Qwt User's Guide  5.2.3
Public Types | Signals | Public Member Functions | Protected Member Functions
QwtCounter Class Reference

#include <qwt_counter.h>

Inheritance diagram for QwtCounter:
Inheritance graph
[legend]

List of all members.

Public Types

enum  Button {
  Button1,
  Button2,
  Button3,
  ButtonCnt
}

Signals

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
- Public Member Functions inherited from QwtDoubleRange
 QwtDoubleRange ()
virtual ~QwtDoubleRange ()
virtual void fitValue (double)
virtual void incPages (int)
virtual void incValue (int)
bool isValid () const
double maxValue () const
double minValue () const
int pageSize () const
bool periodic () const
void setPeriodic (bool tf)
void setRange (double vmin, double vmax, double vstep=0.0, int pagesize=1)
void setValid (bool)

Protected Member Functions

virtual bool event (QEvent *)
virtual void keyPressEvent (QKeyEvent *)
virtual void rangeChange ()
virtual void wheelEvent (QWheelEvent *)
- Protected Member Functions inherited from QwtDoubleRange
double exactPrevValue () const
double exactValue () const
double prevValue () const
virtual void stepChange ()

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).

Example:

#include "../include/qwt_counter.h>
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

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
Parameters:
parent

Member Function Documentation

void QwtCounter::buttonReleased ( double  value)
signal

This signal is emitted when a button has been released

Parameters:
valueThe new value
bool QwtCounter::event ( QEvent *  e)
protectedvirtual

Handle PolishRequest events

int QwtCounter::incSteps ( QwtCounter::Button  btn) const
Returns:
the number of steps by which a specified button increments the value or 0 if the button is invalid.
Parameters:
btnOne of QwtCounter::Button1, QwtCounter::Button2, QwtCounter::Button3
void QwtCounter::keyPressEvent ( QKeyEvent *  e)
protectedvirtual

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
Returns:
The number of buttons on each side of the widget.
void QwtCounter::polish ( )
virtual

Sets the minimum width for the buttons

void QwtCounter::rangeChange ( )
protectedvirtual

Notify change of range.

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

Reimplemented from QwtDoubleRange.

void QwtCounter::setEditable ( bool  editable)

Allow/disallow the user to manually edit the value.

Parameters:
editabletrue enables editing
See also:
editable()
void QwtCounter::setIncSteps ( QwtCounter::Button  btn,
int  nSteps 
)

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

Parameters:
btnOne of QwtCounter::Button1, QwtCounter::Button2, QwtCounter::Button3
nStepsNumber of steps
void QwtCounter::setMaxValue ( double  value)

Set the maximum value of the range

Parameters:
valueMaximum value
See also:
setMinValue(), maxVal()
void QwtCounter::setMinValue ( double  value)

Set the minimum value of the range

Parameters:
valueMinimum value
See also:
setMaxValue(), minVal()
void QwtCounter::setNumButtons ( int  n)

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

Parameters:
nNumber of buttons
void QwtCounter::setStep ( double  stepSize)

Set the step size

Parameters:
stepSizeStep size
See also:
QwtDoubleRange::setStep()

Reimplemented from QwtDoubleRange.

void QwtCounter::setStepButton1 ( int  nSteps)

Set the number of increment steps for button 1

Parameters:
nStepsNumber of steps
void QwtCounter::setStepButton2 ( int  nSteps)

Set the number of increment steps for button 2

Parameters:
nStepsNumber of steps
void QwtCounter::setStepButton3 ( int  nSteps)

Set the number of increment steps for button 3

Parameters:
nStepsNumber of steps
void QwtCounter::setValue ( double  v)
virtual

Set a new value.

Parameters:
vnew value Calls QwtDoubleRange::setValue and does all visual updates.
See also:
QwtDoubleRange::setValue()

Reimplemented from QwtDoubleRange.

double QwtCounter::value ( ) const
virtual
Returns:
Current value

Reimplemented from QwtDoubleRange.

void QwtCounter::valueChanged ( double  value)
signal

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

Parameters:
valueThe new value
void QwtCounter::wheelEvent ( QWheelEvent *  e)
protectedvirtual

Handle wheel events

Parameters:
eWheel event