qwt_date_scale_engine.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_DATE_SCALE_ENGINE_H
#define QWT_DATE_SCALE_ENGINE_H
 
#include "qwt_global.h"
#include "qwt_date.h"
#include "qwt_scale_engine.h"
 
class QWT_EXPORT QwtDateScaleEngine : public QwtLinearScaleEngine
{
  public:
    explicit QwtDateScaleEngine( Qt::TimeSpec = Qt::LocalTime );
    
    virtual ~QwtDateScaleEngine();
 
    void setTimeSpec( Qt::TimeSpec );
    
    Qt::TimeSpec timeSpec() const;
 
    void setUtcOffset( int seconds );
    
    int utcOffset() const;
 
    void setWeek0Type( QwtDate::Week0Type );
    
    QwtDate::Week0Type week0Type() const;
 
    void setMaxWeeks( int );
    
    int maxWeeks() const;
 
    virtual void autoScale(
        int maxNumSteps, double& x1, double& x2,
        double& stepSize ) const override;
 
    virtual QwtScaleDiv divideScale(
        double x1, double x2,
        int maxMajorSteps, int maxMinorSteps,
        double stepSize = 0.0 ) const override;
 
    virtual QwtDate::IntervalType intervalType(
        const QDateTime&, const QDateTime&, int maxSteps ) const;
 
    QDateTime toDateTime( double ) const;
 
  protected:
    virtual QDateTime alignDate( const QDateTime&, double stepSize,
        QwtDate::IntervalType, bool up ) const;
 
  private:
    QwtScaleDiv buildScaleDiv( const QDateTime&, const QDateTime&,
        int maxMajorSteps, int maxMinorSteps,
        QwtDate::IntervalType ) const;
 
  private:
    class PrivateData;
    PrivateData* m_data;
};
 
#endif