QwtCounter - Man Page

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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Info

Mon Jun 1 2020 Version 6.1.5 Qwt User's Guide