These use now more of a "pull" model, where they receive update
notifications and the relevant input position is queried, instead
of the coordinates being passed along.
This allows to treat cursor renderers all the same independently
of the device they track. This notifying of position changes should
ideally be more backend-y than core-y, a better location will be
figured out in future commits.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>
Without doing this, we'd use the same sprite that was last set by
mutter, most likely a leftptr cursor, and fail to update when e.g.
moving the pointer above a text entry and the displayed cursor updated
to a cursor position marker.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1391
On X11 we won't always receive cursor positions, as some other client
might have grabbed the pointer (e.g. for implementing a popup menu). To
make screen casting show a somewhat correct cursor position, we need to
actively poll the X server about the current cursor position.
We only really want to do this when screen casting or taking a
screenshot, so add an API that forces the cursor tracker to track the
cursor position.
On the native backend this is a no-op as we by default always track the
cursor position anyway.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1391
