QwtDial class provides a rounded range control. More...

#include <qwt_dial.h>

Inheritance diagram for QwtDial:

Classes
class	PrivateData

Public Types
enum	Shadow { Plain = QFrame::Plain , Raised = QFrame::Raised , Sunken = QFrame::Sunken }
	Frame shadow. More...

enum	Mode { RotateNeedle , RotateScale }
	Mode controlling whether the needle or the scale is rotating. More...

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

	~QwtDial () override
	Destructor.

void	setFrameShadow (Shadow)
	Set the frame shadow.

Shadow	frameShadow () const
	Return the frame shadow.

void	setLineWidth (int)
	Set the line width.

int	lineWidth () const
	Return the line width.

void	setMode (Mode)
	Set the mode.

Mode	mode () const
	Return the mode.

void	setScaleArc (double minArc, double maxArc)
	Set the scale arc range.

void	setMinScaleArc (double)
	Set the minimum scale arc.

double	minScaleArc () const
	Return the minimum scale arc.

void	setMaxScaleArc (double)
	Set the maximum scale arc.

double	maxScaleArc () const
	Return the maximum scale arc.

virtual void	setOrigin (double)
	Set the origin.

double	origin () const
	Return the origin.

void	setNeedle (QwtDialNeedle *)
	Set the needle.

const QwtDialNeedle *	needle () const
	Return the needle (const version)

QwtDialNeedle *	needle ()
	Return the needle.

QRect	boundingRect () const
	Return the bounding rectangle.

QRect	innerRect () const
	Return the inner rectangle.

virtual QRect	scaleInnerRect () const
	Return the scale inner rectangle.

virtual QSize	sizeHint () const override
	Return the size hint.

virtual QSize	minimumSizeHint () const override
	Return the minimum size hint.

void	setScaleDraw (QwtRoundScaleDraw *)
	Set the scale draw.

QwtRoundScaleDraw *	scaleDraw ()
	Return the scale draw.

const QwtRoundScaleDraw *	scaleDraw () const
	Return the scale draw (const version)

Public Member Functions inherited from QwtAbstractSlider
	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	wheelEvent (QWheelEvent *) override
	Wheel Event handler.

virtual void	paintEvent (QPaintEvent *) override
	Paint the dial.

virtual void	changeEvent (QEvent *) override
	Change Event handler.

virtual void	drawFrame (QPainter *)
	Draw the frame around the dial.

virtual void	drawContents (QPainter *) const
	Draw the contents inside the frame.

virtual void	drawFocusIndicator (QPainter *) const
	Draw the focus indicator.

void	invalidateCache ()
	Invalidate the internal caches used to speed up repainting.

virtual void	drawScale (QPainter *, const QPointF &center, double radius) const
	Draw the scale.

virtual void	drawScaleContents (QPainter *painter, const QPointF &center, double radius) const
	Draw the contents inside the scale.

virtual void	drawNeedle (QPainter *, const QPointF &, double radius, double direction, QPalette::ColorGroup) const
	Draw the needle.

virtual double	scrolledTo (const QPoint &) const override
	Determine the value for a new position of the slider handle.

virtual bool	isScrollPosition (const QPoint &) const override
	Determine what to do when the user presses a mouse button.

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

virtual void	scaleChange () override
	Invalidate the internal caches and call QwtAbstractSlider::scaleChange()

Protected Member Functions inherited from QwtAbstractSlider
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)

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

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

Protected Member Functions inherited from QwtAbstractScale
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
int	lineWidth

Shadow	frameShadow

Mode	mode

double	origin

double	minScaleArc

double	maxScaleArc

Properties inherited from QwtAbstractSlider
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

Additional Inherited Members
Public Slots inherited from QwtAbstractSlider
void	setValue (double value)
	Set the slider value (English only)

Signals inherited from QwtAbstractSlider
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.

Detailed Description

QwtDial class provides a rounded range control.

QwtDial is intended as base class for dial widgets like speedometers, compass widgets, clocks... A dial contains a scale and a needle indicating the current value of the dial. Depending on Mode one of them is fixed and the other is rotating. If not isReadOnly() the dial can be rotated by dragging the mouse or using keyboard inputs (see QwtAbstractSlider::keyPressEvent()). A dial might be wrapping, what means a rotation below/above one limit continues on the other limit (f.e compass). The scale might cover any arc of the dial, its values are related to the origin() of the dial. Often dials have to be updated very often according to values from external devices. For these high refresh rates QwtDial caches as much as possible. For derived classes it might be necessary to clear these caches manually according to attribute changes using invalidateCache().

See also: QwtCompass, QwtAnalogClock, QwtDialNeedle

Note: The controls and dials examples shows different types of dials.; QDial is more similar to QwtKnob than to QwtDial

Member Enumeration Documentation

◆ Mode

enum QwtDial::Mode

Mode controlling whether the needle or the scale is rotating.

Enumerator
RotateNeedle	The needle is rotating.
RotateScale	The needle is fixed, the scales are rotating.

◆ Shadow

enum QwtDial::Shadow

Frame shadow.

Unfortunately it is not possible to use QFrame::Shadow as a property of a widget that is not derived from QFrame. The following enum is made for the designer only. It is safe to use QFrame::Shadow instead.

Enumerator
Plain	QFrame::Plain.
Raised	QFrame::Raised.
Sunken	QFrame::Sunken.

Constructor & Destructor Documentation

◆ QwtDial()

QwtDial::QwtDial ( QWidget * parent = nullptr )

explicit

Constructor.

Create a dial widget with no needle. The scale is initialized to [ 0.0, 360.0 ] and 360 steps ( QwtAbstractSlider::setTotalSteps() ). The origin of the scale is at 90°, The value is set to 0.0. The default mode is QwtDial::RotateNeedle.

Parameters

parent Parent widget

Destructor

Member Function Documentation

◆ boundingRect()

QRect QwtDial::boundingRect ( ) const

Return the bounding rectangle.

Return bounding rectangle of the dial including the frame.

See also: setLineWidth(), scaleInnerRect(), innerRect()

◆ changeEvent()

void QwtDial::changeEvent ( QEvent * event )

overrideprotectedvirtual

Change Event handler.

Parameters

event Change event

Invalidates internal paint caches if necessary

Reimplemented from QwtAbstractScale.

◆ drawContents()

void QwtDial::drawContents ( QPainter * painter ) const

protectedvirtual

Draw the contents inside the frame.

QPalette::Window is the background color outside of the frame. QPalette::Base is the background color inside the frame. QPalette::WindowText is the background color inside the scale.

Parameters

painter Painter

See also: boundingRect(), innerRect(), scaleInnerRect(), QWidget::setPalette()

◆ drawFocusIndicator()

void QwtDial::drawFocusIndicator ( QPainter * painter ) const

protectedvirtual

Draw the focus indicator.

Parameters

painter Painter

◆ drawFrame()

void QwtDial::drawFrame ( QPainter * painter )

protectedvirtual

Draw the frame around the dial.

Parameters

painter Painter

See also: lineWidth(), frameShadow()

◆ drawNeedle()

void QwtDial::drawNeedle	(	QPainter *	painter,
		const QPointF &	center,
		double	radius,
		double	direction,
		QPalette::ColorGroup	colorGroup
	)		const

protectedvirtual

Draw the needle.

Parameters

painter	Painter
center	Center of the dial
radius	Length for the needle
direction	Direction of the needle in degrees, counter clockwise
colorGroup	ColorGroup

Reimplemented in QwtAnalogClock.

◆ drawScale()

void QwtDial::drawScale	(	QPainter *	painter,
		const QPointF &	center,
		double	radius
	)		const

protectedvirtual

Draw the scale.

Parameters

painter	Painter
center	Center of the dial
radius	Radius of the scale

◆ drawScaleContents()

void QwtDial::drawScaleContents	(	QPainter *	painter,
		const QPointF &	center,
		double	radius
	)		const

protectedvirtual

Draw the contents inside the scale.

Paints nothing.

Parameters

painter	Painter
center	Center of the contents circle
radius	Radius of the contents circle

Reimplemented in QwtCompass.

◆ frameShadow()

QwtDial::Shadow QwtDial::frameShadow ( ) const

Return the frame shadow.

Return frame shadow.

See also: setFrameShadow(), lineWidth(), QFrame::frameShadow()

◆ innerRect()

QRect QwtDial::innerRect ( ) const

Return the inner rectangle.

Return bounding rectangle of the circle inside the frame.

See also: setLineWidth(), scaleInnerRect(), boundingRect()

◆ isScrollPosition()

bool QwtDial::isScrollPosition ( const QPoint & pos ) const

overrideprotectedvirtual

Determine what to do when the user presses a mouse button.

Parameters

pos	Mouse position

Return values

True,when the inner circle contains pos

See also: scrolledTo()

Implements QwtAbstractSlider.

◆ lineWidth()

int QwtDial::lineWidth ( ) const

Return the line width.

Return line width of the frame.

See also: setLineWidth(), frameShadow(), lineWidth()

◆ maxScaleArc()

double QwtDial::maxScaleArc ( ) const

Return the maximum scale arc.

Return upper limit of the scale arc.

See also: setScaleArc()

◆ minimumSizeHint()

QSize QwtDial::minimumSizeHint ( ) const

overridevirtual

Return the minimum size hint.

Return minimum size hint.

See also: sizeHint()

◆ minScaleArc()

double QwtDial::minScaleArc ( ) const

Return the minimum scale arc.

Return lower limit of the scale arc.

See also: setScaleArc()

◆ mode()

QwtDial::Mode QwtDial::mode ( ) const

Return the mode.

Return mode of the dial.

See also: setMode(), origin(), setScaleArc(), value()

◆ needle() [1/2]

QwtDialNeedle * QwtDial::needle ( )

Return the needle.

Return needle.

See also: setNeedle()

◆ needle() [2/2]

const QwtDialNeedle * QwtDial::needle ( ) const

Return the needle (const version)

Return needle.

See also: setNeedle()

◆ origin()

double QwtDial::origin ( ) const

Return the origin.

The origin is the angle where scale and needle is relative to.

Returns: Origin of the dial

See also: setOrigin()

◆ paintEvent()

void QwtDial::paintEvent ( QPaintEvent * event )

overrideprotectedvirtual

Paint the dial.

Parameters

event Paint event

◆ scaleChange()

void QwtDial::scaleChange ( )

overrideprotectedvirtual

Invalidate the internal caches and call QwtAbstractSlider::scaleChange()

Reimplemented from QwtAbstractSlider.

◆ scaleDraw()

const QwtRoundScaleDraw * QwtDial::scaleDraw ( ) const

Return the scale draw (const version)

Return the scale draw.

◆ scaleInnerRect()

QRect QwtDial::scaleInnerRect ( ) const

virtual

Return the scale inner rectangle.

Return rectangle inside the scale.

See also: setLineWidth(), boundingRect(), innerRect()

◆ scrolledTo()

double QwtDial::scrolledTo ( const QPoint & pos ) const

overrideprotectedvirtual

Determine the value for a new position of the slider handle.

Parameters

pos	Mouse position

Returns: Value for the mouse position

See also: isScrollPosition()

Implements QwtAbstractSlider.

◆ setFrameShadow()

void QwtDial::setFrameShadow ( Shadow shadow )

Set the frame shadow.

Sets the frame shadow value from the frame style.

Parameters

shadow Frame shadow

See also: setLineWidth(), QFrame::setFrameShadow()

◆ setLineWidth()

void QwtDial::setLineWidth ( int lineWidth )

Set the line width.

Sets the line width of the frame.

Parameters

lineWidth Line width

See also: setFrameShadow()

◆ setMaxScaleArc()

void QwtDial::setMaxScaleArc ( double max )

Set the maximum scale arc.

Set the upper limit for the scale arc.

Parameters

max	Upper limit of the scale arc

See also: setScaleArc(), setMinScaleArc()

◆ setMinScaleArc()

void QwtDial::setMinScaleArc ( double min )

Set the minimum scale arc.

Set the lower limit for the scale arc.

Parameters

min	Lower limit of the scale arc

See also: setScaleArc(), setMaxScaleArc()

◆ setMode()

void QwtDial::setMode ( Mode mode )

Set the mode.

Change the mode of the dial.

In case of QwtDial::RotateNeedle the needle is rotating, in case of QwtDial::RotateScale, the needle points to origin() and the scale is rotating. The default mode is QwtDial::RotateNeedle.

Parameters

mode New mode

See also: mode(), setValue(), setOrigin()

◆ setNeedle()

void QwtDial::setNeedle ( QwtDialNeedle * needle )

Set the needle.

Set a needle for the dial.

Parameters

needle Needle

Warning: The needle will be deleted, when a different needle is set or in ~QwtDial()

◆ setOrigin()

void QwtDial::setOrigin ( double origin )

virtual

Set the origin.

Change the origin.

The origin is the angle where scale and needle is relative to.

Parameters

origin New origin

See also: origin()

◆ setScaleArc()

void QwtDial::setScaleArc	(	double	minArc,
		double	maxArc
	)

Set the scale arc range.

Change the arc of the scale.

Parameters

minArc	Lower limit
maxArc	Upper limit

See also: minScaleArc(), maxScaleArc()

◆ setScaleDraw()

void QwtDial::setScaleDraw ( QwtRoundScaleDraw * scaleDraw )

Set the scale draw.

Set an individual scale draw.

The motivation for setting a scale draw is often to overload QwtRoundScaleDraw::label() to return individual tick labels.

Parameters

scaleDraw Scale draw

Warning: The previous scale draw is deleted

◆ sizeHint()

QSize QwtDial::sizeHint ( ) const

overridevirtual

Return the size hint.

Return size hint.

See also: minimumSizeHint()

◆ sliderChange()

void QwtDial::sliderChange ( )

overrideprotectedvirtual

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 from QwtAbstractSlider.

◆ wheelEvent()

void QwtDial::wheelEvent ( QWheelEvent * event )

overrideprotectedvirtual

Wheel Event handler.

Parameters

event Wheel event

Reimplemented from QwtAbstractSlider.

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

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

Classes

Public Types

Public Member Functions

Protected Member Functions

Properties

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ Mode

◆ Shadow

Constructor & Destructor Documentation

◆ QwtDial()

Member Function Documentation

◆ boundingRect()

◆ changeEvent()

◆ drawContents()

◆ drawFocusIndicator()

◆ drawFrame()

◆ drawNeedle()

◆ drawScale()

◆ drawScaleContents()

◆ frameShadow()

◆ innerRect()

◆ isScrollPosition()

◆ lineWidth()

◆ maxScaleArc()

◆ minimumSizeHint()

◆ minScaleArc()

◆ mode()

◆ needle() [1/2]

◆ needle() [2/2]

◆ origin()

◆ paintEvent()

◆ scaleChange()

◆ scaleDraw()

◆ scaleInnerRect()

◆ scrolledTo()

◆ setFrameShadow()

◆ setLineWidth()

◆ setMaxScaleArc()

◆ setMinScaleArc()

◆ setMode()

◆ setNeedle()

◆ setOrigin()

◆ setScaleArc()

◆ setScaleDraw()

◆ sizeHint()

◆ sliderChange()

◆ wheelEvent()