cUIObject is an abstract class that provides the standard capabilities of a user interface object. All classes that have a user interface for display inherit all aspects of this class. Although this is a base class, its power and complexity are equal to those of any other class in the hierarchy.
This class does not actually exist as a stand-alone class, and therefore, cannot be used as a superclass or class of an object when defining new classes and objects. Instead, the base classes that provide a user interface for display (Edit, Menu, Message, and Scrollb) automatically incorporate all aspects of this class.
cUIObject is the most basic level at which accelerator keys are defined. The kCancel key has a null definition in this class, because its desired actions (undo + leave) are application-specific.