qt_demoe/qwtdemo/examples/friedberg/plot.cpp

#include "plot.h"
#include "friedberg2007.h"
#include <qwt_plot_zoomer.h>
#include <qwt_plot_panner.h>
#include <qwt_plot_marker.h>
#include <qwt_plot_grid.h>
#include <qwt_plot_curve.h>
#include <qwt_plot_canvas.h>
#include <qwt_plot_intervalcurve.h>
#include <qwt_legend.h>
#include <qwt_interval_symbol.h>
#include <qwt_symbol.h>
#include <qwt_series_data.h>
#include <qwt_text.h>
#include <qwt_scale_draw.h>
#include <qwt_plot_renderer.h>
#include <qdatetime.h>

class Grid: public QwtPlotGrid
{
public:
    Grid()
    {
        enableXMin( true );
        setMajorPen( Qt::white, 0, Qt::DotLine );
        setMinorPen( Qt::gray, 0, Qt::DotLine );
    }

    virtual void updateScaleDiv( const QwtScaleDiv &xScaleDiv,
        const QwtScaleDiv &yScaleDiv )
    {
        QwtScaleDiv scaleDiv( xScaleDiv.lowerBound(), 
            xScaleDiv.upperBound() );

        scaleDiv.setTicks( QwtScaleDiv::MinorTick,
            xScaleDiv.ticks( QwtScaleDiv::MinorTick ) );
        scaleDiv.setTicks( QwtScaleDiv::MajorTick,
            xScaleDiv.ticks( QwtScaleDiv::MediumTick ) );

        QwtPlotGrid::updateScaleDiv( scaleDiv, yScaleDiv );
    }
};

class YearScaleDraw: public QwtScaleDraw
{
public:
    YearScaleDraw()
    {
        setTickLength( QwtScaleDiv::MajorTick, 0 );
        setTickLength( QwtScaleDiv::MinorTick, 0 );
        setTickLength( QwtScaleDiv::MediumTick, 6 );

        setLabelRotation( -60.0 );
        setLabelAlignment( Qt::AlignLeft | Qt::AlignVCenter );

        setSpacing( 15 );
    }

    virtual QwtText label( double value ) const
    {
        return QDate::longMonthName( int( value / 30 ) + 1 );
    }
};

Plot::Plot( QWidget *parent ):
    QwtPlot( parent )
{
    setObjectName( "FriedbergPlot" );
    setTitle( "Temperature of Friedberg/Germany" );

    setAxisTitle( QwtPlot::xBottom, "2007" );
    setAxisScaleDiv( QwtPlot::xBottom, yearScaleDiv() );
    setAxisScaleDraw( QwtPlot::xBottom, new YearScaleDraw() );

    setAxisTitle( QwtPlot::yLeft,
        QString( "Temperature [%1C]" ).arg( QChar( 0x00B0 ) ) );

    QwtPlotCanvas *canvas = new QwtPlotCanvas();
    canvas->setPalette( Qt::darkGray );
    canvas->setBorderRadius( 10 );

    setCanvas( canvas );

    // grid
    QwtPlotGrid *grid = new Grid;
    grid->attach( this );

    insertLegend( new QwtLegend(), QwtPlot::RightLegend );

    const int numDays = 365;
    QVector<QPointF> averageData( numDays );
    QVector<QwtIntervalSample> rangeData( numDays );

    for ( int i = 0; i < numDays; i++ )
    {
        const Temperature &t = friedberg2007[i];
        averageData[i] = QPointF( double( i ), t.averageValue );
        rangeData[i] = QwtIntervalSample( double( i ),
            QwtInterval( t.minValue, t.maxValue ) );
    }

    insertCurve( "Average", averageData, Qt::black );
    insertErrorBars( "Range", rangeData, Qt::blue );

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

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

    QwtPlotPanner *panner = new QwtPlotPanner( canvas );
    panner->setMouseButton( Qt::MidButton );
}

QwtScaleDiv Plot::yearScaleDiv() const
{
    const int days[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

    QList<double> mediumTicks;
    mediumTicks += 0.0;
    for ( uint i = 0; i < sizeof( days ) / sizeof( days[0] ); i++ )
        mediumTicks += mediumTicks.last() + days[i];

    QList<double> minorTicks;
    for ( int i = 1; i <= 365; i += 7 )
        minorTicks += i;

    QList<double> majorTicks;
    for ( int i = 0; i < 12; i++ )
        majorTicks += i * 30 + 15;

    QwtScaleDiv scaleDiv( mediumTicks.first(), mediumTicks.last() + 1, 
        minorTicks, mediumTicks, majorTicks );
    return scaleDiv;
}

void Plot::insertCurve( const QString& title,
    const QVector<QPointF>& samples, const QColor &color )
{
    d_curve = new QwtPlotCurve( title );
    d_curve->setRenderHint( QwtPlotItem::RenderAntialiased );
    d_curve->setStyle( QwtPlotCurve::NoCurve );
    d_curve->setLegendAttribute( QwtPlotCurve::LegendShowSymbol );

    QwtSymbol *symbol = new QwtSymbol( QwtSymbol::XCross );
    symbol->setSize( 4 );
    symbol->setPen( color );
    d_curve->setSymbol( symbol );

    d_curve->setSamples( samples );
    d_curve->attach( this );
}

void Plot::insertErrorBars(
    const QString &title,
    const QVector<QwtIntervalSample>& samples,
    const QColor &color )
{
    d_intervalCurve = new QwtPlotIntervalCurve( title );
    d_intervalCurve->setRenderHint( QwtPlotItem::RenderAntialiased );
    d_intervalCurve->setPen( Qt::white );

    QColor bg( color );
    bg.setAlpha( 150 );
    d_intervalCurve->setBrush( QBrush( bg ) );
    d_intervalCurve->setStyle( QwtPlotIntervalCurve::Tube );

    d_intervalCurve->setSamples( samples );
    d_intervalCurve->attach( this );
}

void Plot::setMode( int style )
{
    if ( style == Tube )
    {
        d_intervalCurve->setStyle( QwtPlotIntervalCurve::Tube );
        d_intervalCurve->setSymbol( NULL );
        d_intervalCurve->setRenderHint( QwtPlotItem::RenderAntialiased, true );
    }
    else
    {
        d_intervalCurve->setStyle( QwtPlotIntervalCurve::NoCurve );

        QColor c( d_intervalCurve->brush().color().rgb() ); // skip alpha

        QwtIntervalSymbol *errorBar =
            new QwtIntervalSymbol( QwtIntervalSymbol::Bar );
        errorBar->setWidth( 8 ); // should be something even
        errorBar->setPen( c );

        d_intervalCurve->setSymbol( errorBar );
        d_intervalCurve->setRenderHint( QwtPlotItem::RenderAntialiased, false );
    }

    replot();
}

void Plot::exportPlot()
{
    QwtPlotRenderer renderer;
    renderer.exportTo( this, "friedberg.pdf" );
}