class ListViewDataSource extends paging.PageKeyedDataSource<int, Note> {
  NoteRepository noteRepository;

  ListViewDataSource(this.noteRepository);

  @override
  Future<Tuple2<List<Note>, int>> loadInitial(int pageSize) async {
    return Tuple2(await noteRepository.getNotes(0), 1);
  }

  @override
  Future<Tuple2<List<Note>, int>> loadPageAfter(int params, int pageSize) async {
    return Tuple2(await noteRepository.getNotes(params), params + 1);
  }
}

      ListViewDataSource dataSource = ListViewDataSource(NoteRepository());

      PagingListView<Note>(
        itemBuilder: (context, data, child) => NoteWidget(data),
        pageDataSource: dataSource,
      ),