feat: handle gestures in flutter

example/integration_test/controller_test.dart

@@ -25,7 +25,7 @@ void main() {
       await tester.pumpWidget(app);
       final ctrl = await ctrlCompleter.future;
       events.clear();
-      await ctrl.moveCamera(
+      ctrl.moveCamera(
         center: const Geographic(lon: 1, lat: 1),
         bearing: 1,
         zoom: 1,
@@ -742,7 +742,7 @@ void main() {
       final app = App(onMapCreated: ctrlCompleter.complete);
       await tester.pumpWidget(app);
       final ctrl = await ctrlCompleter.future;
-      await ctrl.moveCamera(
+      ctrl.moveCamera(
         center: const Geographic(lon: 1, lat: 2),
         bearing: 1,
         zoom: 1,

example/integration_test/map_scalebar_test.dart

@@ -33,7 +33,7 @@ void main() {
       final widths = <double>[];
 
       for (final zoom in zoomLevels) {
-        await ctrl.moveCamera(zoom: zoom);
+        ctrl.moveCamera(zoom: zoom);
         await tester.pumpAndSettle(const Duration(seconds: 2));
 
         final size = tester.getSize(customPaintFinder);

example/lib/controller_page.dart

@@ -31,7 +31,7 @@ class _ControllerPageState extends State<ControllerPage> {
                 OutlinedButton(
                   onPressed: () async {
                     debugPrint('moveCamera start');
-                    await _controller.moveCamera(
+                    _controller.moveCamera(
                       center: const Geographic(lon: 172.4714, lat: -42.4862),
                       zoom: 4,
                       pitch: 0,

maplibre/lib/src/map_camera.dart

@@ -56,4 +56,18 @@ class MapCamera {
 
   @override
   int get hashCode => Object.hash(center, zoom, bearing, pitch);
+
+  /// Returns a copy of this [MapCamera] with the given fields replaced by the
+  /// new values.
+  MapCamera copyWith({
+    Geographic? center,
+    double? zoom,
+    double? bearing,
+    double? pitch,
+  }) => MapCamera(
+    center: center ?? this.center,
+    zoom: zoom ?? this.zoom,
+    bearing: bearing ?? this.bearing,
+    pitch: pitch ?? this.pitch,
+  );
 }

maplibre/lib/src/map_controller.dart

@@ -42,7 +42,7 @@ abstract interface class MapController {
   List<Geographic> toLngLats(List<Offset> screenLocations);
 
   /// Instantly move the map camera to a new location.
-  Future<void> moveCamera({
+  void moveCamera({
     Geographic? center,
     double? zoom,
     double? bearing,