qwt_plot_arrowmarker.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_ARROWMARKER_H
#define QWT_PLOT_ARROWMARKER_H
 
#include "qwt_global.h"
#include "qwt_plot_item.h"
 
class QString;
class QRectF;
class QwtText;
class QPainterPath;
class QPen;
class QBrush;
 
class QWT_EXPORT QwtPlotArrowMarker : public QwtPlotItem
{
public:
    enum EndpointStyle
    {
        NoEndpoint = 0,
 
        ArrowHead,
 
        Circle,
 
        Square,
 
        Diamond,
 
        Triangle,
 
        CustomPath
    };
 
    enum PositionMode
    {
        ExplicitPoints,
 
        StartLengthAngle
    };
 
    // Constructor
    explicit QwtPlotArrowMarker();
 
    // Constructor with title
    explicit QwtPlotArrowMarker(const QString& title);
 
    // Constructor with QwtText title
    explicit QwtPlotArrowMarker(const QwtText& title);
 
    // Destructor
    virtual ~QwtPlotArrowMarker();
 
    // Get the runtime type information
    virtual int rtti() const override;
 
    // Position and geometry methods
 
    // Get the start point
    QPointF startPoint() const;
 
    // Get the end point
    QPointF endPoint() const;
 
    // Set the start point
    void setStartPoint(const QPointF& point);
 
    // Set the end point
    void setEndPoint(const QPointF& point);
 
    // Set both start and end points
    void setPoints(const QPointF& start, const QPointF& end);
 
    // Get the arrow length in pixels
    double length() const;
 
    // Set the arrow length in pixels
    void setLength(double length);
 
    // Get the rotation angle in degrees
    double angle() const;
 
    // Set the rotation angle in degrees
    void setAngle(double angle);
 
    // Get the positioning mode
    PositionMode positionMode() const;
 
    // Set the positioning mode
    void setPositionMode(PositionMode mode);
 
    // Style and appearance methods
 
    // Get the arrow line pen
    const QPen& linePen() const;
 
    // Set the arrow line pen
    void setLinePen(const QPen& pen);
 
    // Convenience method to set line color and width
    void setLinePen(const QColor& color, qreal width = 1.0, Qt::PenStyle style = Qt::SolidLine);
 
    // Get the head style
    EndpointStyle headStyle() const;
 
    // Set the head style
    void setHeadStyle(EndpointStyle style);
 
    // Get the tail style
    EndpointStyle tailStyle() const;
 
    // Set the tail style
    void setTailStyle(EndpointStyle style);
 
    // Get the head size in pixels
    QSizeF headSize() const;
 
    // Set the head size in pixels
    void setHeadSize(const QSizeF& size);
 
    // Convenience method to set head size with equal width and height
    void setHeadSize(qreal size);
 
    // Get the tail size in pixels
    QSizeF tailSize() const;
 
    // Set the tail size in pixels
    void setTailSize(const QSizeF& size);
 
    // Convenience method to set tail size with equal width and height
    void setTailSize(qreal size);
 
    // Get the head brush
    const QBrush& headBrush() const;
 
    // Set the head brush
    void setHeadBrush(const QBrush& brush);
 
    // Get the tail brush
    const QBrush& tailBrush() const;
 
    // Set the tail brush
    void setTailBrush(const QBrush& brush);
 
    // Get the head pen
    const QPen& headPen() const;
 
    // Set the head pen
    void setHeadPen(const QPen& pen);
 
    // Get the tail pen
    const QPen& tailPen() const;
 
    // Set the tail pen
    void setTailPen(const QPen& pen);
 
    // Set a custom path for head endpoint
    void setHeadCustomPath(const QPainterPath& path);
 
    // Get the custom head path
    QPainterPath headCustomPath() const;
 
    // Set a custom path for tail endpoint
    void setTailCustomPath(const QPainterPath& path);
 
    // Get the custom tail path
    QPainterPath tailCustomPath() const;
 
    // Drawing methods
 
    // Draw the arrow marker
    virtual void
    draw(QPainter* painter, const QwtScaleMap& xMap, const QwtScaleMap& yMap, const QRectF& canvasRect) const override;
 
    // Get the bounding rectangle
    virtual QRectF boundingRect() const override;
 
    // Get the legend icon
    virtual QwtGraphic legendIcon(int index, const QSizeF& size) const override;
 
protected:
    virtual void drawArrowLine(QPainter* painter, const QPointF& canvasStart, const QPointF& canvasEnd) const;
    virtual void drawCachedEndpoint(QPainter* painter,
                                    const QPointF& position,
                                    const QPainterPath& cachedPath,
                                    const QSizeF& size,
                                    const QPen& pen,
                                    const QBrush& brush,
                                    double rotation = 0.0) const;
 
    virtual QPointF toCanvasPoint(const QPointF& plotPoint, const QwtScaleMap& xMap, const QwtScaleMap& yMap) const;
 
    virtual QPointF calculateEndPoint() const;
 
private:
    // Disable copy constructor and assignment operator
    QwtPlotArrowMarker(const QwtPlotArrowMarker&);
    QwtPlotArrowMarker& operator=(const QwtPlotArrowMarker&);
 
    class PrivateData;
    PrivateData* m_data;
};
 
#endif  // QWT_PLOT_ARROWMARKER_H