Screen locker in Qt

Are the开发者_如何学编程re any Qt based screen lockers on linux systems ?

i.e. 4 pin digit or password screen locker ?

Any reference will be greatly appreciated.

On linux, the screen locking is done by the screensavers, and the password is the one from the user linux account.

You can use QProcess to run a command line and check if it was successful:

• gnome-screensaver-command --lock
• xscreensaver-command --lock
• qdbus org.freedesktop.ScreenSaver /ScreenSaver Lock
• qdbus org.gnome.ScreenSaver /ScreenSaver Lock
• xlock

And/or use QtDBus module to do the same thing

// Tries to lock the screen and returns true if successful 
bool LockScreenWithDBus() {
    QDBusConnection bus = QDBusConnection::sessionBus();
    if(!bus.isConnected())
        return false;

    QStringList services;       
    services << "org.freedesktop.ScreenSaver"             
             << "org.gnome.ScreenSaver"
    // These last two are probably not necessary, because kde uses freedesktop
    // conventions for dbus
             << "org.kde.ScreenSaver"
             << "org.kde.krunner";           

    foreach(QString service, services) {        
        QDBusInterface screenSaverInterface(service, "/ScreenSaver",
                                            QString(), bus);
        if (!screenSaverInterface.isValid())
            continue;       
        QDBusReply<void> reply = screenSaverInterface.call("Lock");
        if (reply.isValid())
            return true;
    }
    return false;
}

You can create a top level FrameLess Semi transparent QWidget of Screen Height and screen width and in its center place your Textbox for password asking.