metodi mappa

  func updateMap() {

        //posizione dell'utente
        var currentLocation: CLLocation!

        if( CLLocationManager.authorizationStatus() == .authorizedWhenInUse ||
            CLLocationManager.authorizationStatus() ==  .authorizedAlways){

            currentLocation = locationManager.location

        }

        let location = CLLocationCoordinate2D(latitude: currentLocation.coordinate.latitude, longitude: currentLocation.coordinate.longitude)

        let region = MKCoordinateRegion(center: location, span: MKCoordinateSpan(latitudeDelta: 0.008, longitudeDelta: 0.008))

        self.vistaMappa.setRegion(region, animated: true)

        self.navigationController!.navigationBar.topItem!.title = "Mappa scuole"


        let apps = DownloadManager.shared.localArra

        for app in apps {

            let location = CLLocationCoordinate2D(latitude: CLLocationDegrees(Float(app.latScuola)), longitude : CLLocationDegrees(Float(app.lngScuola)))

            scuoleLocations.append(Pin(pinTitle: app.nomeScuola, pinSubTitle: app.indirizzoScuola, location: location))
        }
        //print(scuoleLocations)
        self.vistaMappa.addAnnotations(scuoleLocations)
    }

    func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {

        if annotation is MKUserLocation {
            return nil
        }
        let annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: "customannotation")
        annotationView.image = UIImage(named: "marker")
        annotationView.canShowCallout = true

        let btn = UIButton(type: .detailDisclosure)
        annotationView.rightCalloutAccessoryView = btn

        return annotationView
    }


    func mapView(_ mapView: MKMapView,
                 annotationView view: MKAnnotationView,
                 calloutAccessoryControlTapped control: UIControl)
    {
        performSegue(withIdentifier: "toDettaglio", sender: self)
    }




    //implemento il protocollo con locationManager
    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {

        //verifico se posso recuperare le coordinate (e in caso le recupero)
        if let lat = locations.last?.coordinate.latitude, let long = locations.last?.coordinate.longitude {
            print("\(lat),\(long)")
        } else {
            print("Nessuna coordinata")
        }
    }

    //implemento monitoraggio errore
    func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
        print(error)
    }

    //estrapolo dalle coordinate il nome della città o luogo in cui l'utente si trova
    func lookUpCurrentLocation(completionHandler: @escaping (CLPlacemark?) -> Void ) {

        // recupero direttamente da locationManager le ultime coordinate memorizzate
        if let lastLocation = self.locationManager.location {

            //creo un'istanza di CLGeocoder per il reversing delle coordinate
            let geocoder = CLGeocoder()

            // Look up the location and pass it to the completion handler
            geocoder.reverseGeocodeLocation(lastLocation, completionHandler: { (placemarks, error) in
                if error == nil {
                    let firstLocation = placemarks?[0]
                    completionHandler(firstLocation)
                }
                else {
                    // An error occurred during geocoding.
                    completionHandler(nil)
                }
            })
        }
        else {
            // No location was available.
            completionHandler(nil)
        }
    }