[gtkmm] Getting Reference to Menu Item from UIManager

[dwhitney67]

I'm evaluating gtkmm to see how it compares with OSF Motif in as far as developing a GUI is concerned. One thing that has me stumped is how to get a reference to a ToggleButton that has been created as a menu item in a UIManager.

Here's a snip of the code I am using:


...
m_refActionGroup = ActionGroup::create();
...
m_refActionGroup->add(Action::create("OptionsMenu", "Options"));
m_refActionGroup->add(ToggleAction::create("AlarmNotif", "Alarm Notification"), sigc::mem_fun(*this, &EventDisplay::alarmNotificationCB));
...
m_refUIManager = UIManager::create();
m_refUIManager->insert_action_group(m_refActionGroup);

add_accel_group(m_refUIManager->get_accel_group());

Glib::ustring ui_info = "<ui>"
" <menubar name='MenuBar'>"
...
" <menu action='OptionsMenu'>"
" <menuitem action='AlarmNotif'/>"
...
" </menubar>"
"</ui>";

try
{
m_refUIManager->add_ui_from_string(ui_info);

Widget* menubar = m_refUIManager->get_widget("/MenuBar"); // works!
Widget* togBut1 = m_refUIManager->get_widget("/AlarmNotif"); // fails!

...
}
catch (const Glib::Error& e)
{
std::cerr << "Building menus failed: " << e.what() << std::endl;
}

As shown above, I can successfully get the MenuBar, which is then packed into the VBox. However, when I attempt to get the AlarmNotif menu item, I get a NULL pointer result.

What is the proper way to get a reference to this object? During initialization of my Window, I want to set the ToggleButton using set_active().

Btw, I am currently referencing the following gtkmm documentation (http://library.gnome.org/devel/gtkmm-tutorial/stable/); is there anything else that is better and more comprehensive in scope?

[dwhitney67]

Well, I figured it out, after "endless" Googling. It's unfortunate the the Gnome Gtkmm documentation was written by lazy developers.

The proper way to reference an entry within a UIManager is to provide the full-path to the object within the hierarchy, not just the end-name as I was attempting to do.

So the correct way would be:


...
Widget* menubar = m_refUIManager->get_widget("/ui/MenuBar");
Widget* togBut = m_refUIManager->get_widget("/ui/MenuBar/OptionsMenu/AlarmNotif");


Of course, I realized that I would later require the reference to the toggle button, thus it was probably in my best interest to create a reference to it while setting up the menu, thus obviating the need to seek the reference as shown above. So in lieu of the above, this is what I did:


...
m_refActionGroup->add(Gtk::Action::create("OptionsMenu", "Options"));

m_alarmNotifToggle = Gtk::ToggleAction::create("AlarmNotif", "Alarm Notification", "", true);
m_refActionGroup->add(m_alarmNotifToggle, sigc::mem_fun(*this, &EventDisplay::alarmNotificationCB));

where m_alarmNotifToggle is declared in the header file as:


Glib::RefPtr<Gtk::ToggleAction> m_alarmNotifToggle;