Question

This is my first time using DBus so I’m not entirely sure if I’m going about this the right way. I’m attempting to connect the the Ubuntu One DBus service and obtain login credentials for my app, however the slots I’ve connected to the DBus return signals detailed here never seem to be firing, despite a positive result being returned during the connection.

Before I start looking for errors in the details relating to this specific service, could someone please tell me if this code would even work in the first place, or if I’m done something wrong here?

int main()
{
    UbuntuOneDBus *u1Dbus = new UbuntuOneDBus;
    u1Dbus->init();
}

class UbuntuOneDBus : public QObject
{
  Q_OBJECT

  QString busName;
  QString path;
  QString interface;
  QString method;
  QString signature;

  void connectReturnSignals();

private slots:
  void credentialsFound();
  void credentialsNotFound();
  void credentialsError();

public:
  UbuntuOneDBus();

  void init();
};

UbuntuOneDBus::UbuntuOneDBus()
{
  busName = "com.ubuntuone.Credentials";
  path = "/credentials";
  interface = "com.ubuntuone.CredentialsManagement";
  method = "register";
  signature = "a{ss}";

  connectReturnSignals();
}

void UbuntuOneDBus::init()
{
  QDBusMessage message = QDBusMessage::createMethodCall( busName, path, interface, method );
  QDBusConnection::sessionBus().send( message );
}

void UbuntuOneDBus::connectReturnSignals()
{
  QDBusConnection::sessionBus().connect( busName, path, interface, "CredentialsFound", this, SLOT( credentialsFound() ) );
  QDBusConnection::sessionBus().connect( busName, path, interface, "CredentialsNotFound", this, SLOT( credentialsNotFound() ) );
  QDBusConnection::sessionBus().connect( busName, path, interface, "CredentialsError", this, SLOT( credentialsError() ) );
}

void UbuntuOneDBus::credentialsFound()
{
  qDebug() << "Credentials found";
}

void UbuntuOneDBus::credentialsNotFound()
{
  std::cout << "Credentials not found" << std::endl;
}

void UbuntuOneDBus::credentialsError()
{
  std::cout << "Credentials error" << std::endl;
}

Answer 1

I think that you forgot to run

QDBusConnection QDBusConnection::connectToBus ( BusType type, 
                                                const QString & name )

and then check

bool QDBusConnection::isConnected () const

before invoking

void UbuntuOneDBus::connectReturnSignals()

or run program with some flags, but this should be easier.

I don’t want what is your goal but maybe you should also try

bool QDBusConnection::registerObject ( const QString & path, QObject * object, 
                                       RegisterOptions options = ExportAdaptors )

Here some documentation:
connectToBus

isConnected

registerObject