anchor.diff:    (column int)
     (gvalue gvalue))
   
  -(defgeneric tree-model-value (model row column))
  -
   (defmethod tree-model-value ((model tree-model) row column)
     (let ((index (tree-model-column-index model column)))
       (with-gvalue (gvalue)
         (%tree-model-get-value model (ensure-tree-iter model row) index gvalue))))
  -
  -(defgeneric tree-model-row-data (model row))
   
   (defmethod tree-model-row-data ((model tree-model) row)
     (coerce
  
positive.code: ;; TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  ;; SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  ;; $Id: gtktree.lisp,v 1.25 2006-10-17 15:27:52 espen Exp $
  
  
  (in-package "GTK")
  
negative.code: 
  ;;;; Cell Renderer
  
  (defmethod compute-signal-function ((gobject cell-renderer-toggle) (signal (eql 'toggled)) function object args)
    (declare (ignore gobject signal function object args))
    (let ((function (call-next-method)))
      #'(lambda (object path)
  	(funcall function object (ensure-tree-path path)))))
  