fix(engine/linux): adjust GTK4 geometry sizing and compositor dimensions

engine/src/flutter/shell/platform/linux/fl_compositor_opengl.cc

@@ -375,8 +375,13 @@ static gboolean fl_compositor_opengl_render(FlCompositor* compositor,
 
   // If frame not ready, then wait for it.
   gint scale_factor = fl_gtk_surface_get_scale_factor(surface);
+#if FLUTTER_LINUX_GTK4
+  size_t width = fl_gtk_surface_get_width(surface);
+  size_t height = fl_gtk_surface_get_height(surface);
+#else
   size_t width = fl_gtk_surface_get_width(surface) * scale_factor;
   size_t height = fl_gtk_surface_get_height(surface) * scale_factor;
+#endif
   while (fl_framebuffer_get_width(self->framebuffer) != width ||
          fl_framebuffer_get_height(self->framebuffer) != height) {
     g_mutex_unlock(&self->frame_mutex);

engine/src/flutter/shell/platform/linux/fl_compositor_software.cc

@@ -83,8 +83,13 @@ static gboolean fl_compositor_software_render(FlCompositor* compositor,
 
   // If frame not ready, then wait for it.
   gint scale_factor = fl_gtk_surface_get_scale_factor(surface);
+#if FLUTTER_LINUX_GTK4
+  size_t width = fl_gtk_surface_get_width(surface);
+  size_t height = fl_gtk_surface_get_height(surface);
+#else
   size_t width = fl_gtk_surface_get_width(surface) * scale_factor;
   size_t height = fl_gtk_surface_get_height(surface) * scale_factor;
+#endif
   while (self->width != width || self->height != height) {
     g_mutex_unlock(&self->frame_mutex);
     fl_task_runner_wait(self->task_runner);

engine/src/flutter/shell/platform/linux/fl_view.cc

@@ -117,6 +117,14 @@ static void fl_renderable_iface_init(FlRenderableInterface* iface);
 static void fl_view_plugin_registry_iface_init(
     FlPluginRegistryInterface* iface);
 
+static void log_once(bool* flag, const char* message) {
+  if (*flag) {
+    return;
+  }
+  *flag = true;
+  g_warning("%s", message);
+}
+
 G_DEFINE_TYPE_WITH_CODE(
     FlView,
     fl_view,
@@ -167,8 +175,8 @@ static gboolean window_delete_event_cb(FlView* self) {
 static gboolean window_close_request_cb(GtkWindow* window, FlView* self) {
   (void)window;
   fl_engine_request_app_exit(self->engine);
-  // Stop the event from propagating.
-  return TRUE;
+  // Allow the default handler to destroy the window if the engine doesn't.
+  return FALSE;
 }
 #endif
 
@@ -251,11 +259,18 @@ static void setup_cursor(FlView* self) {
 }
 
 // Updates the engine with the current window metrics.
-static void handle_geometry_changed(FlView* self) {
-  GtkAllocation allocation;
-  gtk_widget_get_allocation(GTK_WIDGET(self), &allocation);
+static void handle_geometry_changed_with_size(FlView* self,
+                                              int width,
+                                              int height) {
   gint scale_factor = gtk_widget_get_scale_factor(GTK_WIDGET(self));
 
+  if (width == 0 || height == 0) {
+    static bool logged_zero_allocation = false;
+    log_once(&logged_zero_allocation,
+             "handle_geometry_changed: zero-size allocation");
+    return;
+  }
+
   // Note we can't detect if a window is moved between monitors - this
   // information is provided by Wayland but GTK only notifies us if the scale
   // has changed, so moving between two monitors of the same scale doesn't
@@ -276,9 +291,21 @@ static void handle_geometry_changed(FlView* self) {
     display_id = fl_display_monitor_get_display_id(
         fl_engine_get_display_monitor(self->engine), monitor);
   }
-  fl_engine_send_window_metrics_event(
-      self->engine, display_id, self->view_id, allocation.width * scale_factor,
-      allocation.height * scale_factor, scale_factor);
+  fl_engine_send_window_metrics_event(self->engine, display_id, self->view_id,
+                                      width * scale_factor,
+                                      height * scale_factor, scale_factor);
+}
+
+static void handle_geometry_changed(FlView* self) {
+#if FLUTTER_LINUX_GTK4
+  int width = gtk_widget_get_width(GTK_WIDGET(self->render_area));
+  int height = gtk_widget_get_height(GTK_WIDGET(self->render_area));
+  handle_geometry_changed_with_size(self, width, height);
+#else
+  GtkAllocation allocation;
+  gtk_widget_get_allocation(GTK_WIDGET(self), &allocation);
+  handle_geometry_changed_with_size(self, allocation.width, allocation.height);
+#endif
 }
 
 static void view_added_cb(GObject* object,
@@ -332,6 +359,12 @@ static void fl_view_present_layers(FlRenderable* renderable,
                                    size_t layers_count) {
   FlView* self = FL_VIEW(renderable);
 
+  if (layers_count > 0 && layers[0] != nullptr) {
+    static bool logged_first_layers = false;
+    log_once(&logged_first_layers,
+             "fl_view_present_layers: received first frame layers");
+  }
+
   fl_compositor_present_layers(self->compositor, layers, layers_count);
 
   // Perform the redraw in the GTK thead.
@@ -802,9 +835,7 @@ static void size_allocate_cb(FlView* self) {
 
 #if FLUTTER_LINUX_GTK4
 static void resize_cb(FlView* self, int width, int height) {
-  (void)width;
-  (void)height;
-  handle_geometry_changed(self);
+  handle_geometry_changed_with_size(self, width, height);
 }
 #endif
 
@@ -843,6 +874,12 @@ static gboolean draw_cb(FlView* self, cairo_t* cr) {
     gdk_gl_context_clear_current();
   }
 
+  if (!result) {
+    static bool logged_render_false = false;
+    log_once(&logged_render_false,
+             "draw_cb: compositor render returned false");
+  }
+
   return result;
 }
 

engine/src/flutter/shell/platform/linux/fl_window_monitor.cc

@@ -59,7 +59,7 @@ static void title_notify_cb(FlWindowMonitor* self) {
 static gboolean close_request_cb(FlWindowMonitor* self) {
   flutter::IsolateScope scope(self->isolate);
   self->on_close();
-  return TRUE;
+  return FALSE;
 }
 #else
 static gboolean delete_event_cb(FlWindowMonitor* self, GdkEvent* event) {