Only one item can be selected at any given moment. Other items
can have focus, but will not be marked as selected.
1
GTK_SELECTION_BROWSE
Only one item can be selected at any given moment. Any item
currently having focus will be marked as selected.
2
GTK_SELECTION_MULTIPLE
Several items may be selected or unselected with a click or using
the spacebar. They cannot be selected or unselected in any other
way. Note that multiple selection should only be used where all
items share the exact same callback routine.
3
GTK_SELECTION_EXTENDED
Several items may be selected or unselected using drag, or the shift
(selects all items from the leader to the current focus) or control
(selects the item having current focus) keys. Note that extended
selection should only be used where all items share the exact same
callback routine.