anchor.diff:  	   (allocate-space child new-width new-height)
   	   (incf y new-height))))
   
  -+
  +(defmacro changing-space-requirement (&key resize-frame &body body)
  +  (when body
  +    `(progn
  +       ,@body)))
  +;      (change-space-requirements ))))
  +
  +(defmethod change-space-requirements ((pane composite-pane)
  +				      &key resize-frame &rest space-req-keys
  +				      &key space-requirement-width
  +				      space-requirement-min-width
  +				      space-requirement-max-width
  +				      space-requirement-height
  +				      space-requirement-min-height
  +				      space-requirement-max-height)
  +  (declare (ignore space-req-keys))
  +  (when space-requirement-width
  +    (setf (space-requirement-width pane) space-requirement-width))
  +  (when space-requirement-min-width
  +    (setf (space-requirement-min-width pane) space-requirement-min-width))
  +  (when space-requirement-max-width
  +    (setf (space-requirement-max-width pane) space-requirement-max-width))
  +  (when space-requirement-height
  +    (setf (space-requirement-height pane) space-requirement-height))
  +  (when space-requirement-min-height
  +    (setf (space-requirement-min-height pane) space-requirement-min-height))
  +  (when space-requirement-max-height
  +    (setf (space-requirement-max-height pane) space-requirement-max-height))
  +  (if resize-frame
  +      (resize-frame (pane-frame pane))
  +      ; we didn't find the :resize-frame option in define-application-frame
  +    (note-space-requirements-changed (sheet-parent pane) pane)))
  +
  +(defmethod note-space-requirements-changed ((sheet composite-pane) (pane composite-pane))
  +  (if (eq sheet (sheet-parent pane))
  +      (compose-space pane)
  +      (compute-space sheet))
  +  (note-space-requirements-changed (sheet-parent sheet) pane))
  +
  +
  +;; SHEET 
  +
  +(defmethod note-space-requirements-changed ((sheet sheet) (pane composite-pane))
  +  (values))
  +
   
   ;;; HBOX-PANE class
   
  
positive.code: ;;; Boston, MA  02111-1307  USA.
  
  (in-package :CLIM-INTERNALS)
  
  (defclass space-requirement ()
    ((width :initform 0
  
negative.code:    (enabledp :initform nil
  	     :initarg :enabledp
  	     :accessor pane-enabledp)
     (space-requirement :initarg :space-requirement
  		      :initform (make-space-requirement :width 100 :max-width 100
  							:height 100 :max-height 100)
  		      :accessor pane-space-requirement)
     )
  