qwt_plot_series_data_picker.h

/******************************************************************************
 * Qwt Widget Library
 * Copyright (C) 2024   ChenZongYan <czy.t@163.com>
 *****************************************************************************/
#ifndef QWT_PLOT_SERIES_DATA_PICKER_H
#define QWT_PLOT_SERIES_DATA_PICKER_H
#include <QList>
#include <QPointF>
#include <QVariant>
#include "qwt_canvas_picker.h"
#include "qwt_text.h"
class QwtPlot;
class QwtPlotItem;
 
class QWT_EXPORT QwtPlotSeriesDataPicker : public QwtCanvasPicker
{
    Q_OBJECT
    QWT_DECLARE_PRIVATE(QwtPlotSeriesDataPicker)
public:
    enum PickSeriesMode
    {
        PickYValue,       
        PickNearestPoint  
    };
 
    enum TextPlacement
    {
        TextPlaceAuto,            
        TextFollowOnTop,          
        TextFollowOnBottom,       
        TextFollowMouse,          
        TextOnCanvasTopRight,     
        TextOnCanvasTopLeft,      
        TextOnCanvasBottomRight,  
        TextOnCanvasBottomLeft,   
        TextOnCanvasTopAuto,      
        TextOnCanvasBottomAuto    
    };
 
    enum InterpolationMode
    {
        NoInterpolation,     
        LinearInterpolation  
    };
 
    struct FeaturePoint
    {
        QwtPlotItem* item { nullptr };  
        QPointF feature { 0, 0 };       
        QVariant sampleData;            
        size_t index { 0 };             
    };
 
public:
    explicit QwtPlotSeriesDataPicker(QWidget* canvas);
    ~QwtPlotSeriesDataPicker() override;
 
    void setPickMode(PickSeriesMode mode);
    PickSeriesMode pickMode() const;
 
    void setTextArea(TextPlacement t);
    TextPlacement textArea() const;
 
    void setInterpolationMode(InterpolationMode mode);
    InterpolationMode interpolationMode() const;
    bool isInterpolation() const;
 
    void setNearestSearchWindowSize(int windowSize);
    int nearestSearchWindowSize() const;
 
    void setEnableDrawFeaturePoint(bool on = true);
    bool isEnableDrawFeaturePoint() const;
 
    void setDrawFeaturePointSize(int px);
    int drawFeaturePointSize() const;
 
    // Returns the list of feature points currently picked by the tracker
    QList< FeaturePoint > featurePoints() const;
 
    void setTextBackgroundBrush(const QBrush& br);
    QBrush textBackgroundBrush() const;
 
    void setTextAlignment(Qt::Alignment al);
    Qt::Alignment textAlignment() const;
 
    void setEnableShowXValue(bool on);
    bool isEnableShowXValue() const;
 
    void setTextTrackerOffset(const QPoint& offset);
    QPoint textTrackerOffset() const;
 
    QwtText trackerText(const QPoint& pos) const override;
 
    QRect trackerRect(const QFont& f) const override;
 
    virtual void drawRubberBand(QPainter* painter) const override;
 
    virtual void setTrackerPosition(const QPoint& pos) override;
 
protected:
    virtual int pickYValue(const QwtPlot* p, const QPoint& pos, bool interpolate = false);
    virtual int pickNearestPoint(const QwtPlot* plot, const QPoint& pos, int windowSize = -5);
 
    virtual void widgetMousePressEvent(QMouseEvent* event) override;
    virtual void widgetMouseDoubleClickEvent(QMouseEvent* event) override;
Q_SIGNALS:
    void clicked(QwtPlotSeriesDataPicker* picker, const QPoint& pos);
 
    void doubleClicked(QwtPlotSeriesDataPicker* picker, const QPoint& pos);
 
private Q_SLOTS:
    // Slot for item detachment, used to update records
    void onPlotItemDetached(QwtPlotItem* item, bool on);
    void onParasitePlotAttached(QwtPlot* parasiteplot, bool on);
 
protected:
    // Generate text content for an item
    virtual QString valueString(const QList< FeaturePoint >& fps) const;
    // Draw a feature point
    virtual void
    drawFeaturePoint(QPainter* painter, const QwtPlot* plot, const QwtPlotItem* item, const QPointF& itemPoint) const;
    // Mouse move
    virtual void move(const QPoint& pos) override;
    // Format value according to axis type; for date axes the value is a large float but users need to see a format like 2024-10-01
    QString formatAxisValue(double value, int axisId, QwtPlot* plot) const;
 
private:
    // Draw feature points (captured points)
    void drawAllFeaturePoints(QPainter* painter) const;
    // Update feature points
    void updateFeaturePoint(const QPoint& pos);
    //
    QRect ensureRectInBounds(const QRect& rect, const QRect& bounds) const;
};
 
#endif  // QWT_PLOT_SERIES_DATA_PICKER_H