AbstractRunner Class Reference

from PyKDE4.plasma import *

Inherits: QObject
Namespace: Plasma

Detailed Description

AbstractRunner plasma/abstractrunner.h <Plasma/AbstractRunner>

An abstract base class for Plasma Runner plugins.

Be aware that runners have to be thread-safe. This is due to the fact that each runner is executed in its own thread for each new term. Thus, a runner may be executed more than once at the same time. See match() for details.

Enumerations
Priority	{ LowestPriority, LowPriority, NormalPriority, HighPriority, HighestPriority }
Speed	{ SlowSpeed, NormalSpeed }
Methods
	__init__ (self, QObject parent=0, QString serviceId=QString())
	__init__ (self, QObject parent, QVariantList args)
QAction	action (self, QString id)
QHash	actions (self)
[QActio]	actionsForMatch (self, Plasma.QueryMatch match)
QAction	addAction (self, QString id, QIcon icon, QString text)
	addAction (self, QString id, QAction action)
	clearActions (self)
KConfigGroup	config (self)
	createRunOptions (self, QWidget widget)
QString	description (self)
bool	hasRunOptions (self)
QString	id (self)
Plasma.RunnerContext.Types	ignoredTypes (self)
	init (self)
	match (self, Plasma.RunnerContext context)
QString	name (self)
Plasma.Package	package (self)
	performMatch (self, Plasma.RunnerContext context)
Plasma.AbstractRunner.Priority	priority (self)
	reloadConfiguration (self)
	removeAction (self, QString id)
	run (self, Plasma.RunnerContext context, Plasma.QueryMatch match)
KService.List	serviceQuery (self, QString serviceType, QString constraint=QString())
	setHasRunOptions (self, bool hasRunOptions)
	setIgnoredTypes (self, Plasma.RunnerContext.Types types)
	setPriority (self, Plasma.AbstractRunner.Priority newPriority)
	setSpeed (self, Plasma.AbstractRunner.Speed newSpeed)
Plasma.AbstractRunner.Speed	speed (self)
Static Methods
QMutex	bigLock ()

Method Documentation

__init__	(	self,
		QObject	parent=0,
		QString	serviceId=QString()
	)

Constructs a Runner object. Since AbstractRunner has pure virtuals, this constructor can not be called directly. Rather a subclass must be created

__init__	(	self,
		QObject	parent,
		QVariantList	args
	)

QAction action	(	self,
		QString	id
	)

Returns the action associated with the id

QHash ( self )

Returns all registered actions

[QActio] actionsForMatch	(	self,
		Plasma.QueryMatch	match
	)

A given match can have more than action that can be performed on it. For example, a song match returned by a music player runner can be queued, added to the playlist, or played.

Call this method to add actions that can be performed by the runner. Actions must first be added to the runner's action registry. Note: execution of correct action is left up to the runner.

QAction addAction	(	self,
		QString	id,
		QIcon	icon,
		QString	text
	)

Creates and then adds an action to the action registry. AbstractRunner assumes ownership of the created action.

Parameters:

	id	A unique identifier string
	icon	The icon to display
	text	The text to display

Returns:: the created QAction

addAction	(	self,
		QString	id,
		QAction	action
	)

Adds an action to the runner's action registry.

The QAction must be created within the GUI thread; do not create it within the match method of AbstractRunner.

Parameters:

	id	A unique identifier string
	action	The QAction to be stored

QMutex bigLock ( )

Access to a shared lock that all runners (and code that manages/interacts with them) can share to protect access to non-thread-safe shared code or data. Access of KSycoca records, for instance, is one place this lock should be used.

Common usage:

{ QMutexLocker lock(bigLock()); .. do something that isn't thread safe .. }

clearActions ( self )

Clears the action registry. The action pool deletes the actions.

KConfigGroup config ( self )

Provides access to the runner's configuration object.

createRunOptions	(	self,
		QWidget	widget
	)

If hasRunOptions() returns true, this method may be called to get a widget displaying the options the user can interact with to modify the behaviour of what happens when a given match is selected.

Parameters:

widget

the parent of the options widgets.

QString description ( self )

Returns the description of this Runner

bool hasRunOptions ( self )

If the runner has options that the user can interact with to modify what happens when run or one of the actions created in fillMatches is called, the runner should return true

QString id ( self )

Returns an id string for the Runner

Plasma.RunnerContext.Types ignoredTypes ( self )

Returns the OR'ed value of all the Information types (as defined in RunnerContext.Type) this runner is not interested in.

Returns:: OR'ed value of black listed types

init ( self )

match	(	self,
		Plasma.RunnerContext	context
	)

This is the main query method. It should trigger creation of QueryMatch instances through RunnerContext.addMatch and RunnerContext.addMatches. It is called internally by performMatch().

If the runner can run precisely the requested term (RunnerContext.query()), it should create an exact match by setting the type to RunnerContext.ExactMatch. The first runner that creates a QueryMatch will be the default runner. Other runner's matches will be suggested in the interface. Non-exact matches should be offered via RunnerContext.PossibleMatch.

The match will be activated via run() if the user selects it.

Each runner is executed in its own thread. Whenever the user input changes this method is called again. Thus, it needs to be thread-safe. Also, all matches need to be reported once this method returns. Asyncroneous runners therefore need to make use of a local event loop to wait for all matches.

It is recommended to use local status data in async runners. The simplest way is to have a separate class doing all the work like so:

 void MyFancyAsyncRunner.match( RunnerContext& context )
 {
     QEventLoop loop;
     MyAsyncWorker worker( context );
     connect( &worker, SIGNAL(finished()),
              &loop, SLOT(quit()) );
     worker.work();
     loop.exec();
 }

Here MyAsyncWorker creates all the matches and calls RunnerContext.addMatch in some internal slot. It emits the finished() signal once done which will quit the loop and make the match() method return. The local status is kept entirely in MyAsyncWorker which makes match() trivially thread-safe.

If a particular match supports multiple actions, set up the corresponding actions in the actionsForMatch method. Do not call any of the action methods within this method!

Execution of the correct action should be handled in the run method. @caution This method needs to be thread-safe since KRunner will simply start a new thread for each new term.

Warning:: Returning from this method means to end execution of the runner.

@sa run(), RunnerContext.addMatch, RunnerContext.addMatches, QueryMatch

QString name ( self )

Returns the user visible engine name for the Runner

Plasma.Package package ( self )

Accessor for the associated Package object if any.

Note that the returned pointer is only valid for the lifetime of the runner.

Returns:: the Package object, or 0 if none

performMatch	(	self,
		Plasma.RunnerContext	context
	)

Triggers a call to match. This will call match() internally.

@arg context the search context used in executing this match.

Plasma.AbstractRunner.Priority priority ( self )

The priority of the runner.

See also:: setPriority

reloadConfiguration ( self )

Signal runner to reload its configuration.

removeAction	(	self,
		QString	id
	)

Removes the action from the action registry. AbstractRunner deletes the action once removed.

Parameters:

The id of the action to be removed

run	(	self,
		Plasma.RunnerContext	context,
		Plasma.QueryMatch	match
	)

Called whenever an exact or possible match associated with this runner is triggered.

Parameters:

	context	The context in which the match is triggered, i.e. for which the match was created.
	match	The actual match to run/execute.

KService.List serviceQuery	(	self,
		QString	serviceType,
		QString	constraint=QString()
	)

A blocking method to do queries of installed Services which can provide a measure of safety for runners running their own threads. This should be used instead of calling KServiceTypeTrader.query(..) directly.

@arg serviceType a service type like "Plasma/Applet" or "KFilePlugin" @arg constraint a constraint to limit the choices returned.

See also:: KServiceTypeTrader.query(const QString&, const QString&)

Returns:: a list of services that satisfy the query.

setHasRunOptions	(	self,
		bool	hasRunOptions
	)

Sets whether or not the runner has options for matches

setIgnoredTypes	(	self,
		Plasma.RunnerContext.Types	types
	)

Sets the types this runner will ignore

Parameters:

types

OR'ed listed of ignored types

setPriority	(	self,
		Plasma.AbstractRunner.Priority	newPriority
	)

Sets the priority of the runner. Lower priority runners are executed only after higher priority runners.

setSpeed	(	self,
		Plasma.AbstractRunner.Speed	newSpeed
	)

Sets the nominal speed of the runner. Only slow runners need to call this within their constructor because the default speed is NormalSpeed. Runners that use DBUS should call this within their constructors.

Plasma.AbstractRunner.Speed speed ( self )

The nominal speed of the runner.

See also:: setSpeed

Enumeration Documentation

Priority

Specifies a priority for the runner

Enumerator:

LowestPriority = 0
LowPriority
NormalPriority
HighPriority
HighestPriority

Speed

Specifies a nominal speed for the runner

Enumerator:

SlowSpeed
NormalSpeed

AbstractRunner Class Reference

Detailed Description

Enumerations

Methods

Static Methods

Method Documentation

Enumeration Documentation

Modules