ui/src/split/RigidVBT.i3

 Copyright (C) 1992, Digital Equipment Corporation                         
 All rights reserved.                                                      
 See the file COPYRIGHT for a full description.                            
                                                                           
 Last modified on Mon Feb 24 14:01:21 PST 1992 by muller                   

<*PRAGMA LL*>

 A RigidVBT.T is a filter whose size range is set explicitly,
   independently of its child's size range.  In spite of its name,
   it size range does not have to be fixed to a single value.


   All dimensions in this interface are specified in millimeters. 


INTERFACE RigidVBT;

IMPORT VBT, Filter, Axis;

TYPE
  T <: Public;
  Public = Filter.T OBJECT METHODS
    <* LL.sup <= VBT.mu *>
    init(ch: VBT.T; sh: Shape): T
  END;

TYPE
  SizeRange = RECORD lo, pref, hi: REAL END;
  Shape = ARRAY Axis.T OF SizeRange;

 The call v.init(...) initializes v as a rigid VBT with
   child ch and shape sh.


   A RigidVBT.SizeRange is like a VBT.SizeRange, but in millimeters
   instead of pixels, using REALs instead of INTEGERs, and the
   range is [lo..hi] instead of [lo..hi-1]. 




PROCEDURE New(ch: VBT.T; sh: Shape): T;

 New(...) is equivalent to NEW(T).init(...). 

PROCEDURE FromHV(
  ch: VBT.T;
  hMin, vMin: REAL;
  hMax, vMax, hPref, vPref: REAL := -1.0) : T;
  <* LL.sup <= VBT.mu *>

 Return a RigidVBT with child ch and the given shape. 
 If hMax or hPref are defaulted, they are assumed to be the
   same as hMin, and similarly for vMax, vPref and vMin.
   That is, FromHV is equivalent to:



      IF hMax = -1.0 THEN hMax := hMin END;
      IF vMax = -1.0 THEN vMax := vMin END;
      IF hPref = -1.0 THEN hPref := hMin END;
      IF vPref = -1.0 THEN vPref := vMin END;
      RETURN New(ch,
        Shape{SizeRange{h, hMax, hPref},
              SizeRange{v, vMax, vPref}})





END RigidVBT.