/*
This file is part of Ext JS 4.2

Copyright (c) 2011-2013 Sencha Inc

Contact:  http://www.sencha.com/contact

GNU General Public License Usage
This file may be used under the terms of the GNU General Public License version 3.0 as
published by the Free Software Foundation and appearing in the file LICENSE included in the
packaging of this file.

Please review the following information to ensure the GNU General Public License version 3.0
requirements will be met: http://www.gnu.org/copyleft/gpl.html.

If you are unsure which license is appropriate for your use, please contact the sales department
at http://www.sencha.com/contact.

Build date: 2013-05-16 14:36:50 (f9be68accb407158ba2b1be2c226a6ce1f649314)
*/
/**
 * This plugin provides drag and/or drop functionality for a {@link Ext.grid.View GridView}.
 *
 * It creates a specialized instance of {@link Ext.dd.DragZone DragZone} which knows how to drag out of a {@link
 * Ext.grid.View GridView} and loads the data object which is passed to a cooperating {@link Ext.dd.DragZone DragZone}'s
 * methods with the following properties:
 *
 * - `copy` : {@link Boolean}
 *
 *   The value of the {@link Ext.grid.View GridView}'s `copy` property, or `true` if the GridView was configured with `allowCopy: true` _and_
 *   the control key was pressed when the drag operation was begun.
 *
 * - `view` : {@link Ext.grid.View GridView}
 *
 *   The source GridView from which the drag originated.
 *
 * - `ddel` : HtmlElement
 *
 *   The drag proxy element which moves with the mouse
 *
 * - `item` : HtmlElement
 *
 *   The GridView node upon which the mousedown event was registered.
 *
 * - `records` : {@link Array}
 *
 *   An Array of {@link Ext.data.Model Model}s representing the selected data being dragged from the source {@link Ext.grid.View GridView}.
 *
 * 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 GridView, `{@link #beforedrop
 * beforedrop}` and `{@link #drop drop}`
 *
 *     @example
 *     Ext.create('Ext.data.Store', {
 *         storeId:'simpsonsStore',
 *         fields:['name'],
 *         data: [["Lisa"], ["Bart"], ["Homer"], ["Marge"]],
 *         proxy: {
 *             type: 'memory',
 *             reader: 'array'
 *         }
 *     });
 *
 *     Ext.create('Ext.grid.Panel', {
 *         store: 'simpsonsStore',
 *         columns: [
 *             {header: 'Name',  dataIndex: 'name', flex: true}
 *         ],
 *         viewConfig: {
 *             plugins: {
 *                 ptype: 'gridviewdragdrop',
 *                 dragText: 'Drag and drop to reorganize'
 *             }
 *         },
 *         height: 200,
 *         width: 400,
 *         renderTo: Ext.getBody()
 *     });
 */
Ext.define('Ext.grid.plugin.DragDrop', {
    extend: 'Ext.AbstractPlugin',
    alias: 'plugin.gridviewdragdrop',

    uses: [
        'Ext.view.DragZone',
        'Ext.grid.ViewDropZone'
    ],

    /**
     * @event beforedrop
     * **This event is fired through the GridView. Add listeners to the {@link Ext.grid.View GridView} object**
     *
     * Fired when a drop gesture has been triggered by a mouseup event in a valid drop position in the GridView.
     * 
     * 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.
     * 
     * The dropHandlers parameter can be used to defer the processing of this event. For example to wait for the result of 
     * a message box confirmation or an asynchronous server call. See the details of this property for more information.
     *  
     *     @example
     *     view.on('beforedrop', function(node, data, overModel, dropPosition, dropHandlers) {
     *         // Defer the handling
     *         dropHandlers.wait = true;
     *         Ext.MessageBox.confirm('Drop', 'Are you sure', function(btn){
     *             if (btn === 'yes') {
     *                 dropHandlers.processDrop();
     *             } else {
     *                 dropHandlers.cancelDrop();
     *             }
     *         });
     *     });
     * 
     * Any other return value continues with the data transfer operation, unless the wait property is set.
     *
     * @param {HTMLElement} node The {@link Ext.grid.View GridView} node **if any** over which the mouse was positioned.
     *
     * 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 GridView's `copy` property, or `true` if the GridView was configured with
     * `allowCopy: true` and the control key was pressed when the drag operation was begun
     * @param {Ext.grid.View} data.view The source GridView from which the drag originated.
     * @param {HTMLElement} data.ddel The drag proxy element which moves with the mouse
     * @param {HTMLElement} data.item The GridView 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 GridView.
     *
     * @param {Ext.data.Model} overModel The Model over which the drop gesture took place.
     *
     * @param {String} dropPosition `"before"` or `"after"` depending on whether the mouse is above or below the midline
     * of the node.
     *
     * @param {Object} dropHandlers
     * This parameter allows the developer to control when the drop action takes place. It is useful if any asynchronous
     * processing needs to be completed before performing the drop. This object has the following properties:
     * 
     * @param {Boolean} dropHandlers.wait Indicates whether the drop should be deferred. Set this property to true to defer the drop.
     * @param {Function} dropHandlers.processDrop A function to be called to complete the drop operation.
     * @param {Function} dropHandlers.cancelDrop A function to be called to cancel the drop operation.
     */

    /**
     * @event drop
     * **This event is fired through the GridView. Add listeners to the GridView object** Fired when a drop operation
     * has been completed and the data has been moved or copied.
     *
     * @param {HTMLElement} node The GridView 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:
     *
     * - `copy` : {@link Boolean}
     *
     *   The value of the GridView's `copy` property, or `true` if the GridView was configured with `allowCopy: true` and
     *   the control key was pressed when the drag operation was begun
     *
     * - `view` : {@link Ext.grid.View GridView}
     *
     *   The source GridView from which the drag originated.
     *
     * - `ddel` : HtmlElement
     *
     *   The drag proxy element which moves with the mouse
     *
     * - `item` : HtmlElement
     *
     *   The {@link Ext.grid.View GridView}{@link Ext.grid.View GridView} node upon which the mousedown event was registered.
     *
     * - `records` : {@link Array}
     *
     *   An Array of {@link Ext.data.Model Model}s representing the selected data being dragged from the source GridView.
     *
     * @param {Ext.data.Model} overModel The Model over which the drop gesture took place.
     *
     * @param {String} dropPosition `"before"` or `"after"` depending on whether the mouse is above or below the midline
     * of the node.
     */
    //<locale>

    /**
     * @cfg
     * The text to show while dragging.
     *
     * Two placeholders can be used in the text:
     *
     * - `{0}` The number of selected items.
     * - `{1}` 's' when more than 1 items (only useful for English).
     */
    dragText : '{0} selected row{1}',
    //</locale>

    /**
     * @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 : "GridDD",

    /**
     * @cfg {String} dragGroup
     * The {@link #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 {@link #ddGroup}.
     */

    /**
     * @cfg {String} dropGroup
     * The {@link #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 {@link #ddGroup}.
     */

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

    /**
     * @cfg {Boolean} enableDrag
     * `false` to disallow dragging items from the View.
     */
    enableDrag: true,
    
    /**
     * `true` to register this container with the Scrollmanager for auto scrolling during drag operations.
     * A {@link Ext.dd.ScrollManager} configuration may also be passed.
     * @cfg {Object/Boolean} containerScroll
     */
    containerScroll: false,

    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);
    },

    enable: function() {
        var me = this;
        if (me.dragZone) {
            me.dragZone.unlock();
        }
        if (me.dropZone) {
            me.dropZone.unlock();
        }
        me.callParent();
    },

    disable: function() {
        var me = this;
        if (me.dragZone) {
            me.dragZone.lock();
        }
        if (me.dropZone) {
            me.dropZone.lock();
        }
        me.callParent();
    },

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

        if (me.enableDrag) {
            if (me.containerScroll) {
                scrollEl = view.getEl();
            }
            
            me.dragZone = new Ext.view.DragZone({
                view: view,
                ddGroup: me.dragGroup || me.ddGroup,
                dragText: me.dragText,
                containerScroll: me.containerScroll,
                scrollEl: scrollEl
            });
        }

        if (me.enableDrop) {
            me.dropZone = new Ext.grid.ViewDropZone({
                view: view,
                ddGroup: me.dropGroup || me.ddGroup
            });
        }
    }
});