An abstract base class for widgets having a scale. More...

#include <qwt_abstract_scale.h>

Inheritance diagram for QwtAbstractScale:

Classes
class	PrivateData

Public Member Functions
	QwtAbstractScale (QWidget *parent=nullptr)
	Constructor for QwtAbstractScale.

void	setScale (double lowerBound, double upperBound)
	Specify a scale by interval bounds.

void	setScale (const QwtInterval &)
	Specify a scale by interval.

void	setScale (const QwtScaleDiv &)
	Specify a scale by scale division.

const QwtScaleDiv &	scaleDiv () const
	Return the scale division.

void	setLowerBound (double value)
	Set the lower bound of the scale.

double	lowerBound () const
	Return the lower bound of the scale.

void	setUpperBound (double value)
	Set the upper bound of the scale.

double	upperBound () const
	Return the upper bound of the scale.

void	setScaleStepSize (double stepSize)
	Set the step size used for calculating scale division.

double	scaleStepSize () const
	Return the step size hint.

void	setScaleMaxMajor (int ticks)
	Set the maximum number of major tick intervals.

int	scaleMaxMinor () const
	Return the maximum number of minor tick intervals.

void	setScaleMaxMinor (int ticks)
	Set the maximum number of minor tick intervals.

int	scaleMaxMajor () const
	Return the maximum number of major tick intervals.

void	setScaleEngine (QwtScaleEngine *)
	Set the scale engine.

const QwtScaleEngine *	scaleEngine () const
	Return the scale engine (const version)

QwtScaleEngine *	scaleEngine ()
	Return the scale engine (non-const version)

int	transform (double) const
	Transform a scale value to widget coordinates.

double	invTransform (int) const
	Transform a widget coordinate to scale value.

bool	isInverted () const
	Check if scale is inverted.

double	minimum () const
	Return the minimum boundary.

double	maximum () const
	Return the maximum boundary.

const QwtScaleMap &	scaleMap () const
	Return the scale map.

Protected Member Functions
virtual void	changeEvent (QEvent *) override
	Handle change events (English only)

void	rescale (double lowerBound, double upperBound, double stepSize)
	Recalculate scale and update scale draw (English only)

void	setAbstractScaleDraw (QwtAbstractScaleDraw *)
	Set the scale draw object (English only)

const QwtAbstractScaleDraw *	abstractScaleDraw () const
	Return the scale draw (const version) (English only)

QwtAbstractScaleDraw *	abstractScaleDraw ()
	Return the scale draw (non-const version) (English only)

void	updateScaleDraw ()
	Update the scale draw (English only)

virtual void	scaleChange ()
	Notify about scale changes (English only)

Properties
double	lowerBound

double	upperBound

int	scaleMaxMajor

int	scaleMaxMinor

double	scaleStepSize

Detailed Description

An abstract base class for widgets having a scale.

The scale of an QwtAbstractScale is determined by a QwtScaleDiv definition that contains the boundaries and the ticks of the scale. The scale is painted using a QwtScaleDraw object. The scale division might be assigned explicitly - but usually it is calculated from the boundaries using a QwtScaleEngine. The scale engine also decides the type of transformation of the scale (linear, logarithmic ...).

Constructor & Destructor Documentation

◆ QwtAbstractScale()

QwtAbstractScale::QwtAbstractScale ( QWidget * parent = nullptr )

explicit

Constructor for QwtAbstractScale.

Parameters

parent Parent widget

Creates a default QwtScaleDraw and a QwtLinearScaleEngine. The initial scale boundaries are set to [ 0.0, 100.0 ] The scaleStepSize() is initialized to 0.0, scaleMaxMajor() to 5 and scaleMaxMinor to 3.

Destructor for QwtAbstractScale

Member Function Documentation

◆ abstractScaleDraw() [1/2]

QwtAbstractScaleDraw * QwtAbstractScale::abstractScaleDraw ( )

protected

Return the scale draw (non-const version) (English only)

Return the scale draw object (non-const)

Returns: Scale draw object

See also: setAbstractScaleDraw()

◆ abstractScaleDraw() [2/2]

const QwtAbstractScaleDraw * QwtAbstractScale::abstractScaleDraw ( ) const

protected

Return the scale draw (const version) (English only)

Return the scale draw object (const)

Returns: Scale draw object

See also: setAbstractScaleDraw()

◆ changeEvent()

void QwtAbstractScale::changeEvent ( QEvent * event )

overrideprotectedvirtual

Handle change events (English only)

Handle change events.

Parameters

event Change event

Invalidates internal caches if necessary (e.g., on locale change).

Reimplemented in QwtDial, QwtKnob, QwtSlider, and QwtThermo.

◆ invTransform()

double QwtAbstractScale::invTransform ( int value ) const

Transform a widget coordinate to scale value.

Parameters

value Widget coordinate

Returns: Corresponding scale coordinate for value

See also: scaleMap(), transform()

◆ isInverted()

bool QwtAbstractScale::isInverted ( ) const

Check if scale is inverted.

Returns: True if scale is increasing in opposite direction to widget coordinates

◆ lowerBound()

double QwtAbstractScale::lowerBound ( ) const

Return the lower bound of the scale.

Returns: Lower bound value

See also: setLowerBound(), setScale(), upperBound()

◆ maximum()

double QwtAbstractScale::maximum ( ) const

Return the maximum boundary.

Returns: The boundary with the larger value

See also: minimum(), lowerBound(), upperBound()

◆ minimum()

double QwtAbstractScale::minimum ( ) const

Return the minimum boundary.

Returns: The boundary with the smaller value

See also: maximum(), lowerBound(), upperBound()

◆ rescale()

void QwtAbstractScale::rescale	(	double	lowerBound,
		double	upperBound,
		double	stepSize
	)

protected

Recalculate scale and update scale draw (English only)

Recalculate scale division and update scale.

Parameters

lowerBound	Lower limit of the scale interval
upperBound	Upper limit of the scale interval
stepSize	Major step size

See also: scaleChange()

◆ scaleChange()

void QwtAbstractScale::scaleChange ( )

protectedvirtual

Notify about scale changes (English only)

Notify about scale changes.

This virtual function is called when the scale changes. Override this function in derived classes to handle scale changes.

Reimplemented in QwtAbstractSlider, QwtDial, QwtSlider, and QwtThermo.

◆ scaleDiv()

const QwtScaleDiv & QwtAbstractScale::scaleDiv ( ) const

Return the scale division.

Returns: Scale boundaries and positions of the ticks

The scale division might have been assigned explicitly or calculated implicitly by rescale().

◆ scaleEngine() [1/2]

QwtScaleEngine * QwtAbstractScale::scaleEngine ( )

Return the scale engine (non-const version)

Returns: Scale engine object

See also: setScaleEngine()

◆ scaleEngine() [2/2]

const QwtScaleEngine * QwtAbstractScale::scaleEngine ( ) const

Return the scale engine (const version)

Returns: Scale engine object

See also: setScaleEngine()

◆ scaleMap()

const QwtScaleMap & QwtAbstractScale::scaleMap ( ) const

Return the scale map.

Returns: Map to translate between scale and widget coordinates

◆ scaleMaxMajor()

int QwtAbstractScale::scaleMaxMajor ( ) const

Return the maximum number of major tick intervals.

Returns: Maximal number of major tick intervals

See also: setScaleMaxMajor(), scaleMaxMinor()

◆ scaleMaxMinor()

int QwtAbstractScale::scaleMaxMinor ( ) const

Return the maximum number of minor tick intervals.

Returns: Maximal number of minor tick intervals

See also: setScaleMaxMinor(), scaleMaxMajor()

◆ scaleStepSize()

double QwtAbstractScale::scaleStepSize ( ) const

Return the step size hint.

Returns: Hint for the step size of the scale

See also: setScaleStepSize(), QwtScaleEngine::divideScale()

◆ setAbstractScaleDraw()

void QwtAbstractScale::setAbstractScaleDraw ( QwtAbstractScaleDraw * scaleDraw )

protected

Set the scale draw object (English only)

Set the scale draw object.

scaleDraw must be created with new and will be deleted in the destructor or the next call of setAbstractScaleDraw().

See also: abstractScaleDraw()

◆ setLowerBound()

void QwtAbstractScale::setLowerBound ( double value )

Set the lower bound of the scale.

Parameters

value Lower bound value

See also: lowerBound(), setScale(), setUpperBound()

Note: For inverted scales, the lower bound is greater than the upper bound

◆ setScale() [1/3]

void QwtAbstractScale::setScale ( const QwtInterval & interval )

Specify a scale by interval.

Define a scale by an interval. The ticks are calculated using scaleMaxMinor(), scaleMaxMajor() and scaleStepSize().

Parameters

interval Interval object

◆ setScale() [2/3]

void QwtAbstractScale::setScale ( const QwtScaleDiv & scaleDiv )

Specify a scale by scale division.

When using this method, scaleMaxMinor(), scaleMaxMajor() and scaleStepSize() have no effect.

Parameters

scaleDiv Scale division object

See also: setAutoScale()

◆ setScale() [3/3]

void QwtAbstractScale::setScale	(	double	lowerBound,
		double	upperBound
	)

Specify a scale by interval bounds.

Define a scale by an interval. The ticks are calculated using scaleMaxMinor(), scaleMaxMajor() and scaleStepSize().

Parameters

lowerBound	Lower limit of the scale interval
upperBound	Upper limit of the scale interval

Note: For inverted scales, the lower bound is greater than the upper bound

◆ setScaleEngine()

void QwtAbstractScale::setScaleEngine ( QwtScaleEngine * scaleEngine )

Set the scale engine.

The scale engine is responsible for calculating the scale division and provides a transformation between scale and widget coordinates. scaleEngine must be created with new and will be deleted in the destructor or the next call of setScaleEngine().

Parameters

scaleEngine Scale engine object

◆ setScaleMaxMajor()

void QwtAbstractScale::setScaleMaxMajor ( int ticks )

Set the maximum number of major tick intervals.

The scale's major ticks are calculated automatically such that the number of major intervals does not exceed ticks. The default value is 5.

Parameters

ticks Maximal number of major ticks

See also: scaleMaxMajor(), setScaleMaxMinor(), setScaleStepSize(), QwtScaleEngine::divideInterval()

◆ setScaleMaxMinor()

void QwtAbstractScale::setScaleMaxMinor ( int ticks )

Set the maximum number of minor tick intervals.

The scale's minor ticks are calculated automatically such that the number of minor intervals does not exceed ticks. The default value is 3.

Parameters

ticks Maximal number of minor ticks

See also: scaleMaxMajor(), setScaleMaxMinor(), setScaleStepSize(), QwtScaleEngine::divideInterval()

◆ setScaleStepSize()

void QwtAbstractScale::setScaleStepSize ( double stepSize )

Set the step size used for calculating scale division.

The step size is a hint for calculating the intervals for the major ticks of the scale. A value of 0.0 is interpreted as no hint.

Parameters

stepSize Hint for the step size of the scale

See also: scaleStepSize(), QwtScaleEngine::divideScale()

Note: Position and distance between major ticks also depends on scaleMaxMajor()

◆ setUpperBound()

void QwtAbstractScale::setUpperBound ( double value )

Set the upper bound of the scale.

Parameters

value Upper bound value

See also: upperBound(), setScale(), setLowerBound()

Note: For inverted scales, the lower bound is greater than the upper bound

◆ transform()

int QwtAbstractScale::transform ( double value ) const

Transform a scale value to widget coordinates.

Parameters

value Scale value

Returns: Corresponding widget coordinate for value

See also: scaleMap(), invTransform()

◆ updateScaleDraw()

void QwtAbstractScale::updateScaleDraw ( )

protected

Update the scale draw (English only)

Recalculate ticks and scale boundaries.

Updates the scale draw by recalculating ticks and boundaries based on the current scale division.

◆ upperBound()

double QwtAbstractScale::upperBound ( ) const

Return the upper bound of the scale.

Returns: Upper bound value

See also: setUpperBound(), setScale(), lowerBound()

The documentation for this class was generated from the following files:

/home/runner/work/QWT/QWT/src/plot/qwt_abstract_scale.h
/home/runner/work/QWT/QWT/src/plot/qwt_abstract_scale.cpp

Classes

Public Member Functions

Protected Member Functions

Properties

Detailed Description

Constructor & Destructor Documentation

◆ QwtAbstractScale()

Member Function Documentation

◆ abstractScaleDraw() [1/2]

◆ abstractScaleDraw() [2/2]

◆ changeEvent()

◆ invTransform()

◆ isInverted()

◆ lowerBound()

◆ maximum()

◆ minimum()

◆ rescale()

◆ scaleChange()

◆ scaleDiv()

◆ scaleEngine() [1/2]

◆ scaleEngine() [2/2]

◆ scaleMap()

◆ scaleMaxMajor()

◆ scaleMaxMinor()

◆ scaleStepSize()

◆ setAbstractScaleDraw()

◆ setLowerBound()

◆ setScale() [1/3]

◆ setScale() [2/3]

◆ setScale() [3/3]

◆ setScaleEngine()

◆ setScaleMaxMajor()

◆ setScaleMaxMinor()

◆ setScaleStepSize()

◆ setUpperBound()

◆ transform()

◆ updateScaleDraw()

◆ upperBound()