Method open

src/material/select/select.ts:725–754

Opens the overlay panel.

()

  /** Opens the overlay panel. */
  open(): void {
    if (!this._canOpen()) {
      return;
    }

    // It's important that we read this as late as possible, because doing so earlier will
    // return a different element since it's based on queries in the form field which may
    // not have run yet. Also this needs to be assigned before we measure the overlay width.
    if (this._parentFormField) {
      this._preferredOverlayOrigin = this._parentFormField.getConnectedOverlayOrigin();
    }

    this._cleanupDetach?.();
    this._overlayWidth = this._getOverlayWidth(this._preferredOverlayOrigin);
    this._panelOpen = true;
    this._overlayDir.positionChange.pipe(take(1)).subscribe(() => {
      this._changeDetectorRef.detectChanges();
      this._positioningSettled();
    });
    this._overlayDir.attachOverlay();
    this._keyManager.withHorizontalOrientation(null);
    this._highlightCorrectOption();
    this._changeDetectorRef.markForCheck();

    // Required for the MDC form field to pick up when the overlay has been opened.
    this.stateChanges.next();

    // Simulate the animation event before we moved away from `@angular/animations`.
    Promise.resolve().then(() => this.openedChange.emit(true));
  }

  /** Closes the overlay panel and focuses the host element. */
  close(): void {