javascript获得DOM元素X,Y坐标的函数

javascript获得DOM元素X,Y坐标的函数

以下是YUI用的函数：

isSafari = (document.childNodes && !document.all && !navigator.taintEnabled);
    var getXY = function(el) {
        if (document.documentElement.getBoundingClientRect) { // IE
            var box = el.getBoundingClientRect();

            var rootNode = el.ownerDocument;
            return [box.left + getDocumentScrollLeft(rootNode), box.top +
                    getDocumentScrollTop(rootNode)];
        } else {
            var pos = [el.offsetLeft, el.offsetTop];
            var parentNode = el.offsetParent;

            // safari: subtract body offsets if el is abs (or any offsetParent), unless body is offsetParent
            var accountForBody = (isSafari &&
                    el.style['position'] == 'absolute' &&
                    el.offsetParent == el.ownerDocument.body);

            if (parentNode != el) {
                while (parentNode) {
                    pos[0] += parentNode.offsetLeft;
                    pos[1] += parentNode.offsetTop;
                    if (!accountForBody && isSafari &&
                            parentNode.style['position'] == 'absolute' ) {
                        accountForBody = true;
                    }
                    parentNode = parentNode.offsetParent;
                }
            }

            if (accountForBody) { //safari doubles in this case
                pos[0] -= el.ownerDocument.body.offsetLeft;
                pos[1] -= el.ownerDocument.body.offsetTop;
            }
            parentNode = el.parentNode;

            // account for any scrolled ancestors
            while ( parentNode.tagName && !/^body|html$/i.test(parentNode.tagName) )
            {
               // work around opera inline/table scrollLeft/Top bug
               if (parentNode.style['display'].search(/^inline|table-row.*$/i)) {
                    pos[0] -= parentNode.scrollLeft;
                    pos[1] -= parentNode.scrollTop;
                }

                parentNode = parentNode.parentNode;
            }

            return pos;
        }
    }

    /**
     * Returns the left scroll value of the document
     * @method getDocumentScrollLeft
     * @param {HTMLDocument} document (optional) The document to get the scroll value of
     * @return {Int}  The amount that the document is scrolled to the left
     */
    getDocumentScrollLeft = function(doc) {
        doc = doc || document;
        return Math.max(doc.documentElement.scrollLeft, doc.body.scrollLeft);
    },

    /**
     * Returns the top scroll value of the document
     * @method getDocumentScrollTop
     * @param {HTMLDocument} document (optional) The document to get the scroll value of
     * @return {Int}  The amount that the document is scrolled to the top
     */
    getDocumentScrollTop = function(doc) {
        doc = doc || document;
        return Math.max(doc.documentElement.scrollTop, doc.body.scrollTop);
    }

 下面是精简版：

function getX(obj){
        return obj.offsetLeft + (obj.offsetParent ? getX(obj.offsetParent) : obj.x ? obj.x : 0);
    }
    function getY(obj){
        return (obj.offsetParent ? obj.offsetTop + getY(obj.offsetParent) : obj.y ? obj.y : 0);
    }

 不过只支持IE和FF