Function keepFileDescriptor

src/SFML/Window/DRM/InputImpl.cpp:109–135

Only keep fileDescriptors that we think are a keyboard, mouse or touchpad/touchscreen Joysticks are handled in /src/SFML/Window/Unix/JoystickImpl.cpp

// Only keep fileDescriptors that we think are a keyboard, mouse or touchpad/touchscreen
// Joysticks are handled in /src/SFML/Window/Unix/JoystickImpl.cpp
bool keepFileDescriptor(int fileDesc)
{
    std::array<unsigned long, NBITS(EV_MAX)>  bitmaskEv{};
    std::array<unsigned long, NBITS(KEY_MAX)> bitmaskKey{};
    std::array<unsigned long, NBITS(ABS_MAX)> bitmaskAbs{};
    std::array<unsigned long, NBITS(REL_MAX)> bitmaskRel{};

    ioctl(fileDesc, EVIOCGBIT(0, sizeof(bitmaskEv)), bitmaskEv.data());
    ioctl(fileDesc, EVIOCGBIT(EV_KEY, sizeof(bitmaskKey)), bitmaskKey.data());
    ioctl(fileDesc, EVIOCGBIT(EV_ABS, sizeof(bitmaskAbs)), bitmaskAbs.data());
    ioctl(fileDesc, EVIOCGBIT(EV_REL, sizeof(bitmaskRel)), bitmaskRel.data());

    // This is the keyboard test used by SDL.
    // The first 32 bits are ESC, numbers and Q to D;  If we have any of those,
    // consider it a keyboard device; do not test for KEY_RESERVED, though
    const bool isKeyboard = (bitmaskKey[0] & 0xFFFFFFFE);

    const bool isAbs = TEST_BIT(EV_ABS, bitmaskEv) && TEST_BIT(ABS_X, bitmaskAbs) && TEST_BIT(ABS_Y, bitmaskAbs);

    const bool isRel = TEST_BIT(EV_REL, bitmaskEv) && TEST_BIT(REL_X, bitmaskRel) && TEST_BIT(REL_Y, bitmaskRel);

    const bool isMouse = (isAbs || isRel) && TEST_BIT(BTN_MOUSE, bitmaskKey);

    const bool isTouch = isAbs && (TEST_BIT(BTN_TOOL_FINGER, bitmaskKey) || TEST_BIT(BTN_TOUCH, bitmaskKey));

    return isKeyboard || isMouse || isTouch;
}

void initFileDescriptors()
{