16.2.1.1 Example: dragging from a tree

This example returns string data for a tree-view defined below:

(defun tree-drag-callback (pane indices)

  (list :string 

        (string (elt (capi:collection-items pane)

                     (first indices)))))

(defun fruits (x) 

  (case x 

    (:fruits (list :apple :orange))

    (:apple (list :cox :bramley))

    (:orange (list :blood-orange :seville))

    (t nil)))

(capi:contain

 (make-instance 'capi:tree-view

                :title "Fruit tree"

                :roots '(:fruits)

                :children-function 'fruits

                :drag-callback 'tree-drag-callback))

There is a further example showing dragging from list-panel s in

CAPI User Guide (Macintosh version) - 30 Aug 2011