    /*
     * This is a derivative of the similarly named class in the YUI Library.
     * The original license:
     * Copyright (c) 2006, Yahoo! Inc. All rights reserved.
     * Code licensed under the BSD License:
     * http://developer.yahoo.net/yui/license.txt
     */

    /**
     * @class Ext.dd.DragDropManager
     * DragDropManager is a singleton that tracks the element interaction for
     * all DragDrop items in the window.  Generally, you will not call
     * this class directly, but it does have helper methods that could
     * be useful in your DragDrop implementations.
     * @singleton
     */
    Ext.define('Ext.dd.DragDropManager', {
        singleton: true,

        requires: ['Ext.util.Region'],

        uses: ['Ext.tip.QuickTipManager'],

        // shorter ClassName, to save bytes and use internally
        alternateClassName: ['Ext.dd.DragDropMgr', 'Ext.dd.DDM'],

        /**
         * Two dimensional Array of registered DragDrop objects.  The first
         * dimension is the DragDrop item group, the second the DragDrop
         * object.
         * @property ids
         * @type String[]
         * @private
         * @static
         */
        ids: {},

        /**
         * Array of element ids defined as drag handles.  Used to determine
         * if the element that generated the mousedown event is actually the
         * handle and not the html element itself.
         * @property handleIds
         * @type String[]
         * @private
         * @static
         */
        handleIds: {},

        /**
         * the DragDrop object that is currently being dragged
         * @property dragCurrent
         * @type DragDrop
         * @private
         * @static
         **/
        dragCurrent: null,

        /**
         * the DragDrop object(s) that are being hovered over
         * @property dragOvers
         * @type Array
         * @private
         * @static
         */
        dragOvers: {},

        /**
         * the X distance between the cursor and the object being dragged
         * @property deltaX
         * @type int
         * @private
         * @static
         */
        deltaX: 0,

        /**
         * the Y distance between the cursor and the object being dragged
         * @property deltaY
         * @type int
         * @private
         * @static
         */
        deltaY: 0,

        /**
         * Flag to determine if we should prevent the default behavior of the
         * events we define. By default this is true, but this can be set to
         * false if you need the default behavior (not recommended)
         * @property preventDefault
         * @type boolean
         * @static
         */
        preventDefault: true,

        /**
         * Flag to determine if we should stop the propagation of the events
         * we generate. This is true by default but you may want to set it to
         * false if the html element contains other features that require the
         * mouse click.
         * @property stopPropagation
         * @type boolean
         * @static
         */
        stopPropagation: true,

        /**
         * Internal flag that is set to true when drag and drop has been
         * intialized
         * @property initialized
         * @private
         * @static
         */
        initialized: false,

        /**
         * All drag and drop can be disabled.
         * @property locked
         * @private
         * @static
         */
        locked: false,

        /**
         * Called the first time an element is registered.
         * @method init
         * @private
         * @static
         */
        init: function() {
            this.initialized = true;
        },

        /**
         * In point mode, drag and drop interaction is defined by the
         * location of the cursor during the drag/drop
         * @property POINT
         * @type int
         * @static
         */
        POINT: 0,

        /**
         * In intersect mode, drag and drop interaction is defined by the
         * overlap of two or more drag and drop objects.
         * @property INTERSECT
         * @type int
         * @static
         */
        INTERSECT: 1,

        /**
         * The current drag and drop mode.  Default: POINT
         * @property mode
         * @type int
         * @static
         */
        mode: 0,

        /**
         * Runs method on all drag and drop objects
         * @method _execOnAll
         * @private
         * @static
         */
        _execOnAll: function(sMethod, args) {
            for (var i in this.ids) {
                for (var j in this.ids[i]) {
                    var oDD = this.ids[i][j];
                    if (! this.isTypeOfDD(oDD)) {
                        continue;
                    }
                    oDD[sMethod].apply(oDD, args);
                }
            }
        },

        /**
         * Drag and drop initialization.  Sets up the global event handlers
         * @method _onLoad
         * @private
         * @static
         */
        _onLoad: function() {

            this.init();

            var Event = Ext.EventManager;
            Event.on(document, "mouseup",   this.handleMouseUp, this, true);
            Event.on(document, "mousemove", this.handleMouseMove, this, true);
            Event.on(window,   "unload",    this._onUnload, this, true);
            Event.on(window,   "resize",    this._onResize, this, true);
            // Event.on(window,   "mouseout",    this._test);

        },

        /**
         * Reset constraints on all drag and drop objs
         * @method _onResize
         * @private
         * @static
         */
        _onResize: function(e) {
            this._execOnAll("resetConstraints", []);
        },

        /**
         * Lock all drag and drop functionality
         * @method lock
         * @static
         */
        lock: function() { this.locked = true; },

        /**
         * Unlock all drag and drop functionality
         * @method unlock
         * @static
         */
        unlock: function() { this.locked = false; },

        /**
         * Is drag and drop locked?
         * @method isLocked
         * @return {boolean} True if drag and drop is locked, false otherwise.
         * @static
         */
        isLocked: function() { return this.locked; },

        /**
         * Location cache that is set for all drag drop objects when a drag is
         * initiated, cleared when the drag is finished.
         * @property locationCache
         * @private
         * @static
         */
        locationCache: {},

        /**
         * Set useCache to false if you want to force object the lookup of each
         * drag and drop linked element constantly during a drag.
         * @property useCache
         * @type boolean
         * @static
         */
        useCache: true,

        /**
         * The number of pixels that the mouse needs to move after the
         * mousedown before the drag is initiated.  Default=3;
         * @property clickPixelThresh
         * @type int
         * @static
         */
        clickPixelThresh: 3,

        /**
         * The number of milliseconds after the mousedown event to initiate the
         * drag if we don't get a mouseup event. Default=350
         * @property clickTimeThresh
         * @type int
         * @static
         */
        clickTimeThresh: 350,

        /**
         * Flag that indicates that either the drag pixel threshold or the
         * mousdown time threshold has been met
         * @property dragThreshMet
         * @type boolean
         * @private
         * @static
         */
        dragThreshMet: false,

        /**
         * Timeout used for the click time threshold
         * @property clickTimeout
         * @type Object
         * @private
         * @static
         */
        clickTimeout: null,

        /**
         * The X position of the mousedown event stored for later use when a
         * drag threshold is met.
         * @property startX
         * @type int
         * @private
         * @static
         */
        startX: 0,

        /**
         * The Y position of the mousedown event stored for later use when a
         * drag threshold is met.
         * @property startY
         * @type int
         * @private
         * @static
         */
        startY: 0,

        /**
         * Each DragDrop instance must be registered with the DragDropManager.
         * This is executed in DragDrop.init()
         * @method regDragDrop
         * @param {DragDrop} oDD the DragDrop object to register
         * @param {String} sGroup the name of the group this element belongs to
         * @static
         */
        regDragDrop: function(oDD, sGroup) {
            if (!this.initialized) { this.init(); }

            if (!this.ids[sGroup]) {
                this.ids[sGroup] = {};
            }
            this.ids[sGroup][oDD.id] = oDD;
        },

        /**
         * Removes the supplied dd instance from the supplied group. Executed
         * by DragDrop.removeFromGroup, so don't call this function directly.
         * @method removeDDFromGroup
         * @private
         * @static
         */
        removeDDFromGroup: function(oDD, sGroup) {
            if (!this.ids[sGroup]) {
                this.ids[sGroup] = {};
            }

            var obj = this.ids[sGroup];
            if (obj && obj[oDD.id]) {
                delete obj[oDD.id];
            }
        },

        /**
         * Unregisters a drag and drop item.  This is executed in
         * DragDrop.unreg, use that method instead of calling this directly.
         * @method _remove
         * @private
         * @static
         */
        _remove: function(oDD) {
            for (var g in oDD.groups) {
                if (g && this.ids[g] && this.ids[g][oDD.id]) {
                    delete this.ids[g][oDD.id];
                }
            }
            delete this.handleIds[oDD.id];
        },

        /**
         * Each DragDrop handle element must be registered.  This is done
         * automatically when executing DragDrop.setHandleElId()
         * @method regHandle
         * @param {String} sDDId the DragDrop id this element is a handle for
         * @param {String} sHandleId the id of the element that is the drag
         * handle
         * @static
         */
        regHandle: function(sDDId, sHandleId) {
            if (!this.handleIds[sDDId]) {
                this.handleIds[sDDId] = {};
            }
            this.handleIds[sDDId][sHandleId] = sHandleId;
        },

        /**
         * Utility function to determine if a given element has been
         * registered as a drag drop item.
         * @method isDragDrop
         * @param {String} id the element id to check
         * @return {boolean} true if this element is a DragDrop item,
         * false otherwise
         * @static
         */
        isDragDrop: function(id) {
            return ( this.getDDById(id) ) ? true : false;
        },

        /**
         * Returns the drag and drop instances that are in all groups the
         * passed in instance belongs to.
         * @method getRelated
         * @param {DragDrop} p_oDD the obj to get related data for
         * @param {boolean} bTargetsOnly if true, only return targetable objs
         * @return {DragDrop[]} the related instances
         * @static
         */
        getRelated: function(p_oDD, bTargetsOnly) {
            var oDDs = [];
            for (var i in p_oDD.groups) {
                for (var j in this.ids[i]) {
                    var dd = this.ids[i][j];
                    if (! this.isTypeOfDD(dd)) {
                        continue;
                    }
                    if (!bTargetsOnly || dd.isTarget) {
                        oDDs[oDDs.length] = dd;
                    }
                }
            }

            return oDDs;
        },

        /**
         * Returns true if the specified dd target is a legal target for
         * the specifice drag obj
         * @method isLegalTarget
         * @param {DragDrop} oDD the drag obj
         * @param {DragDrop} oTargetDD the target
         * @return {boolean} true if the target is a legal target for the
         * dd obj
         * @static
         */
        isLegalTarget: function (oDD, oTargetDD) {
            var targets = this.getRelated(oDD, true);
            for (var i=0, len=targets.length;i<len;++i) {
                if (targets[i].id == oTargetDD.id) {
                    return true;
                }
            }

            return false;
        },

        /**
         * My goal is to be able to transparently determine if an object is
         * typeof DragDrop, and the exact subclass of DragDrop.  typeof
         * returns "object", oDD.constructor.toString() always returns
         * "DragDrop" and not the name of the subclass.  So for now it just
         * evaluates a well-known variable in DragDrop.
         * @method isTypeOfDD
         * @param {Object} the object to evaluate
         * @return {boolean} true if typeof oDD = DragDrop
         * @static
         */
        isTypeOfDD: function (oDD) {
            return (oDD && oDD.__ygDragDrop);
        },

        /**
         * Utility function to determine if a given element has been
         * registered as a drag drop handle for the given Drag Drop object.
         * @method isHandle
         * @param {String} id the element id to check
         * @return {boolean} true if this element is a DragDrop handle, false
         * otherwise
         * @static
         */
        isHandle: function(sDDId, sHandleId) {
            return ( this.handleIds[sDDId] &&
                            this.handleIds[sDDId][sHandleId] );
        },

        /**
         * Returns the DragDrop instance for a given id
         * @method getDDById
         * @param {String} id the id of the DragDrop object
         * @return {DragDrop} the drag drop object, null if it is not found
         * @static
         */
        getDDById: function(id) {
            for (var i in this.ids) {
                if (this.ids[i][id]) {
                    return this.ids[i][id];
                }
            }
            return null;
        },

        /**
         * Fired after a registered DragDrop object gets the mousedown event.
         * Sets up the events required to track the object being dragged
         * @method handleMouseDown
         * @param {Event} e the event
         * @param oDD the DragDrop object being dragged
         * @private
         * @static
         */
        handleMouseDown: function(e, oDD) {
            if(Ext.tip.QuickTipManager){
                Ext.tip.QuickTipManager.ddDisable();
            }
            if(this.dragCurrent){
                // the original browser mouseup wasn't handled (e.g. outside FF browser window)
                // so clean up first to avoid breaking the next drag
                this.handleMouseUp(e);
            }

            this.currentTarget = e.getTarget();
            this.dragCurrent = oDD;

            var el = oDD.getEl();

            // track start position
            this.startX = e.getPageX();
            this.startY = e.getPageY();

            this.deltaX = this.startX - el.offsetLeft;
            this.deltaY = this.startY - el.offsetTop;

            this.dragThreshMet = false;

            this.clickTimeout = setTimeout(
                    function() {
                        var DDM = Ext.dd.DragDropManager;
                        DDM.startDrag(DDM.startX, DDM.startY);
                    },
                    this.clickTimeThresh );
        },

        /**
         * Fired when either the drag pixel threshol or the mousedown hold
         * time threshold has been met.
         * @method startDrag
         * @param x {int} the X position of the original mousedown
         * @param y {int} the Y position of the original mousedown
         * @static
         */
        startDrag: function(x, y) {
            clearTimeout(this.clickTimeout);
            if (this.dragCurrent) {
                this.dragCurrent.b4StartDrag(x, y);
                this.dragCurrent.startDrag(x, y);
            }
            this.dragThreshMet = true;
        },

        /**
         * Internal function to handle the mouseup event.  Will be invoked
         * from the context of the document.
         * @method handleMouseUp
         * @param {Event} e the event
         * @private
         * @static
         */
        handleMouseUp: function(e) {

            if(Ext.tip.QuickTipManager){
                Ext.tip.QuickTipManager.ddEnable();
            }
            if (! this.dragCurrent) {
                return;
            }

            clearTimeout(this.clickTimeout);

            if (this.dragThreshMet) {
                this.fireEvents(e, true);
            } else {
            }

            this.stopDrag(e);

            this.stopEvent(e);
        },

        /**
         * Utility to stop event propagation and event default, if these
         * features are turned on.
         * @method stopEvent
         * @param {Event} e the event as returned by this.getEvent()
         * @static
         */
        stopEvent: function(e){
            if(this.stopPropagation) {
                e.stopPropagation();
            }

            if (this.preventDefault) {
                e.preventDefault();
            }
        },

        /**
         * Internal function to clean up event handlers after the drag
         * operation is complete
         * @method stopDrag
         * @param {Event} e the event
         * @private
         * @static
         */
        stopDrag: function(e) {
            // Fire the drag end event for the item that was dragged
            if (this.dragCurrent) {
                if (this.dragThreshMet) {
                    this.dragCurrent.b4EndDrag(e);
                    this.dragCurrent.endDrag(e);
                }

                this.dragCurrent.onMouseUp(e);
            }

            this.dragCurrent = null;
            this.dragOvers = {};
        },

        /**
         * Internal function to handle the mousemove event.  Will be invoked
         * from the context of the html element.
         *
         * @TODO figure out what we can do about mouse events lost when the
         * user drags objects beyond the window boundary.  Currently we can
         * detect this in internet explorer by verifying that the mouse is
         * down during the mousemove event.  Firefox doesn't give us the
         * button state on the mousemove event.
         * @method handleMouseMove
         * @param {Event} e the event
         * @private
         * @static
         */
        handleMouseMove: function(e) {
            if (! this.dragCurrent) {
                return true;
            }
            // var button = e.which || e.button;

            // check for IE mouseup outside of page boundary
            if (Ext.isIE && (e.button !== 0 && e.button !== 1 && e.button !== 2)) {
                this.stopEvent(e);
                return this.handleMouseUp(e);
            }

            if (!this.dragThreshMet) {
                var diffX = Math.abs(this.startX - e.getPageX());
                var diffY = Math.abs(this.startY - e.getPageY());
                if (diffX > this.clickPixelThresh ||
                            diffY > this.clickPixelThresh) {
                    this.startDrag(this.startX, this.startY);
                }
            }

            if (this.dragThreshMet) {
                this.dragCurrent.b4Drag(e);
                this.dragCurrent.onDrag(e);
                if(!this.dragCurrent.moveOnly){
                    this.fireEvents(e, false);
                }
            }

            this.stopEvent(e);

            return true;
        },

        /**
         * Iterates over all of the DragDrop elements to find ones we are
         * hovering over or dropping on
         * @method fireEvents
         * @param {Event} e the event
         * @param {boolean} isDrop is this a drop op or a mouseover op?
         * @private
         * @static
         */
        fireEvents: function(e, isDrop) {
            var dc = this.dragCurrent;

            // If the user did the mouse up outside of the window, we could
            // get here even though we have ended the drag.
            if (!dc || dc.isLocked()) {
                return;
            }

            var pt = e.getPoint();

            // cache the previous dragOver array
            var oldOvers = [];

            var outEvts   = [];
            var overEvts  = [];
            var dropEvts  = [];
            var enterEvts = [];

            // Check to see if the object(s) we were hovering over is no longer
            // being hovered over so we can fire the onDragOut event
            for (var i in this.dragOvers) {

                var ddo = this.dragOvers[i];

                if (! this.isTypeOfDD(ddo)) {
                    continue;
                }

                if (! this.isOverTarget(pt, ddo, this.mode)) {
                    outEvts.push( ddo );
                }

                oldOvers[i] = true;
                delete this.dragOvers[i];
            }

            for (var sGroup in dc.groups) {

                if ("string" != typeof sGroup) {
                    continue;
                }

                for (i in this.ids[sGroup]) {
                    var oDD = this.ids[sGroup][i];
                    if (! this.isTypeOfDD(oDD)) {
                        continue;
                    }

                    if (oDD.isTarget && !oDD.isLocked() && ((oDD != dc) || (dc.ignoreSelf === false))) {
                        if (this.isOverTarget(pt, oDD, this.mode)) {
                            // look for drop interactions
                            if (isDrop) {
                                dropEvts.push( oDD );
                            // look for drag enter and drag over interactions
                            } else {

                                // initial drag over: dragEnter fires
                                if (!oldOvers[oDD.id]) {
                                    enterEvts.push( oDD );
                                // subsequent drag overs: dragOver fires
                                } else {
                                    overEvts.push( oDD );
                                }

                                this.dragOvers[oDD.id] = oDD;
                            }
                        }
                    }
                }
            }

            if (this.mode) {
                if (outEvts.length) {
                    dc.b4DragOut(e, outEvts);
                    dc.onDragOut(e, outEvts);
                }

                if (enterEvts.length) {
                    dc.onDragEnter(e, enterEvts);
                }

                if (overEvts.length) {
                    dc.b4DragOver(e, overEvts);
                    dc.onDragOver(e, overEvts);
                }

                if (dropEvts.length) {
                    dc.b4DragDrop(e, dropEvts);
                    dc.onDragDrop(e, dropEvts);
                }

            } else {
                // fire dragout events
                var len = 0;
                for (i=0, len=outEvts.length; i<len; ++i) {
                    dc.b4DragOut(e, outEvts[i].id);
                    dc.onDragOut(e, outEvts[i].id);
                }

                // fire enter events
                for (i=0,len=enterEvts.length; i<len; ++i) {
                    // dc.b4DragEnter(e, oDD.id);
                    dc.onDragEnter(e, enterEvts[i].id);
                }

                // fire over events
                for (i=0,len=overEvts.length; i<len; ++i) {
                    dc.b4DragOver(e, overEvts[i].id);
                    dc.onDragOver(e, overEvts[i].id);
                }

                // fire drop events
                for (i=0, len=dropEvts.length; i<len; ++i) {
                    dc.b4DragDrop(e, dropEvts[i].id);
                    dc.onDragDrop(e, dropEvts[i].id);
                }

            }

            // notify about a drop that did not find a target
            if (isDrop && !dropEvts.length) {
                dc.onInvalidDrop(e);
            }

        },

        /**
         * Helper function for getting the best match from the list of drag
         * and drop objects returned by the drag and drop events when we are
         * in INTERSECT mode.  It returns either the first object that the
         * cursor is over, or the object that has the greatest overlap with
         * the dragged element.
         * @method getBestMatch
         * @param  {DragDrop[]} dds The array of drag and drop objects
         * targeted
         * @return {DragDrop}       The best single match
         * @static
         */
        getBestMatch: function(dds) {
            var winner = null;
            // Return null if the input is not what we expect
            //if (!dds || !dds.length || dds.length == 0) {
               // winner = null;
            // If there is only one item, it wins
            //} else if (dds.length == 1) {

            var len = dds.length;

            if (len == 1) {
                winner = dds[0];
            } else {
                // Loop through the targeted items
                for (var i=0; i<len; ++i) {
                    var dd = dds[i];
                    // If the cursor is over the object, it wins.  If the
                    // cursor is over multiple matches, the first one we come
                    // to wins.
                    if (dd.cursorIsOver) {
                        winner = dd;
                        break;
                    // Otherwise the object with the most overlap wins
                    } else {
                        if (!winner ||
                            winner.overlap.getArea() < dd.overlap.getArea()) {
                            winner = dd;
                        }
                    }
                }
            }

            return winner;
        },

        /**
         * Refreshes the cache of the top-left and bottom-right points of the
         * drag and drop objects in the specified group(s).  This is in the
         * format that is stored in the drag and drop instance, so typical
         * usage is:
         * <code>
         * Ext.dd.DragDropManager.refreshCache(ddinstance.groups);
         * </code>
         * Alternatively:
         * <code>
         * Ext.dd.DragDropManager.refreshCache({group1:true, group2:true});
         * </code>
         * @TODO this really should be an indexed array.  Alternatively this
         * method could accept both.
         * @method refreshCache
         * @param {Object} groups an associative array of groups to refresh
         * @static
         */
        refreshCache: function(groups) {
            for (var sGroup in groups) {
                if ("string" != typeof sGroup) {
                    continue;
                }
                for (var i in this.ids[sGroup]) {
                    var oDD = this.ids[sGroup][i];

                    if (this.isTypeOfDD(oDD)) {
                    // if (this.isTypeOfDD(oDD) && oDD.isTarget) {
                        var loc = this.getLocation(oDD);
                        if (loc) {
                            this.locationCache[oDD.id] = loc;
                        } else {
                            delete this.locationCache[oDD.id];
                            // this will unregister the drag and drop object if
                            // the element is not in a usable state
                            // oDD.unreg();
                        }
                    }
                }
            }
        },

        /**
         * This checks to make sure an element exists and is in the DOM.  The
         * main purpose is to handle cases where innerHTML is used to remove
         * drag and drop objects from the DOM.  IE provides an 'unspecified
         * error' when trying to access the offsetParent of such an element
         * @method verifyEl
         * @param {HTMLElement} el the element to check
         * @return {boolean} true if the element looks usable
         * @static
         */
        verifyEl: function(el) {
            if (el) {
                var parent;
                if(Ext.isIE){
                    try{
                        parent = el.offsetParent;
                    }catch(e){}
                }else{
                    parent = el.offsetParent;
                }
                if (parent) {
                    return true;
                }
            }

            return false;
        },

        /**
         * Returns a Region object containing the drag and drop element's position
         * and size, including the padding configured for it
         * @method getLocation
         * @param {DragDrop} oDD the drag and drop object to get the
         *                       location for
         * @return {Ext.util.Region} a Region object representing the total area
         *                             the element occupies, including any padding
         *                             the instance is configured for.
         * @static
         */
        getLocation: function(oDD) {
            if (! this.isTypeOfDD(oDD)) {
                return null;
            }

            //delegate getLocation method to the
            //drag and drop target.
            if (oDD.getRegion) {
                return oDD.getRegion();
            }

            var el = oDD.getEl(), pos, x1, x2, y1, y2, t, r, b, l;

            try {
                pos= Ext.core.Element.getXY(el);
            } catch (e) { }

            if (!pos) {
                return null;
            }

            x1 = pos[0];
            x2 = x1 + el.offsetWidth;
            y1 = pos[1];
            y2 = y1 + el.offsetHeight;

            t = y1 - oDD.padding[0];
            r = x2 + oDD.padding[1];
            b = y2 + oDD.padding[2];
            l = x1 - oDD.padding[3];

            return Ext.create('Ext.util.Region', t, r, b, l);
        },

        /**
         * Checks the cursor location to see if it over the target
         * @method isOverTarget
         * @param {Ext.util.Point} pt The point to evaluate
         * @param {DragDrop} oTarget the DragDrop object we are inspecting
         * @return {boolean} true if the mouse is over the target
         * @private
         * @static
         */
        isOverTarget: function(pt, oTarget, intersect) {
            // use cache if available
            var loc = this.locationCache[oTarget.id];
            if (!loc || !this.useCache) {
                loc = this.getLocation(oTarget);
                this.locationCache[oTarget.id] = loc;

            }

            if (!loc) {
                return false;
            }

            oTarget.cursorIsOver = loc.contains( pt );

            // DragDrop is using this as a sanity check for the initial mousedown
            // in this case we are done.  In POINT mode, if the drag obj has no
            // contraints, we are also done. Otherwise we need to evaluate the
            // location of the target as related to the actual location of the
            // dragged element.
            var dc = this.dragCurrent;
            if (!dc || !dc.getTargetCoord ||
                    (!intersect && !dc.constrainX && !dc.constrainY)) {
                return oTarget.cursorIsOver;
            }

            oTarget.overlap = null;

            // Get the current location of the drag element, this is the
            // location of the mouse event less the delta that represents
            // where the original mousedown happened on the element.  We
            // need to consider constraints and ticks as well.
            var pos = dc.getTargetCoord(pt.x, pt.y);

            var el = dc.getDragEl();
            var curRegion = Ext.create('Ext.util.Region', pos.y,
                                                   pos.x + el.offsetWidth,
                                                   pos.y + el.offsetHeight,
                                                   pos.x );

            var overlap = curRegion.intersect(loc);

            if (overlap) {
                oTarget.overlap = overlap;
                return (intersect) ? true : oTarget.cursorIsOver;
            } else {
                return false;
            }
        },

        /**
         * unload event handler
         * @method _onUnload
         * @private
         * @static
         */
        _onUnload: function(e, me) {
            Ext.dd.DragDropManager.unregAll();
        },

        /**
         * Cleans up the drag and drop events and objects.
         * @method unregAll
         * @private
         * @static
         */
        unregAll: function() {

            if (this.dragCurrent) {
                this.stopDrag();
                this.dragCurrent = null;
            }

            this._execOnAll("unreg", []);

            for (var i in this.elementCache) {
                delete this.elementCache[i];
            }

            this.elementCache = {};
            this.ids = {};
        },

        /**
         * A cache of DOM elements
         * @property elementCache
         * @private
         * @static
         */
        elementCache: {},

        /**
         * Get the wrapper for the DOM element specified
         * @method getElWrapper
         * @param {String} id the id of the element to get
         * @return {Ext.dd.DDM.ElementWrapper} the wrapped element
         * @private
         * @deprecated This wrapper isn't that useful
         * @static
         */
        getElWrapper: function(id) {
            var oWrapper = this.elementCache[id];
            if (!oWrapper || !oWrapper.el) {
                oWrapper = this.elementCache[id] =
                    new this.ElementWrapper(Ext.getDom(id));
            }
            return oWrapper;
        },

        /**
         * Returns the actual DOM element
         * @method getElement
         * @param {String} id the id of the elment to get
         * @return {Object} The element
         * @deprecated use Ext.lib.Ext.getDom instead
         * @static
         */
        getElement: function(id) {
            return Ext.getDom(id);
        },

        /**
         * Returns the style property for the DOM element (i.e.,
         * document.getElById(id).style)
         * @method getCss
         * @param {String} id the id of the elment to get
         * @return {Object} The style property of the element
         * @static
         */
        getCss: function(id) {
            var el = Ext.getDom(id);
            return (el) ? el.style : null;
        },

        /**
         * Inner class for cached elements
         * @class Ext.dd.DragDropManager.ElementWrapper
         * @for DragDropManager
         * @private
         * @deprecated
         */
        ElementWrapper: function(el) {
                /**
                 * The element
                 * @property el
                 */
                this.el = el || null;
                /**
                 * The element id
                 * @property id
                 */
                this.id = this.el && el.id;
                /**
                 * A reference to the style property
                 * @property css
                 */
                this.css = this.el && el.style;
            },

        /**
         * Returns the X position of an html element
         * @method getPosX
         * @param el the element for which to get the position
         * @return {int} the X coordinate
         * @for DragDropManager
         * @static
         */
        getPosX: function(el) {
            return Ext.core.Element.getX(el);
        },

        /**
         * Returns the Y position of an html element
         * @method getPosY
         * @param el the element for which to get the position
         * @return {int} the Y coordinate
         * @static
         */
        getPosY: function(el) {
            return Ext.core.Element.getY(el);
        },

        /**
         * Swap two nodes.  In IE, we use the native method, for others we
         * emulate the IE behavior
         * @method swapNode
         * @param n1 the first node to swap
         * @param n2 the other node to swap
         * @static
         */
        swapNode: function(n1, n2) {
            if (n1.swapNode) {
                n1.swapNode(n2);
            } else {
                var p = n2.parentNode;
                var s = n2.nextSibling;

                if (s == n1) {
                    p.insertBefore(n1, n2);
                } else if (n2 == n1.nextSibling) {
                    p.insertBefore(n2, n1);
                } else {
                    n1.parentNode.replaceChild(n2, n1);
                    p.insertBefore(n1, s);
                }
            }
        },

        /**
         * Returns the current scroll position
         * @method getScroll
         * @private
         * @static
         */
        getScroll: function () {
            var doc   = window.document,
                docEl = doc.documentElement,
                body  = doc.body,
                top   = 0,
                left  = 0;

            if (Ext.isGecko4) {
                top  = window.scrollYOffset;
                left = window.scrollXOffset;
            } else {
                if (docEl && (docEl.scrollTop || docEl.scrollLeft)) {
                    top  = docEl.scrollTop;
                    left = docEl.scrollLeft;
                } else if (body) {
                    top  = body.scrollTop;
                    left = body.scrollLeft;
                }
            }
            return {
                top: top,
                left: left
            };
        },

        /**
         * Returns the specified element style property
         * @method getStyle
         * @param {HTMLElement} el          the element
         * @param {string}      styleProp   the style property
         * @return {string} The value of the style property
         * @static
         */
        getStyle: function(el, styleProp) {
            return Ext.fly(el).getStyle(styleProp);
        },

        /**
         * Gets the scrollTop
         * @method getScrollTop
         * @return {int} the document's scrollTop
         * @static
         */
        getScrollTop: function () {
            return this.getScroll().top;
        },

        /**
         * Gets the scrollLeft
         * @method getScrollLeft
         * @return {int} the document's scrollTop
         * @static
         */
        getScrollLeft: function () {
            return this.getScroll().left;
        },

        /**
         * Sets the x/y position of an element to the location of the
         * target element.
         * @method moveToEl
         * @param {HTMLElement} moveEl      The element to move
         * @param {HTMLElement} targetEl    The position reference element
         * @static
         */
        moveToEl: function (moveEl, targetEl) {
            var aCoord = Ext.core.Element.getXY(targetEl);
            Ext.core.Element.setXY(moveEl, aCoord);
        },

        /**
         * Numeric array sort function
         * @method numericSort
         * @static
         */
        numericSort: function(a, b) {
            return (a - b);
        },

        /**
         * Internal counter
         * @property _timeoutCount
         * @private
         * @static
         */
        _timeoutCount: 0,

        /**
         * Trying to make the load order less important.  Without this we get
         * an error if this file is loaded before the Event Utility.
         * @method _addListeners
         * @private
         * @static
         */
        _addListeners: function() {
            if ( document ) {
                this._onLoad();
            } else {
                if (this._timeoutCount > 2000) {
                } else {
                    setTimeout(this._addListeners, 10);
                    if (document && document.body) {
                        this._timeoutCount += 1;
                    }
                }
            }
        },

        /**
         * Recursively searches the immediate parent and all child nodes for
         * the handle element in order to determine wheter or not it was
         * clicked.
         * @method handleWasClicked
         * @param node the html element to inspect
         * @static
         */
        handleWasClicked: function(node, id) {
            if (this.isHandle(id, node.id)) {
                return true;
            } else {
                // check to see if this is a text node child of the one we want
                var p = node.parentNode;

                while (p) {
                    if (this.isHandle(id, p.id)) {
                        return true;
                    } else {
                        p = p.parentNode;
                    }
                }
            }

            return false;
        }
    }, function() {
        this._addListeners();
    });