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Diffstat (limited to 'src/dbus/qdbusservicewatcher.cpp')
| -rw-r--r-- | src/dbus/qdbusservicewatcher.cpp | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/src/dbus/qdbusservicewatcher.cpp b/src/dbus/qdbusservicewatcher.cpp new file mode 100644 index 0000000..4872732 --- /dev/null +++ b/src/dbus/qdbusservicewatcher.cpp @@ -0,0 +1,374 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtDBus module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qdbusservicewatcher.h" +#include "qdbusconnection.h" +#include "qdbus_symbols_p.h" + +#include <QStringList> + +#include <private/qobject_p.h> + +Q_GLOBAL_STATIC_WITH_ARGS(QString, busService, (QLatin1String(DBUS_SERVICE_DBUS))) +Q_GLOBAL_STATIC_WITH_ARGS(QString, busPath, (QLatin1String(DBUS_PATH_DBUS))) +Q_GLOBAL_STATIC_WITH_ARGS(QString, busInterface, (QLatin1String(DBUS_INTERFACE_DBUS))) +Q_GLOBAL_STATIC_WITH_ARGS(QString, signalName, (QLatin1String("NameOwnerChanged"))) + +class QDBusServiceWatcherPrivate: public QObjectPrivate +{ + Q_DECLARE_PUBLIC(QDBusServiceWatcher) +public: + QDBusServiceWatcherPrivate(const QDBusConnection &c, QDBusServiceWatcher::WatchMode wm) + : connection(c), watchMode(wm) + { + } + + QStringList servicesWatched; + QDBusConnection connection; + QDBusServiceWatcher::WatchMode watchMode; + + void _q_serviceOwnerChanged(const QString &, const QString &, const QString &); + void setConnection(const QStringList &services, const QDBusConnection &c, QDBusServiceWatcher::WatchMode watchMode); + + QStringList matchArgsForService(const QString &service); + void addService(const QString &service); + void removeService(const QString &service); +}; + +void QDBusServiceWatcherPrivate::_q_serviceOwnerChanged(const QString &service, const QString &oldOwner, const QString &newOwner) +{ + Q_Q(QDBusServiceWatcher); + emit q->serviceOwnerChanged(service, oldOwner, newOwner); + if (oldOwner.isEmpty()) + emit q->serviceRegistered(service); + else if (newOwner.isEmpty()) + emit q->serviceUnregistered(service); +} + +void QDBusServiceWatcherPrivate::setConnection(const QStringList &s, const QDBusConnection &c, QDBusServiceWatcher::WatchMode wm) +{ + if (connection.isConnected()) { + // remove older rules + foreach (const QString &s, servicesWatched) + removeService(s); + } + + connection = c; + watchMode = wm; + servicesWatched = s; + + if (connection.isConnected()) { + // add new rules + foreach (const QString &s, servicesWatched) + addService(s); + } +} + +QStringList QDBusServiceWatcherPrivate::matchArgsForService(const QString &service) +{ + QStringList matchArgs; + matchArgs << service; + + switch (watchMode) { + case QDBusServiceWatcher::WatchForOwnerChange: + break; + + case QDBusServiceWatcher::WatchForRegistration: + matchArgs << QString::fromLatin1("", 0); + break; + + case QDBusServiceWatcher::WatchForUnregistration: + matchArgs << QString() << QString::fromLatin1("", 0); + break; + } + return matchArgs; +} + +void QDBusServiceWatcherPrivate::addService(const QString &service) +{ + QStringList matchArgs = matchArgsForService(service); + connection.connect(*busService(), *busPath(), *busInterface(), *signalName(), + matchArgs, QString(), q_func(), + SLOT(_q_serviceOwnerChanged(QString,QString,QString))); +} + +void QDBusServiceWatcherPrivate::removeService(const QString &service) +{ + QStringList matchArgs = matchArgsForService(service); + connection.disconnect(*busService(), *busPath(), *busInterface(), *signalName(), + matchArgs, QString(), q_func(), + SLOT(_q_serviceOwnerChanged(QString,QString,QString))); +} + +/*! + \class QDBusServiceWatcher + \since 4.6 + \inmodule QtDBus + + \brief The QDBusServiceWatcher class allows the user to watch for a bus service change. + + A QDBusServiceWatcher object can be used to notify the application about + an ownership change of a service name on the bus. It has three watch + modes: + + \list + \o watching for service registration only + \o watching for service unregistration only + \o watching for any kind of service ownership change (the default mode) + \endlist + + Besides being created or deleted, services may change owners without a + unregister/register operation happening. So the \ref serviceRegistered() + and \ref serviceUnregistered() signals may not be emitted if that + happens. + + This class is more efficient than using the + QDBusConnectionInterface::serviceOwnerChanged() signal because it allows + one to receive only the signals for which the class is interested in. + + \sa QDBusConnection +*/ + +/*! + \enum QDBusServiceWatcher::WatchModeFlag + + QDBusServiceWatcher supports three different watch modes, which are configured by this flag: + + \value WatchForRegistration watch for service registration only, ignoring + any signals related to other service ownership change. + + \value WatchForUnregistration watch for service unregistration only, + ignoring any signals related to other service ownership change. + + \value WatchForOwnerChange watch for any kind of service ownership + change. +*/ + +/*! + \property QDBusServiceWatcher::watchMode + + The \c watchMode property holds the current watch mode for this + QDBusServiceWatcher object. The default value for this property is + QDBusServiceWatcher::WatchForOwnershipChange. +*/ + +/*! + \property QDBusServiceWatcher::watchedServices + + The \c servicesWatched property holds the list of services watched. + + Note that modifying this list with setServicesWatched() is an expensive + operation. If you can, prefer to change it by way of addWatchedService() + and removeWatchedService(). +*/ + +/*! + \fn void QDBusServiceWatcher::serviceRegistered(const QString &serviceName) + + This signal is emitted whenever this object detects that the service \a + serviceName became available on the bus. + + \sa serviceUnregistered(), serviceOwnerChanged() +*/ + +/*! + \fn void QDBusServiceWatcher::serviceUnregistered(const QString &serviceName) + + This signal is emitted whenever this object detects that the service \a + serviceName was unregistered from the bus and is no longer available. + + \sa serviceRegistered(), serviceOwnerChanged() +*/ + +/*! + \fn void QDBusServiceWatcher::serviceOwnerChanged(const QString &serviceName, const QString &oldOwner, const QString &newOwner) + + This signal is emitted whenever this object detects that there was a + service ownership change relating to the \a serviceName service. The \a + oldOwner parameter contains the old owner name and \a newOwner is the new + owner. Both \a oldOwner and \a newOwner are unique connection names. + + Note that this signal is also emitted whenever the \a serviceName service + was registered or unregistered. If it was registered, \a oldOwner will + contain an empty string, whereas if it was unregistered, \a newOwner will + contain an empty string. + + If you need only to find out if the service is registered or unregistered + only, without being notified that the ownership changed, consider using + the specific modes for those operations. This class is more efficient if + you use the more specific modes. + + \sa serviceRegistered(), serviceUnregistered() +*/ + +/*! + Creates a QDBusServiceWatcher object. Note that until you set a + connection with setConnection(), this object will not emit any signals. + + The \a parent parameter is passed to QObject to set the parent of this + object. +*/ +QDBusServiceWatcher::QDBusServiceWatcher(QObject *parent) + : QObject(*new QDBusServiceWatcherPrivate(QDBusConnection(QString()), WatchForOwnerChange), parent) +{ +} + +/*! + Creates a QDBusServiceWatcher object and attaches it to the \a connection + connection. Also, this function immediately starts watching for \a + watchMode changes to service \a service. + + The \a parent parameter is passed to QObject to set the parent of this + object. +*/ +QDBusServiceWatcher::QDBusServiceWatcher(const QString &service, const QDBusConnection &connection, WatchMode watchMode, QObject *parent) + : QObject(*new QDBusServiceWatcherPrivate(connection, watchMode), parent) +{ + d_func()->setConnection(QStringList() << service, connection, watchMode); +} + +/*! + Destroys the QDBusServiceWatcher object and releases any resources + associated with it. +*/ +QDBusServiceWatcher::~QDBusServiceWatcher() +{ +} + +/*! + Returns the list of D-Bus services that are being watched. + + \sa setWatchedServices() +*/ +QStringList QDBusServiceWatcher::watchedServices() const +{ + return d_func()->servicesWatched; +} + +/*! + Sets the list of D-Bus services being watched to be \a services. + + Note that setting the entire list means removing all previous rules for + watching services and adding new ones. This is an expensive operation and + should be avoided, if possible. Instead, use addWatchedService() and + removeWatchedService() if you can to manipulate entries in the list. +*/ +void QDBusServiceWatcher::setWatchedServices(const QStringList &services) +{ + Q_D(QDBusServiceWatcher); + if (services == d->servicesWatched) + return; + d->setConnection(services, d->connection, d->watchMode); +} + +/*! + Adds \a newService to the list of services to be watched by this object. + This function is more efficient than setWatchedServices() and should be + used whenever possible to add services. +*/ +void QDBusServiceWatcher::addWatchedService(const QString &newService) +{ + Q_D(QDBusServiceWatcher); + if (d->servicesWatched.contains(newService)) + return; + d->addService(newService); + d->servicesWatched << newService; +} + +/*! + Removes the \a service from the list of services being watched by this + object. Note that D-Bus notifications are asynchronous, so there may + still be signals pending delivery about \a service. Those signals will + still be emitted whenever the D-Bus messages are processed. + + This function returns true if any services were removed. +*/ +bool QDBusServiceWatcher::removeWatchedService(const QString &service) +{ + Q_D(QDBusServiceWatcher); + d->removeService(service); + return d->servicesWatched.removeOne(service); +} + +QDBusServiceWatcher::WatchMode QDBusServiceWatcher::watchMode() const +{ + return d_func()->watchMode; +} + +void QDBusServiceWatcher::setWatchMode(WatchMode mode) +{ + Q_D(QDBusServiceWatcher); + if (mode == d->watchMode) + return; + d->setConnection(d->servicesWatched, d->connection, mode); +} + +/*! + Returns the QDBusConnection that this object is attached to. + + \sa setConnection() +*/ +QDBusConnection QDBusServiceWatcher::connection() const +{ + return d_func()->connection; +} + +/*! + Sets the D-Bus connection that this object is attached to be \a + connection. All services watched will be transferred to this connection. + + Note that QDBusConnection objects are reference counted: + QDBusServiceWatcher will keep a reference for this connection while it + exists. The connection is not closed until the reference count drops to + zero, so this will ensure that any notifications are received while this + QDBusServiceWatcher object exists. + + \sa connection() +*/ +void QDBusServiceWatcher::setConnection(const QDBusConnection &connection) +{ + Q_D(QDBusServiceWatcher); + if (connection.name() == d->connection.name()) + return; + d->setConnection(d->servicesWatched, connection, d->watchMode); +} + +#include "moc_qdbusservicewatcher.cpp" |