The source code

    /*
     * These classes are derivatives of the similarly named classes 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
     */

    (function() {

    var Event=Ext.EventManager;
    var Dom=Ext.lib.Dom;

    /**
     * @class Ext.dd.DragDrop
     * Defines the interface and base operation of items that that can be
     * dragged or can be drop targets.  It was designed to be extended, overriding
     * the event handlers for startDrag, onDrag, onDragOver and onDragOut.
     * Up to three html elements can be associated with a DragDrop instance:
     * <ul>
     * <li>linked element: the element that is passed into the constructor.
     * This is the element which defines the boundaries for interaction with
     * other DragDrop objects.</li>
     * <li>handle element(s): The drag operation only occurs if the element that
     * was clicked matches a handle element.  By default this is the linked
     * element, but there are times that you will want only a portion of the
     * linked element to initiate the drag operation, and the setHandleElId()
     * method provides a way to define this.</li>
     * <li>drag element: this represents the element that would be moved along
     * with the cursor during a drag operation.  By default, this is the linked
     * element itself as in {@link Ext.dd.DD}.  setDragElId() lets you define
     * a separate element that would be moved, as in {@link Ext.dd.DDProxy}.
     * </li>
     * </ul>
     * This class should not be instantiated until the onload event to ensure that
     * the associated elements are available.
     * The following would define a DragDrop obj that would interact with any
     * other DragDrop obj in the "group1" group:
     * <pre>
     *  dd = new Ext.dd.DragDrop("div1", "group1");
     * </pre>
     * Since none of the event handlers have been implemented, nothing would
     * actually happen if you were to run the code above.  Normally you would
     * override this class or one of the default implementations, but you can
     * also override the methods you want on an instance of the class...
     * <pre>
     *  dd.onDragDrop = function(e, id) {
     *  &nbsp;&nbsp;alert("dd was dropped on " + id);
     *  }
     * </pre>
     * @constructor
     * @param {String} id of the element that is linked to this instance
     * @param {String} sGroup the group of related DragDrop objects
     * @param {object} config an object containing configurable attributes
     *                Valid properties for DragDrop:
     *                    padding, isTarget, maintainOffset, primaryButtonOnly
     */
    Ext.dd.DragDrop = function(id, sGroup, config) {
        if(id) {
            this.init(id, sGroup, config);
        }
    };

    Ext.dd.DragDrop.prototype = {

        /**
         * Set to false to enable a DragDrop object to fire drag events while dragging
         * over its own Element. Defaults to true - DragDrop objects do not by default
         * fire drag events to themselves.
         * @property ignoreSelf
         * @type Boolean
         */

        /**
         * The id of the element associated with this object.  This is what we
         * refer to as the "linked element" because the size and position of
         * this element is used to determine when the drag and drop objects have
         * interacted.
         * @property id
         * @type String
         */
        id: null,

        /**
         * Configuration attributes passed into the constructor
         * @property config
         * @type object
         */
        config: null,

        /**
         * The id of the element that will be dragged.  By default this is same
         * as the linked element, but could be changed to another element. Ex:
         * Ext.dd.DDProxy
         * @property dragElId
         * @type String
         * @private
         */
        dragElId: null,

        /**
         * The ID of the element that initiates the drag operation.  By default
         * this is the linked element, but could be changed to be a child of this
         * element.  This lets us do things like only starting the drag when the
         * header element within the linked html element is clicked.
         * @property handleElId
         * @type String
         * @private
         */
        handleElId: null,

        /**
         * An object who's property names identify HTML tags to be considered invalid as drag handles.
         * A non-null property value identifies the tag as invalid. Defaults to the
         * following value which prevents drag operations from being initiated by &lt;a> elements:<pre><code>
    {
        A: "A"
    }</code></pre>
         * @property invalidHandleTypes
         * @type Object
         */
        invalidHandleTypes: null,

        /**
         * An object who's property names identify the IDs of elements to be considered invalid as drag handles.
         * A non-null property value identifies the ID as invalid. For example, to prevent
         * dragging from being initiated on element ID "foo", use:<pre><code>
    {
        foo: true
    }</code></pre>
         * @property invalidHandleIds
         * @type Object
         */
        invalidHandleIds: null,

        /**
         * An Array of CSS class names for elements to be considered in valid as drag handles.
         * @property invalidHandleClasses
         * @type Array
         */
        invalidHandleClasses: null,

        /**
         * The linked element's absolute X position at the time the drag was
         * started
         * @property startPageX
         * @type int
         * @private
         */
        startPageX: 0,

        /**
         * The linked element's absolute X position at the time the drag was
         * started
         * @property startPageY
         * @type int
         * @private
         */
        startPageY: 0,

        /**
         * The group defines a logical collection of DragDrop objects that are
         * related.  Instances only get events when interacting with other
         * DragDrop object in the same group.  This lets us define multiple
         * groups using a single DragDrop subclass if we want.
         * @property groups
         * @type object An object in the format {'group1':true, 'group2':true}
         */
        groups: null,

        /**
         * Individual drag/drop instances can be locked.  This will prevent
         * onmousedown start drag.
         * @property locked
         * @type boolean
         * @private
         */
        locked: false,

        /**
         * Lock this instance
         * @method lock
         */
        lock: function() {
            this.locked = true;
        },

        /**
         * When set to true, other DD objects in cooperating DDGroups do not receive
         * notification events when this DD object is dragged over them. Defaults to false.
         * @property moveOnly
         * @type boolean
         */
        moveOnly: false,

        /**
         * Unlock this instace
         * @method unlock
         */
        unlock: function() {
            this.locked = false;
        },

        /**
         * By default, all instances can be a drop target.  This can be disabled by
         * setting isTarget to false.
         * @property isTarget
         * @type boolean
         */
        isTarget: true,

        /**
         * The padding configured for this drag and drop object for calculating
         * the drop zone intersection with this object.
         * @property padding
         * @type int[] An array containing the 4 padding values: [top, right, bottom, left]
         */
        padding: null,

        /**
         * Cached reference to the linked element
         * @property _domRef
         * @private
         */
        _domRef: null,

        /**
         * Internal typeof flag
         * @property __ygDragDrop
         * @private
         */
        __ygDragDrop: true,

        /**
         * Set to true when horizontal contraints are applied
         * @property constrainX
         * @type boolean
         * @private
         */
        constrainX: false,

        /**
         * Set to true when vertical contraints are applied
         * @property constrainY
         * @type boolean
         * @private
         */
        constrainY: false,

        /**
         * The left constraint
         * @property minX
         * @type int
         * @private
         */
        minX: 0,

        /**
         * The right constraint
         * @property maxX
         * @type int
         * @private
         */
        maxX: 0,

        /**
         * The up constraint
         * @property minY
         * @type int
         * @private
         */
        minY: 0,

        /**
         * The down constraint
         * @property maxY
         * @type int
         * @private
         */
        maxY: 0,

        /**
         * Maintain offsets when we resetconstraints.  Set to true when you want
         * the position of the element relative to its parent to stay the same
         * when the page changes
         *
         * @property maintainOffset
         * @type boolean
         */
        maintainOffset: false,

        /**
         * Array of pixel locations the element will snap to if we specified a
         * horizontal graduation/interval.  This array is generated automatically
         * when you define a tick interval.
         * @property xTicks
         * @type int[]
         */
        xTicks: null,

        /**
         * Array of pixel locations the element will snap to if we specified a
         * vertical graduation/interval.  This array is generated automatically
         * when you define a tick interval.
         * @property yTicks
         * @type int[]
         */
        yTicks: null,

        /**
         * By default the drag and drop instance will only respond to the primary
         * button click (left button for a right-handed mouse).  Set to true to
         * allow drag and drop to start with any mouse click that is propogated
         * by the browser
         * @property primaryButtonOnly
         * @type boolean
         */
        primaryButtonOnly: true,

        /**
         * The available property is false until the linked dom element is accessible.
         * @property available
         * @type boolean
         */
        available: false,

        /**
         * By default, drags can only be initiated if the mousedown occurs in the
         * region the linked element is.  This is done in part to work around a
         * bug in some browsers that mis-report the mousedown if the previous
         * mouseup happened outside of the window.  This property is set to true
         * if outer handles are defined.
         *
         * @property hasOuterHandles
         * @type boolean
         * @default false
         */
        hasOuterHandles: false,

        /**
         * Code that executes immediately before the startDrag event
         * @method b4StartDrag
         * @private
         */
        b4StartDrag: function(x, y) { },

        /**
         * Abstract method called after a drag/drop object is clicked
         * and the drag or mousedown time thresholds have beeen met.
         * @method startDrag
         * @param {int} X click location
         * @param {int} Y click location
         */
        startDrag: function(x, y) { /* override this */ },

        /**
         * Code that executes immediately before the onDrag event
         * @method b4Drag
         * @private
         */
        b4Drag: function(e) { },

        /**
         * Abstract method called during the onMouseMove event while dragging an
         * object.
         * @method onDrag
         * @param {Event} e the mousemove event
         */
        onDrag: function(e) { /* override this */ },

        /**
         * Abstract method called when this element fist begins hovering over
         * another DragDrop obj
         * @method onDragEnter
         * @param {Event} e the mousemove event
         * @param {String|DragDrop[]} id In POINT mode, the element
         * id this is hovering over.  In INTERSECT mode, an array of one or more
         * dragdrop items being hovered over.
         */
        onDragEnter: function(e, id) { /* override this */ },

        /**
         * Code that executes immediately before the onDragOver event
         * @method b4DragOver
         * @private
         */
        b4DragOver: function(e) { },

        /**
         * Abstract method called when this element is hovering over another
         * DragDrop obj
         * @method onDragOver
         * @param {Event} e the mousemove event
         * @param {String|DragDrop[]} id In POINT mode, the element
         * id this is hovering over.  In INTERSECT mode, an array of dd items
         * being hovered over.
         */
        onDragOver: function(e, id) { /* override this */ },

        /**
         * Code that executes immediately before the onDragOut event
         * @method b4DragOut
         * @private
         */
        b4DragOut: function(e) { },

        /**
         * Abstract method called when we are no longer hovering over an element
         * @method onDragOut
         * @param {Event} e the mousemove event
         * @param {String|DragDrop[]} id In POINT mode, the element
         * id this was hovering over.  In INTERSECT mode, an array of dd items
         * that the mouse is no longer over.
         */
        onDragOut: function(e, id) { /* override this */ },

        /**
         * Code that executes immediately before the onDragDrop event
         * @method b4DragDrop
         * @private
         */
        b4DragDrop: function(e) { },

        /**
         * Abstract method called when this item is dropped on another DragDrop
         * obj
         * @method onDragDrop
         * @param {Event} e the mouseup event
         * @param {String|DragDrop[]} id In POINT mode, the element
         * id this was dropped on.  In INTERSECT mode, an array of dd items this
         * was dropped on.
         */
        onDragDrop: function(e, id) { /* override this */ },

        /**
         * Abstract method called when this item is dropped on an area with no
         * drop target
         * @method onInvalidDrop
         * @param {Event} e the mouseup event
         */
        onInvalidDrop: function(e) { /* override this */ },

        /**
         * Code that executes immediately before the endDrag event
         * @method b4EndDrag
         * @private
         */
        b4EndDrag: function(e) { },

        /**
         * Fired when we are done dragging the object
         * @method endDrag
         * @param {Event} e the mouseup event
         */
        endDrag: function(e) { /* override this */ },

        /**
         * Code executed immediately before the onMouseDown event
         * @method b4MouseDown
         * @param {Event} e the mousedown event
         * @private
         */
        b4MouseDown: function(e) {  },

        /**
         * Event handler that fires when a drag/drop obj gets a mousedown
         * @method onMouseDown
         * @param {Event} e the mousedown event
         */
        onMouseDown: function(e) { /* override this */ },

        /**
         * Event handler that fires when a drag/drop obj gets a mouseup
         * @method onMouseUp
         * @param {Event} e the mouseup event
         */
        onMouseUp: function(e) { /* override this */ },

        /**
         * Override the onAvailable method to do what is needed after the initial
         * position was determined.
         * @method onAvailable
         */
        onAvailable: function () {
        },

        /**
         * Provides default constraint padding to "constrainTo" elements (defaults to {left: 0, right:0, top:0, bottom:0}).
         * @type Object
         */
        defaultPadding : {left:0, right:0, top:0, bottom:0},

        /**
         * Initializes the drag drop object's constraints to restrict movement to a certain element.
     *
     * Usage:
     <pre><code>
     var dd = new Ext.dd.DDProxy("dragDiv1", "proxytest",
                    { dragElId: "existingProxyDiv" });
     dd.startDrag = function(){
         this.constrainTo("parent-id");
     };
     </code></pre>
     * Or you can initalize it using the {@link Ext.Element} object:
     <pre><code>
     Ext.get("dragDiv1").initDDProxy("proxytest", {dragElId: "existingProxyDiv"}, {
         startDrag : function(){
             this.constrainTo("parent-id");
         }
     });
     </code></pre>
         * @param {Mixed} constrainTo The element to constrain to.
         * @param {Object/Number} pad (optional) Pad provides a way to specify "padding" of the constraints,
         * and can be either a number for symmetrical padding (4 would be equal to {left:4, right:4, top:4, bottom:4}) or
         * an object containing the sides to pad. For example: {right:10, bottom:10}
         * @param {Boolean} inContent (optional) Constrain the draggable in the content box of the element (inside padding and borders)
         */
        constrainTo : function(constrainTo, pad, inContent){
            if(Ext.isNumber(pad)){
                pad = {left: pad, right:pad, top:pad, bottom:pad};
            }
            pad = pad || this.defaultPadding;
            var b = Ext.get(this.getEl()).getBox(),
                ce = Ext.get(constrainTo),
                s = ce.getScroll(),
                c,
                cd = ce.dom;
            if(cd == document.body){
                c = { x: s.left, y: s.top, width: Ext.lib.Dom.getViewWidth(), height: Ext.lib.Dom.getViewHeight()};
            }else{
                var xy = ce.getXY();
                c = {x : xy[0], y: xy[1], width: cd.clientWidth, height: cd.clientHeight};
            }

            var topSpace = b.y - c.y,
                leftSpace = b.x - c.x;

            this.resetConstraints();
            this.setXConstraint(leftSpace - (pad.left||0), // left
                    c.width - leftSpace - b.width - (pad.right||0), //right
    				this.xTickSize
            );
            this.setYConstraint(topSpace - (pad.top||0), //top
                    c.height - topSpace - b.height - (pad.bottom||0), //bottom
    				this.yTickSize
            );
        },

        /**
         * Returns a reference to the linked element
         * @method getEl
         * @return {HTMLElement} the html element
         */
        getEl: function() {
            if (!this._domRef) {
                this._domRef = Ext.getDom(this.id);
            }

            return this._domRef;
        },

        /**
         * Returns a reference to the actual element to drag.  By default this is
         * the same as the html element, but it can be assigned to another
         * element. An example of this can be found in Ext.dd.DDProxy
         * @method getDragEl
         * @return {HTMLElement} the html element
         */
        getDragEl: function() {
            return Ext.getDom(this.dragElId);
        },

        /**
         * Sets up the DragDrop object.  Must be called in the constructor of any
         * Ext.dd.DragDrop subclass
         * @method init
         * @param id the id of the linked element
         * @param {String} sGroup the group of related items
         * @param {object} config configuration attributes
         */
        init: function(id, sGroup, config) {
            this.initTarget(id, sGroup, config);
            Event.on(this.id, "mousedown", this.handleMouseDown, this);
            // Event.on(this.id, "selectstart", Event.preventDefault);
        },

        /**
         * Initializes Targeting functionality only... the object does not
         * get a mousedown handler.
         * @method initTarget
         * @param id the id of the linked element
         * @param {String} sGroup the group of related items
         * @param {object} config configuration attributes
         */
        initTarget: function(id, sGroup, config) {

            // configuration attributes
            this.config = config || {};

            // create a local reference to the drag and drop manager
            this.DDM = Ext.dd.DDM;
            // initialize the groups array
            this.groups = {};

            // assume that we have an element reference instead of an id if the
            // parameter is not a string
            if (typeof id !== "string") {
                id = Ext.id(id);
            }

            // set the id
            this.id = id;

            // add to an interaction group
            this.addToGroup((sGroup) ? sGroup : "default");

            // We don't want to register this as the handle with the manager
            // so we just set the id rather than calling the setter.
            this.handleElId = id;

            // the linked element is the element that gets dragged by default
            this.setDragElId(id);

            // by default, clicked anchors will not start drag operations.
            this.invalidHandleTypes = { A: "A" };
            this.invalidHandleIds = {};
            this.invalidHandleClasses = [];

            this.applyConfig();

            this.handleOnAvailable();
        },

        /**
         * Applies the configuration parameters that were passed into the constructor.
         * This is supposed to happen at each level through the inheritance chain.  So
         * a DDProxy implentation will execute apply config on DDProxy, DD, and
         * DragDrop in order to get all of the parameters that are available in
         * each object.
         * @method applyConfig
         */
        applyConfig: function() {

            // configurable properties:
            //    padding, isTarget, maintainOffset, primaryButtonOnly
            this.padding           = this.config.padding || [0, 0, 0, 0];
            this.isTarget          = (this.config.isTarget !== false);
            this.maintainOffset    = (this.config.maintainOffset);
            this.primaryButtonOnly = (this.config.primaryButtonOnly !== false);

        },

        /**
         * Executed when the linked element is available
         * @method handleOnAvailable
         * @private
         */
        handleOnAvailable: function() {
            this.available = true;
            this.resetConstraints();
            this.onAvailable();
        },

         /**
         * Configures the padding for the target zone in px.  Effectively expands
         * (or reduces) the virtual object size for targeting calculations.
         * Supports css-style shorthand; if only one parameter is passed, all sides
         * will have that padding, and if only two are passed, the top and bottom
         * will have the first param, the left and right the second.
         * @method setPadding
         * @param {int} iTop    Top pad
         * @param {int} iRight  Right pad
         * @param {int} iBot    Bot pad
         * @param {int} iLeft   Left pad
         */
        setPadding: function(iTop, iRight, iBot, iLeft) {
            // this.padding = [iLeft, iRight, iTop, iBot];
            if (!iRight && 0 !== iRight) {
                this.padding = [iTop, iTop, iTop, iTop];
            } else if (!iBot && 0 !== iBot) {
                this.padding = [iTop, iRight, iTop, iRight];
            } else {
                this.padding = [iTop, iRight, iBot, iLeft];
            }
        },

        /**
         * Stores the initial placement of the linked element.
         * @method setInitPosition
         * @param {int} diffX   the X offset, default 0
         * @param {int} diffY   the Y offset, default 0
         */
        setInitPosition: function(diffX, diffY) {
            var el = this.getEl();

            if (!this.DDM.verifyEl(el)) {
                return;
            }

            var dx = diffX || 0;
            var dy = diffY || 0;

            var p = Dom.getXY( el );

            this.initPageX = p[0] - dx;
            this.initPageY = p[1] - dy;

            this.lastPageX = p[0];
            this.lastPageY = p[1];

            this.setStartPosition(p);
        },

        /**
         * Sets the start position of the element.  This is set when the obj
         * is initialized, the reset when a drag is started.
         * @method setStartPosition
         * @param pos current position (from previous lookup)
         * @private
         */
        setStartPosition: function(pos) {
            var p = pos || Dom.getXY( this.getEl() );
            this.deltaSetXY = null;

            this.startPageX = p[0];
            this.startPageY = p[1];
        },

        /**
         * Add this instance to a group of related drag/drop objects.  All
         * instances belong to at least one group, and can belong to as many
         * groups as needed.
         * @method addToGroup
         * @param sGroup {string} the name of the group
         */
        addToGroup: function(sGroup) {
            this.groups[sGroup] = true;
            this.DDM.regDragDrop(this, sGroup);
        },

        /**
         * Remove's this instance from the supplied interaction group
         * @method removeFromGroup
         * @param {string}  sGroup  The group to drop
         */
        removeFromGroup: function(sGroup) {
            if (this.groups[sGroup]) {
                delete this.groups[sGroup];
            }

            this.DDM.removeDDFromGroup(this, sGroup);
        },

        /**
         * Allows you to specify that an element other than the linked element
         * will be moved with the cursor during a drag
         * @method setDragElId
         * @param id {string} the id of the element that will be used to initiate the drag
         */
        setDragElId: function(id) {
            this.dragElId = id;
        },

        /**
         * Allows you to specify a child of the linked element that should be
         * used to initiate the drag operation.  An example of this would be if
         * you have a content div with text and links.  Clicking anywhere in the
         * content area would normally start the drag operation.  Use this method
         * to specify that an element inside of the content div is the element
         * that starts the drag operation.
         * @method setHandleElId
         * @param id {string} the id of the element that will be used to
         * initiate the drag.
         */
        setHandleElId: function(id) {
            if (typeof id !== "string") {
                id = Ext.id(id);
            }
            this.handleElId = id;
            this.DDM.regHandle(this.id, id);
        },

        /**
         * Allows you to set an element outside of the linked element as a drag
         * handle
         * @method setOuterHandleElId
         * @param id the id of the element that will be used to initiate the drag
         */
        setOuterHandleElId: function(id) {
            if (typeof id !== "string") {
                id = Ext.id(id);
            }
            Event.on(id, "mousedown",
                    this.handleMouseDown, this);
            this.setHandleElId(id);

            this.hasOuterHandles = true;
        },

        /**
         * Remove all drag and drop hooks for this element
         * @method unreg
         */
        unreg: function() {
            Event.un(this.id, "mousedown",
                    this.handleMouseDown);
            this._domRef = null;
            this.DDM._remove(this);
        },

        destroy : function(){
            this.unreg();
        },

        /**
         * Returns true if this instance is locked, or the drag drop mgr is locked
         * (meaning that all drag/drop is disabled on the page.)
         * @method isLocked
         * @return {boolean} true if this obj or all drag/drop is locked, else
         * false
         */
        isLocked: function() {
            return (this.DDM.isLocked() || this.locked);
        },

        /**
         * Fired when this object is clicked
         * @method handleMouseDown
         * @param {Event} e
         * @param {Ext.dd.DragDrop} oDD the clicked dd object (this dd obj)
         * @private
         */
        handleMouseDown: function(e, oDD){
            if (this.primaryButtonOnly && e.button != 0) {
                return;
            }

            if (this.isLocked()) {
                return;
            }

            this.DDM.refreshCache(this.groups);

            var pt = new Ext.lib.Point(Ext.lib.Event.getPageX(e), Ext.lib.Event.getPageY(e));
            if (!this.hasOuterHandles && !this.DDM.isOverTarget(pt, this) )  {
            } else {
                if (this.clickValidator(e)) {

                    // set the initial element position
                    this.setStartPosition();

                    this.b4MouseDown(e);
                    this.onMouseDown(e);

                    this.DDM.handleMouseDown(e, this);

                    if (this.preventDefault || this.stopPropagation) {
                        if (this.preventDefault) {
                            e.preventDefault();
                        }
                        if (this.stopPropagation) {
                            e.stopPropagation();
                        }
                    } else {
                        this.DDM.stopEvent(e);
                    }
                } else {

                }
            }
        },

        clickValidator: function(e) {
            var target = e.getTarget();
            return ( this.isValidHandleChild(target) &&
                        (this.id == this.handleElId ||
                            this.DDM.handleWasClicked(target, this.id)) );
        },

        /**
         * Allows you to specify a tag name that should not start a drag operation
         * when clicked.  This is designed to facilitate embedding links within a
         * drag handle that do something other than start the drag.
         * @method addInvalidHandleType
         * @param {string} tagName the type of element to exclude
         */
        addInvalidHandleType: function(tagName) {
            var type = tagName.toUpperCase();
            this.invalidHandleTypes[type] = type;
        },

        /**
         * Lets you to specify an element id for a child of a drag handle
         * that should not initiate a drag
         * @method addInvalidHandleId
         * @param {string} id the element id of the element you wish to ignore
         */
        addInvalidHandleId: function(id) {
            if (typeof id !== "string") {
                id = Ext.id(id);
            }
            this.invalidHandleIds[id] = id;
        },

        /**
         * Lets you specify a css class of elements that will not initiate a drag
         * @method addInvalidHandleClass
         * @param {string} cssClass the class of the elements you wish to ignore
         */
        addInvalidHandleClass: function(cssClass) {
            this.invalidHandleClasses.push(cssClass);
        },

        /**
         * Unsets an excluded tag name set by addInvalidHandleType
         * @method removeInvalidHandleType
         * @param {string} tagName the type of element to unexclude
         */
        removeInvalidHandleType: function(tagName) {
            var type = tagName.toUpperCase();
            // this.invalidHandleTypes[type] = null;
            delete this.invalidHandleTypes[type];
        },

        /**
         * Unsets an invalid handle id
         * @method removeInvalidHandleId
         * @param {string} id the id of the element to re-enable
         */
        removeInvalidHandleId: function(id) {
            if (typeof id !== "string") {
                id = Ext.id(id);
            }
            delete this.invalidHandleIds[id];
        },

        /**
         * Unsets an invalid css class
         * @method removeInvalidHandleClass
         * @param {string} cssClass the class of the element(s) you wish to
         * re-enable
         */
        removeInvalidHandleClass: function(cssClass) {
            for (var i=0, len=this.invalidHandleClasses.length; i<len; ++i) {
                if (this.invalidHandleClasses[i] == cssClass) {
                    delete this.invalidHandleClasses[i];
                }
            }
        },

        /**
         * Checks the tag exclusion list to see if this click should be ignored
         * @method isValidHandleChild
         * @param {HTMLElement} node the HTMLElement to evaluate
         * @return {boolean} true if this is a valid tag type, false if not
         */
        isValidHandleChild: function(node) {

            var valid = true;
            // var n = (node.nodeName == "#text") ? node.parentNode : node;
            var nodeName;
            try {
                nodeName = node.nodeName.toUpperCase();
            } catch(e) {
                nodeName = node.nodeName;
            }
            valid = valid && !this.invalidHandleTypes[nodeName];
            valid = valid && !this.invalidHandleIds[node.id];

            for (var i=0, len=this.invalidHandleClasses.length; valid && i<len; ++i) {
                valid = !Ext.fly(node).hasClass(this.invalidHandleClasses[i]);
            }

            return valid;

        },

        /**
         * Create the array of horizontal tick marks if an interval was specified
         * in setXConstraint().
         * @method setXTicks
         * @private
         */
        setXTicks: function(iStartX, iTickSize) {
            this.xTicks = [];
            this.xTickSize = iTickSize;

            var tickMap = {};

            for (var i = this.initPageX; i >= this.minX; i = i - iTickSize) {
                if (!tickMap[i]) {
                    this.xTicks[this.xTicks.length] = i;
                    tickMap[i] = true;
                }
            }

            for (i = this.initPageX; i <= this.maxX; i = i + iTickSize) {
                if (!tickMap[i]) {
                    this.xTicks[this.xTicks.length] = i;
                    tickMap[i] = true;
                }
            }

            this.xTicks.sort(this.DDM.numericSort) ;
        },

        /**
         * Create the array of vertical tick marks if an interval was specified in
         * setYConstraint().
         * @method setYTicks
         * @private
         */
        setYTicks: function(iStartY, iTickSize) {
            this.yTicks = [];
            this.yTickSize = iTickSize;

            var tickMap = {};

            for (var i = this.initPageY; i >= this.minY; i = i - iTickSize) {
                if (!tickMap[i]) {
                    this.yTicks[this.yTicks.length] = i;
                    tickMap[i] = true;
                }
            }

            for (i = this.initPageY; i <= this.maxY; i = i + iTickSize) {
                if (!tickMap[i]) {
                    this.yTicks[this.yTicks.length] = i;
                    tickMap[i] = true;
                }
            }

            this.yTicks.sort(this.DDM.numericSort) ;
        },

        /**
         * By default, the element can be dragged any place on the screen.  Use
         * this method to limit the horizontal travel of the element.  Pass in
         * 0,0 for the parameters if you want to lock the drag to the y axis.
         * @method setXConstraint
         * @param {int} iLeft the number of pixels the element can move to the left
         * @param {int} iRight the number of pixels the element can move to the
         * right
         * @param {int} iTickSize optional parameter for specifying that the
         * element
         * should move iTickSize pixels at a time.
         */
        setXConstraint: function(iLeft, iRight, iTickSize) {
            this.leftConstraint = iLeft;
            this.rightConstraint = iRight;

            this.minX = this.initPageX - iLeft;
            this.maxX = this.initPageX + iRight;
            if (iTickSize) { this.setXTicks(this.initPageX, iTickSize); }

            this.constrainX = true;
        },

        /**
         * Clears any constraints applied to this instance.  Also clears ticks
         * since they can't exist independent of a constraint at this time.
         * @method clearConstraints
         */
        clearConstraints: function() {
            this.constrainX = false;
            this.constrainY = false;
            this.clearTicks();
        },

        /**
         * Clears any tick interval defined for this instance
         * @method clearTicks
         */
        clearTicks: function() {
            this.xTicks = null;
            this.yTicks = null;
            this.xTickSize = 0;
            this.yTickSize = 0;
        },

        /**
         * By default, the element can be dragged any place on the screen.  Set
         * this to limit the vertical travel of the element.  Pass in 0,0 for the
         * parameters if you want to lock the drag to the x axis.
         * @method setYConstraint
         * @param {int} iUp the number of pixels the element can move up
         * @param {int} iDown the number of pixels the element can move down
         * @param {int} iTickSize optional parameter for specifying that the
         * element should move iTickSize pixels at a time.
         */
        setYConstraint: function(iUp, iDown, iTickSize) {
            this.topConstraint = iUp;
            this.bottomConstraint = iDown;

            this.minY = this.initPageY - iUp;
            this.maxY = this.initPageY + iDown;
            if (iTickSize) { this.setYTicks(this.initPageY, iTickSize); }

            this.constrainY = true;

        },

        /**
         * resetConstraints must be called if you manually reposition a dd element.
         * @method resetConstraints
         * @param {boolean} maintainOffset
         */
        resetConstraints: function() {
            // Maintain offsets if necessary
            if (this.initPageX || this.initPageX === 0) {
                // figure out how much this thing has moved
                var dx = (this.maintainOffset) ? this.lastPageX - this.initPageX : 0;
                var dy = (this.maintainOffset) ? this.lastPageY - this.initPageY : 0;

                this.setInitPosition(dx, dy);

            // This is the first time we have detected the element's position
            } else {
                this.setInitPosition();
            }

            if (this.constrainX) {
                this.setXConstraint( this.leftConstraint,
                                     this.rightConstraint,
                                     this.xTickSize        );
            }

            if (this.constrainY) {
                this.setYConstraint( this.topConstraint,
                                     this.bottomConstraint,
                                     this.yTickSize         );
            }
        },

        /**
         * Normally the drag element is moved pixel by pixel, but we can specify
         * that it move a number of pixels at a time.  This method resolves the
         * location when we have it set up like this.
         * @method getTick
         * @param {int} val where we want to place the object
         * @param {int[]} tickArray sorted array of valid points
         * @return {int} the closest tick
         * @private
         */
        getTick: function(val, tickArray) {
            if (!tickArray) {
                // If tick interval is not defined, it is effectively 1 pixel,
                // so we return the value passed to us.
                return val;
            } else if (tickArray[0] >= val) {
                // The value is lower than the first tick, so we return the first
                // tick.
                return tickArray[0];
            } else {
                for (var i=0, len=tickArray.length; i<len; ++i) {
                    var next = i + 1;
                    if (tickArray[next] && tickArray[next] >= val) {
                        var diff1 = val - tickArray[i];
                        var diff2 = tickArray[next] - val;
                        return (diff2 > diff1) ? tickArray[i] : tickArray[next];
                    }
                }

                // The value is larger than the last tick, so we return the last
                // tick.
                return tickArray[tickArray.length - 1];
            }
        },

        /**
         * toString method
         * @method toString
         * @return {string} string representation of the dd obj
         */
        toString: function() {
            return ("DragDrop " + this.id);
        }

    };

    })();
    /*
     * The drag and drop utility provides a framework for building drag and drop
     * applications.  In addition to enabling drag and drop for specific elements,
     * the drag and drop elements are tracked by the manager class, and the
     * interactions between the various elements are tracked during the drag and
     * the implementing code is notified about these important moments.
     */

    // Only load the library once.  Rewriting the manager class would orphan
    // existing drag and drop instances.
    if (!Ext.dd.DragDropMgr) {

    /**
     * @class Ext.dd.DragDropMgr
     * DragDropMgr 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.dd.DragDropMgr = function() {

        var Event = Ext.EventManager;

        return {

            /**
             * 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
             */
            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
             */
            handleIds: {},

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

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

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

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

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

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

            /**
             * Called the first time an element is registered.
             * @method init
             * @private
             */
            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
             */
            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
             */
            INTERSECT: 1,

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

            /**
             * @property {Boolean} [notifyOccluded=false]
             * This config is only provided to provide old, usually unwanted drag/drop behaviour.
             *
             * From ExtJS 4.1.0 onwards, when drop targets are contained in floating, absolutely positioned elements
             * such as in {@link Ext.window.Window Windows}, which may overlap each other, `over` and `drop` events
             * are only delivered to the topmost drop target at the mouse position.
             *
             * If all targets below that in zIndex order should also receive notifications, set
             * `notifyOccluded` to `true`.
             */
            notifyOccluded: false,

            /**
             * Runs method on all drag and drop objects
             * @method _execOnAll
             * @private
             */
            _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
             */
            _onLoad: function() {

                this.init();

                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
             */
            _onResize: function(e) {
                this._execOnAll("resetConstraints", []);
            },

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

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

            /**
             * Is drag and drop locked?
             * @method isLocked
             * @return {boolean} True if drag and drop is locked, false otherwise.
             */
            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
             */
            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
             */
            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
             */
            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
             */
            clickTimeThresh: 350,

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

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

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

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

            /**
             * Each DragDrop instance must be registered with the DragDropMgr.
             * 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
             */
            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
             */
            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
             */
            _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
             */
            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
             */
            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
             */
            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
             */
            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
             */
            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
             */
            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
             */
            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
             */
            handleMouseDown: function(e, oDD) {
                if(Ext.QuickTips){
                    Ext.QuickTips.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.DDM;
                            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
             */
            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
             */
            handleMouseUp: function(e) {

                if(Ext.QuickTips){
                    Ext.QuickTips.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()
             */
            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
             */
            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
             */
            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
             */
            fireEvents: function(e, isDrop) {
                var me = this,
                    dragCurrent = me.dragCurrent,
                    mousePoint = e.getPoint(),
                    overTarget,
                    overTargetEl,
                    allTargets = [],
                    oldOvers  = [],  // cache the previous dragOver array
                    outEvts   = [],
                    overEvts  = [],
                    dropEvts  = [],
                    enterEvts = [],
                    needsSort,
                    i,
                    len,
                    sGroup;

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

                // 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 (i in me.dragOvers) {
                    overTarget = me.dragOvers[i];

                    if (! me.isTypeOfDD(overTarget)) {
                        continue;
                    }

                    if (! this.isOverTarget(mousePoint, overTarget, me.mode)) {
                        outEvts.push( overTarget );
                    }

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

                // Collect all targets which are members of the same ddGoups that the dragCurrent is a member of, and which may recieve mouseover and drop notifications.
                // This is preparatory to seeing which one(s) we are currently over
                // Begin by iterating through the ddGroups of which the dragCurrent is a member
                for (sGroup in dragCurrent.groups) {

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

                    // Loop over the registered members of each group, testing each as a potential target
                    for (i in me.ids[sGroup]) {
                        overTarget = me.ids[sGroup][i];

                        // The target is valid if it is a DD type
                        // And it's got a DOM element
                        // And it's configured to be a drop target
                        // And it's not locked
                        // And it's either not the dragCurrent, or, if it is, tha dragCurrent is configured to not ignore itself.
                        if (me.isTypeOfDD(overTarget) &&
                            (overTargetEl = overTarget.getEl()) &&
                            (overTarget.isTarget) &&
                            (!overTarget.isLocked()) &&
                            ((overTarget != dragCurrent) || (dragCurrent.ignoreSelf === false))) {

                            // Only sort by zIndex if there were some which had a floating zIndex value
                            if ((overTarget.zIndex = me.getZIndex(overTargetEl)) !== -1) {
                                needsSort = true;
                            }
                            allTargets.push(overTarget);
                        }
                    }
                }

                // If there were floating targets, sort the highest zIndex to the top
                if (needsSort) {
                    allTargets.sort(me.byZIndex);
                }

                // Loop through possible targets, notifying the one(s) we are over.
                // Usually we only deliver events to the topmost.
                for (i = 0, len = allTargets.length; i < len; i++) {
                    overTarget = allTargets[i];

                    // If we are over the overTarget, queue it up to recieve an event of whatever type we are handling
                    if (me.isOverTarget(mousePoint, overTarget, me.mode)) {
                        // look for drop interactions
                        if (isDrop) {
                            dropEvts.push( overTarget );
                        // look for drag enter and drag over interactions
                        } else {
                            // initial drag over: dragEnter fires
                            if (!oldOvers[overTarget.id]) {
                                enterEvts.push( overTarget );
                            // subsequent drag overs: dragOver fires
                            } else {
                                overEvts.push( overTarget );
                            }
                            me.dragOvers[overTarget.id] = overTarget;
                        }

                        // Unless this DragDropManager has been explicitly configured to deliver events to multiple targets, then we are done.
                        if (!me.notifyOccluded) {
                            break;
                        }
                    }
                }

                if (me.mode) {
                    if (outEvts.length) {
                        dragCurrent.b4DragOut(e, outEvts);
                        dragCurrent.onDragOut(e, outEvts);
                    }

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

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

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

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

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

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

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

                }

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

            /**
             * @private
             * Collects the z-index of the passed element, looking up the parentNode axis to find an absolutely positioned ancestor
             * which is able to yield a z-index. If found to be not absolutely positionedm returns -1.
             *
             * This is used when sorting potential drop targets into z-index order so that only the topmost receives `over` and `drop` events.
             *
             * @return {Number} The z-index of the element, or of its topmost absolutely positioned ancestor. Returns -1 if the element is not
             * absolutely positioned.
             */
            getZIndex: function(element) {
                var body = document.body,
                    z,
                    zIndex = -1;

                element = Ext.getDom(element);
                while (element !== body) {
                    if (!isNaN(z = Number(Ext.fly(element).getStyle('zIndex')))) {
                        zIndex = z;
                    }
                    element = element.parentNode;
                }
                return zIndex;
            },

            /**
            * @private
            * Utility method to pass to {@link Ext.Array#sort} when sorting potential drop targets by z-index.
            */
            byZIndex: function(d1, d2) {
                return d1.zIndex < d2.zIndex;
            },

            /**
             * 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
             */
            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.DragDropMgr.refreshCache(ddinstance.groups);
             * </code>
             * Alternatively:
             * <code>
             * Ext.dd.DragDropMgr.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
             */
            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
             */
            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.lib.Region} a Region object representing the total area
             *                             the element occupies, including any padding
             *                             the instance is configured for.
             */
            getLocation: function(oDD) {
                if (! this.isTypeOfDD(oDD)) {
                    return null;
                }

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

                try {
                    pos= Ext.lib.Dom.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 new Ext.lib.Region( t, r, b, l );
            },

            /**
             * Checks the cursor location to see if it over the target
             * @method isOverTarget
             * @param {Ext.lib.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
             */
            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 = new Ext.lib.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
             */
            _onUnload: function(e, me) {
                Event.removeListener(document, "mouseup",   this.handleMouseUp, this);
                Event.removeListener(document, "mousemove", this.handleMouseMove, this);
                Event.removeListener(window,   "resize",    this._onResize, this);
                Ext.dd.DragDropMgr.unregAll();
            },

            /**
             * Cleans up the drag and drop events and objects.
             * @method unregAll
             * @private
             */
            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
             */
            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
             */
            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
             */
            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
             * @deprecated use Ext.lib.Dom instead
             */
            getCss: function(id) {
                var el = Ext.getDom(id);
                return (el) ? el.style : null;
            },

            /**
             * Inner class for cached elements
             * @class Ext.dd.DragDropMgr.ElementWrapper
             * @for DragDropMgr
             * @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 DragDropMgr
             * @deprecated use Ext.lib.Dom.getX instead
             */
            getPosX: function(el) {
                return Ext.lib.Dom.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
             * @deprecated use Ext.lib.Dom.getY instead
             */
            getPosY: function(el) {
                return Ext.lib.Dom.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
             */
            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
             */
            getScroll: function () {
                var t, l, dde=document.documentElement, db=document.body;
                if (dde && (dde.scrollTop || dde.scrollLeft)) {
                    t = dde.scrollTop;
                    l = dde.scrollLeft;
                } else if (db) {
                    t = db.scrollTop;
                    l = db.scrollLeft;
                } else {

                }
                return { top: t, left: l };
            },

            /**
             * 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
             * @deprecated use Ext.lib.Dom.getStyle
             */
            getStyle: function(el, styleProp) {
                return Ext.fly(el).getStyle(styleProp);
            },

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

            /**
             * Gets the scrollLeft
             * @method getScrollLeft
             * @return {int} the document's scrollTop
             */
            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
             */
            moveToEl: function (moveEl, targetEl) {
                var aCoord = Ext.lib.Dom.getXY(targetEl);
                Ext.lib.Dom.setXY(moveEl, aCoord);
            },

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

            /**
             * Internal counter
             * @property _timeoutCount
             * @private
             */
            _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
             */
            _addListeners: function() {
                var DDM = Ext.dd.DDM;
                if ( Ext.lib.Event && document ) {
                    DDM._onLoad();
                } else {
                    if (DDM._timeoutCount > 2000) {
                    } else {
                        setTimeout(DDM._addListeners, 10);
                        if (document && document.body) {
                            DDM._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
             */
            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;
            }

        };

    }();

    // shorter alias, save a few bytes
    Ext.dd.DDM = Ext.dd.DragDropMgr;
    Ext.dd.DDM._addListeners();

    }

    /**
     * @class Ext.dd.DD
     * A DragDrop implementation where the linked element follows the
     * mouse cursor during a drag.
     * @extends Ext.dd.DragDrop
     * @constructor
     * @param {String} id the id of the linked element
     * @param {String} sGroup the group of related DragDrop items
     * @param {object} config an object containing configurable attributes
     *                Valid properties for DD:
     *                    scroll
     */
    Ext.dd.DD = function(id, sGroup, config) {
        if (id) {
            this.init(id, sGroup, config);
        }
    };

    Ext.extend(Ext.dd.DD, Ext.dd.DragDrop, {

        /**
         * When set to true, the utility automatically tries to scroll the browser
         * window when a drag and drop element is dragged near the viewport boundary.
         * Defaults to true.
         * @property scroll
         * @type boolean
         */
        scroll: true,

        /**
         * Sets the pointer offset to the distance between the linked element's top
         * left corner and the location the element was clicked
         * @method autoOffset
         * @param {int} iPageX the X coordinate of the click
         * @param {int} iPageY the Y coordinate of the click
         */
        autoOffset: function(iPageX, iPageY) {
            var x = iPageX - this.startPageX;
            var y = iPageY - this.startPageY;
            this.setDelta(x, y);
        },

        /**
         * Sets the pointer offset.  You can call this directly to force the
         * offset to be in a particular location (e.g., pass in 0,0 to set it
         * to the center of the object)
         * @method setDelta
         * @param {int} iDeltaX the distance from the left
         * @param {int} iDeltaY the distance from the top
         */
        setDelta: function(iDeltaX, iDeltaY) {
            this.deltaX = iDeltaX;
            this.deltaY = iDeltaY;
        },

        /**
         * Sets the drag element to the location of the mousedown or click event,
         * maintaining the cursor location relative to the location on the element
         * that was clicked.  Override this if you want to place the element in a
         * location other than where the cursor is.
         * @method setDragElPos
         * @param {int} iPageX the X coordinate of the mousedown or drag event
         * @param {int} iPageY the Y coordinate of the mousedown or drag event
         */
        setDragElPos: function(iPageX, iPageY) {
            // the first time we do this, we are going to check to make sure
            // the element has css positioning

            var el = this.getDragEl();
            this.alignElWithMouse(el, iPageX, iPageY);
        },

        /**
         * Sets the element to the location of the mousedown or click event,
         * maintaining the cursor location relative to the location on the element
         * that was clicked.  Override this if you want to place the element in a
         * location other than where the cursor is.
         * @method alignElWithMouse
         * @param {HTMLElement} el the element to move
         * @param {int} iPageX the X coordinate of the mousedown or drag event
         * @param {int} iPageY the Y coordinate of the mousedown or drag event
         */
        alignElWithMouse: function(el, iPageX, iPageY) {
            var oCoord = this.getTargetCoord(iPageX, iPageY);
            var fly = el.dom ? el : Ext.fly(el, '_dd');
            if (!this.deltaSetXY) {
                var aCoord = [oCoord.x, oCoord.y];
                fly.setXY(aCoord);
                var newLeft = fly.getLeft(true);
                var newTop  = fly.getTop(true);
                this.deltaSetXY = [ newLeft - oCoord.x, newTop - oCoord.y ];
            } else {
                fly.setLeftTop(oCoord.x + this.deltaSetXY[0], oCoord.y + this.deltaSetXY[1]);
            }

            this.cachePosition(oCoord.x, oCoord.y);
            this.autoScroll(oCoord.x, oCoord.y, el.offsetHeight, el.offsetWidth);
            return oCoord;
        },

        /**
         * Saves the most recent position so that we can reset the constraints and
         * tick marks on-demand.  We need to know this so that we can calculate the
         * number of pixels the element is offset from its original position.
         * @method cachePosition
         * @param iPageX the current x position (optional, this just makes it so we
         * don't have to look it up again)
         * @param iPageY the current y position (optional, this just makes it so we
         * don't have to look it up again)
         */
        cachePosition: function(iPageX, iPageY) {
            if (iPageX) {
                this.lastPageX = iPageX;
                this.lastPageY = iPageY;
            } else {
                var aCoord = Ext.lib.Dom.getXY(this.getEl());
                this.lastPageX = aCoord[0];
                this.lastPageY = aCoord[1];
            }
        },

        /**
         * Auto-scroll the window if the dragged object has been moved beyond the
         * visible window boundary.
         * @method autoScroll
         * @param {int} x the drag element's x position
         * @param {int} y the drag element's y position
         * @param {int} h the height of the drag element
         * @param {int} w the width of the drag element
         * @private
         */
        autoScroll: function(x, y, h, w) {

            if (this.scroll) {
                // The client height
                var clientH = Ext.lib.Dom.getViewHeight();

                // The client width
                var clientW = Ext.lib.Dom.getViewWidth();

                // The amt scrolled down
                var st = this.DDM.getScrollTop();

                // The amt scrolled right
                var sl = this.DDM.getScrollLeft();

                // Location of the bottom of the element
                var bot = h + y;

                // Location of the right of the element
                var right = w + x;

                // The distance from the cursor to the bottom of the visible area,
                // adjusted so that we don't scroll if the cursor is beyond the
                // element drag constraints
                var toBot = (clientH + st - y - this.deltaY);

                // The distance from the cursor to the right of the visible area
                var toRight = (clientW + sl - x - this.deltaX);

                // How close to the edge the cursor must be before we scroll
                // var thresh = (document.all) ? 100 : 40;
                var thresh = 40;

                // How many pixels to scroll per autoscroll op.  This helps to reduce
                // clunky scrolling. IE is more sensitive about this ... it needs this
                // value to be higher.
                var scrAmt = (document.all) ? 80 : 30;

                // Scroll down if we are near the bottom of the visible page and the
                // obj extends below the crease
                if ( bot > clientH && toBot < thresh ) {
                    window.scrollTo(sl, st + scrAmt);
                }

                // Scroll up if the window is scrolled down and the top of the object
                // goes above the top border
                if ( y < st && st > 0 && y - st < thresh ) {
                    window.scrollTo(sl, st - scrAmt);
                }

                // Scroll right if the obj is beyond the right border and the cursor is
                // near the border.
                if ( right > clientW && toRight < thresh ) {
                    window.scrollTo(sl + scrAmt, st);
                }

                // Scroll left if the window has been scrolled to the right and the obj
                // extends past the left border
                if ( x < sl && sl > 0 && x - sl < thresh ) {
                    window.scrollTo(sl - scrAmt, st);
                }
            }
        },

        /**
         * Finds the location the element should be placed if we want to move
         * it to where the mouse location less the click offset would place us.
         * @method getTargetCoord
         * @param {int} iPageX the X coordinate of the click
         * @param {int} iPageY the Y coordinate of the click
         * @return an object that contains the coordinates (Object.x and Object.y)
         * @private
         */
        getTargetCoord: function(iPageX, iPageY) {
            var x = iPageX - this.deltaX;
            var y = iPageY - this.deltaY;

            if (this.constrainX) {
                if (x < this.minX) { x = this.minX; }
                if (x > this.maxX) { x = this.maxX; }
            }

            if (this.constrainY) {
                if (y < this.minY) { y = this.minY; }
                if (y > this.maxY) { y = this.maxY; }
            }

            x = this.getTick(x, this.xTicks);
            y = this.getTick(y, this.yTicks);

            return {x:x, y:y};
        },

        /**
         * Sets up config options specific to this class. Overrides
         * Ext.dd.DragDrop, but all versions of this method through the
         * inheritance chain are called
         */
        applyConfig: function() {
            Ext.dd.DD.superclass.applyConfig.call(this);
            this.scroll = (this.config.scroll !== false);
        },

        /**
         * Event that fires prior to the onMouseDown event.  Overrides
         * Ext.dd.DragDrop.
         */
        b4MouseDown: function(e) {
            // this.resetConstraints();
            this.autoOffset(e.getPageX(),
                                e.getPageY());
        },

        /**
         * Event that fires prior to the onDrag event.  Overrides
         * Ext.dd.DragDrop.
         */
        b4Drag: function(e) {
            this.setDragElPos(e.getPageX(),
                                e.getPageY());
        },

        toString: function() {
            return ("DD " + this.id);
        }

        //////////////////////////////////////////////////////////////////////////
        // Debugging ygDragDrop events that can be overridden
        //////////////////////////////////////////////////////////////////////////
        /*
        startDrag: function(x, y) {
        },

        onDrag: function(e) {
        },

        onDragEnter: function(e, id) {
        },

        onDragOver: function(e, id) {
        },

        onDragOut: function(e, id) {
        },

        onDragDrop: function(e, id) {
        },

        endDrag: function(e) {
        }

        */

    });
    /**
     * @class Ext.dd.DDProxy
     * A DragDrop implementation that inserts an empty, bordered div into
     * the document that follows the cursor during drag operations.  At the time of
     * the click, the frame div is resized to the dimensions of the linked html
     * element, and moved to the exact location of the linked element.
     *
     * References to the "frame" element refer to the single proxy element that
     * was created to be dragged in place of all DDProxy elements on the
     * page.
     *
     * @extends Ext.dd.DD
     * @constructor
     * @param {String} id the id of the linked html element
     * @param {String} sGroup the group of related DragDrop objects
     * @param {object} config an object containing configurable attributes
     *                Valid properties for DDProxy in addition to those in DragDrop:
     *                   resizeFrame, centerFrame, dragElId
     */
    Ext.dd.DDProxy = function(id, sGroup, config) {
        if (id) {
            this.init(id, sGroup, config);
            this.initFrame();
        }
    };

    /**
     * The default drag frame div id
     * @property Ext.dd.DDProxy.dragElId
     * @type String
     * @static
     */
    Ext.dd.DDProxy.dragElId = "ygddfdiv";

    Ext.extend(Ext.dd.DDProxy, Ext.dd.DD, {

        /**
         * By default we resize the drag frame to be the same size as the element
         * we want to drag (this is to get the frame effect).  We can turn it off
         * if we want a different behavior.
         * @property resizeFrame
         * @type boolean
         */
        resizeFrame: true,

        /**
         * By default the frame is positioned exactly where the drag element is, so
         * we use the cursor offset provided by Ext.dd.DD.  Another option that works only if
         * you do not have constraints on the obj is to have the drag frame centered
         * around the cursor.  Set centerFrame to true for this effect.
         * @property centerFrame
         * @type boolean
         */
        centerFrame: false,

        /**
         * Creates the proxy element if it does not yet exist
         * @method createFrame
         */
        createFrame: function() {
            var self = this;
            var body = document.body;

            if (!body || !body.firstChild) {
                setTimeout( function() { self.createFrame(); }, 50 );
                return;
            }

            var div = this.getDragEl();

            if (!div) {
                div    = document.createElement("div");
                div.id = this.dragElId;
                var s  = div.style;

                s.position   = "absolute";
                s.visibility = "hidden";
                s.cursor     = "move";
                s.border     = "2px solid #aaa";
                s.zIndex     = 999;

                // appendChild can blow up IE if invoked prior to the window load event
                // while rendering a table.  It is possible there are other scenarios
                // that would cause this to happen as well.
                body.insertBefore(div, body.firstChild);
            }
        },

        /**
         * Initialization for the drag frame element.  Must be called in the
         * constructor of all subclasses
         * @method initFrame
         */
        initFrame: function() {
            this.createFrame();
        },

        applyConfig: function() {
            Ext.dd.DDProxy.superclass.applyConfig.call(this);

            this.resizeFrame = (this.config.resizeFrame !== false);
            this.centerFrame = (this.config.centerFrame);
            this.setDragElId(this.config.dragElId || Ext.dd.DDProxy.dragElId);
        },

        /**
         * Resizes the drag frame to the dimensions of the clicked object, positions
         * it over the object, and finally displays it
         * @method showFrame
         * @param {int} iPageX X click position
         * @param {int} iPageY Y click position
         * @private
         */
        showFrame: function(iPageX, iPageY) {
            var el = this.getEl();
            var dragEl = this.getDragEl();
            var s = dragEl.style;

            this._resizeProxy();

            if (this.centerFrame) {
                this.setDelta( Math.round(parseInt(s.width,  10)/2),
                               Math.round(parseInt(s.height, 10)/2) );
            }

            this.setDragElPos(iPageX, iPageY);

            Ext.fly(dragEl).show();
        },

        /**
         * The proxy is automatically resized to the dimensions of the linked
         * element when a drag is initiated, unless resizeFrame is set to false
         * @method _resizeProxy
         * @private
         */
        _resizeProxy: function() {
            if (this.resizeFrame) {
                var el = this.getEl();
                Ext.fly(this.getDragEl()).setSize(el.offsetWidth, el.offsetHeight);
            }
        },

        // overrides Ext.dd.DragDrop
        b4MouseDown: function(e) {
            var x = e.getPageX();
            var y = e.getPageY();
            this.autoOffset(x, y);
            this.setDragElPos(x, y);
        },

        // overrides Ext.dd.DragDrop
        b4StartDrag: function(x, y) {
            // show the drag frame
            this.showFrame(x, y);
        },

        // overrides Ext.dd.DragDrop
        b4EndDrag: function(e) {
            Ext.fly(this.getDragEl()).hide();
        },

        // overrides Ext.dd.DragDrop
        // By default we try to move the element to the last location of the frame.
        // This is so that the default behavior mirrors that of Ext.dd.DD.
        endDrag: function(e) {

            var lel = this.getEl();
            var del = this.getDragEl();

            // Show the drag frame briefly so we can get its position
            del.style.visibility = "";

            this.beforeMove();
            // Hide the linked element before the move to get around a Safari
            // rendering bug.
            lel.style.visibility = "hidden";
            Ext.dd.DDM.moveToEl(lel, del);
            del.style.visibility = "hidden";
            lel.style.visibility = "";

            this.afterDrag();
        },

        beforeMove : function(){

        },

        afterDrag : function(){

        },

        toString: function() {
            return ("DDProxy " + this.id);
        }

    });
    /**
     * @class Ext.dd.DDTarget
     * A DragDrop implementation that does not move, but can be a drop
     * target.  You would get the same result by simply omitting implementation
     * for the event callbacks, but this way we reduce the processing cost of the
     * event listener and the callbacks.
     * @extends Ext.dd.DragDrop
     * @constructor
     * @param {String} id the id of the element that is a drop target
     * @param {String} sGroup the group of related DragDrop objects
     * @param {object} config an object containing configurable attributes
     *                 Valid properties for DDTarget in addition to those in
     *                 DragDrop:
     *                    none
     */
    Ext.dd.DDTarget = function(id, sGroup, config) {
        if (id) {
            this.initTarget(id, sGroup, config);
        }
    };

    // Ext.dd.DDTarget.prototype = new Ext.dd.DragDrop();
    Ext.extend(Ext.dd.DDTarget, Ext.dd.DragDrop, {
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        getDragEl: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        isValidHandleChild: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        startDrag: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        endDrag: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        onDrag: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        onDragDrop: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        onDragEnter: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        onDragOut: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        onDragOver: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        onInvalidDrop: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        onMouseDown: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        onMouseUp: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        setXConstraint: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        setYConstraint: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        resetConstraints: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        clearConstraints: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        clearTicks: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        setInitPosition: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        setDragElId: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        setHandleElId: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        setOuterHandleElId: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        addInvalidHandleClass: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        addInvalidHandleId: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        addInvalidHandleType: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        removeInvalidHandleClass: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        removeInvalidHandleId: Ext.emptyFn,
        /**
         * @hide
         * Overridden and disabled. A DDTarget does not support being dragged.
         * @method
         */
        removeInvalidHandleType: Ext.emptyFn,

        toString: function() {
            return ("DDTarget " + this.id);
        }
    });