From 15882891e245df410077dd177458ef2cb2f58608 Mon Sep 17 00:00:00 2001
From: Nick Fisher <nick.fisher@avinium.com>
Date: Sat, 20 Apr 2024 13:46:10 +0800
Subject: [PATCH] use void callback for setBackgroundImage to correctly free
 pointer after dispatch

---
 ios/include/FlutterFilamentFFIApi.h       | 2 +-
 ios/src/FlutterFilamentFFIApi.cpp         | 7 +++++--
 lib/filament/filament_controller_ffi.dart | 4 +++-
 lib/filament/generated_bindings.dart      | 5 +++--
 4 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/ios/include/FlutterFilamentFFIApi.h b/ios/include/FlutterFilamentFFIApi.h
index e4f50675..b79083ee 100644
--- a/ios/include/FlutterFilamentFFIApi.h
+++ b/ios/include/FlutterFilamentFFIApi.h
@@ -36,7 +36,7 @@ extern "C"
     FLUTTER_PLUGIN_EXPORT void update_viewport_and_camera_projection_ffi(void *const viewer, const uint32_t width, const uint32_t height, const float scaleFactor, void (*onComplete)());
     FLUTTER_PLUGIN_EXPORT void set_background_color_ffi(void *const viewer, const float r, const float g, const float b, const float a);
     FLUTTER_PLUGIN_EXPORT void clear_background_image_ffi(void *const viewer);
-    FLUTTER_PLUGIN_EXPORT void set_background_image_ffi(void *const viewer, const char *path, bool fillHeight);
+    FLUTTER_PLUGIN_EXPORT void set_background_image_ffi(void *const viewer, const char *path, bool fillHeight, void (*onComplete)());
     FLUTTER_PLUGIN_EXPORT void set_background_image_position_ffi(void *const viewer, float x, float y, bool clamp);
     FLUTTER_PLUGIN_EXPORT void set_tone_mapping_ffi(void *const viewer, int toneMapping);
     FLUTTER_PLUGIN_EXPORT void set_bloom_ffi(void *const viewer, float strength);
diff --git a/ios/src/FlutterFilamentFFIApi.cpp b/ios/src/FlutterFilamentFFIApi.cpp
index a3b93a01..779a10fa 100644
--- a/ios/src/FlutterFilamentFFIApi.cpp
+++ b/ios/src/FlutterFilamentFFIApi.cpp
@@ -307,9 +307,12 @@ FLUTTER_PLUGIN_EXPORT void clear_background_image_ffi(void *const viewer) {
 
 FLUTTER_PLUGIN_EXPORT void set_background_image_ffi(void *const viewer,
                                                     const char *path,
-                                                    bool fillHeight) {
+                                                    bool fillHeight, void (*callback)()) {
   std::packaged_task<void()> lambda(
-      [=] { set_background_image(viewer, path, fillHeight); });
+      [=] { 
+        set_background_image(viewer, path, fillHeight); 
+        callback();
+      });
   auto fut = _rl->add_task(lambda);
 }
 FLUTTER_PLUGIN_EXPORT void set_background_image_position_ffi(void *const viewer,
diff --git a/lib/filament/filament_controller_ffi.dart b/lib/filament/filament_controller_ffi.dart
index 2e9f946b..c6513929 100644
--- a/lib/filament/filament_controller_ffi.dart
+++ b/lib/filament/filament_controller_ffi.dart
@@ -531,8 +531,10 @@ class FilamentControllerFFI extends FilamentController {
       throw Exception("No viewer available, ignoring");
     }
     final pathPtr = path.toNativeUtf8().cast<Char>();
+    await _withVoidCallback((cb) {
+      set_background_image_ffi(_viewer!, pathPtr, fillHeight, cb);
+    });
 
-    set_background_image_ffi(_viewer!, pathPtr, fillHeight);
     allocator.free(pathPtr);
   }
 
diff --git a/lib/filament/generated_bindings.dart b/lib/filament/generated_bindings.dart
index 306478a9..5e91552f 100644
--- a/lib/filament/generated_bindings.dart
+++ b/lib/filament/generated_bindings.dart
@@ -1147,13 +1147,14 @@ external void clear_background_image_ffi(
 );
 
 @ffi.Native<
-        ffi.Void Function(
-            ffi.Pointer<ffi.Void>, ffi.Pointer<ffi.Char>, ffi.Bool)>(
+        ffi.Void Function(ffi.Pointer<ffi.Void>, ffi.Pointer<ffi.Char>,
+            ffi.Bool, ffi.Pointer<ffi.NativeFunction<ffi.Void Function()>>)>(
     symbol: 'set_background_image_ffi', assetId: 'flutter_filament_plugin')
 external void set_background_image_ffi(
   ffi.Pointer<ffi.Void> viewer,
   ffi.Pointer<ffi.Char> path,
   bool fillHeight,
+  ffi.Pointer<ffi.NativeFunction<ffi.Void Function()>> onComplete,
 );
 
 @ffi.Native<