Flutter adjust/scale google map zoom level based on circle radius

Question

I'd like to scale google map zoom level based on the radius of the circle. Technically I want the user to see circle on map at optimum zoom level. I tried to get bounds and adjust camera position, but circle does not have any such bounds parameter..

GoogleMap(
            onMapCreated: (GoogleMapController controller) {
               controller.showMarkerInfoWindow(MarkerId("0"));
            },
            circles: Set.from([
              Circle(
                circleId: CircleId("0"),
                center: LatLng(...),
                radius: 1000,
              )
            ]),
            initialCameraPosition: CameraPosition(
              target: LatLng(..),
              **zoom: 15, // I want to scale zoom based on radius of circle.**
            ),
            markers: {
              Marker(
                markerId: MarkerId("0"),
                position: LatLng(..),
                infoWindow: InfoWindow(title: ...)
              )
            },
          ),
        ),

Thanks in Advance.

score 9 · Accepted Answer · answered Nov 13 '20 at 23:40

9

After some search, found a solution here which is in java for android application.

dart/flutter code would be as follows:

double getZoomLevel(double radius) {
    double zoomLevel = 11;
    if (radius > 0) {
      double radiusElevated = radius + radius / 2;
      double scale = radiusElevated / 500;
      zoomLevel = 16 - log(scale) / log(2);
    }
    zoomLevel = num.parse(zoomLevel.toStringAsFixed(2));
    return zoomLevel;
  }

answered Nov 13 '20 at 23:40

gavrbhat

210
3
8

2

I think should `import 'dart:math' as math;` after use `math.log()`. It help us avoid error: The name 'log' is defined in the libraries 'dart:developer' and 'dart:math'. – Doan Bui Dec 01 '20 at 02:41
where you get the radius ? a more detail example will be appreciated. – Ali Yar Khan May 30 '21 at 05:40
Is there a way to do the process in opposite manner? That is convert zoom level to radius – Huzaifa Asif Jun 28 '21 at 08:03

Flutter adjust/scale google map zoom level based on circle radius

1 Answers1