qwt_plot_multi_barchart.cpp

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/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
 * Qwt Widget Library
 * Copyright (C) 1997   Josef Wilgen
 * Copyright (C) 2002   Uwe Rathmann
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the Qwt License, Version 1.0
 *****************************************************************************/

#include "qwt_plot_multi_barchart.h"
#include "qwt_scale_map.h"
#include "qwt_column_symbol.h"
#include "qwt_text.h"
#include "qwt_graphic.h"
#include "qwt_legend_data.h"
#include "qwt_math.h"

#include <qmap.h>

inline static bool qwtIsIncreasing(
    const QwtScaleMap &map, const QVector<double> &values )
{
    bool isInverting = map.isInverting();

    for ( int i = 0; i < values.size(); i++ )
    {
        const double y = values[ i ];
        if ( y != 0.0 )
            return ( map.isInverting() != ( y > 0.0 ) );
    }

    return !isInverting;
}

class QwtPlotMultiBarChart::PrivateData
{
public:
    PrivateData():
        style( QwtPlotMultiBarChart::Grouped )
    {
    }

    QwtPlotMultiBarChart::ChartStyle style;
    QList<QwtText> barTitles;
    QMap<int, QwtColumnSymbol *> symbolMap;
};

QwtPlotMultiBarChart::QwtPlotMultiBarChart( const QwtText &title ):
    QwtPlotAbstractBarChart( title )
{
    init();
}

QwtPlotMultiBarChart::QwtPlotMultiBarChart( const QString &title ):
    QwtPlotAbstractBarChart( QwtText( title ) )
{
    init();
}

QwtPlotMultiBarChart::~QwtPlotMultiBarChart()
{
    resetSymbolMap();
    delete d_data;
}

void QwtPlotMultiBarChart::init()
{
    d_data = new PrivateData;
    setData( new QwtSetSeriesData() );
}

int QwtPlotMultiBarChart::rtti() const
{
    return QwtPlotItem::Rtti_PlotMultiBarChart;
}

void QwtPlotMultiBarChart::setSamples(
    const QVector<QwtSetSample> &samples )
{
    setData( new QwtSetSeriesData( samples ) );
}

void QwtPlotMultiBarChart::setSamples(
    const QVector< QVector<double> > &samples )
{
    QVector<QwtSetSample> s;
    s.reserve( samples.size() );

    for ( int i = 0; i < samples.size(); i++ )
        s += QwtSetSample( i, samples[ i ] );

    setData( new QwtSetSeriesData( s ) );
}

void QwtPlotMultiBarChart::setSamples(
    QwtSeriesData<QwtSetSample> *data )
{
    setData( data );
}

void QwtPlotMultiBarChart::setBarTitles( const QList<QwtText> &titles )
{
    d_data->barTitles = titles;
    itemChanged();
}

QList<QwtText> QwtPlotMultiBarChart::barTitles() const
{
    return d_data->barTitles;
}

void QwtPlotMultiBarChart::setSymbol( int valueIndex, QwtColumnSymbol *symbol )
{
    if ( valueIndex < 0 )
        return;

    QMap<int, QwtColumnSymbol *>::iterator it =
        d_data->symbolMap.find(valueIndex);
    if ( it == d_data->symbolMap.end() )
    {
        if ( symbol != NULL )
        {
            d_data->symbolMap.insert( valueIndex, symbol );

            legendChanged();
            itemChanged();
        }
    }
    else
    {
        if ( symbol != it.value() )
        {
            delete it.value();

            if ( symbol == NULL )
            {
                d_data->symbolMap.remove( valueIndex );
            }
            else
            {
                it.value() = symbol;
            }

            legendChanged();
            itemChanged();
        }
    }
}

const QwtColumnSymbol *QwtPlotMultiBarChart::symbol( int valueIndex ) const
{
    QMap<int, QwtColumnSymbol *>::const_iterator it =
        d_data->symbolMap.constFind( valueIndex );

    return ( it == d_data->symbolMap.constEnd() ) ? NULL : it.value();
}

QwtColumnSymbol *QwtPlotMultiBarChart::symbol( int valueIndex )
{
    QMap<int, QwtColumnSymbol *>::const_iterator it =
        d_data->symbolMap.constFind( valueIndex );

    return ( it == d_data->symbolMap.constEnd() ) ? NULL : it.value();
}

void QwtPlotMultiBarChart::resetSymbolMap()
{
    qDeleteAll( d_data->symbolMap );
    d_data->symbolMap.clear();
}

QwtColumnSymbol *QwtPlotMultiBarChart::specialSymbol(
    int sampleIndex, int valueIndex ) const
{
    Q_UNUSED( sampleIndex );
    Q_UNUSED( valueIndex );

    return NULL;
}

void QwtPlotMultiBarChart::setStyle( ChartStyle style )
{
    if ( style != d_data->style )
    {
        d_data->style = style;

        legendChanged();
        itemChanged();
    }
}

QwtPlotMultiBarChart::ChartStyle QwtPlotMultiBarChart::style() const
{
    return d_data->style;
}

QRectF QwtPlotMultiBarChart::boundingRect() const
{
    const size_t numSamples = dataSize();

    if ( numSamples == 0 )
        return QwtPlotSeriesItem::boundingRect();

    const double baseLine = baseline();

    QRectF rect;

    if ( d_data->style != QwtPlotMultiBarChart::Stacked )
    {
        rect = QwtPlotSeriesItem::boundingRect();

        if ( rect.height() >= 0 )
        {
            if ( rect.bottom() < baseLine )
                rect.setBottom( baseLine );
            if ( rect.top() > baseLine )
                rect.setTop( baseLine );
        }
    }
    else
    {
        double xMin, xMax, yMin, yMax;

        xMin = xMax = 0.0;
        yMin = yMax = baseLine;

        const QwtSeriesData<QwtSetSample> *series = data();

        for ( size_t i = 0; i < numSamples; i++ )
        {
            const QwtSetSample sample = series->sample( i );
            if ( i == 0 )
            {
                xMin = xMax = sample.value;
            }
            else
            {
                xMin = qwtMinF( xMin, sample.value );
                xMax = qwtMaxF( xMax, sample.value );
            }

            const double y = baseLine + sample.added();

            yMin = qwtMinF( yMin, y );
            yMax = qwtMaxF( yMax, y );
        }
        rect.setRect( xMin, yMin, xMax - xMin, yMax - yMin );
    }

    if ( orientation() == Qt::Horizontal )
        rect.setRect( rect.y(), rect.x(), rect.height(), rect.width() );

    return rect;
}

void QwtPlotMultiBarChart::drawSeries( QPainter *painter,
    const QwtScaleMap &xMap, const QwtScaleMap &yMap,
    const QRectF &canvasRect, int from, int to ) const
{
    if ( to < 0 )
        to = dataSize() - 1;

    if ( from < 0 )
        from = 0;

    if ( from > to )
        return;


    const QRectF br = data()->boundingRect();
    const QwtInterval interval( br.left(), br.right() );

    painter->save();

    for ( int i = from; i <= to; i++ )
    {
        drawSample( painter, xMap, yMap,
            canvasRect, interval, i, sample( i ) );
    }

    painter->restore();
}

void QwtPlotMultiBarChart::drawSample( QPainter *painter,
    const QwtScaleMap &xMap, const QwtScaleMap &yMap,
    const QRectF &canvasRect, const QwtInterval &boundingInterval,
    int index, const QwtSetSample& sample ) const
{
    if ( sample.set.size() <= 0 )
        return;

    double sampleW;

    if ( orientation() == Qt::Horizontal )
    {
        sampleW = sampleWidth( yMap, canvasRect.height(),
            boundingInterval.width(), sample.value );
    }
    else
    {
        sampleW = sampleWidth( xMap, canvasRect.width(),
            boundingInterval.width(), sample.value );
    }

    if ( d_data->style == Stacked )
    {
        drawStackedBars( painter, xMap, yMap,
            canvasRect, index, sampleW, sample );
    }
    else
    {
        drawGroupedBars( painter, xMap, yMap,
            canvasRect, index, sampleW, sample );
    }
}

void QwtPlotMultiBarChart::drawGroupedBars( QPainter *painter,
    const QwtScaleMap &xMap, const QwtScaleMap &yMap,
    const QRectF &canvasRect, int index, double sampleWidth,
    const QwtSetSample& sample ) const
{
    Q_UNUSED( canvasRect );

    const int numBars = sample.set.size();
    if ( numBars == 0 )
        return;

    if ( orientation() == Qt::Vertical )
    {
        const double barWidth = sampleWidth / numBars;

        const double y1 = yMap.transform( baseline() );
        const double x0 = xMap.transform( sample.value ) - 0.5 * sampleWidth;

        for ( int i = 0; i < numBars; i++ )
        {
            const double x1 = x0 + i * barWidth;
            const double x2 = x1 + barWidth;

            const double y2 = yMap.transform( sample.set[i] );

            QwtColumnRect barRect;
            barRect.direction = ( y1 < y2 ) ?
                QwtColumnRect::TopToBottom : QwtColumnRect::BottomToTop;

            barRect.hInterval = QwtInterval( x1, x2 ).normalized();
            if ( i != 0 )
                barRect.hInterval.setBorderFlags( QwtInterval::ExcludeMinimum );

            barRect.vInterval = QwtInterval( y1, y2 ).normalized();

            drawBar( painter, index, i, barRect );
        }
    }
    else
    {
        const double barHeight = sampleWidth / numBars;

        const double x1 = xMap.transform( baseline() );
        const double y0 = yMap.transform( sample.value ) - 0.5 * sampleWidth;

        for ( int i = 0; i < numBars; i++ )
        {
            double y1 = y0 + i * barHeight;
            double y2 = y1 + barHeight;

            double x2 = xMap.transform( sample.set[i] );

            QwtColumnRect barRect;
            barRect.direction = x1 < x2 ?
                QwtColumnRect::LeftToRight : QwtColumnRect::RightToLeft;

            barRect.hInterval = QwtInterval( x1, x2 ).normalized();

            barRect.vInterval = QwtInterval( y1, y2 );
            if ( i != 0 )
                barRect.vInterval.setBorderFlags( QwtInterval::ExcludeMinimum );

            drawBar( painter, index, i, barRect );
        }
    }
}

void QwtPlotMultiBarChart::drawStackedBars( QPainter *painter,
    const QwtScaleMap &xMap, const QwtScaleMap &yMap,
    const QRectF &canvasRect, int index,
    double sampleWidth, const QwtSetSample& sample ) const
{
    Q_UNUSED( canvasRect ); // clipping the bars ?

    const int numBars = sample.set.size();
    if ( numBars == 0 )
        return;

    QwtInterval::BorderFlag borderFlags = QwtInterval::IncludeBorders;

    if ( orientation() == Qt::Vertical )
    {
        const double x1 = xMap.transform( sample.value ) - 0.5 * sampleWidth;
        const double x2 = x1 + sampleWidth;

        const bool increasing = qwtIsIncreasing( yMap, sample.set );

        QwtColumnRect bar;
        bar.direction = increasing ?
            QwtColumnRect::TopToBottom : QwtColumnRect::BottomToTop;

        bar.hInterval = QwtInterval( x1, x2 ).normalized();

        double sum = baseline();

        for ( int i = 0; i < numBars; i++ )
        {
            const double si = sample.set[ i ];
            if ( si == 0.0 )
                continue;

            const double y1 = yMap.transform( sum );
            const double y2 = yMap.transform( sum + si );

            if ( ( y2 > y1 ) != increasing )
            {
                // stacked bars need to be in the same direction
                continue;
            }

            bar.vInterval = QwtInterval( y1, y2 ).normalized();
            bar.vInterval.setBorderFlags( borderFlags );

            drawBar( painter, index, i, bar );

            sum += si;

            if ( increasing )
                borderFlags = QwtInterval::ExcludeMinimum;
            else
                borderFlags = QwtInterval::ExcludeMaximum;
        }
    }
    else
    {
        const double y1 = yMap.transform( sample.value ) - 0.5 * sampleWidth;
        const double y2 = y1 + sampleWidth;

        const bool increasing = qwtIsIncreasing( xMap, sample.set );

        QwtColumnRect bar;
        bar.direction = increasing ?
            QwtColumnRect::LeftToRight : QwtColumnRect::RightToLeft;
        bar.vInterval = QwtInterval( y1, y2 ).normalized();

        double sum = baseline();

        for ( int i = 0; i < sample.set.size(); i++ )
        {
            const double si = sample.set[ i ];
            if ( si == 0.0 )
                continue;

            const double x1 = xMap.transform( sum );
            const double x2 = xMap.transform( sum + si );

            if ( ( x2 > x1 ) != increasing )
            {
                // stacked bars need to be in the same direction
                continue;
            }

            bar.hInterval = QwtInterval( x1, x2 ).normalized();
            bar.hInterval.setBorderFlags( borderFlags );

            drawBar( painter, index, i, bar );

            sum += si;

            if ( increasing )
                borderFlags = QwtInterval::ExcludeMinimum;
            else
                borderFlags = QwtInterval::ExcludeMaximum;
        }
    }
}

void QwtPlotMultiBarChart::drawBar( QPainter *painter,
    int sampleIndex, int valueIndex, const QwtColumnRect &rect ) const
{
    const QwtColumnSymbol *specialSym = NULL;
    if ( sampleIndex >= 0 )
        specialSym = specialSymbol( sampleIndex, valueIndex );

    const QwtColumnSymbol *sym = specialSym;
    if ( sym == NULL )
        sym = symbol( valueIndex );

    if ( sym )
    {
        sym->draw( painter, rect );
    }
    else
    {
        // we build a temporary default symbol
        QwtColumnSymbol columnSymbol( QwtColumnSymbol::Box );
        columnSymbol.setLineWidth( 1 );
        columnSymbol.setFrameStyle( QwtColumnSymbol::Plain );
        columnSymbol.draw( painter, rect );
    }

    delete specialSym;
}

QList<QwtLegendData> QwtPlotMultiBarChart::legendData() const
{
    QList<QwtLegendData> list;
    list.reserve( d_data->barTitles.size() );

    for ( int i = 0; i < d_data->barTitles.size(); i++ )
    {
        QwtLegendData data;

        data.setValue( QwtLegendData::TitleRole,
            QVariant::fromValue( d_data->barTitles[i] ) );

        if ( !legendIconSize().isEmpty() )
        {
            data.setValue( QwtLegendData::IconRole,
                QVariant::fromValue( legendIcon( i, legendIconSize() ) ) );
        }

        list += data;
    }

    return list;
}

QwtGraphic QwtPlotMultiBarChart::legendIcon( int index,
    const QSizeF &size ) const
{
    QwtColumnRect column;
    column.hInterval = QwtInterval( 0.0, size.width() - 1.0 );
    column.vInterval = QwtInterval( 0.0, size.height() - 1.0 );

    QwtGraphic icon;
    icon.setDefaultSize( size );
    icon.setRenderHint( QwtGraphic::RenderPensUnscaled, true );

    QPainter painter( &icon );
    painter.setRenderHint( QPainter::Antialiasing,
        testRenderHint( QwtPlotItem::RenderAntialiased ) );

    drawBar( &painter, -1, index, column );

    return icon;
}