UISearchController with Google Maps using Swift

Question

UISearchController with Google Maps using Swift

I am trying to create a screen on which a Google map will be displayed, covering the entire screen, and a button at the top showing the selected address (where the marker indicates). And I want, when a user clicks on this button, to present a UISearchBar where he can search for locations using the Google Places API.

I ran the following tutorial: https://www.youtube.com/watch?v=gRQUoHleCGM

Unfortunately, in my case, the search bar does not appear (although the background is darkened when I click the button).

Here are some screenshots before you click and after.

And this is the code of my view controller.

class ChooseLocationViewController: UIViewController, GMSMapViewDelegate, UISearchBarDelegate, UISearchControllerDelegate {

    let geocoder = GMSGeocoder()
    var mapView: GMSMapView = GMSMapView.mapWithFrame(CGRectZero, camera:GMSCameraPosition.cameraWithLatitude(51.515339, longitude: -0.141838, zoom: 16))
    var addressButton: UIButton = UIButton()

    let locationManager = CLLocationManager()

    override func viewDidLoad() {
        super.viewDidLoad()

        mapView.delegate = self

        let marker = UIImageView(frame: CGRect(x: 20, y: 20, width: 50, height: 50))
        marker.image = UIImage(named: "default-marker")
        marker.center.x = self.view.center.x
        marker.center.y = self.view.center.y - (self.navigationController?.navigationBar.frame.size.height)!

        addressButton = UIButton(frame: CGRect(x: 20, y: 20, width: self.view.frame.size.width - 25, height: 47))
        addressButton.center.x = self.view.center.x
        addressButton.backgroundColor = UIColor(red: 248/255, green: 248/255, blue: 248/255, alpha: 1.0)
        addressButton.layer.borderColor = UIColor(red: 178/255, green: 178/255, blue: 178/255, alpha: 1.0).CGColor
        addressButton.layer.borderWidth = 1.0
        addressButton.layer.cornerRadius = 5
        addressButton.setTitleColor(UIColor(red: 68/255, green: 68/255, blue: 68/255, alpha: 1.0), forState: .Normal)
        addressButton.titleLabel?.font = UIFont.systemFontOfSize(13)
        addressButton.addTarget(self, action: "showLocationSearch", forControlEvents: .TouchDown)

        self.view = mapView
        self.view.addSubview(marker)
        self.view.addSubview(addressButton)
    }

    func showLocationSearch() {
        let searchController = UISearchController(searchResultsController: nil)
        searchController.delegate = self
        searchController.searchBar.delegate = self
        self.presentViewController(searchController, animated: true, completion: nil)
    }

    func willPresentSearchController(searchController: UISearchController) {
        self.navigationController?.extendedLayoutIncludesOpaqueBars = true
    }

    func willDismissSearchController(searchController: UISearchController) {
        self.navigationController?.extendedLayoutIncludesOpaqueBars = false
    }

    func mapView(mapView: GMSMapView, idleAtCameraPosition position: GMSCameraPosition) {
        let coordinate = position.target
        geocoder.reverseGeocodeCoordinate(coordinate) { response, error in
            if let address = response?.firstResult() {
                if let lines = address.lines {
                    if (lines.count > 0) {
                        self.addressButton.setTitle(lines[0], forState: .Normal)
                    }
                }
            }
        }
    }
}