If the configured decoration plugin fails to load, we try to load
the default decoration plugin. If that also fails to load, we try
to load Aurorae, which is shipped with KWin, so the chances are
higher that it is available.
Also the checks in Aurorae are improved to fall back to the Plastik
theme if the selected SVG theme is not available.
BUG: 341014
FIXED-IN: 5.2.0
REVIEW: 121859
Paint is in the middle of the compositor rendering loop. Updating
the shadow at that point breaks KWin. Thus we delay the update to
the next event cycle. Obviously it would be even better to only
update the shadow if it changed, but that might be too expensive.
This brings back the configuration for decoration plugins. As a change
to the old variant the configure button is moved into the list view
together with the preview. It is enabled/disabled depending on data
provided by the DecorationModel. For a plugin the DecorationModel
queries for a boolean "kcmodule" key in the metadata. For a theme it
invokes the slot hasConfiguration with the theme name which returns
whether the theme provides configuration.
The actual opening of the configuration is triggered from the
PreviewBridge, which uses the existing KPluginFactory to load the
KCModule. The decoration plugin must provide the keyword "kcmodule"
for it.
So far Aurorae is adjusted and provides configuration for the Plastik
decoration. The interaction with the configuration module works, but
the configuration itself for Plastik seems to be currently broken.
KNewStuff is no longer hard-coded to Aurorae themes. Instead the
availability of KNewStuff is derived from the available plugin
metadata. If the section org.kde.kdecoration2 contains a key
"KNewStuff" it's value is interpreted as the knsrc config file name.
If there is at least one plugin with such a key KNS gets enabled.
If there are multiple plugins providing KNS support the download
button is turned into a button with a connected menu and each menu
entry points to one of the available resources. Of course this is
not optimal, but KNS doesn't allow the combining of multiple config
files.
QQuickRenderControl brings a few advantages for the usage in Aurorae:
* can create an offscreen window
* eliminate the need for mutex as we control the rendering
* control the tear down of the QML scene (no more crashes in Qt)
In future we can further improve this, by sharing the context, so
that we can use the FBO texture directly. But this first needs
some more work in KWin core.
As we don't hard depend on Qt 5.4 yet it's using ifdefs. Once we have
Qt 5.4 the old code will be removed.
Adjust all components to use the QSharedPointer. Aurorae obviously has
to create a QSharedPointer, Shadow holds a QSharedPointer for the
DecorationShadow (advantage: is kept when the Decoration is destroyed),
and the KCM needs to add a property on PreviewItem to get access to the
Shadow. It's no longer a Q_PROPERTY on Decoration and we cannot re-add
it as a dynamic property (cannot be read from QML side).
* Aurorae needs to pass QVariantList args to parent Decoration
* DecorationBridge implementation needs to be a KWIN_SINGLETON
* DecorationBridge needs to be passed with args to created Decoration
The idea behind the ThemeFinder is to expose a way for a configuration
module to find all themes. The API is not yet finalized, thus it's just
a QObject with a Q_PROPERTY themes of type QVariantMap with key being
the user visible name and value being the internal theme name.
The ThemeFinder will have to be moved to KDecoration library.
The json metadata provides a "themeListKeyword" which is used as the
keyword to the KPluginFactory.
DecorationShadow is supported through using the padding values. The
window becomes larger by the padding and gets positioned accordingly.
This requires to translate all mouse events.
The DecorationShadow is just using the complete image, which is kind of
a memory waste, but at least the SVG based Aurorae doesn't provide us
better information (might be added, but would probably need changes in
the theme).
For switching back to non-compositing we recreate the QuickWindow. It's
not fortunate, but as long as we do not yet have the render control it's
needed.
The port to KDecoration2 means quite some changes in the way how Aurorae
works. First of all: the theme to load is passed to the Deocoration ctor
and not searched for by Aurorae itself.
The rendering mechanismn didn't change significantly yet. It's still
rendering to an FBO and passing the image on. This needs some further
work as KDecoration2 does not support the padding any more. So all
themes using shadow are currently broken.
Another big change is the way how the rendering scene is constructed
and used. KDecoration2 doesn't want the the Decoration to be a native
window. But for being able to render a QtQuick scene at all we need a
QQuickWindow. Thus it creates a window parented to the decoration id,
but not accepting any input event. Input is nowadays controlled from
the outside: events are passed into the Decoration, so we don't want
the QtQuick window intercepting events.
In case of non-composited the normal FBO mechanism doesn't work and
Aurorae just renders to the QQuickWindow directly. This could use
some optimization in the decoration renderer in KWin core to not even
try to perform the normal rendering. On the other hand it's probably
too much a hassle for the use case.
The rendering architecture might hopefully be improved with Qt 5.4
and the new QQuickRenderControl class.
The QQuickWindow also exposes a problem for preview in the
kdecoration-viewer and the future KCM: we don't want a different
window, but best would be to get to the QML scene directly. A small
hack is added to have the previewers set a "visualParent" which Aurorae
uses to parent the QML scene to without the need to create a
QQuickWindow.
The Text.horizontalAlignment property expects AlignHCenter instead of
AlignCenter. By not using AlignHCenter the centering broke when a window
got maximized.
It's possible that the rendering thread is still writing to the
buffer and if we destroy the buffer before it's finished KWin is going
to crash. So let's mutex lock the dtor to ensure that the rendering
thread finishes before we tear down the client.
BUG: 336950
