Do not handle PAIRING_VARIANT_PIN

The user has to enter a pin in such cases. Since QBluetoothLocalDevice
does not have an API to return a pin it makes no sense for QtBluetooth
to handle this type of request. Android will provide its own fall back
form.

This patch is mostly a revert of f8c0572ddc.

Fixes: QTBUG-76565
Task-number: QTBUG-70295
Change-Id: I61062ac84ce508f3b82c7359a60d5c9c5bba86a4
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

src/bluetooth/android/localdevicebroadcastreceiver.cpp

@@ -189,6 +189,14 @@ void LocalDeviceBroadcastReceiver::onReceive(JNIEnv *env, jobject context, jobje
             return;
         case 0: //BluetoothDevice.PAIRING_VARIANT_PIN
         {
+            qCDebug(QT_BT_ANDROID) << "Pairing : PAIRING_VARIANT_PIN -> use Android default handling";
+
+            // The section below is disabled because this Android pairing variant
+            // requires the user to enter a pin. Since QBluetoothLocalDevice does
+            // not have a setPin() equivalent which might be used to return the user's value.
+            // For now we ignore this request. If an app ignores such requests,
+            // Android shows a "fall-back" pin code entry form.
+            /*
             //generate a random key
             const QString pin = QStringLiteral("%1").arg(QRandomGenerator::global()->bounded(1000000),
                                                          6, 10, QLatin1Char('0'));
@@ -225,10 +233,12 @@ void LocalDeviceBroadcastReceiver::onReceive(JNIEnv *env, jobject context, jobje
             }
 
             const QBluetoothAddress address(bluetoothDevice.callObjectMethod<jstring>("getAddress").toString());
-            emit pairingDisplayPinCode(address, pin);
+            emit pairingDisplayPinCode(address, pin);*/
+            break;
         }
         case 2: //BluetoothDevice.PAIRING_VARIANT_PASSKEY_CONFIRMATION
         {
+            qCDebug(QT_BT_ANDROID) << "Pairing : PAIRING_VARIANT_PASSKEY_CONFIRMATION";
             keyExtra = valueForStaticField(JavaNames::BluetoothDevice,
                                            JavaNames::ExtraPairingKey);
             key = intentObject.callMethod<jint>("getIntExtra",

src/bluetooth/qbluetoothlocaldevice_android.cpp

@@ -69,8 +69,6 @@ QBluetoothLocalDevicePrivate::QBluetoothLocalDevicePrivate(
             this, &QBluetoothLocalDevicePrivate::processConnectDeviceChanges);
     connect(receiver, &LocalDeviceBroadcastReceiver::pairingDisplayConfirmation,
             this, &QBluetoothLocalDevicePrivate::processDisplayConfirmation);
-    connect(receiver, &LocalDeviceBroadcastReceiver::pairingDisplayPinCode,
-            this, &QBluetoothLocalDevicePrivate::processDisplayPinCode);
 }
 
 QBluetoothLocalDevicePrivate::~QBluetoothLocalDevicePrivate()
@@ -206,15 +204,6 @@ void QBluetoothLocalDevicePrivate::processDisplayConfirmation(const QBluetoothAd
         return;
 
     emit q_ptr->pairingDisplayConfirmation(address, pin);
-}
-
-void QBluetoothLocalDevicePrivate::processDisplayPinCode(const QBluetoothAddress &address, const QString &pin)
-{
-    // only send pairing notification for pairing requests issued by
-    // this QBluetoothLocalDevice instance
-    if (pendingPairing(address) == -1)
-        return;
-
     emit q_ptr->pairingDisplayPinCode(address, pin);
 }
 

src/bluetooth/qbluetoothlocaldevice_p.h

@@ -113,7 +113,6 @@ private slots:
                                     QBluetoothLocalDevice::Pairing pairing);
     void processConnectDeviceChanges(const QBluetoothAddress &address, bool isConnectEvent);
     void processDisplayConfirmation(const QBluetoothAddress &address, const QString &pin);
-    void processDisplayPinCode(const QBluetoothAddress &address, const QString &pin);
 
 private:
     QBluetoothLocalDevice *q_ptr;