Prototype of the function called to create new child models when
gtk_tree_list_row_set_expanded() is called.
This function can return %NULL to indicate that item is guaranteed to be
a leaf node and will never have children. If it does not have children but
may get children later, it should return an empty model that is filled once
children arrive.
Prototype of the function called to create new child models when gtk_tree_list_row_set_expanded() is called.
This function can return %NULL to indicate that
itemis guaranteed to be a leaf node and will never have children. If it does not have children but may get children later, it should return an empty model that is filled once children arrive.