Method decodeFrame

src/components/cansignaldecoder/cansignaldecoder_p.cpp:75–153

}

void CanSignalDecoderPrivate::decodeFrame(const QCanBusFrame& frame, Direction const direction, bool)
{
    bool littleEndian;

    const CANmessages_t::value_type* msgDesc = nullptr;
    if (_db.getDb().count(frame.frameId()) > 0) {
        auto iter = _db.getDb().find(frame.frameId());

        if (iter != _db.getDb().end()) {
            msgDesc = &(*iter);
        }
    }

    if (msgDesc) {
        for (auto& sig : msgDesc->second) {

            switch (sig.byteOrder) {
            case 0:
                // Big endian
                littleEndian = false;
                break;
            case 1:
                // Little endian
                littleEndian = true;
                break;

            default:
                cds_error("byte order {} not suppoerted", sig.byteOrder);
                continue;
            }

            // Calculate how many bits are used already before this signal. Calculations are different for
            // little and big endian. Good overview on how big endian signals are aligned can be found
            // here: https://github.com/eerimoq/cantools#the-dump-subcommand
            uint8_t bitsBefore = 0;

            if (littleEndian) {
                bitsBefore = sig.startBit;
            } else {
                bitsBefore = beTransTable[sig.startBit];
            }

            if (bitsBefore + sig.signalSize > (frame.payload().size() * 8)) {
                cds_error(
                    "Invalid message size - startBit {}, sigSize {}, bitsBefore {}, payload size {}, littleEndian: {}",
                    sig.startBit, sig.signalSize, bitsBefore, frame.payload().size(), littleEndian);
                continue;
            }

            int64_t value = rawToSignal((const uint8_t*)frame.payload().constData(), sig.startBit, sig.signalSize,
                littleEndian, sig.valueSigned);

            QVariant sigVal;

            if ((std::fmod(sig.factor, 1) == 0.0) && (std::fmod(sig.offset, 1) == 0.0)) {
                // resulting number will be integer
                value = value * sig.factor + sig.offset;
                sigVal.setValue(value);