qwt_picker.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_PICKER
#define QWT_PICKER
 
#include "qwt_global.h"
#include "qwt_event_pattern.h"
 
#include <qobject.h>
#include <QPen>
#include <QFont>
#include <QPainterPath>
#include <QPoint>
#include <QPolygon>
#include <QSize>
#include <QRect>
#include <QRegion>
class QwtPickerMachine;
class QwtWidgetOverlay;
class QwtText;
class QWidget;
class QMouseEvent;
class QWheelEvent;
class QKeyEvent;
class QPainter;
 
class QWT_EXPORT QwtPicker : public QObject, public QwtEventPattern
{
    Q_OBJECT
 
    Q_ENUMS(RubberBand DisplayMode ResizeMode)
 
    Q_PROPERTY(bool isEnabled READ isEnabled WRITE setEnabled)
    Q_PROPERTY(ResizeMode resizeMode READ resizeMode WRITE setResizeMode)
 
    Q_PROPERTY(DisplayMode trackerMode READ trackerMode WRITE setTrackerMode)
    Q_PROPERTY(QPen trackerPen READ trackerPen WRITE setTrackerPen)
    Q_PROPERTY(QFont trackerFont READ trackerFont WRITE setTrackerFont)
 
    Q_PROPERTY(RubberBand rubberBand READ rubberBand WRITE setRubberBand)
    Q_PROPERTY(QPen rubberBandPen READ rubberBandPen WRITE setRubberBandPen)
    QWT_DECLARE_PRIVATE(QwtPicker)
public:
    enum RubberBand
    {
        NoRubberBand = 0,
 
        HLineRubberBand,
 
        VLineRubberBand,
 
        CrossRubberBand,
 
        RectRubberBand,
 
        EllipseRubberBand,
 
        PolygonRubberBand,
 
        UserRubberBand = 100
    };
 
    enum DisplayMode
    {
        AlwaysOff,
 
        AlwaysOn,
 
        ActiveOnly
    };
 
    enum ResizeMode
    {
        Stretch,
 
        KeepSize
    };
 
    // Constructor
    explicit QwtPicker(QWidget* parent);
    // Constructor with rubber band and tracker mode
    explicit QwtPicker(RubberBand rubberBand, DisplayMode trackerMode, QWidget*);
 
    // Destructor
    virtual ~QwtPicker();
 
    // Set the state machine
    void setStateMachine(QwtPickerMachine*);
    // Return the state machine (const)
    const QwtPickerMachine* stateMachine() const;
    // Return the state machine
    QwtPickerMachine* stateMachine();
 
    // Set the rubber band style
    void setRubberBand(RubberBand);
    // Return the rubber band style
    RubberBand rubberBand() const;
 
    // Set the tracker display mode
    void setTrackerMode(DisplayMode);
    // Return the tracker display mode
    DisplayMode trackerMode() const;
 
    // Set the resize mode
    void setResizeMode(ResizeMode);
    // Return the resize mode
    ResizeMode resizeMode() const;
 
    // Set the rubber band pen
    void setRubberBandPen(const QPen&);
    // Return the rubber band pen
    QPen rubberBandPen() const;
 
    // Set the tracker pen
    void setTrackerPen(const QPen&);
    // Return the tracker pen
    QPen trackerPen() const;
 
    // Set the tracker font
    void setTrackerFont(const QFont&);
    // Return the tracker font
    QFont trackerFont() const;
 
    // Return true when enabled
    bool isEnabled() const;
    // Return true if the selection is active
    bool isActive() const;
 
    // Event filter for handling events
    virtual bool eventFilter(QObject*, QEvent*) override;
 
    // Return the parent widget
    QWidget* parentWidget();
    // Return the parent widget (const)
    const QWidget* parentWidget() const;
 
    // Return the pick area
    virtual QPainterPath pickArea() const;
 
    // Draw the rubber band
    virtual void drawRubberBand(QPainter*) const;
    // Draw the tracker
    virtual void drawTracker(QPainter*) const;
 
    // Return the tracker mask
    virtual QRegion trackerMask() const;
    // Return the rubber band mask
    virtual QRegion rubberBandMask() const;
 
    // Return the tracker text for a position
    virtual QwtText trackerText(const QPoint& pos) const;
    // Return the tracker rectangle
    virtual QRect trackerRect(const QFont&) const;
    // Set the tracker position manually (for displaying picker without mouse)
    virtual void setTrackerPosition(const QPoint& pos);
    // Return the tracker position
    QPoint trackerPosition() const;
    // Return the selected points
    QPolygon selection() const;
    // Update the display
    void update();
    // Set the picker active manually
    void setActive(bool on);
public Q_SLOTS:
    // Enable or disable the picker
    void setEnabled(bool);
 
Q_SIGNALS:
    void activated(bool on);
 
    void selected(const QPolygon& polygon);
 
    void appended(const QPoint& pos);
 
    void moved(const QPoint& pos);
 
    void removed(const QPoint& pos);
 
    void changed(const QPolygon& selection);
 
protected:
    virtual QPolygon adjustedPoints(const QPolygon&) const;
 
    virtual void transition(const QEvent*);
 
    virtual void begin();
    virtual void append(const QPoint&);
    virtual void move(const QPoint&);
    virtual void remove();
    virtual bool end(bool ok = true);
 
    virtual bool accept(QPolygon&) const;
    virtual void reset();
 
    virtual void widgetMousePressEvent(QMouseEvent*);
    virtual void widgetMouseReleaseEvent(QMouseEvent*);
    virtual void widgetMouseDoubleClickEvent(QMouseEvent*);
    virtual void widgetMouseMoveEvent(QMouseEvent*);
    virtual void widgetWheelEvent(QWheelEvent*);
    virtual void widgetKeyPressEvent(QKeyEvent*);
    virtual void widgetKeyReleaseEvent(QKeyEvent*);
    virtual void widgetEnterEvent(QEvent*);
    virtual void widgetLeaveEvent(QEvent*);
 
    virtual void stretchSelection(const QSize& oldSize, const QSize& newSize);
 
    virtual void updateDisplay();
 
    const QwtWidgetOverlay* rubberBandOverlay() const;
    const QwtWidgetOverlay* trackerOverlay() const;
 
    const QPolygon& pickedPoints() const;
 
private:
    void init(QWidget*, RubberBand rubberBand, DisplayMode trackerMode);
 
    void setMouseTracking(bool);
};
 
#endif