Low-level APIs for objects that can lay their children out.
Used for containers like Efl.Ui.Box and Efl.Ui.Table.
Requests EFL to recalculate the layout of this object.
void efl_pack_layout_request(Eo *obj);
Implementation of this container's layout algorithm.
void efl_pack_layout_update(Eo *obj);
Sent after the layout was updated.