A window's unconstrained_rect is essentially just the target rectangle
we hand to meta_window_move_resize_internal() except it's not updated
until the window actually moves or resizes.
As such, for wayland client resizes, since they're async, using
window->unconstrained_rect right after calling move_resize_internal()
to update the grab anchor position on unmaximize doesn't work as it
does for X clients.
To fix this, we can just use the target rectangle for the grab
anchor. Note that comment here was already wrong since it says we
should be taking constraints into account and yet the code used the
unconstrained rect anyway.
https://bugzilla.gnome.org/show_bug.cgi?id=770345
In order for the compositor plugin to be able to animate window size
changes properly we need to let it know of the starting and final
window sizes.
For X clients this can be done synchronously and thus with a single
call into the compositor plugin since it's us (the window manager)
who's in charge of the final window size.
Wayland clients though, have the final say over their window size
since it's determined from the client allocated buffer.
This patch moves the meta_compositor_size_change_window() calls before
move_resize_internal() which lets the compositor plugin know the old
window size and freezes the MetaWindowActor.
Then we get rid of the META_MOVE_RESIZE_DONT_SYNC_COMPOSITOR flag
since it's not needed anymore as the window actor is frozen and that
means we can use meta_compositor_sync_window_geometry() as the point
where we inform the compositor plugin of the final window size.
https://bugzilla.gnome.org/show_bug.cgi?id=770345
mutter would remove focus from a toplevel when showing one of its
transient window which is not on top and not focused.
When using xdg_popup without grab as allowed in xdg_shell v6, the popup
wouldn't be focused, and if an intermediate event occurs before the
popup is shown, it's not placed on top either, which could randomly
trigger a loss of focus in the corresponding toplevel window.
Remove that special case, it doesn't make much sense to globally unset
focus when mapping a new window.
https://bugzilla.gnome.org/show_bug.cgi?id=773210
GNOME Shell's window matching currently fails frequently with Flatpak
applications, as one of the primary hints used to link windows with
.desktop files - the WM_CLASS - no longer matches when flatpak renames
the exported .desktop file. Luckily, Flatpak provides us with a fail-safe
way to map from the PID to the corresponding application ID, so expose an
appropriate method that allows GNOME Shell to reliably match windows to
the corresponding Flatpak app.
https://bugzilla.gnome.org/show_bug.cgi?id=772614
It is often useful to identify the client process that created
a particular window, however the existing meta_window_get_pid()
method relies on _NET_WM_PID, which is only available on X11 and
depends on applications to set it correctly (which may not even
be possible when the app runs in its own PID namespace as Flatpak
apps do). So add a get_client_pid() method that uses windowing
system facilities to resolve the PID associated with a particular
window.
https://bugzilla.gnome.org/show_bug.cgi?id=772613
When a modal transient is unmanaging, most likely the parent of the
modal transient should be focused.
In Wayland, a MetaWindow is created when a shell surface role (like
xdg_toplevel) is created, but a window cannot be shown until a buffer
is attached. If a client would create two modal transients and make
them both have the same parent, but only one get a buffer attached
(i.e. shown), when unmanaging the modal transient that was showing,
when finding a new focus candidate, the stacking code will ignore the
not-to-be-shown buffer-less modal transient when finding a good
candidate for focusing. In the case described here, this means it will
find the parent of the unmanaging modal transient.
This newly chosen candidate will then be passed to meta_window_focus();
meta_window_focus() will then try to find any modal transient to focus
instead, will find the one without any buffer, then fail to focus it
because it cannot be mapped, thus making meta_window_focus() not focus
anything. Since meta_window_focus() didn't change any focus state, the
assert in meta_window_unmanage() checking that the unmanaging window
isn't focused anymore will be hit, causing mutter to abort.
For now, fix this by checking whether the modal transient can actually
be focused in meta_window_focus(). For X11 client windows, a window
will be defined to be focusable always, but for Wayland client windows,
a window will be determined focusable only if it has a buffer attached.
In the future, we should probably do a more thorough refactorization of
focus handling to get rid of any X11 - Wayland differences.
https://bugzilla.gnome.org/show_bug.cgi?id=757568
Even without a compositor grab, key events may still be expected to
be processed by the compositor and not applications, for instance
when using ctrl-alt-tab to keynav in the top bar. On X11, focus is
moved to the stage window in that case, so that events are processed
before they are dispatched by the window manager. On wayland, we need
to handle this case ourselves, so make sure to not pass key events to
wayland in that case, and move the key focus back to the stage when
appropriate.
https://bugzilla.gnome.org/show_bug.cgi?id=758167
For some reason, when a modal dialog was made an attaching
transient-for, if the window wasn't "constructing", it would be
unmanaged and rely on some side effect to be recreated. This side
effect is not triggered for Wayland clients, thus if one happen to set
a surface as "modal" via gtk_surface.set_modal before
xdg_toplevel.set_parent, it'd be unmanaged and never show up.
Instead, simply just set the tranciency anyway for Wayland clients.
This makes GTK+ clients that set_modal() before set_transient_for()
work.
https://bugzilla.gnome.org/show_bug.cgi?id=770324
Windows from Xwayland still needs to use the Wayland path, but is
represented an MetaWindowX11, thus the abstraction introduced in
"window: Make meta_window_has_pointer() per protocol implemented"
is wrong. Lets turn back time, and reconsider how this can be
abstracted more correctly in the future.
This reverts commit 9fb891d216.
Add support for assigning a window a custom window placement rule used
for calculating the initial window position as well as defining how a
window is constrained.
The custom rule is a declarative rule which defines a set of parameters
which the placing algorithm and constrain algorithm uses for
calculating the position of a window. It is meant to be used to
implement positioning of menus and other popup windows created via
Wayland.
A custom placement rule replaces any other placement or constraint
rule.
https://bugzilla.gnome.org/show_bug.cgi?id=769936
This layer isn't really being used and in fact, it causes
meta_stack_get_default_focus_window() to return a fullscreen window
even if the naturally topmost window in the stack isn't a fullscreen
one.
Note that commit a3bf9b01aa changed how
we choose the default focus window from the MRU to the topmost in the
stack.
https://bugzilla.gnome.org/show_bug.cgi?id=768221
printf string precision counts bytes so we may end up creating invalid
UTF-8 strings here. Instead, use glib's unicode aware methods to clip
the title.
https://bugzilla.gnome.org/show_bug.cgi?id=765535
If we try to send notify event (either from surface_state_changed()
or from meta_window_wayland_move_resize_internal()),
we will crash, because we don't have a sufrace anymore.
There's no reason why to resize the window that is being
unmanaged anyway.
https://bugzilla.gnome.org/show_bug.cgi?id=751847
Each wl_surface.commit with a newly attached buffer should result in
one wl_buffer.release for the attached buffer. For example attaching
the same buffer to two different surfaces must always result in two
wl_buffer.release events being emitted by the server. The client is
responsible for counting the wl_buffer.release events and be sure to
have received as many release events as it has attached and committed
the buffer, before reusing it.
https://bugzilla.gnome.org/show_bug.cgi?id=762828
If a broken or naughty application tries set up its windows to create
a loop in the transient relationship, mutter will hang, looping forever
in meta_window_foreach_ancestor()
To avoid looping infinitely at various point in the code, check for a
possible loop when setting the transient relationship and deny the
request to set a window transient for another if that would create a
loop.
Bugzilla: https://bugzilla.gnome.org/show_bug.cgi?id=759299
The new tiling code, instead of based around "tiling states", is instead
based around constrained edges. This allows us to have windows that have
three constrained edges, but keep one free-floating, e.g. a window tiled
to the left has the left, top, and bottom edges constrained, but the
right edge can be left resizable.
This system also is easily extended to support corner tiling. We also,
using the new "size state" system, also keep normal, tiled, and
maximized sizes independently, allowing the maximize button to bounce
between maximized and tiled states without reverting to normal in
between. Dragging from the top will always restore the normal state,
though.
https://bugzilla.gnome.org/show_bug.cgi?id=751857
In case a window is hidden when we're ordered to make it transient to
a different parent we must re-evaluate its visibility status or we'll
get into an inconsistent state where the parent is visible and the
child isn't.
https://bugzilla.gnome.org/show_bug.cgi?id=759297
This seems like a more generally useful and intuitive behavior. Note
that, in X sessions, this is what already happened in practice since
meta_display_begin_grab_op() calls meta_window_grab_all_keys() which,
on X11, does meta_window_focus().
https://bugzilla.gnome.org/show_bug.cgi?id=756789
Don't update the stack until after setting the window->transient_for
field. Updating before will cause the stack transient-for constraint to
be missing until the next time constraints are applied.
https://bugzilla.gnome.org/show_bug.cgi?id=755606
Wine removes the minimize func from its Motif hints on full-screen
windows, because, as the Win32 API literally says, the minimize button
is indeed not visible on full-screen windows.
Given that this code was added to prevent minimizing a panel by
accident, I don't necessarily think that it's relevant anymore.
https://bugzilla.gnome.org/show_bug.cgi?id=758186
When managing window, we queue showing the window.
Under wayland, if we commit surface quickly enough,
the showing is unqueued and commit procedure takes care
of mapping and placing the window. In the oposite case,
queue is processed before client sets all we need and
then we have wrong size of window, which leads to broken placement.
Therefore force placement in queue only if the window should already
be mapped. If it is not mapped, we don't care where it is anyway.
https://bugzilla.gnome.org/show_bug.cgi?id=751887
Displaying all Wayland windows with the XID of 0x0 makes it hard
to figure out what is going on ... use the recently-added
window->stamp to show Wayland windows as W1/W2/W3...
This was introduced in commit c6793d477a
to prevent window self-maximisation. It turns out that that bug seems
to have been fixed meanwhile in a different way since the reproducer
in https://bugzilla.gnome.org/show_bug.cgi?id=461927#c37 now works
fine with this special handling removed.
In fact, failing to set window->fullscreen immediately when loading
the initial set of X properties causes us to create a UI frame for a
window that sets _NET_WM_STATE_FULLSCREEN.
This, in turn, might cause the fullscreen constrain code to fail if
the window also sets min_width/min_height size hints to be the monitor
size since the UI frame size added to those makes the rectangle too
big to fit the monitor. If the window doesn't set these hints, we
fullscreen it but the window will get sized such that the UI frame is
taken into account while it really shouldn't (see the reproducer
above).
https://bugzilla.gnome.org/show_bug.cgi?id=753020
Since we scale surface actors given what main output their toplevel
window is on, also scale the window geometry coordinates and sizes
(window->rect size and window->custom_frame_extents.top/left) in order
to make the window geometry represent what is being rendered on the
stage.
https://bugzilla.gnome.org/show_bug.cgi?id=744934
The main monitor of a window is maintained as 'window->monitor' and is
updated when the window is resized or moved. Lets avoid calculating it
every time it`s needed.
https://bugzilla.gnome.org/show_bug.cgi?id=744934
A much less hacky version of maximize / unmaximize is reimplemented
in terms of this, but it could also eventually be used for fullscreen /
unfullscreen, and tile / untile.
This is an extremely niche feature, and conflicts with the rest of our
interface being consistent about not allowing resizing while tiled or
maximized.
Going from fullscreen to unfullscreen involves a frame border size, so
in order to properly interpret the saved rect size, we need to make sure
that the frame borders are fully up to date.
The "calc showing" operation is queued in a few places alongside MetaWindow
creation, we should be ignoring these until there is a buffer to show.
https://bugzilla.gnome.org/show_bug.cgi?id=750552
In order to switch to the correct surface actor scale given the monitor
the surface is on, without relying on the client committing a new state
given some other side effect, sync the surface actor state when the main
monitor associated with the corresponding window changed.
https://bugzilla.gnome.org/show_bug.cgi?id=744933
Returning FALSE here gets the button release event propagated to the
client on wayland, which is unexpected after xdg_surface.move/resize()
have been called.
https://bugzilla.gnome.org/show_bug.cgi?id=738888
Fullscreen windows look weird when they are overlapped by system chrome,
which currently happens when another window is stacked above. We used to
auto-minimize fullscreen windows in that case, which proved to be both
unreliable and unpopular. So instead, keep the system chrome hidden even
when the fullscreen window is not stacked at the top.
https://bugzilla.gnome.org/show_bug.cgi?id=693991
In Wayland, popup window types are not override-redirect, and thus can
steal window focus away from their parent window when clicked on.
This means that we need to make sure their appearance is properly
propagated to the parent windows so the parent windows don't lose their
focus while they're propagated.
We only grant requests to set the demands-attention hint if the window
is at least partially obscured; so for non-minimized windows on the
active workspace, we check if any other window on the same workspace
that is higher in the stack overlaps.
However in the case of a sticky window, window->workspace is NULL, so
we end up considering any non-sticky window on a different workspace.
At this point we have already established that the window is showing
on the active workspace, so use that to filter for windows that may
overlap.
Since the introduction of set_workspace_state(), window->workspace
will always be NULL when on_all_workspaces is set - passing that
to a workspace function that does not validate its input will then
result in a crash.
Use the get_workspace() function instead, which will always return
a valid workspace.
Since commit 2eec11b445, windows without a __NET_WM_DESKTOP property
that should be on all workspaces are not added to the active workspace;
this is correct, however not adding them to any workspace is not ...
set_workspace_state () returns early when the desired sticky state
and workspace match the current property values, assuming that the
corresponding MRU lists are already correct in that case.
However that might not be the case when we are setting the initial
state, so don't take the shortcut in that case.
https://bugzilla.gnome.org/show_bug.cgi?id=737178
A window may either be sticky because it has been requested as such,
or because it is placed on a non-primary monitor (and the corresponding
preference is set). While we do take the latter into account, we
currently override the sticky state later during initialization;
be a bit more careful there to get the initial state right.
https://bugzilla.gnome.org/show_bug.cgi?id=737178
The titlebar rect is in window coordinates, while screen regions are
obviously not. Fix by translating into screen coordinates before
testing for overlaps.
https://bugzilla.gnome.org/show_bug.cgi?id=736915
Putting X windows and pointers to MetaWindows into a union had a number of
problems:
- It caused awkward initialization and conditionalization
- There was no way to refer to Wayland windows (represented by
MetaWindow *) in the past, which is necessary for the MetaStackTracker
algorithms
- We never even cleaned up old MetaStackWindow so there could be
records in MetaStackWindow pointing to freed MetaWindow.
Replace MetaStackWindow with a 64-bit "stack ID" which is:
- The XID for X Windows
- a "window stamp" for Wayland windows - window stamps are assigned
for all MetaWindow and are unique across the life of the process.
https://bugzilla.gnome.org/show_bug.cgi?id=736559
We can enter weird states where get_default_window is called during
window unmanagement, before the window has been fully removed from
the stack. Make sure these windows are *never* returned from
get_default_window, as focusing them can cause an assertion fail,
or worse.
A lot of applications assume that the window is fully positioned when it
gets the MapNotify, especially simple applications. Make sure that the
window is only mapped through the calc_showing logic.
This is bad behavior, and can also cause us to get in an infinite loop
if an OR window is mapped and unmapped in quick succession. This
sequence causes a MapNotify followed by an UnmapNotify, and when
processing the events, we'll call XMapWindow, XUnmapWindow, which will
put another set of MapNotify, UnmapNotify events in our queue, which we
then process by calling XMapWindow, XUnmapWindow, and so it goes
forever, or at least some scheduler uncorks us by making us call
XMapWindow when the window is already mapped, or XUnmapWindow when the
window is already unmapped.
We can stop this madness by simply making sure never to call neither
XMapWindow or XUnmapWindow on OR windows, which is the correct thing to
do anyway.
In gnome-shell, we have a feature where the user can unmaximize windows
by dragging them from the panel above the window. With accurate
anchoring, this looks really weird as the cursor is now "detached" from
the window. Detect this case and put the cursor in the middle of the
window titlebar instead.
This seems to be more accurate with what we currently see in
GNOME. Without having the app expose this information to us, it might be
a better idea to use the default frame style for this information instead.
The cursor was anchored wrongly when trying to unmaximize windows from
dragging them from the top of the screen because of a few think-o's and
some code that forgot to be updated when we moved to the frame rect
coordinate system.
The cursor is still offset for windows that start dragging from the top
panel. This is technically correct, but looks wrong. We'll fix this in
the next commit.
The existing workspace management code is quite hairy, with plenty of
logic inline in all of window.c, workspace.c, and screen.c, making it
hard to understand or make changes to, since you might forget to change
several of the other places the code was around.
Rewrite the internal workspace management logic so that it's
centralized and all in window.c. Document the invariants we need to
maintain, and ensure that these invariants are properly kept, with
asserts in various places.
Extensive testing on gnome-shell did not bring up any issues, and this
is a considerable cleanup.
MetaGrabOp is painful and tedious to work with, because it's a
sequential series of values, meaning we have to use a giant unreadable
switch statement to figure out some basic things about the value.
To solve this, modify the encoding for MetaGrabOp and for the specific
window grab operations so that they're a set of bitflags that we can
easily check.
It turns out that Clutter doesn't actually filter NumLock / ScrollLock /
CapsLock from button events due to its terrible event translation code.
Check only the grab mods to check if it's unmodified.
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.
This is an accidental regression from 7a109a1. If we mark the event as
handled, then we *need* to set grab_op, or do some other sort of
behavior, since we have a grab.
On X11 this works because only emulated pointer events are listened for. On
wayland, the single touch behavior must be enforced in touch events, ignoring
every other sequence.
https://bugzilla.gnome.org/show_bug.cgi?id=733631
When a Wayland window acks our arrangement and we don't really have
anything to modify, we'll pass a sole flag of META_IS_WAYLAND_RESIZE
to meta_window_move_resize_internal using a garbage rect. The existing
code to calculate the new rectangle couldn't really handle this case,
and so the garbage rectangle accidentally got stored. Revamp the flag
checks to be more clear about it.
This fixes the weird positioning issues that sometimes appear when
resizing weston-terminal among others.
This code was supposed to refresh our default icons when the theme
changed, but it actually was a no-op, since the default icons are cached
in a static variable in MetaUI.
I'm not sure the fact that the fallback icons don't update when the
theme changes is an important enough use case to keep working, but I'm
keeping the skeleton function there in case somebody wants to actually
fix it properly.
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>
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".
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.
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.
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
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.
