Qwt User's Guide  6.2.0
QwtCounter Class Reference

The Counter Widget. More...

#include <qwt_counter.h>

Inheritance diagram for QwtCounter:

Public Types

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

Public Slots

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

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. More...
 
bool wrapping () const
 
bool isReadOnly () const
 
void setReadOnly (bool)
 Allow/disallow the user to manually edit the value. More...
 
void setNumButtons (int)
 
int numButtons () const
 
void setIncSteps (QwtCounter::Button, int numSteps)
 
int incSteps (QwtCounter::Button) const
 
virtual QSize sizeHint () const override
 A size hint.
 
double singleStep () const
 
void setSingleStep (double stepSize)
 Set the step size of the counter. More...
 
void setRange (double min, double max)
 Set the minimum and maximum values. More...
 
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 *) override
 
virtual void wheelEvent (QWheelEvent *) override
 
virtual void keyPressEvent (QKeyEvent *) override
 

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)));
The Counter Widget.
Definition: qwt_counter.h:49
@ Button1
Button intended for minor steps.
Definition: qwt_counter.h:70
@ Button2
Button intended for medium steps.
Definition: qwt_counter.h:73
void setNumButtons(int)
void setIncSteps(QwtCounter::Button, int numSteps)
void setRange(double min, double max)
Set the minimum and maximum values.
void valueChanged(double value)
QwtCounter(QWidget *parent=NULL)
Definition: qwt_counter.cpp:65
void setSingleStep(double stepSize)
Set the step size of the counter.

Definition at line 48 of file qwt_counter.h.

Member Enumeration Documentation

◆ 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.

Definition at line 67 of file qwt_counter.h.

Constructor & Destructor Documentation

◆ QwtCounter()

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

Definition at line 65 of file qwt_counter.cpp.

Member Function Documentation

◆ buttonReleased

void QwtCounter::buttonReleased ( double  value)
signal

This signal is emitted when a button has been released

Parameters
valueThe new value

◆ event()

bool QwtCounter::event ( QEvent *  event)
overrideprotectedvirtual

Handle QEvent::PolishRequest events

Parameters
eventEvent
Returns
see QWidget::event()

Definition at line 485 of file qwt_counter.cpp.

◆ incSteps()

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
buttonButton index
See also
setIncSteps()

Definition at line 416 of file qwt_counter.cpp.

◆ isReadOnly()

bool QwtCounter::isReadOnly ( ) const
Returns
True, when the line line edit is read only. (default is no)
See also
setReadOnly()

Definition at line 186 of file qwt_counter.cpp.

◆ isValid()

bool QwtCounter::isValid ( ) const
Returns
True, if the value is valid
See also
setValid(), setValue()

Definition at line 166 of file qwt_counter.cpp.

◆ keyPressEvent()

void QwtCounter::keyPressEvent ( QKeyEvent *  event)
overrideprotectedvirtual

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
eventKey event

Definition at line 524 of file qwt_counter.cpp.

◆ maximum()

double QwtCounter::maximum ( ) const
Returns
The maximum of the range
See also
setRange(), setMaximum(), minimum()

Definition at line 306 of file qwt_counter.cpp.

◆ minimum()

double QwtCounter::minimum ( ) const
Returns
The minimum of the range
See also
setRange(), setMinimum(), maximum()

Definition at line 286 of file qwt_counter.cpp.

◆ numButtons()

int QwtCounter::numButtons ( ) const
Returns
The number of buttons on each side of the widget.
See also
setNumButtons()

Definition at line 388 of file qwt_counter.cpp.

◆ setIncSteps()

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
buttonButton index
numStepsNumber of steps
See also
incSteps()

Definition at line 403 of file qwt_counter.cpp.

◆ setMaximum()

void QwtCounter::setMaximum ( double  value)

Set the maximum value of the range

Parameters
valueMaximum value
See also
setRange(), setMinimum(), maximum()

Definition at line 297 of file qwt_counter.cpp.

◆ setMinimum()

void QwtCounter::setMinimum ( double  value)

Set the minimum value of the range

Parameters
valueMinimum value
See also
setRange(), setMaximum(), minimum()
Note
The maximum is adjusted if necessary to ensure that the range remains valid.

Definition at line 277 of file qwt_counter.cpp.

◆ setNumButtons()

void QwtCounter::setNumButtons ( int  numButtons)

Specify the number of buttons on each side of the label

Parameters
numButtonsNumber of buttons
See also
numButtons()

Definition at line 362 of file qwt_counter.cpp.

◆ setRange()

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
minMinimum value
maxMaximum value
See also
minimum(), maximum()

Definition at line 241 of file qwt_counter.cpp.

◆ setReadOnly()

void QwtCounter::setReadOnly ( bool  on)

Allow/disallow the user to manually edit the value.

Parameters
onTrue disable editing
See also
isReadOnly()

Definition at line 177 of file qwt_counter.cpp.

◆ setSingleStep()

void QwtCounter::setSingleStep ( double  stepSize)

Set the step size of the counter.

A value <= 0.0 disables stepping

Parameters
stepSizeSingle step size
See also
singleStep()

Definition at line 319 of file qwt_counter.cpp.

◆ setStepButton1()

void QwtCounter::setStepButton1 ( int  nSteps)

Set the number of increment steps for button 1

Parameters
nStepsNumber of steps

Definition at line 429 of file qwt_counter.cpp.

◆ setStepButton2()

void QwtCounter::setStepButton2 ( int  nSteps)

Set the number of increment steps for button 2

Parameters
nStepsNumber of steps

Definition at line 444 of file qwt_counter.cpp.

◆ setStepButton3()

void QwtCounter::setStepButton3 ( int  nSteps)

Set the number of increment steps for button 3

Parameters
nStepsNumber of steps

Definition at line 459 of file qwt_counter.cpp.

◆ setValid()

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
onIf true the counter will be set as valid
See also
setValue(), isValid()

Definition at line 142 of file qwt_counter.cpp.

◆ setValue

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
valueNew value
See also
isValid(), value(), valueChanged()
Warning
The value is clipped when it lies outside the range.

Definition at line 202 of file qwt_counter.cpp.

◆ setWrapping()

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
onEn/Disable wrapping
See also
wrapping()

Definition at line 342 of file qwt_counter.cpp.

◆ singleStep()

double QwtCounter::singleStep ( ) const
Returns
Single step size
See also
setSingleStep()

Definition at line 328 of file qwt_counter.cpp.

◆ value()

double QwtCounter::value ( ) const
Returns
Current value of the counter
See also
setValue(), valueChanged()

Definition at line 225 of file qwt_counter.cpp.

◆ valueChanged

void QwtCounter::valueChanged ( double  value)
signal

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

Parameters
valueThe new value

◆ wheelEvent()

void QwtCounter::wheelEvent ( QWheelEvent *  event)
overrideprotectedvirtual

Handle wheel events

Parameters
eventWheel event

Definition at line 591 of file qwt_counter.cpp.

◆ wrapping()

bool QwtCounter::wrapping ( ) const
Returns
True, when wrapping is set
See also
setWrapping()

Definition at line 351 of file qwt_counter.cpp.