An example for Bloc users to use with infinite_scroll_pagination 5.0.0

infinite_scroll_pagination_example.dart

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:infinite_bloc_example/bloc/pagination_bloc.dart';
import 'package:infinite_scroll_pagination/infinite_scroll_pagination.dart';

import 'model/ItemModel.dart';

class ScreenMain extends StatefulWidget {
  const ScreenMain({super.key});

  @override
  State<ScreenMain> createState() => _ScreenMainState();
}

class _ScreenMainState extends State<ScreenMain> {


  final PaginationBloc _bloc = PaginationBloc();
  PagingState<int, ItemModel> pagingState = PagingState();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: BlocListener<PaginationBloc,PaginationState>(
        bloc: _bloc,
        listener: (context, state){
          if (state is PaginationStateDidReceivePagingState) {
            setState(() {
              this.pagingState = state.state;
            });
          }
        },
        child: PagedListView<int, ItemModel>(
            state: pagingState,
            fetchNextPage: (){
              if (pagingState.hasNextPage) {
                debugPrint("On Get Next Page");
                _bloc.add(PaginationEventGetPage(pagingState));
              }else{
                debugPrint("Has no more page");
              }
            },
            builderDelegate: PagedChildBuilderDelegate<ItemModel>(
                itemBuilder: (context, item, index){
                  return ListTile(
                    title: Text(item.title),
                  );
                }
            )
        ),
      ),
    );
  }
}


class PaginationBloc extends Bloc<PaginationEvent, PaginationState> {
  PaginationBloc() : super(PaginationInitial()) {
    //on<PaginationEvent>((event, emit) {
    //
    // });
    on<PaginationEventGetPage>(_getPage);
  }

  FutureOr<void> _getPage(PaginationEventGetPage event, Emitter<PaginationState> emit) async{
      var paginationState = event.state;
      emit(PaginationStateDidReceivePagingState(paginationState.copyWith(isLoading: true)));
      await Future.delayed(Duration(seconds: 2));
      var nextPage = (paginationState.keys?.last ?? 0) + 1;
      List<List<ItemModel>> loadedItems = List.from(paginationState.pages ?? []);
      var totalItems = paginationState.items?.length ?? 0;
      loadedItems.add(List.generate(10, (i)=>ItemModel(i + totalItems)));
      List<int> loadedKeys = List.from((paginationState.keys ?? []))..add(nextPage);
      var updatedState = paginationState.copyWith(
        pages: loadedItems,
        keys: loadedKeys,
        isLoading: false,
      );
      emit(PaginationStateDidReceivePagingState(updatedState));
  }
}