跨浏览器的事件处理方法(Professional JavaScript for Web Developers)

var EventUtil = {
addHandler: function (element, type, handler) {
if (element.addEventListener) {
element.addEventListener(type, handler, false);
} else if (element.attachEvent) {
element.attachEvent("on" + type, handler);
} else {
element["on" + type] = handler;
}
},
getEvent: function (event) {
return event ? event : window.event;
},
getTarget: function (event) {
return event.target || event.srcElement;
},
preventDefault: function (event) {
if (event.preventDefault) {
event.preventDefault();
} else {
event.returnValue = false;
}
},
removeHandler: function (element, type, handler) {
if (element.removeEventListener) {
element.removeEventListener(type, handler, false);
} else if (element.detachEvent) {
element.detachEvent("on" + type, handler);
} else {
element["on" + type] = null;
}
},
getRelatedTarget: function (event) {
if (event.relatedTarget) {
return event.relatedTarget;
} else if (event.toElement) {
return event.toElement;
} else if (event.fromElement) {
return event.fromElement;
} else {
return null;
}
},
stopPropagation: function (event) {
if (event.stopPropagation) {
event.stopPropagation();
} else {
event.cancelBubble = true;
}
}
};