How to display a circle in GMSMapView

Question

I need to display a circle (as with MKCircle) on a GMSMapView. This is easy when using a MKMapView and MKCircle, but can\'t use MKCircle with GMSMapView. Any ideas?

Answer 1

func mapView(_ mapView: GMSMapView, didChange position: GMSCameraPosition) {
    // Make sure cicle is a GMSCircle Object  and it is a class variable
    circle.map = nil

    let point = mapView.center
    circle.position = mapView.projection.coordinate(for: point)
    circle.radius = 130.0
    circle.fillColor = .clear
    circle.strokeColor = .black
    circle.strokeWidth = 3.4
    circle.map = mapView
}

Answer 2

At the moment the SDK doesn't support circles, but there is a feature request to add circles here:

https://code.google.com/p/gmaps-api-issues/issues/detail?id=4971

In the meantime you could maybe fake a circle by drawing a polyline, with several short segments?

Answer 3

It's a bit late since the question is over a year old, but Google searches led me here, so I thought I'd update this. Posterity 4TW!

There is now a GMSCircle which can do, as far as I know, just about everything an MKCircle can.
Google's documentation on the GMSCircle.

// Build a circle for the GMSMapView
GMSCircle *geoFenceCircle = [[GMSCircle alloc] init];
geoFenceCircle.radius = 130; // Meters
geoFenceCircle.position = SOME_CLLOCATION.coordinate; // Some CLLocationCoordinate2D position
geoFenceCircle.fillColor = [UIColor colorWithWhite:0.7 alpha:0.5];
geoFenceCircle.strokeWidth = 3;
geoFenceCircle.strokeColor = [UIColor orangeColor];
geoFenceCircle.map = mapView; // Add it to the map.

//Updating code for Swift 5.3

 let circle = GMSCircle(position: position, radius:10)
 circle.fillColor = .clear
 circle.strokeWidth = 3
 circle.strokeColor = .black
 circle.map = mapView

It behaves very similarly to an MKCircle (overlay) in that it resizes with the zoom level of the map, etc. Please disregard the blue circle in the center; that's the user location shown on the map view, and I just used the same coordinate for the center point of the GMSCircle.

Super easy. Check out the images:

One zoom level:

And here, we're zoomed out a bit: