Mozilla中独有的读写器（defineGetter、defineSetter）以及可以给Element，Event等加上prototype原型，使得在IE里用的方法同样在Mozilla中可以适用，下面贴出常用的一些代码
例如
obj.insertAdjacentHTML, currentStyle, obj.attachEvent, obj.detachEvent等等。
版权属于Erik Arvidsson, webfx
extendEventObject();
emulateAttachEvent();
emulateEventHandlers(["click", "dblclick", "mouseover", "mouseout",
"mousedown", "mouseup", "mousemove",
"keydown", "keypress", "keyup"]);
emulateCurrentStyle();
/*emulateDocumentAll();
emulateElement()
*/
// It is better to use a constant for event.button
Event.LEFT = 0;
Event.MIDDLE = 1;
Event.RIGHT = 2;
}
else {
Event = {};
// IE is returning wrong button number
Event.LEFT = 1;
Event.MIDDLE = 4;
Event.RIGHT = 2;
}
/*
* Extends the event object with srcElement, cancelBubble, returnValue,
* fromElement and toElement
*/
function extendEventObject() {
Event.prototype.__defineSetter__("returnValue", function (b) {
if (!b) this.preventDefault();
return b;
});
Event.prototype.__defineSetter__("cancelBubble", function (b) {
if (b) this.stopPropagation();
return b;
});
Event.prototype.__defineGetter__("srcElement", function () {
var node = this.target;
while (node.nodeType != 1) node = node.parentNode;
return node;
});
Event.prototype.__defineGetter__("fromElement", function () {
var node;
if (this.type == "mouseover")
node = this.relatedTarget;
else if (this.type == "mouseout")
node = this.target;
if (!node) return;
while (node.nodeType != 1) node = node.parentNode;
return node;
});
Event.prototype.__defineGetter__("toElement", function () {
var node;
if (this.type == "mouseout")
node = this.relatedTarget;
else if (this.type == "mouseover")
node = this.target;
if (!node) return;
while (node.nodeType != 1) node = node.parentNode;
return node;
});
Event.prototype.__defineGetter__("offsetX", function () {
return this.layerX;
});
Event.prototype.__defineGetter__("offsetY", function () {
return this.layerY;
});
}
/*
* Emulates element.attachEvent as well as detachEvent
*/
function emulateAttachEvent() {
HTMLDocument.prototype.attachEvent =
HTMLElement.prototype.attachEvent = function (sType, fHandler) {
var shortTypeName = sType.replace(/on/, "");
fHandler._ieEmuEventHandler = function (e) {
window.event = e;
return fHandler();
};
this.addEventListener(shortTypeName, fHandler._ieEmuEventHandler, false);
};
HTMLDocument.prototype.detachEvent =
HTMLElement.prototype.detachEvent = function (sType, fHandler) {
var shortTypeName = sType.replace(/on/, "");
if (typeof fHandler._ieEmuEventHandler == "function")
this.removeEventListener(shortTypeName, fHandler._ieEmuEventHandler, false);
else
this.removeEventListener(shortTypeName, fHandler, true);
};
}
/*
* This function binds the event object passed along in an
* event to window.event
*/
function emulateEventHandlers(eventNames) {
for (var i = 0; i < eventNames.length; i++) {
document.addEventListener(eventNames[i], function (e) {
window.event = e;
}, true); // using capture
}
}
/*
* Simple emulation of document.all
* this one is far from complete. Be cautious
*/
function emulateAllModel() {
var allGetter = function () {
var a = this.getElementsByTagName("*");
var node = this;
a.tags = function (sTagName) {
return node.getElementsByTagName(sTagName);
};
return a;
};
HTMLDocument.prototype.__defineGetter__("all", allGetter);
HTMLElement.prototype.__defineGetter__("all", allGetter);
}
function extendElementModel() {
HTMLElement.prototype.__defineGetter__("parentElement", function () {
if (this.parentNode == this.ownerDocument) return null;
return this.parentNode;
});
HTMLElement.prototype.__defineGetter__("children", function () {
var tmp = [];
var j = 0;
var n;
for (var i = 0; i < this.childNodes.length; i++) {
n = this.childNodes[i];
if (n.nodeType == 1) {
tmp[j++] = n;
if (n.name) { // named children
if (!tmp[n.name])
tmp[n.name] = [];
tmp[n.name][tmp[n.name].length] = n;
}
if (n.id) // child with id
tmp[n.id] = n
}
}
return tmp;
});
HTMLElement.prototype.contains = function (oEl) {
if (oEl == this) return true;
if (oEl == null) return false;
return this.contains(oEl.parentNode);
};
}
function emulateCurrentStyle() {
HTMLElement.prototype.__defineGetter__("currentStyle", function () {
return this.ownerDocument.defaultView.getComputedStyle(this, null);
/*
var cs = {};
var el = this;
for (var i = 0; i < properties.length; i++) {
cs.__defineGetter__(properties[i], encapsulateObjects(el, properties[i]));
}
return cs;
*/
});
}
function emulateHTMLModel() {
// This function is used to generate a html string for the text properties/methods
// It replaces '\n' with "<BR"> as well as fixes consecutive white spaces
// It also repalaces some special characters
function convertTextToHTML(s) {
s = s.replace(/\&/g, "&").replace(/</g, "<").replace(/>/g, ">").replace(/\n/g, "<BR>");
while (/\s\s/.test(s))
s = s.replace(/\s\s/, " ");
return s.replace(/\s/g, " ");
}
HTMLElement.prototype.insertAdjacentHTML = function (sWhere, sHTML) {
var df; // : DocumentFragment
var r = this.ownerDocument.createRange();
switch (String(sWhere).toLowerCase()) {
case "beforebegin":
r.setStartBefore(this);
df = r.createContextualFragment(sHTML);
this.parentNode.insertBefore(df, this);
break;
case "afterbegin":
r.selectNodeContents(this);
r.collapse(true);
df = r.createContextualFragment(sHTML);
this.insertBefore(df, this.firstChild);
break;
case "beforeend":
r.selectNodeContents(this);
r.collapse(false);
df = r.createContextualFragment(sHTML);
this.appendChild(df);
break;
case "afterend":
r.setStartAfter(this);
df = r.createContextualFragment(sHTML);
this.parentNode.insertBefore(df, this.nextSibling);
break;
}
};
HTMLElement.prototype.__defineSetter__("outerHTML", function (sHTML) {
var r = this.ownerDocument.createRange();
r.setStartBefore(this);
var df = r.createContextualFragment(sHTML);
this.parentNode.replaceChild(df, this);
return sHTML;
});
HTMLElement.prototype.__defineGetter__("canHaveChildren", function () {
switch (this.tagName) {
case "AREA":
case "BASE":
case "BASEFONT":
case "COL":
case "FRAME":
case "HR":
case "IMG":
case "BR":
case "INPUT":
case "ISINDEX":
case "LINK":
case "META":
case "PARAM":
return false;
}
return true;
});
HTMLElement.prototype.__defineGetter__("outerHTML", function () {
var attr, attrs = this.attributes;
var str = "<" + this.tagName;
for (var i = 0; i < attrs.length; i++) {
attr = attrs[i];
if (attr.specified)
str += " " + attr.name + '="' + attr.value + '"';
}
if (!this.canHaveChildren)
return str + ">";
return str + ">" + this.innerHTML + "</" + this.tagName + ">";
});
HTMLElement.prototype.__defineSetter__("innerText", function (sText) {
this.innerHTML = convertTextToHTML(sText);
return sText;
});
var tmpGet;
HTMLElement.prototype.__defineGetter__("innerText", tmpGet = function () {
var r = this.ownerDocument.createRange();
r.selectNodeContents(this);
return r.toString();
});
HTMLElement.prototype.__defineSetter__("outerText", function (sText) {
this.outerHTML = convertTextToHTML(sText);
return sText;
});
HTMLElement.prototype.__defineGetter__("outerText", tmpGet);
HTMLElement.prototype.insertAdjacentText = function (sWhere, sText) {
this.insertAdjacentHTML(sWhere, convertTextToHTML(sText));
};
}