How to force a Bluetooth pairing pin?

[lilimah]

Hey,

i am writing an apllication in qt on my laptop (Debian 8). This applicatio should connect to other devices like my android smartphones (4.4.2, 5.0.2, 6.0.0). This work great, i can pair and connect, but i want the smartphone and the application to show a pin for pairing. I looked in the documentation and it says
"This signal is only emitted for pairing requests issues by calling requestPairing()." (http://doc.qt.io/qt-5/qbluetoothlocaldevice.html#pairingDisplayConfirmation).

So means this, QT tries first to connect without pin and will use the pin just if something goes wrong? How can i force it to show always a pin? (There is no need for a custom pin.) Some parts of my code:

localDevice = new QBluetoothLocalDevice();

connect(localDevice, SIGNAL(pairingFinished(QBluetoothAddress,QBluetoothLocalDevice::Pairing)), this, SLOT(pairingDone(QBluetoothAddress,QBluetoothLocalDevice::Pairing)));

connect(localDevice, SIGNAL(pairingDisplayConfirmation(const QBluetoothAddress&, QString)), this, SLOT(pairingMyDisplayConfirmation(const QBluetoothAddress&, QString)));

connect(localDevice, SIGNAL(pairingDisplayPinCode(QBluetoothAddress,QString)), this, SLOT(displayPin(QBluetoothAddress,QString)));

...

void MainWindow::doPairingAction()
{
    if (ui->list->count() == 0){
        return;
    }

    if (ui->selectedMac->text().length() == 0 || ui->selectedName->text().length() == 0){
        return;
    }

    QBluetoothAddress address (ui->selectedMac->text());
    if (ui->pair->text() == "Pair") {
        qDebug() << "pair " << address;



        localDevice->requestPairing(address, QBluetoothLocalDevice::Paired);
    } else if (ui->pair->text() == "Unpair") {
        localDevice->requestPairing(address, QBluetoothLocalDevice::Unpaired);
    }
}

void MainWindow::pairingMyDisplayConfirmation(const QBluetoothAddress &address, QString pin){
    qDebug() << "#PAIRING_DISPLAY_CONFIRMATION_PIN: " << pin << "for" << address;
}


void MainWindow::pairingDone(const QBluetoothAddress &address, QBluetoothLocalDevice::Pairing pairing)
{
    QList<QListWidgetItem *> items = ui->list->findItems(address.toString(), Qt::MatchContains);

    if (pairing == QBluetoothLocalDevice::Paired || pairing == QBluetoothLocalDevice::AuthorizedPaired ) {
        for (int var = 0; var < items.count(); ++var) {
            QListWidgetItem *item = items.at(var);
            item->setTextColor(QColor(Qt::green));
            setPairStatus(true);
            qDebug() << "pair " << address << "success";
        }
    } else {
        for (int var = 0; var < items.count(); ++var) {
            QListWidgetItem *item = items.at(var);
            item->setTextColor(QColor(Qt::red));
            setPairStatus(false);
            qDebug() << "pair " << address << "failed";
        }
    }
}


void MainWindow::displayPin(const QBluetoothAddress &address, QString pin)
{
    qDebug() << "#DISPLAY_PIN: " << pin << "for" << address;
}

I know there is no dialog, but if i could debug the message for pin request or confirmation would be great.

Thank You.