import asyncio
import logging
import sys
from typing import Dict, List, Literal, NamedTuple, Optional
from uuid import UUID
if sys.version_info >= (3, 12):
from winrt.windows.devices.bluetooth.advertisement import (
BluetoothLEAdvertisementReceivedEventArgs,
BluetoothLEAdvertisementType,
BluetoothLEAdvertisementWatcher,
BluetoothLEAdvertisementWatcherStatus,
BluetoothLEScanningMode,
)
else:
from bleak_winrt.windows.devices.bluetooth.advertisement import (
BluetoothLEAdvertisementReceivedEventArgs,
BluetoothLEAdvertisementType,
BluetoothLEAdvertisementWatcher,
BluetoothLEAdvertisementWatcherStatus,
BluetoothLEScanningMode,
)
from ...assigned_numbers import AdvertisementDataType
from ...uuids import normalize_uuid_str
from ..scanner import AdvertisementData, AdvertisementDataCallback, BaseBleakScanner
logger = logging.getLogger(__name__)
def _format_bdaddr(a: int) -> str:
return ":".join(f"{x:02X}" for x in a.to_bytes(6, byteorder="big"))
def _format_event_args(e: BluetoothLEAdvertisementReceivedEventArgs) -> str:
try:
return f"{_format_bdaddr(e.bluetooth_address)}: {e.advertisement.local_name}"
except Exception:
return _format_bdaddr(e.bluetooth_address)
class _RawAdvData(NamedTuple):
"""
Platform-specific advertisement data.
Windows does not combine advertising data with type SCAN_RSP with other
advertising data like other platforms, so se have to do it ourselves.
"""
adv: BluetoothLEAdvertisementReceivedEventArgs
"""
The advertisement data received from the BluetoothLEAdvertisementWatcher.Received event.
"""
scan: Optional[BluetoothLEAdvertisementReceivedEventArgs]
"""
The scan response for the same device as *adv*.
"""
[docs]class BleakScannerWinRT(BaseBleakScanner):
"""The native Windows Bleak BLE Scanner.
Implemented using `Python/WinRT <https://github.com/Microsoft/xlang/tree/master/src/package/pywinrt/projection/>`_.
Args:
detection_callback:
Optional function that will be called each time a device is
discovered or advertising data has changed.
service_uuids:
Optional list of service UUIDs to filter on. Only advertisements
containing this advertising data will be received.
scanning_mode:
Set to ``"passive"`` to avoid the ``"active"`` scanning mode.
"""
def __init__(
self,
detection_callback: Optional[AdvertisementDataCallback],
service_uuids: Optional[List[str]],
scanning_mode: Literal["active", "passive"],
**kwargs,
):
super(BleakScannerWinRT, self).__init__(detection_callback, service_uuids)
self.watcher = None
self._advertisement_pairs: Dict[int, _RawAdvData] = {}
self._stopped_event = None
# case insensitivity is for backwards compatibility on Windows only
if scanning_mode.lower() == "passive":
self._scanning_mode = BluetoothLEScanningMode.PASSIVE
else:
self._scanning_mode = BluetoothLEScanningMode.ACTIVE
self._signal_strength_filter = kwargs.get("SignalStrengthFilter", None)
self._advertisement_filter = kwargs.get("AdvertisementFilter", None)
self._received_token = None
self._stopped_token = None
def _received_handler(
self,
sender: BluetoothLEAdvertisementWatcher,
event_args: BluetoothLEAdvertisementReceivedEventArgs,
):
"""Callback for AdvertisementWatcher.Received"""
# TODO: Cannot check for if sender == self.watcher in winrt?
logger.debug("Received %s.", _format_event_args(event_args))
# REVISIT: if scanning filters with BluetoothSignalStrengthFilter.OutOfRangeTimeout
# are in place, an RSSI of -127 means that the device has gone out of range and should
# be removed from the list of seen devices instead of processing the advertisement data.
# https://learn.microsoft.com/en-us/uwp/api/windows.devices.bluetooth.bluetoothsignalstrengthfilter.outofrangetimeout
bdaddr = _format_bdaddr(event_args.bluetooth_address)
# Unlike other platforms, Windows does not combine advertising data for
# us (regular advertisement + scan response) so we have to do it manually.
# get the previous advertising data/scan response pair or start a new one
raw_data = self._advertisement_pairs.get(bdaddr, _RawAdvData(None, None))
# update the advertising data depending on the advertising data type
if event_args.advertisement_type == BluetoothLEAdvertisementType.SCAN_RESPONSE:
raw_data = _RawAdvData(raw_data.adv, event_args)
else:
raw_data = _RawAdvData(event_args, raw_data.scan)
self._advertisement_pairs[bdaddr] = raw_data
uuids = []
mfg_data = {}
service_data = {}
local_name = None
tx_power = None
for args in filter(lambda d: d is not None, raw_data):
for u in args.advertisement.service_uuids:
uuids.append(str(u))
for m in args.advertisement.manufacturer_data:
mfg_data[m.company_id] = bytes(m.data)
# local name is empty string rather than None if not present
if args.advertisement.local_name:
local_name = args.advertisement.local_name
try:
if args.transmit_power_level_in_d_bm is not None:
tx_power = args.transmit_power_level_in_d_bm
except AttributeError:
# the transmit_power_level_in_d_bm property was introduce in
# Windows build 19041 so we have a fallback for older versions
for section in args.advertisement.get_sections_by_type(
AdvertisementDataType.TX_POWER_LEVEL
):
tx_power = bytes(section.data)[0]
# Decode service data
for section in args.advertisement.get_sections_by_type(
AdvertisementDataType.SERVICE_DATA_UUID16
):
data = bytes(section.data)
service_data[normalize_uuid_str(f"{data[1]:02x}{data[0]:02x}")] = data[
2:
]
for section in args.advertisement.get_sections_by_type(
AdvertisementDataType.SERVICE_DATA_UUID32
):
data = bytes(section.data)
service_data[
normalize_uuid_str(
f"{data[3]:02x}{data[2]:02x}{data[1]:02x}{data[0]:02x}"
)
] = data[4:]
for section in args.advertisement.get_sections_by_type(
AdvertisementDataType.SERVICE_DATA_UUID128
):
data = bytes(section.data)
service_data[str(UUID(bytes=bytes(data[15::-1])))] = data[16:]
# Use the BLEDevice to populate all the fields for the advertisement data to return
advertisement_data = AdvertisementData(
local_name=local_name,
manufacturer_data=mfg_data,
service_data=service_data,
service_uuids=uuids,
tx_power=tx_power,
rssi=event_args.raw_signal_strength_in_d_bm,
platform_data=(sender, raw_data),
)
device = self.create_or_update_device(
bdaddr, local_name, raw_data, advertisement_data
)
# On Windows, we have to fake service UUID filtering. If we were to pass
# a BluetoothLEAdvertisementFilter to the BluetoothLEAdvertisementWatcher
# with the service UUIDs appropriately set, we would no longer receive
# scan response data (which commonly contains the local device name).
# So we have to do it like this instead.
if self._service_uuids:
for uuid in uuids:
if uuid in self._service_uuids:
break
else:
# if there were no matching service uuids, the don't call the callback
return
self.call_detection_callbacks(device, advertisement_data)
def _stopped_handler(self, sender, e):
logger.debug(
"%s devices found. Watcher status: %r.",
len(self.seen_devices),
sender.status,
)
self._stopped_event.set()
[docs] async def start(self) -> None:
# start with fresh list of discovered devices
self.seen_devices = {}
self._advertisement_pairs.clear()
self.watcher = BluetoothLEAdvertisementWatcher()
self.watcher.scanning_mode = self._scanning_mode
event_loop = asyncio.get_running_loop()
self._stopped_event = asyncio.Event()
self._received_token = self.watcher.add_received(
lambda s, e: event_loop.call_soon_threadsafe(self._received_handler, s, e)
)
self._stopped_token = self.watcher.add_stopped(
lambda s, e: event_loop.call_soon_threadsafe(self._stopped_handler, s, e)
)
if self._signal_strength_filter is not None:
self.watcher.signal_strength_filter = self._signal_strength_filter
if self._advertisement_filter is not None:
self.watcher.advertisement_filter = self._advertisement_filter
self.watcher.start()
[docs] async def stop(self) -> None:
self.watcher.stop()
if self.watcher.status == BluetoothLEAdvertisementWatcherStatus.STOPPING:
await self._stopped_event.wait()
else:
logger.debug(
"skipping waiting for stop because status is %r",
self.watcher.status,
)
try:
self.watcher.remove_received(self._received_token)
self.watcher.remove_stopped(self._stopped_token)
except Exception as e:
logger.debug("Could not remove event handlers: %s", e)
self._stopped_token = None
self._received_token = None
self.watcher = None
[docs] def set_scanning_filter(self, **kwargs) -> None:
"""Set a scanning filter for the BleakScanner.
Keyword Args:
SignalStrengthFilter (``Windows.Devices.Bluetooth.BluetoothSignalStrengthFilter``): A
BluetoothSignalStrengthFilter object used for configuration of Bluetooth
LE advertisement filtering that uses signal strength-based filtering.
AdvertisementFilter (Windows.Devices.Bluetooth.Advertisement.BluetoothLEAdvertisementFilter): A
BluetoothLEAdvertisementFilter object used for configuration of Bluetooth LE
advertisement filtering that uses payload section-based filtering.
"""
if "SignalStrengthFilter" in kwargs:
# TODO: Handle SignalStrengthFilter parameters
self._signal_strength_filter = kwargs["SignalStrengthFilter"]
if "AdvertisementFilter" in kwargs:
# TODO: Handle AdvertisementFilter parameters
self._advertisement_filter = kwargs["AdvertisementFilter"]