For this AbstractBackend has a new virtual screenGeometries() method
which returns a QVector<QRect>. By default it's just one QRect at 0/0
with the size of the one screenSize().
X11, Wayland, virtual, Framebuffer and hwcomposer have extremely
similar screens implementations. Let's add a base implementation
for them as a BasicScreens.
Each of the backends becomes a plugin. This allows kwin_wayland to load
the requested plugin and kwin itself doesn't need to link all the
libraries needed. E.g. libdrm is no longer linked if running kwin_x11.
Also this allows to create backends for the non-standard EGL platforms
(examples could be raspberrypi or Android devices).
A new implementation of the Screens interface is added which uses XRandR
directly instead of relying on QDesktopWidget. The implementation is
provided in a new implementation file screens_xrandr.cpp.
XRandRScreens comes with a unit test. Unfortunately it's rather difficult
to provide a proper unit test against XRandR. Xvfb (which is obviously
used on the CI system) doesn't provide the XRandR extension. Also on a
"normal" developer system one would not want to just execute the test as
the results are not predictable (number of available outputs?) and the
test would mess up the setup resulting in nobody wanting to execute the
test.
As a solution to both problems the unit test starts Xephyr as a nested
X server. This allows to have at least some limited tests against XRandR.
Nevertheless there are a few things which I was not able to test:
* multiple outputs
* no output at all
The nested X Server approach makes the interaction rather complex. Qt
opens it's connection against the main X Server thus QX11Info provides
a wrong connection and also KWin::connection() which is heavily used by
xcbutils and thus all the RandR wrappers have the wrong connection. To
circumvent this problem the test is GUILESS. In case it would call into
any code using QX11Info, it would probably either runtime fail or crash.
REVIEW: 117614
Uses the information provided by the Wayland outputs to setup the data
about the available screens.
In order to properly work together with the X Server the implementation
syncs the data to the X system using XRandR. If XRandR is not available
this is most likely going to not work correctly.
Screens provides a size which is constructed from the size of
the bounding geometry of all screens and provides an overload taking
an int to return the size of a specified screen. For geometry() a new
ovload is added without an argument, which is just a convenient wrapper
for QRect(QPoint(0, 0), size()).
Both new methods are exported to effects and scripting as new
properties there called virtualScreenSize and virtualScreenGeometry.
The (virtual) size gets cached in screens and is updated whenever the
count or geometry changes.
Construction of Screens is slightly changed by moving the init code
from ctor into a virtual method init(). Reason is that we ended in
a loop with accessing the singleton pointer before it was set.
REVIEW: 116114
largely reverts b164e9912c9b5f9c9ae619bbd79355d317174115
which prevented the crash but due to early screen updating
causes issues with scene/overlay update on at least intel chips
BUG: 322970
FIXED-IN: 4.11
CCBUG: 322156
REVIEW: https://git.reviewboard.kde.org/r/111811/
Following the approaches of other split out functionality Screens is a
singleton class created by Workspace.
The class takes over the responsibility for:
* screenChanged signal delayed by timer
* number of screens
* geometry of given screen
* active screen
* config option for active screen follows mouse
The class contains a small abstraction layer and has a concrete subclass
wrapping around QDesktopWidget, but the idea is to go more low level and
interact with XRandR directly to get more detailed information.
All over KWin the usage from QDesktopWidget is ported over to the new
Screens class.
REVIEW: 109839
