TreeView in Qt Quick Controls 2

Here are many KDE applications that use TreeView. They migrated to Qt Quick Controls 1, which has TreeView. But now we are migrating to Qt Quick Controls 2, which doesn't have TreeView. This is the main blocker for upgrading.

For desktop users, TreeView provides unique values. For a large list with folder structure, ListView isn't very useful. Changing to ListView also means a lot of modification to view model classes.