gtk-drag-dest-target-list (widget)

widget -- a gtk-widget object that is a drag destination
tlist -- a gtk-target-list instance of droppable targets, or nil for none

The gtk-drag-dest-target-list function returns the list of targets this widget can accept from drag and drop. The (setf gtk-drag-dest-target-list) function sets the target types. The widget must first be made into a drag destination with the gtk-drag-dest-set function.