图片延迟加载插件
(function($){
	$.fn.lazyload=function(options){
		var settings = {
			threshold:0,
			failurelimit:0,
			event:"scroll",
			effect:"show",
			container:window
		};
		if(options){
			$.extend(settings,options);
		}
	var elements=this;
	
	if("scroll"==settings.event){
		$(settings.container).bind("scroll", function(event){
			var counter=0;
			elements.each(function(){
				if($.abovethetop(this,settings)||$.leftofbegin(this,settings))
				{}else if(!$.belowthefold(this,settings)&&!$.rightoffold(this,settings)){
					$(this).trigger("appear");
				}else{
					if(counter++ > settings.failurelimit){
						return false;
					}
				}
			});
			var temp = $.grep(elements,function(element){
				return !element.loaded;
			});
			elements = $(temp);
		});
	}

	this.each(function(){
	
		var self=this;
		
		if(undefined==$(self).attr("original")){
			$(self).attr("original", $(self).attr("src"));
		}if("scroll" != settings.event||undefined == $(self).attr("src")||"" == $(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;
		}
		
		$(self).one("appear", function(){
			if(!this.loaded || 1 == 1){
				$("<img />").bind("load", function(){
					$(self).hide().attr("src", $(self).attr("original"))[settings.effect](settings.effectspeed);
					self.loaded=true;
				}).attr("src", $(self).attr("original"));
			};
		});
		
		if("scroll"!=settings.event){