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

#include <qwt_abstract_slider.h>

Inheritance diagram for QwtAbstractSlider:

[legend]

Public Slots
void	setValue (double val)

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

void	sliderPressed ()

void	sliderReleased ()

void	sliderMoved (double value)

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

virtual	~QwtAbstractSlider ()
	Destructor.

void	setValid (bool)

bool	isValid () const

double	value () const
	Returns the current value.

void	setWrapping (bool)

bool	wrapping () const

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

uint	totalSteps () const

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

uint	singleSteps () const

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

uint	pageSteps () const

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

bool	stepAlignment () const

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

bool	isTracking () const

void	setReadOnly (bool)

bool	isReadOnly () const

void	setInvertedControls (bool)

bool	invertedControls () const

Public Member Functions inherited from QwtAbstractScale
	QwtAbstractScale (QWidget *parent=NULL)

virtual	~QwtAbstractScale ()
	Destructor.

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...

const QwtScaleDiv &	scaleDiv () const

void	setLowerBound (double value)

double	lowerBound () const

void	setUpperBound (double value)

double	upperBound () const

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

double	scaleStepSize () const

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

int	scaleMaxMinor () const

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

int	scaleMaxMajor () const

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

const QwtScaleEngine *	scaleEngine () const

QwtScaleEngine *	scaleEngine ()

int	transform (double) const

double	invTransform (int) const

bool	isInverted () const

double	minimum () const

double	maximum () const

const QwtScaleMap &	scaleMap () const

Protected Member Functions
virtual void	mousePressEvent (QMouseEvent *)

virtual void	mouseReleaseEvent (QMouseEvent *)

virtual void	mouseMoveEvent (QMouseEvent *)

virtual void	keyPressEvent (QKeyEvent *)

virtual void	wheelEvent (QWheelEvent *)

virtual bool	isScrollPosition (const QPoint &pos) const =0
	Determine what to do when the user presses a mouse button. More...

virtual double	scrolledTo (const QPoint &pos) const =0
	Determine the value for a new position of the movable part of the slider. More...

void	incrementValue (int numSteps)

virtual void	scaleChange ()

virtual void	sliderChange ()
	Calling update()

double	incrementedValue (double value, int stepCount) const

Protected Member Functions inherited from QwtAbstractScale
void	rescale (double lowerBound, double upperBound, double stepSize)

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

const QwtAbstractScaleDraw *	abstractScaleDraw () const

QwtAbstractScaleDraw *	abstractScaleDraw ()

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 nor 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 ( QWidget * parent = NULL )

explicit

Constructor.

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

The initial value is invalid.

Parameters

parent Parent widget

Member Function Documentation

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

protected

Increment a value

Parameters

value	Value
stepCount	Number of steps

Returns: Incremented value

void QwtAbstractSlider::incrementValue ( int stepCount )

protected

Increment the slider

The step size depends on the number of totalSteps()

Parameters

stepCount Number of steps

See also: setTotalSteps(), incrementedValue()

bool QwtAbstractSlider::invertedControls ( ) const

Returns: True, when the controls are inverted

See also: setInvertedControls()

bool QwtAbstractSlider::isReadOnly ( ) const

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

Returns: true if read only

See also: setReadOnly()

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

protectedpure virtual

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

Parameters

pos	Mouse position

Return values

True,when pos is a valid scroll position

See also: scrolledTo()

Implemented in QwtKnob, QwtDial, and QwtSlider.

bool QwtAbstractSlider::isTracking ( ) const

Returns: True, when tracking has been enabled

See also: setTracking()

bool QwtAbstractSlider::isValid ( ) const

Returns: True, when the value is invalid

void QwtAbstractSlider::keyPressEvent ( QKeyEvent * event )

protectedvirtual

Handles key 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()

Reimplemented in QwtCompass.

void QwtAbstractSlider::mouseMoveEvent ( QMouseEvent * event )

protectedvirtual

Mouse Move Event handler

Parameters

event Mouse event

void QwtAbstractSlider::mousePressEvent ( QMouseEvent * event )

protectedvirtual

Mouse press event handler

Parameters

event Mouse event

Reimplemented in QwtSlider.

void QwtAbstractSlider::mouseReleaseEvent ( QMouseEvent * event )

protectedvirtual

Mouse Release Event handler

Parameters

event Mouse event

Reimplemented in QwtSlider.

uint QwtAbstractSlider::pageSteps ( ) const

Returns: Number of steps

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

void QwtAbstractSlider::scaleChange ( )

protectedvirtual

Update the slider according to modifications of the scale

Reimplemented from QwtAbstractScale.

Reimplemented in QwtDial, and QwtSlider.

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

protectedpure virtual

Determine the value for a new position of the movable part of the slider.

Parameters

pos	Mouse position

Returns: Value for the mouse position

See also: isScrollPosition()

Implemented in QwtKnob, QwtDial, and QwtSlider.

void QwtAbstractSlider::setInvertedControls ( bool on )

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()

void QwtAbstractSlider::setPageSteps ( uint stepCount )

Set the number of steps for a page increment.

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

Parameters

stepCount Number of steps

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

void QwtAbstractSlider::setReadOnly ( bool on )

En/Disable read only mode

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

Parameters

on	Enables in case of true

See also: isReadOnly()

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

void QwtAbstractSlider::setSingleSteps ( uint stepCount )

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

stepCount Number of steps

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

void QwtAbstractSlider::setStepAlignment ( bool on )

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()

void QwtAbstractSlider::setTotalSteps ( uint stepCount )

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

stepCount Number of steps

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

void QwtAbstractSlider::setTracking ( bool on )

Enables or disables 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` (enable) or `false` (disable) tracking.

See also: isTracking(), sliderMoved()

void QwtAbstractSlider::setValid ( bool on )

Set the value to be valid/invalid

Parameters

on	When true, the value is invalidated

See also: setValue()

void QwtAbstractSlider::setValue ( double value )

slot

Set the slider to the specified value

Parameters

value New value

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

void QwtAbstractSlider::setWrapping ( bool on )

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

Parameters

on	En/Disable wrapping

See also: wrapping()

uint QwtAbstractSlider::singleSteps ( ) const

Returns: Number of steps

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

void QwtAbstractSlider::sliderMoved ( double value )

signal

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

Parameters

value New value

See also: valueChanged()

void QwtAbstractSlider::sliderPressed ( )

signal

This signal is emitted when the user presses the movable part of the slider.

void QwtAbstractSlider::sliderReleased ( )

signal

This signal is emitted when the user releases the movable part of the slider.

bool QwtAbstractSlider::stepAlignment ( ) const

Returns: True, when step alignment is enabled

See also: setStepAlignment()

uint QwtAbstractSlider::totalSteps ( ) const

Returns: Number of steps

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

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()

void QwtAbstractSlider::wheelEvent ( QWheelEvent * event )

protectedvirtual

Wheel Event handler

In/decreases the value by s 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

Reimplemented in QwtDial.

bool QwtAbstractSlider::wrapping ( ) const

Returns: True, when wrapping is set

See also: setWrapping()

Public Slots

Signals

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation