The Knob Widget. More...

#include <qwt_knob.h>

Inheritance diagram for QwtKnob:

Classes
class	PrivateData

Public Types
enum	KnobStyle { Flat, Raised, Sunken, Styled }
	Style of the knob surface. More...

enum	MarkerStyle { NoMarker = -1, Tick, Triangle, Dot, Nub, Notch }
	Marker type. More...

Public Member Functions
Qt::Alignment	alignment () const

int	borderWidth () const

QRect	knobRect () const

KnobStyle	knobStyle () const

int	knobWidth () const

int	markerSize () const

MarkerStyle	markerStyle () const

virtual QSize	minimumSizeHint () const

int	numTurns () const

	QwtKnob (QWidget *parent=NULL)
	Constructor. More...

const QwtRoundScaleDraw *	scaleDraw () const

QwtRoundScaleDraw *	scaleDraw ()

void	setAlignment (Qt::Alignment)
	Set the alignment of the knob. More...

void	setBorderWidth (int bw)
	Set the knob's border width. More...

void	setKnobStyle (KnobStyle)
	Set the knob type. More...

void	setKnobWidth (int)
	Change the knob's width. More...

void	setMarkerSize (int)
	Set the size of the marker. More...

void	setMarkerStyle (MarkerStyle)
	Set the marker type of the knob. More...

void	setNumTurns (int)
	Set the number of turns. More...

void	setScaleDraw (QwtRoundScaleDraw *)

void	setTotalAngle (double angle)
	Set the total angle by which the knob can be turned. More...

virtual QSize	sizeHint () const

double	totalAngle () const

virtual	~QwtKnob ()
	Destructor. More...

Public Member Functions inherited from QwtAbstractSlider
bool	invertedControls () const

bool	isReadOnly () const

bool	isTracking () const

bool	isValid () const

uint	pageSteps () const

	QwtAbstractSlider (QWidget *parent=NULL)
	Constructor. More...

void	setInvertedControls (bool)

void	setPageSteps (uint)
	Set the number of steps for a page increment. More...

void	setReadOnly (bool)

void	setSingleSteps (uint)
	Set the number of steps for a single increment. More...

void	setStepAlignment (bool)
	Enable step alignment. More...

void	setTotalSteps (uint)
	Set the number of steps. More...

void	setTracking (bool)
	Enables or disables tracking. More...

void	setValid (bool)

void	setWrapping (bool)

uint	singleSteps () const

bool	stepAlignment () const

uint	totalSteps () const

double	value () const

bool	wrapping () const

virtual	~QwtAbstractSlider ()
	Destructor. More...

Public Member Functions inherited from QwtAbstractScale
double	invTransform (int) const

bool	isInverted () const

double	lowerBound () const

double	maximum () const

double	minimum () const

	QwtAbstractScale (QWidget *parent=NULL)

const QwtScaleDiv &	scaleDiv () const

const QwtScaleEngine *	scaleEngine () const

QwtScaleEngine *	scaleEngine ()

const QwtScaleMap &	scaleMap () const

int	scaleMaxMajor () const

int	scaleMaxMinor () const

double	scaleStepSize () const

void	setLowerBound (double value)

void	setScale (double lowerBound, double upperBound)
	Specify a scale. More...

void	setScale (const QwtInterval &)
	Specify a scale. More...

void	setScale (const QwtScaleDiv &)
	Specify a scale. More...

void	setScaleEngine (QwtScaleEngine *)
	Set a scale engine. More...

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

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

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

void	setUpperBound (double value)

int	transform (double) const

double	upperBound () const

virtual	~QwtAbstractScale ()
	Destructor. More...

Protected Member Functions
virtual void	changeEvent (QEvent *)

virtual void	drawFocusIndicator (QPainter *) const

virtual void	drawKnob (QPainter *, const QRectF &) const
	Draw the knob. More...

virtual void	drawMarker (QPainter *, const QRectF &, double arc) const
	Draw the marker at the knob's front. More...

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

virtual void	paintEvent (QPaintEvent *)

virtual double	scrolledTo (const QPoint &) const
	Determine the value for a new position of the mouse. More...

Protected Member Functions inherited from QwtAbstractSlider
double	incrementedValue (double value, int stepCount) const

void	incrementValue (int numSteps)

virtual void	keyPressEvent (QKeyEvent *)

virtual void	mouseMoveEvent (QMouseEvent *)

virtual void	mousePressEvent (QMouseEvent *)

virtual void	mouseReleaseEvent (QMouseEvent *)

virtual void	scaleChange ()

virtual void	sliderChange ()
	Calling update() More...

virtual void	wheelEvent (QWheelEvent *)

Protected Member Functions inherited from QwtAbstractScale
const QwtAbstractScaleDraw *	abstractScaleDraw () const

QwtAbstractScaleDraw *	abstractScaleDraw ()

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

void	setAbstractScaleDraw (QwtAbstractScaleDraw *)
	Set a scale draw. More...

void	updateScaleDraw ()

Properties
Qt::Alignment	alignment

int	borderWidth
	Return the border width. More...

KnobStyle	knobStyle

int	knobWidth
	Return the width of the knob. More...

int	markerSize

MarkerStyle	markerStyle

int	numTurns

double	totalAngle

Properties inherited from QwtAbstractSlider
bool	invertedControls

uint	pageSteps

bool	readOnly

uint	singleSteps

bool	stepAlignment

uint	totalSteps

bool	tracking

double	value
	Returns the current value. More...

bool	wrapping

Properties inherited from QwtAbstractScale
double	lowerBound

int	scaleMaxMajor

int	scaleMaxMinor

double	scaleStepSize

double	upperBound

Private Attributes
PrivateData *	d_data

Additional Inherited Members
Public Slots inherited from QwtAbstractSlider
void	setValue (double val)

Signals inherited from QwtAbstractSlider
void	sliderMoved (double value)

void	sliderPressed ()

void	sliderReleased ()

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

Detailed Description

The Knob Widget.

The QwtKnob widget imitates look and behavior of a volume knob on a radio. It looks similar to QDial - not to QwtDial.

The value range of a knob might be divided into several turns.

The layout of the knob depends on the knobWidth().

width > 0 The diameter of the knob is fixed and the knob is aligned according to the alignment() flags inside of the contentsRect().
width <= 0 The knob is extended to the minimum of width/height of the contentsRect() and aligned in the other direction according to alignment().

Setting a fixed knobWidth() is helpful to align several knobs with different scale labels.

Definition at line 42 of file qwt_knob.h.

Member Enumeration Documentation

enum QwtKnob::KnobStyle

Style of the knob surface.

Depending on the KnobStyle the surface of the knob is filled from the brushes of the widget palette().

See also: setKnobStyle(), knobStyle()

Enumerator
Flat	Fill the knob with a brush from QPalette::Button.
Raised	Build a gradient from QPalette::Midlight and QPalette::Button.
Sunken	Build a gradient from QPalette::Midlight, QPalette::Button and QPalette::Midlight
Styled	Build a radial gradient from QPalette::Button like it is used for QDial in various Qt styles.

Definition at line 66 of file qwt_knob.h.

enum QwtKnob::MarkerStyle

Marker type.

The marker indicates the current value on the knob The default setting is a Notch marker.

See also: setMarkerStyle(), setMarkerSize()

Enumerator
NoMarker	Don't paint any marker.
Tick	Paint a single tick in QPalette::ButtonText color.
Triangle	Paint a triangle in QPalette::ButtonText color.
Dot	Paint a circle in QPalette::ButtonText color.
Nub	Draw a raised ellipse with a gradient build from QPalette::Light and QPalette::Mid
Notch	Draw a sunken ellipse with a gradient build from QPalette::Light and QPalette::Mid

Definition at line 95 of file qwt_knob.h.

Constructor & Destructor Documentation

QwtKnob::QwtKnob ( QWidget * parent = NULL )

explicit

Constructor.

Construct a knob with an angle of 270°. The style is QwtKnob::Raised and the marker style is QwtKnob::Notch. The width of the knob is set to 50 pixels.

Parameters

parent Parent widget

See also: setTotalAngle()

Definition at line 110 of file qwt_knob.cpp.

QwtKnob::~QwtKnob ( )

virtual

Destructor.

Definition at line 127 of file qwt_knob.cpp.

Member Function Documentation

Qt::Alignment QwtKnob::alignment ( ) const

int QwtKnob::borderWidth ( ) const

void QwtKnob::changeEvent ( QEvent * event )

protectedvirtual

Handle QEvent::StyleChange and QEvent::FontChange;

Parameters

event Change event

Reimplemented from QwtAbstractScale.

Definition at line 438 of file qwt_knob.cpp.

void QwtKnob::drawFocusIndicator ( QPainter * painter ) const

protectedvirtual

Draw the focus indicator

Parameters

painter Painter

Definition at line 706 of file qwt_knob.cpp.

void QwtKnob::drawKnob	(	QPainter *	painter,
		const QRectF &	knobRect
	)		const

protectedvirtual

Draw the knob.

Parameters

painter	painter
knobRect	Bounding rectangle of the knob (without scale)

Definition at line 496 of file qwt_knob.cpp.

void QwtKnob::drawMarker	(	QPainter *	painter,
		const QRectF &	rect,
		double	angle
	)		const

protectedvirtual

Draw the marker at the knob's front.

Parameters

painter	Painter
rect	Bounding rectangle of the knob without scale
angle	Angle of the marker in degrees ( clockwise, 0 at the 12 o'clock position )

Definition at line 583 of file qwt_knob.cpp.

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

protectedvirtual

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

Parameters

pos	Mouse position

Return values

True,when pos is inside the circle of the knob.

See also: scrolledTo()

Implements QwtAbstractSlider.

Definition at line 354 of file qwt_knob.cpp.

QRect QwtKnob::knobRect ( ) const

Calculate the bounding rectangle of the knob without the scale

Returns: Bounding rectangle of the knob

See also: knobWidth(), alignment(), QWidget::contentsRect()

Definition at line 299 of file qwt_knob.cpp.

KnobStyle QwtKnob::knobStyle ( ) const

int QwtKnob::knobWidth ( ) const

int QwtKnob::markerSize ( ) const

MarkerStyle QwtKnob::markerStyle ( ) const

QSize QwtKnob::minimumSizeHint ( ) const

virtual

Returns: Minimum size hint

See also: sizeHint()

Definition at line 852 of file qwt_knob.cpp.

int QwtKnob::numTurns ( ) const

void QwtKnob::paintEvent ( QPaintEvent * event )

protectedvirtual

Repaint the knob

Parameters

event Paint event

Definition at line 458 of file qwt_knob.cpp.

const QwtRoundScaleDraw * QwtKnob::scaleDraw ( ) const

Returns: the scale draw of the knob

See also: setScaleDraw()

Definition at line 279 of file qwt_knob.cpp.

QwtRoundScaleDraw * QwtKnob::scaleDraw ( )

Returns: the scale draw of the knob

See also: setScaleDraw()

Definition at line 288 of file qwt_knob.cpp.

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

protectedvirtual

Determine the value for a new position of the mouse.

Parameters

pos	Mouse position

Returns: Value for the mouse position

See also: isScrollPosition()

Implements QwtAbstractSlider.

Definition at line 380 of file qwt_knob.cpp.

void QwtKnob::setAlignment ( Qt::Alignment alignment )

Set the alignment of the knob.

Similar to a QLabel::alignment() the flags decide how to align the knob inside of contentsRect().

The default setting is Qt::AlignCenter

Parameters

alignment Or'd alignment flags

See also: alignment(), setKnobWidth(), knobRect()

Definition at line 739 of file qwt_knob.cpp.

void QwtKnob::setBorderWidth ( int borderWidth )

Set the knob's border width.

Parameters

borderWidth new border width

Definition at line 799 of file qwt_knob.cpp.

void QwtKnob::setKnobStyle ( KnobStyle knobStyle )

Set the knob type.

Parameters

knobStyle Knob type

See also: knobStyle(), setBorderWidth()

Definition at line 138 of file qwt_knob.cpp.

void QwtKnob::setKnobWidth ( int width )

Change the knob's width.

Setting a fixed value for the diameter of the knob is helpful for aligning several knobs in a row.

Parameters

width New width

See also: knobWidth(), setAlignment()

Note: Modifies the sizePolicy()

Definition at line 768 of file qwt_knob.cpp.

void QwtKnob::setMarkerSize ( int size )

Set the size of the marker.

When setting a size <= 0 the marker will automatically scaled to 40% of the radius of the knob.

See also: markerSize(), markerStyle()

Definition at line 821 of file qwt_knob.cpp.

void QwtKnob::setMarkerStyle ( MarkerStyle markerStyle )

Set the marker type of the knob.

Parameters

markerStyle Marker type

See also: markerStyle(), setMarkerSize()

Definition at line 162 of file qwt_knob.cpp.

void QwtKnob::setNumTurns ( int numTurns )

Set the number of turns.

When numTurns > 1 the knob can be turned several times around its axis

otherwise the total angle is floored to 360°.

See also: numTurns(), totalAngle(), setTotalAngle()

Definition at line 226 of file qwt_knob.cpp.

void QwtKnob::setScaleDraw ( QwtRoundScaleDraw * scaleDraw )

Change the scale draw of the knob

For changing the labels of the scales, it is necessary to derive from QwtRoundScaleDraw and overload QwtRoundScaleDraw::label().

See also: scaleDraw()

Definition at line 266 of file qwt_knob.cpp.

void QwtKnob::setTotalAngle ( double angle )

Set the total angle by which the knob can be turned.

Parameters

angle Angle in degrees.

The angle has to be between [10, 360] degrees. Angles above 360 ( so that the knob can be turned several times around its axis ) have to be set using setNumTurns().

The default angle is 270 degrees.

See also: totalAngle(), setNumTurns()

Definition at line 192 of file qwt_knob.cpp.

QSize QwtKnob::sizeHint ( ) const

virtual

Returns: sizeHint()

Definition at line 842 of file qwt_knob.cpp.

double QwtKnob::totalAngle ( ) const

Member Data Documentation

PrivateData* QwtKnob::d_data

private

Definition at line 174 of file qwt_knob.h.

Property Documentation

Qt::Alignment QwtKnob::alignment

readwrite

Returns: Alignment of the knob inside of contentsRect()

See also: setAlignment(), knobWidth(), knobRect()

Definition at line 50 of file qwt_knob.h.

int QwtKnob::borderWidth

readwrite

Return the border width.

Definition at line 55 of file qwt_knob.h.

QwtKnob::KnobStyle QwtKnob::knobStyle

readwrite

Returns: Marker type of the knob

See also: setKnobStyle(), setBorderWidth()

Definition at line 48 of file qwt_knob.h.

int QwtKnob::knobWidth

readwrite

Return the width of the knob.

Definition at line 49 of file qwt_knob.h.

int QwtKnob::markerSize

readwrite

Returns: Marker size

See also: setMarkerSize()

Definition at line 54 of file qwt_knob.h.

QwtKnob::MarkerStyle QwtKnob::markerStyle

readwrite

Returns: Marker type of the knob

See also: setMarkerStyle(), setMarkerSize()

Definition at line 53 of file qwt_knob.h.

int QwtKnob::numTurns

readwrite

Returns: Number of turns.

When the total angle is below 360° numTurns() is ceiled to 1.

See also: setNumTurns(), setTotalAngle(), totalAngle()

Definition at line 52 of file qwt_knob.h.

double QwtKnob::totalAngle

readwrite

Returns: the total angle

See also: setTotalAngle(), setNumTurns(), numTurns()

Definition at line 51 of file qwt_knob.h.

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

Classes

Public Types

Public Member Functions

Protected Member Functions

Properties

Private Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

Property Documentation