1 ‘use strict‘; 2 function RedEnvelope(options){ 3     if(this === window){ 4         return new RedEnvelope(options); 5     } 6     var defaults = { 7         imgWidth:60,//红包的宽度 8         position:‘absolute‘, 9         imgEnvSrc:‘../images/game/redEnv/redEnv.png‘,10         containerClass:‘.redEnv-contain‘11     };12     if(!options){13         options = defaults;14     }else{15         for (var option in defaults) {16             if (typeof options[option] === undefined) {17                 options[option] = defaults[option];18             }19         }20     }21     this.options = options;22     this.createEnv();23 }24 RedEnvelope.prototype.createEnv = function(){25     var imgEnv = document.createElement(‘img‘);26     imgEnv.src = http://www.mamicode.com/this.options.imgEnvSrc;27     imgEnv.style.width = this.options.imgWidth+‘px‘;28     this.evnPosition(imgEnv);29 }30 RedEnvelope.prototype.evnPosition = function(img){31     var containerWidth = $(this.options.containerClass).width();32     var containerHeight = window.screen.height;33     $(this.options.containerClass).prepend(img);34     //红包初始的位置35     img.style.position = this.options.position;36     var startTop = parseInt(Math.random()*10+(-10))37     var startLeft = parseInt(Math.random()*containerWidth);38     //移动的位置39     var moveLeft = parseInt(Math.random()*containerWidth+(-30));40     var t=parseInt(Math.random() * 1000+1200);41     this.evnAnimation({‘startLeft‘:startLeft, ‘startTop‘:startTop, ‘moveLeft‘:moveLeft,‘moveTop‘:containerHeight},t);42 }43 /*添加元素到主内容上*/44 RedEnvelope.prototype.evnAnimation =  function (posObject,time){45     $(this.options.containerClass).children(‘img:first‘).css({‘left‘:posObject.startLeft,‘top‘:posObject.startTop});46     $(this.options.containerClass).children(‘img:first‘).animate(47         {48             ‘left‘:posObject.startLeft-posObject.moveLeft,49             ‘top‘:posObject.moveTop50         },51         time,52         ‘linear‘,53         function(){54             $(this).remove();55         }56     );57