[TreeView] Drag and drop : cancel a drop

[Thymus <thymus gmail com>]

Hello evreybody,

first, sorry for my english, I'm belgian -_-.

I have a TreeView with two differents "type" of row.
This type is a column, there is submenu and other.

A row wich a type submenu has child.

I would like control where a row will be dropped.

If it's a submenu, all right.
But, if it isn't, I will cancel the drop to show a dialog says "You couldn't add a child to a row that is not a submenu."

Could you help me ?

Thanks a lot :]

Raphaël