GtkComboBox with GtkTreeStore as model

[Diego Zuccato <diego otello alma unibo it>]

Hello all.

Is there any way to make a combobox handle a multi-column tree structure
(expand/collapse too, not only selection) ?
Up to now, I couldn't find any way to do it. If I use a collapsed tree,
the popup list isn't correctly mapped to the underlying model. If I use
more than one column, the one I see in the popup is not the same I see
in the box after selection.

Tks,
 Diego.