(function($){
	
	
	$.apeng={
		
		mouseenter:function(){
			
			$(this).siblings().css({"opacity":.5})
			
		},
		mouseleave:function(){
			
			
			$(this).siblings().css({"opacity":1})
			
		},
		init:function(){
			
			
			$(".banners div,friendlink .row div,.row.hover div").on("mouseenter",$.apeng.mouseenter);
			$(".banners div,friendlink .row div,.row.hover div").on("mouseleave",$.apeng.mouseleave)
			
		}
		
		
	};
	$(function(){
		
		$.apeng.init();
		
	})
	
	
	function lazy(classname){
		this.classname = classname;
		// 
		lazy.prototype.isvisible = function ($node) {
			var scrolltop = $(window).scrolltop();  // 获取滚动条滚动高度
			var windowheight = $(window).height();  // 获取视窗高度
			var offsettop = $node.offset().top;      // 获取元素相对整个文档的高度
			if (offsettop < scrolltop + windowheight && offsettop > scrolltop) {
				return true;
			}
			return false;
		};
		lazy.prototype.init = function() {
			this._self = this;
			// 
			$(this.classname).attr("sign", "false");
			$(window).scroll(this.onscroll.bind(this));	//强制指定this
			this.onscroll();
		};
		lazy.prototype.onscroll = function() {
			//  这里this指向实例
			var that = this;
			$(this.classname).each(function () { 	// 对元素使用isvisible()检测
				// 这里this指向img dom元素
				if (that.isvisible($(this)) && $(this).attr("sign") === "false") {
					$(this).attr("sign", "true");
					$(this).attr('src', $(this).attr('data-src'));
				}
			})
		}

	}
	
	jquery.extend({
		'lazy': function(arg1) {
			return new lazy(arg1);
		}
	})

	
	
	
	
	
	
})(jquery)