How to create desktop manager window in X11?

[taaDeveloper]

I'm currently working on my own Linux distribution, writing a file manager that runs on Qt for the OS, and working on functionality for a desktop manager.
But I don't know how to set X11's _NET_WM_WINDOW_TYPE_DESKTOP type for a window in Qt.
What I've currently tried is
setWindowFlag(Qt::Desktop);
When you do this, the window will no longer be visible.
setAttribute(Qt::WA_X11NetWmWindowTypeDesktop);
When I did this, the window broke.
Is my method wrong?

[SGaist]

Hi and welcome to devnet,

You might want to check the LXQt project which seem to do what you want already. There might be information there to help you get going.