Uma das página da tab

eventos.dart

import 'package:bloc_pattern/bloc_pattern.dart';
import 'package:flutter/material.dart';
import 'package:minhacidade/blocs/evento_bloc.dart';
import 'package:minhacidade/pages/evento_page.dart';
import 'package:minhacidade/widgets/card_widget.dart';

class EventosPage extends StatefulWidget {
  EventosPage({Key key}) : super(key: key);

  _EventosPageState createState() => _EventosPageState();
}

class _EventosPageState extends State<EventosPage>
    with AutomaticKeepAliveClientMixin<EventosPage> {
  final _eventoBloc = BlocProvider.getBloc<EventoBloc>();

  @override
  bool get wantKeepAlive => true;

  @override
  void initState() {
    super.initState();
    _eventoBloc.getEventos();
  }

  @override
  Widget build(BuildContext context) {
    super.build(context);
    return Container(
      color: Colors.white,
      child: Padding(
        padding: const EdgeInsets.symmetric(vertical: 8, horizontal: 16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            Expanded(
              child: RefreshIndicator(
                onRefresh: (() async {
                  _eventoBloc.getUpdate();
                }),
                child: StreamBuilder(
                  stream: _eventoBloc.stream,
                  builder: (context, snapshot) {
                    switch (snapshot.connectionState) {
                      case ConnectionState.none:
                      case ConnectionState.waiting:
                        return Center(
                          child: Column(
                            mainAxisAlignment: MainAxisAlignment.center,
                            children: <Widget>[
                              Image.asset(
                                'assets/images/logo.png',
                                scale: 2,
                              ),
                              Text('Carregando...'),
                            ],
                          ),
                        );
                      default:
                        if (snapshot.hasError) {
                          return _dataEmpty(
                              "Ocorreu um erro, favor tentar novamente");
                        } else if (snapshot.hasData) {
                          if (snapshot.data.length != 0) {
                            return _createListView(snapshot.data);
                          } else {
                            return _dataEmpty("Nenhum evento encontrado");
                          }
                        } else {
                          return _dataEmpty("Nenhum evento encontrado");
                        }
                    }
                  },
                ),
              ),
            )
          ],
        ),
      ),
    );
  }

  ListView _createListView(eventos) {
    return ListView.builder(
      itemCount: eventos.length,
      itemBuilder: (context, index) {
        var evento = eventos[index];
        return GestureDetector(
          onTap: () {
            Navigator.push(context, MaterialPageRoute(
              builder: (context) => EventoPage(evento: evento,)
            ));
          },
          child: Container(
            margin: const EdgeInsets.symmetric(vertical: 8, horizontal: 8),
            child: Column(
              children: <Widget>[
                Hero(
                  tag: 'eventoImage${evento.id}',
                  child: imageCardRoundTop(context, evento.getImage(),
                    imageAssets: true, elevation: 2.0),
                ),
                cardBorderRadius(
                    context,
                    Column(
                      crossAxisAlignment: CrossAxisAlignment.end,
                      children: <Widget>[
                        Container(
                          width: MediaQuery.of(context).size.width,
                          child: Align(
                            alignment: Alignment.bottomRight,
                            child: Text(
                              evento.titulo,
                              style: Theme.of(context)
                                  .textTheme
                                  .display1
                                  .copyWith(color: Colors.black54),
                            ),
                          ),
                        ),
                        Text(
                          evento.horario,
                          style: Theme.of(context)
                              .textTheme
                              .display1
                              .copyWith(color: Colors.black54),
                        ),
                        Text(
                          "R\$ ${evento.valor.toString().replaceAll(".", ",")}",
                          style: Theme.of(context)
                              .textTheme
                              .display1
                              .copyWith(color: Colors.black54),
                        ),
                      ],
                    ),
                    topLeft: 0.0,
                    topRight: 0.0,
                    elevation: 1.0,
                    bgColor: Colors.white),
              ],
            ),
          ),
        );
      },
    );
  }

  _dataEmpty(String mensagem) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          Image.asset(
            'assets/images/logo.png',
            scale: 2,
          ),
          Text(mensagem, style: Theme.of(context).textTheme.body1.copyWith(fontSize: 18),),
        ],
      ),
    );
  }
}