QObject::connect(serialPort, &QSerialPort::readyRead,

                         this, &DataFormatPanel::onDataReady);

    }

    emit skipByteEnabledChanged(skipByteEnabled());

}

bool DataFormatPanel::skipByteEnabled()

{

    return numberFormat != NumberFormat_ASCII;

}

unsigned DataFormatPanel::numOfChannels()

{

    return _numOfChannels;

}

void DataFormatPanel::onNumOfChannelsSP(int value)

{

    _numOfChannels = value;

    emit numOfChannelsChanged(value);

}

void DataFormatPanel::requestSkipByte()

{

    skipByteRequested = true;

}

void DataFormatPanel::pause(bool enabled)

{

    paused = enabled;

}

void DataFormatPanel::enableDemo(bool enabled)

{

    if (enabled)

    {

        demoTimer.start();

    }

    else

    {

        demoTimer.stop();

    }

}

void DataFormatPanel::spsTimerTimeout()

{

    unsigned currentSps = _samplesPerSecond;

    if (currentSps != _samplesPerSecond)

    {

        emit samplesPerSecondChanged(_samplesPerSecond);

    }

    sampleCount = 0;

}

void DataFormatPanel::demoTimerTimeout()

{

    const double period = 100;

    demoCount++;

    if (demoCount >= 100) demoCount = 0;

    if (!paused)

    {

        for (unsigned ci = 0; ci < _numOfChannels; ci++)

        {

            // we are calculating the fourier components of square wave

            double value = 4*sin(2*M_PI*double((ci+1)*demoCount)/period)/((2*(ci+1))*M_PI);

            addChannelData(ci, &value, 1);

        }

        emit dataAdded();

    }

}

void DataFormatPanel::onDataReady()

{

    // a package is a set of channel data like {CHAN0_SAMPLE, CHAN1_SAMPLE...}

    int packageSize = sampleSize * _numOfChannels;

    int bytesAvailable = serialPort->bytesAvailable();

    int numOfPackagesToRead =

        (bytesAvailable - (bytesAvailable % packageSize)) / packageSize;

    if (paused)

    {

        // read and discard data

        serialPort->read(numOfPackagesToRead*packageSize);

        return;

    }

    if (bytesAvailable > 0 && skipByteRequested)

    {

        serialPort->read(1);

        skipByteRequested = false;

        bytesAvailable--;

    }

    unsigned numOfChannels = dataFormatPanel.numOfChannels();

    QObject::connect(&dataFormatPanel,

                     &DataFormatPanel::numOfChannelsChanged,

                     this,

                     &MainWindow::onNumOfChannelsChanged);

    // init channel data and curve list

    for (unsigned int i = 0; i < numOfChannels; i++)

    {

        channelBuffers.append(new FrameBuffer(numOfSamples));

        curves.append(new QwtPlotCurve(QString("Channel %1").arg(i+1)));

        curves[i]->setSamples(channelBuffers[i]);

        curves[i]->setPen(Plot::makeColor(i));

        curves[i]->attach(ui->plot);

    }

    // init auto scale

    ui->plot->setAxis(ui->cbAutoScale->isChecked(),

                      ui->spYmin->value(), ui->spYmax->value());

    // init scale range preset list

    for (int nbits = 8; nbits <= 24; nbits++) // signed binary formats

    {

        int rmax = pow(2, nbits-1)-1;

        int rmin = -rmax-1;

        Range r = {double(rmin),  double(rmax)};

        ui->cbRangePresets->addItem(

            QString().sprintf("Signed %d bits %d to +%d", nbits, rmin, rmax),

            QVariant::fromValue(r));

    }

    for (int nbits = 8; nbits <= 24; nbits++) // unsigned binary formats

    {

        int rmax = pow(2, nbits)-1;

        ui->cbRangePresets->addItem(

            QString().sprintf("Unsigned %d bits %d to +%d", nbits, 0, rmax),

            QVariant::fromValue(Range{0, double(rmax)}));

    }

    ui->cbRangePresets->addItem("-1 to +1", QVariant::fromValue(Range{-1, +1}));

    ui->cbRangePresets->addItem("0 to +1", QVariant::fromValue(Range{0, +1}));

    ui->cbRangePresets->addItem("-100 to +100", QVariant::fromValue(Range{-100, +100}));

    ui->cbRangePresets->addItem("0 to +100", QVariant::fromValue(Range{0, +100}));

    QObject::connect(ui->cbRangePresets, SIGNAL(activated(int)),

                     this, SLOT(onRangeSelected()));

    // Init sps (sample per second) counter

    spsLabel.setText("0sps");

    ui->statusBar->addPermanentWidget(&spsLabel);

    QObject::connect(&dataFormatPanel,

                     &DataFormatPanel::samplesPerSecondChanged,

                     this, &MainWindow::onSpsChanged);

    // init demo

    QObject::connect(ui->actionDemoMode, &QAction::toggled,

                     this, &MainWindow::enableDemo);

    {   // init demo indicator

        QwtText demoText(" DEMO RUNNING ");  // looks better with spaces

        demoText.setColor(QColor("white"));

        demoText.setBackgroundBrush(Qt::darkRed);

        demoText.setBorderRadius(4);

        demoText.setRenderFlags(Qt::AlignLeft | Qt::AlignTop);

        demoIndicator.setText(demoText);

        demoIndicator.hide();

        demoIndicator.attach(ui->plot);

    }

}

MainWindow::~MainWindow()

{

    for (auto curve : curves)

    {

        // also deletes respective FrameBuffer

        delete curve;

    }

    if (serialPort.isOpen())

    {

        serialPort.close();

    }

    delete ui;

    ui = NULL; // we check if ui is deleted in messageHandler

}

void MainWindow::setupAboutDialog()

{

    Ui_AboutDialog uiAboutDialog;

    uiAboutDialog.setupUi(&aboutDialog);

    QObject::connect(uiAboutDialog.pbAboutQt, &QPushButton::clicked,

                     [](){ QApplication::aboutQt();});

    QString aboutText = uiAboutDialog.lbAbout->text();

    aboutText.replace("$VERSION_STRING$", VERSION_STRING);