QwtCounter.qt5 - Man Page


#include <qwt_counter.h>

Inherits QwtDoubleRange.

Public Types

enum Button { Button1, Button2, Button3, ButtonCnt }


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

Public Member Functions

QwtCounter (QWidget *parent=NULL)
virtual ~QwtCounter ()
bool editable () const
int incSteps (QwtCounter::Button btn) const
double maxVal () const
double minVal () const
int numButtons () const
virtual void polish ()
void setEditable (bool)
void setIncSteps (QwtCounter::Button btn, int nSteps)
void setMaxValue (double m)
void setMinValue (double m)
void setNumButtons (int n)
void setStep (double s)
void setStepButton1 (int nSteps)
void setStepButton2 (int nSteps)
void setStepButton3 (int nSteps)
virtual void setValue (double)
virtual QSize sizeHint () const
double step () const
int stepButton1 () const
int stepButton2 () const
int stepButton3 () const
virtual double value () const

Protected Member Functions

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

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. The range can be specified using QwtDblRange::setRange(). The counter's value is an integer multiple of the step size. The number of steps by which a button increments or decrements the value can be specified using QwtCounter::setIncSteps(). The number of buttons can be changed with QwtCounter::setNumButtons().

Holding the space bar down with focus on a button is the fastest method to step through the counter values. When the counter underflows/overflows, the focus is set to the smallest up/down button and counting is disabled. Counting is re-enabled on a button release event (mouse or space bar).


#include '../include/qwt_counter.h>

QwtCounter *cnt;

cnt = new QwtCounter(parent, name);

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

connect(cnt, SIGNAL(valueChanged(double)), my_class, SLOT(newValue(double)));

Member Enumeration Documentation

enum QwtCounter::Button

Button index

Constructor & Destructor Documentation

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

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


Member Function Documentation

void QwtCounter::buttonReleased (doublevalue) [signal]

This signal is emitted when a button has been released


value The new value

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

Handle PolishRequest events

int QwtCounter::incSteps (QwtCounter::Buttonbtn) const


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


btn One of QwtCounter::Button1, QwtCounter::Button2, QwtCounter::Button3

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

Handle key events

  • Ctrl + Qt::Key_Home Step to minValue()
  • Ctrl + Qt::Key_End Step to maxValue()
  • 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)

int QwtCounter::numButtons () const


The number of buttons on each side of the widget.

void QwtCounter::polish () [virtual]

Sets the minimum width for the buttons

void QwtCounter::rangeChange () [protected], [virtual]

Notify change of range. This function updates the enabled property of all buttons contained in QwtCounter.

Reimplemented from QwtDoubleRange.

void QwtCounter::setEditable (booleditable)

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

editable true enables editing

See also:


void QwtCounter::setIncSteps (QwtCounter::Buttonbtn, intnSteps)

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


btn One of QwtCounter::Button1, QwtCounter::Button2, QwtCounter::Button3
nSteps Number of steps

void QwtCounter::setMaxValue (doublevalue)

Set the maximum value of the range


value Maximum value

See also:

setMinValue(), maxVal()

void QwtCounter::setMinValue (doublevalue)

Set the minimum value of the range


value Minimum value

See also:

setMaxValue(), minVal()

void QwtCounter::setNumButtons (intn)

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

n Number of buttons

void QwtCounter::setStep (doublestepSize)

Set the step size


stepSize Step size

See also:


Reimplemented from QwtDoubleRange.

void QwtCounter::setStepButton1 (intnSteps)

Set the number of increment steps for button 1


nSteps Number of steps

void QwtCounter::setStepButton2 (intnSteps)

Set the number of increment steps for button 2


nSteps Number of steps

void QwtCounter::setStepButton3 (intnSteps)

Set the number of increment steps for button 3


nSteps Number of steps

void QwtCounter::setValue (doublev) [virtual]

Set a new value. Parameters:

v new value Calls QwtDoubleRange::setValue and does all visual updates.

See also:


Reimplemented from QwtDoubleRange.

double QwtCounter::value () const [virtual]


Current value

Reimplemented from QwtDoubleRange.

void QwtCounter::valueChanged (doublevalue) [signal]

This signal is emitted when the counter's value has changed


value The new value

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

Handle wheel events


e Wheel event


Generated automatically by Doxygen for Qwt User's Guide from the source code.


Tue Nov 20 2012 Version 5.2.3 Qwt User's Guide