javascript事件模型框架-eventutil.js

 

var EventUtil = new Object;
/**//*
   此方法用来给特定对象添加事件，oTarget是指定对象,sEventType是事件类型，如click、keydown等，     fnHandler是事件回调函数
/*
EventUtil.addEventHandler = function (oTarget, sEventType, fnHandler) {
     //firefox情况下
     if (oTarget.addEventListener) {
         oTarget.addEventListener(sEventType, fnHandler, false);
     }
     //IE下
     else if (oTarget.attachEvent) {
         oTarget.attachEvent("on" + sEventType, fnHandler);
     }
     else {
         oTarget["on" + sEventType] = fnHandler;
     }
};
/*
   此方法用来移除特定对象的特定事件，oTarget是指定对象,sEventType是事件类型，如click、keydown等，fnHandler是事件回调函数
/*      
EventUtil.removeEventHandler = function (oTarget, sEventType, fnHandler) {
     if (oTarget.removeEventListener) {
         oTarget.removeEventListener(sEventType, fnHandler, false);
     } else if (oTarget.detachEvent) {
         oTarget.detachEvent("on" + sEventType, fnHandler);
     } else {
         oTarget["on" + sEventType] = null;
     }
};

/*
格式化事件，因为IE和其他浏览器下获取事件的方式不同并且事件的属性也不尽相同，通过此方法提供一个一致的事件
*/
EventUtil.formatEvent = function (oEvent) {
     //isIE和isWin引用到一个js文件，判断浏览器和操作系统类型
     if (isIE && isWin) {
         oEvent.charCode = (oEvent.type == "keypress") ? oEvent.keyCode : 0;
         //IE只支持冒泡，不支持捕获
         oEvent.eventPhase = 2;
         oEvent.isChar = (oEvent.charCode > 0);
         oEvent.pageX = oEvent.clientX + document.body.scrollLeft;
         oEvent.pageY = oEvent.clientY + document.body.scrollTop;
         //阻止事件的默认行为
         oEvent.preventDefault = function () {
             this.returnValue = false;
         };

          //将toElement,fromElement转化为标准的relatedTarget
         if (oEvent.type == "mouseout") {
             oEvent.relatedTarget = oEvent.toElement;
         } else if (oEvent.type == "mouseover") {
             oEvent.relatedTarget = oEvent.fromElement;
         }
         //取消冒泡     
         oEvent.stopPropagation = function () {
             this.cancelBubble = true;
         };

         oEvent.target = oEvent.srcElement;
         //添加事件发生时间属性，IE没有
         oEvent.time = (new Date).getTime();
     }
     return oEvent;
};

EventUtil.getEvent = function() {
     if (window.event) {
         //格式化IE的事件
         return this.formatEvent(window.event);
     } else {
         return EventUtil.getEvent.caller.arguments[0];
     }
};