gtk:tree-sortable-sort-column-id (sortable)

sortable -- a gtk:tree-sortable object
id -- an integer with the sort column ID
order -- a value of the gtk:sort-type enumeration

The gtk:tree-sortable-sort-column-id function returns the current sort column ID and the sort order. The (setf gtk:tree-sortable-sort-column-id) function sets the sort column ID and the sort order. If no sort order is given, the sort order is set to the default value :ascending.

The sortable will resort itself to reflect this change, after emitting a "sort-column-changed" signal. The id argument may either be a regular column ID, or one of the gtk:+default-sort-column-id+ or gtk:+unsorted-column-id+ special values.