"NonDesktop" Proposed For RandR: Useful For VR & Apple Touch Bar Like Devices
The resource leasing has already been worked out as a candidate for the next update, RandR 1.6, while now this veteran X11 developer is proposing a new "NonDesktop" property for identifying outputs that are not conventional displays.
His primary use-case is for easily being able to report the virtual reality head mounted display (VR HMD) as a non-desktop device so window managers / compositors won't try to claim the device's video output and set it up as part of the desktop environment.
But he's also identified the Apple Touch Bar as another potential use-case. The Apple Touch Bar isn't yet properly supported on Linux but would be another output device that's best not be setup as a display output in a conventional Linux desktop setup.
Keith's RandR NonDesktop proposal can be read on xorg-devel and is relatively straight-forward so presumably should make it in without resistance for RandR 1.6.
Hopefully Keith's X-side changes for better Linux VR HMD support will be ready for X.Org Server 1.20 due out early next year. Meanwhile he also has the kernel-side DRM leasing bits queued for Linux 4.15.