insert_childmethoddelete_childmethodThese methods are called when a child is added to a manager widget, or when a child is destroyed. Their use is particularly important in those manager widgets which keep information about their children in private data structures.
Note that these are unchained methods, which means they are not automatically called for all the superclasses of a manager widget. XmRowColumn's insert_child() needs to call XmManager's insert_child(), which in turn calls the one in its superclass.