// Copyright (C) 2016 The Qt Company Ltd.

// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

// Qt-Security score:significant reason:default

#include <qsessionmanager.h>

#include <qguiapplication.h>

#include <qpa/qplatformsessionmanager.h>

#include <qpa/qplatformintegration.h>

#include <private/qobject_p.h>

#include <private/qguiapplication_p.h>

#include <private/qsessionmanager_p.h>

#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.

    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.

    \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.

    \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

#include "moc_qsessionmanager.cpp"

#endif // QT_NO_SESSIONMANAGER