onTouchStart_(event) {
    this.lastTouchTouchesCount_ = event.touches.length;
    if (!this.wasTwoFingerTouch())
      return;

    this.pinchStartEvent_ = event;
    this.lastEvent_ = event;
    this.notify_({type: 'pinchstart', center: GestureDetector.center_(event)});
  }
/**
   * The callback for touchstart events on the element.
   *
   * @param {!TouchEvent} event Touch event on the element.
   * @private
   */
The callback for touchstart events on the element.
@param {!TouchEvent} event Touch event on the element.
@private
The callback for touchstart events on the element . @param { !TouchEvent } event Touch event on the element . @private
onTouchStart_(event) {
    this.lastTouchTouchesCount_ = event.touches.length;
    if (!this.wasTwoFingerTouch())
      return;
    this.pinchStartEvent_ = event;
    this.lastEvent_ = event;
    this.notify_({type: 'pinchstart', center: GestureDetector.center_(event)});
  }
onTouchStart_ ( event ) { this . lastTouchTouchesCount_ = event . touches . length ; if ( ! this . wasTwoFingerTouch ( ) ) return ; this . pinchStartEvent_ = event ; this . lastEvent_ = event ; this . notify_ ( { type : 'pinchstart' , center : GestureDetector . center_ ( event ) } ) ; }
The callback for touchstart events on the element.
The callback for touchstart events on the element .