Source code for bleak.backends.winrt.client

# -*- coding: utf-8 -*-
# Created on 2020-08-19 by hbldh <henrik.blidh@nedomkull.com>
"""
BLE Client for Windows 10 systems, implemented with WinRT.
"""
import sys
from typing import TYPE_CHECKING

if TYPE_CHECKING:
    if sys.platform != "win32":
        assert False, "This backend is only available on Windows"

import asyncio
import logging
import uuid
from collections.abc import Callable
from contextvars import Context
from ctypes import WinError
from typing import Any, Generic, Optional, Protocol, Sequence, TypeVar, Union, cast
from warnings import warn

if sys.version_info < (3, 12):
    from typing_extensions import Buffer, override
else:
    from collections.abc import Buffer
    from typing import override

if sys.version_info < (3, 11):
    from async_timeout import timeout as async_timeout
    from typing_extensions import Self, assert_never
else:
    from asyncio import timeout as async_timeout
    from typing import Self, assert_never

from winrt.system import Object
from winrt.windows.devices.bluetooth import (
    BluetoothAddressType,
    BluetoothCacheMode,
    BluetoothError,
    BluetoothLEDevice,
)
from winrt.windows.devices.bluetooth.genericattributeprofile import (
    GattCharacteristic,
    GattCharacteristicProperties,
    GattClientCharacteristicConfigurationDescriptorValue,
    GattCommunicationStatus,
    GattDescriptor,
    GattDeviceService,
    GattSession,
    GattSessionStatus,
    GattSessionStatusChangedEventArgs,
    GattValueChangedEventArgs,
    GattWriteOption,
)
from winrt.windows.devices.enumeration import (
    DeviceInformation,
    DeviceInformationCustomPairing,
    DevicePairingKinds,
    DevicePairingProtectionLevel,
    DevicePairingRequestedEventArgs,
    DevicePairingResultStatus,
    DeviceUnpairingResultStatus,
)
from winrt.windows.foundation import (
    AsyncStatus,
    EventRegistrationToken,
    IAsyncOperation,
)
from winrt.windows.storage.streams import Buffer as WinBuffer

from bleak import BleakScanner
from bleak.args.winrt import WinRTClientArgs as _WinRTClientArgs
from bleak.assigned_numbers import gatt_char_props_to_strs
from bleak.backends.characteristic import BleakGATTCharacteristic
from bleak.backends.client import BaseBleakClient, NotifyCallback
from bleak.backends.descriptor import BleakGATTDescriptor
from bleak.backends.device import BLEDevice
from bleak.backends.service import BleakGATTService, BleakGATTServiceCollection
from bleak.backends.winrt.scanner import BleakScannerWinRT, RawAdvData
from bleak.exc import PROTOCOL_ERROR_CODES, BleakDeviceNotFoundError, BleakError

logger = logging.getLogger(__name__)


def __getattr__(name: str):
    if name == "WinRTClientArgs":
        warn(
            "importing WinRTClientArgs from bleak.backends.winrt.client is deprecated, use bleak.args.winrt instead",
            DeprecationWarning,
            stacklevel=2,
        )
        return _WinRTClientArgs
    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")


class _Result(Protocol):
    @property
    def status(self) -> GattCommunicationStatus: ...
    @property
    def protocol_error(self) -> Optional[int]: ...


def _address_to_int(address: str) -> int:
    """Converts the Bluetooth device address string to its representing integer

    Args:
        address (str): Bluetooth device address to convert

    Returns:
        int: integer representation of the given Bluetooth device address
    """
    _address_separators = [":", "-"]
    for char in _address_separators:
        address = address.replace(char, "")

    return int(address, base=16)


def _ensure_success(result: _Result, attr: Optional[str], fail_msg: str) -> Any:
    """
    Ensures that *status* is ``GattCommunicationStatus.SUCCESS``, otherwise
    raises ``BleakError``.

    Args:
        result: The result returned by a WinRT API method.
        attr: The name of the attribute containing the result.
        fail_msg: A message to include in the exception.
    """
    status = result.status if hasattr(result, "status") else result

    if status == GattCommunicationStatus.SUCCESS:
        return None if attr is None else getattr(result, attr)

    if status == GattCommunicationStatus.PROTOCOL_ERROR:
        assert result.protocol_error is not None
        err = PROTOCOL_ERROR_CODES.get(result.protocol_error, "Unknown")
        raise BleakError(
            f"{fail_msg}: Protocol Error 0x{result.protocol_error:02X}: {err}"
        )

    if status == GattCommunicationStatus.ACCESS_DENIED:
        raise BleakError(f"{fail_msg}: Access Denied")

    if status == GattCommunicationStatus.UNREACHABLE:
        raise BleakError(f"{fail_msg}: Unreachable")

    raise BleakError(f"{fail_msg}: Unexpected status code 0x{status:02X}")


[docs] class BleakClientWinRT(BaseBleakClient): """Native Windows Bleak Client. Args: address_or_ble_device (str or BLEDevice): The Bluetooth address of the BLE peripheral to connect to or the ``BLEDevice`` object representing it. services: Optional set of service UUIDs that will be used. winrt (dict): A dictionary of Windows-specific configuration values. **timeout (float): Timeout for required ``BleakScanner.find_device_by_address`` call. Defaults to 10.0. """ def __init__( self, address_or_ble_device: Union[BLEDevice, str], services: Optional[set[str]] = None, *, winrt: _WinRTClientArgs, **kwargs: Any, ): super(BleakClientWinRT, self).__init__(address_or_ble_device, **kwargs) # Backend specific. WinRT objects. if isinstance(address_or_ble_device, BLEDevice): data: RawAdvData = address_or_ble_device.details args = data.adv or data.scan assert args self._device_info = args.bluetooth_address else: self._device_info = None self._requested_services = ( [uuid.UUID(s) for s in services] if services else None ) self._requester: Optional[BluetoothLEDevice] = None self._services_changed_events: list[asyncio.Event] = [] self._session_active_events: list[asyncio.Event] = [] self._session: Optional[GattSession] = None self._notification_callbacks: dict[int, EventRegistrationToken] = {} # os-specific options self._use_cached_services = winrt.get("use_cached_services") self._address_type = winrt.get("address_type") self._retry_on_services_changed = False self._session_services_changed_token: Optional[EventRegistrationToken] = None self._session_status_changed_token: Optional[EventRegistrationToken] = None self._max_pdu_size_changed_token: Optional[EventRegistrationToken] = None def __str__(self) -> str: return f"{type(self).__name__} ({self.address})" # Connectivity methods async def _create_requester(self, bluetooth_address: int) -> BluetoothLEDevice: if self._address_type is not None: requester = await BluetoothLEDevice.from_bluetooth_address_with_bluetooth_address_type_async( bluetooth_address, ( BluetoothAddressType.PUBLIC if self._address_type == "public" else BluetoothAddressType.RANDOM ), ) else: requester = await BluetoothLEDevice.from_bluetooth_address_async( bluetooth_address ) # https://github.com/microsoft/Windows-universal-samples/issues/1089#issuecomment-487586755 if requester is None: raise BleakDeviceNotFoundError( self.address, f"Device with address {self.address} was not found." ) return requester
[docs] @override async def connect(self, pair: bool, **kwargs: Any) -> None: """Connect to the specified GATT server. Keyword Args: timeout (float): Timeout for required ``BleakScanner.find_device_by_address`` call. Defaults to 10.0. """ # Try to find the desired device. timeout = kwargs.get("timeout", self._timeout) if self._device_info is None: device = await BleakScanner.find_device_by_address( self.address, timeout=timeout, backend=BleakScannerWinRT ) if device is None: raise BleakDeviceNotFoundError( self.address, f"Device with address {self.address} was not found." ) data: RawAdvData = device.details args = data.adv or data.scan assert args self._device_info = args.bluetooth_address logger.debug("Connecting to BLE device @ %s", self.address) loop = asyncio.get_running_loop() self._requester = await self._create_requester(self._device_info) if pair: await self.pair(**kwargs) def handle_services_changed() -> None: if not self._services_changed_events: logger.warning("%s: unhandled services changed event", self.address) else: for event in self._services_changed_events: event.set() def services_changed_handler(sender: BluetoothLEDevice, args: Object) -> None: logger.debug("%s: services changed", self.address) loop.call_soon_threadsafe(handle_services_changed) self._services_changed_token = self._requester.add_gatt_services_changed( services_changed_handler ) # Called on disconnect event or on failure to connect. def handle_disconnect() -> None: if self._requester: if self._services_changed_token: self._requester.remove_gatt_services_changed( self._services_changed_token ) self._services_changed_token = None logger.debug("closing requester") self._requester.close() self._requester = None if self._session: if self._session_status_changed_token: self._session.remove_session_status_changed( self._session_status_changed_token ) self._session_status_changed_token = None if self._max_pdu_size_changed_token: self._session.remove_max_pdu_size_changed( self._max_pdu_size_changed_token ) self._max_pdu_size_changed_token = None logger.debug("closing session") self._session.close() self._session = None is_connect_complete = False def handle_session_status_changed( args: GattSessionStatusChangedEventArgs, ) -> None: if args.error != BluetoothError.SUCCESS: logger.error("Unhandled GATT error %r", args.error) if args.status == GattSessionStatus.ACTIVE: for e in self._session_active_events: e.set() # Don't run this if we have not exited from the connect method yet. # Cleanup is handled by the connect method in that case. elif args.status == GattSessionStatus.CLOSED and is_connect_complete: if self._disconnected_callback: self._disconnected_callback() handle_disconnect() # this is the WinRT event handler will be called on another thread def session_status_changed_event_handler( sender: GattSession, args: GattSessionStatusChangedEventArgs ): logger.debug( "session_status_changed_event_handler: id: %s, error: %r, status: %r", sender.device_id.id, args.error, args.status, ) loop.call_soon_threadsafe(handle_session_status_changed, args) def max_pdu_size_changed_handler(sender: GattSession, args: Object) -> None: try: max_pdu_size = sender.max_pdu_size except OSError: # There is a race condition where this event was already # queued when the GattSession object was closed. In that # case, we get a Windows error which we can just ignore. return logger.debug("max_pdu_size_changed_handler: %d", max_pdu_size) # Start a GATT Session to connect event = asyncio.Event() self._session_active_events.append(event) try: self._session = await GattSession.from_device_id_async( self._requester.bluetooth_device_id ) if not self._session.can_maintain_connection: raise BleakError("device does not support GATT sessions") self._session_status_changed_token = ( self._session.add_session_status_changed( session_status_changed_event_handler ) ) # If the session is already active, we need to set the event since # the session_status_changed event won't fire. This happens, e.g., # when pairing before connecting which causes the device to already # be connected. if self._session.session_status == GattSessionStatus.ACTIVE: event.set() self._max_pdu_size_changed_token = self._session.add_max_pdu_size_changed( max_pdu_size_changed_handler ) services_changed_event = asyncio.Event() self._services_changed_events.append(services_changed_event) try: # Windows does not support explicitly connecting to a device. # Instead it has the concept of a GATT session that is owned # by the calling program. self._session.maintain_connection = True # This keeps the device connected until we set maintain_connection = False. cache_mode = None if self._use_cached_services is not None: cache_mode = ( BluetoothCacheMode.CACHED if self._use_cached_services else BluetoothCacheMode.UNCACHED ) # if we receive a services changed event before get_gatt_services_async() # finishes, we need to call it again with BluetoothCacheMode.CACHED # to ensure we have the correct services as described in # https://learn.microsoft.com/en-us/uwp/api/windows.devices.bluetooth.bluetoothledevice.gattserviceschanged service_cache_mode = cache_mode async with async_timeout(timeout): if self._retry_on_services_changed: while True: services_changed_event.clear() services_changed_event_task = asyncio.create_task( services_changed_event.wait() ) get_services_task = asyncio.create_task( self._get_services( service_cache_mode=service_cache_mode, cache_mode=cache_mode, ) ) _, pending = await asyncio.wait( [services_changed_event_task, get_services_task], return_when=asyncio.FIRST_COMPLETED, ) for p in pending: p.cancel() if not services_changed_event.is_set(): # services did not change while getting services, # so this is the final result self.services = get_services_task.result() break logger.debug( "%s: restarting get services due to services changed event", self.address, ) service_cache_mode = BluetoothCacheMode.CACHED # ensure the task ran to completion to avoid OSError # on next call to get_services() try: await get_services_task except OSError: pass except asyncio.CancelledError: pass else: self.services = await self._get_services( service_cache_mode=service_cache_mode, cache_mode=cache_mode, ) # a connection may not be made until we request info from the # device, so we have to get services before the GATT session # is set to active await event.wait() is_connect_complete = True finally: self._services_changed_events.remove(services_changed_event) except BaseException: handle_disconnect() raise finally: self._session_active_events.remove(event)
[docs] @override async def disconnect(self) -> None: """Disconnect from the specified GATT server.""" logger.debug("Disconnecting from BLE device...") assert self.services # Remove notifications. for handle, event_handler_token in list(self._notification_callbacks.items()): char = self.services.get_characteristic(handle) assert char gatt_char = cast(GattCharacteristic, char.obj) gatt_char.remove_value_changed(event_handler_token) self._notification_callbacks.clear() # Dispose all service components that we have requested and created. if self.services: # HACK: sometimes GattDeviceService.Close() hangs forever, so we # add a delay to give the Windows Bluetooth stack some time to # "settle" before closing the services await asyncio.sleep(0.1) for service in self.services: service.obj.close() self.services = None if self._session: self._session.close() self._session = None if self._requester: self._requester.close() self._requester = None
@property @override def is_connected(self) -> bool: """Check connection status between this client and the server. Returns: Boolean representing connection status. """ return ( False if self._session is None else self._session.session_status == GattSessionStatus.ACTIVE ) @property @override def mtu_size(self) -> int: """Get ATT MTU size for active connection""" return self._session.max_pdu_size
[docs] @override async def pair( self, **kwargs: Any, ) -> None: """Attempts to pair with the device. Keyword Args: protection_level (int): A ``DevicePairingProtectionLevel`` enum value: 1. None - Pair the device using no levels of protection. 2. Encryption - Pair the device using encryption. 3. EncryptionAndAuthentication - Pair the device using encryption and authentication. .. versionchanged:: 1.0 Issues :class:`DeprecationWarning` if used. The default behavior has changed and this argument should no longer be needed. """ assert self._requester # New local device information object created since the object from the requester isn't updated device_information = await DeviceInformation.create_from_id_async( self._requester.device_information.id ) if device_information.pairing.is_paired: logging.debug("Device is already paired. Skipping pairing.") return if not device_information.pairing.can_pair: raise BleakError("Device does not support pairing") protection_level = kwargs.get("protection_level") # Currently only supporting Just Works solutions... ceremony = DevicePairingKinds.CONFIRM_ONLY custom_pairing = device_information.pairing.custom def handler( sender: DeviceInformationCustomPairing, args: DevicePairingRequestedEventArgs, ): args.accept() pairing_requested_token = custom_pairing.add_pairing_requested(handler) try: if protection_level is not None: warn( "protection_level is deprecated and will be removed in a future version. The default protection level has changed, so it should be safe to omit this argument.", DeprecationWarning, 2, ) pairing_result = await custom_pairing.pair_with_protection_level_async( ceremony, protection_level ) else: for level in ( DevicePairingProtectionLevel.ENCRYPTION_AND_AUTHENTICATION, DevicePairingProtectionLevel.ENCRYPTION, ): pairing_result = ( await custom_pairing.pair_with_protection_level_async( ceremony, level ) ) if ( pairing_result.status != DevicePairingResultStatus.PROTECTION_LEVEL_COULD_NOT_BE_MET ): break logger.debug("Protection level %r not met. Retrying.", level) else: pairing_result = await custom_pairing.pair_async(ceremony) except Exception as e: raise BleakError("Failure trying to pair with device!") from e finally: custom_pairing.remove_pairing_requested(pairing_requested_token) if pairing_result.status not in ( DevicePairingResultStatus.PAIRED, DevicePairingResultStatus.ALREADY_PAIRED, ): raise BleakError( f"Could not pair with device: {pairing_result.status.name}" ) if logger.isEnabledFor(logging.DEBUG): # pairing_result.protection_level_used doesn't seem to return # accurate information if we don't update the DeviceInformation # first. device_information = await DeviceInformation.create_from_id_async( self._requester.device_information.id ) logger.debug( "Paired to device with protection level %s.", pairing_result.protection_level_used.name, )
[docs] @override async def unpair(self) -> None: """Attempts to unpair from the device. N.B. unpairing also leads to disconnection in the Windows backend. """ device = await self._create_requester( self._device_info if self._device_info is not None else _address_to_int(self.address) ) try: unpairing_result = await device.device_information.pairing.unpair_async() if unpairing_result.status not in ( DeviceUnpairingResultStatus.UNPAIRED, DeviceUnpairingResultStatus.ALREADY_UNPAIRED, ): raise BleakError( f"Could not unpair with device: {unpairing_result.status}" ) logger.info("Unpaired with device.") finally: device.close()
# GATT services methods async def _get_services( self, *, service_cache_mode: Optional[BluetoothCacheMode] = None, cache_mode: Optional[BluetoothCacheMode] = None, **kwargs: Any, ) -> BleakGATTServiceCollection: """Get all services registered for this GATT server. Returns: A :py:class:`bleak.backends.service.BleakGATTServiceCollection` with this device's services tree. """ # Return the Service Collection. if self.services is not None: return self.services logger.debug( "getting services (service_cache_mode=%r, cache_mode=%r)...", service_cache_mode, cache_mode, ) new_services = BleakGATTServiceCollection() services: Sequence[GattDeviceService] assert self._requester if self._requested_services is None: if service_cache_mode is not None: result = await FutureLike( self._requester.get_gatt_services_with_cache_mode_async( service_cache_mode ) ) else: result = await FutureLike(self._requester.get_gatt_services_async()) services = _ensure_success( result, "services", "Could not get GATT services", ) else: services = [] # REVISIT: should properly dispose services on cancel or protect from cancellation for s in self._requested_services: if service_cache_mode is not None: result = await FutureLike( self._requester.get_gatt_services_for_uuid_with_cache_mode_async( s, service_cache_mode ) ) else: result = await FutureLike( self._requester.get_gatt_services_for_uuid_async(s) ) services.extend( _ensure_success( result, "services", "Could not get GATT services", ) ) try: for service in services: if cache_mode is not None: result = await FutureLike( service.get_characteristics_with_cache_mode_async(cache_mode) ) else: result = await FutureLike(service.get_characteristics_async()) if result.status == GattCommunicationStatus.ACCESS_DENIED: # Windows does not allow access to services "owned" by the # OS. This includes services like HID and Bond Manager. logger.debug( "skipping service %s due to access denied", service.uuid ) continue characteristics: Sequence[GattCharacteristic] = _ensure_success( result, "characteristics", f"Could not get GATT characteristics for service {service.uuid} ({service.attribute_handle})", ) serv = BleakGATTService( service, service.attribute_handle, str(service.uuid) ) new_services.add_service(serv) for characteristic in characteristics: if cache_mode is not None: result = await FutureLike( characteristic.get_descriptors_with_cache_mode_async( cache_mode ) ) else: result = await FutureLike( characteristic.get_descriptors_async() ) descriptors: Sequence[GattDescriptor] = _ensure_success( result, "descriptors", f"Could not get GATT descriptors for characteristic {characteristic.uuid} ({characteristic.attribute_handle})", ) char = BleakGATTCharacteristic( characteristic, characteristic.attribute_handle, str(characteristic.uuid), list( gatt_char_props_to_strs( characteristic.characteristic_properties ) ), lambda: self._session.max_pdu_size - 3, serv, ) new_services.add_characteristic(char) for descriptor in descriptors: desc = BleakGATTDescriptor( descriptor, descriptor.attribute_handle, str(descriptor.uuid), char, ) new_services.add_descriptor(desc) return new_services except BaseException: # Don't leak services. WinRT is quite particular about services # being closed. logger.debug("disposing service objects") # HACK: sometimes GattDeviceService.Close() hangs forever, so we # add a delay to give the Windows Bluetooth stack some time to # "settle" before closing the services await asyncio.sleep(0.1) for service in services: service.close() raise # I/O methods
[docs] @override async def read_gatt_char( self, characteristic: BleakGATTCharacteristic, **kwargs: Any ) -> bytearray: """Perform read operation on the specified GATT characteristic. Args: characteristic (BleakGATTCharacteristic): The characteristic to read from. Keyword Args: use_cached (bool): ``False`` forces Windows to read the value from the device again and not use its own cached value. Defaults to ``False``. Returns: (bytearray) The read data. """ if not self.is_connected: raise BleakError("Not connected") assert self.services use_cached = kwargs.get("use_cached", False) gatt_char = cast(GattCharacteristic, characteristic.obj) value = bytearray( _ensure_success( await gatt_char.read_value_with_cache_mode_async( BluetoothCacheMode.CACHED if use_cached else BluetoothCacheMode.UNCACHED ), "value", f"Could not read characteristic handle {characteristic.handle}", ) ) logger.debug("Read Characteristic %04X : %s", characteristic.handle, value) return value
[docs] @override async def read_gatt_descriptor( self, descriptor: BleakGATTDescriptor, **kwargs: Any ) -> bytearray: """Perform read operation on the specified GATT descriptor. Args: descriptor: The descriptor to read from. Keyword Args: use_cached (bool): `False` forces Windows to read the value from the device again and not use its own cached value. Defaults to `False`. Returns: The read data. """ if not self.is_connected: raise BleakError("Not connected") assert self.services use_cached = kwargs.get("use_cached", False) gatt_desc = cast(GattDescriptor, descriptor.obj) value = bytearray( _ensure_success( await gatt_desc.read_value_with_cache_mode_async( BluetoothCacheMode.CACHED if use_cached else BluetoothCacheMode.UNCACHED ), "value", f"Could not read Descriptor value for {descriptor.handle:04X}", ) ) logger.debug("Read Descriptor %04X : %s", descriptor.handle, value) return value
[docs] @override async def write_gatt_char( self, characteristic: BleakGATTCharacteristic, data: Buffer, response: bool ) -> None: if not self.is_connected: raise BleakError("Not connected") buf = WinBuffer(len(data)) buf.length = buf.capacity with memoryview(buf) as mv: mv[:] = data gatt_char = cast(GattCharacteristic, characteristic.obj) _ensure_success( await gatt_char.write_value_with_result_and_option_async( buf, ( GattWriteOption.WRITE_WITH_RESPONSE if response else GattWriteOption.WRITE_WITHOUT_RESPONSE ), ), None, f"Could not write value {data} to characteristic {characteristic.handle:04X}", )
[docs] @override async def write_gatt_descriptor( self, descriptor: BleakGATTDescriptor, data: Buffer ) -> None: """Perform a write operation on the specified GATT descriptor. Args: descriptor: The descriptor to read from. data: The data to send (any bytes-like object). """ if not self.is_connected: raise BleakError("Not connected") assert self.services buf = WinBuffer(len(data)) buf.length = buf.capacity with memoryview(buf) as mv: mv[:] = data gatt_desc = cast(GattDescriptor, descriptor.obj) _ensure_success( await gatt_desc.write_value_with_result_async(buf), None, f"Could not write value {data!r} to descriptor {descriptor.handle:04X}", ) logger.debug("Write Descriptor %04X : %s", descriptor.handle, data)
[docs] @override async def start_notify( self, characteristic: BleakGATTCharacteristic, callback: NotifyCallback, **kwargs: Any, ) -> None: """ Activate notifications/indications on a characteristic. Keyword Args: force_indicate (bool): If this is set to True, then Bleak will set up a indication request instead of a notification request, given that the characteristic supports notifications as well as indications. """ winrt_char = cast(GattCharacteristic, characteristic.obj) # If we want to force indicate even when notify is available, also check if the device # actually supports indicate as well. if not kwargs.get("force_indicate", False) and ( winrt_char.characteristic_properties & GattCharacteristicProperties.NOTIFY ): cccd = GattClientCharacteristicConfigurationDescriptorValue.NOTIFY elif ( winrt_char.characteristic_properties & GattCharacteristicProperties.INDICATE ): cccd = GattClientCharacteristicConfigurationDescriptorValue.INDICATE else: raise BleakError( "characteristic does not support notifications or indications" ) loop = asyncio.get_running_loop() def handle_value_changed( sender: GattCharacteristic, args: GattValueChangedEventArgs ) -> None: value = bytearray(args.characteristic_value) loop.call_soon_threadsafe(callback, value) event_handler_token = winrt_char.add_value_changed(handle_value_changed) self._notification_callbacks[characteristic.handle] = event_handler_token try: _ensure_success( await winrt_char.write_client_characteristic_configuration_descriptor_with_result_async( cccd ), None, f"Could not start notify on {characteristic.handle:04X}", ) except BaseException: # This usually happens when a device reports that it supports indicate, # but it actually doesn't. if characteristic.handle in self._notification_callbacks: event_handler_token = self._notification_callbacks.pop( characteristic.handle ) winrt_char.remove_value_changed(event_handler_token) raise
[docs] @override async def stop_notify(self, characteristic: BleakGATTCharacteristic) -> None: """Deactivate notification/indication on a specified characteristic. Args: characteristic (BleakGATTCharacteristic): The characteristic to deactivate notification/indication on. """ if not self.is_connected: raise BleakError("Not connected") assert self.services gatt_char = cast(GattCharacteristic, characteristic.obj) _ensure_success( await gatt_char.write_client_characteristic_configuration_descriptor_with_result_async( GattClientCharacteristicConfigurationDescriptorValue.NONE ), None, f"Could not stop notify on {characteristic.handle:04X}", ) event_handler_token = self._notification_callbacks.pop(characteristic.handle) gatt_char.remove_value_changed(event_handler_token)
T = TypeVar("T")
[docs] class FutureLike(Generic[T]): """ Wraps a WinRT IAsyncOperation in a "future-like" object so that it can be passed to Python APIs. Needed until https://github.com/pywinrt/pywinrt/issues/14 """ _asyncio_future_blocking = False def __init__(self: Self, op: IAsyncOperation[T]) -> None: self._op = op self._callbacks: list[Callable[[Self], None]] = [] self._loop = asyncio.get_running_loop() self._cancel_requested = False self._result = None def call_callbacks() -> None: for c in self._callbacks: c(self) def call_callbacks_threadsafe( op: IAsyncOperation[T], status: AsyncStatus ) -> None: if status == AsyncStatus.COMPLETED: # have to get result on this thread, otherwise it may not return correct value self._result = op.get_results() self._loop.call_soon_threadsafe(call_callbacks) op.completed = call_callbacks_threadsafe
[docs] def result(self) -> T: if self._op.status == AsyncStatus.STARTED: raise asyncio.InvalidStateError if self._op.status == AsyncStatus.COMPLETED: if self._cancel_requested: raise asyncio.CancelledError assert self._result return self._result if self._op.status == AsyncStatus.CANCELED: raise asyncio.CancelledError if self._op.status == AsyncStatus.ERROR: if self._cancel_requested: raise asyncio.CancelledError error_code = self._op.error_code.value raise WinError(error_code) assert_never(self._op.status)
[docs] def done(self) -> bool: return self._op.status != AsyncStatus.STARTED
[docs] def cancelled(self) -> bool: return self._cancel_requested or self._op.status == AsyncStatus.CANCELED
[docs] def add_done_callback( self, callback: Callable[[Self], None], *, context: Optional[Context] = None, ) -> None: self._callbacks.append(callback)
[docs] def remove_done_callback(self, callback: Callable[[Self], None]) -> None: self._callbacks.remove(callback)
[docs] def cancel(self, msg: Optional[str] = None) -> bool: if self._cancel_requested or self._op.status != AsyncStatus.STARTED: return False self._cancel_requested = True self._op.cancel() return True
[docs] def exception(self) -> Optional[Exception]: if self._op.status == AsyncStatus.STARTED: raise asyncio.InvalidStateError if self._op.status == AsyncStatus.COMPLETED: if self._cancel_requested: raise asyncio.CancelledError return None if self._op.status == AsyncStatus.CANCELED: raise asyncio.CancelledError if self._op.status == AsyncStatus.ERROR: if self._cancel_requested: raise asyncio.CancelledError error_code = self._op.error_code.value return WinError(error_code) assert_never(self._op.status)
[docs] def get_loop(self) -> asyncio.AbstractEventLoop: return self._loop
def __await__(self): if not self.done(): self._asyncio_future_blocking = True yield self # This tells Task to wait for completion. if not self.done(): raise RuntimeError("await wasn't used with future") return self.result() # May raise too.