File indexing completed on 2024-05-12 05:37:09

 /*
     SPDX-FileCopyrightText: 2015 Marco Martin <mart@kde.org>
     SPDX-FileCopyrightText: 2020 Konrad Materka <materka@gmail.com>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #include "dbusserviceobserver.h"
 #include "debug.h"
 
 #include "systemtraysettings.h"
 
 #include <KPluginMetaData>
 
 #include <QDBusConnection>
 #include <QDBusConnectionInterface>
 #include <QDBusServiceWatcher>
 
 DBusServiceObserver::DBusServiceObserver(const QPointer<SystemTraySettings> &settings, QObject *parent)
     : QObject(parent)
     , m_settings(settings)
     , m_sessionServiceWatcher(new QDBusServiceWatcher(this))
     , m_systemServiceWatcher(new QDBusServiceWatcher(this))
 {
     m_sessionServiceWatcher->setConnection(QDBusConnection::sessionBus());
     m_systemServiceWatcher->setConnection(QDBusConnection::systemBus());
 
     connect(m_settings, &SystemTraySettings::enabledPluginsChanged, this, &DBusServiceObserver::initDBusActivatables);
 
     // Watch for new services
     connect(m_sessionServiceWatcher, &QDBusServiceWatcher::serviceRegistered, this, [this](const QString &serviceName) {
         if (!m_dbusSessionServiceNamesFetched) {
             return;
         }
         serviceRegistered(serviceName);
     });
     connect(m_sessionServiceWatcher, &QDBusServiceWatcher::serviceUnregistered, this, [this](const QString &serviceName) {
         if (!m_dbusSessionServiceNamesFetched) {
             return;
         }
         serviceUnregistered(serviceName);
     });
     connect(m_systemServiceWatcher, &QDBusServiceWatcher::serviceRegistered, this, [this](const QString &serviceName) {
         if (!m_dbusSystemServiceNamesFetched) {
             return;
         }
         serviceRegistered(serviceName);
     });
     connect(m_systemServiceWatcher, &QDBusServiceWatcher::serviceUnregistered, this, [this](const QString &serviceName) {
         if (!m_dbusSystemServiceNamesFetched) {
             return;
         }
         serviceUnregistered(serviceName);
     });
 }
 
 void DBusServiceObserver::registerPlugin(const KPluginMetaData &pluginMetaData)
 {
     const QString dbusactivation = pluginMetaData.value(QStringLiteral("X-Plasma-DBusActivationService"));
     if (!dbusactivation.isEmpty()) {
         qCDebug(SYSTEM_TRAY) << "Found DBus-able Applet: " << pluginMetaData.pluginId() << dbusactivation;
         QRegularExpression rx = QRegularExpression::fromWildcard(dbusactivation);
         m_dbusActivatableTasks[pluginMetaData.pluginId()] = rx;
 
         const QString watchedService = QString(dbusactivation).replace(QLatin1String(".*"), QLatin1String("*"));
         m_sessionServiceWatcher->addWatchedService(watchedService);
         m_systemServiceWatcher->addWatchedService(watchedService);
     }
 }
 
 void DBusServiceObserver::unregisterPlugin(const QString &pluginId)
 {
     if (m_dbusActivatableTasks.contains(pluginId)) {
         auto rx = m_dbusActivatableTasks.take(pluginId);
         const QString watchedService = rx.pattern().replace(QLatin1String(".*"), QLatin1String("*"));
         m_sessionServiceWatcher->removeWatchedService(watchedService);
         m_systemServiceWatcher->removeWatchedService(watchedService);
     }
 }
 
 bool DBusServiceObserver::isDBusActivable(const QString &pluginId)
 {
     return m_dbusActivatableTasks.contains(pluginId);
 }
 
 /* Loading and unloading Plasmoids when dbus services come and go
  *
  * This works as follows:
  * - we collect a list of plugins and related services in m_dbusActivatableTasks
  * - we query DBus for the list of services, async (initDBusActivatables())
  * - we go over that list, adding tasks when a service and plugin match ({session,system}BusNameFetchFinished())
  * - we start watching for new services, and do the same (serviceRegistered())
  * - whenever a service is gone, we check whether to unload a Plasmoid (serviceUnregistered())
  *
  * Order of events has to be:
  * - create a match rule for new service on DBus daemon
  * - start fetching a list of names
  * - ignore all changes that happen in the meantime
  * - handle the list of all names
  */
 void DBusServiceObserver::initDBusActivatables()
 {
     // fetch list of existing services
     QDBusConnection::sessionBus().interface()->callWithCallback(QStringLiteral("ListNames"),
                                                                 QList<QVariant>(),
                                                                 this,
                                                                 SLOT(sessionBusNameFetchFinished(QStringList)),
                                                                 SLOT(sessionBusNameFetchError(QDBusError)));
 
     QDBusConnection::systemBus().interface()->callWithCallback(QStringLiteral("ListNames"),
                                                                QList<QVariant>(),
                                                                this,
                                                                SLOT(systemBusNameFetchFinished(QStringList)),
                                                                SLOT(systemBusNameFetchError(QDBusError)));
 }
 
 void DBusServiceObserver::sessionBusNameFetchFinished(const QStringList &list)
 {
     for (const QString &serviceName : list) {
         serviceRegistered(serviceName);
     }
 
     m_dbusSessionServiceNamesFetched = true;
 }
 
 void DBusServiceObserver::sessionBusNameFetchError(const QDBusError &error)
 {
     qCWarning(SYSTEM_TRAY) << "Could not get list of available D-Bus services on the session bus:" << error.name() << ":" << error.message();
 }
 
 void DBusServiceObserver::systemBusNameFetchFinished(const QStringList &list)
 {
     for (const QString &serviceName : list) {
         serviceRegistered(serviceName);
     }
 
     m_dbusSystemServiceNamesFetched = true;
 }
 
 void DBusServiceObserver::systemBusNameFetchError(const QDBusError &error)
 {
     qCWarning(SYSTEM_TRAY) << "Could not get list of available D-Bus services on the system bus:" << error.name() << ":" << error.message();
 }
 
 void DBusServiceObserver::serviceRegistered(const QString &service)
 {
     if (service.startsWith(QLatin1Char(':'))) {
         return;
     }
 
     for (auto it = m_dbusActivatableTasks.constBegin(), end = m_dbusActivatableTasks.constEnd(); it != end; ++it) {
         const QString &plugin = it.key();
         if (!m_settings->isEnabledPlugin(plugin)) {
             continue;
         }
 
         const auto &rx = it.value();
         if (rx.match(service).hasMatch()) {
             qCDebug(SYSTEM_TRAY) << "DBus service" << service << "matching" << m_dbusActivatableTasks[plugin] << "appeared. Loading" << plugin;
             Q_EMIT serviceStarted(plugin);
             m_dbusServiceCounts[plugin]++;
         }
     }
 }
 
 void DBusServiceObserver::serviceUnregistered(const QString &service)
 {
     for (auto it = m_dbusActivatableTasks.constBegin(), end = m_dbusActivatableTasks.constEnd(); it != end; ++it) {
         const QString &plugin = it.key();
         if (!m_settings->isEnabledPlugin(plugin)) {
             continue;
         }
 
         const auto &rx = it.value();
         if (rx.match(service).hasMatch()) {
             m_dbusServiceCounts[plugin]--;
             Q_ASSERT(m_dbusServiceCounts[plugin] >= 0);
             if (m_dbusServiceCounts[plugin] == 0) {
                 qCDebug(SYSTEM_TRAY) << "DBus service" << service << "matching" << m_dbusActivatableTasks[plugin] << "disappeared. Unloading" << plugin;
                 Q_EMIT serviceStopped(plugin);
             }
         }
     }
 }