[Interest] Qt/X11: obtaining a list of all owned

[René J.V. Bertin]

Hi,

I'm tinkering with the old KDE4 login manager for X11, KDM, porting it to Qt5/KF5. On startup, the greeter component kills all existing clients of the display using basic X11 calls in C. This was apparently never a problem, but it is under Qt5 where the greeter ends up killing itself.

Is there a way to obtain the list of all of an application's QWidgets and/or QWindows that are backed by an X11 Window instance (atom). Alternatively, is it possible to determine if QWindow::fromWinId() returns a QWindow that is owned by the running application?

Thanks,
R.