logiops/src/logid/InputDevice.cpp

/*
 * Copyright 2019-2020 PixlOne
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include <system_error>
#include <utility>

#include "InputDevice.h"

extern "C"
{
#include <libevdev/libevdev.h>
#include <libevdev/libevdev-uinput.h>
};

using namespace logid;

InputDevice::InvalidEventCode::InvalidEventCode(std::string name)
{
    _what = "Invalid event code " + name;
}

const char* InputDevice::InvalidEventCode::what() const noexcept
{
    return _what.c_str();
}

InputDevice::InputDevice(const char* name)
{
    device = libevdev_new();
    libevdev_set_name(device, name);

    ///TODO: Is it really a good idea to enable all events?
    libevdev_enable_event_type(device, EV_KEY);
    for(int i = 0; i < KEY_CNT; i++)
        libevdev_enable_event_code(device, EV_KEY, i, nullptr);
    libevdev_enable_event_type(device, EV_REL);
    for(int i = 0; i < REL_CNT; i++)
        libevdev_enable_event_code(device, EV_REL, i, nullptr);

    int err = libevdev_uinput_create_from_device(device,
            LIBEVDEV_UINPUT_OPEN_MANAGED, &ui_device);

    if(err != 0)
        throw std::system_error(-err, std::generic_category());
}

InputDevice::~InputDevice()
{
    libevdev_uinput_destroy(ui_device);
    libevdev_free(device);
}

void InputDevice::moveAxis(uint axis, int movement)
{
    _sendEvent(EV_REL, axis, movement);
}

void InputDevice::pressKey(uint code)
{
    _sendEvent(EV_KEY, code, 1);
}

void InputDevice::releaseKey(uint code)
{
    _sendEvent(EV_KEY, code, 0);
}

uint InputDevice::toKeyCode(std::string name)
{
    return _toEventCode(EV_KEY, std::move(name));
}

uint InputDevice::toAxisCode(std::string name)
{
    return _toEventCode(EV_KEY, std::move(name));
}

uint InputDevice::_toEventCode(uint type, const std::string& name)
{
    int code = libevdev_event_code_from_name(type, name.c_str());

    if(code == -1)
        throw InvalidEventCode(name);

    return code;
}

void InputDevice::_sendEvent(uint type, uint code, int value)
{
    libevdev_uinput_write_event(ui_device, type, code, value);
    libevdev_uinput_write_event(ui_device, EV_SYN, SYN_REPORT, 0);
}