qwt_vectorfield_symbol.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_VECTOR_FIELD_SYMBOL_H
#define QWT_VECTOR_FIELD_SYMBOL_H
 
#include "qwt_global.h"
 
class QPainter;
class QPainterPath;
 
class QWT_EXPORT QwtVectorFieldSymbol
{
public:
    QwtVectorFieldSymbol();
    virtual ~QwtVectorFieldSymbol();
 
    virtual void setLength(qreal length) = 0;
    virtual qreal length() const = 0;
    virtual void paint(QPainter*) const = 0;
 
private:
    QwtVectorFieldSymbol(const QwtVectorFieldSymbol&)            = delete;
    QwtVectorFieldSymbol& operator=(const QwtVectorFieldSymbol&) = delete;
};
 
class QWT_EXPORT QwtVectorFieldArrow : public QwtVectorFieldSymbol
{
public:
    QwtVectorFieldArrow(qreal headWidth = 6.0, qreal tailWidth = 1.0);
    virtual ~QwtVectorFieldArrow() override;
 
    virtual void setLength(qreal length) override;
    virtual qreal length() const override;
    virtual void paint(QPainter*) const override;
 
private:
    QWT_DECLARE_PRIVATE(QwtVectorFieldArrow)
};
 
class QWT_EXPORT QwtVectorFieldThinArrow : public QwtVectorFieldSymbol
{
public:
    QwtVectorFieldThinArrow(qreal headWidth = 6.0);
    virtual ~QwtVectorFieldThinArrow() override;
 
    virtual void setLength(qreal length) override;
    virtual qreal length() const override;
    virtual void paint(QPainter*) const override;
 
private:
    QWT_DECLARE_PRIVATE(QwtVectorFieldThinArrow)
};
 
#endif