Add support for running flutter engine without UI

Signed-off-by: Rafal Walczyna <r.walczyna@samsung.com>

Author: rwalczyna

shell/platform/tizen/flutter_tizen.cc

@@ -35,6 +35,19 @@ FlutterWindowControllerRef FlutterCreateWindow(
   return state.release();
 }
 
+FlutterWindowControllerRef FlutterRunEngine(
+    const FlutterEngineProperties& engine_properties) {
+  StartLogging();
+  auto state = std::make_unique<FlutterWindowControllerState>();
+  state->engine = std::make_unique<TizenEmbedderEngine>(false);
+
+  if (!state->engine->RunEngine(engine_properties)) {
+    FT_LOGE("Failed to run the Flutter engine.");
+    return nullptr;
+  }
+  return state.release();
+}
+
 void FlutterDestroyWindow(FlutterWindowControllerRef controller) {
   if (controller->engine) {
     controller->engine->StopEngine();

shell/platform/tizen/public/flutter_tizen.h

@@ -40,6 +40,9 @@ typedef struct {
 FLUTTER_EXPORT FlutterWindowControllerRef
 FlutterCreateWindow(const FlutterEngineProperties& engine_properties);
 
+FLUTTER_EXPORT FlutterWindowControllerRef
+FlutterRunEngine(const FlutterEngineProperties& engine_properties);
+
 // Returns the plugin registrar handle for the plugin with the given name.
 //
 // The name must be unique across the application.

shell/platform/tizen/tizen_embedder_engine.cc

@@ -39,14 +39,8 @@ static DeviceProfile GetDeviceProfile() {
   return DeviceProfile::kUnknown;
 }
 
-TizenEmbedderEngine::TizenEmbedderEngine()
+TizenEmbedderEngine::TizenEmbedderEngine(bool initialize_tizen_renderer)
     : device_profile(GetDeviceProfile()) {
-#ifdef TIZEN_RENDERER_EVAS_GL
-  tizen_renderer = std::make_unique<TizenRendererEvasGL>(*this);
-#else
-  tizen_renderer = std::make_unique<TizenRendererEcoreWl2>(*this);
-#endif
-
   // Run flutter task on Tizen main loop.
   // Tizen engine has four threads (GPU thread, UI thread, IO thread, platform
   // thread). UI threads need to send flutter task to platform thread.
@@ -58,7 +52,20 @@ TizenEmbedderEngine::TizenEmbedderEngine()
         }
       });
 
+  messenger = std::make_unique<FlutterDesktopMessenger>();
+  messenger->engine = this;
+  message_dispatcher =
+      std::make_unique<flutter::IncomingMessageDispatcher>(messenger.get());
+
+  if (initialize_tizen_renderer) {
+    InitializeTizenRenderer();
+  }
+}
+
+void TizenEmbedderEngine::InitializeTizenRenderer() {
 #ifdef TIZEN_RENDERER_EVAS_GL
+  tizen_renderer = std::make_unique<TizenRendererEvasGL>(*this);
+
   render_loop_ = std::make_unique<TizenRenderEventLoop>(
       std::this_thread::get_id(),  // main thread
       [this](const auto* task) {
@@ -67,14 +74,8 @@ TizenEmbedderEngine::TizenEmbedderEngine()
         }
       },
       tizen_renderer.get());
-#endif
-
-  messenger = std::make_unique<FlutterDesktopMessenger>();
-  messenger->engine = this;
-  message_dispatcher =
-      std::make_unique<flutter::IncomingMessageDispatcher>(messenger.get());
-
-#ifndef TIZEN_RENDERER_EVAS_GL
+#else
+  tizen_renderer = std::make_unique<TizenRendererEcoreWl2>(*this);
   tizen_vsync_waiter_ = std::make_unique<TizenVsyncWaiter>(this);
 #endif
 }
@@ -111,7 +112,7 @@ UniqueAotDataPtr LoadAotData(std::string aot_data_path) {
 
 bool TizenEmbedderEngine::RunEngine(
     const FlutterEngineProperties& engine_properties) {
-  if (!tizen_renderer->IsValid()) {
+  if (HasTizenRenderer() && !tizen_renderer->IsValid()) {
     FT_LOGE("The display was not valid.");
     return false;
   }
@@ -138,40 +139,46 @@ bool TizenEmbedderEngine::RunEngine(
     static_cast<TizenEventLoop*>(data)->PostTask(task, target_time_nanos);
   };
   platform_task_runner.identifier = kPlatformTaskRunnerIdentifier;
-
-#ifdef TIZEN_RENDERER_EVAS_GL
-  FlutterTaskRunnerDescription render_task_runner = {};
-  render_task_runner.struct_size = sizeof(FlutterTaskRunnerDescription);
-  render_task_runner.user_data = render_loop_.get();
-  render_task_runner.runs_task_on_current_thread_callback =
-      [](void* data) -> bool {
-    return static_cast<TizenEventLoop*>(data)->RunsTasksOnCurrentThread();
-  };
-  render_task_runner.post_task_callback =
-      [](FlutterTask task, uint64_t target_time_nanos, void* data) -> void {
-    static_cast<TizenEventLoop*>(data)->PostTask(task, target_time_nanos);
-  };
-  render_task_runner.identifier = kRenderTaskRunnerIdentifier;
-#endif  
-
   FlutterCustomTaskRunners custom_task_runners = {};
   custom_task_runners.struct_size = sizeof(FlutterCustomTaskRunners);
   custom_task_runners.platform_task_runner = &platform_task_runner;
+
 #ifdef TIZEN_RENDERER_EVAS_GL
-  custom_task_runners.render_task_runner = &render_task_runner;
+  if (HasTizenRenderer()) {
+    FlutterTaskRunnerDescription render_task_runner = {};
+    render_task_runner.struct_size = sizeof(FlutterTaskRunnerDescription);
+    render_task_runner.user_data = render_loop_.get();
+    render_task_runner.runs_task_on_current_thread_callback =
+        [](void* data) -> bool {
+      return static_cast<TizenEventLoop*>(data)->RunsTasksOnCurrentThread();
+    };
+    render_task_runner.post_task_callback =
+        [](FlutterTask task, uint64_t target_time_nanos, void* data) -> void {
+      static_cast<TizenEventLoop*>(data)->PostTask(task, target_time_nanos);
+    };
+    render_task_runner.identifier = kRenderTaskRunnerIdentifier;
+    custom_task_runners.render_task_runner = &render_task_runner;
+  }
 #endif
 
   FlutterRendererConfig config = {};
-  config.type = kOpenGL;
-  config.open_gl.struct_size = sizeof(config.open_gl);
-  config.open_gl.make_current = MakeContextCurrent;
-  config.open_gl.make_resource_current = MakeResourceCurrent;
-  config.open_gl.clear_current = ClearContext;
-  config.open_gl.present = Present;
-  config.open_gl.fbo_callback = GetActiveFbo;
-  config.open_gl.surface_transformation = Transformation;
-  config.open_gl.gl_proc_resolver = GlProcResolver;
-  config.open_gl.gl_external_texture_frame_callback = OnAcquireExternalTexture;
+  if (HasTizenRenderer()) {
+    config.type = kOpenGL;
+    config.open_gl.struct_size = sizeof(config.open_gl);
+    config.open_gl.make_current = MakeContextCurrent;
+    config.open_gl.make_resource_current = MakeResourceCurrent;
+    config.open_gl.clear_current = ClearContext;
+    config.open_gl.present = Present;
+    config.open_gl.fbo_callback = GetActiveFbo;
+    config.open_gl.surface_transformation = Transformation;
+    config.open_gl.gl_proc_resolver = GlProcResolver;
+    config.open_gl.gl_external_texture_frame_callback =
+        OnAcquireExternalTexture;
+  } else {
+    config.type = kSoftware;
+    config.software.struct_size = sizeof(config.software);
+    config.software.surface_present_callback = SurfacePresentCallback;
+  }
 
   FlutterProjectArgs args = {};
   args.struct_size = sizeof(FlutterProjectArgs);
@@ -181,8 +188,11 @@ bool TizenEmbedderEngine::RunEngine(
   args.command_line_argv = &argv[0];
   args.platform_message_callback = OnFlutterPlatformMessage;
   args.custom_task_runners = &custom_task_runners;
+
 #ifndef TIZEN_RENDERER_EVAS_GL
-  args.vsync_callback = OnVsyncCallback;
+  if (HasTizenRenderer()) {
+    args.vsync_callback = OnVsyncCallback;
+  }
 #endif
 
   if (FlutterEngineRunsAOTCompiledDartCode()) {
@@ -203,36 +213,40 @@ bool TizenEmbedderEngine::RunEngine(
     return false;
   }
 
-  std::unique_ptr<FlutterTextureRegistrar> textures =
-      std::make_unique<FlutterTextureRegistrar>();
-  textures->flutter_engine = flutter_engine;
   plugin_registrar_ = std::make_unique<FlutterDesktopPluginRegistrar>();
   plugin_registrar_->engine = this;
-  plugin_registrar_->texture_registrar = std::move(textures);
 
   internal_plugin_registrar_ =
       std::make_unique<flutter::PluginRegistrar>(plugin_registrar_.get());
 
-  key_event_channel = std::make_unique<KeyEventChannel>(
-      internal_plugin_registrar_->messenger());
-  navigation_channel = std::make_unique<NavigationChannel>(
-      internal_plugin_registrar_->messenger());
   platform_channel = std::make_unique<PlatformChannel>(
       internal_plugin_registrar_->messenger());
   settings_channel = std::make_unique<SettingsChannel>(
       internal_plugin_registrar_->messenger());
-  text_input_channel = std::make_unique<TextInputChannel>(
-      internal_plugin_registrar_->messenger(), this);
   localization_channel = std::make_unique<LocalizationChannel>(flutter_engine);
   localization_channel->SendLocales();
   lifecycle_channel = std::make_unique<LifecycleChannel>(flutter_engine);
-  platform_view_channel = std::make_unique<PlatformViewChannel>(
-      internal_plugin_registrar_->messenger(), this);
 
-  key_event_handler_ = std::make_unique<KeyEventHandler>(this);
-  touch_event_handler_ = std::make_unique<TouchEventHandler>(this);
+  if (HasTizenRenderer()) {
+    std::unique_ptr<FlutterTextureRegistrar> textures =
+    std::make_unique<FlutterTextureRegistrar>();
+    textures->flutter_engine = flutter_engine;
+    plugin_registrar_->texture_registrar = std::move(textures);
+
+    key_event_channel = std::make_unique<KeyEventChannel>(
+        internal_plugin_registrar_->messenger());
+    navigation_channel = std::make_unique<NavigationChannel>(
+        internal_plugin_registrar_->messenger());
+    text_input_channel = std::make_unique<TextInputChannel>(
+        internal_plugin_registrar_->messenger(), this);
+    platform_view_channel = std::make_unique<PlatformViewChannel>(
+        internal_plugin_registrar_->messenger(), this);
+    key_event_handler_ = std::make_unique<KeyEventHandler>(this);
+    touch_event_handler_ = std::make_unique<TouchEventHandler>(this);
+
+    SetWindowOrientation(0);
+  }
 
-  SetWindowOrientation(0);
   return true;
 }
 
@@ -394,6 +408,14 @@ FlutterDesktopMessage TizenEmbedderEngine::ConvertToDesktopMessage(
   return message;
 }
 
+bool TizenEmbedderEngine::SurfacePresentCallback(void* user_data,
+                                                 const void* allocation,
+                                                 size_t row_bytes,
+                                                 size_t height) {
+  FT_LOGD("SurfacePresentCallback");
+  return true;
+}
+
 bool TizenEmbedderEngine::MakeContextCurrent(void* user_data) {
   return reinterpret_cast<TizenEmbedderEngine*>(user_data)
       ->tizen_renderer->OnMakeCurrent();
@@ -427,3 +449,7 @@ void* TizenEmbedderEngine::GlProcResolver(void* user_data, const char* name) {
   return reinterpret_cast<TizenEmbedderEngine*>(user_data)
       ->tizen_renderer->OnProcResolver(name);
 }
+
+bool TizenEmbedderEngine::HasTizenRenderer() {
+  return tizen_renderer != nullptr;
+}

shell/platform/tizen/tizen_embedder_engine.h

@@ -69,8 +69,9 @@ enum DeviceProfile { kUnknown, kMobile, kWearable, kTV, kCommon };
 // Manages state associated with the underlying FlutterEngine.
 class TizenEmbedderEngine : public TizenRenderer::Delegate {
  public:
-  explicit TizenEmbedderEngine();
+  explicit TizenEmbedderEngine(bool initialize_tizen_renderer = true);
   virtual ~TizenEmbedderEngine();
+  void InitializeTizenRenderer();
   bool RunEngine(const FlutterEngineProperties& engine_properties);
   bool StopEngine();
 
@@ -115,6 +116,7 @@ class TizenEmbedderEngine : public TizenRenderer::Delegate {
   const DeviceProfile device_profile;
 
  private:
+  static bool SurfacePresentCallback(void*, const void*, size_t, size_t);
   static bool MakeContextCurrent(void* user_data);
   static bool ClearContext(void* user_data);
   static bool Present(void* user_data);
@@ -134,6 +136,8 @@ class TizenEmbedderEngine : public TizenRenderer::Delegate {
                                        size_t width, size_t height,
                                        FlutterOpenGLTexture* texture);
 
+  bool HasTizenRenderer();
+
   // The handlers listening to platform events.
   std::unique_ptr<KeyEventHandler> key_event_handler_;
   std::unique_ptr<TouchEventHandler> touch_event_handler_;