The Wheel Widget. More...

#include <qwt_wheel.h>

Inheritance diagram for QwtWheel:

Public Slots
void	setValue (double)
	Set a new value without adjusting to the step raster. More...

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

void	setViewAngle (double)
	Specify the visible portion of the wheel. More...

void	setMass (double)
	Set the slider's mass for flywheel effect. More...

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

void	wheelPressed ()

void	wheelReleased ()

void	wheelMoved (double value)

Public Member Functions
	QwtWheel (QWidget *parent=NULL)
	Constructor.

virtual	~QwtWheel ()
	Destructor.

double	value () const

void	setOrientation (Qt::Orientation)
	Set the wheel's orientation. More...

Qt::Orientation	orientation () const

double	totalAngle () const

double	viewAngle () const

void	setTickCount (int)
	Adjust the number of grooves in the wheel's surface. More...

int	tickCount () const

void	setWheelWidth (int)
	Set the width of the wheel. More...

int	wheelWidth () const

void	setWheelBorderWidth (int)
	Set the wheel border width of the wheel. More...

int	wheelBorderWidth () const

void	setBorderWidth (int)
	Set the border width. More...

int	borderWidth () const

void	setInverted (bool)
	En/Disable inverted appearance. More...

bool	isInverted () const

void	setWrapping (bool)
	En/Disable wrapping. More...

bool	wrapping () const

void	setSingleStep (double)
	Set the step size of the counter. More...

double	singleStep () const

void	setPageStepCount (int)
	Set the page step count. More...

int	pageStepCount () const

void	setStepAlignment (bool on)
	En/Disable step alignment. More...

bool	stepAlignment () const

void	setRange (double min, double max)
	Set the minimum and maximum values. More...

void	setMinimum (double)

double	minimum () const

void	setMaximum (double)

double	maximum () const

void	setUpdateInterval (int)
	Specify the update interval when the wheel is flying. More...

int	updateInterval () const

void	setTracking (bool)
	En/Disable tracking. More...

bool	isTracking () const

double	mass () const

Protected Member Functions
virtual void	paintEvent (QPaintEvent *)
	Qt Paint Event. More...

virtual void	mousePressEvent (QMouseEvent *)
	Mouse press event handler. More...

virtual void	mouseReleaseEvent (QMouseEvent *)
	Mouse Release Event handler. More...

virtual void	mouseMoveEvent (QMouseEvent *)
	Mouse Move Event handler. More...

virtual void	keyPressEvent (QKeyEvent *)

virtual void	wheelEvent (QWheelEvent *)
	Handle wheel events. More...

virtual void	timerEvent (QTimerEvent *)
	Qt timer event. More...

void	stopFlying ()
	Stop the flying movement of the wheel.

QRect	wheelRect () const

virtual QSize	sizeHint () const

virtual QSize	minimumSizeHint () const

virtual void	drawTicks (QPainter *, const QRectF &)

virtual void	drawWheelBackground (QPainter *, const QRectF &)

virtual double	valueAt (const QPoint &) const

Detailed Description

The Wheel Widget.

The wheel widget can be used to change values over a very large range in very small steps. Using the setMass() member, it can be configured as a flying wheel.

The default range of the wheel is [0.0, 100.0]

See also: The radio example.

Member Function Documentation

◆ borderWidth()

int QwtWheel::borderWidth ( ) const

Returns: Border width

See also: setBorderWidth()

◆ drawTicks()

void QwtWheel::drawTicks	(	QPainter *	painter,
		const QRectF &	rect
	)

protectedvirtual

Draw the Wheel's ticks

Parameters

painter	Painter
rect	Geometry for the wheel

◆ drawWheelBackground()

void QwtWheel::drawWheelBackground	(	QPainter *	painter,
		const QRectF &	rect
	)

protectedvirtual

Draw the Wheel's background gradient

Parameters

painter	Painter
rect	Geometry for the wheel

◆ isInverted()

bool QwtWheel::isInverted ( ) const

Returns: True, when the wheel is inverted

See also: setInverted()

◆ isTracking()

bool QwtWheel::isTracking ( ) const

Returns: True, when tracking is enabled

See also: setTracking(), valueChanged(), wheelMoved()

◆ keyPressEvent()

void QwtWheel::keyPressEvent ( QKeyEvent * event )

protectedvirtual

Handle key events

Qt::Key_Home
Step to minimum()
Qt::Key_End
Step to maximum()
Qt::Key_Up
In case of a horizontal or not inverted vertical wheel the value will be incremented by the step size. For an inverted vertical wheel the value will be decremented by the step size.
Qt::Key_Down
In case of a horizontal or not inverted vertical wheel the value will be decremented by the step size. For an inverted vertical wheel the value will be incremented by the step size.
Qt::Key_PageUp
The value will be incremented by pageStepSize() * singleStepSize().
Qt::Key_PageDown
The value will be decremented by pageStepSize() * singleStepSize().

Parameters

event Key event

◆ mass()

double QwtWheel::mass ( ) const

Returns: mass

See also: setMass()

◆ maximum()

double QwtWheel::maximum ( ) const

Returns: The maximum of the range

See also: setRange(), setMaximum(), minimum()

◆ minimum()

double QwtWheel::minimum ( ) const

Returns: The minimum of the range

See also: setRange(), setMinimum(), maximum()

◆ minimumSizeHint()

QSize QwtWheel::minimumSizeHint ( ) const

protectedvirtual

Returns: Minimum size hint

Warning: The return value is based on the wheel width.

◆ mouseMoveEvent()

void QwtWheel::mouseMoveEvent ( QMouseEvent * event )

protectedvirtual

Mouse Move Event handler.

Turn the wheel according to the mouse position

Parameters

event Mouse event

◆ mousePressEvent()

void QwtWheel::mousePressEvent ( QMouseEvent * event )

protectedvirtual

Mouse press event handler.

Start movement of the wheel.

Parameters

event Mouse event

◆ mouseReleaseEvent()

void QwtWheel::mouseReleaseEvent ( QMouseEvent * event )

protectedvirtual

Mouse Release Event handler.

When the wheel has no mass the movement of the wheel stops, otherwise it starts flying.

Parameters

event Mouse event

◆ orientation()

Qt::Orientation QwtWheel::orientation ( ) const

Returns: Orientation

See also: setOrientation()

◆ pageStepCount()

int QwtWheel::pageStepCount ( ) const

Returns: Page step count

See also: setPageStepCount(), singleStep()

◆ paintEvent()

void QwtWheel::paintEvent ( QPaintEvent * event )

protectedvirtual

Qt Paint Event.

Parameters

event Paint event

◆ setBorderWidth()

void QwtWheel::setBorderWidth ( int width )

Set the border width.

The border defaults to 2.

Parameters

width Border width

See also: borderWidth()

◆ setInverted()

void QwtWheel::setInverted ( bool on )

En/Disable inverted appearance.

An inverted wheel increases its values in the opposite direction. The direction of an inverted horizontal wheel will be from right to left an inverted vertical wheel will increase from bottom to top.

Parameters

on	En/Disable inverted appearance

See also: isInverted()

◆ setMass

void QwtWheel::setMass ( double mass )

slot

Set the slider's mass for flywheel effect.

If the slider's mass is greater then 0, it will continue to move after the mouse button has been released. Its speed decreases with time at a rate depending on the slider's mass. A large mass means that it will continue to move for a long time.

Derived widgets may overload this function to make it public.

Parameters

mass	New mass in kg

See also: mass()

◆ setMaximum()

void QwtWheel::setMaximum ( double value )

Set the maximum value of the range

Parameters

value Maximum value

See also: setRange(), setMinimum(), maximum()

◆ setMinimum()

void QwtWheel::setMinimum ( double value )

Set the minimum value of the range

Parameters

value Minimum value

See also: setRange(), setMaximum(), minimum()

Note: The maximum is adjusted if necessary to ensure that the range remains valid.

◆ setOrientation()

void QwtWheel::setOrientation ( Qt::Orientation orientation )

Set the wheel's orientation.

The default orientation is Qt::Horizontal.

Parameters

orientation Qt::Horizontal or Qt::Vertical.

See also: orientation()

◆ setPageStepCount()

void QwtWheel::setPageStepCount ( int count )

Set the page step count.

pageStepCount is a multiplicator for the single step size that typically corresponds to the user pressing PageUp or PageDown.

A value of 0 disables page stepping.

The default value is 1.

Parameters

count Multiplicator for the single step size

See also: pageStepCount(), setSingleStep()

◆ setRange()

void QwtWheel::setRange	(	double	min,
		double	max
	)

Set the minimum and maximum values.

The maximum is adjusted if necessary to ensure that the range remains valid. The value might be modified to be inside of the range.

Parameters

min	Minimum value
max	Maximum value

See also: minimum(), maximum()

◆ setSingleStep()

void QwtWheel::setSingleStep ( double stepSize )

Set the step size of the counter.

A value <= 0.0 disables stepping

Parameters

stepSize Single step size

See also: singleStep(), setPageStepCount()

◆ setStepAlignment()

void QwtWheel::setStepAlignment ( bool on )

En/Disable step alignment.

When step alignment is enabled value changes initiated by user input ( mouse, keyboard, wheel ) are aligned to the multiples of the single step.

Parameters

on On/Off

See also: stepAlignment(), setSingleStep()

◆ setTickCount()

void QwtWheel::setTickCount ( int count )

Adjust the number of grooves in the wheel's surface.

The number of grooves is limited to 6 <= count <= 50. Values outside this range will be clipped. The default value is 10.

Parameters

count Number of grooves per 360 degrees

See also: tickCount()

◆ setTotalAngle

void QwtWheel::setTotalAngle ( double angle )

slot

Set the total angle which the wheel can be turned.

One full turn of the wheel corresponds to an angle of 360 degrees. A total angle of n*360 degrees means that the wheel has to be turned n times around its axis to get from the minimum value to the maximum value.

The default setting of the total angle is 360 degrees.

Parameters

angle total angle in degrees

See also: totalAngle()

◆ setTracking()

void QwtWheel::setTracking ( bool enable )

En/Disable tracking.

If tracking is enabled (the default), the wheel emits the valueChanged() signal while the wheel is moving. If tracking is disabled, the wheel emits the valueChanged() signal only when the wheel movement is terminated.

The wheelMoved() signal is emitted regardless id tracking is enabled or not.

Parameters

enable On/Off

See also: isTracking()

◆ setUpdateInterval()

void QwtWheel::setUpdateInterval ( int interval )

Specify the update interval when the wheel is flying.

Default and minimum value is 50 ms.

Parameters

interval Interval in milliseconds

See also: updateInterval(), setMass(), setTracking()

◆ setValue

void QwtWheel::setValue ( double value )

slot

Set a new value without adjusting to the step raster.

Parameters

value New value

See also: value(), valueChanged()

Warning: The value is clipped when it lies outside the range.

◆ setViewAngle

void QwtWheel::setViewAngle ( double angle )

slot

Specify the visible portion of the wheel.

You may use this function for fine-tuning the appearance of the wheel. The default value is 175 degrees. The value is limited from 10 to 175 degrees.

Parameters

angle Visible angle in degrees

See also: viewAngle(), setTotalAngle()

◆ setWheelBorderWidth()

void QwtWheel::setWheelBorderWidth ( int borderWidth )

Set the wheel border width of the wheel.

The wheel border must not be smaller than 1 and is limited in dependence on the wheel's size. Values outside the allowed range will be clipped.

The wheel border defaults to 2.

Parameters

borderWidth Border width

See also: internalBorder()

◆ setWheelWidth()

void QwtWheel::setWheelWidth ( int width )

Set the width of the wheel.

Corresponds to the wheel height for horizontal orientation, and the wheel width for vertical orientation.

Parameters

width the wheel's width

See also: wheelWidth()

◆ setWrapping()

void QwtWheel::setWrapping ( bool on )

En/Disable wrapping.

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

Parameters

on	En/Disable wrapping

See also: wrapping()

◆ singleStep()

double QwtWheel::singleStep ( ) const

Returns: Single step size

See also: setSingleStep()

◆ sizeHint()

QSize QwtWheel::sizeHint ( ) const

protectedvirtual

Returns: a size hint

◆ stepAlignment()

bool QwtWheel::stepAlignment ( ) const

Returns: True, when the step alignment is enabled

See also: setStepAlignment(), singleStep()

◆ tickCount()

int QwtWheel::tickCount ( ) const

Returns: Number of grooves in the wheel's surface.

See also: setTickCnt()

◆ timerEvent()

void QwtWheel::timerEvent ( QTimerEvent * event )

protectedvirtual

Qt timer event.

The flying wheel effect is implemented using a timer

Parameters

event Timer event

See also: updateInterval()

◆ totalAngle()

double QwtWheel::totalAngle ( ) const

Returns: Total angle which the wheel can be turned.

See also: setTotalAngle()

◆ updateInterval()

int QwtWheel::updateInterval ( ) const

Returns: Update interval when the wheel is flying

See also: setUpdateInterval(), mass(), isTracking()

◆ value()

double QwtWheel::value ( ) const

Returns: Current value of the wheel

See also: setValue(), valueChanged()

◆ valueAt()

double QwtWheel::valueAt ( const QPoint & pos ) const

protectedvirtual

Determine the value corresponding to a specified point

Parameters

pos Position

Returns: Value corresponding to pos

◆ valueChanged

void QwtWheel::valueChanged ( double value )

signal

Notify a change of value.

When tracking is enabled this signal will be emitted every time the value changes.

Parameters

value new value

See also: setTracking()

◆ viewAngle()

double QwtWheel::viewAngle ( ) const

Returns: Visible portion of the wheel

See also: setViewAngle(), totalAngle()

◆ wheelBorderWidth()

int QwtWheel::wheelBorderWidth ( ) const

Returns: Wheel border width

See also: setWheelBorderWidth()

◆ wheelEvent()

void QwtWheel::wheelEvent ( QWheelEvent * event )

protectedvirtual

Handle wheel events.

In/Decrement the value

Parameters

event Wheel event

◆ wheelMoved

void QwtWheel::wheelMoved ( double value )

signal

This signal is emitted when the user moves the wheel with the mouse.

Parameters

value new value

◆ wheelPressed

void QwtWheel::wheelPressed ( )

signal

This signal is emitted when the user presses the the wheel with the mouse

◆ wheelRect()

QRect QwtWheel::wheelRect ( ) const

protected

Returns: Rectangle of the wheel without the outer border

◆ wheelReleased

void QwtWheel::wheelReleased ( )

signal

This signal is emitted when the user releases the mouse

◆ wheelWidth()

int QwtWheel::wheelWidth ( ) const

Returns: Width of the wheel

See also: setWheelWidth()

◆ wrapping()

bool QwtWheel::wrapping ( ) const

Returns: True, when wrapping is set

See also: setWrapping()

Public Slots

Signals

Public Member Functions

Protected Member Functions

Detailed Description

Member Function Documentation

◆ borderWidth()

◆ drawTicks()

◆ drawWheelBackground()

◆ isInverted()

◆ isTracking()

◆ keyPressEvent()

◆ mass()

◆ maximum()

◆ minimum()

◆ minimumSizeHint()

◆ mouseMoveEvent()

◆ mousePressEvent()

◆ mouseReleaseEvent()

◆ orientation()

◆ pageStepCount()

◆ paintEvent()

◆ setBorderWidth()

◆ setInverted()

◆ setMass

◆ setMaximum()

◆ setMinimum()

◆ setOrientation()

◆ setPageStepCount()

◆ setRange()

◆ setSingleStep()

◆ setStepAlignment()

◆ setTickCount()

◆ setTotalAngle

◆ setTracking()

◆ setUpdateInterval()

◆ setValue

◆ setViewAngle

◆ setWheelBorderWidth()

◆ setWheelWidth()

◆ setWrapping()

◆ singleStep()

◆ sizeHint()

◆ stepAlignment()

◆ tickCount()

◆ timerEvent()

◆ totalAngle()

◆ updateInterval()

◆ value()

◆ valueAt()

◆ valueChanged

◆ viewAngle()

◆ wheelBorderWidth()

◆ wheelEvent()

◆ wheelMoved

◆ wheelPressed

◆ wheelRect()

◆ wheelReleased

◆ wheelWidth()

◆ wrapping()