Add onUserTrackingModeChanged modifier to MapView.

Author: scottrhoyt

Sources/MapLibreSwiftUI/MapView.swift

@@ -33,6 +33,7 @@ public struct MapView<T: MapViewHostViewController>: UIViewControllerRepresentab
     var gestures = [MapGesture]()
 
     var onStyleLoaded: ((MLNStyle) -> Void)?
+    var onUserTrackingModeChanged: ((MLNUserTrackingMode, Bool) -> Void)?
     var onViewProxyChanged: ((MapViewProxy) -> Void)?
     var proxyUpdateMode: ProxyUpdateMode?
 
@@ -105,6 +106,9 @@ public struct MapView<T: MapViewHostViewController>: UIViewControllerRepresentab
         // Link the style loaded to the coordinator that emits the delegate event.
         context.coordinator.onStyleLoaded = onStyleLoaded
 
+        // Link the user tracking change to the coordinator that emits the delegate event.
+        context.coordinator.onUserTrackingModeChange = onUserTrackingModeChanged
+
         // Add all gesture recognizers
         for gesture in gestures {
             registerGesture(controller.mapView, context, gesture: gesture)

Sources/MapLibreSwiftUI/MapViewCoordinator.swift

@@ -44,6 +44,7 @@ MLNMapViewDelegate {
     var cameraUpdateContinuation: CheckedContinuation<Void, Never>?
 
     var onStyleLoaded: ((MLNStyle) -> Void)?
+    var onUserTrackingModeChange: ((MLNUserTrackingMode, Bool) -> Void)?
     var onGesture: (MLNMapView, UIGestureRecognizer) -> Void
     var onViewProxyChanged: (MapViewProxy) -> Void
     var proxyUpdateMode: ProxyUpdateMode
@@ -438,6 +439,10 @@ MLNMapViewDelegate {
         }
     }
 
+    public func mapView(_: MLNMapView, didChange mode: MLNUserTrackingMode, animated: Bool) {
+        onUserTrackingModeChange?(mode, animated)
+    }
+
     // MARK: MapViewProxy
 
     @MainActor private func updateViewProxy(mapView: MLNMapView, reason: MLNCameraChangeReason) {

Sources/MapLibreSwiftUI/MapViewModifiers.swift

@@ -14,6 +14,12 @@ public extension MapView {
         return newMapView
     }
 
+    func onUserTrackingModeChanged(_ perform: @escaping (MLNUserTrackingMode, Bool) -> Void) -> MapView {
+        var newMapView = self
+        newMapView.onUserTrackingModeChanged = perform
+        return newMapView
+    }
+
     /// Allows you to set properties of the underlying MLNMapView directly
     /// in cases where these have not been ported to DSL yet.
     /// Use this function to modify various properties of the MLNMapView instance.