Weird behavior of custom annotations views - swift

Question

I've built the same code in SwiftUI and Storyboard and I get the same weird issues.
Whenever I run and go to background and back to foreground, the custom views are lost.
Whenever I zoom-drag far (say 10km), I also lose the non-picture-holding pin, eg "Pencil".
I'm not sure where I've gone amiss, except maybe that I'd need to separate my pins per annotation view "type" (with a given picture, with text...) and set a different reuse identifier based on that, but it sounds weird given I'm not actually creating anything new (only setting properties of the base MKAnnotationView class).
Using the UIKit version as reference:
import UIKit
import MapKit
class MapViewController: UIViewController {
#IBOutlet weak var mapView: MKMapView!
let cityMapManager = CityMapManager()
let cityMapViewDelegate = CityMapViewDelegate()
let places: [Place] = [Place(name: "Cathedral", location: .init(latitude: 50.640364, longitude: 3.062058))]
override func viewDidLoad() {
super.viewDidLoad()
mapView.setRegion(MKCoordinateRegion(center: CLLocationCoordinate2D(latitude: 50.640364, longitude: 3.062058), latitudinalMeters: 500.0, longitudinalMeters: 500.0), animated: false)
mapView.showsUserLocation = true
mapView.showsScale = true
mapView.delegate = cityMapViewDelegate
annotateLocalPOI(map: mapView)
}
private func annotateLocalPOI(map: MKMapView) {
var annotation = MKPointAnnotation()
annotation.title = "Red Pin"
annotation.subtitle = "I'm a pin and I'm red. Maybe, or not."
annotation.coordinate = CLLocationCoordinate2D(latitude: 50.64, longitude: 3.06)
// add the annotation to the map (will use red pin, mapView:viewFor: allows changing the display)
map.addAnnotation(annotation)
annotation = MKPointAnnotation()
annotation.title = "Pencil"
annotation.subtitle = "Will not display"
annotation.coordinate = CLLocationCoordinate2D(latitude: 50.642, longitude: 3.059)
map.addAnnotation(annotation)
}
}
struct Place: Identifiable {
let id: UUID = UUID()
let name: String
let location: CLLocationCoordinate2D
}
class CityMapViewDelegate: NSObject, MKMapViewDelegate {
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
guard annotation is MKPointAnnotation else { return nil }
let identifier = "Annotation"
var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: identifier)
if annotationView == nil {
annotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: identifier)
annotationView!.canShowCallout = true
if annotation.title == "Red Pin" {
let pinImage = UIImage(systemName: "timelapse")
annotationView?.image = pinImage
}
if annotation.title == "Pencil" {
// this overrules any subtitle available
annotationView?.detailCalloutAccessoryView = UIImageView(image: UIImage(systemName: "pencil"))
}
} else {
// reset
annotationView?.detailCalloutAccessoryView = nil
annotationView?.image = nil
// set it up again
annotationView?.annotation = annotation
if annotation.title == "Red Pin" {
let pinImage = UIImage(systemName: "timelapse")
annotationView?.image = pinImage
}
if annotation.title == "Pencil" {
// this overrules any subtitle available
annotationView?.detailCalloutAccessoryView = UIImageView(image: UIImage(systemName: "pencil"))
}
}
return annotationView
}
}
class CityLocationManagerDelegate: NSObject, CLLocationManagerDelegate {
var locationStatus = "Status not determined"
var locationFixFound = false
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
// We've (at least once) gone under a certain minimum accuracy required to consider we have a "fix"
// we could use that to reflect that information on the UI (color, shape...)
if !locationFixFound {
for location in locations {
if location.horizontalAccuracy < 25.0 {
locationFixFound = true
}
}
}
}
func locationManager(_ manager: CLLocationManager,
didFailWithError error: Error) {
manager.stopUpdatingLocation()
print("Location manager stopped due to error: \(error)")
}
func locationManager(_ manager: CLLocationManager,
didChangeAuthorization status: CLAuthorizationStatus) {
print("Authorization Status changed")
var shouldRequestLocationUpdates = false
switch status {
case CLAuthorizationStatus.restricted:
locationStatus = "Restricted Access to location"
case CLAuthorizationStatus.denied:
locationStatus = "User denied access to location"
case CLAuthorizationStatus.notDetermined:
locationStatus = "Status not determined"
default:
locationStatus = "Allowed to location Access"
shouldRequestLocationUpdates = true
}
if (shouldRequestLocationUpdates == true) {
NSLog("Location to Allowed")
// Start location services
manager.startUpdatingLocation()
} else {
NSLog("Denied access: \(locationStatus)")
}
}
}
struct CityMapManager {
let locationDelegate: CLLocationManagerDelegate
let locationManager: CLLocationManager
init() {
locationDelegate = CityLocationManagerDelegate()
locationManager = CLLocationManager()
locationManager.delegate = locationDelegate
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.requestWhenInUseAuthorization()
locationManager.requestAlwaysAuthorization()
}
}
and a storyboard that holds a fullscreen map within a class set to MapViewController.