/**************************************************************************** ** ** Copyright (C) 2016 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the QtGui module of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:LGPL$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** GNU Lesser General Public License Usage ** Alternatively, this file may be used under the terms of the GNU Lesser ** General Public License version 3 as published by the Free Software ** Foundation and appearing in the file LICENSE.LGPL3 included in the ** packaging of this file. Please review the following information to ** ensure the GNU Lesser General Public License version 3 requirements ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. ** ** GNU General Public License Usage ** Alternatively, this file may be used under the terms of the GNU ** General Public License version 2.0 or (at your option) the GNU General ** Public license version 3 or any later version approved by the KDE Free ** Qt Foundation. The licenses are as published by the Free Software ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 ** included in the packaging of this file. Please review the following ** information to ensure the GNU General Public License requirements will ** be met: https://www.gnu.org/licenses/gpl-2.0.html and ** https://www.gnu.org/licenses/gpl-3.0.html. ** ** $QT_END_LICENSE$ ** ****************************************************************************/ #include #include #include #include #include #include #include #ifndef QT_NO_SESSIONMANAGER QT_BEGIN_NAMESPACE /*! \class QSessionManager \brief The QSessionManager class provides access to the session manager. \inmodule QtGui A session manager in a desktop environment (in which Qt GUI applications live) keeps track of a session, which is a group of running applications, each of which has a particular state. The state of an application contains (most notably) the documents the application has open and the position and size of its windows. The session manager is used to save the session, e.g., when the machine is shut down, and to restore a session, e.g., when the machine is started up. We recommend that you use QSettings to save an application's settings, for example, window positions, recently used files, etc. When the application is restarted by the session manager, you can restore the settings. QSessionManager provides an interface between the application and the platform's session manager. In Qt, session management requests for action are handled by the two signals QGuiApplication::commitDataRequest() and QGuiApplication::saveStateRequest(). Both provide a reference to a QSessionManager object as argument. The session manager can only be accessed in slots invoked by these signals. \warning If you use QSessionManager, you should disable fallback session management: QGuiApplication::setFallbackSessionManagementEnabled(). No user interaction is possible \e unless the application gets explicit permission from the session manager. You ask for permission by calling allowsInteraction() or, if it is really urgent, allowsErrorInteraction(). Qt does not enforce this, but the session manager may. You can try to abort the shutdown process by calling cancel(). For sophisticated session managers provided on Unix/X11, QSessionManager offers further possibilities to fine-tune an application's session management behavior: setRestartCommand(), setDiscardCommand(), setRestartHint(), setProperty(), requestPhase2(). See the respective function descriptions for further details. \sa QGuiApplication, {Session Management} */ /*! \enum QSessionManager::RestartHint This enum type defines the circumstances under which this application wants to be restarted by the session manager. The current values are: \value RestartIfRunning If the application is still running when the session is shut down, it wants to be restarted at the start of the next session. \value RestartAnyway The application wants to be started at the start of the next session, no matter what. (This is useful for utilities that run just after startup and then quit.) \value RestartImmediately The application wants to be started immediately whenever it is not running. \value RestartNever The application does not want to be restarted automatically. The default hint is \c RestartIfRunning. */ QSessionManagerPrivate::QSessionManagerPrivate(const QString &id, const QString &key) : QObjectPrivate() { if (qApp->testAttribute(Qt::AA_DisableSessionManager)) { platformSessionManager = new QPlatformSessionManager(id, key); } else { platformSessionManager = QGuiApplicationPrivate::platformIntegration()->createPlatformSessionManager(id, key); } Q_ASSERT_X(platformSessionManager, "Platform session management", "No platform session management, should use the default implementation"); } QSessionManagerPrivate::~QSessionManagerPrivate() { delete platformSessionManager; platformSessionManager = nullptr; } QSessionManager::QSessionManager(QGuiApplication *app, QString &id, QString &key) : QObject(*(new QSessionManagerPrivate(id, key)), app) { } QSessionManager::~QSessionManager() { } /*! Returns the identifier of the current session. If the application has been restored from an earlier session, this identifier is the same as it was in the earlier session. \sa sessionKey(), QGuiApplication::sessionId() */ QString QSessionManager::sessionId() const { Q_D(const QSessionManager); return d->platformSessionManager->sessionId(); } /*! \fn QString QSessionManager::sessionKey() const Returns the session key in the current session. If the application has been restored from an earlier session, this key is the same as it was when the previous session ended. The session key changes with every call of commitData() or saveState(). \sa sessionId(), QGuiApplication::sessionKey() */ QString QSessionManager::sessionKey() const { Q_D(const QSessionManager); return d->platformSessionManager->sessionKey(); } /*! Asks the session manager for permission to interact with the user. Returns true if interaction is permitted; otherwise returns \c false. The rationale behind this mechanism is to make it possible to synchronize user interaction during a shutdown. Advanced session managers may ask all applications simultaneously to commit their data, resulting in a much faster shutdown. When the interaction is completed we strongly recommend releasing the user interaction semaphore with a call to release(). This way, other applications may get the chance to interact with the user while your application is still busy saving data. (The semaphore is implicitly released when the application exits.) If the user decides to cancel the shutdown process during the interaction phase, you must tell the session manager that this has happened by calling cancel(). Here's an example of how an application's QGuiApplication::commitDataRequest() might be implemented: \snippet code/src_gui_kernel_qguiapplication.cpp 1 If an error occurred within the application while saving its data, you may want to try allowsErrorInteraction() instead. \sa QGuiApplication::commitDataRequest(), release(), cancel() */ bool QSessionManager::allowsInteraction() { Q_D(QSessionManager); return d->platformSessionManager->allowsInteraction(); } /*! Returns \c true if error interaction is permitted; otherwise returns \c false. This is similar to allowsInteraction(), but also enables the application to tell the user about any errors that occur. Session managers may give error interaction requests higher priority, which means that it is more likely that an error interaction is permitted. However, you are still not guaranteed that the session manager will allow interaction. \sa allowsInteraction(), release(), cancel() */ bool QSessionManager::allowsErrorInteraction() { Q_D(QSessionManager); return d->platformSessionManager->allowsErrorInteraction(); } /*! Releases the session manager's interaction semaphore after an interaction phase. \sa allowsInteraction(), allowsErrorInteraction() */ void QSessionManager::release() { Q_D(QSessionManager); d->platformSessionManager->release(); } /*! Tells the session manager to cancel the shutdown process. Applications should not call this function without asking the user first. \sa allowsInteraction(), allowsErrorInteraction() */ void QSessionManager::cancel() { Q_D(QSessionManager); d->platformSessionManager->cancel(); } /*! Sets the application's restart hint to \a hint. On application startup, the hint is set to \c RestartIfRunning. \note These flags are only hints, a session manager may or may not respect them. We recommend setting the restart hint in QGuiApplication::saveStateRequest() because most session managers perform a checkpoint shortly after an application's startup. \sa restartHint() */ void QSessionManager::setRestartHint(QSessionManager::RestartHint hint) { Q_D(QSessionManager); d->platformSessionManager->setRestartHint(hint); } /*! \fn QSessionManager::RestartHint QSessionManager::restartHint() const Returns the application's current restart hint. The default is \c RestartIfRunning. \sa setRestartHint() */ QSessionManager::RestartHint QSessionManager::restartHint() const { Q_D(const QSessionManager); return d->platformSessionManager->restartHint(); } /*! If the session manager is capable of restoring sessions it will execute \a command in order to restore the application. The command defaults to \snippet code/src_gui_kernel_qguiapplication.cpp 2 The \c -session option is mandatory; otherwise QGuiApplication cannot tell whether it has been restored or what the current session identifier is. See QGuiApplication::isSessionRestored() and QGuiApplication::sessionId() for details. If your application is very simple, it may be possible to store the entire application state in additional command line options. This is usually a very bad idea because command lines are often limited to a few hundred bytes. Instead, use QSettings, temporary files, or a database for this purpose. By marking the data with the unique sessionId(), you will be able to restore the application in a future session. \sa restartCommand(), setDiscardCommand(), setRestartHint() */ void QSessionManager::setRestartCommand(const QStringList &command) { Q_D(QSessionManager); d->platformSessionManager->setRestartCommand(command); } /*! Returns the currently set restart command. To iterate over the list, you can use the \l foreach pseudo-keyword: \snippet code/src_gui_kernel_qguiapplication.cpp 3 \sa setRestartCommand(), restartHint() */ QStringList QSessionManager::restartCommand() const { Q_D(const QSessionManager); return d->platformSessionManager->restartCommand(); } /*! Sets the discard command to the given \a command. \sa discardCommand(), setRestartCommand() */ void QSessionManager::setDiscardCommand(const QStringList &command) { Q_D(QSessionManager); d->platformSessionManager->setDiscardCommand(command); } /*! Returns the currently set discard command. To iterate over the list, you can use the \l foreach pseudo-keyword: \snippet code/src_gui_kernel_qguiapplication.cpp 4 \sa setDiscardCommand(), restartCommand(), setRestartCommand() */ QStringList QSessionManager::discardCommand() const { Q_D(const QSessionManager); return d->platformSessionManager->discardCommand(); } /*! \overload Low-level write access to the application's identification and state records are kept in the session manager. The property called \a name has its value set to the string \a value. */ void QSessionManager::setManagerProperty(const QString &name, const QString &value) { Q_D(QSessionManager); d->platformSessionManager->setManagerProperty(name, value); } /*! Low-level write access to the application's identification and state record are kept in the session manager. The property called \a name has its value set to the string list \a value. */ void QSessionManager::setManagerProperty(const QString &name, const QStringList &value) { Q_D(QSessionManager); d->platformSessionManager->setManagerProperty(name, value); } /*! Returns \c true if the session manager is currently performing a second session management phase; otherwise returns \c false. \sa requestPhase2() */ bool QSessionManager::isPhase2() const { Q_D(const QSessionManager); return d->platformSessionManager->isPhase2(); } /*! Requests a second session management phase for the application. The application may then return immediately from the QGuiApplication::commitDataRequest() or QApplication::saveStateRequest() function, and they will be called again once most or all other applications have finished their session management. The two phases are useful for applications such as the X11 window manager that need to store information about another application's windows and therefore have to wait until these applications have completed their respective session management tasks. \note If another application has requested a second phase it may get called before, simultaneously with, or after your application's second phase. \sa isPhase2() */ void QSessionManager::requestPhase2() { Q_D(QSessionManager); d->platformSessionManager->requestPhase2(); } QT_END_NAMESPACE #endif // QT_NO_SESSIONMANAGER