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 val)
Signals
void	sliderMoved (double value)
void	sliderPressed ()
void	sliderReleased ()
void	valueChanged (double value)
	Notify a change of value.
Public Member Functions
bool	invertedControls () const
bool	isReadOnly () const
bool	isTracking () const
bool	isValid () const
uint	pageSteps () const
	QwtAbstractSlider (QWidget *parent=NULL)
	Constructor.
void	setInvertedControls (bool)
void	setPageSteps (uint)
	Set the number of steps for a page increment.
void	setReadOnly (bool)
void	setSingleSteps (uint)
	Set the number of steps for a single increment.
void	setStepAlignment (bool)
	Enable step alignment.
void	setTotalSteps (uint)
	Set the number of steps.
void	setTracking (bool)
	Enables or disables tracking.
void	setValid (bool)
void	setWrapping (bool)
uint	singleSteps () const
bool	stepAlignment () const
uint	totalSteps () const
double	value () const
bool	wrapping () const
virtual	~QwtAbstractSlider ()
	Destructor.
Protected Member Functions
double	incrementedValue (double value, int stepCount) const
void	incrementValue (int numSteps)
virtual bool	isScrollPosition (const QPoint &pos) const =0
	Determine what to do when the user presses a mouse button.
virtual void	keyPressEvent (QKeyEvent *)
virtual void	mouseMoveEvent (QMouseEvent *)
virtual void	mousePressEvent (QMouseEvent *)
virtual void	mouseReleaseEvent (QMouseEvent *)
virtual void	scaleChange ()
virtual double	scrolledTo (const QPoint &pos) const =0
	Determine the value for a new position of the movable part of the slider.
virtual void	sliderChange ()
	Calling update()
virtual void	wheelEvent (QWheelEvent *)
Properties
bool	invertedControls
uint	pageSteps
bool	readOnly
uint	singleSteps
bool	stepAlignment
uint	totalSteps
bool	tracking
double	value
	Returns the current value.
bool	wrapping
Private Member Functions
double	alignedValue (double) const
double	boundedValue (double) const
Private Attributes
PrivateData *	d_data

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.

Definition at line 32 of file qwt_abstract_slider.h.

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

Definition at line 94 of file qwt_abstract_slider.cpp.

QwtAbstractSlider::~QwtAbstractSlider ( ) [virtual]

Destructor.

Definition at line 104 of file qwt_abstract_slider.cpp.

Member Function Documentation

double QwtAbstractSlider::alignedValue ( double value ) const [private]

Definition at line 747 of file qwt_abstract_slider.cpp.

double QwtAbstractSlider::boundedValue ( double value ) const [private]

Definition at line 707 of file qwt_abstract_slider.cpp.

double QwtAbstractSlider::incrementedValue	(	double	value,
		int	stepCount
	)		const `[protected]`

Increment a value

Parameters:

value	Value
stepCount	Number of steps

Returns:: Incremented value

Definition at line 665 of file qwt_abstract_slider.cpp.

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()

Definition at line 645 of file qwt_abstract_slider.cpp.

bool QwtAbstractSlider::invertedControls ( ) const

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()

Definition at line 162 of file qwt_abstract_slider.cpp.

virtual bool QwtAbstractSlider::isScrollPosition ( const QPoint & pos ) const [protected, pure 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()

Definition at line 189 of file qwt_abstract_slider.cpp.

bool QwtAbstractSlider::isValid ( ) const

Returns:: True, when the value is invalid

Definition at line 128 of file qwt_abstract_slider.cpp.

void QwtAbstractSlider::keyPressEvent ( QKeyEvent * event ) [protected, virtual]

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.

Definition at line 365 of file qwt_abstract_slider.cpp.

void QwtAbstractSlider::mouseMoveEvent ( QMouseEvent * event ) [protected, virtual]

Mouse Move Event handler

Parameters:

event Mouse event

Definition at line 223 of file qwt_abstract_slider.cpp.

void QwtAbstractSlider::mousePressEvent ( QMouseEvent * event ) [protected, virtual]

Mouse press event handler

Parameters:

event Mouse event

Reimplemented in QwtSlider.

Definition at line 198 of file qwt_abstract_slider.cpp.

void QwtAbstractSlider::mouseReleaseEvent ( QMouseEvent * event ) [protected, virtual]

Mouse Release Event handler

Parameters:

event Mouse event

Reimplemented in QwtSlider.

Definition at line 268 of file qwt_abstract_slider.cpp.

uint QwtAbstractSlider::pageSteps ( ) const

void QwtAbstractSlider::scaleChange ( ) [protected, virtual]

Update the slider according to modifications of the scale

Reimplemented from QwtAbstractScale.

Reimplemented in QwtDial, and QwtSlider.

Definition at line 801 of file qwt_abstract_slider.cpp.

virtual double QwtAbstractSlider::scrolledTo ( const QPoint & pos ) const [protected, pure 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()

Definition at line 623 of file qwt_abstract_slider.cpp.

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()

Definition at line 519 of file qwt_abstract_slider.cpp.

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

Definition at line 144 of file qwt_abstract_slider.cpp.

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()

Definition at line 494 of file qwt_abstract_slider.cpp.

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()

Definition at line 542 of file qwt_abstract_slider.cpp.

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()

Definition at line 469 of file qwt_abstract_slider.cpp.

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()

Definition at line 180 of file qwt_abstract_slider.cpp.

void QwtAbstractSlider::setValid ( bool on )

Set the value to be valid/invalid

Parameters:

on	When true, the value is invalidated

See also:: setValue()

Definition at line 116 of file qwt_abstract_slider.cpp.

void QwtAbstractSlider::setValue ( double value ) [slot]

Set the slider to the specified value

Parameters:

value New value

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

Definition at line 565 of file qwt_abstract_slider.cpp.

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()

Definition at line 594 of file qwt_abstract_slider.cpp.

uint QwtAbstractSlider::singleSteps ( ) const

void QwtAbstractSlider::sliderChange ( ) [protected, virtual]

Calling update()

Reimplemented in QwtDial.

Definition at line 819 of file qwt_abstract_slider.cpp.

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

uint QwtAbstractSlider::totalSteps ( ) const

double QwtAbstractSlider::value ( ) const

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 ) [protected, virtual]

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.

Definition at line 299 of file qwt_abstract_slider.cpp.

bool QwtAbstractSlider::wrapping ( ) const