    /**
     * This plugin provides drag and/or drop functionality for a TreeView.
     *
     * It creates a specialized instance of {@link Ext.dd.DragZone DragZone} which knows how to drag out of a
     * {@link Ext.tree.View TreeView} and loads the data object which is passed to a cooperating
     * {@link Ext.dd.DragZone DragZone}'s methods with the following properties:
     *
     *   - copy : Boolean
     *
     *     The value of the TreeView's `copy` property, or `true` if the TreeView was configured with `allowCopy: true` *and*
     *     the control key was pressed when the drag operation was begun.
     *
     *   - view : TreeView
     *
     *     The source TreeView from which the drag originated.
     *
     *   - ddel : HtmlElement
     *
     *     The drag proxy element which moves with the mouse
     *
     *   - item : HtmlElement
     *
     *     The TreeView node upon which the mousedown event was registered.
     *
     *   - records : Array
     *
     *     An Array of {@link Ext.data.Model Models} representing the selected data being dragged from the source TreeView.
     *
     * It also creates a specialized instance of {@link Ext.dd.DropZone} which cooperates with other DropZones which are
     * members of the same ddGroup which processes such data objects.
     *
     * Adding this plugin to a view means that two new events may be fired from the client TreeView, {@link #beforedrop} and
     * {@link #drop}.
     *
     * Note that the plugin must be added to the tree view, not to the tree panel. For example using viewConfig:
     *
     *     viewConfig: {
     *         plugins: { ptype: 'treeviewdragdrop' }
     *     }
     */
    Ext.define('Ext.tree.plugin.TreeViewDragDrop', {
        extend: 'Ext.AbstractPlugin',
        alias: 'plugin.treeviewdragdrop',

        uses: [
            'Ext.tree.ViewDragZone',
            'Ext.tree.ViewDropZone'
        ],

        /**
         * @event beforedrop
         *
         * **This event is fired through the TreeView. Add listeners to the TreeView object**
         *
         * Fired when a drop gesture has been triggered by a mouseup event in a valid drop position in the TreeView.
         *
         * @param {HTMLElement} node The TreeView node **if any** over which the mouse was positioned.
         *
         * Returning `false` to this event signals that the drop gesture was invalid, and if the drag proxy will animate
         * back to the point from which the drag began.
         *
         * Returning `0` To this event signals that the data transfer operation should not take place, but that the gesture
         * was valid, and that the repair operation should not take place.
         *
         * Any other return value continues with the data transfer operation.
         *
         * @param {Object} data The data object gathered at mousedown time by the cooperating
         * {@link Ext.dd.DragZone DragZone}'s {@link Ext.dd.DragZone#getDragData getDragData} method it contains the following
         * properties:
         * @param {Boolean} data.copy The value of the TreeView's `copy` property, or `true` if the TreeView was configured with
         * `allowCopy: true` and the control key was pressed when the drag operation was begun
         * @param {Ext.tree.View} data.view The source TreeView from which the drag originated.
         * @param {HTMLElement} data.ddel The drag proxy element which moves with the mouse
         * @param {HTMLElement} data.item The TreeView node upon which the mousedown event was registered.
         * @param {Ext.data.Model[]} data.records An Array of {@link Ext.data.Model Model}s representing the selected data being
         * dragged from the source TreeView.
         *
         * @param {Ext.data.Model} overModel The Model over which the drop gesture took place.
         *
         * @param {String} dropPosition `"before"`, `"after"` or `"append"` depending on whether the mouse is above or below
         * the midline of the node, or the node is a branch node which accepts new child nodes.
         *
         * @param {Function} dropFunction A function to call to complete the data transfer operation and either move or copy
         * Model instances from the source View's Store to the destination View's Store.
         *
         * This is useful when you want to perform some kind of asynchronous processing before confirming the drop, such as
         * an {@link Ext.window.MessageBox#confirm confirm} call, or an Ajax request.
         *
         * Return `0` from this event handler, and call the `dropFunction` at any time to perform the data transfer.
         */

        /**
         * @event drop
         *
         * **This event is fired through the TreeView. Add listeners to the TreeView object** Fired when a drop operation
         * has been completed and the data has been moved or copied.
         *
         * @param {HTMLElement} node The TreeView node **if any** over which the mouse was positioned.
         *
         * @param {Object} data The data object gathered at mousedown time by the cooperating
         * {@link Ext.dd.DragZone DragZone}'s {@link Ext.dd.DragZone#getDragData getDragData} method it contains the following
         * properties:
         * @param {Boolean} data.copy The value of the TreeView's `copy` property, or `true` if the TreeView was configured with
         * `allowCopy: true` and the control key was pressed when the drag operation was begun
         * @param {Ext.tree.View} data.view The source TreeView from which the drag originated.
         * @param {HTMLElement} data.ddel The drag proxy element which moves with the mouse
         * @param {HTMLElement} data.item The TreeView node upon which the mousedown event was registered.
         * @param {Ext.data.Model[]} data.records An Array of {@link Ext.data.Model Model}s representing the selected data being
         * dragged from the source TreeView.
         *
         * @param {Ext.data.Model} overModel The Model over which the drop gesture took place.
         *
         * @param {String} dropPosition `"before"`, `"after"` or `"append"` depending on whether the mouse is above or below
         * the midline of the node, or the node is a branch node which accepts new child nodes.
         */

        dragText : '{0} selected node{1}',

        /**
         * @cfg {Boolean} allowParentInsert
         * Allow inserting a dragged node between an expanded parent node and its first child that will become a sibling of
         * the parent when dropped.
         */
        allowParentInserts: false,

        /**
         * @cfg {String} allowContainerDrop
         * True if drops on the tree container (outside of a specific tree node) are allowed.
         */
        allowContainerDrops: false,

        /**
         * @cfg {String} appendOnly
         * True if the tree should only allow append drops (use for trees which are sorted).
         */
        appendOnly: false,

        /**
         * @cfg {String} ddGroup
         * A named drag drop group to which this object belongs. If a group is specified, then both the DragZones and
         * DropZone used by this plugin will only interact with other drag drop objects in the same group.
         */
        ddGroup : "TreeDD",

        /**
         * @cfg {String} dragGroup
         * The ddGroup to which the DragZone will belong.
         *
         * This defines which other DropZones the DragZone will interact with. Drag/DropZones only interact with other
         * Drag/DropZones which are members of the same ddGroup.
         */

        /**
         * @cfg {String} dropGroup
         * The ddGroup to which the DropZone will belong.
         *
         * This defines which other DragZones the DropZone will interact with. Drag/DropZones only interact with other
         * Drag/DropZones which are members of the same ddGroup.
         */

        /**
         * @cfg {String} expandDelay
         * The delay in milliseconds to wait before expanding a target tree node while dragging a droppable node over the
         * target.
         */
        expandDelay : 1000,

        /**
         * @cfg {Boolean} enableDrop
         * Set to `false` to disallow the View from accepting drop gestures.
         */
        enableDrop: true,

        /**
         * @cfg {Boolean} enableDrag
         * Set to `false` to disallow dragging items from the View.
         */
        enableDrag: true,

        /**
         * @cfg {String} nodeHighlightColor
         * The color to use when visually highlighting the dragged or dropped node (default value is light blue).
         * The color must be a 6 digit hex value, without a preceding '#'. See also {@link #nodeHighlightOnDrop} and
         * {@link #nodeHighlightOnRepair}.
         */
        nodeHighlightColor: 'c3daf9',

        /**
         * @cfg {Boolean} nodeHighlightOnDrop
         * Whether or not to highlight any nodes after they are
         * successfully dropped on their target. Defaults to the value of `Ext.enableFx`.
         * See also {@link #nodeHighlightColor} and {@link #nodeHighlightOnRepair}.
         */
        nodeHighlightOnDrop: Ext.enableFx,

        /**
         * @cfg {Boolean} nodeHighlightOnRepair
         * Whether or not to highlight any nodes after they are
         * repaired from an unsuccessful drag/drop. Defaults to the value of `Ext.enableFx`.
         * See also {@link #nodeHighlightColor} and {@link #nodeHighlightOnDrop}.
         */
        nodeHighlightOnRepair: Ext.enableFx,

        init : function(view) {
            view.on('render', this.onViewRender, this, {single: true});
        },

        /**
         * @private
         * AbstractComponent calls destroy on all its plugins at destroy time.
         */
        destroy: function() {
            Ext.destroy(this.dragZone, this.dropZone);
        },

        onViewRender : function(view) {
            var me = this;

            if (me.enableDrag) {
                me.dragZone = Ext.create('Ext.tree.ViewDragZone', {
                    view: view,
                    ddGroup: me.dragGroup || me.ddGroup,
                    dragText: me.dragText,
                    repairHighlightColor: me.nodeHighlightColor,
                    repairHighlight: me.nodeHighlightOnRepair
                });
            }

            if (me.enableDrop) {
                me.dropZone = Ext.create('Ext.tree.ViewDropZone', {
                    view: view,
                    ddGroup: me.dropGroup || me.ddGroup,
                    allowContainerDrops: me.allowContainerDrops,
                    appendOnly: me.appendOnly,
                    allowParentInserts: me.allowParentInserts,
                    expandDelay: me.expandDelay,
                    dropHighlightColor: me.nodeHighlightColor,
                    dropHighlight: me.nodeHighlightOnDrop
                });
            }
        }
    });