Method _validateDrawers

src/material/sidenav/drawer.ts:1032–1060

Validate the state of the drawer children components.

()

  /** Validate the state of the drawer children components. */
  private _validateDrawers() {
    this._start = this._end = null;

    // Ensure that we have at most one start and one end drawer.
    this._drawers.forEach(drawer => {
      if (drawer.position == 'end') {
        if (this._end != null && (typeof ngDevMode === 'undefined' || ngDevMode)) {
          throwMatDuplicatedDrawerError('end');
        }
        this._end = drawer;
      } else {
        if (this._start != null && (typeof ngDevMode === 'undefined' || ngDevMode)) {
          throwMatDuplicatedDrawerError('start');
        }
        this._start = drawer;
      }
    });

    this._right = this._left = null;

    // Detect if we're LTR or RTL.
    if (this._dir && this._dir.value === 'rtl') {
      this._left = this._end;
      this._right = this._start;
    } else {
      this._left = this._start;
      this._right = this._end;
    }
  }

  /** Whether the container is being pushed to the side by one of the drawers. */
  private _isPushed() {