Create FileOpen dialog on Qt

We develop application on Qt QML (QtQuick) that hasn't nice FileOpen dialog. So you need to create FileOpen dialog on Qt that will work like usual Windows FileOpen dialog and UI will not stop to respond during 5-6 seconds when open "My Computer". It should work for Windows/Mac and functionality core should be separated from UI (user interface). You don't need to skin UI, you need to focus on functionality. UI need only to test your functionality core and should have the same controls that Windows FileOpen dialog has. Later we'll port your functionality core to our QML UI. Functionality core should be inherited from QAbstractListModel then it will work with our QML UI. QAbstractListModel works with standart Qt UI too so you can build test UI using either QML or standart Qt UI. We use now temporary [login to view URL] solution that implemented QAbstractListModel and QDirModel behind but we want to replace it. The reason of this that Qt QDirModel/QFileSystemModel works bad with "MyComputer" when UI stops to respond during 5-6 seconds so it's bad way to use these classes. We found example [login to view URL] where coder uses boost and said that boost processes files in 2-3 times faster then QDirModel/QFileSystemModel. It can be a solution but we didn't test boost with "My Computer". In this example coder uses QAbstractItemModel inherited from QAbstractListModel so probably this should work with QML too. So you can take [login to view URL] and replace QDirModel to another engine, for example, boost if it will work correct. Or you can offer your solution.