mbed-os/features/FEATURE_BLE/source/DiscoveredCharacteristic.cpp

/* mbed Microcontroller Library
 * Copyright (c) 2006-2013 ARM Limited
 *
 * 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.
 */

#include "ble/DiscoveredCharacteristic.h"
#include "ble/GattClient.h"

ble_error_t
DiscoveredCharacteristic::read(uint16_t offset) const
{
    if (!props.read()) {
        return BLE_ERROR_OPERATION_NOT_PERMITTED;
    }

    if (!gattc) {
        return BLE_ERROR_INVALID_STATE;
    }

    return gattc->read(connHandle, valueHandle, offset);
}

struct OneShotReadCallback {
    static void launch(GattClient* client, Gap::Handle_t connHandle,
                       GattAttribute::Handle_t handle, const GattClient::ReadCallback_t& cb) {
        OneShotReadCallback* oneShot = new OneShotReadCallback(client, connHandle, handle, cb);
        oneShot->attach();
        // delete will be made when this callback is called
    }

private:
    OneShotReadCallback(GattClient* client, Gap::Handle_t connHandle,
                        GattAttribute::Handle_t handle, const GattClient::ReadCallback_t& cb) :
        _client(client),
        _connHandle(connHandle),
        _handle(handle),
        _callback(cb) { }

    void attach() {
        _client->onDataRead(makeFunctionPointer(this, &OneShotReadCallback::call));
    }

    void call(const GattReadCallbackParams* params) {
        // verifiy that it is the right characteristic on the right connection
        if (params->connHandle == _connHandle && params->handle == _handle) {
            _callback(params);
            _client->onDataRead().detach(makeFunctionPointer(this, &OneShotReadCallback::call));
            delete this;
        }
    }

    GattClient* _client;
    Gap::Handle_t _connHandle;
    GattAttribute::Handle_t _handle;
    GattClient::ReadCallback_t _callback;
};

ble_error_t DiscoveredCharacteristic::read(uint16_t offset, const GattClient::ReadCallback_t& onRead) const {
    ble_error_t error = read(offset);
    if (error) {
        return error;
    }

    OneShotReadCallback::launch(gattc, connHandle, valueHandle, onRead);

    return error;
}

ble_error_t
DiscoveredCharacteristic::write(uint16_t length, const uint8_t *value) const
{
    if (!props.write()) {
        return BLE_ERROR_OPERATION_NOT_PERMITTED;
    }

    if (!gattc) {
        return BLE_ERROR_INVALID_STATE;
    }

    return gattc->write(GattClient::GATT_OP_WRITE_REQ, connHandle, valueHandle, length, value);
}

ble_error_t
DiscoveredCharacteristic::writeWoResponse(uint16_t length, const uint8_t *value) const
{
    if (!props.writeWoResp()) {
        return BLE_ERROR_OPERATION_NOT_PERMITTED;
    }

    if (!gattc) {
        return BLE_ERROR_INVALID_STATE;
    }

    return gattc->write(GattClient::GATT_OP_WRITE_CMD, connHandle, valueHandle, length, value);
}

struct OneShotWriteCallback {
    static void launch(GattClient* client, Gap::Handle_t connHandle,
                       GattAttribute::Handle_t handle, const GattClient::WriteCallback_t& cb) {
        OneShotWriteCallback* oneShot = new OneShotWriteCallback(client, connHandle, handle, cb);
        oneShot->attach();
        // delete will be made when this callback is called
    }

private:
    OneShotWriteCallback(GattClient* client, Gap::Handle_t connHandle,
                        GattAttribute::Handle_t handle, const GattClient::WriteCallback_t& cb) :
        _client(client),
        _connHandle(connHandle),
        _handle(handle),
        _callback(cb) { }

    void attach() {
        _client->onDataWritten(makeFunctionPointer(this, &OneShotWriteCallback::call));
    }

    void call(const GattWriteCallbackParams* params) {
        // verifiy that it is the right characteristic on the right connection
        if (params->connHandle == _connHandle && params->handle == _handle) {
            _callback(params);
            _client->onDataWritten().detach(makeFunctionPointer(this, &OneShotWriteCallback::call));
            delete this;
        }
    }

    GattClient* _client;
    Gap::Handle_t _connHandle;
    GattAttribute::Handle_t _handle;
    GattClient::WriteCallback_t _callback;
};

ble_error_t DiscoveredCharacteristic::write(uint16_t length, const uint8_t *value, const GattClient::WriteCallback_t& onRead) const {
    ble_error_t error = write(length, value);
    if (error) {
        return error;
    }

    OneShotWriteCallback::launch(gattc, connHandle, valueHandle, onRead);

    return error;
}

ble_error_t DiscoveredCharacteristic::discoverDescriptors(
    const CharacteristicDescriptorDiscovery::DiscoveryCallback_t& onCharacteristicDiscovered, 
    const CharacteristicDescriptorDiscovery::TerminationCallback_t& onTermination) const {

    if(!gattc) {
        return BLE_ERROR_INVALID_STATE;
    }

    ble_error_t err = gattc->discoverCharacteristicDescriptors(
        *this, onCharacteristicDiscovered, onTermination
    );

    return err;
}