    //@tag dom,core
    //@require Helper.js
    //@define Ext.dom.Query
    //@define Ext.core.Query
    //@define Ext.DomQuery

    /*
     * This is code is also distributed under MIT license for use
     * with jQuery and prototype JavaScript libraries.
     */
    /**
     * @class Ext.dom.Query
     * @alternateClassName Ext.DomQuery
     * @alternateClassName Ext.core.DomQuery
     * @singleton
     *
     * Provides high performance selector/xpath processing by compiling queries into reusable functions. New pseudo classes
     * and matchers can be plugged. It works on HTML and XML documents (if a content node is passed in).
     *
     * DomQuery supports most of the [CSS3 selectors spec][1], along with some custom selectors and basic XPath.
     *
     * All selectors, attribute filters and pseudos below can be combined infinitely in any order. For example
     * `div.foo:nth-child(odd)[@foo=bar].bar:first` would be a perfectly valid selector. Node filters are processed
     * in the order in which they appear, which allows you to optimize your queries for your document structure.
     *
     * ## Element Selectors:
     *
     *   - **`*`** any element
     *   - **`E`** an element with the tag E
     *   - **`E F`** All descendent elements of E that have the tag F
     *   - **`E > F`** or **E/F** all direct children elements of E that have the tag F
     *   - **`E + F`** all elements with the tag F that are immediately preceded by an element with the tag E
     *   - **`E ~ F`** all elements with the tag F that are preceded by a sibling element with the tag E
     *
     * ## Attribute Selectors:
     *
     * The use of `@` and quotes are optional. For example, `div[@foo='bar']` is also a valid attribute selector.
     *
     *   - **`E[foo]`** has an attribute "foo"
     *   - **`E[foo=bar]`** has an attribute "foo" that equals "bar"
     *   - **`E[foo^=bar]`** has an attribute "foo" that starts with "bar"
     *   - **`E[foo$=bar]`** has an attribute "foo" that ends with "bar"
     *   - **`E[foo*=bar]`** has an attribute "foo" that contains the substring "bar"
     *   - **`E[foo%=2]`** has an attribute "foo" that is evenly divisible by 2
     *   - **`E[foo!=bar]`** attribute "foo" does not equal "bar"
     *
     * ## Pseudo Classes:
     *
     *   - **`E:first-child`** E is the first child of its parent
     *   - **`E:last-child`** E is the last child of its parent
     *   - **`E:nth-child(_n_)`** E is the _n_th child of its parent (1 based as per the spec)
     *   - **`E:nth-child(odd)`** E is an odd child of its parent
     *   - **`E:nth-child(even)`** E is an even child of its parent
     *   - **`E:only-child`** E is the only child of its parent
     *   - **`E:checked`** E is an element that is has a checked attribute that is true (e.g. a radio or checkbox)
     *   - **`E:first`** the first E in the resultset
     *   - **`E:last`** the last E in the resultset
     *   - **`E:nth(_n_)`** the _n_th E in the resultset (1 based)
     *   - **`E:odd`** shortcut for :nth-child(odd)
     *   - **`E:even`** shortcut for :nth-child(even)
     *   - **`E:contains(foo)`** E's innerHTML contains the substring "foo"
     *   - **`E:nodeValue(foo)`** E contains a textNode with a nodeValue that equals "foo"
     *   - **`E:not(S)`** an E element that does not match simple selector S
     *   - **`E:has(S)`** an E element that has a descendent that matches simple selector S
     *   - **`E:next(S)`** an E element whose next sibling matches simple selector S
     *   - **`E:prev(S)`** an E element whose previous sibling matches simple selector S
     *   - **`E:any(S1|S2|S2)`** an E element which matches any of the simple selectors S1, S2 or S3
     *   - **`E:visible(true)`** an E element which is deeply visible according to {@link Ext.dom.Element#isVisible}
     *
     * ## CSS Value Selectors:
     *
     *   - **`E{display=none}`** css value "display" that equals "none"
     *   - **`E{display^=none}`** css value "display" that starts with "none"
     *   - **`E{display$=none}`** css value "display" that ends with "none"
     *   - **`E{display*=none}`** css value "display" that contains the substring "none"
     *   - **`E{display%=2}`** css value "display" that is evenly divisible by 2
     *   - **`E{display!=none}`** css value "display" that does not equal "none"
     *
     * ## XML Namespaces:
     *   - **`ns|E`** an element with tag E and namespace prefix ns
     *
     * [1]: http://www.w3.org/TR/2005/WD-css3-selectors-20051215/#selectors
     */
    Ext.ns('Ext.core');

    Ext.dom.Query = Ext.core.DomQuery = Ext.DomQuery = (function() {
        var DQ,
            doc = document,
            cache = {},
            simpleCache = {},
            valueCache = {},
            useClassList = !!doc.documentElement.classList,
            useElementPointer = !!doc.documentElement.firstElementChild,
            useChildrenCollection = (function() {
                var d = doc.createElement('div');
                d.innerHTML = '<!-- -->text<!-- -->';
                return d.children && (d.children.length === 0);
            })(),
            nonSpace = /\S/,
            trimRe = /^\s+|\s+$/g,
            tplRe = /\{(\d+)\}/g,
            modeRe = /^(\s?[\/>+~]\s?|\s|$)/,
            tagTokenRe = /^(#)?([\w\-\*\|\\]+)/,
            nthRe = /(\d*)n\+?(\d*)/,
            nthRe2 = /\D/,
            startIdRe = /^\s*#/,
            // This is for IE MSXML which does not support expandos.
            // IE runs the same speed using setAttribute, however FF slows way down
            // and Safari completely fails so they need to continue to use expandos.
            isIE = window.ActiveXObject ? true : false,
            key = 30803,
            longHex = /\\([0-9a-fA-F]{6})/g,
            shortHex = /\\([0-9a-fA-F]{1,6})\s{0,1}/g,
            nonHex = /\\([^0-9a-fA-F]{1})/g,
            escapes = /\\/g,
            num, hasEscapes,
            // True if the browser supports the following syntax:
            // document.getElementsByTagName('namespacePrefix:tagName')
            supportsColonNsSeparator = (function () {
                var xmlDoc,
                    xmlString = '<r><a:b xmlns:a="n"></a:b></r>';

                if (window.DOMParser) {
                    xmlDoc = (new DOMParser()).parseFromString(xmlString, "application/xml");
                } else {
                    xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
                    xmlDoc.loadXML(xmlString);
                }

                return !!xmlDoc.getElementsByTagName('a:b').length;
            })(),

            // replaces a long hex regex match group with the appropriate ascii value
            // $args indicate regex match pos
            longHexToChar = function($0, $1) {
                return String.fromCharCode(parseInt($1, 16));
            },

            // converts a shortHex regex match to the long form
            shortToLongHex = function($0, $1) {
                while ($1.length < 6) {
                    $1 = '0' + $1;
                }
                return '\\' + $1;
            },

            // converts a single char escape to long escape form
            charToLongHex = function($0, $1) {
                num = $1.charCodeAt(0).toString(16);
                if (num.length === 1) {
                    num = '0' + num;
                }
                return '\\0000' + num;
            },

            // Un-escapes an input selector string.  Assumes all escape sequences have been
            // normalized to the css '\\0000##' 6-hex-digit style escape sequence :
            // will not handle any other escape formats
            unescapeCssSelector = function(selector) {
                return (hasEscapes)
                    ? selector.replace(longHex, longHexToChar)
                    : selector;
            },

            // checks if the path has escaping & does any appropriate replacements
            setupEscapes = function(path) {
                hasEscapes = (path.indexOf('\\') > -1);
                if (hasEscapes) {
                    path = path
                        .replace(shortHex, shortToLongHex)
                        .replace(nonHex, charToLongHex)
                        .replace(escapes, '\\\\');  // double the '\' for js compilation
                }
                return path;
            };

        // this eval is stop the compressor from
        // renaming the variable to something shorter
        eval("var batch = 30803, child, next, prev, byClassName;");

        // Retrieve the child node from a particular
        // parent at the specified index.
        child = useChildrenCollection ?
            function child(parent, index) {
                return parent.children[index]
            } :
            function child(parent, index) {
                var i = 0,
                    n = parent.firstChild;
                while (n) {
                    if (n.nodeType == 1) {
                        if (++i == index) {
                            return n;
                        }
                    }
                    n = n.nextSibling;
                }
                return null;
            };

        // retrieve the next element node
        next = useElementPointer ?
            function(n) {
                return n.nextElementSibling;
            } :
            function(n) {
                while ((n = n.nextSibling) && n.nodeType != 1);
                return n;
            };

        // retrieve the previous element node
        prev = useElementPointer ?
            function(n) {
                return n.previousElementSibling;
            } :
            function(n) {
                while ((n = n.previousSibling) && n.nodeType != 1);
                return n;
            };

        // Mark each child node with a nodeIndex skipping and
        // removing empty text nodes.
        function children(parent) {
            var n = parent.firstChild,
                nodeIndex = -1,
                nextNode;

            while (n) {
                nextNode = n.nextSibling;
                // clean worthless empty nodes.
                if (n.nodeType == 3 && !nonSpace.test(n.nodeValue)) {
                    parent.removeChild(n);
                } else {
                    // add an expando nodeIndex
                    n.nodeIndex = ++nodeIndex;
                }
                n = nextNode;
            }
            return this;
        }

        // nodeSet - array of nodes
        // cls - CSS Class
        byClassName = useClassList ? // Use classList API where available: http://jsperf.com/classlist-vs-old-school-check/
            function (nodeSet, cls) {
                cls = unescapeCssSelector(cls);
                if (!cls) {
                    return nodeSet;
                }
                var result = [], ri = -1,
                    i, ci, classList;

                for (i = 0; ci = nodeSet[i]; i++) {
                    classList = ci.classList;
                    if (classList) {
                        if (classList.contains(cls)) {
                            result[++ri] = ci;
                        }
                    } else if ((' ' + ci.className + ' ').indexOf(cls) !== -1) {
                        // Some elements types (SVG) may not always have a classList
                        // in some browsers, so fallback to the old style here
                        result[++ri] = ci;
                    }
                }
                return result;
            } :
            function (nodeSet, cls) {
                cls = unescapeCssSelector(cls);
                if (!cls) {
                    return nodeSet;
                }
                var result = [], ri = -1,
                    i, ci;

                for (i = 0; ci = nodeSet[i]; i++) {
                    if ((' ' + ci.className + ' ').indexOf(cls) !== -1) {
                        result[++ri] = ci;
                    }
                }
                return result;
            };

        function attrValue(n, attr) {
            // if its an array, use the first node.
            if (!n.tagName && typeof n.length != "undefined") {
                n = n[0];
            }
            if (!n) {
                return null;
            }

            if (attr == "for") {
                return n.htmlFor;
            }
            if (attr == "class" || attr == "className") {
                return n.className;
            }
            return n.getAttribute(attr) || n[attr];

        }

        // ns - nodes
        // mode - false, /, >, +, ~
        // tagName - defaults to "*"
        function getNodes(ns, mode, tagName) {
            var result = [], ri = -1, cs,
                i, ni, j, ci, cn, utag, n, cj;
            if (!ns) {
                return result;
            }
            tagName = tagName.replace('|', ':') || "*";
            // convert to array
            if (typeof ns.getElementsByTagName != "undefined") {
                ns = [ns];
            }

            // no mode specified, grab all elements by tagName
            // at any depth
            if (!mode) {
                tagName = unescapeCssSelector(tagName);
                if (!supportsColonNsSeparator && DQ.isXml(ns[0]) &&
                    tagName.indexOf(':') !== -1) {
                    // Some browsers (e.g. WebKit and Opera do not support the following syntax
                    // in xml documents: getElementsByTagName('ns:tagName'). To work around
                    // this, we remove the namespace prefix from the tagName, get the elements
                    // by tag name only, and then compare each element's tagName property to
                    // the tagName with namespace prefix attached to ensure that the tag is in
                    // the proper namespace.
                    for (i = 0; ni = ns[i]; i++) {
                        cs = ni.getElementsByTagName(tagName.split(':').pop());
                        for (j = 0; ci = cs[j]; j++) {
                            if (ci.tagName === tagName) {
                                result[++ri] = ci;
                            }
                        }
                    }
                } else {
                    for (i = 0; ni = ns[i]; i++) {
                        cs = ni.getElementsByTagName(tagName);
                        for (j = 0; ci = cs[j]; j++) {
                            result[++ri] = ci;
                        }
                    }
                }
                // Direct Child mode (/ or >)
                // E > F or E/F all direct children elements of E that have the tag
            } else if (mode == "/" || mode == ">") {
                utag = tagName.toUpperCase();
                for (i = 0; ni = ns[i]; i++) {
                    cn = ni.childNodes;
                    for (j = 0; cj = cn[j]; j++) {
                        if (cj.nodeName == utag || cj.nodeName == tagName || tagName == '*') {
                            result[++ri] = cj;
                        }
                    }
                }
                // Immediately Preceding mode (+)
                // E + F all elements with the tag F that are immediately preceded by an element with the tag E
            } else if (mode == "+") {
                utag = tagName.toUpperCase();
                for (i = 0; n = ns[i]; i++) {
                    while ((n = n.nextSibling) && n.nodeType != 1);
                    if (n && (n.nodeName == utag || n.nodeName == tagName || tagName == '*')) {
                        result[++ri] = n;
                    }
                }
                // Sibling mode (~)
                // E ~ F all elements with the tag F that are preceded by a sibling element with the tag E
            } else if (mode == "~") {
                utag = tagName.toUpperCase();
                for (i = 0; n = ns[i]; i++) {
                    while ((n = n.nextSibling)) {
                        if (n.nodeName == utag || n.nodeName == tagName || tagName == '*') {
                            result[++ri] = n;
                        }
                    }
                }
            }
            return result;
        }

        function concat(a, b) {
            a.push.apply(a, b);
            return a;
        }

        function byTag(cs, tagName) {
            if (cs.tagName || cs === doc) {
                cs = [cs];
            }
            if (!tagName) {
                return cs;
            }
            var result = [], ri = -1,
                i, ci;
            tagName = tagName.toLowerCase();
            for (i = 0; ci = cs[i]; i++) {
                if (ci.nodeType == 1 && ci.tagName.toLowerCase() == tagName) {
                    result[++ri] = ci;
                }
            }
            return result;
        }

        function byId(cs, id) {
            id = unescapeCssSelector(id);
            if (cs.tagName || cs === doc) {
                cs = [cs];
            }
            if (!id) {
                return cs;
            }
            var result = [], ri = -1,
                i, ci;
            for (i = 0; ci = cs[i]; i++) {
                if (ci && ci.id == id) {
                    result[++ri] = ci;
                    return result;
                }
            }
            return result;
        }

        // operators are =, !=, ^=, $=, *=, %=, |= and ~=
        // custom can be "{"
        function byAttribute(cs, attr, value, op, custom) {
            var result = [],
                ri = -1,
                useGetStyle = custom == "{",
                fn = DQ.operators[op],
                a,
                xml,
                hasXml,
                i, ci;

            value = unescapeCssSelector(value);

            for (i = 0; ci = cs[i]; i++) {
                // skip non-element nodes.
                if (ci.nodeType === 1) {
                    // only need to do this for the first node
                    if (!hasXml) {
                        xml = DQ.isXml(ci);
                        hasXml = true;
                    }

                    // we only need to change the property names if we're dealing with html nodes, not XML
                    if (!xml) {
                        if (useGetStyle) {
                            a = DQ.getStyle(ci, attr);
                        } else if (attr == "class" || attr == "className") {
                            a = ci.className;
                        } else if (attr == "for") {
                            a = ci.htmlFor;
                        } else if (attr == "href") {
                            // getAttribute href bug
                            // http://www.glennjones.net/Post/809/getAttributehrefbug.htm
                            a = ci.getAttribute("href", 2);
                        } else {
                            a = ci.getAttribute(attr);
                        }
                    } else {
                        a = ci.getAttribute(attr);
                    }
                    if ((fn && fn(a, value)) || (!fn && a)) {
                        result[++ri] = ci;
                    }
                }
            }
            return result;
        }

        function byPseudo(cs, name, value) {
            value = unescapeCssSelector(value);
            return DQ.pseudos[name](cs, value);
        }

        function nodupIEXml(cs) {
            var d = ++key,
                r,
                i, len, c;
            cs[0].setAttribute("_nodup", d);
            r = [cs[0]];
            for (i = 1, len = cs.length; i < len; i++) {
                c = cs[i];
                if (!c.getAttribute("_nodup") != d) {
                    c.setAttribute("_nodup", d);
                    r[r.length] = c;
                }
            }
            for (i = 0, len = cs.length; i < len; i++) {
                cs[i].removeAttribute("_nodup");
            }
            return r;
        }

        function nodup(cs) {
            if (!cs) {
                return [];
            }
            var len = cs.length, c, i, r = cs, cj, ri = -1, d, j;
            if (!len || typeof cs.nodeType != "undefined" || len == 1) {
                return cs;
            }
            if (isIE && typeof cs[0].selectSingleNode != "undefined") {
                return nodupIEXml(cs);
            }
            d = ++key;
            cs[0]._nodup = d;
            for (i = 1; c = cs[i]; i++) {
                if (c._nodup != d) {
                    c._nodup = d;
                } else {
                    r = [];
                    for (j = 0; j < i; j++) {
                        r[++ri] = cs[j];
                    }
                    for (j = i + 1; cj = cs[j]; j++) {
                        if (cj._nodup != d) {
                            cj._nodup = d;
                            r[++ri] = cj;
                        }
                    }
                    return r;
                }
            }
            return r;
        }

        function quickDiffIEXml(c1, c2) {
            var d = ++key,
                r = [],
                i, len;
            for (i = 0, len = c1.length; i < len; i++) {
                c1[i].setAttribute("_qdiff", d);
            }
            for (i = 0, len = c2.length; i < len; i++) {
                if (c2[i].getAttribute("_qdiff") != d) {
                    r[r.length] = c2[i];
                }
            }
            for (i = 0, len = c1.length; i < len; i++) {
                c1[i].removeAttribute("_qdiff");
            }
            return r;
        }

        function quickDiff(c1, c2) {
            var len1 = c1.length,
                d = ++key,
                r = [],
                i, len;
            if (!len1) {
                return c2;
            }
            if (isIE && typeof c1[0].selectSingleNode != "undefined") {
                return quickDiffIEXml(c1, c2);
            }
            for (i = 0; i < len1; i++) {
                c1[i]._qdiff = d;
            }
            for (i = 0, len = c2.length; i < len; i++) {
                if (c2[i]._qdiff != d) {
                    r[r.length] = c2[i];
                }
            }
            return r;
        }

        function quickId(ns, mode, root, id) {
            if (ns == root) {
                id = unescapeCssSelector(id);
                var d = root.ownerDocument || root;
                return d.getElementById(id);
            }
            ns = getNodes(ns, mode, "*");
            return byId(ns, id);
        }

        return DQ = {
            getStyle: function(el, name) {
                return Ext.fly(el, '_DomQuery').getStyle(name);
            },
            /**
             * Compiles a selector/xpath query into a reusable function. The returned function
             * takes one parameter "root" (optional), which is the context node from where the query should start.
             * @param {String} selector The selector/xpath query
             * @param {String} [type="select"] Either "select" or "simple" for a simple selector match
             * @return {Function}
             */
            compile: function(path, type) {
                type = type || "select";

                // setup fn preamble
                var fn = ["var f = function(root) {\n var mode; ++batch; var n = root || document;\n"],
                    lastPath,
                    matchers = DQ.matchers,
                    matchersLn = matchers.length,
                    modeMatch,
                    // accept leading mode switch
                    lmode = path.match(modeRe),
                    tokenMatch, matched, j, t, m;

                path = setupEscapes(path);

                if (lmode && lmode[1]) {
                    fn[fn.length] = 'mode="' + lmode[1].replace(trimRe, "") + '";';
                    path = path.replace(lmode[1], "");
                }

                // strip leading slashes
                while (path.substr(0, 1) == "/") {
                    path = path.substr(1);
                }

                while (path && lastPath != path) {
                    lastPath = path;
                    tokenMatch = path.match(tagTokenRe);
                    if (type == "select") {
                        if (tokenMatch) {
                            // ID Selector
                            if (tokenMatch[1] == "#") {
                                fn[fn.length] = 'n = quickId(n, mode, root, "' + tokenMatch[2] + '");';
                            } else {
                                fn[fn.length] = 'n = getNodes(n, mode, "' + tokenMatch[2] + '");';
                            }
                            path = path.replace(tokenMatch[0], "");
                        } else if (path.substr(0, 1) != '@') {
                            fn[fn.length] = 'n = getNodes(n, mode, "*");';
                        }
                        // type of "simple"
                    } else {
                        if (tokenMatch) {
                            if (tokenMatch[1] == "#") {
                                fn[fn.length] = 'n = byId(n, "' + tokenMatch[2] + '");';
                            } else {
                                fn[fn.length] = 'n = byTag(n, "' + tokenMatch[2] + '");';
                            }
                            path = path.replace(tokenMatch[0], "");
                        }
                    }
                    while (!(modeMatch = path.match(modeRe))) {
                        matched = false;
                        for (j = 0; j < matchersLn; j++) {
                            t = matchers[j];
                            m = path.match(t.re);
                            if (m) {
                                fn[fn.length] = t.select.replace(tplRe, function(x, i) {
                                    return m[i];
                                });
                                path = path.replace(m[0], "");
                                matched = true;
                                break;
                            }
                        }
                        // prevent infinite loop on bad selector
                        if (!matched) {
                            Ext.Error.raise({
                                sourceClass:'Ext.DomQuery',
                                sourceMethod:'compile',
                                msg:'Error parsing selector. Parsing failed at "' + path + '"'
                            });
                        }
                    }
                    if (modeMatch[1]) {
                        fn[fn.length] = 'mode="' + modeMatch[1].replace(trimRe, "") + '";';
                        path = path.replace(modeMatch[1], "");
                    }
                }
                // close fn out
                fn[fn.length] = "return nodup(n);\n}";

                // eval fn and return it
                eval(fn.join(""));
                return f;
            },

            /**
             * Selects an array of DOM nodes using JavaScript-only implementation.
             *
             * Use {@link #select} to take advantage of browsers built-in support for CSS selectors.
             * @param {String} selector The selector/xpath query (can be a comma separated list of selectors)
             * @param {HTMLElement/String} [root=document] The start of the query.
             * @return {HTMLElement[]} An Array of DOM elements which match the selector. If there are
             * no matches, and empty Array is returned.
             */
            jsSelect: function(path, root, type) {
                // set root to doc if not specified.
                root = root || doc;

                if (typeof root == "string") {
                    root = doc.getElementById(root);
                }
                var paths = path.split(","),
                    results = [],
                    i, len, subPath, result;

                // loop over each selector
                for (i = 0, len = paths.length; i < len; i++) {
                    subPath = paths[i].replace(trimRe, "");
                    // compile and place in cache
                    if (!cache[subPath]) {
                        // When we compile, escaping is handled inside the compile method
                        cache[subPath] = DQ.compile(subPath, type);
                        if (!cache[subPath]) {
                            Ext.Error.raise({
                                sourceClass:'Ext.DomQuery',
                                sourceMethod:'jsSelect',
                                msg:subPath + ' is not a valid selector'
                            });
                        }
                    } else {
                        // If we've already compiled, we still need to check if the
                        // selector has escaping and setup the appropriate flags
                        setupEscapes(subPath);
                    }
                    result = cache[subPath](root);
                    if (result && result !== doc) {
                        results = results.concat(result);
                    }
                }

                // if there were multiple selectors, make sure dups
                // are eliminated
                if (paths.length > 1) {
                    return nodup(results);
                }
                return results;
            },

            isXml: function(el) {
                var docEl = (el ? el.ownerDocument || el : 0).documentElement;
                return docEl ? docEl.nodeName !== "HTML" : false;
            },

            /**
             * Selects an array of DOM nodes by CSS/XPath selector.
             *
             * Uses [document.querySelectorAll][0] if browser supports that, otherwise falls back to
             * {@link Ext.dom.Query#jsSelect} to do the work.
             *
             * Aliased as {@link Ext#query}.
             *
             * [0]: https://developer.mozilla.org/en/DOM/document.querySelectorAll
             *
             * @param {String} path The selector/xpath query
             * @param {HTMLElement} [root=document] The start of the query.
             * @return {HTMLElement[]} An array of DOM elements (not a NodeList as returned by `querySelectorAll`).
             * @param {String} [type="select"] Either "select" or "simple" for a simple selector match (only valid when
             * used when the call is deferred to the jsSelect method)
             * @param {Boolean} [single] Pass `true` to select only the first matching node using `document.querySelector` (where available)
             * @method
             */
            select : doc.querySelectorAll ? function(path, root, type, single) {
                root = root || doc;
                if (!DQ.isXml(root)) {
                    try {
                        /*
                         * This checking here is to "fix" the behaviour of querySelectorAll
                         * for non root document queries. The way qsa works is intentional,
                         * however it's definitely not the expected way it should work.
                         * When descendant selectors are used, only the lowest selector must be inside the root!
                         * More info: http://ejohn.org/blog/thoughts-on-queryselectorall/
                         * So we create a descendant selector by prepending the root's ID, and query the parent node.
                         * UNLESS the root has no parent in which qsa will work perfectly.
                         *
                         * We only modify the path for single selectors (ie, no multiples),
                         * without a full parser it makes it difficult to do this correctly.
                         */
                        if (root.parentNode && (root.nodeType !== 9) && path.indexOf(',') === -1 && !startIdRe.test(path)) {
                            path = '#' + Ext.escapeId(Ext.id(root)) + ' ' + path;
                            root = root.parentNode;
                        }
                        return single ? [ root.querySelector(path) ]
                            : Ext.Array.toArray(root.querySelectorAll(path));
                    }
                    catch (e) {
                    }
                }
                return DQ.jsSelect.call(this, path, root, type);
            } : function(path, root, type) {
                return DQ.jsSelect.call(this, path, root, type);
            },

            /**
             * Selects a single element.
             * @param {String} selector The selector/xpath query
             * @param {HTMLElement} [root=document] The start of the query.
             * @return {HTMLElement} The DOM element which matched the selector.
             */
            selectNode : function(path, root){
                return Ext.DomQuery.select(path, root, null, true)[0];
            },

            /**
             * Selects the value of a node, optionally replacing null with the defaultValue.
             * @param {String} selector The selector/xpath query
             * @param {HTMLElement} [root=document] The start of the query.
             * @param {String} [defaultValue] When specified, this is return as empty value.
             * @return {String}
             */
            selectValue: function(path, root, defaultValue) {
                path = path.replace(trimRe, "");
                if (!valueCache[path]) {
                    valueCache[path] = DQ.compile(path, "select");
                } else {
                    setupEscapes(path);
                }

                var n = valueCache[path](root),
                    v;

                n = n[0] ? n[0] : n;

                // overcome a limitation of maximum textnode size
                // Rumored to potentially crash IE6 but has not been confirmed.
                // http://reference.sitepoint.com/javascript/Node/normalize
                // https://developer.mozilla.org/En/DOM/Node.normalize
                if (typeof n.normalize == 'function') {
                    n.normalize();
                }

                v = (n && n.firstChild ? n.firstChild.nodeValue : null);
                return ((v === null || v === undefined || v === '') ? defaultValue : v);
            },

            /**
             * Selects the value of a node, parsing integers and floats.
             * Returns the defaultValue, or 0 if none is specified.
             * @param {String} selector The selector/xpath query
             * @param {HTMLElement} [root=document] The start of the query.
             * @param {Number} [defaultValue] When specified, this is return as empty value.
             * @return {Number}
             */
            selectNumber: function(path, root, defaultValue) {
                var v = DQ.selectValue(path, root, defaultValue || 0);
                return parseFloat(v);
            },

            /**
             * Returns true if the passed element(s) match the passed simple selector
             * (e.g. `div.some-class` or `span:first-child`)
             * @param {String/HTMLElement/HTMLElement[]} el An element id, element or array of elements
             * @param {String} selector The simple selector to test
             * @return {Boolean}
             */
            is: function(el, ss) {
                if (typeof el == "string") {
                    el = doc.getElementById(el);
                }
                var isArray = Ext.isArray(el),
                    result = DQ.filter(isArray ? el : [el], ss);
                return isArray ? (result.length == el.length) : (result.length > 0);
            },

            /**
             * Filters an array of elements to only include matches of a simple selector
             * (e.g. `div.some-class` or `span:first-child`)
             * @param {HTMLElement[]} el An array of elements to filter
             * @param {String} selector The simple selector to test
             * @param {Boolean} nonMatches If true, it returns the elements that DON'T match the selector instead of the
             * ones that match
             * @return {HTMLElement[]} An Array of DOM elements which match the selector. If there are no matches, and empty
             * Array is returned.
             */
            filter: function(els, ss, nonMatches) {
                ss = ss.replace(trimRe, "");
                if (!simpleCache[ss]) {
                    simpleCache[ss] = DQ.compile(ss, "simple");
                } else {
                    setupEscapes(ss);
                }

                var result = simpleCache[ss](els);
                return nonMatches ? quickDiff(result, els) : result;
            },

            /**
             * Collection of matching regular expressions and code snippets.
             * Each capture group within `()` will be replace the `{}` in the select
             * statement as specified by their index.
             */
            matchers: [{
                re: /^\.([\w\-\\]+)/,
                select: useClassList ? 'n = byClassName(n, "{1}");' : 'n = byClassName(n, " {1} ");'
            }, {
                re: /^\:([\w\-]+)(?:\(((?:[^\s>\/]*|.*?))\))?/,
                select: 'n = byPseudo(n, "{1}", "{2}");'
            },  {
                re: /^(?:([\[\{])(?:@)?([\w\-]+)\s?(?:(=|.=)\s?['"]?(.*?)["']?)?[\]\}])/,
                select: 'n = byAttribute(n, "{2}", "{4}", "{3}", "{1}");'
            }, {
                re: /^#([\w\-\\]+)/,
                select: 'n = byId(n, "{1}");'
            }, {
                re: /^@([\w\-\.]+)/,
                select: 'return {firstChild:{nodeValue:attrValue(n, "{1}")}};'
            }],

            /**
             * Collection of operator comparison functions.
             * The default operators are `=`, `!=`, `^=`, `$=`, `*=`, `%=`, `|=` and `~=`.
             *
             * New operators can be added as long as the match the format *c*`=` where *c*
             * is any character other than space, `>`, or `<`.
             *
             * Operator functions are passed the following parameters:
             *
             * * `propValue` : The property value to test.
             * * `compareTo` : The value to compare to.
             */
            operators: {
                "=": function(a, v) {
                    return a == v;
                },
                "!=": function(a, v) {
                    return a != v;
                },
                "^=": function(a, v) {
                    return a && a.substr(0, v.length) == v;
                },
                "$=": function(a, v) {
                    return a && a.substr(a.length - v.length) == v;
                },
                "*=": function(a, v) {
                    return a && a.indexOf(v) !== -1;
                },
                "%=": function(a, v) {
                    return (a % v) == 0;
                },
                "|=": function(a, v) {
                    return a && (a == v || a.substr(0, v.length + 1) == v + '-');
                },
                "~=": function(a, v) {
                    return a && (' ' + a + ' ').indexOf(' ' + v + ' ') != -1;
                }
            },

            /**
             * Object hash of "pseudo class" filter functions which are used when filtering selections.
             * Each function is passed two parameters:
             *
             * - **c** : Array
             *     An Array of DOM elements to filter.
             *
             * - **v** : String
             *     The argument (if any) supplied in the selector.
             *
             * A filter function returns an Array of DOM elements which conform to the pseudo class.
             * In addition to the provided pseudo classes listed above such as `first-child` and `nth-child`,
             * developers may add additional, custom psuedo class filters to select elements according to application-specific requirements.
             *
             * For example, to filter `a` elements to only return links to __external__ resources:
             *
             *     Ext.DomQuery.pseudos.external = function(c, v) {
             *         var r = [], ri = -1;
             *         for(var i = 0, ci; ci = c[i]; i++) {
             *             // Include in result set only if it's a link to an external resource
             *             if (ci.hostname != location.hostname) {
             *                 r[++ri] = ci;
             *             }
             *         }
             *         return r;
             *     };
             *
             * Then external links could be gathered with the following statement:
             *
             *     var externalLinks = Ext.select("a:external");
             */
            pseudos: {
                "first-child": function(c) {
                    var r = [], ri = -1, n,
                        i, ci;
                    for (i = 0; (ci = n = c[i]); i++) {
                        while ((n = n.previousSibling) && n.nodeType != 1);
                        if (!n) {
                            r[++ri] = ci;
                        }
                    }
                    return r;
                },

                "last-child": function(c) {
                    var r = [], ri = -1, n,
                        i, ci;
                    for (i = 0; (ci = n = c[i]); i++) {
                        while ((n = n.nextSibling) && n.nodeType != 1);
                        if (!n) {
                            r[++ri] = ci;
                        }
                    }
                    return r;
                },

                "nth-child": function(c, a) {
                    var r = [], ri = -1,
                        m = nthRe.exec(a == "even" && "2n" || a == "odd" && "2n+1" || !nthRe2.test(a) && "n+" + a || a),
                        f = (m[1] || 1) - 0, l = m[2] - 0,
                        i, n, j, cn, pn;
                    for (i = 0; n = c[i]; i++) {
                        pn = n.parentNode;
                        if (batch != pn._batch) {
                            j = 0;
                            for (cn = pn.firstChild; cn; cn = cn.nextSibling) {
                                if (cn.nodeType == 1) {
                                    cn.nodeIndex = ++j;
                                }
                            }
                            pn._batch = batch;
                        }
                        if (f == 1) {
                            if (l == 0 || n.nodeIndex == l) {
                                r[++ri] = n;
                            }
                        } else if ((n.nodeIndex + l) % f == 0) {
                            r[++ri] = n;
                        }
                    }

                    return r;
                },

                "only-child": function(c) {
                    var r = [], ri = -1,
                        i, ci;
                    for (i = 0; ci = c[i]; i++) {
                        if (!prev(ci) && !next(ci)) {
                            r[++ri] = ci;
                        }
                    }
                    return r;
                },

                "empty": function(c) {
                    var r = [], ri = -1,
                        i, ci, cns, j, cn, empty;
                    for (i = 0; ci = c[i]; i++) {
                        cns = ci.childNodes;
                        j = 0;
                        empty = true;
                        while (cn = cns[j]) {
                            ++j;
                            if (cn.nodeType == 1 || cn.nodeType == 3) {
                                empty = false;
                                break;
                            }
                        }
                        if (empty) {
                            r[++ri] = ci;
                        }
                    }
                    return r;
                },

                "contains": function(c, v) {
                    var r = [], ri = -1,
                        i, ci;
                    for (i = 0; ci = c[i]; i++) {
                        if ((ci.textContent || ci.innerText || ci.text || '').indexOf(v) != -1) {
                            r[++ri] = ci;
                        }
                    }
                    return r;
                },

                "nodeValue": function(c, v) {
                    var r = [], ri = -1,
                        i, ci;
                    for (i = 0; ci = c[i]; i++) {
                        if (ci.firstChild && ci.firstChild.nodeValue == v) {
                            r[++ri] = ci;
                        }
                    }
                    return r;
                },

                "checked": function(c) {
                    var r = [], ri = -1,
                        i, ci;
                    for (i = 0; ci = c[i]; i++) {
                        if (ci.checked == true) {
                            r[++ri] = ci;
                        }
                    }
                    return r;
                },

                "not": function(c, ss) {
                    return DQ.filter(c, ss, true);
                },

                "any": function(c, selectors) {
                    var ss = selectors.split('|'),
                        r = [], ri = -1, s,
                        i, ci, j;
                    for (i = 0; ci = c[i]; i++) {
                        for (j = 0; s = ss[j]; j++) {
                            if (DQ.is(ci, s)) {
                                r[++ri] = ci;
                                break;
                            }
                        }
                    }
                    return r;
                },

                "odd": function(c) {
                    return this["nth-child"](c, "odd");
                },

                "even": function(c) {
                    return this["nth-child"](c, "even");
                },

                "nth": function(c, a) {
                    return c[a - 1] || [];
                },

                "first": function(c) {
                    return c[0] || [];
                },

                "last": function(c) {
                    return c[c.length - 1] || [];
                },

                "has": function(c, ss) {
                    var s = DQ.select,
                        r = [], ri = -1,
                        i, ci;
                    for (i = 0; ci = c[i]; i++) {
                        if (s(ss, ci).length > 0) {
                            r[++ri] = ci;
                        }
                    }
                    return r;
                },

                "next": function(c, ss) {
                    var is = DQ.is,
                        r = [], ri = -1,
                        i, ci, n;
                    for (i = 0; ci = c[i]; i++) {
                        n = next(ci);
                        if (n && is(n, ss)) {
                            r[++ri] = ci;
                        }
                    }
                    return r;
                },

                "prev": function(c, ss) {
                    var is = DQ.is,
                        r = [], ri = -1,
                        i, ci, n;
                    for (i = 0; ci = c[i]; i++) {
                        n = prev(ci);
                        if (n && is(n, ss)) {
                            r[++ri] = ci;
                        }
                    }
                    return r;
                },

                focusable: function(candidates) {
                    var len = candidates.length,
                        results = [],
                        i = 0,
                        c;

                    for (; i < len; i++) {
                        c = candidates[i];
                        if (Ext.fly(c, '_DomQuery').isFocusable()) {
                            results.push(c);
                        }
                    }

                    return results;
                },

                visible: function(candidates, deep) {
                    var len = candidates.length,
                        results = [],
                        i = 0,
                        c;

                    for (; i < len; i++) {
                        c = candidates[i];
                        if (Ext.fly(c, '_DomQuery').isVisible(deep)) {
                            results.push(c);
                        }
                    }

                    return results;
                }
            }
        };
    }());

    /**
    * Shorthand of {@link Ext.dom.Query#select}
    * @member Ext
    * @method query
    * @inheritdoc Ext.dom.Query#select
    */
    Ext.query = Ext.DomQuery.select;