While findWorkingCombination should never fail, in the case it does
KWin should not crash. To achieve that simply restore the old config
in case of failure.
CCBUG: 439873
When libinput tears down, it may access the Session object. This change
re-jitters the shut down logic so the Session object is guaranteed to be
valid when libinput stuff gets destroyed.
BUG: 442104
ksmserver provides the backing window (the hidden black one) for the
lockscreen. We don't want to animate this fading out.
It no longer provides the logout prompt since several plasma releases.
DrmGpu::updateOutputs is now changing the state of some drm properties
without changing the fitting output state (namely RenderLoop inhibition)
which can lead to rendering being inhibited indefinitely in some cases
Software-based clipping is naive. It maps the clip region from the
global screen coordinates and intersects it with window quads. If the
window is transformed, the quads won't be clipped as expected.
Unfortunately, the OpenGL scene enables software-based geometry clipping
if the screen transformed. It's not clear why it does so, perhaps as a
performance optimization? Either way, this produces incorrect results
when the screen is scaled.
BUG: 440940
This makes ExpoLayout easier to maintain. As is, the main issue with it
is the number of layout algorithms.
With this, the ExpoLayout is going to have two layout algorithms - one is
very simple and the other not so.
Startup code in plasmashell was changed so xsetroot is not called
anymore, which is sort of fine.
Unfortunately (or not?), it exposed a bug in kwin. Cursor::x11Cursor()
only works in the standalone X11 session.
On Wayland, Cursor::x11Cursor() will return XCB_NONE which results in
seeing cross cursor when there should be arrow cursor.
This change moves xcb_cursor_t look up code from X11Cursor to the base
Cursor class. In hindsight, I would like to introduce a window manager
class where the xcb cursor and other x11 specific code can be moved in
the future for better encapsulation of platform-specific code.
CCBUG: 442539
For some reason, layers are change after applying Show Desktop effect, so
we will have AboveLayer for our popups and Desktop, and NotificationLayer
for Dock which hides us.
Also, OSD and critical notifications were always hidden by our popups.
This patch solves both the issues.
Usual notifications will still be hidden, but hopefully it's not a big
issue.
BUG: 442605
reinterpret_cast<>() will fail if the types we cast from and to have
mismatching sizes.
Unfortunately, there are platforms that have Window and
EGLNativeWindowType of different size. This results in compilation
errors.
In order to work around those problematic platforms, this change
replaces reinterpret_cast cast with a c style cast.
EffectQuickView is used by Aurorae. As long as Aurorae decorations are
rendered by kwin, it's not a problem. However, kde-gtk-config kded
module can also render them. This creates a problem. If effects object
is not created, accessing any of its getters or setters will result in a
segmentation fault.
This change rewrites the share context check so the effects object is
not accessed anymore.
One could argue that kde-gtk-config has to provide a dummy EffectsHandler
but it doesn't use effects and libkwineffects is not a dependency of
KDecoration2. So, providing a dummy EffectsHandler makes no sense.
In hindsight, we need to revisit the usage of EffectQuickView in Aurorae
as accessing the EffectsHandler in EffectQuickView is a totally valid
usecase and integration of QOpenGLContext.
BUG: 441585
When running in plasma, the animation speed slider is in General
Behavior KCM.
The Defaults button should not reset the animation speed slider because
it's hidden.
BUG: 442600
With per-screen rendering, the projection matrix is no longer created
with the workspace geometry, i.e. all screen geometries united, so the
center of the workspace geometry may not map to (0, 0) in the clip
coordinates.
GLRenderTarget::virtualScreenGeometry() can be used to query the rect
that was used to create the projection matrix.
BUG: 442770
KMS can only ever have one frame pending at the moment. If we
update the outputs while a pageflip is still pending on any output
the atomic commit will fail with EBUSY, which both invalidates
the testing for output configuration and makes applying the wanted
configuration fail.
This can be removed again once KMS gains the ability to do mailbox
presentation; that will likely still take a while though.
BUG: 442677
Currently, data from client buffer EGLStream is copied to a surface
texture. An fbo is used for that purpose. The main issue with it is that
it doesn't restore the old framebuffer binding.
The surface texture can be updated in the middle of a compositing cycle.
If the framebuffer binding is not restored, any window that must be
rendered in an offscreen texture won't be rendered to the offscreen
texture.
This change makes EglStreamSurfaceTextureWayland restore the fbo binding
so the DeformEffect and software screen rotation work as expected with
the proprietary NVIDIA driver.
BUG: 442697
This makes the compositingPossible() output more elaborative,
and adjusts their priorities to qCWarning.
I thought about dropping the "Compositing is not possible"
(qCCritical) message. It's not critical for X11 and Wayland
depends on OpenGL. OTOH it's from a different component. So in
the end I settled for qCWarning again; there is no real way
to know, if the platform will consider this a critical problem
(and eventually abort).
Then I saw X11StandalonePlatform::compositingNotPossibleReason,
which has more user friendly, QT Richtext / HTML encoded output,
but this seems overkill for the terminal; now I would like to
know, where this is actually used...
While at it report "manually" suspended compositing via qCInfo
instead of qCDebug.
After updating my Debian buster to bullseye, I noticed missing
shadows / composite for KDE, which made overlapping windows hard
to recognize.
.xsession-errors just had "kwin_core: Compositing is not possible".
Using the suggested QT_LOGGING_RULES="kwin_*.debug=true" didn't
provide any more clues; nothing I tried did.
Eventually I ended reading the kwin source and found, that
disabled composite via kwinrc :: [Compositing] :: OpenGLIsUnsafe
was not reported.
IMHO all these disabling cases should use qCCritical(KWIN_CORE),
like the "Compositing is not possible" message, but for the time
being, this simply logs the OpenGLIsUnsafe reason, just like all
the others.
With the recent AbstractOutput changes, Workspace::clientArea() overload
that takes only the window and no additional output was changed to
return clientArea(opt, window, window->output());
prior to that, it had been looking up the output at the center of the
frame geometry.
As it turns out, AbstractOutput::sendToOutput() blocks geometry updates,
which in its turn means that Toplevel::output() will be updated only
after geometry updates are unblocked. For the most part, it's not a big
deal until you need to use Workspace::clientArea(opt, const Toplevel*)
Since the output won't be updated until geometry updates are unblocked,
clientArea(opt, const Toplevel *) may return outdated info.
One could argue that we just simply need to update m_output similar to
m_frameGeometry when geometry updates are blocked, but... it's not going
to work on wayland! On Wayland, GeometryUpdatesBlocker is totally
unnecessary. Even if a window is resized, m_frameGeometry will be left
unchanged until the client repaints the window.
Instead, one need to pass the AbstractOutput to clientArea() if it's
important.
This change makes X11Client::changeMaximize() query the MaximizeArea of
the output containing the center of the move resize geometry, similar to
what the XdgToplevelClient does.
BUG: 442534
There are some unresolved issues where driving outputs can fail because
of bandwidth constraints. These don't appear to happen with implicit
modifiers, or at least they don't happen as often.
libinput will send release and proximity out events after the device is
disconnected.
This just takes into account that tablet might be nullptr.
BUG: 442573
The stored geometry is irrelevant in the window is maximized.
This is especially relevant if we:
* open a virtual keyboard
* rotate the display (then it looks ok as it was already addressed)
* then remove the keyboard.
At that point we want to reset to the available area rather than the
previous.
By supporting all the required attributes in the DecorationThemeMetaData class
the custom struct can be dropped.
Task: https://phabricator.kde.org/T14744
We can just put the parameter in the variant list. Because the method is virtual, the keyword
parameter must exist in the method definition.
Task: https://phabricator.kde.org/T14744
b38bb416 introduced flicker when restarting compositing because the
DrmGpu::findWorkingCombination method usually creates new buffers for
the commit, without rendering into them. Instead of that, re-use
existing buffers where possible
The configs returned by eglChooseConfig are sorted from highest to lowest buffer sizes.
Filter the configs to find a suitable candidate that matches the requested attributes of the surface.
This fixes the corrupted Aurorae window decorations on Wayland with the proprietary Nvidia driver.
Conceptually, a configure event inherits its parent's state and adds
some of its own. This allows the compositor to skip intermediate
configure events in ack_configure handler and jump to the last one.
Currently, the only field that XdgSurfaceConfigure objects need to
inherit is flags. The geometry info and window states are filled in by
role commit implementations to their latest values.
XdgSurfaceConfigure::flags indicates if the configure event moves the
window. This flag is important to resolve conflicts between geometry
updates initiated by the user and the ones that are made in response to
acknowledged configure events, e.g. after maximizing the window, etc.
(effectively, if the user moves a window, kwin will cancel scheduled
moves in configure events)
If configure flags are not inherited, we can end up with the following
case:
* configure event A (flags: {position})
* configure event B (flags: {})
If the client acknowledges configure event B, kwin will skip configure
event A, and thus it won't move the window to the right place. This is
the root cause of fullscreen mode misbehaving with apps such as google
chrome.
discardPixmap() increases the reference counter, but there's no matching
place where the ref count is decreased, which results in the previous
pixmap not being released even if it's not needed anymore.
Instead of setting pipelines one by one, use DrmGpu::updateOutputs to
set all the outputs on a GPU with a single atomic commit. This makes
the switch both faster, more reliable and in case the other drm master
changes the output configuration, prevents blanking.
eglCreateWindowSurface() wants a Window (unsigned long), but with
EGL_NO_PLATFORM_SPECIFIC_TYPES, EGLNativeWindowType is defined as an
opaque pointer, i.e. void*.
BUG: 440372
If a property blob got created by another drm master we can't rely on
re-using it, so create a new blob of our own with the data copied over
when the kernel destroys it.
Also free property blob objects when we don't need them anymore.
BUG: 440294
At the moment we were checking for size difference between the buffers
which works for rotation but not for flipped or up-side down screens.
This changes how we check it by comparing the effective transform vs the
supported one in drm to see if they differ.
Fixes https://invent.kde.org/plasma/plasma-phone-components/-/issues/112
Do not discard a shortcut immediately when it is already registered
in KGlobalAccel, because there could be possible dangling shortcuts
if they weren't properly cleaned-up (ex. after a crash).
Instead we delay the check for conflicts with other client shortcuts
to the second loop, which we know is up to date.
BUG: 442215
FIXED-IN: 5.22.80
QSGImageNode ignores QSGTexture's filter, one has to specify it using
QSGImageNode::setFiltering().
In hindsight, we need to figure out how to integrate the lanczos filter
with window thumbnails and use it instead.
BUG: 441709
If the buffer size changes after creating or destroying the decoration,
the surface item will discard the pixmap.
If the buffer size remains the same, we can continue using old pixmap.
The current implementation sometimes will leave the screens unusable,
therefore KWIN_DRM_SW_ROTATIONS_ONLY=1 is default.
Use KWIN_DRM_SW_ROTATIONS_ONLY=0 to test hardware DRM operations.
xcb_send_event always copies 32 bytes, so we have to pad all xcb_*_event_t
to 32 bytes to avoid leaking uninitialized stack memory. I found this
problem while running kwin_x11 on a CHERI-RISC-V system (which has bounded
pointers). The xcb_send_event() implementation has a memcpy() that was
copying 32 bytes but the event passed was a bounded to 28 bytes, so this
resulted in a run-time exception in X11Client::sendClientMessage().
The same problem exists in Selection::sendSelectionNotify(), but this time
we could end up copying up to 8 bytes since xcb_selection_notify_event_t
is only 24 bytes.
This disclosure of uninitialized data could in theory have a security
impact if it leaks a pointer value (e.g. a return address) as part of an
exploit chain that needs to bypass ASLR. However, the selection notify
events go directly to the XServer and you most likely already have a
serious problem if an attacker has full control over the XServer. It is
possible that the configure notify events go directly to an untrusted
client, but even if they do this leak is not directly exploitable.
See also https://gitlab.freedesktop.org/xorg/lib/libxcb/-/issues/18
An AbstractDragTarget is introduced. This contains either the DataDevice we are
dragging to or an Xwl bridge.
We set this on Seat along with the active surface.
In future this also allows getting rid of the move filter.
If a virtual desktop has empty name, kwin is going to end up in an
infinite cycle where VirtualDesktopManager::save() updates the
_NET_DESKTOP_NAMES property and then in the next event loop cycle,
RootInfoFilter::filter() is going to call VirtualDesktopManager::save()
because the _NET_DESKTOP_NAMES property has been changed.
This regression has showed up just now because some parts of kwin used
to increase virtual desktop count to create new desktops. Recently, that
code was ported to VirtualDesktopManager::createVirtualDesktop().
The main difference between createVirtualDesktop() and setCount() is
that the latter will set the desktop name to "Desktop N", the former
will use user-specified name.
If the user-specified name is empty, the createVirtualDesktop() method
should assign "Desktop N" name to the virtual desktop according to the
docs. However, it's not the case and this change addresses that.
Not all combinations of connectors, crtcs and planes will work
on all hardware, so we need to test the pipelines before using
them.
BUG: 433107
CCBUG: 435265
In order to accomodate crtc or primary plane changes on outputs we
need to dynamically recreate rendering resources with EglStreams as
the stream is tied to the crtc or plane currently in use.
Instead of using setTransformInternal directly, have DrmOutput
set it in updateTransform, like with the other setters. Also use
updateTransform instead of setTransformInternal in DrmBackend, so
that hardware rotation can be used where possible.
This decouples the management of Shadow from the scene window and allows
multiple items share the same Shadow.
Currently, kwin has a single scene graph, but it makes sense to create a
scene graph per output as they could have different layers, etc. This
would also allow QtQuick share more textures with kwin, which is worth
doing for optimization purposes in the future.
This makes shadow texture coordinates consistent with surface and
decoration texture coords and allows reusing window quads between
kwin items and qtquick items more easily.
This allows the decoration buttons to be updated accordingly
when the status changes.
We also need to explicitely update allowed actions when rules
are applied, as `isCloseable` is not a settable property, but
an allowed action
BUG: 424370
FIXED-IN: 5.22.90
The check for this rule was missing on window initialization,
so on Wayland it wasn't being applied until something would
trigger the check again.
BUG: 429171
FIXED-IN: 5.22.90
Do not access fields in DataSourceModel::m_data that are not available
0 0x00007f3445a4bd22 in raise () at /usr/lib/libc.so.6
1 0x00007f3445a3590e in abort () at /usr/lib/libc.so.6
2 0x00007f3446362bb1 in qt_message_fatal (message=<synthetic pointer>..., context=...) at /home/apol/devel/frameworks/qt5/qtbase/src/corelib/global/qlogging.cpp:1914
3 QMessageLogger::fatal(char const*, ...) const (this=this@entry=0x7fff288a4ff8, msg=msg@entry=0x7f3446663028 "ASSERT failure in %s: \"%s\", file %s, line %d") at /home/apol/devel/frameworks/qt5/qtbase/src/corelib/global/qlogging.cpp:893
4 0x00007f344636203e in qt_assert_x(char const*, char const*, char const*, int) (where=<optimized out>, what=<optimized out>, file=<optimized out>, line=<optimized out>) at /home/apol/devel/frameworks/qt5/qtbase/src/corelib/global/qglobal.cpp:3366
5 0x00007f344973e118 in QVector<QByteArray>::at(int) const (this=0x55f42c20d338, i=7) at /home/apol/devel/kde5/include/QtCore/qvector.h:449
6 0x00007f34497305df in KWin::DataSourceModel::data(QModelIndex const&, int) const (this=0x55f42c20d320, index=..., role=6) at /home/apol/devel/frameworks/kwin/src/debug_console.cpp:1657
7 0x00007f3447674ed1 in QModelIndex::data(int) const (arole=6, this=0x7fff288a55c0) at ../../include/QtCore/../../../../../devel/frameworks/qt5/qtbase/src/corelib/itemmodels/qabstractitemmodel.h:460
no_use_linear: dropping the gbm GBM_BO_USE_LINEAR flag on allocation
explicit_modifiers: moving from the modifier-less api to the modifier
aware one with explicit modifiers
Removing (WIP) will result in more work for translators. There are other
ways to indicate the effect is not ready for its prime time yet, e.g.
being disabled by default.
Can be useful when investigating clipboard related problems, by checking
which source KWin thinks is the current clipboard. Displays clipboard and
primary selection.
Port the RuleSettings and KCM to store and use a list of virtual desktop
UUIDs, instead of the previous x11 positional id, continuing the work on
This allows to set a rule with several desktops on Wayland.
On X11 it has no visible change for the user, but internally it uses the
more modern concept, helping to simplify the related code.
The relevant key on kwinrulesrc changes from `desktop` to `desktops`.
A kconf_update script handles the migration.
The present windows allows the user to search windows by their caption
or window role. This change brings that functionality to this effect.
BUG: 441302
According to the spec, enter has to be send before position.
Sending position first seems to confuse clients, before this
change X windows only seemed to get data when the pointer left and
entered them for a second time. Now it works straight away.
BUG:437406
This lays down some groundwork for realtime gestures in Wayland,
so that gestures that are 1:1 with user motion on a touchpad are
now possible to implement.
Due to earlier commits, this is mostly just glue code to make a
convenient API.
Gestures implemented with this API are four-finger gestures, to
avoid conflicting with apps that may use two or three-finger
gestures.
The previous implementation added noise in linear space, which resulted in
the effect becoming more pronounced on black backgrounds. This patch
changes the process to be applied in perceptual space, by making the noise
addition pass a separate draw call and disabling GL_FRAMEBUFFER_SRGB during
that.
After this change, noise will look much more suppressed and almost never
grainy. This change also changes the range of the noise from
[-strength..strength) to [0..strength), as blending can only be either
additive or subtractive. As a result, users might need to ramp up their
noise parameter after this change.
v2: Add more explanation around the draw call.
v3: Fix noise not fading out with the fade out effect.
v4: Restore an accidentally removed comment.
v5: Add CCBUG.
v6: Rebase.
v7: Fix a formatting issue.
CCBUG: 409620
Originally, there was ShellClient class that was the predecessor to
WaylandClient subclasses. If the main surface is unmapped, the
corresponding instance of ShellClient would be kept around. That had
been changed with the introduction of XdgToplevelClient and
XdgPopupClient.
Since ShellClient had been kept alive even if the corresponding surface
were unmapped, it did make sense to setup window management integration
when the surface is mapped.
However, this also means that plasma will not know about initially
minimized windows.
Since unmapped windows are handled differently now, we can setup window
management after the client performs the initial commit. If the main
surface is unmapped, the XdgToplevelClient object will be destroyed and
with it, the window management integration.
Currently, ExpoLayout delays layout updates by using a singleshot timer
(primarily due to the author of the effect not being aware of
QQuickItem::polish() and QQuickItem::updatePolish()).
This change makes ExpoLayout schedule layout updates using QtQuick's
native item polish machinery, which gets triggered before rendering and
thus we can batch more geometry updates.
In addition to that, this change simplifies the initialization code in
ScreenView by making the fact that ExpoLayout is arranged right before
rendering internal to the WindowHeap type.
As all outputs from secondary GPUs are in the same map as the ones from
the primary GPU, EglMultiBackend::findBackend always returned the
primary backend. To fix that, search in secondary backends first
This is to prevent hitting the case where there are no any outputs.
Ideally, it shouldn't matter in which order outputs are added or
removed, but the Workspace and AbstractClient subclasses don't work
with true headless mode. If there are no outputs, kwin can crash.
Due to the screen edges test not being an integration test, it's very
hard to change output related code in libkwin. screens.cpp needs to have
a few ifdefs to successfully compile.
This change rewrites the screen edges test as an integration test in
order to allow us using other components of kwin in screens.cpp and
screenedge.cpp without ifdef guards.
It's not a one-to-one port.
With the new output query algorithm, position of an output may not align
with its xinerama index. This can be problem on x11 as some protocols,
e.g. startup feedback, use xinerama indices to identify outputs.
Technically, the RandR specification doesn't say that CRTCs are stored
in the xinerama order, it only mentions that the first CRTC corresponds
to the primary output. However, such assumption was made by kwin prior
to output query changes, this change merely restores that behavior.
Active output is a window management concept. It indicates what output
new windows have to be placed on if they have no output hint. So
Workspace seems to be a better place for it than the Screens class, which
is obsolete.
This allows us to drop obsolete Screens class.
Currently, the Screens class is a thin wrapper around platform outputs +
some extra tracked state, e.g. active output, workspace geometry, etc.
This is a little helper that can be very convenient with our transition
from int-based screen ids to AbstractOutput.
As is, the main issue with int screen ids is that they are extremely
dynamic.
Instead of crashing because a nullptr property gets accessed, use
an explicit error message and ignore the offending object. This also
acts as documentation
With AbstractOutput being used more heavily, it makes sense to have
something like Screens::number() in the Platform class. As is, the steps
to get an output for a given point are awkward - first, get the screen
id, then use the screen id to get the output.
With the new virtual desktop model, we have an issue where the old
code that uses desktop() needs to be ported to desktops().
However, using no desktop() is better as we don't need to deal with
cases where a window can be on several desktops, which can be annoying
sometimes.
This change removes the desktop arg in electricBorderMaximizeGeometry()
and ports it to a Workspace::clientArea() overload that requires no
desktop.
Under the hood, Workspace::clientArea() still uses desktop(), but it
could also use a different strategy to compute the client area if the
window is on several virtual desktops, e.g. intersect client area on
every virtual desktop.
There's no need to guard the code, gbm and drm format definitions
are the same. Using GBM_BO_FORMAT_* even caused bugs, as that is
an enum and not a proper format identifier.
BUG: 441253
It's confusing to have two signals (virtualScreenGeometryChanged() and
screenGeometryChanged()) that indicate the same thing.
This change ports parts of kwin from the screenGeometryChanged() signal
to the virtualScreenGeometryChanged() signal with the main motivation to
drop the former.
The virtualScreenGeometryChanged() signal was chosen as the replacement
for the consistency sake with EffectsHandler's virtualScreenGeometry and
virtualScreenSize properties.
Currently, the EffectsHandler has two signals that are emitted when the
combined geometry of all outputs change - virtualScreenGeometryChanged()
and screenGeometryChanged(). Having two signals is most likely a
historical artifact.
This change untangles the screenGeometryChanged() signal from the
Workspace and makes it the same as the virtualScreenGeometryChanged()
signal.
Currently, there are a couple of issues with output querying on X11:
(a) if an output is changed, for example its transform has been changed,
then all outputs will be destroyed and created again
(b) it's possible to encounter the case where the platform has no
outputs. The X11Platform destroys all outputs, then queries new
outputs. The Workspace and AbstractClient sub-classes handle having
no outputs very poorly! It's even possible to hit a crash.
With this change, outputs will be queried similar to how it's done on
Wayland.
The current duration is 300ms, which is inappropriate for two reasons:
1. It's too slow
2. It doesn't match one of the standard durations. The effect should
ideally use those durations directly, but if this is not possible
for technical reasons, it should use the effective value of one of
those durations. Units.longDuration is 200ms which is the most
appropriate one to use here.
Therefore, change the animation duration from 300ms to 200ms to match
the standard Units.longDuration duration.
BUG: 441308
FIXED-IN: 5.23
This makes it easier to spot if the effect is activated while there is
only one maximized window.
Note that anchors.margins cannot be used unfortunately as it won't take
effect until the ExpoLayout item is fully constructed. It may take a
couple of cycles for the geometry to settle down, which makes reasoning
about how the effect works difficult.
BUG: 312146
Once an animation starts due to property change, it cannot be easily
re-targeted. This can cause undesired animation jumps if a property
changes during startup (for example from 0 to its final value).
With this change, the window heap's animation will be disabled until
the effect starts the intro animation.
The ExpoLayout delays relayouting for optimization purposes. However,
this means that new geometry will be available only after returning to
the event loop.
This change delays starting the intro animation so it can be started
with new geometries.
It's confusing to have globalPos() and geometry() as both can return the
same information.
This change drops globalPos() function as it's not used outside the
AbstractWaylandOutput class and renames setGlobalPos() to moveTo() to
avoid having a setter without matching getter.
According to the Qt documentation, if an item overrides the
geometryChanged() method, it must call the base class method.
QQuickItem::geometryChanged() is responsible for emitting signals such
as xChanged(), yChanged(), etc.
It's the same as the currentDesktop except that it's a VirtualDesktop
object.
The main advantage of the currentVirtualDesktop property is that it
doesn't change if a virtual desktop is added or removed in the middle.
It also makes dealing with virtual desktop changes easier.
With the new virtual desktops model, a window can be on several virtual
desktops. Currently, scripts have no any way to get the list of desktops
the window is on. This change addresses that.
Currently, window thumbnails may be placed behind the panel, which
doesn't look good.
With this, the window heap will cover the same area as the maximize
area.
This makes the WindowHeap more robust to layout changes. Currently, the
main issue with it is that thumbnails will be misplaced if the heap's
scene position changes.
Kirigami.ScenePosition automagically keeps track of the item's scene pos.
If a window is on several virtual desktops, Workspace::switchWindow()
will not work as expected because AbstractClient::desktop() returns the
id of the last virtual desktop.
Since the active window is most likely on the current virtual desktop,
we can use that for filtering out irrelevant windows.
