qwt_picker_machine.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_MACHINE
#define QWT_PICKER_MACHINE
 
#include "qwt_global.h"
 
class QwtEventPattern;
class QEvent;
template< typename T > class QList;
 
class QWT_EXPORT QwtPickerMachine
{
  public:
    enum SelectionType
    {
        NoSelection = -1,
 
        PointSelection,
 
        RectSelection,
 
        PolygonSelection
    };
 
    enum Command
    {
        Begin,
        Append,
        Move,
        Remove,
        End
    };
 
    // Constructor with selection type
    explicit QwtPickerMachine( SelectionType );
    // Destructor
    virtual ~QwtPickerMachine();
 
    // Transition function that processes events and returns commands
    virtual QList< Command > transition(
        const QwtEventPattern&, const QEvent* ) = 0;
    // Reset the state machine to initial state
    void reset();
 
    // Return the current state
    int state() const;
    // Set the current state
    void setState( int );
 
    // Return the selection type
    SelectionType selectionType() const;
 
  private:
    const SelectionType m_selectionType;
    int m_state;
};
 
class QWT_EXPORT QwtPickerTrackerMachine : public QwtPickerMachine
{
  public:
    // Constructor
    QwtPickerTrackerMachine();
 
    // Transition function for tracking mouse movements
    virtual QList< Command > transition(
        const QwtEventPattern&, const QEvent* ) override;
};
 
class QWT_EXPORT QwtPickerClickPointMachine : public QwtPickerMachine
{
  public:
    // Constructor
    QwtPickerClickPointMachine();
 
    // Transition function for click point selection
    virtual QList< Command > transition(
        const QwtEventPattern&, const QEvent* ) override;
};
 
class QWT_EXPORT QwtPickerDragPointMachine : public QwtPickerMachine
{
  public:
    // Constructor
    QwtPickerDragPointMachine();
 
    // Transition function for drag point selection
    virtual QList< Command > transition(
        const QwtEventPattern&, const QEvent* ) override;
};
 
class QWT_EXPORT QwtPickerClickRectMachine : public QwtPickerMachine
{
  public:
    // Constructor
    QwtPickerClickRectMachine();
 
    // Transition function for click rectangle selection
    virtual QList< Command > transition(
        const QwtEventPattern&, const QEvent* ) override;
};
 
class QWT_EXPORT QwtPickerDragRectMachine : public QwtPickerMachine
{
  public:
    // Constructor
    QwtPickerDragRectMachine();
 
    // Transition function for drag rectangle selection
    virtual QList< Command > transition(
        const QwtEventPattern&, const QEvent* ) override;
};
 
class QWT_EXPORT QwtPickerDragLineMachine : public QwtPickerMachine
{
  public:
    // Constructor
    QwtPickerDragLineMachine();
 
    // Transition function for drag line selection
    virtual QList< Command > transition(
        const QwtEventPattern&, const QEvent* ) override;
};
 
class QWT_EXPORT QwtPickerPolygonMachine : public QwtPickerMachine
{
  public:
    // Constructor
    QwtPickerPolygonMachine();
 
    // Transition function for polygon selection
    virtual QList< Command > transition(
        const QwtEventPattern&, const QEvent* ) override;
};
 
#endif