React Native vs Flutter - Flutter's build method

Landing.dart

@override
Widget build(BuildContext context) {
  return StoreProvider<AppState>(
    store: this.store,
    child: StoreConnector<AppState, AppState>(converter: (store) {
      return store.state;
    }, 
    builder: (context, callback) {
      if (store.state.showFilmDetails)                         // <-- 9
        return showFilmDetails(this.store.state.selectedFilm); // <-- 9
      return SingleChildScrollView(  // <-- 11
        child: Column(               // <-- 12
          children: <Widget>[
            Row(
              children: <Widget>[
                Image.asset("images/daam.png", height: 75, fit: BoxFit.cover),  // <-- 13
                Text("Dinner and a Movie",style: 
                     TextStyle( fontWeight: FontWeight.bold, fontSize: 30)),  // <-- 14
              ],
              mainAxisAlignment: MainAxisAlignment.start,
              crossAxisAlignment: CrossAxisAlignment.start,
            ), 
            Text("Tap a movie below to see its details. Then pick a date  // <-- 15
                  to see showtimes."),
            DatePicker(store.state.selectedDate, this.store),              // <-- 16
            store.state.showings == null || store.state.selectedFilm == null  // <-- 17
                ? Text("")                                                    // <-- 17
                : ShowingTimes(                                               // <-- 17
                    showings: store.state.showings,
                    selectedDate: store.state.selectedDate,
                    film: this.store.state.selectedFilm),
            Column(
                children: this.store.state.films.map<Widget>(      // <-- 18
                            (film) => new FilmBrief(film: film, store: this.store)
                          ).toList()),
          ]));
}

  Widget showFilmDetails(film) {    // <-- 19
    return SingleChildScrollView(child: Column(
      children: <Widget>[
      FilmDetails(film: this.store.state.selectedFilm,  
                         selectedDate: this.store.state.selectedDate, 
                        showings: this.store.state.showings),
      RaisedButton(
        child:Text("Done"), 
        onPressed: () => store.dispatch({'type': Actions.HIDE_FILM_DETAILS })
        ),
      ]
      ));
  }
}