qwt_scale_engine.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
 *****************************************************************************/
 
#ifndef QWT_SCALE_ENGINE_H
#define QWT_SCALE_ENGINE_H
 
#include "qwt_global.h"
#include "qwt_scale_div.h"
 
class QwtInterval;
class QwtTransform;
 
class QWT_EXPORT QwtScaleArithmetic
{
  public:
    static double ceilEps( double value, double intervalSize );
    static double floorEps( double value, double intervalSize );
 
    static double divideEps( double intervalSize, double numSteps );
 
    static double divideInterval( double intervalSize,
        int numSteps, uint base );
};
 
class QWT_EXPORT QwtScaleEngine
{
  public:
    enum Attribute
    {
        NoAttribute = 0x00,
 
        IncludeReference = 0x01,
 
        Symmetric = 0x02,
 
        Floating = 0x04,
 
        Inverted = 0x08
    };
 
    Q_DECLARE_FLAGS( Attributes, Attribute )
 
    explicit QwtScaleEngine( uint base = 10 );
    virtual ~QwtScaleEngine();
 
    void setBase( uint base );
    uint base() const;
 
    void setAttribute( Attribute, bool on = true );
    bool testAttribute( Attribute ) const;
 
    void setAttributes( Attributes );
    Attributes attributes() const;
 
    void setReference( double );
    double reference() const;
 
    void setMargins( double lower, double upper );
    double lowerMargin() const;
    double upperMargin() const;
 
    virtual void autoScale( int maxNumSteps,
        double& x1, double& x2, double& stepSize ) const = 0;
 
    virtual QwtScaleDiv divideScale( double x1, double x2,
        int maxMajorSteps, int maxMinorSteps,
        double stepSize = 0.0 ) const = 0;
 
    void setTransformation( QwtTransform* );
    QwtTransform* transformation() const;
 
  protected:
    bool contains( const QwtInterval&, double value ) const;
    QList< double > strip( const QList< double >&, const QwtInterval& ) const;
 
    double divideInterval( double intervalSize, int numSteps ) const;
 
    QwtInterval buildInterval( double value ) const;
 
  private:
    Q_DISABLE_COPY(QwtScaleEngine)
 
    class PrivateData;
    PrivateData* m_data;
};
 
class QWT_EXPORT QwtLinearScaleEngine : public QwtScaleEngine
{
  public:
    explicit QwtLinearScaleEngine( uint base = 10 );
    virtual ~QwtLinearScaleEngine();
 
    virtual void autoScale( int maxNumSteps,
        double& x1, double& x2, double& stepSize ) const QWT_OVERRIDE;
 
    virtual QwtScaleDiv divideScale( double x1, double x2,
        int maxMajorSteps, int maxMinorSteps,
        double stepSize = 0.0 ) const QWT_OVERRIDE;
 
 
  protected:
    QwtInterval align( const QwtInterval&, double stepSize ) const;
 
    void buildTicks(
        const QwtInterval&, double stepSize, int maxMinorSteps,
        QList< double > ticks[QwtScaleDiv::NTickTypes] ) const;
 
    QList< double > buildMajorTicks(
        const QwtInterval& interval, double stepSize ) const;
 
    void buildMinorTicks( const QList< double >& majorTicks,
        int maxMinorSteps, double stepSize,
        QList< double >& minorTicks, QList< double >& mediumTicks ) const;
};
 
class QWT_EXPORT QwtLogScaleEngine : public QwtScaleEngine
{
  public:
    explicit QwtLogScaleEngine( uint base = 10 );
    virtual ~QwtLogScaleEngine();
 
    virtual void autoScale( int maxNumSteps,
        double& x1, double& x2, double& stepSize ) const QWT_OVERRIDE;
 
    virtual QwtScaleDiv divideScale( double x1, double x2,
        int maxMajorSteps, int maxMinorSteps,
        double stepSize = 0.0 ) const QWT_OVERRIDE;
 
  protected:
    QwtInterval align( const QwtInterval&, double stepSize ) const;
 
    void buildTicks(
        const QwtInterval&, double stepSize, int maxMinorSteps,
        QList< double > ticks[QwtScaleDiv::NTickTypes] ) const;
 
    QList< double > buildMajorTicks(
        const QwtInterval& interval, double stepSize ) const;
 
    void buildMinorTicks( const QList< double >& majorTicks,
        int maxMinorSteps, double stepSize,
        QList< double >& minorTicks, QList< double >& mediumTicks ) const;
};
 
Q_DECLARE_OPERATORS_FOR_FLAGS( QwtScaleEngine::Attributes )
 
#endif