Function _getCloseStream

src/material/datepicker/datepicker-base.ts:860–880

Gets an observable that will emit when the overlay is supposed to be closed.

(overlayRef: OverlayRef)

  /** Gets an observable that will emit when the overlay is supposed to be closed. */
  private _getCloseStream(overlayRef: OverlayRef) {
    const ctrlShiftMetaModifiers: ModifierKey[] = ['ctrlKey', 'shiftKey', 'metaKey'];
    return merge(
      overlayRef.backdropClick(),
      overlayRef.detachments(),
      overlayRef.keydownEvents().pipe(
        filter(event => {
          // Closing on alt + up is only valid when there's an input associated with the datepicker.
          return (
            (event.keyCode === ESCAPE && !hasModifierKey(event)) ||
            (this.datepickerInput &&
              hasModifierKey(event, 'altKey') &&
              event.keyCode === UP_ARROW &&
              ctrlShiftMetaModifiers.every(
                (modifier: ModifierKey) => !hasModifierKey(event, modifier),
              ))
          );
        }),
      ),
    );
  }
}