Flutter: How to animate the camera of Google Maps - google-maps

Question

I'm trying to build an app that loads a GoogleMap(), then after getting the user latitude and longitude moves to the that specific location.
I came up with this idea (code below), but it works only if I restart the app and if I don't it gives error: animateCamera was called on null.
How is it possible ? and how can i fix it ?
Thanks for answering :D
...
var mapController;
...
GoogleMap createMap() {
var initMap = GoogleMap(
onMapCreated: onMapCreated,
initialCameraPosition:
CameraPosition(target: LatLng(47.290542, 8.322641), zoom: 6.7),
);
return initMap;
}
...
void onMapCreated(controller) {
mapController = controller;
}
...
void moveCameraToUserLocation(searchedLocation2) async {
var location = await Geocode().getLatLng(searchedLocation2);
print("moving to: $location");
mapController.animateCamera(
CameraUpdate.newCameraPosition(
CameraPosition(
target: location,
zoom: 20,
),
),
);
...
build(context) {
return Scaffold(
body: createMap(),
...

Answer 1

Based on how you describe the problem, it looks like you are only calling the animate function as the map loads.
I suggest that you create a button that would handle and trigger the animate function and move the camera to the device location whenever tapped.
The following code snippet uses a ClipOval button and inside the OnTap() event you can call the method to get the device current location which will be triggered whenever the button is tapped.
ClipOval(
child: Material(
color: Colors.green[100], // button color
child: InkWell(
splashColor: Colors.green, // inkwell color
child: SizedBox(
width: 56,
height: 56,
child: Icon(Icons.my_location),
),
onTap: () {
// Add methods here that will be called whenever the button is tapped
mapController.animateCamera(CameraUpdate.newCameraPosition(CameraPosition(
target: LatLng(_currentPosition.latitude, _currentPosition.longitude),
zoom: 17.0)));
setState(() {
allMarkers.add(Marker(
markerId: MarkerId('Current Position'),
draggable: false,
position:
LatLng(_currentPosition.latitude, _currentPosition.longitude)));
});
},
),
),
)

Answer 2

Probably you are calling moveCameraToUserLocation function before map is created. From this part of the code I cannot se when you call thi function but my guess is that you call it from initstate. If you want to call this function immediately after widget is created move it to onMapCreated.
void onMapCreated(controller) {
mapController = controller;
moveCameraToUserLocation();
}