Question

I would like to mount a filesystem using QT and DBUS. I subscribed to signal “DeviceAdded” using this small snippet:

 void DBusWatcher::deviceAdded(const QDBusObjectPath &o) {
    QDBusMessage call = QDBusMessage::createMethodCall("org.freedesktop.UDisks", o.path(), "org.freedesktop.DBus.Properties", "GetAll");

    QList<QVariant> args;
    args.append("org.freedesktop.UDisks.Device");
    call.setArguments(args);

    QDBusPendingReply<QVariantMap> reply = DBusConnection::systemBus().asyncCall(call);
    reply.waitForFinished();

    QVariantMap map = reply.value();

    // ...
}

That works pretty fine. My question is, how do I mount this thing? All I have is something like this – and it does not work at all – and with no errors.

QDBusMessage call = QDBusMessage::createMethodCall("org.freedesktop.UDisks", "dont know what to put here!", "org.freedesktop.UDisks.Device", "FilesystemMount");

And now, what action should I use on QDBusConnection::systemBus(): call, asyncCall, callWithCallback? What has to be put as second argument into createMethodCall? Nothing works! Really fustrating!

Answer 1

OK, after struggling for at least 2 days I finally got it! I looked into razer-qt sources, I looked into kdelibs sources but somehow all their dbus stuff did not work. So here is the snippet I’m pretty happy with:

void DBusWatcher::deviceAdded(const QDBusObjectPath &o) {
    QDBusMessage call = QDBusMessage::createMethodCall("org.freedesktop.UDisks", o.path(), "org.freedesktop.DBus.Properties", "GetAll");

    QList<QVariant> args;
    args.append("org.freedesktop.UDisks.Device");
    call.setArguments(args);

    QDBusPendingReply<QVariantMap> reply = QDBusConnection::systemBus().asyncCall(call);
    reply.waitForFinished();

    QVariantMap map = reply.value();
    // now do what you want with the map ;)
    // You will find all available information to the device attached
}

// a class wide pointer to the systembus
// initialized within the constructor of the class
// and deleted in the destructor
dbus = new QDBusInterface(
    "org.freedesktop.UDisks",
    "here comes the path from the QDBusObjectPath.path() object",
    "org.freedesktop.UDisks.Device",
    QDBusConnection::systemBus(),
    this
);

void DbusAction::mountFilesystem() {
    if(dbus->isValid()) {

        QList<QVariant> args;
        args << QVariant(QString()) << QVariant(QStringList());

        QDBusMessage msg = dbus->callWithArgumentList(QDBus::AutoDetect, "FilesystemMount", args);
        if(msg.type() == QDBusMessage::ReplyMessage) {
            QString path = msg.arguments().at(0).toString();
            if(!path.isEmpty()) {
                emit deviceMounted(path);
            } else {
                qDebug() << "sorry, but the path returned is empty";
            }
        } else {
            qDebug() << msg.errorMessage();
        }
    }
}

I’m using Openbox and the latest Udisk(2) stuff running on x64-ArchLinux. Maybe someone can use it too.