// Since `pointermove` fires on each pixel, we need to
    // be careful not to hit the zone unless it's necessary.
    ngZone.runOutsideAngular(() => {
      this.element.addEventListener(
        'pointermove',
        event => {
          if (this._pattern.acceptsPointerMove()) {
            ngZone.run(() => this._pattern.onPointermove(event));
          }
        },
        {passive: true},
      );
    });