room_detail_screen.dart

AutoDisposeStreamProvider<RoomDetailViewModel> createUsersStreamProvider({ Room room }) {
  return StreamProvider.autoDispose<RoomDetailViewModel>((ref) {
    final database = ref.watch(databaseProvider);
    final agora = ref.watch(agoraProvider);
    final currentUserStream = ref.watch(userProvider);
    if (database != null && agora != null && currentUserStream != null) {
      return currentUserStream.when(
        data: (User currentUser) {
          return database.roomStream(agoraService: agora, room: room, currentUser: currentUser);
        },
        loading: () => const Stream.empty(),
        error: (error, stackTrace) => const Stream.empty()
      );
    }
    return const Stream.empty();
  });
}

// 略

RoomDetailScreen({ @required this.room })
      : usersStreamProvider = createUsersStreamProvider(room: room);