Custom QDirModel

[wysota]

Any link regarding example of wrapping QDirModel with a proxy model?

No, sorry - you are the first one to do it.

About a single item. It's customer's requirement so I can't just throw away it.

But you can convince your customer. Often people think and say they want something even if they don't need it.

By the way, the custom item is supposed to be able to expand and show My Documents folder contents. So a title is not a solution

If it's a single item then when it is not expanded the view is useless and can be disabled or left empty. It's one of obvious GUI design rules. Besides, a view with a single item looks silly...

Ok, I found QSortFilterProxyModel. But I cannot see how it can help me.

It can't. You are looking for QAbstractProxyModel. You need to subclass it and implement mapToSource(), mapFromSource() and reimplement QAbstractItemModel::data(). But I still think the requirement is silly and you should avoid implementing it. Instead just enable or disable the view when needed.