System Classes

A System Class is a pre-defined class which is part of APLX. They are mostly used for user-interface programming. Examples are the Form, Timer, ChooseColor and Chart classes. (In previous versions of APLX, these classes were accessed through ⎕WI. Although you can continue to use ⎕WI, you may find the new class-based syntax more readable and more consistent.)

To create an instance of a top-level System class (such as a Form or a pre-defined dialog), you provide the name of the class as the right argument to ⎕NEW, and use '⎕' as the left argument to indicate that this is a System class:

      DLG←'⎕' ⎕NEW 'ChooseColor'
      DLG.⎕NL 3
Close
Create
Delete
New
Open
Send
Set
Show
Trigger

You can then use dot notation to access the properties and methods of the object:

      DLG.color←234 23 56
      DLG.Show
1

See the separate manual on System Classes and User-Interface Programming for more details.