commander-s/scheme/std-viewer.scm

(define (make-standard-viewer value buffer)
  (let ((x 1)
	(y 1)
        (value value)
        (text (layout-result-standard 
               (exp->string value)
               (result-buffer-num-cols buffer))))
    (lambda (message)      
      (cond
       ((eq? message 'paint)
	(lambda (self win buffer have-focus?)
	  ;; #### get rid of this cruft
	  ((make-simple-result-buffer-printer y x text '() '())
	   win buffer have-focus?)))

       ((eq? message 'key-press)
	(lambda (self . ignore)
	  self))))))