vbtkit/src/etext/KeyTrans.i3

 Copyright (C) 1992, Digital Equipment Corporation                         
 All rights reserved.                                                      
 See the file COPYRIGHT for a full description.                            
                                                                           
 Last modified on Tue Jun 16 13:08:45 PDT 1992 by muller     
      modified on Sat Jun 13 12:32:56 PDT 1992 by meehan     
      modified on Tue Feb  4 16:42:03 PST 1992 by mhb        
      modified on Wed Nov 14 16:18:34 PST 1990 by brooks     




INTERFACE KeyTrans;

 KeyTrans is a utility interface that provides some standard
   mapping between keyboard keys and ASCII characters. 


IMPORT VBT;

CONST
  NullKey = '\000';

PROCEDURE Latin1 (key: VBT.KeySym): CHAR;

 Return the ISO-Latin-1 character corresponding to key.


   \medskip\bulletitem If 32 <= key <= 255, then return
   VAL(key, CHAR).


   \medskip\bulletitem If key is Key.Backspace, Key.Tab,
   Key.Return, Key.Escape, or Key.Delete, then return the
   corresponding character.


   \medskip\bulletitem Otherwise return NullKey 

PROCEDURE TTY (READONLY cd: VBT.KeyRec): CHAR;

 Similar to Latin1, but if this is a control key, then clear
   the ``high-order bits'' from the character code.  For example,
   for both control-a and control-A, we return VAL(1, CHAR). 

END KeyTrans.