/*

YUI 3.10.3 (build 2fb5187)

Copyright 2013 Yahoo! Inc. All rights reserved.

Licensed under the BSD License.

http://yuilibrary.com/license/

*/

YUI.add('dd-plugin', function (Y, NAME) {

       /**

        * Simple Drag plugin that can be attached to a Node or Widget via the plug method.

        * @module dd

        * @submodule dd-plugin

        */

       /**

        * Simple Drag plugin that can be attached to a Node or Widget via the plug method.

        * @class Drag

        * @extends DD.Drag

        * @constructor

        * @namespace Plugin

        */

        var Drag = function(config) {

                if (Y.Widget && config.host instanceof Y.Widget) {

                        config.node = config.host.get('boundingBox');

                        config.widget = config.host;

                } else {

                        config.node = config.host;

                        config.widget = false;

                }

                Drag.superclass.constructor.call(this, config);

        },

        EV_START = 'drag:start',

        EV_DRAG = 'drag:drag',

        EV_DRAG_END = 'drag:end';

        /**

        * dd-plugin

        * @property NAME

        * @type {String}

        */

        Drag.NAME = "dd-plugin";

        /**

        * The Drag instance will be placed on the Node instance under the dd namespace. It can be accessed via Node.dd;

        * @property NS

        * @type {String}

        */

        Drag.NS = "dd";

        Y.extend(Drag, Y.DD.Drag, {

                _widgetHandles: null,

                /**

                * refers to a Y.Widget if its the host, otherwise = false.

                *

                * @attribute _widget

                * @private

                */

                _widget: undefined,

                /**

                * refers to the [x,y] coordinate where the drag was stopped last

                *

                * @attribute _stoppedPosition

                * @private

                */

                _stoppedPosition: undefined,

                /**

                * Returns true if widget uses widgetPosition, otherwise returns false

                *

                * @method _usesWidgetPosition

                * @private

                */

                _usesWidgetPosition: function(widget) {

                        var r = false;

                        if (widget) {

                                r = (widget.hasImpl && widget.hasImpl(Y.WidgetPosition)) ? true : false;

                        }

                        return r;

                },

                /**

                * Attached to the `drag:start` event, it checks if this plugin needs

                * to attach or detach listeners for widgets. If `dd-proxy` is plugged

                * the default widget positioning should be ignored.

                * @method _checkEvents

                * @private

                */

                _checkEvents: function() {

                    Y.log('Checking for widget events', 'info', 'dd-plugin');

                    if (this._widget) {

                        //It's a widget

                        if (this.proxy) {

                            //It's a proxy

                            if (this._widgetHandles.length > 0) {

                                Y.log('Proxy is plugged, remove events', 'info', 'dd-plugin');

                                //Remove Listeners

                                this._removeWidgetListeners();

                            }

                        } else {

                            if (this._widgetHandles.length === 0) {

                                Y.log('Proxy is not plugged, attach events', 'info', 'dd-plugin');

                                this._attachWidgetListeners();

                            }

                        }

                    }

                },

                /**

                * Remove the attached widget listeners

                * @method _removeWidgetListeners

                * @private

                */

                _removeWidgetListeners: function() {

                    Y.log('Detaching widget events', 'info', 'dd-plugin');

                    Y.Array.each(this._widgetHandles, function(handle) {

                        handle.detach();

                    });

                    this._widgetHandles = [];

                },

                /**

                * If this is a Widget, then attach the positioning listeners

                * @method _attachWidgetListeners

                * @private

                */

                _attachWidgetListeners: function() {

                        //if this thing is a widget, and it uses widgetposition...

                        if (this._usesWidgetPosition(this._widget)) {

                            Y.log('Attaching widget events', 'info', 'dd-plugin');

                               //set the x,y on the widget's ATTRS

                               this._widgetHandles.push(this.on(EV_DRAG, this._setWidgetCoords));

                               //store the new position that the widget ends up on

                               this._widgetHandles.push(this.on(EV_DRAG_END, this._updateStopPosition));

                        }

                },

                /**

                * Sets up event listeners on drag events if interacting with a widget

                *

                * @method initializer

                * @protected

                */

                initializer: function(config) {

                        this._widgetHandles = [];

                        this._widget = config.widget;

                        this.on(EV_START, this._checkEvents); //Always run, don't check

                        this._attachWidgetListeners();

                },

                /**

                * Updates x,y or xy attributes on widget based on where the widget is dragged

                *

                * @method initializer

                * @param {EventFacade} e Event Facade

                * @private

                */

                _setWidgetCoords: function(e) {

                        //get the last position where the widget was, or get the starting point

                        var nodeXY = this._stoppedPosition || e.target.nodeXY,

                         realXY = e.target.realXY,

                         //amount moved = [(x2 - x1) , (y2 - y1)]

                         movedXY = [realXY[0] - nodeXY[0], realXY[1] - nodeXY[1]];

                         //if both have changed..

                         if (movedXY[0] !== 0 && movedXY[1] !== 0) {

                                 this._widget.set('xy', realXY);

                         }

                         //if only x is 0, set the Y

                         else if (movedXY[0] === 0) {

                                 this._widget.set('y',realXY[1]);

                         }

                         //otherwise, y is 0, so set X

                         else if (movedXY[1] === 0){

                                 this._widget.set('x', realXY[0]);

                         }

                },

                /**

                * Updates the last position where the widget was stopped.

                *

                * @method _updateStopPosition

                * @param {EventFacade} e Event Facade

                * @private

                */

                _updateStopPosition: function(e) {

                        this._stoppedPosition = e.target.realXY;

                }

        });

        Y.namespace('Plugin');

        Y.Plugin.Drag = Drag;

}, '3.10.3', {"optional": ["dd-constrain", "dd-proxy"], "requires": ["dd-drag"]});