Gtkmm: Setting current tab label?

[fallenshadow]

I don't know why this seems so difficult but all I want to do is set the current tab label/title. Here is what I have so far:

        Gtk::Widget& widget = m_Notebook.get_current_page();
        Glib::ustring label = "TEST";
        m_Notebook.set_tab_label(widget, label);

The errors shown don't make much sense to me. :/

mainwindow.cc:545:59: error: invalid initialization of non-const reference of type ‘Gtk::Widget&’ from an rvalue of type ‘int’
mainwindow.cc:547:47: error: no matching function for call to ‘Gtk::Notebook::set_tab_label(Gtk::Widget&, Glib::ustring&)’
mainwindow.cc:547:47: note: candidate is:
/usr/include/gtkmm-3.0/gtkmm/notebook.h:435:8: note: void Gtk::Notebook::set_tab_label(Gtk::Widget&, Gtk::Widget&)
/usr/include/gtkmm-3.0/gtkmm/notebook.h:435:8: note: no known conversion for argument 2 from ‘Glib::ustring’ to ‘Gtk::Widget&’

Any help appreciated!

[r-senior]

The get_current_page() method returns the index number of the tab, not a widget:

https://developer.gnome.org/gtkmm/3....c551ede9015dff

To get the child widget, you need to pass the index number to get_nth_page(int page_num):

https://developer.gnome.org/gtkmm/3....40824c53f4c1ad

[fallenshadow]

This is what I have now:

        Gtk::Widget& widget = m_Notebook.get_nth_page(
                       m_Notebook.get_current_page());
        Glib::ustring label = "TEST";
        m_Notebook.set_tab_label(widget, label);

mainwindow.cc:546:53: error: invalid initialization of non-const reference of type ‘Gtk::Widget&’ from an rvalue of type ‘Gtk::Widget*’
mainwindow.cc:548:47: error: no matching function for call to ‘Gtk::Notebook::set_tab_label(Gtk::Widget&, Glib::ustring&)’
mainwindow.cc:548:47: note: candidate is:
/usr/include/gtkmm-3.0/gtkmm/notebook.h:435:8: note: void Gtk::Notebook::set_tab_label(Gtk::Widget&, Gtk::Widget&)
/usr/include/gtkmm-3.0/gtkmm/notebook.h:435:8: note: no known conversion for argument 2 from ‘Glib::ustring’ to ‘Gtk::Widget&’

Is this getting any closer?

[spjackson]

1. Dereference the pointer returned by get_nth_page.
2. Use set_tab_label_text.

        Gtk::Widget& widget = * m_Notebook.get_nth_page(
                       m_Notebook.get_current_page());
        Glib::ustring label = "TEST";
        m_Notebook.set_tab_label_text(widget, label);

[fallenshadow]

Thanks! (how do I mark this as solved? - not used to the new forum)

[fallenshadow]

Oh dear, it seems doing this will get rid of the close button for that tab. What would be the right solution for this?

Re-add a close button?

[r-senior]

I think the trick is that the tab label is a GtkWidget, as opposed to a GtkLabel. The gtk_notebook_set_tab_label_text() function is a convenience function that creates a GtkLabel and sets it as the widget for the tab's label. If you want to have a label and icon as the tab label, you need a container widget, e.g. a GtkBox that contains a GtkLabel and GtkImage/GtkButton. Then you use gtk_notebook_set_tab_label() instead of gtk_notebook_set_tab_label_text(). Expose the label as a property and connect up a signal to the image/button.

Sorry for quoting the C functions -- you know what I mean.

There's an example here, not in C++ but GTK is GTK:

http://stackoverflow.com/questions/2...ab-in-mono-gtk

[pbrane]

The actual tab widget has changed with your code. Remember you are using a custom function to create a notebook page tab with a close button. If you look at the add_page function in mainwindow.cc you'll see how the initial label is added.

Gtk::Label *label = Gtk::manage(new Gtk::Label(text));

you need to get a pointer/reference to that label widget to change the text. Something like this may work:

Gtk::Widget& widget = *m_Notebook.get_nth_page(m_Notebook.get_current_page());
Gtk::Widget label = widget.get_tab_label(widget);
label.set_text(Glib::ustring("TEST"));

I'm not sure if this is the correct code but it is the general idea.

[fallenshadow]

Thanks for the ideas! Yes pbrane this is what I really need to do, change the text of the label without disturbing the close button.

The widget class seems to have alot of functions: https://developer.gnome.org/gtkmm/3....1_1Widget.html

However, I can't see ones that would be of any use. As far as I understand widget is a class for general usage with any gtk widget, right? So it may not contain specific functions like what you mentioned.

mainwindow.cc:551:31: error: ‘class Gtk::Widget’ has no member named ‘get_tab_label’
mainwindow.cc:552:9: error: ‘class Gtk::Widget’ has no member named ‘set_text’

Im not so sure its possible to use widget functions to get what I need but you are definitely on the right track idea wise.

[fallenshadow]

Bump :S