anchor.diff:      space))
   
   (defmethod allocate-space ((box hbox-pane) width height)
  +  (setf (sheet-region box) (make-bounding-rectangle 0 0 width height))
     (let ((h-percent (/ width (space-requirement-width (pane-space-requirement box))))
   	(v-percent (/ height (space-requirement-height (pane-space-requirement box))))
   	(x 0))
  
positive.code: 	for request = (pane-space-requirement child)
  	for new-width = (floor (* h-percent (space-requirement-width request)))
  	for new-height = (floor (* v-percent (space-requirement-height request)))
  	do (setf (sheet-region child)
  	     (make-bounding-rectangle 0 y new-width (+ y new-height)))
  	   (allocate-space child new-width new-height)
  	   (incf y new-height))))
  
  
  (defmacro changing-space-requirement (&body body &key resize-frame)
  
negative.code:           do (progn (loop for child in line-children
  			  for width in (first table-cell-sizes)
  			  for new-width = (floor (* v-percent width))
  			  do (progn (multiple-value-bind (x1 y1)
  					(bounding-rectangle* (sheet-region child))
  				      (setf (sheet-transformation child)
  					    (make-translation-transformation (- x x1) (- y y1))))
  				    (allocate-space child new-width new-height)
  				    (incf x new-width)))
  		    (setf x 0)
  