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

import 'dart:async';

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_color.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>
    with AutomaticKeepAliveClientMixin {
  var plotParameterBloc = PlotParameterBloc(repository: Repository());
  final _scrollController = ScrollController();
  final _scrollThreshold = 250.0;
  @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.add(DataFetched(cropId: widget.cropId));
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: <Widget>[
        Expanded(
            child: BlocBuilder<PlotParameterBloc, PlotParameterState>(
          cubit: plotParameterBloc,
          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: GridView.builder(
                    gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                        crossAxisCount: 2),
                    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();
    plotParameterBloc.close();
    super.dispose();
  }

  @override
  bool get wantKeepAlive => true;
}

class ItemInfinityWidget extends StatelessWidget {
  final EnvironmentParameter item;

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

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: EdgeInsets.all(8),
      decoration: BoxDecoration(
          color: Colors.white,
          border: Border.all(color: Colors.grey[300], width: 0.35),
          borderRadius: BorderRadius.circular(8),
          boxShadow: [
            BoxShadow(
                color: Colors.grey[300], blurRadius: 4, offset: Offset(0, 3))
          ]),
      padding: EdgeInsets.all(8),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text(
            item.index.formatNumtoStringDecimal(),
            style: TextStyle(
                color: item.status ? Colors.red : AppColors.YELLOW,
                fontWeight: FontWeight.bold,
                fontSize: 28),
          ),
          Expanded(child: Container()),
          Flexible(
            child: Text(
              "${item.name ?? ''}",
              maxLines: 2,
              style: TextStyle(fontWeight: FontWeight.bold, fontSize: 20),
            ),
          ),
          Text(item.executeDate.format_DDMMYY_HHmm(),
              style: TextStyle(fontSize: 15, color: Colors.grey))
        ],
      ),
    );
  }
}