GNOME's Mutter Now Supports XWayland Keyboard Grabbing, XDG-Output
The latest addition to the Mutter Wayland compositor is now handling XWayland keyboard grab support so an XWayland/X11 client can exclusively grab the keyboard input. And as part of that a new setting for controlling if XWayland clients can do keyboard grabs.
As can be seen from this lengthy bug report tracking GNOME's work on XWayland keyboard grabs and shortcut inhibitor support, this work has been big and a long time coming. XWayland keyboard grabs can be important for virtual machines and potentially some games too.
This is the GNOME-side for the XWayland keyboard grabbing support while already were the changes to the X Server / XWayland code. Since 2016 has also been the native Wayland protocol for keyboard grabs.
Separately, over the weekend Mutter also received XDG-Output support. The XDG-Output protocol is used for better describing desktop outputs/displays. This XDG-Output support should also be useful to XWayland clients.