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YUI.add('widget-uievents', function (Y, NAME) {

/**

 * Support for Widget UI Events (Custom Events fired by the widget, which wrap the underlying DOM events - e.g. widget:click, widget:mousedown)

 *

 * @module widget

 * @submodule widget-uievents

 */

var BOUNDING_BOX = "boundingBox",

    Widget = Y.Widget,

    RENDER = "render",

    L = Y.Lang,

    EVENT_PREFIX_DELIMITER = ":",

    //  Map of Node instances serving as a delegation containers for a specific

    //  event type to Widget instances using that delegation container.

    _uievts = Y.Widget._uievts = Y.Widget._uievts || {};

Y.mix(Widget.prototype, {

    /**

     * Destructor logic for UI event infrastructure,

     * invoked during Widget destruction.

     *

     * @method _destroyUIEvents

     * @for Widget

     * @private

     */

    _destroyUIEvents: function() {

        var widgetGuid = Y.stamp(this, true);

        Y.each(_uievts, function (info, key) {

            if (info.instances[widgetGuid]) {

                //  Unregister this Widget instance as needing this delegated

                //  event listener.

                delete info.instances[widgetGuid];

                //  There are no more Widget instances using this delegated

                //  event listener, so detach it.

                if (Y.Object.isEmpty(info.instances)) {

                    info.handle.detach();

                    if (_uievts[key]) {

                        delete _uievts[key];

                    }

                }

            }

        });

    },

    /**

     * Map of DOM events that should be fired as Custom Events by the

     * Widget instance.

     *

     * @property UI_EVENTS

     * @for Widget

     * @type Object

     */

    UI_EVENTS: Y.Node.DOM_EVENTS,

    /**

     * Returns the node on which to bind delegate listeners.

     *

     * @method _getUIEventNode

     * @for Widget

     * @protected

     */

    _getUIEventNode: function () {

        return this.get(BOUNDING_BOX);

    },

    /**

     * Binds a delegated DOM event listener of the specified type to the

     * Widget's outtermost DOM element to facilitate the firing of a Custom

     * Event of the same type for the Widget instance.

     *

     * @method _createUIEvent

     * @for Widget

     * @param type {String} String representing the name of the event

     * @private

     */

    _createUIEvent: function (type) {

        var uiEvtNode = this._getUIEventNode(),

            key = (Y.stamp(uiEvtNode) + type),

            info = _uievts[key],

            handle;

        //  For each Node instance: Ensure that there is only one delegated

        //  event listener used to fire Widget UI events.

        if (!info) {

            handle = uiEvtNode.delegate(type, function (evt) {

                var widget = Widget.getByNode(this);

                // Widget could be null if node instance belongs to

                // another Y instance.

                if (widget) {

                    if (widget._filterUIEvent(evt)) {

                        widget.fire(evt.type, { domEvent: evt });

                    }

                }

            }, "." + Y.Widget.getClassName());

            _uievts[key] = info = { instances: {}, handle: handle };

        }

        //  Register this Widget as using this Node as a delegation container.

        info.instances[Y.stamp(this)] = 1;

    },

    /**

     * This method is used to determine if we should fire

     * the UI Event or not. The default implementation makes sure

     * that for nested delegates (nested unrelated widgets), we don't

     * fire the UI event listener more than once at each level.

     *

     * <p>For example, without the additional filter, if you have nested

     * widgets, each widget will have a delegate listener. If you

     * click on the inner widget, the inner delegate listener's

     * filter will match once, but the outer will match twice

     * (based on delegate's design) - once for the inner widget,

     * and once for the outer.</p>

     *

     * @method _filterUIEvent

     * @for Widget

     * @param {DOMEventFacade} evt

     * @return {boolean} true if it's OK to fire the custom UI event, false if not.

     * @private

     *

     */

    _filterUIEvent: function(evt) {

        // Either it's hitting this widget's delegate container (and not some other widget's),

        // or the container it's hitting is handling this widget's ui events.

        return (evt.currentTarget.compareTo(evt.container) || evt.container.compareTo(this._getUIEventNode()));

    },

    /**

     * Determines if the specified event is a UI event.

     *

     * @private

     * @method _isUIEvent

     * @for Widget

     * @param type {String} String representing the name of the event

     * @return {String} Event Returns the name of the UI Event, otherwise

     * undefined.

     */

    _getUIEvent: function (type) {

        if (L.isString(type)) {

            var sType = this.parseType(type)[1],

                iDelim,

                returnVal;

            if (sType) {

                // TODO: Get delimiter from ET, or have ET support this.

                iDelim = sType.indexOf(EVENT_PREFIX_DELIMITER);

                if (iDelim > -1) {

                    sType = sType.substring(iDelim + EVENT_PREFIX_DELIMITER.length);

                }

                if (this.UI_EVENTS[sType]) {

                    returnVal = sType;

                }

            }

            return returnVal;

        }

    },

    /**

     * Sets up infrastructure required to fire a UI event.

     *

     * @private

     * @method _initUIEvent

     * @for Widget

     * @param type {String} String representing the name of the event

     * @return {String}

     */

    _initUIEvent: function (type) {

        var sType = this._getUIEvent(type),

            queue = this._uiEvtsInitQueue || {};

        if (sType && !queue[sType]) {

            Y.log("Deferring creation of " + type + " delegate until render.", "info", "widget");

            this._uiEvtsInitQueue = queue[sType] = 1;

            this.after(RENDER, function() {

                this._createUIEvent(sType);

                delete this._uiEvtsInitQueue[sType];

            });

        }

    },

    //  Override of "on" from Base to facilitate the firing of Widget events

    //  based on DOM events of the same name/type (e.g. "click", "mouseover").

    //  Temporary solution until we have the ability to listen to when

    //  someone adds an event listener (bug 2528230)

    on: function (type) {

        this._initUIEvent(type);

        return Widget.superclass.on.apply(this, arguments);

    },

    //  Override of "publish" from Base to facilitate the firing of Widget events

    //  based on DOM events of the same name/type (e.g. "click", "mouseover").

    //  Temporary solution until we have the ability to listen to when

    //  someone publishes an event (bug 2528230)

    publish: function (type, config) {

        var sType = this._getUIEvent(type);

        if (sType && config && config.defaultFn) {

            this._initUIEvent(sType);

        }

        return Widget.superclass.publish.apply(this, arguments);

    }

}, true); // overwrite existing EventTarget methods

}, '3.18.1', {"requires": ["node-event-delegate", "widget-base"]});