Method withRootElement

src/cdk/drag-drop/drag-ref.ts:495–515

* Sets an alternate drag root element. The root element is the element that will be moved as * the user is dragging. Passing an alternate root element is useful when trying to enable * dragging on an element that you might not have access to.

(rootElement: ElementRef<HTMLElement> | HTMLElement)

   * dragging on an element that you might not have access to.
   */
  withRootElement(rootElement: ElementRef<HTMLElement> | HTMLElement): this {
    const element = coerceElement(rootElement);

    if (element !== this._rootElement) {
      this._removeRootElementListeners();
      const renderer = this._renderer;
      this._rootElementCleanups = this._ngZone.runOutsideAngular(() => [
        renderer.listen(element, 'mousedown', this._pointerDown, activeEventListenerOptions),
        renderer.listen(element, 'touchstart', this._pointerDown, passiveEventListenerOptions),
        renderer.listen(element, 'dragstart', this._nativeDragStart, activeEventListenerOptions),
      ]);
      this._initialTransform = undefined;
      this._rootElement = element;
    }

    if (typeof SVGElement !== 'undefined' && this._rootElement instanceof SVGElement) {
      this._ownerSVGElement = this._rootElement.ownerSVGElement;
    }

    return this;
  }

  /**
   * Element to which the draggable's position will be constrained.