How to fit bounds for coordinate array with google maps sdk for iOS? - google-maps-sdk-ios

Question

How to fit bounds for coordinate array with google maps sdk for iOS?
I need to zoom map for 4 visible markers.

Answer 1

Here's my solution for this problem. Building a GMSCoordinateBounds object by multiple coordinates.
- (void)focusMapToShowAllMarkers {
CLLocationCoordinate2D myLocation = ((GMSMarker *)_markers.firstObject).position;
GMSCoordinateBounds *bounds = [[GMSCoordinateBounds alloc] initWithCoordinate:myLocation coordinate:myLocation];
for (GMSMarker *marker in _markers)
bounds = [bounds includingCoordinate:marker.position];
[_mapView animateWithCameraUpdate:[GMSCameraUpdate fitBounds:bounds withPadding:15.0f]];
}
Updated answer: Since GMSMapView markers property is deprecated, you should save all markers in your own array.
updated swift 3 answer:
func focusMapToShowAllMarkers() {
let firstLocation = (markers.first as GMSMarker).position
var bounds = GMSCoordinateBoundsWithCoordinate(firstLocation, coordinate: firstLocation)
for marker in markers {
bounds = bounds.includingCoordinate(marker.position)
}
let update = GMSCameraUpdate.fitBounds(bounds, withPadding: CGFloat(15))
self.mapView.animate(cameraUpdate: update)
}

Answer 2

Swift 3.0 version of Lirik's answer:
func focusMapToShowAllMarkers() {
let myLocation: CLLocationCoordinate2D = self.markers.first!.position
var bounds: GMSCoordinateBounds = GMSCoordinateBounds(coordinate: myLocation, coordinate: myLocation)
for marker in self.markers {
bounds = bounds.includingCoordinate(marker.position)
self.mapView.animate(with: GMSCameraUpdate.fit(bounds, withPadding: 15.0))
}
}
And here's my own way:
func focusMapToShowMarkers(markers: [GMSMarker]) {
guard let currentUserLocation = self.locationManager.location?.coordinate else {
return
}
var bounds: GMSCoordinateBounds = GMSCoordinateBounds(coordinate: currentUserLocation,
coordinate: currentUserLocation)
_ = markers.map {
bounds = bounds.includingCoordinate($0.position)
self.mapView.animate(with: GMSCameraUpdate.fit(bounds, withPadding: 15.0))
}
}
And you can call my function above like so:
self.focusMapToShowMarkers(markers: [self.myLocationMarker, currentPokemonMarker])

Answer 3

Swift 5 version of Lirik's answer:
func focusMapToShowAllMarkers() {
if arrMarkers.count > 0 {
let firstLocation = (arrMarkers.first!).position
var bounds = GMSCoordinateBounds(coordinate: firstLocation, coordinate: firstLocation)
for marker in arrMarkers {
bounds = bounds.includingCoordinate(marker.position)
}
let update = GMSCameraUpdate.fit(bounds, withPadding: CGFloat(15))
self.mapView.animate(with: update)
}
}

Answer 4

For time being, Google has finally implemented the GMSCoordinateBounds,
you can make use of it with GMSCameraUpdate.
For details, please check the official reference.

Answer 5

We can simplify this quite a bit, with code such as the following:
extension Array where Element: GMSMarker {
func encompassingCoordinateBounds() -> GMSCoordinateBounds {
reduce(GMSCoordinateBounds(), { $0.includingCoordinate($1.position) })
}
}
The call site would like:
let markers = [GMSMarker]()
let encompassingCoordinateBounds = markers.encompassingCoordinateBounds()