Is there a Notifier in Smalltalk MT?

Each window implements its own window procedure (although most windows inherit the default window procedure in Window), and exports it to the operating system. A Smalltalk-created window other than a dialog box reserves private data in its window creation structure, and stores the address of the Smalltalk object in that slot (remember: in ST/MT, objects are never moved). A DialogBox functions exactly like a Dialog Box in C/C++ ; each instance has its own dialog procedure that references the Smalltalk object.