GATTCharacteristic: Add enableNotificationOrIndication(..)..; DIRECTBT_CHARACTERISTIC_VALUE_CACHE_NOTIFICATION_COMPATv2.1.15

GATTCharacteristic (Java/C++): Add enableNotificationOrIndication(..) and use it as default for BLE active addCharacteristicListener(..).

It is recommended to utilize notification over indication, as its link-layer handshake
and higher potential bandwidth may deliver material higher performance.

+++

Add setting BluetoothFactory.DIRECTBT_CHARACTERISTIC_VALUE_CACHE_NOTIFICATION_COMPAT
(and also document DEBUG and VERBOSE).

DIRECTBT_CHARACTERISTIC_VALUE_CACHE_NOTIFICATION_COMPAT

Have direct_bt provide compatibility to TinyB's BluetoothGattCharacteristic
API: BluetoothGattCharacteristic#getValue() value cache and
BluetoothGattCharacteristic#enableValueNotifications(BluetoothNotification) value notification.

DBTGattCharacteristic benefits from _disabled_ compatibility (and DEBUG)
performance wise, as no listener nor cache needs to be added in this case!

1 files changed, 4 insertions, 0 deletions

diff --git a/api/direct_bt/GATTHandler.hpp b/api/direct_bt/GATTHandler.hpp
index 40162184..3f671fe8 100644
--- a/api/direct_bt/GATTHandler.hpp
+++ b/api/direct_bt/GATTHandler.hpp
@@ -313,6 +313,10 @@ namespace direct_bt {
              * Method enables notification and/or indication for the corresponding characteristic at BLE level.
              * </p>
              * <p>
+             * It is recommended to utilize notification over indication, as its link-layer handshake
+             * and higher potential bandwidth may deliver material higher performance.
+             * </p>
+             * <p>
              * Throws an IllegalArgumentException if the given GATTDescriptor is not a ClientCharacteristicConfiguration.
              * </p>
              */