Method _getOrigin

src/material/tooltip/tooltip.ts:629–658

* Returns the origin position and a fallback position based on the user's position preference. * The fallback position is the inverse of the origin (e.g. `'below' -> 'above'`).

()

   * The fallback position is the inverse of the origin (e.g. `'below' -> 'above'`).
   */
  _getOrigin(): {main: OriginConnectionPosition; fallback: OriginConnectionPosition} {
    const isLtr = !this._dir || this._dir.value == 'ltr';
    const position = this.position;
    let originPosition: OriginConnectionPosition;

    if (position == 'above' || position == 'below') {
      originPosition = {originX: 'center', originY: position == 'above' ? 'top' : 'bottom'};
    } else if (
      position == 'before' ||
      (position == 'left' && isLtr) ||
      (position == 'right' && !isLtr)
    ) {
      originPosition = {originX: 'start', originY: 'center'};
    } else if (
      position == 'after' ||
      (position == 'right' && isLtr) ||
      (position == 'left' && !isLtr)
    ) {
      originPosition = {originX: 'end', originY: 'center'};
    } else if (typeof ngDevMode === 'undefined' || ngDevMode) {
      throw getMatTooltipInvalidPositionError(position);
    }

    const {x, y} = this._invertPosition(originPosition!.originX, originPosition!.originY);

    return {
      main: originPosition!,
      fallback: {originX: x, originY: y},
    };
  }

  /** Returns the overlay position and a fallback position based on the user's preference */
  _getOverlayPosition(): {main: OverlayConnectionPosition; fallback: OverlayConnectionPosition} {