How to use multiple drag and drop in treeview?

[Liangxu Wang <wlx mygis org>]

Hi,
	DND can be supported by enable_mode_drag_source/dest function in
treeview widget, but if I want to use multiple DND in treeview, for
e.g., drag from another iconview, or drop to another widget, how to do
this? Should I implement all the targets in and out treeview myself?
	Thanks.

Sincerely yours,
Liangxu Wang