Unfortunately that's beyond my capability, else I would have done it. I'd just like to know what was going in the mind of the person who decided to name an empty box "wxTreeCtrl". I just want to verify; the two are interchangeable in the current state am I right? What discrepancy exists between an empty white box and "wxTreeCtrl"?
The difference is that you probably have wxTreeCtrl styles and that you can write you initialization code after the wxSmith generated block of code.
Something like (look at the docks for wxTreeCtrl):
//(*
wxsmith block
//*)
tree->AddItem(...);
tree->AddItem(...);
As a hopefully final word, this is beyond inane. You can say I'm ignorant, but if the developers are competent enough to make a working dialog specifically for editing menu items, how hard is it to design a very similar one for wxTreeCtrl? Now I'm off to learn how to implement this GUI-specific attribute in code, which is totally counter-productive in relation to what could/should have been.
Read my explanation above.
About menus: most of the time the menuitems are just text + icon. So the editor for menus is useful in 99% of the cases.
For the tree the editor will be useful in only one case (static tree + text items only) and this case is very rare.