How to allow user to place markers on map?

Question

I have this little question about markers. What should I do to let user place his own marker on my google maps based app?

Answer 1

There are multiple ways you can do this. One of them is to add a marker when the user long presses on the map. To detect long presses, implement this delegate method:

func mapView(_ mapView: GMSMapView, didLongPressAt coordinate: CLLocationCoordinate2D) {
    let marker = GMSMarker(position: coordinate)
    // marker.isDraggable = true
    // marker.appearAnimation = kGMSMarkerAnimationPop
    marker.map = mapView
    // marker.icon = GMSMarker.markerImage(with: UIColor.blue)
}

The commented-out lines are optional as they are just setting custom attributes of the marker. There are lots more that you can customize.

Also, if you haven't done so already, add GMSMapViewDelegate to your view controller class' declaration:

class YourViewController: UIViewController, GMSMapViewDelegate {

and assign self to the delegate property:

    let camera = GMSCameraPosition.camera(withLatitude: 0, longitude: 0, zoom: 3)
    let mapView = GMSMapView.map(withFrame: CGRect.zero, camera: camera)
    mapView.isMyLocationEnabled = true
    view = mapView

    mapView.delegate = self // add this line!

Alternatively, you can add markers when other events happen. For example, you can add a marker when the user taps on a UIBarBUttonItem or a UIButton. It's all up to you! But the process of adding a button is basically these two lines:

let marker = GMSMarker(position: coordinate)
marker.map = mapView 
// mapView is the map that you want to add the marker to. If you are doing this outside a delegate method, use self.view

You can also consider adding the markers to a collection so you can modify them later.