anim3D/src/BooleanPropProxy.i3

 Copyright (C) 1994, Digital Equipment Corporation                         
 Digital Internal Use Only                                                 
 All rights reserved.                                                      
                                                                           
 Last modified on Thu Jul 21 09:11:25 PDT 1994 by najork                   
       Created on Sat May 21 21:52:01 PDT 1994 by najork                   


 This interface reveals those aspects of the BooleanProp module that are
   related to proxied objects and to interfacing with an embedded language
   such as Obliq. It should be imported only by modules that implement
   this embedded language. 


INTERFACE BooleanPropProxy;

IMPORT Prop, ProxiedObj;

FROM BooleanProp IMPORT
  Name, Val, ConstBeh, SyncBeh, AsyncBeh, DepBeh, Request;

 Proxy Maker (PM) procedures for the various proxied object
   types are registered by assigning them to these variables. 


VAR
  NamePM     : PROCEDURE (x : Name)     := NIL;
  ValPM      : PROCEDURE (x : Val)      := NIL;
  ConstBehPM : PROCEDURE (x : ConstBeh) := NIL;
  SyncBehPM  : PROCEDURE (x : SyncBeh)  := NIL;
  AsyncBehPM : PROCEDURE (x : AsyncBeh) := NIL;
  DepBehPM   : PROCEDURE (x : DepBeh)   := NIL;
  RequestPM  : PROCEDURE (x : Request)  := NIL;

 The AsyncBeh and DepBeh types are abstract supertypes; concrete
   asynchronous and dependent behaviors are created by overriding the value
   method. We want to be able to do this not only from Modula-3, but also from
   the embedded language (e.g. Obliq). This is achieved by providing special
   proxy types.


   The proxy field of AsyncBeh and DepBeh must contain either NIL or
   an object of type AsyncBehProxy or DepBehProxy.



TYPE
  AsyncBehProxy = ProxiedObj.Proxy OBJECT
  METHODS
    compute (time : LONGREAL) : BOOLEAN RAISES {Prop.BadMethod};
  END;

  DepBehProxy = ProxiedObj.Proxy OBJECT
  METHODS
    compute (time : LONGREAL) : BOOLEAN RAISES {Prop.BadMethod};
  END;

  RequestProxy = ProxiedObj.Proxy OBJECT
  METHODS
    value (startval : BOOLEAN; reltime : REAL) : BOOLEAN
        RAISES {Prop.BadMethod};
  END;

END BooleanPropProxy.