expose method for retrieving all child entities

lib/filament/entities/gizmo.dart

@@ -65,6 +65,9 @@ class Gizmo {
   }
 
   void detach() async {
+    await controller.setParent(x, 0);
+    await controller.setParent(y, 0);
+    await controller.setParent(z, 0);
     await controller.hide(x, null);
     await controller.hide(y, null);
     await controller.hide(z, null);

lib/filament/filament_controller.dart

@@ -576,6 +576,12 @@ abstract class FilamentController {
       double orbitSpeedY = 0.01,
       double zoomSpeed = 0.01});
 
+  ///
+  /// Returns all child entities under [parent].
+  ///
+  Future<List<FilamentEntity>> getChildEntities(
+      FilamentEntity parent, bool renderableOnly);
+
   ///
   /// Finds the child entity named [childName] associated with the given parent.
   /// Usually, [parent] will be the return value from [loadGlb]/[loadGltf] and [childName] will be the name of a node/mesh.
@@ -584,9 +590,9 @@ abstract class FilamentController {
       FilamentEntity parent, String childName);
 
   ///
-  /// List all child entities under the given entity.
+  /// List the name of all child entities under the given entity.
   ///
-  Future<List<String>> getChildEntities(FilamentEntity entity,
+  Future<List<String>> getChildEntityNames(FilamentEntity entity,
       {bool renderableOnly = true});
 
   ///

lib/filament/filament_controller_ffi.dart

@@ -358,7 +358,7 @@ class FilamentControllerFFI extends FilamentController {
     get_gizmo(_sceneManager!, out);
     var gizmo = Gizmo(out[0], out[1], out[2], this);
     allocator.free(out);
-    _scene = SceneImpl(gizmo);
+    _scene = SceneImpl(gizmo, this);
 
     hasViewer.value = true;
     _creating = false;
@@ -1504,8 +1504,19 @@ class FilamentControllerFFI extends FilamentController {
     return childEntity;
   }
 
+  Future<List<FilamentEntity>> getChildEntities(
+      FilamentEntity parent, bool renderableOnly) async {
+    var count = get_entity_count(_sceneManager!, parent, renderableOnly);
+    var out = allocator<Int32>(count);
+    get_entities(_sceneManager!, parent, renderableOnly, out);
+    var outList =
+        List.generate(count, (index) => out[index]).cast<FilamentEntity>();
+    allocator.free(out);
+    return outList;
+  }
+
   @override
-  Future<List<String>> getChildEntities(FilamentEntity entity,
+  Future<List<String>> getChildEntityNames(FilamentEntity entity,
       {bool renderableOnly = false}) async {
     var count = get_entity_count(_sceneManager!, entity, renderableOnly);
     var names = <String>[];

lib/filament/generated_bindings.dart

@@ -885,6 +885,17 @@ external int get_entity_count(
   bool renderableOnly,
 );
 
+@ffi.Native<
+        ffi.Void Function(
+            ffi.Pointer<ffi.Void>, EntityId, ffi.Bool, ffi.Pointer<EntityId>)>(
+    symbol: 'get_entities', assetId: 'flutter_filament_plugin')
+external void get_entities(
+  ffi.Pointer<ffi.Void> sceneManager,
+  int target,
+  bool renderableOnly,
+  ffi.Pointer<EntityId> out,
+);
+
 @ffi.Native<
         ffi.Pointer<ffi.Char> Function(
             ffi.Pointer<ffi.Void>, EntityId, ffi.Int, ffi.Bool)>(

lib/filament/scene.dart

@@ -9,7 +9,9 @@ class SceneImpl extends Scene {
   final Gizmo _gizmo;
   Gizmo get gizmo => _gizmo;
 
-  SceneImpl(this._gizmo);
+  FilamentController controller;
+
+  SceneImpl(this._gizmo, this.controller);
 
   @override
   FilamentEntity? selected;
@@ -35,8 +37,9 @@ class SceneImpl extends Scene {
     _onUpdatedController.add(true);
   }
 
-  void unregisterLight(FilamentEntity entity) {
-    if (selected == entity) {
+  void unregisterLight(FilamentEntity entity) async {
+    var children = await controller.getChildEntities(entity, true);
+    if (selected == entity || children.contains(selected)) {
       selected = null;
       _gizmo.detach();
     }
@@ -45,8 +48,9 @@ class SceneImpl extends Scene {
     _onUpdatedController.add(true);
   }
 
-  void unregisterEntity(FilamentEntity entity) {
-    if (selected == entity) {
+  void unregisterEntity(FilamentEntity entity) async {
+    var children = await controller.getChildEntities(entity, true);
+    if (selected == entity || children.contains(selected)) {
       selected = null;
       _gizmo.detach();
     }