vbtkit/src/lego/PixmapVBT.i3

 Copyright (C) 1992, Digital Equipment Corporation                         
 All rights reserved.                                                      
 See the file COPYRIGHT for a full description.                            
                                                                           
 Last modified on Thu Sep 28 20:34:12 PDT 1995 by mhb        
      modified on Fri Jun 11 16:07:37 PDT 1993 by meehan     
      modified on Tue Jun 16 13:08:31 PDT 1992 by muller     

<*PRAGMA LL*>

 A PixmapVBT.T is a VBT that displays a pixmap.


   The minimum size of a PixmapVBT is just large enough to display
   its pixmap (surrounded by any margins that were supplied when the
   PixmapVBT was created). Its preferred size is the same as its
   minimum size, and its maximum size is very large. 


INTERFACE PixmapVBT;

IMPORT VBT, PaintOp, Pixmap;

TYPE
  T <: Public;
  Public =
    VBT.Leaf OBJECT
    METHODS
      <* LL.sup <= VBT.mu *>
      init (pm: Pixmap.T;
            halign, valign: REAL := 0.5;
            hmargin, vmargin: REAL := 0.0;
            op: PaintOp.T := PaintOp.BgFg;
            bg: PaintOp.T := PaintOp.Bg): T
    END;

 The call v.init(...) initializes v as a PixmapVBT displaying
   pixmap pm using the paint op op, and returns v.


   If halign = 0.0, the west boundary of the pixmap will be indented
   by the given hmargin (in millimeters) from the west boundary of
   the VBT; if halign = 1.0, the east boundary of the pixmap will
   be inside the east boundary of the VBT by the given hmargin;
   for other values of halign, the horizontal position of the text
   is computed by linear interpolation.  In particular, halign = 0.5
   centers the pixmap horizontally.  The vertical position is determined
   by vmargin and valign in a similar way.


   If the domain of v is larger than the pixmap, the background is
   painted using the tint bg.


   When the pixmap has depth 1, op should be a pair of tints.
   Otherwise, a good choice for op is PaintOp.Copy. 


PROCEDURE Put (v: T; pm: Pixmap.T);
<* LL.sup = VBT.mu *>

 Change the pixmap displayed by v to pm, and mark v for redisplay. 

PROCEDURE SetColors (v : T;
                     op: PaintOp.T;
                     bg: PaintOp.T   := PaintOp.Bg);
<* LL.sup = VBT.mu *>

 Change the op and bg of v, and mark v for redisplay. 

END PixmapVBT.