mobile-app/lib/presentation/screens/plot_detail/sc_plot_parameter.dart

import 'package:farm_tpf/custom_model/EnvironmentParameter.dart';
import 'package:farm_tpf/data/repository/repository.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/const_string.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:farm_tpf/utils/formatter.dart';

import 'bloc/plot_parameter_bloc.dart';

class PlotParameterScreen extends StatefulWidget {
  final int cropId;
  PlotParameterScreen({@required this.cropId});
  @override
  _PlotParameterScreenState createState() => _PlotParameterScreenState();
}

class _PlotParameterScreenState extends State<PlotParameterScreen> {
  @override
  Widget build(BuildContext context) {
    return BlocProvider(
      create: (context) => PlotParameterBloc(repository: Repository())
        ..add(DataFetched(cropId: widget.cropId)),
      child: HoldInfinityWidget(
        cropId: widget.cropId,
      ),
    );
  }
}

class HoldInfinityWidget extends StatelessWidget {
  final int cropId;
  HoldInfinityWidget({@required this.cropId});
  final GlobalKey<ScaffoldState> _scaffoldKey = new GlobalKey<ScaffoldState>();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        key: _scaffoldKey,
        body: InfinityView(
          cropId: cropId,
        ));
  }
}

class InfinityView extends StatefulWidget {
  final int cropId;
  InfinityView({@required this.cropId});
  @override
  _InfinityViewState createState() => _InfinityViewState();
}

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

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

  @override
  Widget build(BuildContext context) {
    return Column(
      children: <Widget>[
        Expanded(child: BlocBuilder<PlotParameterBloc, PlotParameterState>(
          builder: (context, state) {
            if (state is PlotParameterFailure) {
              return Center(child: Text(state.errorString));
            }
            if (state is PlotParameterSuccess) {
              if (state.items.isEmpty) {
                return Center(child: Text(label_list_empty));
              }
              return RefreshIndicator(
                  child: ListView.builder(
                    physics: AlwaysScrollableScrollPhysics(),
                    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 {
                    _plotParameterBloc.add(OnRefresh(cropId: widget.cropId));
                  });
            }
            return Center(
              child: LoadingListPage(),
            );
          },
        ))
      ],
    );
  }

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

class ItemInfinityWidget extends StatelessWidget {
  final EnvironmentParameter item;

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

  @override
  Widget build(BuildContext context) {
    return Card(
      child: ListTile(
        title: Text(
          "${item.name ?? ''}",
          style: TextStyle(fontWeight: FontWeight.bold),
        ),
        subtitle: Text(
          item.index.formatNumtoStringDecimal(),
          style: TextStyle(color: Colors.blue, fontWeight: FontWeight.bold),
        ),
        trailing: Text(item.executeDate.format_DDMMYY_HHmm()),
      ),
    );
  }
}