Determines when a scroll bar will be visible.
GTK_POLICY_ALWAYS
The scrollbar is always visible.
GTK_POLICY_AUTOMATIC
The scrollbar will appear and disappear as necessary. For example,
when all of a GtkCList can not be seen.
GTK_POLICY_NEVER
The scrollbar will never appear.
Determines when a scroll bar will be visible. GTK_POLICY_ALWAYS The scrollbar is always visible. GTK_POLICY_AUTOMATIC The scrollbar will appear and disappear as necessary. For example, when all of a GtkCList can not be seen. GTK_POLICY_NEVER The scrollbar will never appear.