How show map annotations when map span will be 0.1? - swift

Question

How show map annotations when map span will be 0.1?
I want map pins to not show until map span is <= 0.1
struct City: Identifiable {
let id = UUID()
let name: String
let coordinate: CLLocationCoordinate2D
}
struct ContentView: View {
#State private var region = MKCoordinateRegion(center: CLLocationCoordinate2D(latitude: 51.507222, longitude: -0.1275), span: MKCoordinateSpan(latitudeDelta: 10, longitudeDelta: 10))
let annotations = [
City(name: "London", coordinate: CLLocationCoordinate2D(latitude: 51.507222, longitude: -0.1275)),
City(name: "Paris", coordinate: CLLocationCoordinate2D(latitude: 48.8567, longitude: 2.3508)),
City(name: "Rome", coordinate: CLLocationCoordinate2D(latitude: 41.9, longitude: 12.5)),
City(name: "Washington DC", coordinate: CLLocationCoordinate2D(latitude: 38.895111, longitude: -77.036667))
]
var body: some View {
Map(coordinateRegion: $region, annotationItems: annotations) {
MapPin(coordinate: $0.coordinate)
}
.frame(width: 400, height: 300)
}
}
How can this be done?

Answer 1

You can't with MapPin because it's a type of protocol not View. Instead of it you can use MapAnnotation. Since your region parameter is binding the view, you can check map span and show/hide your annotation like this;
Map(coordinateRegion: $region, annotationItems: annotations) {
MapAnnotation(coordinate: $0.coordinate) {
// Use whatever value instead of 2.5
if region.span.latitudeDelta < 2.5 {
Image(systemName: "mappin")
.resizable()
.frame(width: 18, height: 36)
.foregroundColor(Color.red)
} else {
EmptyView()
}
}
}
.frame(width: 400, height: 300)