    /**
     * This class encapsulates a *collection* of DOM elements, providing methods to filter members, or to perform collective
     * actions upon the whole set.
     *
     * Although they are not listed, this class supports all of the methods of {@link Ext.dom.Element} and
     * {@link Ext.fx.Anim}. The methods from these classes will be performed on all the elements in this collection.
     *
     * Example:
     *
     *     var els = Ext.select("#some-el div.some-class");
     *     // or select directly from an existing element
     *     var el = Ext.get('some-el');
     *     el.select('div.some-class');
     *
     *     els.setWidth(100); // all elements become 100 width
     *     els.hide(true); // all elements fade out and hide
     *     // or
     *     els.setWidth(100).hide(true);
     */
    Ext.define('Ext.dom.CompositeElementLite', {
        alternateClassName: 'Ext.CompositeElementLite',

        requires: ['Ext.dom.Element'],

        statics: {
            /**
             * @private
             * Copies all of the functions from Ext.dom.Element's prototype onto CompositeElementLite's prototype.
             * This is called twice - once immediately below, and once again after additional Ext.dom.Element
             * are added in Ext JS
             */
            importElementMethods: function() {
                var name,
                    elementPrototype = Ext.dom.Element.prototype,
                    prototype = this.prototype;

                for (name in elementPrototype) {
                    if (typeof elementPrototype[name] == 'function'){
                        (function(key) {
                            prototype[key] = prototype[key] || function() {
                                return this.invoke(key, arguments);
                            };
                        }).call(prototype, name);

                    }
                }
            }
        },

        constructor: function(elements, root) {
            /**
             * @property {HTMLElement[]} elements
             * The Array of DOM elements which this CompositeElement encapsulates.
             *
             * This will not *usually* be accessed in developers' code, but developers wishing to augment the capabilities
             * of the CompositeElementLite class may use it when adding methods to the class.
             *
             * For example to add the `nextAll` method to the class to **add** all following siblings of selected elements,
             * the code would be
             *
             *     Ext.override(Ext.dom.CompositeElementLite, {
             *         nextAll: function() {
             *             var elements = this.elements, i, l = elements.length, n, r = [], ri = -1;
             *
             *             // Loop through all elements in this Composite, accumulating
             *             // an Array of all siblings.
             *             for (i = 0; i < l; i++) {
             *                 for (n = elements[i].nextSibling; n; n = n.nextSibling) {
             *                     r[++ri] = n;
             *                 }
             *             }
             *
             *             // Add all found siblings to this Composite
             *             return this.add(r);
             *         }
             *     });
             *
             * @readonly
             */
            this.elements = [];
            this.add(elements, root);
            this.el = new Ext.dom.AbstractElement.Fly();
        },

        /**
         * @property {Boolean} isComposite
         * `true` in this class to identify an object as an instantiated CompositeElement, or subclass thereof.
         */
        isComposite: true,

        // private
        getElement: function(el) {
            // Set the shared flyweight dom property to the current element
            return this.el.attach(el);
        },

        // private
        transformElement: function(el) {
            return Ext.getDom(el);
        },

        /**
         * Returns the number of elements in this Composite.
         * @return {Number}
         */
        getCount: function() {
            return this.elements.length;
        },

        /**
         * Adds elements to this Composite object.
         * @param {HTMLElement[]/Ext.dom.CompositeElement} els Either an Array of DOM elements to add, or another Composite
         * object who's elements should be added.
         * @return {Ext.dom.CompositeElement} This Composite object.
         */
        add: function(els, root) {
            var elements = this.elements,
                i, ln;

            if (!els) {
                return this;
            }

            if (typeof els == "string") {
                els = Ext.dom.Element.selectorFunction(els, root);
            }
            else if (els.isComposite) {
                els = els.elements;
            }
            else if (!Ext.isIterable(els)) {
                els = [els];
            }

            for (i = 0, ln = els.length; i < ln; ++i) {
                elements.push(this.transformElement(els[i]));
            }

            return this;
        },

        invoke: function(fn, args) {
            var elements = this.elements,
                ln = elements.length,
                element,
                i;

            fn = Ext.dom.Element.prototype[fn];
            for (i = 0; i < ln; i++) {
                element = elements[i];

                if (element) {
                    fn.apply(this.getElement(element), args);
                }
            }
            return this;
        },

        /**
         * Returns a flyweight Element of the dom element object at the specified index
         * @param {Number} index
         * @return {Ext.dom.Element}
         */
        item: function(index) {
            var el = this.elements[index],
                out = null;

            if (el) {
                out = this.getElement(el);
            }

            return out;
        },

        // fixes scope with flyweight
        addListener: function(eventName, handler, scope, opt) {
            var els = this.elements,
                    len = els.length,
                    i, e;

            for (i = 0; i < len; i++) {
                e = els[i];
                if (e) {
                    Ext.EventManager.on(e, eventName, handler, scope || e, opt);
                }
            }
            return this;
        },
        /**
         * Calls the passed function for each element in this composite.
         * @param {Function} fn The function to call.
         * @param {Ext.dom.Element} fn.el The current Element in the iteration. **This is the flyweight
         * (shared) Ext.dom.Element instance, so if you require a a reference to the dom node, use el.dom.**
         * @param {Ext.dom.CompositeElement} fn.c This Composite object.
         * @param {Number} fn.index The zero-based index in the iteration.
         * @param {Object} [scope] The scope (this reference) in which the function is executed.
         * Defaults to the Element.
         * @return {Ext.dom.CompositeElement} this
         */
        each: function(fn, scope) {
            var me  = this,
                els = me.elements,
                len = els.length,
                i, e;

            for (i = 0; i < len; i++) {
                e = els[i];
                if (e) {
                    e = this.getElement(e);
                    if (fn.call(scope || e, e, me, i) === false) {
                        break;
                    }
                }
            }
            return me;
        },

        /**
         * Clears this Composite and adds the elements passed.
         * @param {HTMLElement[]/Ext.dom.CompositeElement} els Either an array of DOM elements, or another Composite from which
         * to fill this Composite.
         * @return {Ext.dom.CompositeElement} this
         */
        fill: function(els) {
            var me = this;
            me.elements = [];
            me.add(els);
            return me;
        },

        /**
         * Filters this composite to only elements that match the passed selector.
         * @param {String/Function} selector A string CSS selector or a comparison function. The comparison function will be
         * called with the following arguments:
         * @param {Ext.dom.Element} selector.el The current DOM element.
         * @param {Number} selector.index The current index within the collection.
         * @return {Ext.dom.CompositeElement} this
         */
        filter: function(selector) {
            var me  = this,
                els = me.elements,
                len = els.length,
                out = [],
                i = 0,
                isFunc = typeof selector == 'function',
                add,
                el;

            for (; i < len; i++) {
                el = els[i];
                add = false;
                if (el) {
                    el = me.getElement(el);

                    if (isFunc) {
                        add = selector.call(el, el, me, i) !== false;
                    } else {
                        add = el.is(selector);
                    }

                    if (add) {
                        out.push(me.transformElement(el));
                    }
                }
            }

            me.elements = out;
            return me;
        },

        /**
         * Find the index of the passed element within the composite collection.
         * @param {String/HTMLElement/Ext.Element/Number} el The id of an element, or an Ext.dom.Element, or an HtmlElement
         * to find within the composite collection.
         * @return {Number} The index of the passed Ext.dom.Element in the composite collection, or -1 if not found.
         */
        indexOf: function(el) {
            return Ext.Array.indexOf(this.elements, this.transformElement(el));
        },

        /**
         * Replaces the specified element with the passed element.
         * @param {String/HTMLElement/Ext.Element/Number} el The id of an element, the Element itself, the index of the
         * element in this composite to replace.
         * @param {String/Ext.Element} replacement The id of an element or the Element itself.
         * @param {Boolean} [domReplace] True to remove and replace the element in the document too.
         * @return {Ext.dom.CompositeElement} this
         */
        replaceElement: function(el, replacement, domReplace) {
            var index = !isNaN(el) ? el : this.indexOf(el),
                    d;
            if (index > -1) {
                replacement = Ext.getDom(replacement);
                if (domReplace) {
                    d = this.elements[index];
                    d.parentNode.insertBefore(replacement, d);
                    Ext.removeNode(d);
                }
                Ext.Array.splice(this.elements, index, 1, replacement);
            }
            return this;
        },

        /**
         * Removes all elements.
         */
        clear: function() {
            this.elements = [];
        },

        addElements: function(els, root) {
            if (!els) {
                return this;
            }

            if (typeof els == "string") {
                els = Ext.dom.Element.selectorFunction(els, root);
            }

            var yels = this.elements,
                eLen = els.length,
                e;

            for (e = 0; e < eLen; e++) {
                yels.push(Ext.get(els[e]));
            }

            return this;
        },

        /**
         * Returns the first Element
         * @return {Ext.dom.Element}
         */
        first: function() {
            return this.item(0);
        },

        /**
         * Returns the last Element
         * @return {Ext.dom.Element}
         */
        last: function() {
            return this.item(this.getCount() - 1);
        },

        /**
         * Returns true if this composite contains the passed element
         * @param {String/HTMLElement/Ext.Element/Number} el The id of an element, or an Ext.Element, or an HtmlElement to
         * find within the composite collection.
         * @return {Boolean}
         */
        contains: function(el) {
            return this.indexOf(el) != -1;
        },

        /**
         * Removes the specified element(s).
         * @param {String/HTMLElement/Ext.Element/Number} el The id of an element, the Element itself, the index of the
         * element in this composite or an array of any of those.
         * @param {Boolean} [removeDom] True to also remove the element from the document
         * @return {Ext.dom.CompositeElement} this
         */
        removeElement: function(keys, removeDom) {
            keys = [].concat(keys);

            var me       = this,
                elements = me.elements,
                kLen     = keys.length,
                val, el, k;

            for (k = 0; k < kLen; k++) {
                val = keys[k];

                if ((el = (elements[val] || elements[val = me.indexOf(val)]))) {
                    if (removeDom) {
                        if (el.dom) {
                            el.remove();
                        } else {
                            Ext.removeNode(el);
                        }
                    }
                    Ext.Array.erase(elements, val, 1);
                }
            }

            return me;
        }

    }, function() {
        this.importElementMethods();

        this.prototype.on = this.prototype.addListener;

        if (Ext.DomQuery){
            Ext.dom.Element.selectorFunction = Ext.DomQuery.select;
        }

        /**
         * Selects elements based on the passed CSS selector to enable {@link Ext.Element Element} methods
         * to be applied to many related elements in one statement through the returned
         * {@link Ext.dom.CompositeElement CompositeElement} or
         * {@link Ext.dom.CompositeElementLite CompositeElementLite} object.
         * @param {String/HTMLElement[]} selector The CSS selector or an array of elements
         * @param {HTMLElement/String} [root] The root element of the query or id of the root
         * @return {Ext.dom.CompositeElementLite/Ext.dom.CompositeElement}
         * @member Ext.dom.Element
         * @method select
         * @static
         * @ignore
         */
       Ext.dom.Element.select = function(selector, root) {
            var elements;

            if (typeof selector == "string") {
                elements = Ext.dom.Element.selectorFunction(selector, root);
            }
            else if (selector.length !== undefined) {
                elements = selector;
            }
            else {
                //<debug>
                throw new Error("[Ext.select] Invalid selector specified: " + selector);
                //</debug>
            }

            return new Ext.CompositeElementLite(elements);
        };

        /**
         * @member Ext
         * @method select
         * @inheritdoc Ext.dom.Element#select
         * @ignore
         */
        Ext.select = function() {
            return Ext.dom.Element.select.apply(Ext.dom.Element, arguments);
        };
    });