GtkCOmboBox, handling pre-selection

[Yury Alyaev <mutab0r rambler ru>]

Hello all,

I'm trying to manage the following task: when a GtkComboBox is activated 
(its pop-down list is shown), moving the pointer above it causes 
selection changing, but no signal is emitted. The signal @changed@ is 
emitted when any list item is selecting by click, but I also want to 
handle selection changing when pointer moving. It it possible without 
hard Gtk+ hack? Currently I use 2.22, if it does matter.