// Set up the onion skin toggle button
onion_skin = Gtk::manage(new class Gtk::ToggleButton());
onion_skin->set_active(work_area->get_onion_skin());
// Set up the onion skin toggle button
onion_skin = Gtk::manage(new class Gtk::ToggleButton());
onion_skin->set_active(work_area->get_onion_skin());