Returns a list of the items in the menu, popup menu, or menu bar. The
order of the items in the returned list corresponds to the order as
the user sees them in the menu or menu bar.
Called when the user clicks on the container as a menu bar (before the
user sees any menu items), just before the container as a popup menu
is popped up, or just before inspecting the menu bar containing the
item for a shortcut key binding.
If the container is not a menu bar or a popup menu, this method is
normally called via the on-demand
method of the container’s owning menu bar or popup menu, because the
default implementation of the method chains to the
on-demand method of its
items. However, the method can be overridden in a container such that
it does not call the on-demand method
of its items.
Calls the demand-callback
procedure that was provided when
the object was created, then calls the on-demand
method of the contained items.