qwt_plot_histogram.h

/******************************************************************************
 * 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
 *
 * Modified by ChenZongYan in 2024 <czy.t@163.com>
 *   Summary of major modifications (see ChangeLog.md for full history):
 *   1. CMake build system & C++11 throughout.
 *   2. Core panner/ zoomer refactored:
 *        - QwtPanner → QwtCachePanner (pixmap-cache version)
 *        - New real-time QwtPlotPanner derived from QwtPicker.
 *   3. Zoomer supports multi-axis.
 *   4. Parasite-plot framework:
 *        - QwtFigure, QwtPlotParasiteLayout, QwtPlotTransparentCanvas,
 *        - QwtPlotScaleEventDispatcher, built-in pan/zoom on axis.
 *   5. New picker: QwtPlotSeriesDataPicker (works with date axis).
 *   6. Raster & color-map extensions:
 *        - QwtGridRasterData (2-D table + interpolation)
 *        - QwtLinearColorMap::stopColors(), stopPos() API rename.
 *   7. Bar-chart: expose pen/brush control.
 *   8. Amalgamated build: single QwtPlot.h / QwtPlot.cpp pair in src-amalgamate.
 *****************************************************************************/
 
#ifndef QWT_PLOT_HISTOGRAM_H
#define QWT_PLOT_HISTOGRAM_H
 
#include "qwt_global.h"
#include "qwt_plot_seriesitem.h"
 
class QwtColumnSymbol;
class QwtColumnRect;
class QColor;
class QPolygonF;
 
#if QT_VERSION < 0x060000
template< typename T > class QVector;
#endif
 
class QWT_EXPORT QwtPlotHistogram
    : public QwtPlotSeriesItem
    , public QwtSeriesStore< QwtIntervalSample >
{
  public:
    enum HistogramStyle
    {
        Outline,
 
        Columns,
 
        Lines,
 
        UserStyle = 100
    };
 
    // Constructor
explicit QwtPlotHistogram( const QString& title = QString() );
 
    // Constructor with QwtText title
explicit QwtPlotHistogram( const QwtText& title );
 
    // Destructor
virtual ~QwtPlotHistogram();
 
    // Get the runtime type information
virtual int rtti() const override;
 
    // Set pen
void setPen( const QColor&,
    qreal width = 0.0, Qt::PenStyle = Qt::SolidLine );
 
    // Set pen
void setPen( const QPen& );
 
    // Get pen
const QPen& pen() const;
 
    // Set brush
void setBrush( const QBrush& );
 
    // Get brush
const QBrush& brush() const;
 
    // Set samples from a vector
void setSamples( const QVector< QwtIntervalSample >& );
 
    // Set samples from a series data
void setSamples( QwtSeriesData< QwtIntervalSample >* );
 
    // Set baseline
void setBaseline( double );
 
    // Get baseline
double baseline() const;
 
    // Set histogram style
void setStyle( HistogramStyle style );
 
    // Get histogram style
HistogramStyle style() const;
 
    // Set symbol
void setSymbol( const QwtColumnSymbol* );
 
    // Get symbol
const QwtColumnSymbol* symbol() const;
 
    // Draw the series
virtual void drawSeries( QPainter*,
    const QwtScaleMap& xMap, const QwtScaleMap& yMap,
    const QRectF& canvasRect, int from, int to ) const override;
 
    // Get the bounding rectangle
virtual QRectF boundingRect() const override;
 
    // Get the legend icon
virtual QwtGraphic legendIcon(
    int index, const QSizeF& ) const override;
 
  protected:
virtual QwtColumnRect columnRect( const QwtIntervalSample&,
    const QwtScaleMap&, const QwtScaleMap& ) const;
 
virtual void drawColumn( QPainter*, const QwtColumnRect&,
    const QwtIntervalSample& ) const;
 
void drawColumns( QPainter*,
    const QwtScaleMap& xMap, const QwtScaleMap& yMap,
    int from, int to ) const;
 
void drawOutline( QPainter*,
    const QwtScaleMap& xMap, const QwtScaleMap& yMap,
    int from, int to ) const;
 
void drawLines( QPainter*,
    const QwtScaleMap& xMap, const QwtScaleMap& yMap,
    int from, int to ) const;
 
  private:
void init();
 
void flushPolygon( QPainter*, double baseLine, QPolygonF& ) const;
 
    class PrivateData;
    PrivateData* m_data;
};
 
#endif