The only case we have is the case where the two X11 connections are the
same. When on Wayland, the XSync is costly and expensive, and we should
minimize it.
Commit 8100cefd4c fixed a crash during workspace initialization by
tweaking the startup sequence; as a result, the plugin (like gnome-shell)
is now started before workspaces are fully initialized, which breaks
some reasonable assumptions (like always having an active workspace).
This is particularly problematic considering that the code making those
assumptions is not necessarily our own (extensions!), so return to
fully initialize workspaces before the compositor again.
At the same time, make sure to only call meta_workspace_activate()
once during initialization to avoid reintroducing the crash.
https://bugzilla.gnome.org/show_bug.cgi?id=732695
This makes sure that we see them for Wayland clients as well, and don't
time out and crash when we're accessing an invalid window / surface.
Spotted-by: Rui Matos <tiagomatos@gmail.com>
If a sequence moves past a certain distance without being used by a
gesture, reject it so clients may see and react to it ASAP. This makes
gestures to be began by initially quasi-static touchpoints, in addition to
quasi-simultaneous.
Touch events will be caught first by the compositor this way,
whenever the MetaGestureTracker notifies of the accepted/rejected
state of a sequence, XIAllowTouchEvents() will be called on it
accordingly, so it is handled exclusively by the compositor or
punted to clients.
This object tracks both touch sequences happening on the stage and
gestures attached to the stage actor. When a gesture emits
::gesture-begin, All triggering sequences and future ones will be
marked as "accepted" by the compositor, and events will be listened
for meanwhile there are active gestures.
If a sequence goes unclaimed for a short time, it will be
automatically "denied", and punted to the client or shell element
below.
Touch events are largely ignored on GdkEvent emulation, so only
make frames receive pointer events, only the pointer emulating
touch will be reported, and any other further touches will be
ignored, which is about the behavior we want. This makes window
dragging possible again on touch.
Since Wayland configures are more of a hint to the client than anything,
we don't want to save the unconstrained rect when we're just hinting to
the client that it should resize, since it could ignore us. This would
get us stuck in a loop, since meta_window_move_resize_now would use the
unconstrained_rect to resize, and we don't remove the resize from the
queue if we have an outstanding request like that.
This fixes a bunch of traffic / CPU usage when trying to resize
weston-terminal.
For XWayland, we need to make sure to send out mouse events on O-R
windows, otherwise they won't get motion or button events.
The comment mentions being eaten for the compositor, but we already
bypass the compositor for all events that have a window. The return
value just controls whether we pass them to Wayland.
The output_id is more of an opaque identifier for the monitor, based on
its underlying ID from the windowing system. Since we also use the term
"output_id" for the output's index, rename our use of the opaque cookie
"output_id" to "winsys_id".
The GDK and hence GNOME standard is that keys that begin with XF86 according to
libxkbcommon not prefixed with XF86, though gdk_keyval_from_name() strips XF86
if provided. If libxkbcommon doesn't recognize the accelerator name without
XF86, try again adding XF86 to the start.
This restores compatibility with gnome-settings-daemon, schemas, and existing
user configuration.
https://bugzilla.gnome.org/show_bug.cgi?id=727993
It just gets in the way of gnome-shell's log handler (which
includes gjs backtraces optionally), it requires people to understand
what 8 or 16 mean as log levels, and it loses the log domain.
Some plugins and extensions want to be able to know when the sticky
field of a window changes, so add a property for it and allow them
to connect to the notify::on-all-workspaces signal.
When workspaces-only-on-primary is set and a window is moved back to the
primary, we also move it to the active workspace to avoid the confusion
of a visible window suddenly disappearing when crossing the monitor border.
However when the window is not actually moved by the user, preserving the
workspace makes more sense - we already do this in some cases (e.g. when
moving between primary monitors), but miss others (unplugging the previous
monitor); just add an explicit user_op parameter as used elsewhere to cover
all exceptions.
https://bugzilla.gnome.org/show_bug.cgi?id=731760
Remember the last monitor a window was moved to by user action and
try to move it back on monitor changes; this should match user
expectations much better when a monitor is unplugged temporarily.
https://bugzilla.gnome.org/show_bug.cgi?id=731760
When workspaces-only-on-primary is set, a window can be on all
workspaces either because it is on a non-primary workspace, or
because it was explicitly made sticky. Only the latter is reflected
in _NET_WM_STATE, but both will result in a "magic" _NET_WM_DESKTOP,
which we (and probably other WMs) use to set the initial sticky state.
So to avoid confusing other WMs (or ourselves), make sure to only
have _NET_WM_STATE_STICKY reflected in _NET_WM_DESKTOP when unmanaging.
Window state like maximization and minimization should be preserved
over restarts - in a patch review, this would qualify as "needs-work",
so revert the cleanup until the issues are fixed.
This reverts commit dc6decefb5.
Rather than calculate it speculatively with the current properties
which may be too new or too out of date, make sure it always fits
with the proper definition. We update it when we update the toplevel
window for X11, and when a Wayland surface is committed with a newly
attached buffer.
With get_input_region existing, get_input_rect is a misnomer. Really,
it's about the geometry of the output surface, and it's only used that
way in the compositor code.
Way back when in GNOME 3.2, get_input_rect was added when we added
invisible borders. get_outer_rect was always synonymous with server-side
geometry of the toplevel. get_outer_rect was used for both user-side
policy (the "frame rect") and to get the geometry of the window.
Invisible borders were meant to extend the input region of the frame
window silently. Since most users of get_outer_rect cared about the
frame rect, we kept that the same and added a new method, get_input_rect
to get the full rect of the framed window with all invisible borders for
input kept on.
As time went on and CSD and Wayland became a reality, the relationship
between the server-side geometry and the "frame rect" became more
complicated, as can be evidenced by the recent commits. Since clients
don't tend to be framed anymore, they set their own input region.
get_buffer_rect is also sort of a poor name, since X11 doesn't really
have buffers, but we don't really have many other alternatives.
This doesn't change any of the code, nor the meaning. It will always
refer to the rectangle where the toplevel should be placed.
All of the users of get_input_rect don't actually want a synthesized
input rect based off of the current margins. What they really want is
the last-configured size of the toplevel window.
Since we don't properly track this anymore in the generic MetaWindow,
use XGetWindowAttributes to fetch a server-side rectangle. This is a
bad layer violation, but since the window geometry code will have to
be rewritten anyway for the Wayland set_window_geometry, let's just
push a hacky fix for now.
Struts are defined in terms of screen edges, so expand the rectangles
we get via set_builtin_struts() accordingly. However we do want to
allow chrome on edges between monitors, in which case the expansion
would render an entire monitor unusable - don't expand the rectangles
in that case, which means we will only use them for constraining
windows but ignore them for the client-visible _NET_WORKAREA property.
https://bugzilla.gnome.org/show_bug.cgi?id=730527
Like the _NET_WM_STRUT/_NET_WM_STRUT_PARTIAL client properties,
_NET_WORKAREA is defined in terms of screen geometry rather than
taking individual monitors into account. However we do want to
allow system chrome to be attached to a monitor edge rather than
a screen edges under some circumstances. As not all clients can
be assumed to deal gracefully with the resulting workarea, use
those "struts" only internally for constraining windows, but
ignore them when exporting _NET_WORKAREA.
https://bugzilla.gnome.org/show_bug.cgi?id=730527
Since commit 8b2b65246a, we assume that the compositor always
exists. Alas, the assumption is wrong - the compositor is currently
initialized after the screen, but meta_screen_new() itself may
call a compositor function if initialization involves a workspace
switch (which will happen when meta_workspace_activate() is called
more than once and for different workspaces - or in other words,
when _NET_CURRENT_DESKTOP is set and not 0).
So carefully split out the offending bits and only call them after
the compositor has been initialized.
https://bugzilla.gnome.org/show_bug.cgi?id=731332
If we have a tree of a window, a non-attached dialog, and then an
attached dialog, we want to move the second window, not the attached
dialog or the topmost. In other words, we want to move the first
non-attached window, or the first "freefloating window".
This happens in Firefox, whose Preferences dialog is freefloating,
but suboptions of those are modal dialogs.
Stupid apps fullscreen themselves by resizing the client window to
monitor size. A monitor-sized frame rect on the other hand is perfectly
normal on monitors without struts - stop force-fullscreening those
and catch the real baddies instead.
https://bugzilla.gnome.org/show_bug.cgi?id=730681
When opening the window menu without an associated control - e.g.
by right-clicking the titlebar or by keyboard - using coordinates
for the menu position is appropriate. However when the menu is
associated with a window button, the expected behavior in the
shell can be implemented much easier with the full button geometry:
the menu will point to the center of the button's bottom edge
rather than align to the left/right side of the titlebar as it
does now, and the clickable area where a release event does not
dismiss the menu will match the actual clickable area in mutter.
So add an additional show_window_menu_for_rect() function and
use it when opening the menu from a button.
https://bugzilla.gnome.org/show_bug.cgi?id=731058
This can happen since we select for events on the root window, and
clients themselves might not select for input, meaning the X server
will bubble up. Just do nothing and ignore the event in this case.
This should hopefully fix some of the
Window manager warning: Log level 8: meta_window_raise: assertion '!window->override_redirect' failed
Window manager warning: Log level 8: meta_window_focus: assertion '!window->override_redirect' failed
spam that people have been seeing.
Since we often call meta_window_move_resize_now immediately after
mapping a window, we need to make sure that the placed coordinates
are saved in the unconstrained_rect. Ideally, placement positions
wouldn't be part of the constraints system, but instead are just
done inside meta_window_move_resize_internal as part of a special
path.
We're still working out the kinks of one large-scale refactor, so
it's best not to do another one while the first is going on. This
would be a great future cleanup, though: untangling constraints
and placement, alongside the force_placement state machine and
friends.
For Wayland, we want to have everything possible in terms of the frame
rect, or "window geometry" as the Wayland protocol calls it, in order
to properly eliminate some flashing when changing states to fullscreen
or similar.
For this, we need to heavily refactor how the code is structured, and
make it so that meta_window_move_resize_internal is specified in terms
of the frame rect coordinate space, and transforming all entry points
to meta_window_move_resize_internal.
This is a big commit that's hard to tear apart. I tried to split it
as best I can, but there's still just a large amount of changes that
need to happen at once.
Expect some regressions from this. Sorry for any temporary regression
that this might cause.
We have two different coordinate spaces here. One is the rectangle
returned by meta_window_get_frame_rect, which is called the "frame
rect" or "the window geometry", which includes visible frame borders
but not invisible frame borders. The other is "frame->rect" which
corresponds to the frame's server geometry. That is, it includes
both visible and invisible frame borders.
These two were of course the same until we introduced invisible
frame borders, and an executive decision was made to make
meta_window_get_frame_rect return the rectangle bounding the
visible portions of the frame.
As time went on, the "frame rect" turned out to be more useful when
making decisions upon, since the user often doesn't think about the
invisible window geometry as part of the window.
We already calculate what amounts to the "frame rect" in the theme
code, so just change META_CORE_GET_FRAME_RECT to consume that
directly.
Since we're going to be calling meta_window_get_frame_rect in here
soon, I'd rather it be one method call, rather than two. We can't
put it at the toplevel, since that might cause infinite recursion
(e.g. meta_core_get calls meta_window_get_frame_rect calls
meta_ui_get_frame_borders calls meta_core_get, ...)
Now that meta_window_move_resize and friends act in frame rect
coordinates, we need to convert the initial grab_anchor_window_pos
storage to be in frame rect coordinates as well.
This makes Alt+F7 / Alt+F8 work respectively under X11 nested mode.
For the native backend implementation, we'll need a special Clutter
function, so don't implement that for now.
The last commit added support for the "appmenu" button in decorations,
but didn't actually implement it. Add a new MetaWindowMenuType parameter
to the show_window_menu () functions and use it to ask the compositor
to display the app menu when the new button is activated.
https://bugzilla.gnome.org/show_bug.cgi?id=730752
We want to synchronize the button layouts of our server side
decorations and GTK+'s client side ones. However each currently
may contain buttons not supported by the other, which makes this
unnecessarily tricky.
So add support for a new "appmenu" button in the layout, to display
the fallback app menu in the decorations.
https://bugzilla.gnome.org/show_bug.cgi?id=730752
meta_window_get_position() returns the client rect position, which
we then pass to meta_window_move_frame. Just use the existing frame
rect coordinates.
The requested_rect is a strange name for it, because it's not actually
the rect that the user or client requested all the time: in the case of
a simple move or a simple resize, we calculate some of the fields
ourselves.
To the MetaWindow subclass implementations, it just means "the rect
before we constrained it", so just use the name unconstrained_rect.
This also makes it match the name of the MetaWindow field.
It looks weird to have Alt+Space pop up under the cursor instead
of the top-left corner of the window, and the Wayland request will
pass through the coordinates as well.
Add it to the compositor interface, and extend the
_GTK_SHOW_WINDOW_MENU ClientMessage to support it as well.
On X, basing the check whether the pointer is on the window on
Clutter events does not work, as the relevant events are handled
by GDK instead.
So add an X-specific window_has_pointer() implementation to also
fix mouse mode when running as X compositor.
https://bugzilla.gnome.org/show_bug.cgi?id=730541
Using clutter_actor_has_pointer() to test whether the pointer is
on the window makes for clean and nice-looking code, but does not
work in practice - ClutterActor:has-pointer is not recursive, so
we miss when the pointer is on the associated surface actor rather
than the actor itself.
Instead, check whether the window actor contains the core pointer's
pointer actor, which actually works.
https://bugzilla.gnome.org/show_bug.cgi?id=730541
Otherwise, the X server might read the backend's connection before
GTK+'s, meaning that it sees the XIGrabKeycode requests before the
CreateWindow.
This fixes keybindings on windows not working immediately.
Thanks to Rui Matos <tiagomatos@gmail.com> and
Julien Cristau <jcristau@debian.org> for helping track down the issue.
Realistically, the user rect contains the unconstrained window
rectangle coordinates that we want to be displaying, in case
something in the constraints change.
Rename it to the "unconstrained_rect", and change the code to always
save it, regardless of current state.
When metacity was originally being built, the purpose of the user
rect was a lot less clear. The code only saved it on user actions,
with various other calls to save_user_window_placement() and a force
mechanism sprinkled in to avoid windows being snapped back to odd
places when constraints changed.
This could lead to odd bugs. For instance, if the user uses some
extension which automatically tiles windows and didn't pass
user_action=TRUE, and then the struts changed, the window would be
placed back at the last place a user moved it to, rather than where
the window was tiled to.
The META_IS_USER_ACTION flag is still used in the constraints code
to determine whether we should allow shoving windows offscreen, so
we can't remove it completely, but we should think about splitting
out the constrainment policies it commands for a bit more
fine-grained control.
https://bugzilla.gnome.org/show_bug.cgi?id=726714
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.
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.
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.
If we apply a prediction immediately instead of queueing, we should
also free the operation immediately.
If we discard the prediction queue because we resync fully, we
need to free each operation too.
https://bugzilla.gnome.org/show_bug.cgi?id=729732
If we exit early as not handled, then the normal process_event
handler will fire, and trigger the overlay-key binding. As that's
a special binding that doesn't have a handler, trying to trigger
that handler will crash mutter.
Instead of returning early, just check for xdisplay every time
we try to drive the X grab state machine. We really need a better
solution for this on the Wayland side.
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).
We need the old rect for two purposes: to find the x/y in a resize-only
action, and to pass into the constraints code for nefarious purposes.
The constraints code takes a frame rectangle, so we convert the original
client rect into a frame rect, but never convert it back since it's
unused for the rest of the function.
Instead of playing games with the variables, just have two,
separately-scoped variables. One is the client rect, the other is the
frame rect.
For gravity-based resizing, we need to make sure that the requested
rectangle has the proper x/y position given by the gravity resize,
rather than the bogus root_x_nw / root_y_nw parameter.
Make the test for this more explicit.
With our surface_mapped strategy, implement_showing might not
change whether the window has been shown or not, and thus we
might end up clearing pending_compositor_effect before the window
is mapped.
Only clear pending_compositor_effect when the effect has actually
been used.
Remove extend_by_frame and unextend_by_frame. Use a dumb hack in
window.c to translate into window geometry in back. We'll soon track
all rectangles in MetaWindow in terms of the window geometry.
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.
Now that we have a global MetaScreen, we can simply have a global
MetaCursorTracker as well. Keep the get_for_screen() API around for
compatibility, though.
The Alt+F7 and Alt+F8 keybinds for moving and resizing windows allow you
to move and resize the window off the screen, so allow the same for the
menu items as well, since they're marked with the same accelerator.
https://bugzilla.gnome.org/show_bug.cgi?id=728617
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 entire point of it was to check whether the window was on the
right screen. Since we don't handle multiple screens anymore, we
don't need to check anything anymore.
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.
We track changes to windows fullscreen state and stacking order
to determine a monitor's in-fullscreen state, but missed the
obvious case of moving a fullscreen window between monitors.
https://bugzilla.gnome.org/show_bug.cgi?id=728395
Commit 585fdd781c not only removed the tabpopup, but set invalid
handlers (a.k.a. NULL) for those shortcuts; add back handling of
basic handling of those shortcuts by switching instantly without any
popups.
https://bugzilla.gnome.org/show_bug.cgi?id=728423
dx/dy should be against the regular window's rect, and need to
be ignored when we're resizing. Instead, we use gravity to anchor
the window's new rectangle when resizing.
Doing this synchronously means that zenity tries to initialize GTK+.
Under Wayland, that will try to connect back to mutter as a display
server. We're waiting on zenity to exit, and zenity is waiting for
a connection response. Deadlock.
Simply assume that zenity will support all the options we feed it,
since it should be the correct version. Perhaps we should replace
our use of zenity with a simple helper binary that we know will
have all the right options if this still isn't good enough.
Our focus stealing prevention is still mostly inherited from metacity;
in particular, a (non-transient) window that is not on the current
workspace will not be given focus. This behavior made sense in the
GNOME 2 days, where workspaces were separated much more strictly.
However this is no longer the case in GNOME 3 - activating a launcher
will switch workspaces if necessary, and so will the app switcher.
There is no good reason to not do the same for other user actions
like clicking a URL or activating a search result, so allow activation
of windows on non-active workspaces if a proper timestamp is supplied,
assuming that this is a strong enough indication that we are dealing
with a legitimate user action.
https://bugzilla.gnome.org/show_bug.cgi?id=728018
Effectively we have been accepting CurrentTime timestamps for years,
but still complained about "stupid pagers" when encountering them;
just accept that we will never limit treating 0 timestamps as current
time to pagers.
https://bugzilla.gnome.org/show_bug.cgi?id=728018
The code that restacks X11 windows at the end first tracks any
old windows we know about, and then handles any windows created.
It starts when it ended, and then walks forwards and then
back looking for the first X11 window it doesn't know about.
However, when there aren't any X11 windows, it flies off the end
of the array and starts looking through random memory.
When it finds the X11 window, it then goes through and then tries
to restack the remaining windows according to how we've sorted
them.
Unfortunately, META_WINDOW_CLIENT_TYPE_X11 is 0, which is quite
common in random memory we have lying around, so we enter that
path and then just crash.
Fix the buffer overrun by adding the proper bounds check to the
search.
You can easily reproduce this by opening a menu while bloatpad
is full-screen. Why it only crashes when full-screen and not
when a standard window, I have no idea.
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.
Except while reading _NET_WM_WINDOW_OPACITY, opacity is between 0 and 255. With
guint8, we'll get compiler warnings if arbitrary int values are passed.
https://bugzilla.gnome.org/show_bug.cgi?id=727874
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.
The make_toplevel / window_unmanaging interface has never made
a lot of sense to me. Replace it with set_window, which does
effectively the same thing.
It's still not perfect in the case of XWayland, but I don't think
XWayland will ever make me happy.
Right now this just has all of the files in one directory. We'll
be introducing more structure to this in the future, and build
a proper backend system.
This will allow us to have a MetaCursorReference 'subclass' that's
lazily loaded. We currently always load all the images.
The long-term plan is to have a subclass for each "backend" and only
have CoglTexture as a common denominator. For the nested X11 backend,
we use XDefineCursor on our stage window. For the Wayland backend, we
would use set_cursor on our stage surface. For the native backend, we
would use the GBM code that's there right now.
The CoglTexture is there to be a "shared fallback" between all devices,
and also for the get_sprite API.
The odd man out is the X11 compositor case. For that, we need to move
the responsibility of setting the final cursor image out of
MetaCursorTracker, and simply have it be about tracking the used sprite
image and pointer position.
We want to make this private, and have MetaCursorReference be
backend-defined, with the texture possibly loaded on demand.
We can't make the definition of MetaCursorReference truly private yet
because of the XFixes cursor. A victim of MetaCursorTracker trying to
do too many things at once...
I want the MetaCursorTracker to mostly be about retrieving cursor
information. Start moving the code that loads cursor images to a
new file, MetaCursor. Eventually, MetaCursorTracker's APIs will
all take MetaCursorReferences, and we can have a clean backend
split here.
For whatever reason, this hash table was in the generic
implementation section instead of the XSync implementation,
even though it's only used by the XSync implementation.
Use it as a first pass of things to move over.
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.
Really, visible_to_compositor means that the window is shown, e.g.
not minimized. We need to be using a boolean tracking whether we've
called meta_compositor_add_window / meta_compositor_remove_window.
This fixes a jump during window placement when a window appears.
visible_to_compositor should always be in sync with show_window /
hide_window calls, even when unmananging.
This fixes a crash where we call sync_window_state when the window
is unmanaging, since we use visible_to_compositor to determine whether
the compositor will crash.
This is actually wrong; we should be using the knowledge about
whether we have called add_window / remove_window. We'll introduce
this with a new boolean next time.
Compositors haven't been able to manage more than one screen for
quite a while. Merge MetaCompScreen into MetaCompositor, and update
the API to match.
We still keep MetaScreen in the public compositor API for compatibility
purposes.
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.
When I refactored this out into a vfunc, I forgot to change the
code that interprets the result flags to actually respect the
new FRAME_SHAPE_CHANGED result flag.
Since we weren't ever clearing the frame bounds, this meant that
the "shadow clip" wasn't ever updated as a result. Since right now
all Wayland surfaces are considered ARGB32, we always clip shadows
under frames, and thus shadows had this weird "punch-out" from the
first frame shape.