# -*- coding: utf-8 -*-
"""
BLE Client for python-for-android
"""
import asyncio
import logging
import uuid
import warnings
from typing import Optional, Set, Union
from android.broadcast import BroadcastReceiver
from jnius import java_method
from ...exc import BleakError
from ..characteristic import BleakGATTCharacteristic
from ..client import BaseBleakClient, NotifyCallback
from ..device import BLEDevice
from ..service import BleakGATTServiceCollection
from . import defs, utils
from .characteristic import BleakGATTCharacteristicP4Android
from .descriptor import BleakGATTDescriptorP4Android
from .service import BleakGATTServiceP4Android
logger = logging.getLogger(__name__)
[docs]class BleakClientP4Android(BaseBleakClient):
"""A python-for-android Bleak Client
Args:
address_or_ble_device:
The Bluetooth address of the BLE peripheral to connect to or the
:class:`BLEDevice` object representing it.
services:
Optional set of services UUIDs to filter.
"""
def __init__(
self,
address_or_ble_device: Union[BLEDevice, str],
services: Optional[Set[uuid.UUID]],
**kwargs,
):
super(BleakClientP4Android, self).__init__(address_or_ble_device, **kwargs)
self._requested_services = (
set(map(defs.UUID.fromString, services)) if services else None
)
# kwarg "device" is for backwards compatibility
self.__adapter = kwargs.get("adapter", kwargs.get("device", None))
self.__gatt = None
self.__mtu = 23
def __del__(self):
if self.__gatt is not None:
self.__gatt.close()
self.__gatt = None
# Connectivity methods
[docs] async def connect(self, **kwargs) -> bool:
"""Connect to the specified GATT server.
Returns:
Boolean representing connection status.
"""
loop = asyncio.get_running_loop()
self.__adapter = defs.BluetoothAdapter.getDefaultAdapter()
if self.__adapter is None:
raise BleakError("Bluetooth is not supported on this hardware platform")
if self.__adapter.getState() != defs.BluetoothAdapter.STATE_ON:
raise BleakError("Bluetooth is not turned on")
self.__device = self.__adapter.getRemoteDevice(self.address)
self.__callbacks = _PythonBluetoothGattCallback(self, loop)
self._subscriptions = {}
logger.debug(f"Connecting to BLE device @ {self.address}")
(self.__gatt,) = await self.__callbacks.perform_and_wait(
dispatchApi=self.__device.connectGatt,
dispatchParams=(
defs.context,
False,
self.__callbacks.java,
defs.BluetoothDevice.TRANSPORT_LE,
),
resultApi="onConnectionStateChange",
resultExpected=(defs.BluetoothProfile.STATE_CONNECTED,),
return_indicates_status=False,
)
try:
logger.debug("Connection successful.")
# unlike other backends, Android doesn't automatically negotiate
# the MTU, so we request the largest size possible like BlueZ
logger.debug("requesting mtu...")
(self.__mtu,) = await self.__callbacks.perform_and_wait(
dispatchApi=self.__gatt.requestMtu,
dispatchParams=(517,),
resultApi="onMtuChanged",
)
logger.debug("discovering services...")
await self.__callbacks.perform_and_wait(
dispatchApi=self.__gatt.discoverServices,
dispatchParams=(),
resultApi="onServicesDiscovered",
)
await self.get_services()
except BaseException:
# if connecting is canceled or one of the above fails, we need to
# disconnect
try:
await self.disconnect()
except Exception:
pass
raise
return True
[docs] async def disconnect(self) -> bool:
"""Disconnect from the specified GATT server.
Returns:
Boolean representing if device is disconnected.
"""
logger.debug("Disconnecting from BLE device...")
if self.__gatt is None:
# No connection exists. Either one hasn't been created or
# we have already called disconnect and closed the gatt
# connection.
logger.debug("already disconnected")
return True
# Try to disconnect the actual device/peripheral
try:
await self.__callbacks.perform_and_wait(
dispatchApi=self.__gatt.disconnect,
dispatchParams=(),
resultApi="onConnectionStateChange",
resultExpected=(defs.BluetoothProfile.STATE_DISCONNECTED,),
unless_already=True,
return_indicates_status=False,
)
self.__gatt.close()
except Exception as e:
logger.error(f"Attempt to disconnect device failed: {e}")
self.__gatt = None
self.__callbacks = None
# Reset all stored services.
self.services = None
return True
[docs] async def pair(self, *args, **kwargs) -> bool:
"""Pair with the peripheral.
You can use ConnectDevice method if you already know the MAC address of the device.
Else you need to StartDiscovery, Trust, Pair and Connect in sequence.
Returns:
Boolean regarding success of pairing.
"""
loop = asyncio.get_running_loop()
bondedFuture = loop.create_future()
def handleBondStateChanged(context, intent):
bond_state = intent.getIntExtra(defs.BluetoothDevice.EXTRA_BOND_STATE, -1)
if bond_state == -1:
loop.call_soon_threadsafe(
bondedFuture.set_exception,
BleakError(f"Unexpected bond state {bond_state}"),
)
elif bond_state == defs.BluetoothDevice.BOND_NONE:
loop.call_soon_threadsafe(
bondedFuture.set_exception,
BleakError(
f"Device with address {self.address} could not be paired with."
),
)
elif bond_state == defs.BluetoothDevice.BOND_BONDED:
loop.call_soon_threadsafe(bondedFuture.set_result, True)
receiver = BroadcastReceiver(
handleBondStateChanged,
actions=[defs.BluetoothDevice.ACTION_BOND_STATE_CHANGED],
)
receiver.start()
try:
# See if it is already paired.
bond_state = self.__device.getBondState()
if bond_state == defs.BluetoothDevice.BOND_BONDED:
return True
elif bond_state == defs.BluetoothDevice.BOND_NONE:
logger.debug(f"Pairing to BLE device @ {self.address}")
if not self.__device.createBond():
raise BleakError(
f"Could not initiate bonding with device @ {self.address}"
)
return await bondedFuture
finally:
await receiver.stop()
[docs] async def unpair(self) -> bool:
"""Unpair with the peripheral.
Returns:
Boolean regarding success of unpairing.
"""
warnings.warn(
"Unpairing is seemingly unavailable in the Android API at the moment."
)
return False
@property
def is_connected(self) -> bool:
"""Check connection status between this client and the server.
Returns:
Boolean representing connection status.
"""
return (
self.__callbacks is not None
and self.__callbacks.states["onConnectionStateChange"][1]
== defs.BluetoothProfile.STATE_CONNECTED
)
@property
def mtu_size(self) -> Optional[int]:
return self.__mtu
# GATT services methods
[docs] async def get_services(self) -> BleakGATTServiceCollection:
"""Get all services registered for this GATT server.
Returns:
A :py:class:`bleak.backends.service.BleakGATTServiceCollection` with this device's services tree.
"""
if self.services is not None:
return self.services
services = BleakGATTServiceCollection()
logger.debug("Get Services...")
for java_service in self.__gatt.getServices():
if (
self._requested_services is not None
and java_service.getUuid() not in self._requested_services
):
continue
service = BleakGATTServiceP4Android(java_service)
services.add_service(service)
for java_characteristic in java_service.getCharacteristics():
characteristic = BleakGATTCharacteristicP4Android(
java_characteristic,
service.uuid,
service.handle,
self.__mtu - 3,
)
services.add_characteristic(characteristic)
for descriptor_index, java_descriptor in enumerate(
java_characteristic.getDescriptors()
):
descriptor = BleakGATTDescriptorP4Android(
java_descriptor,
characteristic.uuid,
characteristic.handle,
descriptor_index,
)
services.add_descriptor(descriptor)
self.services = services
return self.services
# IO methods
[docs] async def read_gatt_char(
self,
char_specifier: Union[BleakGATTCharacteristicP4Android, int, str, uuid.UUID],
**kwargs,
) -> bytearray:
"""Perform read operation on the specified GATT characteristic.
Args:
char_specifier (BleakGATTCharacteristicP4Android, int, str or UUID): The characteristic to read from,
specified by either integer handle, UUID or directly by the
BleakGATTCharacteristicP4Android object representing it.
Returns:
(bytearray) The read data.
"""
if not isinstance(char_specifier, BleakGATTCharacteristicP4Android):
characteristic = self.services.get_characteristic(char_specifier)
else:
characteristic = char_specifier
if not characteristic:
raise BleakError(
f"Characteristic with UUID {char_specifier} could not be found!"
)
(value,) = await self.__callbacks.perform_and_wait(
dispatchApi=self.__gatt.readCharacteristic,
dispatchParams=(characteristic.obj,),
resultApi=("onCharacteristicRead", characteristic.handle),
)
value = bytearray(value)
logger.debug(
f"Read Characteristic {characteristic.uuid} | {characteristic.handle}: {value}"
)
return value
[docs] async def read_gatt_descriptor(
self,
desc_specifier: Union[BleakGATTDescriptorP4Android, str, uuid.UUID],
**kwargs,
) -> bytearray:
"""Perform read operation on the specified GATT descriptor.
Args:
desc_specifier (BleakGATTDescriptorP4Android, str or UUID): The descriptor to read from,
specified by either UUID or directly by the
BleakGATTDescriptorP4Android object representing it.
Returns:
(bytearray) The read data.
"""
if not isinstance(desc_specifier, BleakGATTDescriptorP4Android):
descriptor = self.services.get_descriptor(desc_specifier)
else:
descriptor = desc_specifier
if not descriptor:
raise BleakError(f"Descriptor with UUID {desc_specifier} was not found!")
(value,) = await self.__callbacks.perform_and_wait(
dispatchApi=self.__gatt.readDescriptor,
dispatchParams=(descriptor.obj,),
resultApi=("onDescriptorRead", descriptor.uuid),
)
value = bytearray(value)
logger.debug(
f"Read Descriptor {descriptor.uuid} | {descriptor.handle}: {value}"
)
return value
[docs] async def write_gatt_char(
self,
characteristic: BleakGATTCharacteristic,
data: bytearray,
response: bool,
) -> None:
if response:
characteristic.obj.setWriteType(
defs.BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT
)
else:
characteristic.obj.setWriteType(
defs.BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE
)
characteristic.obj.setValue(data)
await self.__callbacks.perform_and_wait(
dispatchApi=self.__gatt.writeCharacteristic,
dispatchParams=(characteristic.obj,),
resultApi=("onCharacteristicWrite", characteristic.handle),
)
logger.debug(
f"Write Characteristic {characteristic.uuid} | {characteristic.handle}: {data}"
)
[docs] async def write_gatt_descriptor(
self,
desc_specifier: Union[BleakGATTDescriptorP4Android, str, uuid.UUID],
data: bytearray,
) -> None:
"""Perform a write operation on the specified GATT descriptor.
Args:
desc_specifier (BleakGATTDescriptorP4Android, str or UUID): The descriptor to write
to, specified by either UUID or directly by the
BleakGATTDescriptorP4Android object representing it.
data (bytes or bytearray): The data to send.
"""
if not isinstance(desc_specifier, BleakGATTDescriptorP4Android):
descriptor = self.services.get_descriptor(desc_specifier)
else:
descriptor = desc_specifier
if not descriptor:
raise BleakError(f"Descriptor {desc_specifier} was not found!")
descriptor.obj.setValue(data)
await self.__callbacks.perform_and_wait(
dispatchApi=self.__gatt.writeDescriptor,
dispatchParams=(descriptor.obj,),
resultApi=("onDescriptorWrite", descriptor.uuid),
)
logger.debug(
f"Write Descriptor {descriptor.uuid} | {descriptor.handle}: {data}"
)
[docs] async def start_notify(
self,
characteristic: BleakGATTCharacteristic,
callback: NotifyCallback,
**kwargs,
) -> None:
"""
Activate notifications/indications on a characteristic.
"""
self._subscriptions[characteristic.handle] = callback
assert self.__gatt is not None
if not self.__gatt.setCharacteristicNotification(characteristic.obj, True):
raise BleakError(
f"Failed to enable notification for characteristic {characteristic.uuid}"
)
await self.write_gatt_descriptor(
characteristic.notification_descriptor,
defs.BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE,
)
[docs] async def stop_notify(
self,
char_specifier: Union[BleakGATTCharacteristicP4Android, int, str, uuid.UUID],
) -> None:
"""Deactivate notification/indication on a specified characteristic.
Args:
char_specifier (BleakGATTCharacteristicP4Android, int, str or UUID): The characteristic to deactivate
notification/indication on, specified by either integer handle, UUID or
directly by the BleakGATTCharacteristicP4Android object representing it.
"""
if not isinstance(char_specifier, BleakGATTCharacteristicP4Android):
characteristic = self.services.get_characteristic(char_specifier)
else:
characteristic = char_specifier
if not characteristic:
raise BleakError(f"Characteristic {char_specifier} not found!")
await self.write_gatt_descriptor(
characteristic.notification_descriptor,
defs.BluetoothGattDescriptor.DISABLE_NOTIFICATION_VALUE,
)
if not self.__gatt.setCharacteristicNotification(characteristic.obj, False):
raise BleakError(
f"Failed to disable notification for characteristic {characteristic.uuid}"
)
del self._subscriptions[characteristic.handle]
class _PythonBluetoothGattCallback(utils.AsyncJavaCallbacks):
__javainterfaces__ = [
"com.github.hbldh.bleak.PythonBluetoothGattCallback$Interface"
]
def __init__(self, client, loop):
super().__init__(loop)
self._client = client
self.java = defs.PythonBluetoothGattCallback(self)
def result_state(self, status, resultApi, *data):
if status == defs.BluetoothGatt.GATT_SUCCESS:
failure_str = None
else:
failure_str = defs.GATT_STATUS_STRINGS.get(status, status)
self._loop.call_soon_threadsafe(
self._result_state_unthreadsafe, failure_str, resultApi, data
)
@java_method("(II)V")
def onConnectionStateChange(self, status, new_state):
try:
self.result_state(status, "onConnectionStateChange", new_state)
except BleakError:
pass
if (
new_state == defs.BluetoothProfile.STATE_DISCONNECTED
and self._client._disconnected_callback is not None
):
self._client._disconnected_callback()
@java_method("(II)V")
def onMtuChanged(self, mtu, status):
self.result_state(status, "onMtuChanged", mtu)
@java_method("(I)V")
def onServicesDiscovered(self, status):
self.result_state(status, "onServicesDiscovered")
@java_method("(I[B)V")
def onCharacteristicChanged(self, handle, value):
self._loop.call_soon_threadsafe(
self._client._subscriptions[handle], bytearray(value.tolist())
)
@java_method("(II[B)V")
def onCharacteristicRead(self, handle, status, value):
self.result_state(
status, ("onCharacteristicRead", handle), bytes(value.tolist())
)
@java_method("(II)V")
def onCharacteristicWrite(self, handle, status):
self.result_state(status, ("onCharacteristicWrite", handle))
@java_method("(Ljava/lang/String;I[B)V")
def onDescriptorRead(self, uuid, status, value):
self.result_state(status, ("onDescriptorRead", uuid), bytes(value.tolist()))
@java_method("(Ljava/lang/String;I)V")
def onDescriptorWrite(self, uuid, status):
self.result_state(status, ("onDescriptorWrite", uuid))