Re: Using a TreeStore with a ComboBox

["Jonathon Jongsma" <jonathon jongsma gmail com>]

On 6/22/07, Jef Driesen <jefdriesen hotmail com> wrote:
> Jonathon Jongsma wrote:
> > On 6/21/07, Jef Driesen <jefdriesen hotmail com> wrote:
> >> Using a treestore model with a combobox creates a nice dropdown list
> >> with submenus. Inside each submenu, the parent item is shown with a
> >> separator below to separate it from its children. I want to know how I
> >> can hide this parent node, so I can only select leaf nodes (e.g items
> >> without children).
> >>
> >> The model contains places that can be are arranged by the user in an
> >> arbitrary hierarchy, to group related places together (for instance by
> >> continent and/or country). This is very similar how files (my places)
> >> can be arranged into directories (my hierarchy). But when the user needs
> >> to select a place with the combobox, it doesn't make sense to be able to
> >> select an item that is not a place.
> >
> > You could probably accomplish this fairly easily with TreeModelFilter
> > (http://gtkmm.org/docs/gtkmm-2.4/docs/reference/html/classGtk_1_1TreeModelFilter.html)
> > wrapping your existing treestore. You'd just need to provide a
> > function which checks whether a node has children or not, and pass
> > that function to TreeModelFilter::set_visible_func().  Hope that
> > helps.
>
> I tried a TreeModelFilter like this:
>
> Glib::RefPtr<Gtk::TreeStore> store = Gtk::TreeStore::create(m_columns);
> Glib::RefPtr<Gtk::TreeModelFilter> filter = Gtk::TreeModelFilter::create
> (store);
> filter->set_visible_func (sigc::mem_fun(*this, &Example::on_model_visible
> combo.set_model(filter);
>
> bool
> Example::on_model_visible (const Gtk:TreeModel::const_iterator& iter)
> {
>     return iter->children().empty();
> }
>
> But it doesn't work. Exactly the same tree structure is shown if the
> model is populated after the set_visible_func. Or the combobox is
> completely empty, if the tree is populated before that.

does it work if you explicitly call TreeModelFilter::refilter() after
populating the model?  I'm not sure whether this should be necessary,
but it might give you a clue as to what's not working...

--
jonner