// save settings

    QSettings settings("serialplot", "serialplot");

    saveAllSettings(&settings);

    settings.sync();

    if (settings.status() != QSettings::NoError)

    {

        QString errorText;

        if (settings.status() == QSettings::AccessError)

        {

            QString file = settings.fileName();

            errorText = QString("Serialplot cannot save settings due to access error. \

This happens if you have run serialplot as root (with sudo for ex.) previously. \

Try fixing the permissions of file: %1, or just delete it.").arg(file);

        }

        else

        {

            errorText = QString("Serialplot cannot save settings due to unknown error: %1").\

                arg(settings.status());

        }

        auto button = QMessageBox::critical(

            NULL,

            "Failed to save settings!", errorText,

            QMessageBox::Cancel | QMessageBox::Ok);

        if (button == QMessageBox::Cancel)

        {

            event->ignore();

            return;

        }

    }

    QMainWindow::closeEvent(event);

}

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();

    }

    plotMan->replot();

}

void MainWindow::onNumOfSamplesChanged(int value)

{

    numOfSamples = value;

    channelMan.setNumOfSamples(value);

    plotMan->replot();

}

void MainWindow::onNumOfChannelsChanged(unsigned value)

{

    unsigned int oldNum = plotMan->numOfCurves();

    unsigned numOfChannels = value;

    if (numOfChannels > oldNum)

    {

        // add new channels

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

        {

            plotMan->addCurve(channelMan.channelName(i), channelMan.channelBuffer(i));

        }

    }

    else if(numOfChannels < oldNum)

    {

        plotMan->removeCurves(oldNum - numOfChannels);

    }

    plotMan->replot();

}

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);

        }

        else

        {

            ui->actionDemoMode->setChecked(false);

        }

    }

    else

    {

        dataFormatPanel.enableDemo(false);

        ui->actionDemoMode->setChecked(false);

    }

}

void MainWindow::showSecondary(QWidget* wid)

{

    if (secondaryPlot != NULL)

    {

        secondaryPlot->deleteLater();

    }

    secondaryPlot = wid;

    ui->splitter->addWidget(wid);

}

void MainWindow::hideSecondary()

{

    if (secondaryPlot == NULL)

    {

        qFatal("Secondary plot doesn't exist!");

    }

    secondaryPlot->deleteLater();

    secondaryPlot = NULL;

}

void MainWindow::showBarPlot(bool show)

{

    if (show)

    {

        auto plot = new BarPlot(&channelMan);

        plot->setYAxis(plotControlPanel.autoScale(),

                       plotControlPanel.yMin(),

                       plotControlPanel.yMax());

        connect(&plotControlPanel, &PlotControlPanel::yScaleChanged,

                plot, &BarPlot::setYAxis);

        showSecondary(plot);

    }

    else

    {

        hideSecondary();

    }

}

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

    {

        Snapshot* snapshot = snapshotMan.makeSnapshot();

        snapshot->save(fileName);

        delete snapshot;

    }

}

PlotViewSettings MainWindow::viewSettings() const

{

    return plotMan->viewSettings();

}

void MainWindow::messageHandler(QtMsgType type,

                                const QMessageLogContext &context,

                                const QString &msg)

{

    QString logString;

    switch (type)

    {

#if (QT_VERSION >= QT_VERSION_CHECK(5, 5, 0))

        case QtInfoMsg:

            logString = "[Info] " + msg;

            break;

#endif

        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);

    }

    if (type == QtFatalMsg)

    {

        __builtin_trap();

    }

}

void MainWindow::saveAllSettings(QSettings* settings)

{

    saveMWSettings(settings);

    portControl.saveSettings(settings);

    dataFormatPanel.saveSettings(settings);

    channelMan.saveSettings(settings);

    plotControlPanel.saveSettings(settings);

    plotMan->saveSettings(settings);

    commandPanel.saveSettings(settings);

    recordPanel.saveSettings(settings);

    updateCheckDialog.saveSettings(settings);

}

void MainWindow::loadAllSettings(QSettings* settings)

{

    loadMWSettings(settings);

    portControl.loadSettings(settings);

    dataFormatPanel.loadSettings(settings);

    channelMan.loadSettings(settings);

    plotControlPanel.loadSettings(settings);

    plotMan->loadSettings(settings);

    commandPanel.loadSettings(settings);

    recordPanel.loadSettings(settings);

    updateCheckDialog.loadSettings(settings);

}

void MainWindow::saveMWSettings(QSettings* settings)

{

    // save window geometry

    settings->beginGroup(SettingGroup_MainWindow);

    settings->setValue(SG_MainWindow_Size, size());

    settings->setValue(SG_MainWindow_Pos, pos());

    // save active panel

    settings->setValue(SG_MainWindow_ActivePanel,

                       panelSettingMap.value(ui->tabWidget->currentIndex()));

    // save panel minimization

    settings->setValue(SG_MainWindow_HidePanels,

                       ui->tabWidget->hideAction.isChecked());

    // save window maximized state

    settings->setValue(SG_MainWindow_Maximized,

                       bool(windowState() & Qt::WindowMaximized));

    // save toolbar/dockwidgets state

    settings->setValue(SG_MainWindow_State, saveState());

    settings->endGroup();

}

void MainWindow::loadMWSettings(QSettings* settings)

{

    settings->beginGroup(SettingGroup_MainWindow);

    // load window geometry

    resize(settings->value(SG_MainWindow_Size, size()).toSize());

    move(settings->value(SG_MainWindow_Pos, pos()).toPoint());

    // set active panel

    QString tabSetting =

        settings->value(SG_MainWindow_ActivePanel, QString()).toString();

    ui->tabWidget->setCurrentIndex(

        panelSettingMap.key(tabSetting, ui->tabWidget->currentIndex()));

    // hide panels

    ui->tabWidget->hideAction.setChecked(

        settings->value(SG_MainWindow_HidePanels,

                        ui->tabWidget->hideAction.isChecked()).toBool());

    // maximize window

    if (settings->value(SG_MainWindow_Maximized).toBool())

    {

        showMaximized();

    }

    // load toolbar/dockwidgets state

    restoreState(settings->value(SG_MainWindow_State).toByteArray());

    settings->setValue(SG_MainWindow_State, saveState());

    settings->endGroup();

}

void MainWindow::onSaveSettings()

{

    QString fileName = QFileDialog::getSaveFileName(

        this, tr("Save Settings"), QString(), "INI (*.ini)");

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

    {

        QSettings settings(fileName, QSettings::IniFormat);

        saveAllSettings(&settings);

    }

}

void MainWindow::onLoadSettings()

{

    QString fileName = QFileDialog::getOpenFileName(

        this, tr("Load Settings"), QString(), "INI (*.ini)");

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

    {