Getting coordinates of current location iOS, Google Maps API - ios

Question

I've been struggling to change the camera's value in the Google Maps API. So that it displays the users position as soon as you open the app, using CoreLocation and passing those values into the camera.
There's some other tutorials online, but nothing that works for me.
If you could help it would be massively appreciated.
#implementation HMSBViewController{
CLLocationManager *_locationManager;
}
- (NSString *)deviceLocation
{
NSString *theLocation = [NSString stringWithFormat:#"latitude: %f longitude: %f", _locationManager.location.coordinate.latitude, _locationManager.location.coordinate.longitude];
return theLocation;
}
- (void)viewDidLoad
{
//mapView.settings.myLocationButton = YES;
mapView.myLocationEnabled = YES;
_locationManager = [[CLLocationManager alloc] init];
_locationManager.distanceFilter = kCLDistanceFilterNone;
_locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation; // Setting the accuracy to the best possible
if([_locationManager respondsToSelector:#selector(requestAlwaysAuthorization)]) {
[_locationManager requestAlwaysAuthorization];
}
[_locationManager startUpdatingLocation];
}
- (void)loadView{
CLLocation *myLocation = mapView.myLocation;
GMSMarker *marker = [[GMSMarker alloc] init];
marker.position = CLLocationCoordinate2DMake(myLocation.coordinate.latitude, myLocation.coordinate.longitude);
marker.title = #"Current Location";
marker.map = mapView;
GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:_locationManager.location.coordinate.latitude
longitude:_locationManager.location.coordinate.longitude
zoom:6];
mapView = [GMSMapView mapWithFrame:CGRectZero camera:camera];
self.view = mapView;
NSLog(#"%f, %f", _locationManager.location.coordinate.latitude, _locationManager.location.coordinate.longitude);
}
When the app runs the coordinates are always set to zero.
Thanks

Answer 1

This happens because Google Maps API only get your current location after it's placed on the controller view. To solve this limitation you should create a notification that tells your controller when the current location is available.
On your viewWillApper add this observer:
[mapView addObserver:self forKeyPath:#"myLocation" options:0 context:nil];
Then add -(void)observeValueForKeyPath:ofObject:change:context: that is called everytime the keyPath value changes. On this method you can now get the current location and animate the map to it so it shows centered in there. At the end of the method you should deregister the observer since if it's not deregistered this method will be called every time the position changes.
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
if([keyPath isEqualToString:#"myLocation"]) {
CLLocation *location = [object myLocation];
CLLocationCoordinate2D target = CLLocationCoordinate2DMake(location.coordinate.latitude, location.coordinate.longitude);
[mapView animateToLocation:target];
#try {
[map removeObserver:self forKeyPath:#"myLocation"];
} #catch(id exception){
//do nothing, obviously it wasn't attached because an exception was thrown
}
}
}
The map can take a while to get the current location, but it's usually fast.