Stop sending map events once stream controller is closed

Author: JamesMcIntosh

packages/google_maps_flutter/google_maps_flutter_web/example/integration_test/google_maps_controller_test.dart

@@ -307,6 +307,44 @@ void main() {
         expect(events[4], isA<CameraIdleEvent>());
       });
 
+      testWidgets('stops listening to map events once disposed',
+          (WidgetTester tester) async {
+        controller = createController()
+          ..debugSetOverrides(
+            createMap: (_, __) => map,
+            circles: circles,
+            heatmaps: heatmaps,
+            markers: markers,
+            polygons: polygons,
+            polylines: polylines,
+            groundOverlays: groundOverlays,
+          )
+          ..init();
+
+        controller.dispose();
+
+        // Trigger events on the map, and verify they've been broadcast to the stream
+        final Stream<MapEvent<Object?>> capturedEvents = stream.stream.take(5);
+
+        gmaps.event.trigger(
+          map,
+          'click',
+          gmaps.MapMouseEvent()..latLng = gmaps.LatLng(0, 0),
+        );
+        gmaps.event.trigger(
+          map,
+          'rightclick',
+          gmaps.MapMouseEvent()..latLng = gmaps.LatLng(0, 0),
+        );
+        // The following line causes 2 events
+        gmaps.event.trigger(map, 'bounds_changed');
+        gmaps.event.trigger(map, 'idle');
+
+        final List<MapEvent<Object?>> events = await capturedEvents.toList();
+
+        expect(events, isEmpty);
+      });
+
       testWidgets("binds geometry controllers to map's",
           (WidgetTester tester) async {
         controller = createController()

packages/google_maps_flutter/google_maps_flutter_web/lib/src/google_maps_controller.dart

@@ -243,32 +243,44 @@ class GoogleMapController {
   void _attachMapEvents(gmaps.Map map) {
     map.onTilesloaded.first.then((void _) {
       // Report the map as ready to go the first time the tiles load
-      _streamController.add(WebMapReadyEvent(_mapId));
+      if (!_streamController.isClosed) {
+        _streamController.add(WebMapReadyEvent(_mapId));
+      }
     });
     map.onClick.listen((gmaps.MapMouseEventOrIconMouseEvent event) {
       assert(event.latLng != null);
-      _streamController.add(
-        MapTapEvent(_mapId, gmLatLngToLatLng(event.latLng!)),
-      );
+      if (!_streamController.isClosed) {
+        _streamController.add(
+          MapTapEvent(_mapId, gmLatLngToLatLng(event.latLng!)),
+        );
+      }
     });
     map.onRightclick.listen((gmaps.MapMouseEvent event) {
       assert(event.latLng != null);
-      _streamController.add(
-        MapLongPressEvent(_mapId, gmLatLngToLatLng(event.latLng!)),
-      );
+      if (!_streamController.isClosed) {
+        _streamController.add(
+          MapLongPressEvent(_mapId, gmLatLngToLatLng(event.latLng!)),
+        );
+      }
     });
     map.onBoundsChanged.listen((void _) {
       if (!_mapIsMoving) {
         _mapIsMoving = true;
-        _streamController.add(CameraMoveStartedEvent(_mapId));
+        if (!_streamController.isClosed) {
+          _streamController.add(CameraMoveStartedEvent(_mapId));
+        }
+      }
+      if (!_streamController.isClosed) {
+        _streamController.add(
+          CameraMoveEvent(_mapId, _gmViewportToCameraPosition(map)),
+        );
       }
-      _streamController.add(
-        CameraMoveEvent(_mapId, _gmViewportToCameraPosition(map)),
-      );
     });
     map.onIdle.listen((void _) {
       _mapIsMoving = false;
-      _streamController.add(CameraIdleEvent(_mapId));
+      if (!_streamController.isClosed) {
+        _streamController.add(CameraIdleEvent(_mapId));
+      }
     });
   }