mobile-app/lib/presentation/screens/plot/sc_plot.dart

import 'package:dio/dio.dart';
import 'package:farm_tpf/data/repository/repository.dart';
import 'package:farm_tpf/models/Plot.dart';
import 'package:farm_tpf/presentation/custom_widgets/bottom_loader.dart';
import 'package:farm_tpf/presentation/custom_widgets/loading_list_page.dart';
import 'package:farm_tpf/utils/bloc/infinity_scroll_bloc.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:farm_tpf/utils/const_string.dart';

class PlotListScreen extends StatefulWidget {
  @override
  _PlotListScreenState createState() => _PlotListScreenState();
}

class _PlotListScreenState extends State<PlotListScreen> {
  @override
  Widget build(BuildContext context) {
    return BlocProvider(
      create: (context) =>
          InfinityScrollBloc(repository: Repository())..add(DataFetched()),
      child: HoldInfinityWidget(),
    );
  }
}

class HoldInfinityWidget extends StatelessWidget {
  final GlobalKey<ScaffoldState> _scaffoldKey = new GlobalKey<ScaffoldState>();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        key: _scaffoldKey,
        appBar: AppBar(
          centerTitle: true,
          title: Text("Danh sách lô"),
          actions: <Widget>[
            IconButton(icon: Icon(Icons.add), onPressed: () {})
          ],
        ),
        body: InfinityView());
  }
}

class InfinityView extends StatefulWidget {
  @override
  _InfinityViewState createState() => _InfinityViewState();
}

class _InfinityViewState extends State<InfinityView> {
  final _scrollController = ScrollController();
  final _scrollThreshold = 250.0;
  InfinityScrollBloc _infinityScrollBloc;

  @override
  void initState() {
    _scrollController.addListener(() {
      final maxScroll = _scrollController.position.maxScrollExtent;
      final currentScroll = _scrollController.position.pixels;
      if (maxScroll - currentScroll < _scrollThreshold) {
        _infinityScrollBloc.add(DataFetched());
      }
    });
    _infinityScrollBloc = BlocProvider.of<InfinityScrollBloc>(context);
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return BlocBuilder<InfinityScrollBloc, InfinityScrollState>(
      builder: (context, state) {
        if (state is InfinityScrollFailure) {
          return Center(child: Text(label_error_get_data));
        }
        if (state is InfinityScrollSuccess) {
          if (state.items.isEmpty) {
            return Center(child: Text(label_list_empty));
          }
          return RefreshIndicator(
              child: ListView.builder(
                itemBuilder: (BuildContext context, int index) {
                  return index >= state.items.length
                      ? BottomLoader()
                      : ItemInfinityWidget(item: state.items[index]);
                },
                itemCount: state.hasReachedMax
                    ? state.items.length
                    : state.items.length + 1,
                controller: _scrollController,
              ),
              onRefresh: () async {
                _infinityScrollBloc.add(OnRefresh());
              });
        }
        return Center(
          child: LoadingListPage(),
        );
      },
    );
  }

  @override
  void dispose() {
    _scrollController.dispose();
    super.dispose();
  }
}

class ItemInfinityWidget extends StatelessWidget {
  final Plot item;

  const ItemInfinityWidget({Key key, @required this.item}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
        child: Card(
          child: Container(
            padding: EdgeInsets.all(8.0),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: <Widget>[
                Text("Ngày giờ: " + item.activityExecuteDate.toString()),
                SizedBox(
                  height: 8.0,
                ),
                Text("Thời gian: " + item.id.toString() + " giây"),
              ],
            ),
          ),
        ),
        onTap: () {});
  }
}