GoldenCheetah/qwt/examples/spectrogram/plot.cpp

#include <qprinter.h>
#include <qprintdialog.h>
#include <qwt_color_map.h>
#include <qwt_plot_spectrogram.h>
#include <qwt_scale_widget.h>
#include <qwt_scale_draw.h>
#include <qwt_plot_zoomer.h>
#include <qwt_plot_panner.h>
#include <qwt_plot_layout.h>
#include <qwt_plot_renderer.h>
#include "plot.h"

class MyZoomer: public QwtPlotZoomer
{
public:
    MyZoomer(QwtPlotCanvas *canvas):
        QwtPlotZoomer(canvas)
    {
        setTrackerMode(AlwaysOn);
    }

    virtual QwtText trackerTextF(const QPointF &pos) const
    {
        QColor bg(Qt::white);
        bg.setAlpha(200);

        QwtText text = QwtPlotZoomer::trackerTextF(pos);
        text.setBackgroundBrush( QBrush( bg ));
        return text;
    }
};

class SpectrogramData: public QwtRasterData
{
public:
    SpectrogramData()
    {
        setInterval( Qt::XAxis, QwtInterval( -1.5, 1.5 ) );
        setInterval( Qt::YAxis, QwtInterval( -1.5, 1.5 ) );
        setInterval( Qt::ZAxis, QwtInterval( 0.0, 10.0 ) );
    }

    virtual double value(double x, double y) const
    {
        const double c = 0.842;

        const double v1 = x * x + (y-c) * (y+c);
        const double v2 = x * (y+c) + x * (y+c);

        return 1.0 / (v1 * v1 + v2 * v2);
    }
};

class ColorMap: public QwtLinearColorMap
{
public:
    ColorMap():
        QwtLinearColorMap(Qt::darkCyan, Qt::red)
    {
        addColorStop(0.1, Qt::cyan);
        addColorStop(0.6, Qt::green);
        addColorStop(0.95, Qt::yellow);
    }
};

Plot::Plot(QWidget *parent):
    QwtPlot(parent)
{
    d_spectrogram = new QwtPlotSpectrogram();
    d_spectrogram->setRenderThreadCount(0); // use system specific thread count

    d_spectrogram->setColorMap(new ColorMap());

    d_spectrogram->setData(new SpectrogramData());
    d_spectrogram->attach(this);

    QList<double> contourLevels;
    for ( double level = 0.5; level < 10.0; level += 1.0 )
        contourLevels += level;
    d_spectrogram->setContourLevels(contourLevels);

    const QwtInterval zInterval = d_spectrogram->data()->interval( Qt::ZAxis );
    // A color bar on the right axis
    QwtScaleWidget *rightAxis = axisWidget(QwtPlot::yRight);
    rightAxis->setTitle("Intensity");
    rightAxis->setColorBarEnabled(true);
    rightAxis->setColorMap( zInterval, new ColorMap());

    setAxisScale(QwtPlot::yRight, zInterval.minValue(), zInterval.maxValue() );
    enableAxis(QwtPlot::yRight);

    plotLayout()->setAlignCanvasToScales(true);
    replot();

    // LeftButton for the zooming
    // MidButton for the panning
    // RightButton: zoom out by 1
    // Ctrl+RighButton: zoom out to full size

    QwtPlotZoomer* zoomer = new MyZoomer(canvas());
    zoomer->setMousePattern(QwtEventPattern::MouseSelect2,
        Qt::RightButton, Qt::ControlModifier);
    zoomer->setMousePattern(QwtEventPattern::MouseSelect3,
        Qt::RightButton);

    QwtPlotPanner *panner = new QwtPlotPanner(canvas());
    panner->setAxisEnabled(QwtPlot::yRight, false);
    panner->setMouseButton(Qt::MidButton);

    // Avoid jumping when labels with more/less digits
    // appear/disappear when scrolling vertically

    const QFontMetrics fm(axisWidget(QwtPlot::yLeft)->font());
    QwtScaleDraw *sd = axisScaleDraw(QwtPlot::yLeft);
    sd->setMinimumExtent( fm.width("100.00") );

    const QColor c(Qt::darkBlue);
    zoomer->setRubberBandPen(c);
    zoomer->setTrackerPen(c);
}

void Plot::showContour(bool on)
{
    d_spectrogram->setDisplayMode(QwtPlotSpectrogram::ContourMode, on);
    replot();
}

void Plot::showSpectrogram(bool on)
{
    d_spectrogram->setDisplayMode(QwtPlotSpectrogram::ImageMode, on);
    d_spectrogram->setDefaultContourPen(on ? QPen() : QPen(Qt::NoPen));
    replot();
}

#ifndef QT_NO_PRINTER

void Plot::printPlot()
{
#if 1
    QPrinter printer;
#else
    QPrinter printer(QPrinter::HighResolution);
#endif
    printer.setOrientation(QPrinter::Landscape);
    printer.setOutputFileName("spectrogram.pdf");
    QPrintDialog dialog(&printer);
    if ( dialog.exec() )
    {
        QwtPlotRenderer renderer;

        renderer.setDiscardFlag(QwtPlotRenderer::DiscardBackground, false);
        renderer.setLayoutFlag(QwtPlotRenderer::KeepFrames, true);

        renderer.renderTo(this, printer);
    }
}

#endif