%!
% Date: 16 Sep 89 01:05:12 GMT
% From: dreams!rbogen@sun.com  (Richard Bogen)
% Subject: See how NeWS stacks up!
% To: news-makers@brillig.umd.edu
% 
%The following procedures display the contents of the operand stack or
%user dictionary for some interactive psh process. This file should
%be loaded into a psh and then the routines invoked with two parameters,
%the x & y location of the top left of a bounding rectangle for the
%display of the items. The contents of the display are updated every
%second. For example, 800 600 trackstack => process(..) object
%
% Author: Richard A. Bogen - Sun Microsystems, Inc. - 1989
%
/trackstack {% x y => process. Displays contents of parent's operand stack.
    {/OperandStack get} {100 string cvs} showobj} def

/trackdict {% x y => process. Display contents of parent's userdict.
    {/DictionaryStack get 1 get} 
    {exch 100 string cvs ( : ) append
     exch 100 string cvs append} 
    showobj} def

/showobj {% common routine for Operand Stack or Dictionary display
   10 dict begin
     /makestring exch def   %converts item to a sting
     /getobj exch def       %obtains object to be displayed
%First compute dimensions of items to be displayed
     /y0 exch def
     /x exch def
     /wd 30 def              %maximum number of chars permitted per item
     (M) stringbbox wd mul   %assumes (M) is the widest character 
     /wide exch def          % in the current font
     2 add /high exch def    %allow 2 units between each line
     pop pop
     /parent currentprocess def
%Now fork off a process to do the displaying
     {
      {parent /State get /zombie eq {currentcolor fillcanvas exit} if
       wide parent getobj length high mul dup neg y0 add /y exch def
       x y moveto rect 0 setgray %display in black
       parent getobj
         {makestring dup length wd gt
           {0 wd 1 sub getinterval} if
          dup stringwidth pop 
          neg wide add 2 div x add y moveto
          show /y y high add def } forall
      gsave stroke .0333 sleep grestore 
      RootColor setcolor fill
       } loop 
     } fork 
  end} def