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");

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

    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);

    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::onPortError(QSerialPort::SerialPortError error)

{

    switch(error)

    {

        case QSerialPort::NoError :

            break;

        case QSerialPort::ResourceError :

            qWarning() << "Port error: resource unavaliable; most likely device removed.";

            if (serialPort.isOpen())

            {

                qWarning() << "Closing port on resource error: " << serialPort.portName();

                portControl.togglePort();

            }

            portControl.loadPortList();

            break;

        case QSerialPort::DeviceNotFoundError:

            qCritical() << "Device doesn't exists: " << serialPort.portName();

            break;

        case QSerialPort::PermissionError:

            qCritical() << "Permission denied. Either you don't have \

required privileges or device is already opened by another process.";

            break;

        case QSerialPort::OpenError:

            qWarning() << "Device is already opened!";

            break;

        case QSerialPort::NotOpenError:

            qCritical() << "Device is not open!";

            break;

        case QSerialPort::ParityError:

            qCritical() << "Parity error detected.";

            break;

        case QSerialPort::FramingError:

            qCritical() << "Framing error detected.";

            break;

        case QSerialPort::BreakConditionError:

            qCritical() << "Break condition is detected.";

            break;

        case QSerialPort::WriteError:

            qCritical() << "An error occurred while writing data.";

            break;

        case QSerialPort::ReadError:

            qCritical() << "An error occurred while reading data.";

            break;

        case QSerialPort::UnsupportedOperationError:

            qCritical() << "Operation is not supported.";

            break;

        case QSerialPort::TimeoutError:

            qCritical() << "A timeout error occurred.";

            break;

        case QSerialPort::UnknownError:

            qCritical() << "Unknown error! Error: " << serialPort.errorString();

            break;

        default:

            qCritical() << "Unhandled port error: " << error;

            break;

    }

}

void MainWindow::clearPlot()

{

    for (unsigned ci = 0; ci < channelMan.numOfChannels(); ci++)

    {

        channelMan.channelBuffer(ci)->clear();

    }

    ui->plot->replot();

}

void MainWindow::onNumOfSamplesChanged(int value)

{

    numOfSamples = value;

    channelMan.setNumOfSamples(value);

    ui->plot->replot();

}

void MainWindow::onNumOfChannelsChanged(unsigned value)

{

    unsigned int oldNum = curves.size();

    unsigned numOfChannels = value;

    if (numOfChannels > oldNum)

    {

        // add new channels

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

        {

            QwtPlotCurve* curve = new QwtPlotCurve(channelMan.channelName(i));

            // TODO: create a wrapper around FrameBuffer that holds a

            // pointer to it and provides the QwtDataSeries interface,

            // that wrapper should be created for and owned by 'curve'

            curve->setSamples(channelMan.channelBuffer(i));

            curve->setPen(Plot::makeColor(i));

            curve->attach(ui->plot);

            curves.append(curve);

        }

    }

    else if(numOfChannels < oldNum)

    {

        // remove channels

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

        {

            // also deletes owned FrameBuffer TODO: which souldn't happen

            delete curves.takeLast();

        }

    }

    ui->plot->replot();

}

void MainWindow::onChannelNameChanged(unsigned channel, QString name)

{

    // This slot is triggered also when a new channel is added, in

    // this case curve list doesn't contain said channel. No worries,

    // since `onNumOfChannelsChanged` slot will update curve list.

    {

        curves[channel]->setTitle(name);

        ui->plot->replot();

    }

}

void MainWindow::onAutoScaleChecked(bool checked)

{

    if (checked)

    {

        ui->plot->setAxis(true);

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

    }

}

void MainWindow::onYScaleChanged()

{

    ui->plot->setAxis(false,  ui->spYmin->value(), ui->spYmax->value());

}

void MainWindow::onRangeSelected()

{

    Range r = ui->cbRangePresets->currentData().value<Range>();

    ui->spYmin->setValue(r.rmin);

    ui->spYmax->setValue(r.rmax);

    ui->cbAutoScale->setChecked(false);

}

void MainWindow::onSpsChanged(unsigned sps)

{

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

}

bool MainWindow::isDemoRunning()

{

    return ui->actionDemoMode->isChecked();

}

void MainWindow::enableDemo(bool enabled)

{

    if (enabled)

    {

        if (!serialPort.isOpen())

        {

            dataFormatPanel.enableDemo(true);

            ui->actionDemoMode->setChecked(true);

            demoIndicator.show();

            ui->plot->replot();

        }

        else

        {

            ui->actionDemoMode->setChecked(false);

        }

    }

    else

    {

        dataFormatPanel.enableDemo(false);

        ui->actionDemoMode->setChecked(false);

        demoIndicator.hide();

        ui->plot->replot();

    }

}

void MainWindow::onExportCsv()

{

    bool wasPaused = ui->actionPause->isChecked();

    ui->actionPause->setChecked(true); // pause plotting

    QString fileName = QFileDialog::getSaveFileName(this, tr("Export CSV File"));

    if (fileName.isNull())  // user canceled export

    {

        ui->actionPause->setChecked(wasPaused);

    }

    else

    {

        QFile file(fileName);

        if (file.open(QIODevice::WriteOnly | QIODevice::Text))

        {

            QTextStream fileStream(&file);

            unsigned numOfChannels = channelMan.numOfChannels();

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

            {

                fileStream << "Channel " << ci;

                if (ci != numOfChannels-1) fileStream << ",";

            }

            fileStream << '\n';

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

            {

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

                {

                    fileStream << channelMan.channelBuffer(ci)->sample(i).y();

                    if (ci != numOfChannels-1) fileStream << ",";

                }

                fileStream << '\n';

            }

        }

        else

        {

            qCritical() << "File open error during export: " << file.error();

        }

    }

}

void MainWindow::messageHandler(QtMsgType type,

                                const QMessageLogContext &context,

                                const QString &msg)

{

    QString logString;

    switch (type)

    {

        case QtDebugMsg:

            logString = "[Debug] " + msg;

            break;

        case QtWarningMsg:

            logString = "[Warning] " + msg;

            break;

        case QtCriticalMsg:

            logString = "[Error] " + msg;

            break;

        case QtFatalMsg:

            logString = "[Fatal] " + msg;

            break;

    }

    if (ui != NULL) ui->ptLog->appendPlainText(logString);

    std::cerr << logString.toStdString() << std::endl;

    if (type != QtDebugMsg && ui != NULL)

    {

        ui->statusBar->showMessage(msg, 5000);

    }

}