gtkmm glib gio critical

Question

On running the following simple.cc example for gtkmm

#include <gtkmm.h>

int main(int argc, char * argv[]){
  Glib::RefPtr<Gtk::Application> app
    = Gtk::Application::create(argc,argv,"org.gtkmm..examples.base");
  Gtk::Window window;
  //Gtk::ApplicationWindow window(app);                                         
  return app->run(window);                                                  
}

I face the following message:

 (process:9428): GLib-GIO-CRITICAL **: g_application_set_application_id: assertion `application_id == NULL || g_application_id_is_valid (application_id)' failed

However, the application doesn't break, the window is produced and doesn't exit until I ctr+C the program.

What are the implications of this GLib-GIO-Critical message ? What do I do to suppress the message ?

Answer 1

If the provided application-id is not valid then it will not be set. I'm not familiar with the glibmm bits, but if you don't provide an ID to g_application_new then, according to the documentation, "...some features of GApplication (most notably application uniqueness) will be disabled."

"Suppressing" it is easy--just fix it. Provide a valid application ID or don't provide one at all (pass NULL instead of a string). In your example, getting rid of the extra dot ("org.gtkmm.examples.base" instead of "org.gtkmm..examples.base") should do the trick. The g_application_id_is_valid documentation explains what constitutes a valid ID, including that "Application identifiers must not contain consecutive '.' (period) characters."