edit-menu:undo

This method is called when the undo menu-item of the edit-menu menu is selected. If edit-menu:undo is bound to #f instead of a procedure, the undo menu item will not be created.

• (send a-frame:standard-menus edit-menu:undo item evt) -> void
      item : (instance (derived-from menu-item%))
      evt : (instance control-event%)

  Defaultly bound to:

    (lambda (menu evt) (let ((edit (get-edit-target-object))) (when (and edit (is-a? edit editor<%>)) (send edit do-edit-operation (quote undo)))) #t)