Segfault on popup from a DrawingArea

[Christophe andral <christophe andral fr>]

Hi gtkmm team, all,

First question : Can I attach a popup menu on Gtk::DrawingArea widget ?
(If not, following questions are not relevant ^_^')

Second (and longer) question :
I implement a popup menu based on the gtkmm example:
http://library.gnome.org/devel/gtkmm-tutorial/unstable/sec-menus-examples.html.en#menu-example-popup

The differences are :
- my implem is on a DrawingArea child type and not a Gtk::Window child
- ActionGroup and UIManager are not attribute of my class but only
local variable to construction

Here is my piece of code:

    // Construct a popup menu
    Glib::RefPtr<Gtk::ActionGroup> m_refActionGroup =
Gtk::ActionGroup::create();
    //File|New sub menu:
    //These menu actions would normally already exist for a main menu, because a
    //context menu should not normally contain menu items that are
only available
    //via a context menu.
    m_refActionGroup->add(Gtk::Action::create("ContextMenu", "Context Menu"));

    m_refActionGroup->add(
        Gtk::Action::create("ContextEdit", "Edit"),
        sigc::mem_fun(*this, &PoutreSlotEditor::on_popup_generic));

    m_refActionGroup->add(
        Gtk::Action::create("ContextProcess", "Process"),
        // Gtk::AccelKey("<control>P"), // Since we don't call add_accel_group
        sigc::mem_fun(*this, &PoutreSlotEditor::on_popup_generic));

    m_refActionGroup->add(
        Gtk::Action::create("ContextRemove", "Remove"),
        sigc::mem_fun(*this, &PoutreSlotEditor::on_popup_generic));

    Glib::RefPtr<Gtk::UIManager> m_refUIManager = Gtk::UIManager::create();
    m_refUIManager->insert_action_group(m_refActionGroup);

    // It appears DrawingArea does not support add_accel_group
    // but Is it important for my case
    //add_accel_group(m_refUIManager->get_accel_group());

    //Layout the actions in a menubar and toolbar:
    Glib::ustring ui_info =
        "<ui>"
        "  <popup name='PopupMenu'>"
        "    <menuitem action='ContextEdit'/>"
        "    <menuitem action='ContextProcess'/>"
        "    <menuitem action='ContextRemove'/>"
        "  </popup>"
        "</ui>";
    #ifdef GLIBMM_EXCEPTIONS_ENABLED
    Log::DEBUG("GLIBMM_EXCEPTIONS_ENABLED");
    // It's the case for me
    try
    {
        m_refUIManager->add_ui_from_string(ui_info);
    }
    catch(const Glib::Error& ex)
    {
        Log::ERROR("building menus failed:%s", ex.what().c_str());
    }
    #else
    // Not my case
    Log::DEBUG("GLIBMM_EXCEPTIONS_ NOT _ENABLED");
    #endif

    //Get the menu:
    m_pMenuPopup =
dynamic_cast<Gtk::Menu*>(m_refUIManager->get_widget("/PopupMenu"));
    if(!m_pMenuPopup)
        Log::WARN("menu not found");

    // This function does not exist on DrawingArea
    // show_all_children();
    // May this call equivalent in my case ?
    m_pMenuPopup->show();

When I call the popup, I do the following (exactly what is said in the
example) :
if (event->button == 3 ) // Right button
        {
            if(m_pMenuPopup)
            {
                Log::DEBUG("Popup request");
                m_pMenuPopup->popup(event->button, event->time);
            }
        }

And I return true later in the code.

I valgrind execution and here is the stack trace :
==5008== Invalid read of size 4
==5008==    at 0x420A9E5: Gtk::Menu::popup(unsigned int, unsigned int)
(in /usr/lib/libgtkmm-2.4.so.1.1.0)
==5008==    by 0x805667F:
Poutre::PoutreSlotEditor::on_button_press_event(_GdkEventButton*)
(PoutreSlotEdito
r.cc:299)
==5008==    by 0x4294021:
Gtk::Widget_Class::button_press_event_callback(_GtkWidget*,
_GdkEventButton*) (in
/usr/lib/libgtkmm-2.4.so.1.1.0)
==5008==    by 0x45E0473: ??? (in /usr/lib/libgtk-x11-2.0.so.0.1800.3)
==5008==    by 0x4C036F8: ??? (in /usr/lib/libgobject-2.0.so.0.2200.3)
==5008==    by 0x4C05071: g_closure_invoke (in
/usr/lib/libgobject-2.0.so.0.2200.3)
==5008==    by 0x4C1A49D: ??? (in /usr/lib/libgobject-2.0.so.0.2200.3)
==5008==    by 0x4C1B9B7: g_signal_emit_valist (in
/usr/lib/libgobject-2.0.so.0.2200.3)
==5008==    by 0x4C1BFB5: g_signal_emit (in /usr/lib/libgobject-2.0.so.0.2200.3)
==5008==    by 0x46FC95D: ??? (in /usr/lib/libgtk-x11-2.0.so.0.1800.3)
==5008==    by 0x45D8C1F: gtk_propagate_event (in
/usr/lib/libgtk-x11-2.0.so.0.1800.3)
==5008==    by 0x45D9EA8: gtk_main_do_event (in
/usr/lib/libgtk-x11-2.0.so.0.1800.3)
==5008==  Address 0x76616b is not stack'd, malloc'd or (recently) free'd

What's wrong ? :(
Do I have to maintain instance of ActionGroup and UIManager in my class ?

Thank's in advance for your help,

Christophe