qwt_counter.h

/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
 * Qwt Widget Library
 * Copyright (C) 1997   Josef Wilgen
 * Copyright (C) 2002   Uwe Rathmann
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the Qwt License, Version 1.0
 *****************************************************************************/

// vim: expandtab

#ifndef QWT_COUNTER_H
#define QWT_COUNTER_H

#include <qwidget.h>
#include "qwt_global.h"
#include "qwt_double_range.h"

/*!
  \brief 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:
\code
#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)));
\endcode
 */

class QWT_EXPORT QwtCounter : public QWidget, public QwtDoubleRange
{
    Q_OBJECT

    Q_PROPERTY( int numButtons READ numButtons WRITE setNumButtons )
    Q_PROPERTY( double basicstep READ step WRITE setStep )
    Q_PROPERTY( double minValue READ minVal WRITE setMinValue )
    Q_PROPERTY( double maxValue READ maxVal WRITE setMaxValue )
    Q_PROPERTY( int stepButton1 READ stepButton1 WRITE setStepButton1 )
    Q_PROPERTY( int stepButton2 READ stepButton2 WRITE setStepButton2 )
    Q_PROPERTY( int stepButton3 READ stepButton3 WRITE setStepButton3 )
    Q_PROPERTY( double value READ value WRITE setValue )
    Q_PROPERTY( bool editable READ editable WRITE setEditable )

public:
    /*!
        Button index
    */

    enum Button 
    {   
        Button1,    
        Button2,    
        Button3,    
        ButtonCnt   
    };

    explicit QwtCounter(QWidget *parent = NULL);
#if QT_VERSION < 0x040000
    explicit QwtCounter(QWidget *parent, const char *name);
#endif
    virtual ~QwtCounter();

    bool editable() const;
    void setEditable(bool);
 
    void setNumButtons(int n);
    int numButtons() const;
    
    void setIncSteps(QwtCounter::Button btn, int nSteps);
    int incSteps(QwtCounter::Button btn) const;

    virtual void setValue(double);
    virtual QSize sizeHint() const;

    virtual void polish();

    // a set of dummies to help the designer

    double step() const;
    void setStep(double s);
    double minVal() const;
    void setMinValue(double m);
    double maxVal() const;
    void setMaxValue(double m);
    void setStepButton1(int nSteps);
    int stepButton1() const;
    void setStepButton2(int nSteps);
    int stepButton2() const;
    void setStepButton3(int nSteps);
    int stepButton3() const;
    virtual double value() const;

signals:
    /*!
        This signal is emitted when a button has been released
        \param value The new value
    */
    void buttonReleased (double value);  

    /*!
        This signal is emitted when the counter's value has changed
        \param value The new value
    */
    void valueChanged (double value);

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

private slots:
    void btnReleased();
    void btnClicked();
    void textChanged();

private:
    void initCounter();
    void updateButtons();
    void showNum(double);
    virtual void valueChange();
    
    class PrivateData;
    PrivateData *d_data;
};

#endif