GtkComboBox style property appears-as-list

["Mohsen Saboorian" <mohsens gmail com>]

Hi,
1. Why the property "appears-as-list" of GtkComboBox is read only? A
user may want to have a scroll bar near a large list. I've noticed
that PyGTK has this property changeable:
http://www.pygtk.org/docs/pygtk/class-gtkcombobox.html

2. Is it possible to set the visible number of items
(GtkComboBoxEntry) in a combo box?

Thanks.