Flutter: Location package Not working on First Time App Install - dart

Question

My current app uses the Location package (link) to obtain the user's current latitude and longitude to be used to find nearby facilities.
This is the code I am using (similar to the example in the documentation)
Map<String, double> _currentLocation;
Map<String, double> _startLocation;
StreamSubscription<Map<String, double>> _locationSubscription;
String error;
bool _permission = false;
Location _location = new Location();
// Platform messages are asynchronous, so we initialize in an async method.
initPlatformState() async {
Map<String, double> location;
try {
_permission = await _location.hasPermission();
location = await _location.getLocation();
error = null;
} on PlatformException catch (e) {
if (e.code == 'PERMISSION_DENIED') {
error = 'Permission denied';
} else if (e.code == 'PERMISSION_DENIED_NEVER_ASK') {
error = 'Permission denied - please ask the user to enable it from the app settings';
}
location = null;
}
setState(() {
_startLocation = location;
print("Starting coordinates: ${_startLocation["latitude"]}, ${_startLocation["longitude"]}");
});
}
#override
void initState() {
super.initState();
initPlatformState();
_locationSubscription =
_location.onLocationChanged().listen((Map<String,double> result) {
setState(() {
_currentLocation = result;
print("Current coordinates: ${_currentLocation["latitude"]}, ${_currentLocation["longitude"]}");
});
});
}
The only problem I am facing is that whenever there is a fresh install of a new apk of the app, the app does not find the location after location permission has been granted.
After location has been granted I have set up a print statement to print out the user's location but for some reason it is not printing anything the first time only. After I restart the app then it prints out the location just fine.
First Time Opening After Install
After Restarting the App
Any experts that use the Location package that could help me with this problem?

Answer 1

According to plugin’s source code when you invoke getLocation method it asks ActivityCompat.requestPermissions to get required permission and then process. According to docs from Google:
This method functions asynchronously. It returns right away, and after the user responds to the prompt, the system calls the app's callback method with the results
, but flutter plugin has an issue about location callbacks for Android 6+ and as a workaround it is recommended to aim SDK 21.
So it seems that “native” part of this plugin doesn’t play well with Android 6+. There are two workarounds:
Set SDK to 21 version for your Android project, but I would definitely not recommend doing that.
Create some sort of “hello screen”, which will introduce the app and handle permissions there.
Meanwhile, I am really interested in what is wrong with the plugin cause its implementation seems good, so in case I’ll find how to fix it I’ll get back here.