qwt_plot_abstract_barchart.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_ABSTRACT_BAR_CHART_H
#define QWT_PLOT_ABSTRACT_BAR_CHART_H
 
#include "qwt_global.h"
#include "qwt_plot_seriesitem.h"
 
class QWT_EXPORT QwtPlotAbstractBarChart : public QwtPlotSeriesItem
{
public:
    enum LayoutPolicy
    {
        AutoAdjustSamples,
 
        ScaleSamplesToAxes,
 
        ScaleSampleToCanvas,
 
        FixedSampleSize
    };
 
    // Constructor with title
    explicit QwtPlotAbstractBarChart(const QwtText& title);
    // Destructor
    ~QwtPlotAbstractBarChart() override;
 
    // Set the layout policy for bar width calculation
    void setLayoutPolicy(LayoutPolicy);
    // Get the layout policy
    LayoutPolicy layoutPolicy() const;
 
    // Set the layout hint for bar width calculation
    void setLayoutHint(double);
    // Get the layout hint
    double layoutHint() const;
 
    // Set the spacing between bars
    void setSpacing(int);
    // Get the spacing between bars
    int spacing() const;
 
    // Set the margin around the bars
    void setMargin(int);
    // Get the margin around the bars
    int margin() const;
 
    // Set the baseline value for the bars
    void setBaseline(double);
    // Get the baseline value
    double baseline() const;
 
    // Calculate canvas margin hint for layout
    virtual void getCanvasMarginHint(const QwtScaleMap& xMap,
                                     const QwtScaleMap& yMap,
                                     const QRectF& canvasRect,
                                     double& left,
                                     double& top,
                                     double& right,
                                     double& bottom) const override;
 
protected:
    double sampleWidth(const QwtScaleMap& map, double canvasSize, double boundingSize, double value) const;
 
private:
    QWT_DECLARE_PRIVATE(QwtPlotAbstractBarChart)
};
 
#endif