I may have misread the code back then but nice that you are taking care of it.

@Lorence
Yes its shows a tree structure

I've just seen the QDockWidget is closer to my needs. Anyway I still need to manully place something (i.e. a button) when the widget is closed to allow the users to reopen it.

It's quite simple, though. Just adding a toolbar and use the toggleViewAction() did the trick.