FocusObject Class
The base class of the class that receives focus. It has basic functions related to focus, and all screen display classes that receive focus are derived from the FocusObject class.
The FocusObject class is a virtual class and cannot instantiate itself.
In the Mobile version, the FocusObject class does not exist because there is no concept of class, but in the explanation of common properties and methods, it is explained as FocusObject class for convenience.