plasma-framework/abstractrunner.h

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/*
* Copyright 2006-2007 Aaron Seigo <aseigo@kde.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details
*
* You should have received a copy of the GNU Library General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#ifndef PLASMA_ABSTRACTRUNNER_H
#define PLASMA_ABSTRACTRUNNER_H
#include <QtCore/QObject>
#include <QtCore/QMutex>
#include <QtCore/QStringList>
#include <kconfiggroup.h>
#include <kservice.h>
#include <plasma/plasma_export.h>
#include <plasma/runnercontext.h>
#include <plasma/querymatch.h>
#include <plasma/version.h>
class QAction;
class KCompletion;
namespace Plasma
{
class Package;
class RunnerScript;
class QueryMatch;
class AbstractRunnerPrivate;
/**
* @class AbstractRunner plasma/abstractrunner.h <Plasma/AbstractRunner>
*
* @short 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.
*/
class PLASMA_EXPORT AbstractRunner : public QObject
{
Q_OBJECT
public:
/** Specifies a nominal speed for the runner */
enum Speed {
SlowSpeed,
NormalSpeed
};
/** Specifies a priority for the runner */
enum Priority {
LowestPriority = 0,
LowPriority,
NormalPriority,
HighPriority,
HighestPriority
};
/** An ordered list of runners */
typedef QList<AbstractRunner*> List;
virtual ~AbstractRunner();
/**
* 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:
*
* \code
* void MyFancyAsyncRunner::match( RunnerContext& context )
* {
* QEventLoop loop;
* MyAsyncWorker worker( context );
* connect( &worker, SIGNAL(finished()),
* &loop, SLOT(quit()) );
* worker.work();
* loop.exec();
* }
* \endcode
*
* 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
*/
virtual void match(Plasma::RunnerContext &context);
/**
* Triggers a call to match. This will call match() internally.
*
* @arg context the search context used in executing this match.
*/
void performMatch(Plasma::RunnerContext &context);
/**
* 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
*/
bool hasRunOptions();
/**
* 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.
*
* @param widget the parent of the options widgets.
*/
virtual void createRunOptions(QWidget *widget);
/**
* Called whenever an exact or possible match associated with this
* runner is triggered.
*
* @param context The context in which the match is triggered, i.e. for which
* the match was created.
* @param match The actual match to run/execute.
*/
virtual void run(const Plasma::RunnerContext &context, const Plasma::QueryMatch &match);
/**
* The nominal speed of the runner.
* @see setSpeed
*/
Speed speed() const;
/**
* The priority of the runner.
* @see setPriority
*/
Priority priority() const;
/**
* Returns the OR'ed value of all the Information types (as defined in RunnerContext::Type)
* this runner is not interested in.
* @return OR'ed value of black listed types
*/
RunnerContext::Types ignoredTypes() const;
/**
* Sets the types this runner will ignore
* @param types OR'ed listed of ignored types
*/
void setIgnoredTypes(RunnerContext::Types types);
/**
* Returns the user visible engine name for the Runner
*/
QString name() const;
/**
* Returns an id string for the Runner
*/
QString id() const;
/**
* Returns the description of this Runner
*/
QString description() const;
/**
* Accessor for the associated Package object if any.
*
* Note that the returned pointer is only valid for the lifetime of
* the runner.
*
* @return the Package object, or 0 if none
**/
const Package *package() const;
/**
* Signal runner to reload its configuration.
*/
virtual void reloadConfiguration();
/**
* 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 ..
* }
*/
static QMutex *bigLock();
protected:
friend class RunnerManager;
friend class RunnerManagerPrivate;
/**
* Constructs a Runner object. Since AbstractRunner has pure virtuals,
* this constructor can not be called directly. Rather a subclass must
* be created
*/
explicit AbstractRunner(QObject *parent = 0, const QString &serviceId = QString());
AbstractRunner(QObject *parent, const QVariantList &args);
/**
* Provides access to the runner's configuration object.
*/
KConfigGroup config() const;
/**
* Sets whether or not the runner has options for matches
*/
void setHasRunOptions(bool hasRunOptions);
/**
* 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.
*/
void setSpeed(Speed newSpeed);
/**
* Sets the priority of the runner. Lower priority runners are executed
* only after higher priority runners.
*/
void setPriority(Priority newPriority);
/**
* 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 KServiceTypeTrader::query(const QString&, const QString&)
*
* @return a list of services that satisfy the query.
*/
KService::List serviceQuery(const QString &serviceType,
const QString &constraint = QString()) const;
/**
* 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.
*/
virtual QList<QAction*> actionsForMatch(const Plasma::QueryMatch &match);
/**
* Creates and then adds an action to the action registry.
* AbstractRunner assumes ownership of the created action.
*
* @param id A unique identifier string
* @param icon The icon to display
* @param text The text to display
* @return the created QAction
*/
QAction* addAction(const QString &id, const QIcon &icon, const QString &text);
/**
* 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.
*
* @param id A unique identifier string
* @param action The QAction to be stored
*/
void addAction(const QString &id, QAction *action);
/**
* Removes the action from the action registry.
* AbstractRunner deletes the action once removed.
*
* @param id The id of the action to be removed
*/
void removeAction(const QString &id);
/**
* Returns the action associated with the id
*/
QAction* action(const QString &id) const;
/**
* Returns all registered actions
*/
QHash<QString, QAction*> actions() const;
/**
* Clears the action registry.
* The action pool deletes the actions.
*/
void clearActions();
protected Q_SLOTS:
void init();
private:
AbstractRunnerPrivate *const d;
};
} // Plasma namespace
#define K_EXPORT_PLASMA_RUNNER( libname, classname ) \
K_PLUGIN_FACTORY(factory, registerPlugin<classname>();) \
K_EXPORT_PLUGIN(factory("plasma_runner_" #libname)) \
K_EXPORT_PLUGIN_VERSION(PLASMA_VERSION)
#define K_EXPORT_RUNNER_CONFIG( name, classname ) \
K_PLUGIN_FACTORY(ConfigFactory, registerPlugin<classname>();) \
K_EXPORT_PLUGIN(ConfigFactory("kcm_krunner_" #name)) \
K_EXPORT_PLUGIN_VERSION(PLASMA_VERSION)
#endif