public static void push_composite_child ()
Warning: push_composite_child is deprecated since 3.10.
Makes all newly-created widgets as composite children until the corresponding pop_composite_child call.
This API never really worked well and was mostly unused, now we have a more complete mechanism for composite children, see set_template.
A composite child is a child that’s an implementation detail of the container it’s inside and should not be visible to people using the container. Composite children aren’t treated differently by GTK+ (but see @foreach vs. forall), but e.g. GUI builders might want to treat them in a different way.