src/controller/python/chip/ble/library_handle.py

#
#    Copyright (c) 2021 Project CHIP Authors
#
#    Licensed under the Apache License, Version 2.0 (the "License");
#    you may not use this file except in compliance with the License.
#    You may obtain a copy of the License at
#
#        http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS,
#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#    See the License for the specific language governing permissions and
#    limitations under the License.
#

import ctypes
from ctypes import c_bool, c_char_p, c_uint32, c_void_p, py_object

import chip.native
from chip.ble.types import DeviceScannedCallback, ScanDoneCallback, ScanErrorCallback


# This prevents python auto-casting c_void_p to integers and
# auto-casting 32/64 bit values to int/long respectively. Without this
# passing in c_void_p does not see to work well for numbers
# in [0x80000000; 0xFFFFFFFF] (argument will be auto-cast to 64-bit negative)
class VoidPointer(c_void_p):
    pass


def _GetBleLibraryHandle() -> ctypes.CDLL:
    """ Get the native library handle with BLE method initialization.

      Retreives the CHIP native library handle and attaches signatures to
      native methods.
      """

    handle = chip.native.GetLibraryHandle()

    # Uses one of the type decorators as an indicator for everything being
    # initialized. Native methods default to c_int return types
    if handle.pychip_ble_adapter_list_new.restype != VoidPointer:
        setter = chip.native.NativeLibraryHandleMethodArguments(handle)

        setter.Set('pychip_ble_adapter_list_new', VoidPointer, [])
        setter.Set('pychip_ble_adapter_list_next', c_bool, [VoidPointer])
        setter.Set('pychip_ble_adapter_list_get_index',
                   c_uint32, [VoidPointer])
        setter.Set('pychip_ble_adapter_list_get_address',
                   c_char_p, [VoidPointer])
        setter.Set('pychip_ble_adapter_list_get_alias',
                   c_char_p, [VoidPointer])
        setter.Set('pychip_ble_adapter_list_get_name', c_char_p, [VoidPointer])
        setter.Set('pychip_ble_adapter_list_is_powered', c_bool, [VoidPointer])
        setter.Set('pychip_ble_adapter_list_delete', None, [VoidPointer])
        setter.Set('pychip_ble_adapter_list_get_raw_adapter',
                   VoidPointer, [VoidPointer])

        setter.Set('pychip_ble_start_scanning', VoidPointer, [
            py_object, VoidPointer, c_uint32, DeviceScannedCallback, ScanDoneCallback, ScanErrorCallback
        ])

    return handle