bluezdbus/client: Support pairing during connection establishment

This is achieved by passing ``pairing_callbacks`` to the ``BleakClient``
constructor instead of manually calling ``pair()`` method.

bleak/backends/bluezdbus/client.py

@@ -96,12 +96,9 @@ def __init__(self, address_or_ble_device: Union[BLEDevice, str], **kwargs):
         # used to override mtu_size property
         self._mtu_size: Optional[int] = None
 
-        if kwargs.get("pairing_callbacks"):
-            warnings.warn(
-                "Pairing on connect not yet implemented for BlueZ",
-                RuntimeWarning,
-                stacklevel=2,
-            )
+        self._pairing_callbacks: Optional[BaseBleakAgentCallbacks] = kwargs.get(
+            "pairing_callbacks"
+        )
 
     def close(self):
         self._bus.disconnect()
@@ -193,6 +190,11 @@ def on_value_changed(char_path: str, value: bytes) -> None:
                 #
                 # For additional details see https://github.com/bluez/bluez/issues/89
                 #
+                if self._pairing_callbacks:
+                    # org.bluez.Device1.Pair() will connect to the remote device, initiate
+                    # pairing and then retrieve all SDP records (or GATT primary services).
+                    await self.pair(self._pairing_callbacks)
+
                 if not manager.is_connected(self._device_path):
                     logger.debug("Connecting to BlueZ path %s", self._device_path)
                     async with async_timeout(timeout):
@@ -400,6 +402,7 @@ async def pair(
                     member="Pair",
                 )
             )
+            # TODO: Call "CancelPairing" if this task is cancelled
 
             try:
                 assert_reply(reply)

examples/pairing_agent.py

@@ -59,7 +59,7 @@ async def request_pin(self, device: BLEDevice) -> str:
         return response
 
 
-async def main(addr: str, unpair: bool) -> None:
+async def main(addr: str, unpair: bool, auto: bool) -> None:
     if unpair:
         print("unpairing...")
         try:
@@ -76,16 +76,26 @@ async def main(addr: str, unpair: bool) -> None:
         print("device was not found")
         return
 
-    print("pairing...")
+    if auto:
+        print("connecting and pairing...")
 
-    async with BleakClient(device) as client, AgentCallbacks() as callbacks:
-        try:
-            await client.pair(callbacks)
-            print("pairing successful")
-        except BleakPairingCancelledError:
-            print("paring was canceled")
-        except BleakPairingFailedError:
-            print("pairing failed (bad pin?)")
+        async with AgentCallbacks() as callbacks, BleakClient(
+            device, pairing_callbacks=callbacks
+        ) as client:
+            print(f"connection and pairing to {client.address} successful")
+
+    else:
+        print("connecting...")
+
+        async with BleakClient(device) as client, AgentCallbacks() as callbacks:
+            try:
+                print("pairing...")
+                await client.pair(callbacks)
+                print("pairing successful")
+            except BleakPairingCancelledError:
+                print("paring was canceled")
+            except BleakPairingFailedError:
+                print("pairing failed (bad pin?)")
 
 
 if __name__ == "__main__":
@@ -94,6 +104,9 @@ async def main(addr: str, unpair: bool) -> None:
     parser.add_argument(
         "--unpair", action="store_true", help="unpair first before pairing"
     )
+    parser.add_argument(
+        "--auto", action="store_true", help="automatically pair during connect"
+    )
     args = parser.parse_args()
 
-    asyncio.run(main(args.address, args.unpair))
+    asyncio.run(main(args.address, args.unpair, args.auto))