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 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this file,

  * You can obtain one at http://mozilla.org/MPL/2.0/. */

 /* global Components, XPCOMUtils, Utils, Logger, GestureSettings,

    GestureTracker */

 /* exported PointerRelay, PointerAdapter */

 'use strict';

 const Ci = Components.interfaces;

 const Cu = Components.utils;

 this.EXPORTED_SYMBOLS = ['PointerRelay', 'PointerAdapter']; // jshint ignore:line

 Cu.import('resource://gre/modules/XPCOMUtils.jsm');

 XPCOMUtils.defineLazyModuleGetter(this, 'Utils', // jshint ignore:line

   'resource://gre/modules/accessibility/Utils.jsm');

 XPCOMUtils.defineLazyModuleGetter(this, 'Logger', // jshint ignore:line

   'resource://gre/modules/accessibility/Utils.jsm');

 XPCOMUtils.defineLazyModuleGetter(this, 'GestureSettings', // jshint ignore:line

   'resource://gre/modules/accessibility/Gestures.jsm');

 XPCOMUtils.defineLazyModuleGetter(this, 'GestureTracker', // jshint ignore:line

   'resource://gre/modules/accessibility/Gestures.jsm');

 // The virtual touch ID generated by a mouse event.

 const MOUSE_ID = 'mouse';

 // Synthesized touch ID.

 const SYNTH_ID = -1;

 let PointerRelay = { // jshint ignore:line

   /**

    * A mapping of events we should be intercepting. Entries with a value of

    * |true| are used for compiling high-level gesture events. Entries with a

    * value of |false| are cancelled and do not propogate to content.

    */

   get _eventsOfInterest() {

     delete this._eventsOfInterest;

     switch (Utils.widgetToolkit) {

       case 'gonk':

         this._eventsOfInterest = {

           'touchstart' : true,

           'touchmove' : true,

           'touchend' : true,

           'mousedown' : false,

           'mousemove' : false,

           'mouseup': false,

           'click': false };

         break;

       case 'android':

         this._eventsOfInterest = {

           'touchstart' : true,

           'touchmove' : true,

           'touchend' : true,

           'mousemove' : true,

           'mouseenter' : true,

           'mouseleave' : true,

           'mousedown' : false,

           'mouseup': false,

           'click': false };

         break;

       default:

         // Desktop.

         this._eventsOfInterest = {

           'mousemove' : true,

           'mousedown' : true,

           'mouseup': true,

           'click': false

         };

         if ('ontouchstart' in Utils.win) {

           for (let eventType of ['touchstart', 'touchmove', 'touchend']) {

             this._eventsOfInterest[eventType] = true;

           }

         }

         break;

     }

     return this._eventsOfInterest;

   },

   _eventMap: {

     'touchstart' : 'pointerdown',

     'mousedown' : 'pointerdown',

     'mouseenter' : 'pointerdown',

     'touchmove' : 'pointermove',

     'mousemove' : 'pointermove',

     'touchend' : 'pointerup',

     'mouseup': 'pointerup',

     'mouseleave': 'pointerup'

   },

   start: function PointerRelay_start(aOnPointerEvent) {

     Logger.debug('PointerRelay.start');

     this.onPointerEvent = aOnPointerEvent;

     for (let eventType in this._eventsOfInterest) {

       Utils.win.addEventListener(eventType, this, true, true);

     }

   },

   stop: function PointerRelay_stop() {

     Logger.debug('PointerRelay.stop');

     delete this.lastPointerMove;

     delete this.onPointerEvent;

     for (let eventType in this._eventsOfInterest) {

       Utils.win.removeEventListener(eventType, this, true, true);

     }

   },

   _suppressPointerMove: function PointerRelay__suppressPointerMove(aChangedTouches) {

     if (!this.lastPointerMove) {

       return false;

     }

     for (let i = 0; i < aChangedTouches.length; ++i) {

       let touch = aChangedTouches[i];

       let lastTouch;

       try {

         lastTouch = this.lastPointerMove.identifiedTouch ?

           this.lastPointerMove.identifiedTouch(touch.identifier) :

           this.lastPointerMove[i];

       } catch (x) {

         // Sometimes touch object can't be accessed after page navigation.

       }

       if (!lastTouch || lastTouch.target !== touch.target ||

         Math.hypot(touch.screenX - lastTouch.screenX, touch.screenY -

           lastTouch.screenY) / Utils.dpi >= GestureSettings.travelThreshold) {

         return false;

       }

     }

     return true;

   },

   handleEvent: function PointerRelay_handleEvent(aEvent) {

     // Don't bother with chrome mouse events.

     if (Utils.MozBuildApp === 'browser' &&

       aEvent.view.top instanceof Ci.nsIDOMChromeWindow) {

       return;

     }

     if (aEvent.mozInputSource === Ci.nsIDOMMouseEvent.MOZ_SOURCE_UNKNOWN) {

       // Ignore events that are scripted or clicks from the a11y API.

       return;

     }

     let changedTouches = aEvent.changedTouches || [{

       identifier: MOUSE_ID,

       screenX: aEvent.screenX,

       screenY: aEvent.screenY,

       target: aEvent.target

     }];

     if (changedTouches.length === 1 &&

         changedTouches[0].identifier === SYNTH_ID) {

       return;

     }

     aEvent.preventDefault();

     aEvent.stopImmediatePropagation();

     let type = aEvent.type;

     if (!this._eventsOfInterest[type]) {

       return;

     }

     let pointerType = this._eventMap[type];

     if (pointerType === 'pointermove') {

       if (this._suppressPointerMove(changedTouches)) {

         // Do not fire pointermove more than every POINTERMOVE_THROTTLE.

         return;

       }

       this.lastPointerMove = changedTouches;

     }

     this.onPointerEvent({

       type: pointerType,

       points: Array.prototype.map.call(changedTouches,

         function mapTouch(aTouch) {

           return {

             identifier: aTouch.identifier,

             x: aTouch.screenX,

             y: aTouch.screenY

           };

         }

       )

     });

   }

 };

 this.PointerAdapter = { // jshint ignore:line

   start: function PointerAdapter_start() {

     Logger.debug('PointerAdapter.start');

     GestureTracker.reset();

     PointerRelay.start(this.handleEvent);

   },

   stop: function PointerAdapter_stop() {

     Logger.debug('PointerAdapter.stop');

     PointerRelay.stop();

     GestureTracker.reset();

   },

   handleEvent: function PointerAdapter_handleEvent(aDetail) {

     let timeStamp = Date.now();

     GestureTracker.handle(aDetail, timeStamp);

   }

 };