File: event/js/event-facade-dom-touch.js

            /**
            Adds touch event facade normalization properties (touches, changedTouches, targetTouches etc.) to the DOM event facade. Adds
            touch events to the DOM events whitelist.
            
            @example
                YUI().use('event-touch', function (Y) {
                    Y.one('#myDiv').on('touchstart', function(e) {
                        ...
                    });
                });
            @module event
            @submodule event-touch
             */
            var SCALE = "scale",
                ROTATION = "rotation",
                IDENTIFIER = "identifier",
                win = Y.config.win,
                GESTURE_MAP = {};
            
            /**
             * Adds touch event facade normalization properties to the DOM event facade
             *
             * @method _touch
             * @for DOMEventFacade
             * @private
             * @param ev {Event} the DOM event
             * @param currentTarget {HTMLElement} the element the listener was attached to
             * @param wrapper {CustomEvent} the custom event wrapper for this DOM event
             */
            Y.DOMEventFacade.prototype._touch = function(e, currentTarget, wrapper) {
            
                var i,l, etCached, et,touchCache;
            
                Y.log("Calling facade._touch() with e = " + e, "debug", "event-touch");
            
                if (e.touches) {
                    Y.log("Found e.touches. Replicating on facade", "info", "event-touch");
            
                    /**
                     * Array of individual touch events for touch points that are still in
                     * contact with the touch surface.
                     *
                     * @property touches
                     * @type {DOMEventFacade[]}
                     */
                    this.touches = [];
                    touchCache = {};
            
                    for (i = 0, l = e.touches.length; i < l; ++i) {
                        et = e.touches[i];
                        touchCache[Y.stamp(et)] = this.touches[i] = new Y.DOMEventFacade(et, currentTarget, wrapper);
                    }
                }
            
                if (e.targetTouches) {
                    Y.log("Found e.targetTouches. Replicating on facade", "info", "event-touch");
            
                    /**
                     * Array of individual touch events still in contact with the touch
                     * surface and whose `touchstart` event occurred inside the same taregt
                     * element as the current target element.
                     *
                     * @property targetTouches
                     * @type {DOMEventFacade[]}
                     */
                    this.targetTouches = [];
            
                    for (i = 0, l = e.targetTouches.length; i < l; ++i) {
                        et = e.targetTouches[i];
                        etCached = touchCache && touchCache[Y.stamp(et, true)];
            
                        this.targetTouches[i] = etCached || new Y.DOMEventFacade(et, currentTarget, wrapper);
            
                        if (etCached) { Y.log("Found native event in touches. Using same facade in targetTouches", "info", "event-touch"); }
                    }
                }
            
                if (e.changedTouches) {
                    Y.log("Found e.changedTouches. Replicating on facade", "info", "event-touch");
            
                    /**
                    An array of event-specific touch events.
            
                    For `touchstart`, the touch points that became active with the current
                    event.
            
                    For `touchmove`, the touch points that have changed since the last
                    event.
            
                    For `touchend`, the touch points that have been removed from the touch
                    surface.
            
                    @property changedTouches
                    @type {DOMEventFacade[]}
                    **/
                    this.changedTouches = [];
            
                    for (i = 0, l = e.changedTouches.length; i < l; ++i) {
                        et = e.changedTouches[i];
                        etCached = touchCache && touchCache[Y.stamp(et, true)];
            
                        this.changedTouches[i] = etCached || new Y.DOMEventFacade(et, currentTarget, wrapper);
            
                        if (etCached) { Y.log("Found native event in touches. Using same facade in changedTouches", "info", "event-touch"); }
                    }
                }
            
                if (SCALE in e) {
                    this[SCALE] = e[SCALE];
                }
            
                if (ROTATION in e) {
                    this[ROTATION] = e[ROTATION];
                }
            
                if (IDENTIFIER in e) {
                    this[IDENTIFIER] = e[IDENTIFIER];
                }
            };
            
            //Adding MSPointer events to whitelisted DOM Events. MSPointer event payloads
            //have the same properties as mouse events.
            if (Y.Node.DOM_EVENTS) {
                Y.mix(Y.Node.DOM_EVENTS, {
                    touchstart:1,
                    touchmove:1,
                    touchend:1,
                    touchcancel:1,
                    gesturestart:1,
                    gesturechange:1,
                    gestureend:1,
                    MSPointerDown:1,
                    MSPointerUp:1,
                    MSPointerMove:1,
                    MSPointerCancel:1,
                    pointerdown:1,
                    pointerup:1,
                    pointermove:1,
                    pointercancel:1
                });
            }
            
            //Add properties to Y.EVENT.GESTURE_MAP based on feature detection.
            if ((win && ("ontouchstart" in win)) && !(Y.UA.chrome && Y.UA.chrome < 6)) {
                GESTURE_MAP.start = ["touchstart", "mousedown"];
                GESTURE_MAP.end = ["touchend", "mouseup"];
                GESTURE_MAP.move = ["touchmove", "mousemove"];
                GESTURE_MAP.cancel = ["touchcancel", "mousecancel"];
            }
            
            else if (win && win.PointerEvent) {
                GESTURE_MAP.start = "pointerdown";
                GESTURE_MAP.end = "pointerup";
                GESTURE_MAP.move = "pointermove";
                GESTURE_MAP.cancel = "pointercancel";
            }
            
            else if (win && ("msPointerEnabled" in win.navigator)) {
                GESTURE_MAP.start = "MSPointerDown";
                GESTURE_MAP.end = "MSPointerUp";
                GESTURE_MAP.move = "MSPointerMove";
                GESTURE_MAP.cancel = "MSPointerCancel";
            }
            
            else {
                GESTURE_MAP.start = "mousedown";
                GESTURE_MAP.end = "mouseup";
                GESTURE_MAP.move = "mousemove";
                GESTURE_MAP.cancel = "mousecancel";
            }
            
            /**
             * A object literal with keys "start", "end", and "move". The value for each key is a
             * string representing the event for that environment. For touch environments, the respective
             * values are "touchstart", "touchend" and "touchmove". Mouse and MSPointer environments are also
             * supported via feature detection.
             *
             * @property _GESTURE_MAP
             * @type Object
             * @static
             */
            Y.Event._GESTURE_MAP = GESTURE_MAP;