/**
* 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;