SwiftUI / MapKit Annotation Selection and Navigation - ios

Question

I currently have a SwiftUI view that displays a map full of pins. The map has a delegate which can determine when a pin is selected and get the custom object associated with that pin.
The problem is that once the delegate determines that the pin has been selected, I need my SwiftUI view to navigate/push to a detail page with the custom object that the delegate retrieved.
The best comparison I can think of is trying to treat the selected annotation as a navigation link button for the main view.
How do I communicate from the map delegate to the SwiftUI view?
import SwiftUI
import MapKit
/// The SwiftUI view I am referring to
struct ContentView: View {
var body: some View {
ZStack {
MapView()
}
.edgesIgnoringSafeArea(.all)
}
}
/// The custom object I am referring to
class LandmarkAnnotation: NSObject, MKAnnotation {
let title: String?
let subtitle: String?
let coordinate: CLLocationCoordinate2D
init(title: String?,
subtitle: String?,
coordinate: CLLocationCoordinate2D) {
self.title = title
self.subtitle = subtitle
self.coordinate = coordinate
}
}
/// The delegate I am referring to
class MapViewCoordinator: NSObject, MKMapViewDelegate {
var mapViewController: MapView
init(_ control: MapView) {
self.mapViewController = control
}
func mapView(_ mapView: MKMapView, viewFor
annotation: MKAnnotation) -> MKAnnotationView?{
...
return annotationView
}
func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
let circle = MKCircleRenderer(overlay: overlay)
...
return circle
}
/// This is where the delegate gets the object for the selected annotation
func mapView(_ mapView: MKMapView, didSelect view: MKAnnotationView) {
if let v = view.annotation as? LandmarkAnnotation {
print(v.coordinate)
}
}
}
struct MapView: UIViewRepresentable {
var markers: [CLLocationCoordinate2D] = [CLLocationCoordinate2D(
latitude: 34.055404, longitude: -118.249278),CLLocationCoordinate2D(
latitude: 34.054097, longitude: -118.249664), CLLocationCoordinate2D(latitude: 34.053786, longitude: -118.247636)]
var convertedMarkers: [LandmarkAnnotation] = []
init() {
convertedMarkers = cordToMark(locations: self.markers)
}
func makeUIView(context: Context) -> MKMapView{
MKMapView(frame: .zero)
}
func cordToMark(locations: [CLLocationCoordinate2D]) -> [LandmarkAnnotation] {
var marks: [LandmarkAnnotation] = []
for cord in locations {
let mark = LandmarkAnnotation(title: "Test", subtitle: "Sub", coordinate: cord)
marks.append(mark)
}
return marks
}
func makeCoordinator() -> MapViewCoordinator{
MapViewCoordinator(self)
}
func updateUIView(_ view: MKMapView, context: Context){
let coordinate = CLLocationCoordinate2D(
latitude: 34.0537767, longitude: -118.248)
let mapCamera = MKMapCamera()
mapCamera.centerCoordinate = coordinate
mapCamera.pitch = 10
mapCamera.altitude = 3000
view.camera = mapCamera
view.mapType = .mutedStandard
view.delegate = context.coordinator
view.addAnnotations(self.convertedMarkers)
let radiusCircle = MKCircle(center: CLLocationCoordinate2D(
latitude: 34.0537767, longitude: -118.248), radius: 300 as CLLocationDistance)
view.addOverlay(radiusCircle)
let locationCircle = MKCircle(center: CLLocationCoordinate2D(
latitude: 34.0537767, longitude: -118.248), radius: 3 as CLLocationDistance)
view.addOverlay(locationCircle)
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
.environment(\.colorScheme, .light)
}
}
Here is an image of the map that is displayed in the simulator

Answer 1

Here is an idea (scratch)
add a callback to representable
struct MapView: UIViewRepresentable {
var didSelect: (LandmarkAnnotation) -> () // callback
so in ContentView
ZStack {
MapView() { annotation in
// store/pass annotation somewhere, and
// activate navigation link here, eg. via isActive or selection
}
}
activate callback in delegate
func mapView(_ mapView: MKMapView, didSelect view: MKAnnotationView) {
if let v = view.annotation as? LandmarkAnnotation {
print(v.coordinate)
self.mapViewController.didSelect(v) // << here !!
}
}