qwt_plot_barchart.h

/* -*- 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
 *****************************************************************************/

#ifndef QWT_PLOT_BAR_CHART_H
#define QWT_PLOT_BAR_CHART_H

#include "qwt_global.h"
#include "qwt_plot_abstract_barchart.h"
#include "qwt_series_data.h"

class QwtColumnRect;
class QwtColumnSymbol;

/*!
  \brief QwtPlotBarChart displays a series of a values as bars.

  Each bar might be customized individually by implementing
  a specialSymbol(). Otherwise it is rendered using a default symbol.

  Depending on its orientation() the bars are displayed horizontally 
  or vertically. The bars cover the interval between the baseline() 
  and the value.

  By activating the LegendBarTitles mode each sample will have
  its own entry on the legend.

  The most common use case of a bar chart is to display a
  list of y coordinates, where the x coordinate is simply the index
  in the list. But for other situations ( f.e. when values are related
  to dates ) it is also possible to set x coordinates explicitly.

  \sa QwtPlotMultiBarChart, QwtPlotHistogram, QwtPlotCurve::Sticks,
      QwtPlotSeriesItem::orientation(), QwtPlotAbstractBarChart::baseline()
 */
class QWT_EXPORT QwtPlotBarChart:
    public QwtPlotAbstractBarChart, public QwtSeriesStore<QPointF>
{
public:
    /*!
      \brief Legend modes.

      The default setting is QwtPlotBarChart::LegendChartTitle.
      \sa setLegendMode(), legendMode()
    */
    enum LegendMode
    {
        /*! 
          One entry on the legend showing the default symbol
          and the title() of the chart

          \sa QwtPlotItem::title()
         */
        LegendChartTitle,

        /*!
          One entry for each value showing the individual symbol
          of the corresponding bar and the bar title.

          \sa specialSymbol(), barTitle()
         */
        LegendBarTitles
    };

    explicit QwtPlotBarChart( const QString &title = QString::null );
    explicit QwtPlotBarChart( const QwtText &title );

    virtual ~QwtPlotBarChart();

    virtual int rtti() const;

    void setSamples( const QVector<QPointF> & );
    void setSamples( const QVector<double> & );
    void setSamples( QwtSeriesData<QPointF> *series );

    void setSymbol( QwtColumnSymbol * );
    const QwtColumnSymbol *symbol() const;

    void setLegendMode( LegendMode );
    LegendMode legendMode() const;

    virtual void drawSeries( QPainter *painter,
        const QwtScaleMap &xMap, const QwtScaleMap &yMap,
        const QRectF &canvasRect, int from, int to ) const;

    virtual QRectF boundingRect() const;

    virtual QwtColumnSymbol *specialSymbol( 
        int sampleIndex, const QPointF& ) const;

    virtual QwtText barTitle( int sampleIndex ) const;

protected:
    virtual void drawSample( QPainter *painter,
        const QwtScaleMap &xMap, const QwtScaleMap &yMap,
        const QRectF &canvasRect, const QwtInterval &boundingInterval,
        int index, const QPointF& sample ) const;

    virtual void drawBar( QPainter *,
        int sampleIndex, const QPointF& point, 
        const QwtColumnRect & ) const;

    QList<QwtLegendData> legendData() const;
    QwtGraphic legendIcon( int index, const QSizeF & ) const;

private:
    void init();

    class PrivateData;
    PrivateData *d_data;
};

#endif