It's a UI pattern that has been superseded by client-side decorations,
apps that used to set the hint have generally moved on to headerbars.
Given that and the limitation to server-side decorated X11 windows,
GTK4 removed the client-side API for setting the hint, it's time to
follow suite and retire the feature.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/221
Add a new client message "_XWAYLAND_MAY_GRAB_KEYBOARD" that X11 clients
can use to tell mutter this is a well behaving X11 client so it may
grant the keyboard grabs when requested.
An X11 client wishing to be granted Xwayland grabs by gnome-shell/mutter
must send a ClientMessage to the root window with:
- message_type set to "_XWAYLAND_MAY_GRAB_KEYBOARD"
- window set to the xid of the window on which the grab is to be issued
- data.l[0] to a non-zero value
Note: Sending this client message when running a plain native X11
environment would have no effect.
https://bugzilla.gnome.org/show_bug.cgi?id=783342
To keep feature parity with the Wayland backend, and
to improve the overall tiling experience with GTK apps,
add the _GTK_EDGE_CONSTRAINTS X11 atom and update it
when necessary.
https://bugzilla.gnome.org/show_bug.cgi?id=751857