setupAboutDialog();

    // init UI signals

    // menu signals

    QObject::connect(ui->actionHelpAbout, &QAction::triggered,

              &aboutDialog, &QWidget::show);

    QObject::connect(ui->actionExportCsv, &QAction::triggered,

                     this, &MainWindow::onExportCsv);

    QObject::connect(ui->actionQuit, &QAction::triggered,

                     this, &MainWindow::close);

    QObject::connect(&portControl, &PortControl::portToggled,

                     this, &MainWindow::onPortToggled);

    QObject::connect(&portControl, &PortControl::skipByteRequested,

                     this, &MainWindow::skipByte);

    QObject::connect(ui->spNumOfSamples, SELECT<int>::OVERLOAD_OF(&QSpinBox::valueChanged),

                     this, &MainWindow::onNumOfSamplesChanged);

    QObject::connect(ui->cbAutoScale, &QCheckBox::toggled,

                     this, &MainWindow::onAutoScaleChecked);

    QObject::connect(ui->spYmin, SIGNAL(valueChanged(double)),

                     this, SLOT(onYScaleChanged()));

    QObject::connect(ui->spYmax, SIGNAL(valueChanged(double)),

                     this, SLOT(onYScaleChanged()));

    QObject::connect(ui->actionClear, SIGNAL(triggered(bool)),

                     this, SLOT(clearPlot()));

    // setup number of channels spinbox

    QObject::connect(ui->spNumOfChannels,

                     SELECT<int>::OVERLOAD_OF(&QSpinBox::valueChanged),

                     this, &MainWindow::onNumOfChannelsChanged);

    // setup number format buttons

    numberFormatButtons.addButton(ui->rbUint8,  NumberFormat_uint8);

    numberFormatButtons.addButton(ui->rbUint16, NumberFormat_uint16);

    numberFormatButtons.addButton(ui->rbUint32, NumberFormat_uint32);

    numberFormatButtons.addButton(ui->rbInt8,   NumberFormat_int8);

    numberFormatButtons.addButton(ui->rbInt16,  NumberFormat_int16);

    numberFormatButtons.addButton(ui->rbInt32,  NumberFormat_int32);

    numberFormatButtons.addButton(ui->rbFloat,  NumberFormat_float);

    numberFormatButtons.addButton(ui->rbASCII,  NumberFormat_ASCII);

    QObject::connect(&numberFormatButtons, SIGNAL(buttonToggled(int, bool)),

                     this, SLOT(onNumberFormatButtonToggled(int, bool)));

    // init port signals

    QObject::connect(&(this->serialPort), SIGNAL(error(QSerialPort::SerialPortError)),

                     this, SLOT(onPortError(QSerialPort::SerialPortError)));

    // set limits for axis limit boxes

    ui->spYmin->setRange((-1) * std::numeric_limits<double>::max(),

                         std::numeric_limits<double>::max());

    ui->spYmax->setRange((-1) * std::numeric_limits<double>::max(),

                         std::numeric_limits<double>::max());

    // init data arrays and plot

    numOfSamples = ui->spNumOfSamples->value();

    numOfChannels = 1;

    dataX.resize(numOfSamples);

    for (int i = 0; i < dataX.size(); i++)

    {

        dataX[i] = i;

    }

    // init channel data and curve list

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

    {

        channelsData.append(DataArray(numOfSamples, 0.0));

        curves.append(new QwtPlotCurve());

        curves[i]->setSamples(dataX, channelsData[i]);

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

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

    }

    // init number format

    if (numberFormatButtons.checkedId() >= 0)

    {

        selectNumberFormat((NumberFormat) numberFormatButtons.checkedId());

    }

    else

    {

        selectNumberFormat(NumberFormat_uint8);

    }

    // init text view

    ui->ptTextView->setEnabled(ui->cbEnableTextView->isChecked());

    // TODO: does this work in binary mode? (no new lines)

    ui->ptTextView->setMaximumBlockCount(10000);

    QObject::connect(ui->cbEnableTextView, &QCheckBox::toggled,

                     ui->ptTextView, &QWidget::setEnabled);

    QObject::connect(ui->pbClearTextView, &QPushButton::clicked,

                     ui->ptTextView, &QPlainTextEdit::clear);

    // Init sps (sample per second) counter

    sampleCount = 0;

    spsLabel.setText("0sps");

    spsLabel.setToolTip("samples per second (total of all channels)");

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

    spsTimer.start(SPS_UPDATE_TIMEOUT * 1000);

    QObject::connect(&spsTimer, &QTimer::timeout,

                     this, &MainWindow::spsTimerTimeout);

    // Init demo mode

    demoCount = 0;

    demoTimer.setInterval(100);

    QObject::connect(&demoTimer, &QTimer::timeout,

                     this, &MainWindow::demoTimerTimeout);

    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)

    {

        delete curve;

    }

    if (serialPort.isOpen())

    {

        serialPort.close();

    }

    delete ui;

}

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);

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

    uiAboutDialog.lbAbout->setText(aboutText);

}

void MainWindow::onPortToggled(bool open)

{

    // make sure demo mode is disabled

    if (open && isDemoRunning()) enableDemo(false);

    ui->actionDemoMode->setEnabled(!open);

}

void MainWindow::onDataReady()

{

    if (!ui->actionPause->isChecked())

    {

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

        int packageSize = sampleSize * numOfChannels;

        int bytesAvailable = serialPort.bytesAvailable();

        if (bytesAvailable > 0 && skipByteRequested)

        {

            serialPort.read(1);

            skipByteRequested = false;

            bytesAvailable--;

        }

        if (bytesAvailable < packageSize)

        {

            return;

        }

        else

        {

            int numOfPackagesToRead =

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

            QVector<DataArray> channelSamples(numOfChannels);

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

            {

                channelSamples[ci].resize(numOfPackagesToRead);

            }

            int i = 0;

            while(i < numOfPackagesToRead)

        ui->lYmin->setEnabled(false);

        ui->lYmax->setEnabled(false);

        ui->spYmin->setEnabled(false);

        ui->spYmax->setEnabled(false);

    }

    else

    {

        ui->lYmin->setEnabled(true);

        ui->lYmax->setEnabled(true);

        ui->spYmin->setEnabled(true);

        ui->spYmax->setEnabled(true);

        ui->plot->setAxisScale(QwtPlot::yLeft, ui->spYmin->value(),

                               ui->spYmax->value());

    }

}

void MainWindow::onYScaleChanged()

{

    ui->plot->setAxisScale(QwtPlot::yLeft, ui->spYmin->value(),

                           ui->spYmax->value());

}

void MainWindow::onNumberFormatButtonToggled(int numberFormatId, bool checked)

{

    if (checked) selectNumberFormat((NumberFormat) numberFormatId);

}

void MainWindow::selectNumberFormat(NumberFormat numberFormatId)

{

    numberFormat = numberFormatId;

    switch(numberFormat)

    {

        case NumberFormat_uint8:

            sampleSize = 1;

            readSample = &MainWindow::readSampleAs<quint8>;

            break;

        case NumberFormat_int8:

            sampleSize = 1;

            readSample = &MainWindow::readSampleAs<qint8>;

            break;

        case NumberFormat_uint16:

            sampleSize = 2;

            readSample = &MainWindow::readSampleAs<quint16>;

            break;

        case NumberFormat_int16:

            sampleSize = 2;

            readSample = &MainWindow::readSampleAs<qint16>;

            break;

        case NumberFormat_uint32:

            sampleSize = 4;

            readSample = &MainWindow::readSampleAs<quint32>;

            break;

        case NumberFormat_int32:

            sampleSize = 4;

            readSample = &MainWindow::readSampleAs<qint32>;

            break;

        case NumberFormat_float:

            sampleSize = 4;

            readSample = &MainWindow::readSampleAs<float>;

            break;

        case NumberFormat_ASCII:

            sampleSize = 0;    // these two members should not be used

            readSample = NULL; // in this mode

            break;

    }

    if (numberFormat == NumberFormat_ASCII)

    {

        QObject::disconnect(&(this->serialPort), &QSerialPort::readyRead, 0, 0);

        QObject::connect(&(this->serialPort), &QSerialPort::readyRead,

                         this, &MainWindow::onDataReadyASCII);

        portControl.enableSkipByte();

    }

    else

    {

        QObject::disconnect(&(this->serialPort), &QSerialPort::readyRead, 0, 0);

        QObject::connect(&(this->serialPort), &QSerialPort::readyRead,

                         this, &MainWindow::onDataReady);

        portControl.enableSkipByte(false);

    }

}

template<typename T> double MainWindow::readSampleAs()

{

    T data;

    this->serialPort.read((char*) &data, sizeof(data));

    // print data in hex format

    if (ui->cbEnableTextView->isChecked())

    {

        QTextCursor cursor(ui->ptTextView->document());

        cursor.movePosition(QTextCursor::End);

        QByteArray ba((char*) &data, sizeof(data));

        cursor.insertText(ba.toHex() + " ");

    }

    if (ui->rbLittleE->isChecked())

    {

        data = qFromLittleEndian(data);

    }

    else

    {

        data = qFromBigEndian(data);

    }

    return double(data);

}

bool MainWindow::isDemoRunning()

{

    return ui->actionDemoMode->isChecked();

}

void MainWindow::spsTimerTimeout()

{

    spsLabel.setText(QString::number(sampleCount/SPS_UPDATE_TIMEOUT) + "sps");

    sampleCount = 0;

}

void MainWindow::demoTimerTimeout()

{

    demoCount++;

    if (demoCount > 100) demoCount = 0;

    if (!ui->actionPause->isChecked())

    {

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

        {

            DataArray data(1);

            data.replace(0, (ci + 1)*demoCount);

            addChannelData(ci, data);

        }

    }

}

void MainWindow::enableDemo(bool enabled)

{

    if (enabled)

    {

        if (!serialPort.isOpen())

        {

            demoTimer.start();

            ui->actionDemoMode->setChecked(true);

            demoIndicator.show();

            ui->plot->replot();

        }

        else

        {

            ui->actionDemoMode->setChecked(false);

        }

    }

    else

    {

        demoTimer.stop();

        ui->actionDemoMode->setChecked(false);

        demoIndicator.hide();

        ui->plot->replot();

    }

}

/*

  Below crude drawing demostrates how color selection occurs for

  given channel index

  0°                     <--Hue Value-->                           360°

  |* . o . + . o . * . o . + . o . * . o . + . o . * . o . + . o . |

  * -> 0-3

  + -> 4-7

  o -> 8-15

  . -> 16-31

 */

QColor MainWindow::makeColor(unsigned int channelIndex)

{

    auto i = channelIndex;

    if (i < 4)

    {

        return QColor::fromHsv(360*i/4, 255, 230);

    }

    else

    {

        double p = floor(log2(i));

        double n = pow(2, p);

        i = i - n;

        return QColor::fromHsv(360*i/n + 360/pow(2,p+1), 255, 230);

    }

}