[Oberon] Mice in Native Oberon.

[peter at easthope.ca]

In Native Oberon, 
====
MODULE Input;
	...
TYPE
	PollMouse* = PROCEDURE (VAR keys: SET; VAR dx, dy, dz: INTEGER): BOOLEAN;	(** non-portable *)
	...
	MousePoller = POINTER TO RECORD
		poll: PollMouse;
		next: MousePoller
	END;
		...
VAR
		...
	mouse: MousePoller;
====
Good!  mouse.next can point to a second mouse and etc.  That allows a list of mice.  

Further on,
====
PROCEDURE Mouse*(VAR keys: SET; VAR x, y: INTEGER);
	...
		REPEAT	(* get all available mouse events, or until keys change *)
			p := mouse; rawkeys := {}; ok := FALSE;
			WHILE p # NIL DO	(* poll all mice and sum keys and movements *)
				IF p.poll(mousekeys, dx, dy, dz) THEN 
					(* Assimilate mouse button information and X,Y coordinate information. *)
				END;
				p := p.next
			END
		UNTIL ~ok OR (rawkeys # lastkeys);
====

Observation
REPEAT .. UNTIL steps through the list of mice, assimilating 
information from each.  When more than one mouse is present, the 
input from each is equivalent to another.  Multiple mice simply allows 
redundancy.  In the sources, I've seen nothing to add a second mouse to 
the list.  

Conclusion
Input was built to allow multiple mice but the code to configure and use 
multiple mice wasn't developed.

Correct?  Erroneous?  Comments?

Thanks,                       ... Peter E.

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