[Feature] Android secondary position stream for foreground notification updates

geolocator_android/android/src/main/java/com/baseflow/geolocator/GeolocatorPlugin.java

@@ -31,6 +31,8 @@ public class GeolocatorPlugin implements FlutterPlugin, ActivityAware {
   @Nullable private MethodCallHandlerImpl methodCallHandler;
 
   @Nullable private StreamHandlerImpl streamHandler;
+  @Nullable private StreamHandlerImpl streamHandlerFGN;
+
   private final ServiceConnection serviceConnection =
       new ServiceConnection() {
 
@@ -68,9 +70,12 @@ public void onAttachedToEngine(@NonNull FlutterPluginBinding flutterPluginBindin
             this.permissionManager, this.geolocationManager, this.locationAccuracyManager);
     methodCallHandler.startListening(
         flutterPluginBinding.getApplicationContext(), flutterPluginBinding.getBinaryMessenger());
-    streamHandler = new StreamHandlerImpl(this.permissionManager, this.geolocationManager);
+    streamHandler = new StreamHandlerImpl(this.permissionManager, this.geolocationManager, "flutter.baseflow.com/geolocator_updates_android");
     streamHandler.startListening(
         flutterPluginBinding.getApplicationContext(), flutterPluginBinding.getBinaryMessenger());
+    streamHandlerFGN = new StreamHandlerImpl(this.permissionManager, this.geolocationManager, "flutter.baseflow.com/geolocator_updates_android_fgn");
+    streamHandlerFGN.startListening(
+        flutterPluginBinding.getApplicationContext(), flutterPluginBinding.getBinaryMessenger());
 
     locationServiceHandler = new LocationServiceHandlerImpl();
     locationServiceHandler.setContext(flutterPluginBinding.getApplicationContext());
@@ -97,6 +102,9 @@ public void onAttachedToActivity(@NonNull ActivityPluginBinding binding) {
     if (streamHandler != null) {
       streamHandler.setActivity(binding.getActivity());
     }
+    if (streamHandlerFGN != null) {
+      streamHandlerFGN.setActivity(binding.getActivity());
+    }
     if (foregroundLocationService != null) {
       foregroundLocationService.setActivity(pluginBinding.getActivity());
     }
@@ -122,6 +130,9 @@ public void onDetachedFromActivity() {
     if (streamHandler != null) {
       streamHandler.setActivity(null);
     }
+    if (streamHandlerFGN != null) {
+      streamHandlerFGN.setActivity(null);
+    }
     if (foregroundLocationService != null) {
       foregroundLocationService.setActivity(null);
     }
@@ -164,8 +175,8 @@ private void initialize(GeolocatorLocationService service) {
     foregroundLocationService.setGeolocationManager(geolocationManager);
     foregroundLocationService.flutterEngineConnected();
 
-    if (streamHandler != null) {
-      streamHandler.setForegroundLocationService(service);
+    if (streamHandlerFGN != null) {
+      streamHandlerFGN.setForegroundLocationService(service);
     }
   }
 
@@ -178,9 +189,13 @@ private void dispose() {
     }
     if (streamHandler != null) {
       streamHandler.stopListening();
-      streamHandler.setForegroundLocationService(null);
       streamHandler = null;
     }
+    if (streamHandlerFGN != null) {
+      streamHandlerFGN.stopListening();
+      streamHandlerFGN.setForegroundLocationService(null);
+      streamHandlerFGN = null;
+    }
     if (locationServiceHandler != null) {
       locationServiceHandler.setContext(null);
       locationServiceHandler.stopListening();

geolocator_android/android/src/main/java/com/baseflow/geolocator/StreamHandlerImpl.java

@@ -25,6 +25,7 @@ class StreamHandlerImpl implements EventChannel.StreamHandler {
   private static final String TAG = "FlutterGeolocator";
 
   private final PermissionManager permissionManager;
+  private final String eventChannelIdentifier;
 
   @Nullable private EventChannel channel;
   @Nullable private Context context;
@@ -33,9 +34,10 @@ class StreamHandlerImpl implements EventChannel.StreamHandler {
   @Nullable private GeolocationManager geolocationManager;
   @Nullable private LocationClient locationClient;
 
-  public StreamHandlerImpl(PermissionManager permissionManager, GeolocationManager geolocationManager) {
+  public StreamHandlerImpl(PermissionManager permissionManager, GeolocationManager geolocationManager, String eventChannelIdentifier) {
     this.permissionManager = permissionManager;
     this.geolocationManager = geolocationManager;
+    this.eventChannelIdentifier = eventChannelIdentifier;
   }
 
   public void setForegroundLocationService(
@@ -65,7 +67,7 @@ void startListening(Context context, BinaryMessenger messenger) {
       stopListening();
     }
 
-    channel = new EventChannel(messenger, "flutter.baseflow.com/geolocator_updates_android");
+    channel = new EventChannel(messenger, eventChannelIdentifier);
     channel.setStreamHandler(this);
     this.context = context;
   }
@@ -105,11 +107,6 @@ public void onListen(Object arguments, EventChannel.EventSink events) {
       return;
     }
 
-    if (foregroundLocationService == null) {
-      Log.e(TAG, "Location background service has not started correctly");
-      return;
-    }
-
     @SuppressWarnings("unchecked")
     Map<String, Object> map = (Map<String, Object>) arguments;
     boolean forceLocationManager = false;
@@ -125,6 +122,10 @@ public void onListen(Object arguments, EventChannel.EventSink events) {
               (Map<String, Object>) map.get("foregroundNotificationConfig"));
     }
     if (foregroundNotificationOptions != null) {
+      if (foregroundLocationService == null) {
+        Log.e(TAG, "Location background service has not started correctly");
+        return;
+      }
       Log.e(TAG, "Geolocator position updates started using Android foreground service");
       foregroundLocationService.startLocationService(forceLocationManager, locationOptions, events);
       foregroundLocationService.enableBackgroundMode(foregroundNotificationOptions);

geolocator_android/lib/src/geolocator_android.dart

@@ -16,6 +16,11 @@ class GeolocatorAndroid extends GeolocatorPlatform {
   static const _eventChannel =
       EventChannel('flutter.baseflow.com/geolocator_updates_android');
 
+  /// The secondary event channel used to receive [Position] updates from the
+  /// native platform.
+  static const _eventChannelFGN =
+      EventChannel('flutter.baseflow.com/geolocator_updates_android_fgn');
+
   /// The event channel used to receive [LocationServiceStatus] updates from the
   /// native platform.
   static const _serviceStatusEventChannel =
@@ -33,6 +38,7 @@ class GeolocatorAndroid extends GeolocatorPlatform {
   bool forcedLocationManager = false;
 
   Stream<Position>? _positionStream;
+  Stream<Position>? _positionStreamFGN;
   Stream<ServiceStatus>? _serviceStatusStream;
 
   final Uuid _uuid = const Uuid();
@@ -166,21 +172,36 @@ class GeolocatorAndroid extends GeolocatorPlatform {
   Stream<Position> getPositionStream({
     LocationSettings? locationSettings,
   }) {
-    if (_positionStream != null) {
-      return _positionStream!;
+    final bool useForegroundNotification = locationSettings is AndroidSettings
+        ? locationSettings.foregroundNotificationConfig != null
+        : false;
+    if (useForegroundNotification) {
+      if (_positionStreamFGN != null) {
+        return _positionStreamFGN!;
+      }
+    } else {
+      if (_positionStream != null) {
+        return _positionStream!;
+      }
     }
-    var originalStream = _eventChannel.receiveBroadcastStream(
+    var originalStream =
+        (useForegroundNotification ? _eventChannelFGN : _eventChannel)
+            .receiveBroadcastStream(
       locationSettings?.toJson(),
     );
-    var positionStream = _wrapStream(originalStream);
+    var positionStream = _wrapStream(originalStream, useForegroundNotification);
 
     var timeLimit = locationSettings?.timeLimit;
 
     if (timeLimit != null) {
       positionStream = positionStream.timeout(
         timeLimit,
         onTimeout: (s) {
-          _positionStream = null;
+          if (useForegroundNotification) {
+            _positionStreamFGN = null;
+          } else {
+            _positionStream = null;
+          }
           s.addError(TimeoutException(
             'Time limit reached while waiting for position update.',
             timeLimit,
@@ -190,7 +211,7 @@ class GeolocatorAndroid extends GeolocatorPlatform {
       );
     }
 
-    _positionStream = positionStream
+    final Stream<Position> tmpStream = positionStream
         .map<Position>((dynamic element) =>
             AndroidPosition.fromMap(element.cast<String, dynamic>()))
         .handleError(
@@ -201,13 +222,25 @@ class GeolocatorAndroid extends GeolocatorPlatform {
         throw error;
       },
     );
-    return _positionStream!;
+    if (useForegroundNotification) {
+      _positionStreamFGN = tmpStream;
+    } else {
+      _positionStream = tmpStream;
+    }
+    return tmpStream;
   }
 
-  Stream<dynamic> _wrapStream(Stream<dynamic> incoming) {
+  Stream<dynamic> _wrapStream(
+    Stream<dynamic> incoming,
+    bool useForegroundNotification,
+  ) {
     return incoming.asBroadcastStream(onCancel: (subscription) {
       subscription.cancel();
-      _positionStream = null;
+      if (useForegroundNotification) {
+        _positionStreamFGN = null;
+      } else {
+        _positionStream = null;
+      }
     });
   }