An abstract base class for slider widgets with a scale. More...

#include <qwt_abstract_slider.h>

Inheritance diagram for QwtAbstractSlider:

Classes
class	PrivateData

Public Slots
void	setValue (double value)
	Set the slider value (English only)

Signals
void	valueChanged (double value)
	Notify a change of value.

void	sliderPressed ()
	Signal emitted when the user presses the movable part of the slider.

void	sliderReleased ()
	Signal emitted when the user releases the movable part of the slider.

void	sliderMoved (double value)
	Signal emitted when the user moves the slider with the mouse.

Public Member Functions
	QwtAbstractSlider (QWidget *parent=nullptr)
	Constructor for QwtAbstractSlider (English only)

	~QwtAbstractSlider () override
	Destructor for QwtAbstractSlider (English only)

void	setValid (bool)
	Set whether the slider is valid (English only)

bool	isValid () const
	Return whether the slider is valid (English only)

double	value () const
	Return the current value (English only)

void	setWrapping (bool)
	Set whether wrapping is enabled (English only)

bool	wrapping () const
	Return whether wrapping is enabled (English only)

void	setTotalSteps (uint)
	Set the total number of steps (English only)

uint	totalSteps () const
	Return the total number of steps (English only)

void	setSingleSteps (uint)
	Set the number of single steps (English only)

uint	singleSteps () const
	Return the number of single steps (English only)

void	setPageSteps (uint)
	Set the number of page steps (English only)

uint	pageSteps () const
	Return the number of page steps (English only)

void	setStepAlignment (bool)
	Set whether step alignment is enabled (English only)

bool	stepAlignment () const
	Return whether step alignment is enabled (English only)

void	setTracking (bool)
	Set whether tracking is enabled (English only)

bool	isTracking () const
	Return whether tracking is enabled (English only)

void	setReadOnly (bool)
	Set whether the slider is read-only (English only)

bool	isReadOnly () const
	Return whether the slider is read-only (English only)

void	setInvertedControls (bool)
	Set whether controls are inverted (English only)

bool	invertedControls () const
	Return whether controls are inverted (English only)

Public Member Functions inherited from QwtAbstractScale
	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	mousePressEvent (QMouseEvent *) override
	Handle mouse press events (English only)

virtual void	mouseReleaseEvent (QMouseEvent *) override
	Handle mouse release events (English only)

virtual void	mouseMoveEvent (QMouseEvent *) override
	Handle mouse move events (English only)

virtual void	keyPressEvent (QKeyEvent *) override
	Handle key press events (English only)

virtual void	wheelEvent (QWheelEvent *) override
	Handle wheel events (English only)

virtual bool	isScrollPosition (const QPoint &pos) const =0

virtual double	scrolledTo (const QPoint &pos) const =0

void	incrementValue (int stepCount)
	Increment the value by a number of steps (English only)

virtual void	scaleChange () override
	Handle scale changes (English only)

virtual void	sliderChange ()
	Handle slider changes (English only)

double	incrementedValue (double value, int stepCount) const
	Calculate incremented value (English only)

Protected Member Functions inherited from QwtAbstractScale
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)

Properties
double	value

uint	totalSteps

uint	singleSteps

uint	pageSteps

bool	stepAlignment

bool	readOnly

bool	tracking

bool	wrapping

bool	invertedControls

Properties inherited from QwtAbstractScale
double	lowerBound

double	upperBound

int	scaleMaxMajor

int	scaleMaxMinor

double	scaleStepSize

Detailed Description

An abstract base class for slider widgets with a scale.

A slider widget displays a value according to a scale. The class is designed as a common super class for widgets like QwtKnob, QwtDial and QwtSlider. When the slider is not readOnly(), its value can be modified by keyboard, mouse and wheel inputs. The range of the slider is divided into a number of steps from which the value increments according to user inputs depend. Only for linear scales the number of steps correspond with a fixed step size.

Constructor & Destructor Documentation

◆ QwtAbstractSlider()

QwtAbstractSlider::QwtAbstractSlider ( QWidget * parent = nullptr )

explicit

Constructor for QwtAbstractSlider (English only)

Constructor for QwtAbstractSlider.

The scale is initialized to [0.0, 100.0], the number of steps is set to 100 with 1 and 10 as single and page step sizes. Step alignment is enabled. The initial value is invalid.

Parameters

parent Parent widget

Destructor for QwtAbstractSlider

Member Function Documentation

◆ incrementedValue()

double QwtAbstractSlider::incrementedValue	(	double	value,
		int	stepCount
	)		const

protected

Calculate incremented value (English only)

Increment a value.

Parameters

value	Value to increment
stepCount	Number of steps

Returns: Incremented value

See also: incrementValue(), setTotalSteps()

◆ incrementValue()

void QwtAbstractSlider::incrementValue ( int stepCount )

protected

Increment the value by a number of steps (English only)

Increment the slider.

The step size depends on the number of totalSteps()

Parameters

stepCount Number of steps

See also: setTotalSteps(), incrementedValue()

◆ invertedControls()

bool QwtAbstractSlider::invertedControls ( ) const

Return whether controls are inverted (English only)

Check if controls are inverted.

Returns: True, when the controls are inverted

See also: setInvertedControls()

◆ isReadOnly()

bool QwtAbstractSlider::isReadOnly ( ) const

Return whether the slider is read-only (English only)

Check if read-only mode is enabled.

Returns: True if read-only mode is enabled

See also: setReadOnly()

◆ isScrollPosition()

virtual bool QwtAbstractSlider::isScrollPosition ( const QPoint & pos ) const

protectedpure virtual

Implemented in QwtDial, QwtKnob, and QwtSlider.

◆ isTracking()

bool QwtAbstractSlider::isTracking ( ) const

Return whether tracking is enabled (English only)

Check if tracking is enabled.

Returns: True if tracking is enabled

See also: setTracking()

◆ isValid()

bool QwtAbstractSlider::isValid ( ) const

Return whether the slider is valid (English only)

Check if the value is valid.

Returns: True if the value is invalid

◆ keyPressEvent()

void QwtAbstractSlider::keyPressEvent ( QKeyEvent * event )

overrideprotectedvirtual

Handle key press events (English only)

Handle key press events.

QwtAbstractSlider handles the following keys:

Qt::Key_Left: Add/Subtract singleSteps() in direction to lowerBound()
Qt::Key_Right: Add/Subtract singleSteps() in direction to upperBound()
Qt::Key_Down: Subtract singleSteps(), when invertedControls() is false
Qt::Key_Up: Add singleSteps(), when invertedControls() is false
Qt::Key_PageDown: Subtract pageSteps(), when invertedControls() is false
Qt::Key_PageUp: Add pageSteps(), when invertedControls() is false
Qt::Key_Home: Set the value to the minimum()
Qt::Key_End: Set the value to the maximum()
Parameters

event Key event

See also
isReadOnly(), wheelEvent()

Reimplemented in QwtCompass.

◆ mouseMoveEvent()

void QwtAbstractSlider::mouseMoveEvent ( QMouseEvent * event )

overrideprotectedvirtual

Handle mouse move events (English only)

Handle mouse move events.

Parameters

event Mouse event

Updates the slider value while scrolling.

See also: mousePressEvent(), mouseReleaseEvent()

◆ mousePressEvent()

void QwtAbstractSlider::mousePressEvent ( QMouseEvent * event )

overrideprotectedvirtual

Handle mouse press events (English only)

Handle mouse press events.

Parameters

event Mouse event

Initiates scrolling if the position is valid.

See also: mouseMoveEvent(), mouseReleaseEvent()

Reimplemented in QwtSlider.

◆ mouseReleaseEvent()

void QwtAbstractSlider::mouseReleaseEvent ( QMouseEvent * event )

overrideprotectedvirtual

Handle mouse release events (English only)

Handle mouse release events.

Parameters

event Mouse event

Ends scrolling and emits valueChanged() if needed.

See also: mousePressEvent(), mouseMoveEvent()

Reimplemented in QwtSlider.

◆ pageSteps()

uint QwtAbstractSlider::pageSteps ( ) const

Return the number of page steps (English only)

Return the number of page steps.

Returns: Number of steps

See also: setPageSteps(), totalSteps(), singleSteps()

◆ scaleChange()

void QwtAbstractSlider::scaleChange ( )

overrideprotectedvirtual

Handle scale changes (English only)

Update the slider according to modifications of the scale.

Updates the current value to stay within the new scale range and emits valueChanged() if the value was adjusted.

See also: sliderChange(), valueChanged()

Reimplemented from QwtAbstractScale.

Reimplemented in QwtDial, and QwtSlider.

◆ scrolledTo()

virtual double QwtAbstractSlider::scrolledTo ( const QPoint & pos ) const

protectedpure virtual

Implemented in QwtDial, QwtKnob, and QwtSlider.

◆ setInvertedControls()

void QwtAbstractSlider::setInvertedControls ( bool on )

Set whether controls are inverted (English only)

Invert wheel and key events.

Usually scrolling the mouse wheel "up" and using keys like page up will increase the slider's value towards its maximum. When invertedControls() is enabled the value is scrolled towards its minimum. Inverting the controls might be f.e. useful for a vertical slider with an inverted scale (decreasing from top to bottom).

Parameters

on	Invert controls when true

See also: invertedControls(), keyEvent(), wheelEvent()

◆ setPageSteps()

void QwtAbstractSlider::setPageSteps ( uint stepCount )

Set the number of page steps (English only)

Set the number of page steps.

The range of the slider is divided into a number of steps from which the value increments according to user inputs depend.

Parameters

[in] stepCount Number of steps

See also: pageSteps(), setTotalSteps(), setSingleSteps()

◆ setReadOnly()

void QwtAbstractSlider::setReadOnly ( bool on )

Set whether the slider is read-only (English only)

Enable or disable read-only mode.

In read-only mode the slider can't be controlled by mouse or keyboard.

Parameters

on	Enables read-only mode if true

See also: isReadOnly()

Warning: The focus policy is set to Qt::StrongFocus or Qt::NoFocus

◆ setSingleSteps()

void QwtAbstractSlider::setSingleSteps ( uint stepCount )

Set the number of single steps (English only)

Set the number of steps for a single increment.

The range of the slider is divided into a number of steps from which the value increments according to user inputs depend.

Parameters

[in] stepCount Number of steps

See also: singleSteps(), setTotalSteps(), setPageSteps()

◆ setStepAlignment()

void QwtAbstractSlider::setStepAlignment ( bool on )

Set whether step alignment is enabled (English only)

Enable step alignment.

When step alignment is enabled values resulting from slider movements are aligned to the step size.

Parameters

on	Enable step alignment when true

See also: stepAlignment()

◆ setTotalSteps()

void QwtAbstractSlider::setTotalSteps ( uint stepCount )

Set the total number of steps (English only)

Set the number of steps.

The range of the slider is divided into a number of steps from which the value increments according to user inputs depend. The default setting is 100.

Parameters

[in] stepCount Number of steps

See also: totalSteps(), setSingleSteps(), setPageSteps()

◆ setTracking()

void QwtAbstractSlider::setTracking ( bool on )

Set whether tracking is enabled (English only)

Enable or disable tracking.

If tracking is enabled, the slider emits the valueChanged() signal while the movable part of the slider is being dragged. If tracking is disabled, the slider emits the valueChanged() signal only when the user releases the slider. Tracking is enabled by default.

Parameters

on	True to enable tracking, false to disable

See also: isTracking(), sliderMoved()

◆ setValid()

void QwtAbstractSlider::setValid ( bool on )

Set whether the slider is valid (English only)

Set the value to be valid or invalid.

Parameters

on	When true, the value is invalidated

See also: setValue()

◆ setValue

void QwtAbstractSlider::setValue ( double value )

slot

Set the slider value (English only)

Set the slider to the specified value.

Parameters

value New value

See also: setValid(), sliderChange(), valueChanged()

◆ setWrapping()

void QwtAbstractSlider::setWrapping ( bool on )

Set whether wrapping is enabled (English only)

Enable or disable wrapping.

If wrapping is true stepping up from upperBound() value will take you to the minimum() value and vice versa.

Parameters

on	Enable wrapping when true

See also: wrapping()

◆ singleSteps()

uint QwtAbstractSlider::singleSteps ( ) const

Return the number of single steps (English only)

Return the number of single steps.

Returns: Number of steps

See also: setSingleSteps(), totalSteps(), pageSteps()

◆ sliderChange()

void QwtAbstractSlider::sliderChange ( )

protectedvirtual

Handle slider changes (English only)

Handle slider changes.

Called when the slider needs to update its appearance. The default implementation calls update().

See also: setValue(), incrementValue()

Reimplemented in QwtDial.

◆ sliderMoved

void QwtAbstractSlider::sliderMoved ( double value )

signal

Signal emitted when the user moves the slider with the mouse.

Parameters

value New value

See also: valueChanged()

◆ stepAlignment()

bool QwtAbstractSlider::stepAlignment ( ) const

Return whether step alignment is enabled (English only)

Check if step alignment is enabled.

Returns: True, when step alignment is enabled

See also: setStepAlignment()

◆ totalSteps()

uint QwtAbstractSlider::totalSteps ( ) const

Return the total number of steps (English only)

Return the number of steps.

Returns: Number of steps

See also: setTotalSteps(), singleSteps(), pageSteps()

◆ value()

double QwtAbstractSlider::value ( ) const

Return the current value (English only)

Return the current value.

Returns: Current slider value

See also: setValue()

◆ valueChanged

void QwtAbstractSlider::valueChanged ( double value )

signal

Notify a change of value.

When tracking is enabled (default setting), this signal will be emitted every time the value changes.

Parameters

value New value

See also: setTracking(), sliderMoved()

◆ wheelEvent()

void QwtAbstractSlider::wheelEvent ( QWheelEvent * event )

overrideprotectedvirtual

Handle wheel events (English only)

Handle wheel events.

In/decreases the value by a number of steps. The direction depends on the invertedControls() property. When the control or shift modifier is pressed the wheel delta (divided by 120) is mapped to an increment according to pageSteps(). Otherwise it is mapped to singleSteps().

Parameters

event Wheel event

See also: keyPressEvent()

Reimplemented in QwtDial.

◆ wrapping()

bool QwtAbstractSlider::wrapping ( ) const

Return whether wrapping is enabled (English only)

Check if wrapping is enabled.

Returns: True, when wrapping is set

See also: setWrapping()

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

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

Classes

Public Slots

Signals

Public Member Functions

Protected Member Functions

Properties

Detailed Description

Constructor & Destructor Documentation

◆ QwtAbstractSlider()

Member Function Documentation

◆ incrementedValue()

◆ incrementValue()

◆ invertedControls()

◆ isReadOnly()

◆ isScrollPosition()

◆ isTracking()

◆ isValid()

◆ keyPressEvent()

◆ mouseMoveEvent()

◆ mousePressEvent()

◆ mouseReleaseEvent()

◆ pageSteps()

◆ scaleChange()

◆ scrolledTo()

◆ setInvertedControls()

◆ setPageSteps()

◆ setReadOnly()

◆ setSingleSteps()

◆ setStepAlignment()

◆ setTotalSteps()

◆ setTracking()

◆ setValid()

◆ setValue

◆ setWrapping()

◆ singleSteps()

◆ sliderChange()

◆ sliderMoved

◆ stepAlignment()

◆ totalSteps()

◆ value()

◆ valueChanged

◆ wheelEvent()

◆ wrapping()