Add Linux platform support for fetching refresh rate on startup. (#52934

) This patch addresses the missing implementation of `platformDispatcher.views` on Linux. It checks the refresh rate of the renderer's window and returns the value. Without this implementation, `WidgetsBinding.instance.platformDispatcher.views.first.display.size` would throw an exception on Linux, preventing safe usage. Related: flutter/flutter#144230
flutter · May 28, 2024 · 416c619 · 416c619
1 parent cf201b1
commit 416c619
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Showing 9 changed files with 116 additions and 3 deletions.
diff --git a/shell/platform/linux/fl_engine.cc b/shell/platform/linux/fl_engine.cc
@@ -573,6 573,26 @@ gboolean fl_engine_start(FlEngine* self, GError** error) {
  g_warning("Failed to enable accessibility features on Flutter engine");
  }
 
  gdouble refresh_rate = fl_renderer_get_refresh_rate(self->renderer);
  // FlutterEngineDisplay::refresh_rate expects 0 if the refresh rate is
  // unknown.
  if (refresh_rate <= 0.0) {
  refresh_rate = 0.0;
  }
  FlutterEngineDisplay display = {};
  display.struct_size = sizeof(FlutterEngineDisplay);
  display.display_id = 0;
  display.single_display = true;
  display.refresh_rate = refresh_rate;
 
  std::vector displays = {display};
  result = self->embedder_api.NotifyDisplayUpdate(
  self->engine, kFlutterEngineDisplaysUpdateTypeStartup, displays.data(),
  displays.size());
  if (result != kSuccess) {
  g_warning("Failed to notify display update to Flutter engine: %d", result);
  }
 
  return TRUE;
 }
 

diff --git a/shell/platform/linux/fl_renderer.cc b/shell/platform/linux/fl_renderer.cc
@@ -153,6 153,11 @@ void fl_renderer_clear_current(FlRenderer* self) {
  FL_RENDERER_GET_CLASS(self)->clear_current(self);
 }
 
 gdouble fl_renderer_get_refresh_rate(FlRenderer* self) {
  g_return_val_if_fail(FL_IS_RENDERER(self), -1.0);
  return FL_RENDERER_GET_CLASS(self)->get_refresh_rate(self);
 }
 
 guint32 fl_renderer_get_fbo(FlRenderer* self) {
  g_return_val_if_fail(FL_IS_RENDERER(self), 0);
 

diff --git a/shell/platform/linux/fl_renderer.h b/shell/platform/linux/fl_renderer.h
@@ -80,6 80,16 @@ struct _FlRendererClass {
  */
  gboolean (*collect_backing_store)(FlRenderer* renderer,
  const FlutterBackingStore* backing_store);
 
  /**
  * Virtual method called when Flutter wants to get the refresh rate of the
  * renderer.
  * @renderer: an #FlRenderer.
  *
  * Returns: The refresh rate of the display in Hz. If the refresh rate is
  * not available, returns -1.0.
  */
  gdouble (*get_refresh_rate)(FlRenderer* renderer);
 };
 
 /**
@@ -223,6 233,15 @@ void fl_renderer_render(FlRenderer* renderer, int width, int height);
  */
 void fl_renderer_cleanup(FlRenderer* renderer);
 
 /**
  * fl_renderer_get_refresh_rate:
  * @renderer: an #FlRenderer.
  *
  * Returns: The refresh rate of the display in Hz. If the refresh rate is
  * not available, returns -1.0.
  */
 gdouble fl_renderer_get_refresh_rate(FlRenderer* renderer);
 
 G_END_DECLS
 
 #endif // FLUTTER_SHELL_PLATFORM_LINUX_FL_RENDERER_H_
diff --git a/shell/platform/linux/fl_renderer_gdk.cc b/shell/platform/linux/fl_renderer_gdk.cc
@@ -36,6 36,23 @@ static void fl_renderer_gdk_clear_current(FlRenderer* renderer) {
  gdk_gl_context_clear_current();
 }
 
 static gdouble fl_renderer_gdk_get_refresh_rate(FlRenderer* renderer) {
  FlRendererGdk* self = FL_RENDERER_GDK(renderer);
  GdkDisplay* display = gdk_window_get_display(self->window);
  GdkMonitor* monitor =
  gdk_display_get_monitor_at_window(display, self->window);
  if (monitor == nullptr) {
  return -1.0;
  }
 
  int refresh_rate = gdk_monitor_get_refresh_rate(monitor);
  if (refresh_rate <= 0) {
  return -1.0;
  }
  // the return value is in milli-hertz, convert to hertz
  return static_cast<gdouble>(refresh_rate) / 1000.0;
 }
 
 static void fl_renderer_gdk_dispose(GObject* object) {
  FlRendererGdk* self = FL_RENDERER_GDK(object);
 
@@ -52,6 69,7 @@ static void fl_renderer_gdk_class_init(FlRendererGdkClass* klass) {
  FL_RENDERER_CLASS(klass)->make_resource_current =
  fl_renderer_gdk_make_resource_current;
  FL_RENDERER_CLASS(klass)->clear_current = fl_renderer_gdk_clear_current;
  FL_RENDERER_CLASS(klass)->get_refresh_rate = fl_renderer_gdk_get_refresh_rate;
 }
 
 static void fl_renderer_gdk_init(FlRendererGdk* self) {}

diff --git a/shell/platform/linux/fl_renderer_headless.cc b/shell/platform/linux/fl_renderer_headless.cc
@@ -19,11 19,18 @@ static void fl_renderer_headless_make_resource_current(FlRenderer* renderer) {}
 // Implements FlRenderer::clear_current.
 static void fl_renderer_headless_clear_current(FlRenderer* renderer) {}
 
 // Implements FlRenderer::get_refresh_rate.
 static gdouble fl_renderer_headless_get_refresh_rate(FlRenderer* renderer) {
  return -1.0;
 }
 
 static void fl_renderer_headless_class_init(FlRendererHeadlessClass* klass) {
  FL_RENDERER_CLASS(klass)->make_current = fl_renderer_headless_make_current;
  FL_RENDERER_CLASS(klass)->make_resource_current =
  fl_renderer_headless_make_resource_current;
  FL_RENDERER_CLASS(klass)->clear_current = fl_renderer_headless_clear_current;
  FL_RENDERER_CLASS(klass)->get_refresh_rate =
  fl_renderer_headless_get_refresh_rate;
 }
 
 static void fl_renderer_headless_init(FlRendererHeadless* self) {}

diff --git a/shell/platform/linux/fl_renderer_test.cc b/shell/platform/linux/fl_renderer_test.cc
@@ -51,3 51,19 @@ TEST(FlRendererTest, RestoresGLState) {
 
  g_object_ref_sink(view);
 }
 
 static constexpr double kExpectedRefreshRate = 120.0;
 static gdouble renderer_get_refresh_rate(FlRenderer* renderer) {
  return kExpectedRefreshRate;
 }
 
 TEST(FlRendererTest, RefreshRate) {
  flutter::testing::fl_ensure_gtk_init();
  g_autoptr(FlDartProject) project = fl_dart_project_new();
  g_autoptr(FlMockRenderer) renderer =
  fl_mock_renderer_new(&renderer_get_refresh_rate);
 
  gdouble result_refresh_rate =
  fl_renderer_get_refresh_rate(FL_RENDERER(renderer));
  EXPECT_DOUBLE_EQ(result_refresh_rate, kExpectedRefreshRate);
 }
diff --git a/shell/platform/linux/testing/mock_engine.cc b/shell/platform/linux/testing/mock_engine.cc
@@ -513,6 513,14 @@ FlutterEngineResult FlutterEngineUnregisterExternalTexture(
  return kSuccess;
 }
 
 FlutterEngineResult FlutterEngineNotifyDisplayUpdate(
  FLUTTER_API_SYMBOL(FlutterEngine) engine,
  FlutterEngineDisplaysUpdateType update_type,
  const FlutterEngineDisplay* displays,
  size_t display_count) {
  return kSuccess;
 }
 
 } // namespace
 
 FlutterEngineResult FlutterEngineGetProcAddresses(
@@ -552,5 560,6 @@ FlutterEngineResult FlutterEngineGetProcAddresses(
  table->UnregisterExternalTexture = &FlutterEngineUnregisterExternalTexture;
  table->UpdateAccessibilityFeatures =
  &FlutterEngineUpdateAccessibilityFeatures;
  table->NotifyDisplayUpdate = &FlutterEngineNotifyDisplayUpdate;
  return kSuccess;
 }
diff --git a/shell/platform/linux/testing/mock_renderer.cc b/shell/platform/linux/testing/mock_renderer.cc
@@ -6,6 6,7 @@
 
 struct _FlMockRenderer {
  FlRenderer parent_instance;
  FlMockRendererGetRefreshRate get_refresh_rate;
 };
 
 G_DEFINE_TYPE(FlMockRenderer, fl_mock_renderer, fl_renderer_get_type())
@@ -19,16 20,31 @@ static void fl_mock_renderer_make_resource_current(FlRenderer* renderer) {}
 // Implements FlRenderer::clear_current.
 static void fl_mock_renderer_clear_current(FlRenderer* renderer) {}
 
 // Implements FlRenderer::get_refresh_rate.
 static gdouble fl_mock_renderer_default_get_refresh_rate(FlRenderer* renderer) {
  FlMockRenderer* self = FL_MOCK_RENDERER(renderer);
  if (self->get_refresh_rate != nullptr) {
  return self->get_refresh_rate(renderer);
  }
  return -1.0;
 }
 
 static void fl_mock_renderer_class_init(FlMockRendererClass* klass) {
  FL_RENDERER_CLASS(klass)->make_current = fl_mock_renderer_make_current;
  FL_RENDERER_CLASS(klass)->make_resource_current =
  fl_mock_renderer_make_resource_current;
  FL_RENDERER_CLASS(klass)->clear_current = fl_mock_renderer_clear_current;
  FL_RENDERER_CLASS(klass)->get_refresh_rate =
  fl_mock_renderer_default_get_refresh_rate;
 }
 
 static void fl_mock_renderer_init(FlMockRenderer* self) {}
 
 // Creates a stub renderer
-FlMockRenderer* fl_mock_renderer_new() {
- return FL_MOCK_RENDERER(g_object_new(fl_mock_renderer_get_type(), nullptr));
 FlMockRenderer* fl_mock_renderer_new(
  FlMockRendererGetRefreshRate get_refresh_rate) {
  FlMockRenderer* fl_mock_renderer = FL_MOCK_RENDERER(
  g_object_new_valist(fl_mock_renderer_get_type(), nullptr, nullptr));
  fl_mock_renderer->get_refresh_rate = get_refresh_rate;
  return fl_mock_renderer;
 }
diff --git a/shell/platform/linux/testing/mock_renderer.h b/shell/platform/linux/testing/mock_renderer.h
@@ -15,7 15,10 @@ G_DECLARE_FINAL_TYPE(FlMockRenderer,
  MOCK_RENDERER,
  FlRenderer)
 
-FlMockRenderer* fl_mock_renderer_new();
 typedef gdouble (*FlMockRendererGetRefreshRate)(FlRenderer* renderer);
 
 FlMockRenderer* fl_mock_renderer_new(
  FlMockRendererGetRefreshRate get_refresh_rate = nullptr);
 
 G_END_DECLS