Base class for scale engines 更多...

#include <qwt_scale_engine.h>

类 QwtScaleEngine 继承关系图:

类
class	PrivateData

Public 类型
enum	Attribute { NoAttribute = 0x00 , IncludeReference = 0x01 , Symmetric = 0x02 , Floating = 0x04 , Inverted = 0x08 }
	Layout attributes 更多...

Public 成员函数
	QwtScaleEngine (uint base=10)
	Constructor

void	setBase (uint base)
	Set the base

uint	base () const
	Return base of the scale engine

void	setAttribute (Attribute, bool on=true)
	Set an attribute

bool	testAttribute (Attribute) const
	Test if an attribute is enabled

void	setAttributes (Attributes)
	Set attributes

Attributes	attributes () const
	Return scale attributes

void	setReference (double)
	Set the reference value

double	reference () const
	Return the reference value

void	setMargins (double lower, double upper)
	Set the margins

double	lowerMargin () const
	Return the margin at the lower end of the scale

double	upperMargin () const
	Return the margin at the upper end of the scale

virtual void	autoScale (int maxNumSteps, double &x1, double &x2, double &stepSize) const =0
	Align and divide an interval

virtual QwtScaleDiv	divideScale (double x1, double x2, int maxMajorSteps, int maxMinorSteps, double stepSize=0.0) const =0
	Calculate a scale division

void	setTransformation (QwtTransform *)
	Set the transformation

QwtTransform *	transformation () const
	Create and return a clone of the transformation of the engine

Protected 成员函数
bool	contains (const QwtInterval &, double value) const
	Check if an interval contains a value

QList< double >	strip (const QList< double > &, const QwtInterval &) const
	Strip values outside an interval

double	divideInterval (double intervalSize, int numSteps) const
	Divide an interval

QwtInterval	buildInterval (double value) const
	Build an interval around a value

详细描述

Base class for scale engines

A scale engine tries to find "reasonable" ranges and step sizes for scales. The layout of the scale can be varied with setAttribute(). Qwt offers implementations for logarithmic and linear scales.

参见: QwtLinearScaleEngine, QwtLogScaleEngine

成员枚举类型说明

◆ Attribute

enum QwtScaleEngine::Attribute

Layout attributes

参见: setAttribute(), testAttribute(), reference(), lowerMargin(), upperMargin()

枚举值
NoAttribute	No attributes
IncludeReference	Build a scale which includes the reference() value
Symmetric	Build a scale which is symmetric to the reference() value
Floating	The endpoints of the scale are supposed to be equal the outmost included values plus the specified margins (see setMargins()). If this attribute is not set, the endpoints of the scale will be integer multiples of the step size.
Inverted	Turn the scale upside down

构造及析构函数说明

◆ QwtScaleEngine()

QwtScaleEngine::QwtScaleEngine ( uint base = 10 )

explicit

Constructor

参数

base	Base of the scale engine

参见: setBase()

成员函数说明

◆ attributes()

QwtScaleEngine::Attributes QwtScaleEngine::attributes ( ) const

Return scale attributes

返回: the attributes; Scale attributes

参见: Attribute, setAttributes(), testAttribute()

◆ autoScale()

virtual void QwtScaleEngine::autoScale	(	int	maxNumSteps,
		double &	x1,
		double &	x2,
		double &	stepSize
	)		const

pure virtual

Align and divide an interval

在 QwtLinearScaleEngine, QwtLogScaleEngine , 以及 QwtDateScaleEngine 内被实现.

◆ base()

uint QwtScaleEngine::base ( ) const

Return base of the scale engine

返回: the base; Base of the scale engine

参见: setBase()

◆ buildInterval()

QwtInterval QwtScaleEngine::buildInterval ( double value ) const

protected

Build an interval around a value

In case of v == 0.0 the interval is [-0.5, 0.5], otherwise it is [0.5 * v, 1.5 * v]

参数

value Initial value

返回: Calculated interval

◆ contains()

bool QwtScaleEngine::contains	(	const QwtInterval &	interval,
		double	value
	)		const

protected

Check if an interval contains a value

Check if an interval "contains" a value

参数

interval	Interval
value	Value

返回: True, when the value is inside the interval

◆ divideInterval()

double QwtScaleEngine::divideInterval	(	double	intervalSize,
		int	numSteps
	)		const

protected

Divide an interval

Calculate a step size for an interval size

参数

intervalSize	Interval size
numSteps	Number of steps

返回: Step size

◆ divideScale()

virtual QwtScaleDiv QwtScaleEngine::divideScale	(	double	x1,
		double	x2,
		int	maxMajorSteps,
		int	maxMinorSteps,
		double	stepSize = `0.0`
	)		const

pure virtual

Calculate a scale division

在 QwtLinearScaleEngine, QwtLogScaleEngine , 以及 QwtDateScaleEngine 内被实现.

◆ lowerMargin()

double QwtScaleEngine::lowerMargin ( ) const

Return the margin at the lower end of the scale

返回: the lower margin; The margin at the lower end

The default margin is 0.

参见: setMargins()

◆ reference()

double QwtScaleEngine::reference ( ) const

Return the reference value

返回: the reference value; The reference value

参见: setReference(), setAttribute()

◆ setAttribute()

void QwtScaleEngine::setAttribute	(	Attribute	attribute,
		bool	on = `true`
	)

Set an attribute

Change a scale attribute

参数

attribute	Attribute to change
on	On/Off

参见: Attribute, testAttribute()

◆ setAttributes()

void QwtScaleEngine::setAttributes ( Attributes attributes )

Set attributes

Change the scale attribute

参数

attributes Set scale attributes

参见: Attribute, attributes()

◆ setBase()

void QwtScaleEngine::setBase ( uint base )

Set the base

Set the base of the scale engine

参数

base	Base of the engine

While a base of 10 is what 99.9% of all applications need, certain scales might need a different base: f.e 2. The default setting is 10.

参见: base()

◆ setMargins()

void QwtScaleEngine::setMargins	(	double	lower,
		double	upper
	)

Set the margins

Specify margins at the scale's endpoints

参数

lower	Minimum distance between the scale's lower boundary and the smallest enclosed value
upper	Minimum distance between the scale's upper boundary and the greatest enclosed value

Margins can be used to leave a minimum amount of space between the enclosed intervals and the boundaries of the scale.

警告: QwtLogScaleEngine measures the margins in decades.

参见: upperMargin(), lowerMargin()

◆ setReference()

void QwtScaleEngine::setReference ( double reference )

Set the reference value

Specify a reference point

参数

reference New reference value

The reference point is needed if options IncludeReference or Symmetric are active. Its default value is 0.0.

参见: Attribute

◆ setTransformation()

void QwtScaleEngine::setTransformation ( QwtTransform * transform )

Set the transformation

Assign a transformation

参数

transform Transformation

The transformation object is used as factory for clones that are returned by transformation(). The scale engine takes ownership of the transformation.

参见: QwtTransform::copy(), transformation()

◆ strip()

QList< double > QwtScaleEngine::strip	(	const QList< double > &	ticks,
		const QwtInterval &	interval
	)		const

protected

Strip values outside an interval

Remove ticks from a list, that are not inside an interval

参数

ticks	Tick list
interval	Interval

返回: Stripped tick list

◆ testAttribute()

bool QwtScaleEngine::testAttribute ( Attribute attribute ) const

Test if an attribute is enabled

返回: true if an attribute is set

参数

attribute Attribute to be tested

返回: True, if attribute is enabled

参见: Attribute, setAttribute()

◆ transformation()

QwtTransform * QwtScaleEngine::transformation ( ) const

Create and return a clone of the transformation of the engine

返回: the transformation

When the engine has no special transformation nullptr is returned, indicating no transformation.

返回: A clone of the transformation

参见: setTransformation()

◆ upperMargin()

double QwtScaleEngine::upperMargin ( ) const

Return the margin at the upper end of the scale

返回: the upper margin; The margin at the upper end

The default margin is 0.

参见: setMargins()

该类的文档由以下文件生成:

/home/runner/work/QWT/QWT/src/core/qwt_scale_engine.h
/home/runner/work/QWT/QWT/src/core/qwt_scale_engine.cpp

类

Public 类型

Public 成员函数

Protected 成员函数

详细描述

成员枚举类型说明

◆ Attribute

构造及析构函数说明

◆ QwtScaleEngine()

成员函数说明

◆ attributes()

◆ autoScale()

◆ base()

◆ buildInterval()

◆ contains()

◆ divideInterval()

◆ divideScale()

◆ lowerMargin()

◆ reference()

◆ setAttribute()

◆ setAttributes()

◆ setBase()

◆ setMargins()

◆ setReference()

◆ setTransformation()

◆ strip()

◆ testAttribute()

◆ transformation()

◆ upperMargin()