gboolean gtk_text_buffer_get_selection_bounds ( GtkTextBuffer* buffer, GtkTextIter* start, GtkTextIter* end )
TRUE if some text is selected; places the bounds
of the selection in
If the selection has length 0, then
end are filled
in with the same value.
end will be in ascending order.
NULL, then they are not filled in, but the
return value still indicates whether text is selected.