this, &MainWindow::close);

    // port control signals

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

                     this, &MainWindow::onPortToggled);

    connect(&plotControlPanel, &PlotControlPanel::numOfSamplesChanged,

            this, &MainWindow::onNumOfSamplesChanged);

    connect(&plotControlPanel, &PlotControlPanel::scaleChanged,

            plotMan, &PlotManager::setAxis);

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

                     this, SLOT(clearPlot()));

    QObject::connect(snapshotMan.takeSnapshotAction(), &QAction::triggered,

                     plotMan, &PlotManager::flashSnapshotOverlay);

    // init port signals

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

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

    // init data format and reader

    QObject::connect(&dataFormatPanel, &DataFormatPanel::dataAdded,

    connect(ui->spNumOfSamples, SIGNAL(valueChanged(int)),

            this, SIGNAL(numOfSamplesChanged(int)));

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

            this, &PlotControlPanel::onAutoScaleChecked);

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

            this, SLOT(onYScaleChanged()));

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

            this, SLOT(onYScaleChanged()));

    // 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

    {

void PlotControlPanel::onRangeSelected()

{

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

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

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

    ui->cbAutoScale->setChecked(false);

}

void PlotControlPanel::setChannelNamesModel(QAbstractItemModel * model)

{

    ui->lvChannelNames->setModel(model);

}

class PlotControlPanel : public QWidget

{

    Q_OBJECT

public:

    explicit PlotControlPanel(QWidget *parent = 0);

    ~PlotControlPanel();

    unsigned numOfSamples();

    bool autoScale();

    double yMax();

    double yMin();

    void setChannelNamesModel(QAbstractItemModel * model);

signals:

    void numOfSamplesChanged(int value);

    void scaleChanged(bool autoScaled, double yMin = 0, double yMax = 1);

private:

    Ui::PlotControlPanel *ui;

private slots:

    void onAutoScaleChecked(bool checked);

    void onYScaleChanged();

    void onRangeSelected();

};

#endif // PLOTCONTROLPANEL_H

<?xml version="1.0" encoding="UTF-8"?>

<ui version="4.0">

 <class>PlotControlPanel</class>

 <widget class="QWidget" name="PlotControlPanel">

  <property name="geometry">

   <rect>

    <x>0</x>

    <y>0</y>

    <width>590</width>

   </rect>

  </property>

  <property name="windowTitle">

   <string>Form</string>

  </property>

  <layout class="QHBoxLayout" name="horizontalLayout">

   <item>

    <layout class="QVBoxLayout" name="verticalLayout">

     <item>

      <widget class="QLabel" name="label_2">

       <property name="styleSheet">

        <string notr="true">font-weight: bold;</string>

         <width>75</width>

         <height>16777215</height>

        </size>

       </property>

       <property name="toolTip">

        <string>lower limit of Y axis</string>

       </property>

       <property name="value">

        <double>0.000000000000000</double>

       </property>

      </widget>

     </item>

     <item row="4" column="0">

      <widget class="QLabel" name="label">

       <property name="text">

        <string>Select Range Preset:</string>

       </property>

      </widget>

     </item>

     </item>

    </layout>

   </item>

  </layout>

 </widget>

 <resources/>

 <connections/>

</ui>

#include "plot.h"

#include "plotmanager.h"

#include "utils.h"

PlotManager::PlotManager(QWidget* plotArea, QObject *parent) :

    QObject(parent),

    _plotArea(plotArea),

    showGridAction("Grid", this),

    showMinorGridAction("Minor Grid", this),

    unzoomAction("Unzoom", this),

    darkBackgroundAction("Dark Background", this),

{

    _autoScaled = true;

    _yMin = 0;

    _yMax = 1;

    isDemoShown = false;

    // initalize layout and single widget

    isMulti = false;

    scrollArea = NULL;

    setupLayout(isMulti);

    addPlotWidget();

    // initialize menu actions

    showGridAction.setToolTip("Show Grid");

    showMinorGridAction.setToolTip("Show Minor Grid");

    unzoomAction.setToolTip("Unzoom the Plot");

    darkBackgroundAction.setToolTip("Enable Dark Plot Background");

    showLegendAction.setToolTip("Display the Legend on Plot");

    showGridAction.setShortcut(QKeySequence("G"));

    showMinorGridAction.setShortcut(QKeySequence("M"));

    showGridAction.setCheckable(true);

    showMinorGridAction.setCheckable(true);

    darkBackgroundAction.setCheckable(true);

    showLegendAction.setCheckable(true);

    showGridAction.setChecked(false);

    showMinorGridAction.setChecked(false);

    darkBackgroundAction.setChecked(false);

    showLegendAction.setChecked(true);

    showMinorGridAction.setEnabled(false);

    connect(&showGridAction, SELECT<bool>::OVERLOAD_OF(&QAction::triggered),

            this, &PlotManager::showGrid);

    connect(&showGridAction, SELECT<bool>::OVERLOAD_OF(&QAction::triggered),

            &showMinorGridAction, &QAction::setEnabled);

    connect(&showMinorGridAction, SELECT<bool>::OVERLOAD_OF(&QAction::triggered),

            this, &PlotManager::showMinorGrid);

    connect(&unzoomAction, &QAction::triggered, this, &PlotManager::unzoom);

    connect(&darkBackgroundAction, SELECT<bool>::OVERLOAD_OF(&QAction::triggered),

            this, &PlotManager::darkBackground);

    connect(&showLegendAction, SELECT<bool>::OVERLOAD_OF(&QAction::triggered),

            this, &PlotManager::showLegend);

}

PlotManager::~PlotManager()

{

    while (curves.size())

    {

        delete curves.takeLast();

    }

    // remove all widgets

    while (plotWidgets.size())

    {

        plot->replot();

    }

}

QList<QAction*> PlotManager::menuActions()

{

    QList<QAction*> actions;

    actions << &showGridAction;

    actions << &showMinorGridAction;

    actions << &unzoomAction;

    actions << &darkBackgroundAction;

    actions << &showLegendAction;

    return actions;

}

void PlotManager::showGrid(bool show)

{

    for (auto plot : plotWidgets)

    {

        plot->showGrid(show);

    }

}

void PlotManager::showMinorGrid(bool show)

    QList<Plot*> plotWidgets;

    bool isDemoShown;

    bool _autoScaled;

    double _yMin;

    double _yMax;

    // menu actions

    QAction showGridAction;

    QAction showMinorGridAction;

    QAction unzoomAction;

    QAction darkBackgroundAction;

    QAction showLegendAction;

    void setupLayout(bool multiPlot);

    /// Inserts a new plot widget to the current layout.

    Plot* addPlotWidget();

    /// Returns the plot widget that given curve is attached to

    Plot* plotWidget(unsigned curveIndex);

    /// Common part of overloaded `addCurve` functions

    void _addCurve(QwtPlotCurve* curve);

private slots:

    void showGrid(bool show = true);

    void showMinorGrid(bool show = true);