File indexing completed on 2024-04-21 16:17:32

 /*
  * SPDX-FileCopyrightText: 2014 Daniel Vratil <dvratil@redhat.com>
  * SPDX-FileCopyrightText: 2015 Sebastian Kügler <sebas@kde.org>
  *
  * SPDX-License-Identifier: LGPL-2.1-or-later
  *
  */
 
 /**
  * WARNING: This header is *not* part of public API and is subject to change.
  * There are not guarantees or API or ABI stability or compatibility between
  * releases
  */
 
 #ifndef KSCREEN_BACKENDMANAGER_H
 #define KSCREEN_BACKENDMANAGER_H
 
 #include <QDBusServiceWatcher>
 #include <QEventLoop>
 #include <QFileInfoList>
 #include <QObject>
 #include <QPluginLoader>
 #include <QProcess>
 #include <QTimer>
 
 #include "kscreen_export.h"
 #include "types.h"
 
 class QDBusPendingCallWatcher;
 class OrgKdeKscreenBackendInterface;
 
 namespace KScreen
 {
 class AbstractBackend;
 
 class KSCREEN_EXPORT BackendManager : public QObject
 {
     Q_OBJECT
 
 public:
     enum Method {
         InProcess,
         OutOfProcess,
     };
 
     static BackendManager *instance();
     ~BackendManager() override;
 
     KScreen::ConfigPtr config() const;
     void setConfig(KScreen::ConfigPtr c);
 
     /** Choose which backend to use
      *
      * This method uses a couple of heuristics to pick the backend to be loaded:
      * - If the @p backend argument is specified and not empty it's used to filter the
      *   available backend list
      * - If specified, the KSCREEN_BACKEND env var is considered (case insensitive)
      * - Otherwise, the wayland backend is picked when the runtime platform is Wayland
      *   (we assume kwin in this case
      * - Otherwise, if the runtime platform is X11, the XRandR backend is picked
      * - If neither is the case, we fall back to the QScreen backend, since that is the
      *   most generally applicable and may work on platforms not explicitly supported
      *
      * @return the backend plugin to load
      * @since 5.7
      */
     static QFileInfo preferredBackend(const QString &backend = QString());
 
     /** List installed backends
      * @return a list of installed backend plugins
      * @since 5.7
      */
     static QFileInfoList listBackends();
 
     /** Set arguments map which a backend may use on initialization.
      *
      * Calling this method after a backend has been initialized will have no effect.
      * Arguments map will NOT be automatically cleared on backend shutdown; which
      * makes possible setting arguments before restarting backend in tests.
      *
      * @param map of arbitrary arguments for backends; each backend is free to interpret
      * them as it sees fit.
      * @since 5.27
      */
     void setBackendArgs(const QVariantMap &arguments);
 
     /** Get arguments map which a backend may use on initialization.
      *
      * @return map of arbitrary arguments for backends.
      * @since 5.27
      */
     QVariantMap getBackendArgs();
 
     /** Encapsulates the plugin loading logic.
      *
      * @param loader a pointer to the QPluginLoader, the caller is
      * responsible for its memory management.
      * @param name name of the backend plugin
      * @param arguments arguments, used for unit tests
      * @return a pointer to the backend loaded from the plugin
      * @since 5.6
      */
     static KScreen::AbstractBackend *loadBackendPlugin(QPluginLoader *loader, const QString &name, const QVariantMap &arguments);
 
     KScreen::AbstractBackend *loadBackendInProcess(const QString &name);
 
     BackendManager::Method method() const;
     void setMethod(BackendManager::Method m);
 
     // For out-of-process operation
     void requestBackend();
     void shutdownBackend();
 
 Q_SIGNALS:
     void backendReady(OrgKdeKscreenBackendInterface *backend);
 
 private Q_SLOTS:
     void emitBackendReady();
 
     void startBackend(const QString &backend = QString(), const QVariantMap &arguments = QVariantMap());
     void onBackendRequestDone(QDBusPendingCallWatcher *watcher);
 
     void backendServiceUnregistered(const QString &serviceName);
 
 private:
     friend class SetInProcessOperation;
     friend class InProcessConfigOperationPrivate;
     friend class SetConfigOperation;
     friend class SetConfigOperationPrivate;
 
     explicit BackendManager();
     static BackendManager *sInstance;
 
     void initMethod();
 
     // For out-of-process operation
     void invalidateInterface();
     void backendServiceReady();
 
     static const int sMaxCrashCount;
     OrgKdeKscreenBackendInterface *mInterface;
     int mCrashCount;
 
     QString mBackendService;
     QDBusServiceWatcher mServiceWatcher;
     KScreen::ConfigPtr mConfig;
     QVariantMap mBackendArguments;
     QTimer mResetCrashCountTimer;
     bool mShuttingDown;
     int mRequestsCounter;
     QEventLoop mShutdownLoop;
 
     // For in-process operation
     QPluginLoader *mLoader;
     KScreen::AbstractBackend *mInProcessBackend;
 
     Method mMethod;
 };
 
 }
 
 #endif // KSCREEN_BACKENDMANAGER_H