Cherry-pick upstream#706 (Fixing memory leaks)

lib/src/controller.dart

@@ -149,7 +149,6 @@ class MaplibreMapController extends ChangeNotifier {
   }
 
   final OnStyleLoadedCallback? onStyleLoadedCallback;
-
   final OnMapClickCallback? onMapClick;
   final OnMapLongClickCallback? onMapLongClick;
 
@@ -967,4 +966,10 @@ class MaplibreMapController extends ChangeNotifier {
   Future<double> getMetersPerPixelAtLatitude(double latitude) async {
     return _mapboxGlPlatform.getMetersPerPixelAtLatitude(latitude);
   }
+
+  @override
+  void dispose() {
+    super.dispose();
+    _mapboxGlPlatform.dispose();
+  }
 }

lib/src/mapbox_map.dart

@@ -227,6 +227,15 @@ class _MaplibreMapState extends State<MaplibreMap> {
     _mapboxMapOptions = _MapboxMapOptions.fromWidget(widget);
   }
 
+  @override
+  void dispose() async {
+    super.dispose();
+    if (_controller.isCompleted) {
+      final controller = await _controller.future;
+      controller.dispose();
+    }
+  }
+
   @override
   void didUpdateWidget(MaplibreMap oldWidget) {
     super.didUpdateWidget(oldWidget);

maplibre_gl_platform_interface/lib/src/mapbox_gl_platform_interface.dart

@@ -311,4 +311,6 @@ abstract class MapLibreGlPlatform {
       {String? belowLayerId}) async {
     throw UnimplementedError('addFillLayer() has not been implemented.');
   }
+
+  void dispose() {}
 }

maplibre_gl_platform_interface/lib/src/method_channel_mapbox_gl.dart

@@ -794,4 +794,10 @@ class MethodChannelMaplibreGl extends MapLibreGlPlatform {
           .map((key, value) => MapEntry<String, String>(key, jsonEncode(value)))
     });
   }
+
+  @override
+  void dispose() {
+    super.dispose();
+    _channel.setMethodCallHandler(null);
+  }
 }