idle_dbus

/*
 * idle_dbus.cpp - detect desktop idle time
 * Copyright (C) 2022  Vitaly Tonkacheyev
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 */

#include "idle.h"

#include <QDBusConnection>
#include <QDBusConnectionInterface>
#include <QDBusInterface>
#include <QDBusMessage>
#include <QDBusMetaType>
#include <QDBusReply>

// Screen Saver dbus services
static const QLatin1String COMMON_SS_SERV("org.freedesktop.ScreenSaver");
static const QLatin1String COMMON_SS_PATH("/ScreenSaver");
static const QLatin1String KDE_SS_SERV("org.kde.screensaver");
static const QLatin1String GNOME_SS_SERV("org.gnome.Mutter.IdleMonitor");
static const QLatin1String GNOME_SS_PATH("/org/gnome/Mutter/IdleMonitor/Core");
// Screen saver functions
static const QLatin1String GNOME_SS_F("GetIdletime");
static const QLatin1String COMMON_SS_F("GetSessionIdleTime");

class IdlePlatform::Private {
public:
    Private() { }
    QString availableService;
    bool    getServicesAvailable()
    {
        const auto        services     = QDBusConnection::sessionBus().interface()->registeredServiceNames().value();
        const QStringList idleServices = { COMMON_SS_SERV, KDE_SS_SERV, GNOME_SS_SERV };
        // find first available dbus-service
        for (const auto &service : idleServices) {
            if (services.contains(service)) {
                availableService = service;
                return true;
            }
        }
        return false;
    }
};

IdlePlatform::IdlePlatform() { d = new Private; }
IdlePlatform::~IdlePlatform() { delete d; }
bool IdlePlatform::init() { return !d->getServicesAvailable(); }

int IdlePlatform::secondsIdle()
{
    // KDE and freedesktop uses the same path interface and method but gnome uses other
    bool                isNotGnome = d->availableService == COMMON_SS_SERV || d->availableService == KDE_SS_SERV;
    const QLatin1String iface      = isNotGnome ? COMMON_SS_SERV : GNOME_SS_SERV;
    const QLatin1String path       = isNotGnome ? COMMON_SS_PATH : GNOME_SS_PATH;
    const QLatin1String method     = isNotGnome ? COMMON_SS_F : GNOME_SS_F;
    auto                interface  = QDBusInterface(d->availableService, path, iface);
    if (interface.isValid()) {
        QDBusReply<int> reply = interface.call(method);
        // probably reply value for freedesktop and kde need to be converted to seconds
        if (reply.isValid())
            return isNotGnome ? reply.value() / 1000 : reply.value();
    }
    return 0;
}