update native linux entry point

Author: julian-CStack

scripts/app_config/templates/linux/my_application.cc

@@ -14,6 +14,12 @@ struct _MyApplication {
 
 G_DEFINE_TYPE(MyApplication, my_application, GTK_TYPE_APPLICATION)
 
+// Called when first Flutter frame received.
+static void first_frame_cb(MyApplication* self, FlView *view)
+{
+    gtk_widget_show(gtk_widget_get_toplevel(GTK_WIDGET(view)));
+}
+
 // Implements GApplication::activate.
 static void my_application_activate(GApplication* application) {
   MyApplication* self = MY_APPLICATION(application);
@@ -54,9 +60,18 @@ static void my_application_activate(GApplication* application) {
   fl_dart_project_set_dart_entrypoint_arguments(project, self->dart_entrypoint_arguments);
 
   FlView* view = fl_view_new(project);
+  GdkRGBA background_color;
+  // Background defaults to black, override it here if necessary, e.g. #00000000 for transparent.
+  gdk_rgba_parse(&background_color, "#000000");
+  fl_view_set_background_color(view, &background_color);
   gtk_widget_show(GTK_WIDGET(view));
   gtk_container_add(GTK_CONTAINER(window), GTK_WIDGET(view));
 
+  // Show the window when Flutter renders.
+  // Requires the view to be realized so we can start rendering.
+  g_signal_connect_swapped(view, "first-frame", G_CALLBACK(first_frame_cb), self);
+  gtk_widget_realize(GTK_WIDGET(view));
+
   fl_register_plugins(FL_PLUGIN_REGISTRY(view));
 
   gtk_widget_grab_focus(GTK_WIDGET(view));
@@ -81,6 +96,24 @@ static gboolean my_application_local_command_line(GApplication* application, gch
   return TRUE;
 }
 
+// Implements GApplication::startup.
+static void my_application_startup(GApplication* application) {
+  //MyApplication* self = MY_APPLICATION(object);
+
+  // Perform any actions required at application startup.
+
+  G_APPLICATION_CLASS(my_application_parent_class)->startup(application);
+}
+
+// Implements GApplication::shutdown.
+static void my_application_shutdown(GApplication* application) {
+  //MyApplication* self = MY_APPLICATION(object);
+
+  // Perform any actions required at application shutdown.
+
+  G_APPLICATION_CLASS(my_application_parent_class)->shutdown(application);
+}
+
 // Implements GObject::dispose.
 static void my_application_dispose(GObject* object) {
   MyApplication* self = MY_APPLICATION(object);
@@ -91,12 +124,20 @@ static void my_application_dispose(GObject* object) {
 static void my_application_class_init(MyApplicationClass* klass) {
   G_APPLICATION_CLASS(klass)->activate = my_application_activate;
   G_APPLICATION_CLASS(klass)->local_command_line = my_application_local_command_line;
+  G_APPLICATION_CLASS(klass)->startup = my_application_startup;
+  G_APPLICATION_CLASS(klass)->shutdown = my_application_shutdown;
   G_OBJECT_CLASS(klass)->dispose = my_application_dispose;
 }
 
 static void my_application_init(MyApplication* self) {}
 
 MyApplication* my_application_new() {
+  // Set the program name to the application ID, which helps various systems
+  // like GTK and desktop environments map this running application to its
+  // corresponding .desktop file. This ensures better integration by allowing
+  // the application to be recognized beyond its binary name.
+  g_set_prgname(APPLICATION_ID);
+
   return MY_APPLICATION(g_object_new(my_application_get_type(),
                                      "application-id", APPLICATION_ID,
                                      "flags", G_APPLICATION_NON_UNIQUE,