Center poly line google maps plugin flutter fit to screen google map

void _setMapFitToTour(Set<Polyline> p) {    double minLat = p.first.points.first.latitude;    double minLong = p.first.points.first.longitude;    double maxLat = p.first.points.first.latitude;    double maxLong = p.first.points.first.longitude;    p.forEach((poly) {      poly.points.forEach((point) {        if(point.latitude < minLat) minLat = point.latitude;        if(point.latitude > maxLat) maxLat = point.latitude;        if(point.longitude < minLong) minLong = point.longitude;        if(point.longitude > maxLong) maxLong = point.longitude;      });    });    mapController.moveCamera(CameraUpdate.newLatLngBounds(LatLngBounds(      southwest: LatLng(minLat, minLong),      northeast: LatLng(maxLat,maxLong)    ), 20));  }

google_maps_flutter: ^0.5.30flutter_polyline_points: ^0.2.2

Make sure you have used .then() function because setPolyline() is the async function and has the await keyword.Use these dependencies

class ShowMap extends StatefulWidget {  ShowMap({Key key}) : super(key: key);  @override  _ShowMapState createState() => _ShowMapState();}class _ShowMapState extends State<ShowMap> {  GoogleMapController _googleMapController;  Set<Polyline> _polylines = {};  List<LatLng> polylineCoordinates = [];  PolylinePoints polylinePoints = PolylinePoints();  String googleAPIKey = "YOUR_API_KEY_HERE";  @override  Widget build(BuildContext context) {    return Scaffold(      backgroundColor: ColorUtils.bluePrimary,      appBar: AppBar(        // automaticallyImplyLeading: false,        backgroundColor: ColorUtils.greenPrimary,        title: Center(          child: Column(            children: [              Text(                'Delivery Accepted! ',                style: TextStyle(fontSize: 18.0, letterSpacing: -0.3333),              ),                         ],          ),        ),      ),      body: Column(        children: [          Expanded(            flex: 5,            child: Center(              child: Container(                margin: EdgeInsets.only(top: 10),                decoration: BoxDecoration(                    // color: Colors.white,                    ),                width: MediaQuery.of(context).size.width - 10,                height: MediaQuery.of(context).size.height * 0.5,                child: GoogleMap(                    cameraTargetBounds: CameraTargetBounds.unbounded,                    initialCameraPosition: _initialPosition,                    onMapCreated: _onMapCreated,                    tiltGesturesEnabled: true,                    scrollGesturesEnabled: true,                    zoomGesturesEnabled: true,                    // trafficEnabled: true,                    polylines: _polylines),              ),            ),          ),          ),        ],      ),    );  }  static final CameraPosition _initialPosition = CameraPosition(      // bearing: 192.8334901395799,      target: LatLng(31.5204, 74.3587),      zoom: 12);  void _onMapCreated(GoogleMapController controller) async {    setState(() {      _googleMapController = controller;      setPolylines().then((_) => _setMapFitToTour(_polylines));    });  }  void _setMapFitToTour(Set<Polyline> p) {    double minLat = p.first.points.first.latitude;    double minLong = p.first.points.first.longitude;    double maxLat = p.first.points.first.latitude;    double maxLong = p.first.points.first.longitude;    p.forEach((poly) {      poly.points.forEach((point) {        if (point.latitude < minLat) minLat = point.latitude;        if (point.latitude > maxLat) maxLat = point.latitude;        if (point.longitude < minLong) minLong = point.longitude;        if (point.longitude > maxLong) maxLong = point.longitude;      });    });    _googleMapController.animateCamera(CameraUpdate.newLatLngBounds(        LatLngBounds(            southwest: LatLng(minLat, minLong),            northeast: LatLng(maxLat, maxLong)),        20));  }  setPolylines() async {    PolylineResult result = await polylinePoints.getRouteBetweenCoordinates(      googleAPIKey,      PointLatLng(31.5204, 74.3587),      PointLatLng(31.4504, 74.1350),    );    if (result.points.isNotEmpty) {      result.points.forEach((PointLatLng point) {        polylineCoordinates.add(LatLng(point.latitude, point.longitude));      });    } else {      print("--address not found ---");    }    setState(() {      Polyline polyline = Polyline(          polylineId: PolylineId("poly"),          color: Color.fromARGB(255, 40, 122, 198),          width: 5,          points: polylineCoordinates);      _polylines.add(polyline);    });  }}

Today I got the same problem and I stumbled upon your question. Looking through the answers while implementing i found a simpler approach.

The LatLangBounds class has a method in there called .fromPoint(List<LatLng> points) which takes a list of points and returns the bounds.

I used this with the MapController class and it worked perfectly showing the bounds on the map. Per my understanding of GoogleMapController it should work.

mapController.fitBounds(LatLngBounds.fromPoints(list_of_points));

Ideally this should be what the google map equivalent should be

googleMapController.moveCamera(  CameraUpdate.newLatLngBounds(    LatLngBounds.fromPoints(list_of_points)  ),zoomIndex));

The .fromPoints(List<LatLng> points) method does what everyone has virtually implemented. Hopefully this helps anyone who needs it.