QwtCounter(3)

The Counter Widget.

Section 3 libqwt-doc bookworm source

Description

QwtCounter

NAME

QwtCounter - The Counter Widget.

SYNOPSIS

#include <qwt_counter.h>

Inherits QWidget.

Public Types

enum Button { Button1, Button2, Button3, ButtonCnt }
Button index.

Public Slots

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

Signals

void buttonReleased (double value)
void valueChanged (double value)

Public Member Functions

QwtCounter (QWidget *parent=NULL)
virtual ˜QwtCounter ()
Destructor.
void setValid (bool)
bool isValid () const
void setWrapping (bool)
En/Disable wrapping.
bool wrapping () const
bool isReadOnly () const
void setReadOnly (bool)
Allow/disallow the user to manually edit the value.
void setNumButtons (int)
int numButtons () const
void setIncSteps (QwtCounter::Button, int numSteps)
int incSteps (QwtCounter::Button) const
virtual QSize sizeHint () const
A size hint.
double singleStep () const
void setSingleStep (double stepSize)
Set the step size of the counter.
void setRange (double min, double max)
Set the minimum and maximum values.
double minimum () const
void setMinimum (double)
double maximum () const
void setMaximum (double)
void setStepButton1 (int nSteps)
int stepButton1 () const
returns the number of increment steps for button 1
void setStepButton2 (int nSteps)
int stepButton2 () const
returns the number of increment steps for button 2
void setStepButton3 (int nSteps)
int stepButton3 () const
returns the number of increment steps for button 3
double value () const

Protected Member Functions

virtual bool event (QEvent *)
virtual void wheelEvent (QWheelEvent *)
virtual void keyPressEvent (QKeyEvent *)

Detailed Description

The Counter Widget.

A Counter consists of a label displaying a number and one ore more (up to three) push buttons on each side of the label which can be used to increment or decrement the counter’s value.

A counter has a range from a minimum value to a maximum value and a step size. When the wrapping property is set the counter is circular.

The number of steps by which a button increments or decrements the value can be specified using setIncSteps(). The number of buttons can be changed with setNumButtons().

Example:

#include <qwt_counter.h>

QwtCounter *counter = new QwtCounter(parent);

counter->setRange(0.0, 100.0); // From 0.0 to 100
counter->setSingleStep( 1.0 ); // Step size 1.0
counter->setNumButtons(2); // Two buttons each side
counter->setIncSteps(QwtCounter::Button1, 1); // Button 1 increments 1 step
counter->setIncSteps(QwtCounter::Button2, 20); // Button 2 increments 20 steps

connect(counter, SIGNAL(valueChanged(double)), myClass, SLOT(newValue(double)));

Member Enumeration Documentation

enum QwtCounter::Button

Button index.

Enumerator
Button1

Button intended for minor steps.

Button2

Button intended for medium steps.

Button3

Button intended for large steps.

ButtonCnt

Number of buttons.

Constructor & Destructor Documentation

QwtCounter::QwtCounter (QWidget * parent = NULL) [explicit]

The counter is initialized with a range is set to [0.0, 1.0] with 0.01 as single step size. The value is invalid.

The default number of buttons is set to 2. The default increments are:

	•		Button 1: 1 step
	•		Button 2: 10 steps
	•		Button 3: 100 steps

Parameters:

parent

Member Function Documentation

void QwtCounter::buttonReleased (double value) [signal]

This signal is emitted when a button has been released
Parameters:

value The new value

bool QwtCounter::event (QEvent * event) [protected], [virtual]

Handle QEvent::PolishRequest events
Parameters:

event Event

Returns:

see QWidget::event()

int QwtCounter::incSteps (QwtCounter::Button button) const

Returns:

The number of steps by which a specified button increments the value or 0 if the button is invalid.

Parameters:

button Button index

See also:

setIncSteps()

bool QwtCounter::isReadOnly () const

Returns:

True, when the line line edit is read only. (default is no)

See also:

setReadOnly()

bool QwtCounter::isValid () const

Returns:

True, if the value is valid

See also:

setValid(), setValue()

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

Handle key events

•

Ctrl + Qt::Key_Home

Step to minimum()

•

Ctrl + Qt::Key_End

Step to maximum()

•

Qt::Key_Up

Increment by incSteps(QwtCounter::Button1)

•

Qt::Key_Down

Decrement by incSteps(QwtCounter::Button1)

•

Qt::Key_PageUp

Increment by incSteps(QwtCounter::Button2)

•

Qt::Key_PageDown

Decrement by incSteps(QwtCounter::Button2)

•

Shift + Qt::Key_PageUp

Increment by incSteps(QwtCounter::Button3)

•

Shift + Qt::Key_PageDown

Decrement by incSteps(QwtCounter::Button3)

Parameters:

event Key event

double QwtCounter::maximum () const

Returns:

The maximum of the range

See also:

setRange(), setMaximum(), minimum()

double QwtCounter::minimum () const

Returns:

The minimum of the range

See also:

setRange(), setMinimum(), maximum()

int QwtCounter::numButtons () const

Returns:

The number of buttons on each side of the widget.

See also:

setNumButtons()

void QwtCounter::setIncSteps (QwtCounter::Button button, int numSteps)

Specify the number of steps by which the value is incremented or decremented when a specified button is pushed.
Parameters:

button Button index
numSteps Number of steps

See also:

incSteps()

void QwtCounter::setMaximum (double value)

Set the maximum value of the range
Parameters:

value Maximum value

See also:

setRange(), setMinimum(), maximum()

void QwtCounter::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.

void QwtCounter::setNumButtons (int numButtons)

Specify the number of buttons on each side of the label
Parameters:

numButtons Number of buttons

See also:

numButtons()

void QwtCounter::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()

void QwtCounter::setReadOnly (bool on)

Allow/disallow the user to manually edit the value.
Parameters:

on True disable editing

See also:

isReadOnly()

void QwtCounter::setSingleStep (double stepSize)

Set the step size of the counter. A value <= 0.0 disables stepping
Parameters:

stepSize Single step size

See also:

singleStep()

void QwtCounter::setStepButton1 (int nSteps)

Set the number of increment steps for button 1
Parameters:

nSteps Number of steps

void QwtCounter::setStepButton2 (int nSteps)

Set the number of increment steps for button 2
Parameters:

nSteps Number of steps

void QwtCounter::setStepButton3 (int nSteps)

Set the number of increment steps for button 3
Parameters:

nSteps Number of steps

void QwtCounter::setValid (bool on)

Set the counter to be in valid/invalid state
When the counter is set to invalid, no numbers are displayed and the buttons are disabled.
Parameters:

on If true the counter will be set as valid

See also:

setValue(), isValid()

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

Set a new value without adjusting to the step raster. The state of the counter is set to be valid.
Parameters:

value New value

See also:

isValid(), value(), valueChanged()

Warning:

The value is clipped when it lies outside the range.

void QwtCounter::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()

double QwtCounter::singleStep () const

Returns:

Single step size

See also:

setSingleStep()

double QwtCounter::value () const

Returns:

Current value of the counter

See also:

setValue(), valueChanged()

void QwtCounter::valueChanged (double value) [signal]

This signal is emitted when the counter’s value has changed
Parameters:

value The new value

void QwtCounter::wheelEvent (QWheelEvent * event) [protected], [virtual]

Handle wheel events
Parameters:

event Wheel event

bool QwtCounter::wrapping () const

Returns:

True, when wrapping is set

See also:

setWrapping()

Author

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