fix: initialize view listeners on platform view creation (#342)

Make sure view event listeners are initialized as soon as view is created to avoid missing early view events.

Author: jokerttu

android/src/main/kotlin/com/google/maps/flutter/navigation/GoogleMapsAutoViewMessageHandler.kt

@@ -378,8 +378,8 @@ class GoogleMapsAutoViewMessageHandler(private val viewRegistry: GoogleMapsViewR
     getView().clearCircles()
   }
 
-  override fun registerOnCameraChangedListener() {
-    getView().registerOnCameraChangedListener()
+  override fun enableOnCameraChangedEvents() {
+    getView().enableOnCameraChangedEvents()
   }
 
   override fun isAutoScreenAvailable(): Boolean {

android/src/main/kotlin/com/google/maps/flutter/navigation/GoogleMapsBaseMapView.kt

@@ -59,7 +59,7 @@ abstract class GoogleMapsBaseMapView(
 
   // Nullable variable to hold the callback function
   private var _mapReadyCallback: ((Result<Unit>) -> Unit)? = null
-  private var _loadedCallbackPending = false
+  private var _pendingCameraEventsListenerSetup = false
 
   /// Default values for UI features.
   private var _consumeMyLocationButtonClickEventsEnabled: Boolean = false
@@ -212,6 +212,10 @@ abstract class GoogleMapsBaseMapView(
           }
         }
       )
+
+    if (_pendingCameraEventsListenerSetup) {
+      setOnCameraChangedListeners()
+    }
   }
 
   // Installs a custom invalidator for the map view.
@@ -910,7 +914,17 @@ abstract class GoogleMapsBaseMapView(
     _circles.clear()
   }
 
-  fun registerOnCameraChangedListener() {
+  fun enableOnCameraChangedEvents() {
+    // If map is already initialized, set the listeners.
+    // Otherwise, the listeners will be set in the initListeners method.
+    if (_map != null) {
+      setOnCameraChangedListeners()
+    } else {
+      _pendingCameraEventsListenerSetup = true
+    }
+  }
+
+  fun setOnCameraChangedListeners() {
     getMap().setOnCameraMoveStartedListener { reason ->
       val event =
         when (reason) {
@@ -943,6 +957,7 @@ abstract class GoogleMapsBaseMapView(
         position,
       ) {}
     }
+    _pendingCameraEventsListenerSetup = false
   }
 
   fun setPadding(padding: MapPaddingDto) {

android/src/main/kotlin/com/google/maps/flutter/navigation/GoogleMapsViewMessageHandler.kt

@@ -488,8 +488,8 @@ class GoogleMapsViewMessageHandler(private val viewRegistry: GoogleMapsViewRegis
     getView(viewId.toInt()).clearCircles()
   }
 
-  override fun registerOnCameraChangedListener(viewId: Long) {
-    getView(viewId.toInt()).registerOnCameraChangedListener()
+  override fun enableOnCameraChangedEvents(viewId: Long) {
+    getView(viewId.toInt()).enableOnCameraChangedEvents()
   }
 
   override fun setPadding(viewId: Long, padding: MapPaddingDto) {

android/src/main/kotlin/com/google/maps/flutter/navigation/ImageRegistry.kt

@@ -27,6 +27,8 @@ class ImageRegistry {
 
   private var isMapViewInitialized = false
 
+  // BitmapDescriptor cannot be created if map view is not initialized yet.
+  // When map view is initialized, all queued bitmaps are processed and added to the registry.
   fun mapViewInitializationComplete() {
     isMapViewInitialized = true
     bitmapQueue.forEach {
@@ -47,7 +49,7 @@ class ImageRegistry {
     val bitmap = createBitmap(bytes, imagePixelRatio, density, width, height)
 
     if (!isMapViewInitialized) {
-      // BitmapDescriptor cannot me created if map view is not initialized yet.
+      // BitmapDescriptor cannot be created if map view is not initialized yet.
       // Add to queue to make it later.
       bitmapQueue.add(QueuedBitmap(imageId, bitmap, imagePixelRatio, width, height))
     } else {

android/src/main/kotlin/com/google/maps/flutter/navigation/messages.g.kt

@@ -2230,7 +2230,7 @@ interface MapViewApi {
 
   fun clearCircles(viewId: Long)
 
-  fun registerOnCameraChangedListener(viewId: Long)
+  fun enableOnCameraChangedEvents(viewId: Long)
 
   fun setPadding(viewId: Long, padding: MapPaddingDto)
 
@@ -4522,7 +4522,7 @@ interface MapViewApi {
         val channel =
           BasicMessageChannel<Any?>(
             binaryMessenger,
-            "dev.flutter.pigeon.google_navigation_flutter.MapViewApi.registerOnCameraChangedListener",
+            "dev.flutter.pigeon.google_navigation_flutter.MapViewApi.enableOnCameraChangedEvents",
             codec,
           )
         if (api != null) {
@@ -4531,7 +4531,7 @@ interface MapViewApi {
             val viewIdArg = args[0].let { if (it is Int) it.toLong() else it as Long }
             var wrapped: List<Any?>
             try {
-              api.registerOnCameraChangedListener(viewIdArg)
+              api.enableOnCameraChangedEvents(viewIdArg)
               wrapped = listOf<Any?>(null)
             } catch (exception: Throwable) {
               wrapped = wrapError(exception)
@@ -6630,7 +6630,7 @@ interface AutoMapViewApi {
 
   fun clearCircles()
 
-  fun registerOnCameraChangedListener()
+  fun enableOnCameraChangedEvents()
 
   fun isAutoScreenAvailable(): Boolean
 
@@ -8297,14 +8297,14 @@ interface AutoMapViewApi {
         val channel =
           BasicMessageChannel<Any?>(
             binaryMessenger,
-            "dev.flutter.pigeon.google_navigation_flutter.AutoMapViewApi.registerOnCameraChangedListener",
+            "dev.flutter.pigeon.google_navigation_flutter.AutoMapViewApi.enableOnCameraChangedEvents",
             codec,
           )
         if (api != null) {
           channel.setMessageHandler { _, reply ->
             var wrapped: List<Any?>
             try {
-              api.registerOnCameraChangedListener()
+              api.enableOnCameraChangedEvents()
               wrapped = listOf<Any?>(null)
             } catch (exception: Throwable) {
               wrapped = wrapError(exception)

example/lib/pages/navigation.dart

@@ -1405,12 +1405,14 @@ class _NavigationPageState extends ExamplePageState<NavigationPage> {
                       ElevatedButton(
                         onPressed: _pauseSimulation,
                         child: const Text('Pause simulation'),
-                      ),
-                    if (_simulationState == SimulationState.paused)
+                      )
+                    else if (_simulationState == SimulationState.paused)
                       ElevatedButton(
                         onPressed: _resumeSimulation,
                         child: const Text('Resume simulation'),
-                      ),
+                      )
+                    else
+                      Text(_simulationState.description),
                   ],
                 ),
                 const SizedBox(height: 10)
@@ -1771,3 +1773,21 @@ class _NavigationPageState extends ExamplePageState<NavigationPage> {
     }
   }
 }
+
+/// Returns a human-readable description of the [SimulationState].
+extension SimulationStateDescription on SimulationState {
+  String get description {
+    switch (this) {
+      case SimulationState.unknown:
+        return 'Unknown simulation state';
+      case SimulationState.running:
+        return 'Running';
+      case SimulationState.runningOutdated:
+        return 'Running with outdated route';
+      case SimulationState.paused:
+        return 'Paused';
+      case SimulationState.notRunning:
+        return 'Not running';
+    }
+  }
+}

ios/google_navigation_flutter/Sources/google_navigation_flutter/GoogleMapsAutoViewMessageHandler.swift

@@ -464,8 +464,8 @@ class GoogleMapsAutoViewMessageHandler: AutoMapViewApi {
     try getView().setMaxZoomPreference(maxZoomPreference: Float(maxZoomPreference))
   }
 
-  func registerOnCameraChangedListener() throws {
-    try getView().registerOnCameraChangedListener()
+  func enableOnCameraChangedEvents() throws {
+    try getView().enableOnCameraChangedEvents()
   }
 
   func isAutoScreenAvailable() throws -> Bool {

ios/google_navigation_flutter/Sources/google_navigation_flutter/GoogleMapsNavigationView.swift

@@ -868,7 +868,7 @@ public class GoogleMapsNavigationView: NSObject, FlutterPlatformView, ViewSettle
     _consumeMyLocationButtonClickEventsEnabled
   }
 
-  func registerOnCameraChangedListener() {
+  func enableOnCameraChangedEvents() {
     // Camera listeners cannot be controlled at runtime, so use this
     // boolean to control if camera changes are sent over the event channel.
     _listenCameraChanges = true

ios/google_navigation_flutter/Sources/google_navigation_flutter/GoogleMapsNavigationViewMessageHandler.swift

@@ -548,8 +548,8 @@ class GoogleMapsNavigationViewMessageHandler: MapViewApi {
     try getView(viewId).setMaxZoomPreference(maxZoomPreference: Float(maxZoomPreference))
   }
 
-  func registerOnCameraChangedListener(viewId: Int64) throws {
-    try getView(viewId).registerOnCameraChangedListener()
+  func enableOnCameraChangedEvents(viewId: Int64) throws {
+    try getView(viewId).enableOnCameraChangedEvents()
   }
 
   func setPadding(viewId: Int64, padding: MapPaddingDto) throws {

ios/google_navigation_flutter/Sources/google_navigation_flutter/messages.g.swift

@@ -2042,7 +2042,7 @@ protocol MapViewApi {
   func updateCircles(viewId: Int64, circles: [CircleDto]) throws -> [CircleDto]
   func removeCircles(viewId: Int64, circles: [CircleDto]) throws
   func clearCircles(viewId: Int64) throws
-  func registerOnCameraChangedListener(viewId: Int64) throws
+  func enableOnCameraChangedEvents(viewId: Int64) throws
   func setPadding(viewId: Int64, padding: MapPaddingDto) throws
   func getPadding(viewId: Int64) throws -> MapPaddingDto
 }
@@ -3761,23 +3761,22 @@ class MapViewApiSetup {
     } else {
       clearCirclesChannel.setMessageHandler(nil)
     }
-    let registerOnCameraChangedListenerChannel = FlutterBasicMessageChannel(
-      name:
-        "dev.flutter.pigeon.google_navigation_flutter.MapViewApi.registerOnCameraChangedListener",
+    let enableOnCameraChangedEventsChannel = FlutterBasicMessageChannel(
+      name: "dev.flutter.pigeon.google_navigation_flutter.MapViewApi.enableOnCameraChangedEvents",
       binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
-      registerOnCameraChangedListenerChannel.setMessageHandler { message, reply in
+      enableOnCameraChangedEventsChannel.setMessageHandler { message, reply in
         let args = message as! [Any?]
         let viewIdArg = args[0] is Int64 ? args[0] as! Int64 : Int64(args[0] as! Int32)
         do {
-          try api.registerOnCameraChangedListener(viewId: viewIdArg)
+          try api.enableOnCameraChangedEvents(viewId: viewIdArg)
           reply(wrapResult(nil))
         } catch {
           reply(wrapError(error))
         }
       }
     } else {
-      registerOnCameraChangedListenerChannel.setMessageHandler(nil)
+      enableOnCameraChangedEventsChannel.setMessageHandler(nil)
     }
     let setPaddingChannel = FlutterBasicMessageChannel(
       name: "dev.flutter.pigeon.google_navigation_flutter.MapViewApi.setPadding",
@@ -5630,7 +5629,7 @@ protocol AutoMapViewApi {
   func updateCircles(circles: [CircleDto]) throws -> [CircleDto]
   func removeCircles(circles: [CircleDto]) throws
   func clearCircles() throws
-  func registerOnCameraChangedListener() throws
+  func enableOnCameraChangedEvents() throws
   func isAutoScreenAvailable() throws -> Bool
   func setPadding(padding: MapPaddingDto) throws
   func getPadding() throws -> MapPaddingDto
@@ -6855,21 +6854,21 @@ class AutoMapViewApiSetup {
     } else {
       clearCirclesChannel.setMessageHandler(nil)
     }
-    let registerOnCameraChangedListenerChannel = FlutterBasicMessageChannel(
+    let enableOnCameraChangedEventsChannel = FlutterBasicMessageChannel(
       name:
-        "dev.flutter.pigeon.google_navigation_flutter.AutoMapViewApi.registerOnCameraChangedListener",
+        "dev.flutter.pigeon.google_navigation_flutter.AutoMapViewApi.enableOnCameraChangedEvents",
       binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
-      registerOnCameraChangedListenerChannel.setMessageHandler { _, reply in
+      enableOnCameraChangedEventsChannel.setMessageHandler { _, reply in
         do {
-          try api.registerOnCameraChangedListener()
+          try api.enableOnCameraChangedEvents()
           reply(wrapResult(nil))
         } catch {
           reply(wrapError(error))
         }
       }
     } else {
-      registerOnCameraChangedListenerChannel.setMessageHandler(nil)
+      enableOnCameraChangedEventsChannel.setMessageHandler(nil)
     }
     let isAutoScreenAvailableChannel = FlutterBasicMessageChannel(
       name: "dev.flutter.pigeon.google_navigation_flutter.AutoMapViewApi.isAutoScreenAvailable",