Method setPositionClasses

src/material/menu/menu.ts:442–452

* Adds classes to the menu panel based on its position. Can be used by * consumers to add specific styling based on the position. * @param posX Position of the menu along the x axis. * @param posY Position of the menu along the y axis. * @docs-private

(posX: MenuPositionX = this.xPosition, posY: MenuPositionY = this.yPosition)

   * @docs-private
   */
  setPositionClasses(posX: MenuPositionX = this.xPosition, posY: MenuPositionY = this.yPosition) {
    this._classList = {
      ...this._classList,
      ['mat-menu-before']: posX === 'before',
      ['mat-menu-after']: posX === 'after',
      ['mat-menu-above']: posY === 'above',
      ['mat-menu-below']: posY === 'below',
    };

    this._changeDetectorRef.markForCheck();
  }

  /** Callback that is invoked when the panel animation completes. */
  protected _onAnimationDone(state: string) {