Qwt User's Guide: QwtLinearScaleEngine Class Reference

Qwt User's Guide 6.3.0

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Public Member Functions | Protected Member Functions | List of all members
QwtLinearScaleEngine Class Reference

A scale engine for linear scales. More...

`#include <qwt_scale_engine.h>`

Inheritance diagram for QwtLinearScaleEngine:

## Public Member Functions
| QwtLinearScaleEngine (uint base=10)
virtual | ~QwtLinearScaleEngine ()
| Destructor.
virtual void | autoScale (int maxNumSteps, double &x1, double &x2, double &stepSize) const override
virtual QwtScaleDiv | divideScale (double x1, double x2, int maxMajorSteps, int maxMinorSteps, double stepSize=0.0) const override
| Calculate a scale division for an interval.
Public Member Functions inherited from QwtScaleEngine
| QwtScaleEngine (uint base=10)
virtual | ~QwtScaleEngine ()
| Destructor.
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)
| Specify a reference point.
double | reference () const
void | setMargins (double lower, double upper)
| Specify margins at the scale's endpoints.
double | lowerMargin () const
double | upperMargin () const
void | setTransformation (QwtTransform *)
QwtTransform * | transformation () const

## Protected Member Functions
QwtInterval | align (const QwtInterval &, double stepSize) const
| Align an interval to a step size.
void | buildTicks (const QwtInterval &, double stepSize, int maxMinorSteps, QList< double > ticks[QwtScaleDiv::NTickTypes]) const
| Calculate ticks for an interval.
QList< double > | buildMajorTicks (const QwtInterval &interval, double stepSize) const
| Calculate major ticks for an interval.
void | buildMinorTicks (const QList< double > &majorTicks, int maxMinorSteps, double stepSize, QList< double > &minorTicks, QList< double > &mediumTicks) const
| Calculate minor/medium ticks for major ticks.
Protected Member Functions inherited from QwtScaleEngine
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
| Build an interval around a value.

## Additional Inherited Members
Public Types inherited from QwtScaleEngine
enum | Attribute { NoAttribute = 0x00 , IncludeReference = 0x01 , Symmetric = 0x02 , Floating = 0x04 , Inverted = 0x08 }
typedef QFlags< Attribute > | Attributes

## Detailed Description

A scale engine for linear scales.

The step size will fit into the pattern , where n is an integer.

Definition at line 151 of file qwt_scale_engine.h.

## Constructor & Destructor Documentation

## ◆ QwtLinearScaleEngine()

QwtLinearScaleEngine::QwtLinearScaleEngine | ( | uint | base = 10 | ) |
| explicit

Constructor

Parameters

  base | Base of the scale engine

See also
  setBase()

Definition at line 511 of file qwt_scale_engine.cpp.

## ◆ ~QwtLinearScaleEngine()

QwtLinearScaleEngine::~QwtLinearScaleEngine | ( |  | ) |
| virtual

Destructor.

Definition at line 517 of file qwt_scale_engine.cpp.

## Member Function Documentation

## ◆ align()

QwtInterval QwtLinearScaleEngine::align | ( | const QwtInterval & | interval,
|  | double | stepSize ) const
| protected

Align an interval to a step size.

The limits of an interval are aligned that both are integer multiples of the step size.

Parameters

  interval | Interval
  stepSize | Step size

Returns
  Aligned interval

Definition at line 741 of file qwt_scale_engine.cpp.

## ◆ autoScale()

void QwtLinearScaleEngine::autoScale | ( | int | maxNumSteps,
|  | double & | x1,
|  | double & | x2,
|  | double & | stepSize ) const
| overridevirtual

Align and divide an interval

Parameters

  maxNumSteps | Max. number of steps
  x1 | First limit of the interval (In/Out)
  x2 | Second limit of the interval (In/Out)
  stepSize | Step size (Out)

See also
  setAttribute()

Implements QwtScaleEngine.

Reimplemented in QwtDateScaleEngine.

Definition at line 531 of file qwt_scale_engine.cpp.

## ◆ buildMajorTicks()

QList< double > QwtLinearScaleEngine::buildMajorTicks | ( | const QwtInterval & | interval,
|  | double | stepSize ) const
| protected

Calculate major ticks for an interval.

Parameters

  interval | Interval
  stepSize | Step size

Returns
  Calculated ticks

Definition at line 664 of file qwt_scale_engine.cpp.

## ◆ buildMinorTicks()

void QwtLinearScaleEngine::buildMinorTicks | ( | const QList< double > & | majorTicks,
|  | int | maxMinorSteps,
|  | double | stepSize,
|  | QList< double > & | minorTicks,
|  | QList< double > & | mediumTicks ) const
| protected

Calculate minor/medium ticks for major ticks.

Parameters

  majorTicks | Major ticks
  maxMinorSteps | Maximum number of minor steps
  stepSize | Step size
  minorTicks | Array to be filled with the calculated minor ticks
  mediumTicks | Array to be filled with the calculated medium ticks

Definition at line 692 of file qwt_scale_engine.cpp.

## ◆ buildTicks()

void QwtLinearScaleEngine::buildTicks | ( | const QwtInterval & | interval,
|  | double | stepSize,
|  | int | maxMinorSteps,
|  | QList< double > | ticks[QwtScaleDiv::NTickTypes] ) const
| protected

Calculate ticks for an interval.

Parameters

  interval | Interval
  stepSize | Step size
  maxMinorSteps | Maximum number of minor steps
  ticks | Arrays to be filled with the calculated ticks

See also
  buildMajorTicks(), buildMinorTicks

Definition at line 627 of file qwt_scale_engine.cpp.

## ◆ divideScale()

QwtScaleDiv QwtLinearScaleEngine::divideScale | ( | double | x1,
|  | double | x2,
|  | int | maxMajorSteps,
|  | int | maxMinorSteps,
|  | double | stepSize = 0.0 ) const
| overridevirtual

Calculate a scale division for an interval.

Parameters

  x1 | First interval limit
  x2 | Second interval limit
  maxMajorSteps | Maximum for the number of major steps
  maxMinorSteps | Maximum number of minor steps
  stepSize | Step size. If stepSize == 0, the engine calculates one.

Returns
  Calculated scale division

Implements QwtScaleEngine.

Reimplemented in QwtDateScaleEngine.

Definition at line 577 of file qwt_scale_engine.cpp.