class HomePage extends StatelessWidget implements ConnectivityHandler {
  final _keyScaffold = new GlobalKey<ScaffoldState>();
  HomeBloc _bloc;

  @override
  Widget build(BuildContext context) {
    _bloc = BlocProvider.of<HomeBloc>(context);
    return Scaffold(
      key: _keyScaffold,
      appBar: AppBar(title: Text('Flutter Ready to Go')),
      body: StreamBuilder(
          stream: _bloc.personStream,
          builder: (context, AsyncSnapshot<Person> snapshot) {
            if(!snapshot.hasData) return Center(child: CircularProgressIndicator());
            final person = snapshot.data;
            return _buildPersonInfo(person);
          }
      ),
    );
  }

  // omitted data

  @override
  void onConnectivityChanged(ConnectivityResult connectivity) {
    showSnackBar("Connectivity changed to ${connectivity}");
    if (!_bloc.dataLoaded && (connectivity == ConnectivityResult.wifi ||
        connectivity == ConnectivityResult.mobile)) {
      _bloc.fetchData(this);
    }
  }

  @override
  void onError(String error) {
    showSnackBar(error);
  }

  void showSnackBar(String text, [int time = 2000]){
    final snackbar = new SnackBar(
      content: new Text(text),
      duration: Duration(milliseconds: time),
    );
    _keyScaffold?.currentState.showSnackBar(snackbar);
  }
}