Plasma/libplasma2

Summary

This page is dedicated to planning of the libplasma2.

libplasma2 will be binary and source incompatible with the current libplasma. This means that we can fix some issues that are currently present in plasma's design. Any changes that affect the source compatibility must be documented here

Enter the issues you wish fixed in the following form:

Idea:	Change libplasma2
Summary:	We have a chance to change stuff now
Proposed solution:	We change things
Discussion:	http://mail.kde.org/pipermail/plasma-devel/2010-October

General TODOs

Status	Name	Summary	Developer
DONE	Fix plasmoidpackagetest	plasmoidpackagetest currently does not build due to missing KIO, etc. API. Port away from KIO and friends to Qt equivalents and get it pass again.	<[email protected]>
TODO	Signing	Integrate Signing classes with Package; put Signing class in a thread, potentially make it private API. Current is in staging directory.	<[email protected]>

Design Issues

Status	Name	Summary	Developer
DONE	ServiceJob is autostarted	ServiceJob is connected to a zero timer in Service::startOperationCall. If exec() is called on the job and it doesn't finish immediately, then the event loop will be start and the timer will fire causing start() to be called a second time.	<[email protected]>
TODO	Fewer friend classes	Look at all friend relationships and see how many can be removed now due to evolution of libplasma itself or clever new approaches to the old problem. Public API clarity and cleanliness must not be sacrificed, however. Internal ugliness is better than external ugliness.	<[email protected]>
DONE	DataEngineConsumer public API	Right now it is a bit too easy to make mistakes with using DataEngines outside of the normal consumers (Applet, Wallpaper, etc.). This is because DataEngineManager exposes the reference counting details as public API.	<[email protected]>
DONE	Refactor Package* Classes	PackageMetaData is a relatively thin and inefficient wrapper around KDesktopFile. It's used rarely and doesn't serve a clear purpose. PackageStructure is a relatively static class that combines both a method for getting new packages as well as a description of the underlying package.	<[email protected]>
DONE	PackageStructure::installPackage should be async	Package::installPackage is current synchronous, which prevents running it in another thread, doing user interaction (e.g. to confirm other dependencies to download) or taking additional actions such as downloads.	<[email protected]>
TODO	Make DataEngine implicitly shared	We pass DataEngines around as pointers, which makes them vulnerable to all the usual pointer-related issues: crashes, accidental deletions, etc.	<[email protected]>
TODO	Out of process DataEngines	Out of process DataEngines	<[email protected]>
TODO	More model-like dataengines	Many dataengines return data as series of items: like rss, microblog and tasks, and they do in different ways, rss has a list of Data in a single key, microblog has an item per key, tasks has an item per source.	<[email protected]>
TODO	Lazy dataengine evaluation	The problem with the current DE implementation (QVariants) is that data is kept in memory even if the user didn't request it. (for example, some engine could keep a pixmap ready for a data item, although the applet only wants the title.	<[email protected]>

API Issues

Status	Name	Summary	Developer
DONE	Remove unimplemented virtual methods	In various places there are virtual methods which were re-implemented, but then later had the implementation removed, but for binary compatibility reasons the method itself has to remain.	<[email protected]>
DONE	[mM]imetype -> [mM]imeType	Everywhere else in KDE/Qt API it is "MimeType"	<[email protected]>
DONE	Wallpaper drop handling	We now have two ways to note that a URL has been added to a wallpaper via external means: urlDropped(KUrl) and setUrls(KUrl::List).	<[email protected]>
DONE	Applet::appletDestroyed signal poorly named	appletDestroyed is emitted in ~Applet, but this can happen even if it isn't "destroyed" but just deleted. Despite its name, appletDestroyed has nothing to do with Applet::destroy() and Applet::destroyed()	<[email protected]>
DONE	Svg::setImagePath is not virtual	FrameSvg (and potentially other subclasses of Svg) need to take action when the image path is changed. setImagePath is not virtual nor does it call any internal virtuals. This has resulted in a necessary but unfortunate hack in Svg::setImagePath specifically for FrameSvg.	<[email protected]>
DONE	Merge ExtenderItem::setGroup methods	There are multiple setGroup methods in ExtenderItem, which could be merged into one method with suitable default parameters.	<[email protected]>
DONE	Merge Theme::findInCache methods	There are multiple findInCache methods in Theme, which could be merged into one method with suitable default parameters.	<[email protected]>
DONE	Dialog::graphicsWidget() is not const	As a simple getter, graphicsWidget() should be const.	<[email protected]>
DONE	Wallpaper has a protected data member	QList<QAction*> contextActions is not in the dptr.	<[email protected]>
DONE	Use virtuals instead of slots in AbstractToolBox	There are three slots in AbstractToolBox that really ought to be virtuals: restore, save and reposition. They are currently QMetaObject::invoke()'d instead.	<[email protected]>
DONE	isBusy Q_PROPERTY duplicate in Applet	There are two "busy" Q_PROPERTY entries defined in Applet: isBusy and busy. The latter is the correct frm.	<[email protected]>
DONE	Applet::geometryChanged() superfluous now	QGraphicsWidget has a geometryChanged() signal now, it is only kept in Applet to preserve binary compatibility.	<[email protected]>
DONE	Applet::messageButtonPressed should pass the fully qualified type	Applet has a signal void messageButtonPressed(const MessageButton button). Since moc does a string comparison in connect, trying to connect it to a slot that takes "Plasma::MessageButton" will not work because "MessageButton" nq "Plasma::MessageButton"	<[email protected]>
DONE	AbstractRunner::mimeDataForMatch	mimeDataForMatch is a slot due to BC.	<[email protected]>
DONE	Add const setWallpaperPath	Add a function to Plasma::Wallpaper as virtual setWallpaperPath(const KUrl &url)	<[email protected]>
DONE	un/installPackage should be private	Both methods are static members of the public API, though all install/uninstall calls should be done through PackageStructure	<[email protected]>
DONE	Remove context info classes	The classes are unused, and are not working. All data they provide can be accessible via data engines	<[email protected]>

QGraphicsView vs QML2

Status	Name	Summary	Developer
DONE	Migrate widgets to QtComponents, drop current libplasma widgets	QML allows faster UI creation compared to old widgets, Scene-graph doesn't support QGraphicsWidget	<[email protected]>
DONE	Port Corona away from QGV	Change Corona from a QGraphicsScene to being a (singleton) scene bookeeper, In Scene-graph there is an 1:1 association scene:view	<[email protected]>
DONE	Applet no more a GraphicsItem	Right now Applet is a QGraphicsWidget that can optionally include a QML root element (with its declarative engine), mixing QGraphicsWidgets and QDeclarativeItems, nd maybe creatng unneded items.	<[email protected]>
IN PROGRESS	A shell that is based on scene graph	Write a single shell based on scene graph.	<[email protected]>
IN PROGRESS	Port QML scriptengine to qml2	The QML scriptengine should create the QQuickItems corresponding to containments and applets, parsing the qml in their packages	<[email protected]>
IN PROGRESS	Port QML scriptengine away from QScriptEngine	QML2 doesn't have QScriptEngine. It must either use only the declarative engine (means everything is qobject) or use directly V8	<[email protected]>
DONE	libplasma not depending on graphics backends	The above issue suggests that libplasma could not depend anymore neither from QGraphicsView or SceneGraph.	<[email protected]>

QtQuick2 porting

The Plasma Quick APIs have been ported to QtQuick2. This has been done with API compatibility in mind. Usually, it is pretty easy to get your QtQuick2 code running on top of QtQuick2 and Plasma2. This document guides you through the important changes in QtQuick2.

As of today (April 8th, 2013), most of the imports provided by the following modules have been ported:

• org.kde.plasma.core (PlasmaCore)
• org.kde.plasma.components (PlasmaComponents)
• org.kde.plasma.extras (PlasmaExtras)
• org.kde.qtextracomponents (QtExtras)

The API has been kept compatible to minimize the porting effort to Plasma2. With the following changes, you can get your code running on Plasma2:

• Change import version numbers of all above components to 2.0
• PlasmaCore.ToolTip: image property now takes a QString, which is passed as source into an Image item