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
    ~QwtPlotHistogram() override;
 
    // Get the runtime type information
    virtual int rtti() const override;
 
    // Attach the histogram to a plot (applies color cycle if pen/brush not user-set)
    void attach(QwtPlot* plot) 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;
 
    QWT_DECLARE_PRIVATE(QwtPlotHistogram)
};
 
#endif