Now that we don't have to regrab to change the cursor, since it's
simply the cursor on the root window, all we have to do is update
the cursor on the screen.
We expect that meta_screen_set_cursor while grabbed will properly
set the cursor on the root window. Make sure this works by simply
always using the root cursor when we have an active grab.
When we're a Wayland compositor, we get all the events, no exceptions,
so we don't need to grab.
This was masking focusing and raising issues under nested that showed
up under native.
Since commit 6e8d1d79d, move operations are always performed for
the (toplevel) parent of all transient, which is just plain silly
if the dialog is not actually attached to its parent (either because
the dialog is not modal or the setting is disabled).
Grab operations are now always taken on the backend connection, and
this breaks GTK+'s event handling.
Instead of taking a grab op, just do the handling ourselves. The
GTK+ connection will get an implicit grab, which means pointer /
keyboard events won't be sent to the rest of mutter, which is good.
Now that we grab devices on the X11 connection, we can run into
cross-connection issues. Since GTK+ frames are on the UI connection,
they'll get the passive grab when we click on them. Forcibly ungrab
on GTK+'s connection before attempting to take a grab on the backend
connection ourselves.
It's been long enough. We can mandate support for these, at least
at build-time. The code doesn't actually compile without either
of these, so just consider that unsupported.
Looking at the code paths where is_mouse / is_keyboard are used,
all of them should never be run when dealing with a COMPOSITOR
grab op, since they're filtered out above or the method is just
never run during that time.
It's confusing that COMPOSITOR is in here, and requires us to
be funny with other places in code, so just take it out.
The idea here is that while we take a WM-side grab, like a compositor
grab or a resizing grab, we need to remove the focus from the Wayland
client.
We make a special exception for CLICKING operations, because these
are really an internal state machine while you're pressing on a button
inside a frame, and in this case, we need to not kill the focus.
A careful analysis of mutter's codebase shows that nothing actually
passes anything but 0 to this. gnome-shell has one instance, but it's
most likely a mistake.
Remove the grab_mask field and the one place in keybindings.c that uses it.
The parameter to begin_grab_op is left in for API compatibility reasons.
