Google map with styles

google-map-with-styles.dart

import 'package:flutter/services.dart' show rootBundle;

class _MapOnSteroids extends State<MapOnSteroids> {
  
  Completer<GoogleMapController> _controllerCompleter = Completer();

  String _mapStyle;
  bool _mapStyleLoaded = false;

  @override
  void initState() {
    super.initState();
    rootBundle.loadString('assets/map/style.json').then((jsonStyle) {
      setState(() {
        _mapStyle = jsonStyle;
        _mapStyleLoaded = true;        
      });
    });
  }
  @override
  Widget build(BuildContext context) {
    return _mapStyleLoaded ?
      GoogleMap(
        mapType: MapType.normal,
        onMapCreated: (GoogleMapController controller) {
          controller.setMapStyle(_mapStyle);
          _controllerCompleter.complete(controller);
        },
      ) :
      SizedBox();
  }
}