SuperCollider’s GUI redirect system returns the active kit’s class when you request a generic Window

SuperCollider uses a GUI redirect system: when you ask for a generic GUI class such as Window (or Slider, Button), SC returns an instance of the active GUI kit’s corresponding class (typically QWindow for the Qt kit). GUI.current returns the active kit. This portability layer means code written with generic class names runs unchanged on any supported kit. In practice you create a window with Window.new and must call .front to make it visible, since newly created windows are invisible; the underscore setter syntax (w.alwaysOnTop_(true)) chains attribute setters. Closing a window with .close or the X button permanently destroys the instance.

Examples

w = Window.new.front.alwaysOnTop_(true); w.close; GUI.current; // -> QtGUI

Assessment

Why should shared SuperCollider code use the generic Window class rather than QWindow directly? What does GUI.current tell you, and what does the redirect system do when you instantiate a generic Window?