We've long used a switch statement on the grab operation to determine
where events should go. The issue with MetaGrabOp is that it's a mixture
of a few different things, including event routing, state management,
and the behavior to choose during operations.
This leads to poorly defined event routing and hard-to-follow logic,
since it's sometimes unclear what should point where, and our utility
methods for determining grab operations apart can be poorly named.
To fix this, establish the concept of a "event route", which describes
where events should be routed to.
Instead of returning a value based on whether or not we handled it, we
have this logic: either we have taken a grab on the window, in which
case we have a grab op and have handled it ourselves, or we did not take
a grab and *need* to replay the event to the window.
Handle this in events.c by checking the grab operation in the same way
that we check the other grab ops.
MetaGestureTracker has been separating the "did I handle an event?" and the
"should the event be filtered out?" questions, merge this and make
handle_event() reply to "should the event be only handled by me?".
If a sequence wasn't accepted yet by the gesture tracker, the event will
go through (eg. not handled exclusively by the gesture tracker) and it'll
still be processed by Clutter, triggering gesture actions, and maybe
changing the sequence into other state.
https://bugzilla.gnome.org/show_bug.cgi?id=733631
This function tells the obvious on X11, and implements a similar mechanism
on wayland to determine the "pointer emulating" sequence, or one to stick
with when implementing single-touch behavior.
https://bugzilla.gnome.org/show_bug.cgi?id=733631
It isn't necessary. As an X11 compositor, we'll only see the event
if we have the grab on the window, anyway.
This was causing issues moving windows as a Wayland compositor.
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.
This doesn't particularly matter, since we fall through into a default
case that does nothing right below, but this matches the other paths
and it prevents us from falling into a trap if we add other event types
below.
If we start a grab op from a keybind / menu, we'll handle the
ButtonPress and drop the grab then, never giving the window a chance
to handle what it needs to do before the grab is dropped.
This means that if you use Alt+F7 to move a window around, move it
to a side-tiling or maximization area, and then left-click, it will
just hang there in the sky.
The reason we don't simply use gdk_window_add_filter directly is
because of some twisted idea that any GDK symbol being used from
core/ is a layer violation. While we certainly want to keep any
serious GDK code out of ui/, event handling is quite important
to have in core/, so simply use a GDK event filter directly.
We previously separated out MetaDisplay and MetaScreen. mutter
would only manage one screen, but we still kept a list of screens
for simplicity.
With Wayland support, we no longer care about the ability to
manage more than one screen at a time. Remove this by killing
the list of screens, in favor of having just one MetaScreen
in MetaDisplay.
We also kill off active_screen at the same time, since it's
not necessary anymore.
A future cleanup should merge MetaDisplay and MetaScreen. To avoid
breaking API, we should probably keep MetaScreen around as a dummy
type.
display.c is getting a bit crowded. Move most of the handling
out to another file, events.c.
The long-term goal is to have generic event handling here, with
backend-specific handling for the types of windows and such.
