Each tool has its own MetaCursorRenderer instance, which is created/destroyed
upon proximity, and possibly updated through focus and set_cursor calls in
between.
This struct keeps the server side information for the wl_tablet_manager
global resource. It keeps the clients requesting this interface, and
does keep track of the plugged tablet devices, so
wl_tablet_manager.device_added is emitted on the expected clients.
Move into a standalone meta-wayland-surface-role-cursor.[ch], and
make generic enough to work for pointe and additional (eg. tablet)
cursors.
Most notably, the sprite is now kept completely internal to the
cursor role, and updates are routed through the given
MetaCursorRenderer (which may be the default one for the pointer,
or something else).
The way cursor updates after cursor surface destruction has also
been reworked, the pointer will just keep track of the last cursor
surface, so older surfaces being destroyed don't trigger pointer
rechecks/updates.
There's places where it would be convenient to add listeners to this,
so add the signal. The signal is only emitted once during destruction,
it is convenient for the places where we want notifications at a time
the object is still alive, as opposed to weak refs which notify after
the fact.
The device name is something more natural, similar to what's seen
in X11, the sysname is rather the event node basename, which may
also vary depending on device insertion/detection time.
Clutter out of tree depends on Cogl's required dependencies via the
pkg-config file. Since Clutter and Cogl moved in tree, it means that
those dependencies need to be checked by Clutter itself, otherwise
headers and libraries won't be found.
Leave these checks up to the callers, the only uses of this function
(indirect, through meta_wayland_seat_get_grab_info) are
[wl_shell|xdg]_surface.move/resize/show_window_menu.
In move/resize it makes sense to check for a button being pressed, because
we must expect a button release event. However for xdg_surface.show_window_menu
we 1) don't strictly need further events and 2) we must account for press+release
event pairs being processed at once in the compositor before the client sees
the former.
That is eg. the case of touchpad 2nd/3rd button tap emulation, multifinger
taps will emit the event pair at once, so when the client manages to request
xdg_surface.show_window_menu, it'll be too late in the compositor side, so the
request is ignored.
https://bugzilla.gnome.org/show_bug.cgi?id=764519
A wl_data_device object may be created while it is being focused,
either because the client destroyed it or because the client was
destroyed. Handle this by early out in focus handler vfuncs the case
where it was destroyed, so that we don't corrupt memory and/or cause
segmentation fault.
https://bugzilla.gnome.org/show_bug.cgi?id=765062
