Google Maps iOS SDK, Getting Current Location of user
It seems Google Maps iOS SDK
cannot access to the device position.
So you have to retrieve the position by using CLLocationManager
of iOS
.
First, add the CoreLocation.framework
to your project :
- Go in
Project Navigator
- Select your project
- Click on the tab
Build Phases
- Add the
CoreLocation.framework
in theLink Binary with Libraries
Then all you need to do is to follow the basic exemple of Apple documentation.
Create a
CLLocationManager
probably in yourViewDidLoad
:if (nil == locationManager) locationManager = [[CLLocationManager alloc] init]; locationManager.delegate = self; //Configure Accuracy depending on your needs, default is kCLLocationAccuracyBest locationManager.desiredAccuracy = kCLLocationAccuracyKilometer; // Set a movement threshold for new events. locationManager.distanceFilter = 500; // meters [locationManager startUpdatingLocation];
With the CLLocationManagerDelegate
every time the position is updated, you can update the user position on your Google Maps
:
- (void)locationManager:(CLLocationManager *)manager
didUpdateLocations:(NSArray *)locations {
// If it's a relatively recent event, turn off updates to save power.
CLLocation* location = [locations lastObject];
NSDate* eventDate = location.timestamp;
NSTimeInterval howRecent = [eventDate timeIntervalSinceNow];
if (abs(howRecent) < 15.0) {
// Update your marker on your map using location.coordinate.latitude
//and location.coordinate.longitude);
}
}
Xcode + Swift + Google Maps iOS
Step by step recipe:
1.) Add key string to Info.plist (open as source code):
<key>NSLocationWhenInUseUsageDescription</key>
<string>This app needs your location to function properly</string>
2.) Add CLLocationManagerDelegate
to your view controller class:
class MapViewController: UIViewController, CLLocationManagerDelegate {
...
}
3.) Add CLLocationManager
into your class:
var mLocationManager = CLLocationManager()
var mDidFindMyLocation = false
4.) Ask for permission and add observer:
override func viewDidLoad() {
super.viewDidLoad()
mLocationManager.delegate = self
mLocationManager.requestWhenInUseAuthorization()
yourMapView.addObserver(self, forKeyPath: "myLocation", options: NSKeyValueObservingOptions.new, context: nil)
...
}
5.) Wait for authorization and enable location in Google Maps:
func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
if (status == CLAuthorizationStatus.authorizedWhenInUse) {
yourMapView.isMyLocationEnabled = true
}
}
6.) Add observable for change of location:
override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
if (!mDidFindMyLocation) {
let myLocation: CLLocation = change![NSKeyValueChangeKey.newKey] as! CLLocation
// do whatever you want here with the location
yourMapView.camera = GMSCameraPosition.camera(withTarget: myLocation.coordinate, zoom: 10.0)
yourMapView.settings.myLocationButton = true
mDidFindMyLocation = true
print("found location!")
}
}
That's it!
Forget my previous answer. It works well if you use the native MapKit.framework.
In fact GoogleMaps for iOS do all the work for you. You don't have to use CoreLocation directly.
The only thing you have to do is to add yourMapView.myLocationEnabled = YES;
and the framework will do everything. (Except center the map on you position).
What I have done : I simply followed the steps of the following documentation. And I got a map centered on Sydney but if I zoomed out and moved to my place (if you use a real device, otherwise use simulator tools to center on Apple's location), I could see the blue point on my position.
Now if you want to update the map to follow your position, you can copy Google example MyLocationViewController.m
that is included in the framework directory. They just add a observer on the myLocation
property to update the camera properties:
@implementation MyLocationViewController {
GMSMapView *mapView_;
BOOL firstLocationUpdate_;
}
- (void)viewDidLoad {
[super viewDidLoad];
GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:-33.868
longitude:151.2086
zoom:12];
mapView_ = [GMSMapView mapWithFrame:CGRectZero camera:camera];
mapView_.settings.compassButton = YES;
mapView_.settings.myLocationButton = YES;
// Listen to the myLocation property of GMSMapView.
[mapView_ addObserver:self
forKeyPath:@"myLocation"
options:NSKeyValueObservingOptionNew
context:NULL];
self.view = mapView_;
// Ask for My Location data after the map has already been added to the UI.
dispatch_async(dispatch_get_main_queue(), ^{
mapView_.myLocationEnabled = YES;
});
}
- (void)dealloc {
[mapView_ removeObserver:self
forKeyPath:@"myLocation"
context:NULL];
}
#pragma mark - KVO updates
- (void)observeValueForKeyPath:(NSString *)keyPath
ofObject:(id)object
change:(NSDictionary *)change
context:(void *)context {
if (!firstLocationUpdate_) {
// If the first location update has not yet been recieved, then jump to that
// location.
firstLocationUpdate_ = YES;
CLLocation *location = [change objectForKey:NSKeyValueChangeNewKey];
mapView_.camera = [GMSCameraPosition cameraWithTarget:location.coordinate
zoom:14];
}
}
@end
With the doc I gave you and the samples included in the framework you should be able to do what you want.
On any iOS device, get the user's location with Core Location. Specifically, you want the CLLocation class (and CLLocationManager).