qwt_compass.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_COMPASS_H
#define QWT_COMPASS_H
 
#include "qwt_global.h"
#include "qwt_dial.h"
#include "qwt_round_scale_draw.h"
 
class QwtCompassRose;
class QString;
template< class Key, class T >
class QMap;
 
class QWT_EXPORT QwtCompassScaleDraw : public QwtRoundScaleDraw
{
public:
    // Constructs a compass scale draw with default label map (N, NE, E, SE, S, SW, W, NW)
    explicit QwtCompassScaleDraw();
    // Constructs a compass scale draw with a custom label map
    explicit QwtCompassScaleDraw(const QMap< double, QString >& map);
 
    // Destructor
    ~QwtCompassScaleDraw() override;
 
    // Sets the map that maps values to labels
    void setLabelMap(const QMap< double, QString >& map);
    // Returns the map that maps values to labels
    QMap< double, QString > labelMap() const;
 
    // Returns the label for a given value by looking up the label map
    virtual QwtText label(double value) const override;
 
private:
    QWT_DECLARE_PRIVATE(QwtCompassScaleDraw)
};
 
class QWT_EXPORT QwtCompass : public QwtDial
{
    Q_OBJECT
 
public:
    // Constructs a compass widget with a scale, no needle and no rose
    explicit QwtCompass(QWidget* parent = nullptr);
    // Destructor
    ~QwtCompass() override;
 
    // Sets a compass rose that will be drawn inside the compass
    void setRose(QwtCompassRose* rose);
    // Returns the compass rose (const version)
    const QwtCompassRose* rose() const;
    // Returns the compass rose
    QwtCompassRose* rose();
 
protected:
    virtual void drawRose(QPainter*, const QPointF& center, double radius, double north, QPalette::ColorGroup) const;
 
    virtual void drawScaleContents(QPainter*, const QPointF& center, double radius) const override;
 
    virtual void keyPressEvent(QKeyEvent*) override;
 
private:
    QWT_DECLARE_PRIVATE(QwtCompass)
};
 
#endif