qwt_counter.h

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/* -*- 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_drange.h"

class QwtArrowButton;
class QLineEdit;

/*!
  \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 QwtDblRange
{
    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 )

public:
    /*!
        Button index
    */

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

    QwtCounter(QWidget *parent = 0, const char *name = 0);

    //! returns the step size
    double step() const {return QwtDblRange::step();}
    //! sets the step size
    void setStep(double s) {QwtDblRange::setStep(s);}
    //! returns the minimum value of the range
    double minVal() const {return minValue();}
    //! sets the minimum value of the range
    void setMinValue(double m) { setRange(m, maxValue(), step());}
    //! returns the maximum value of the range
    double maxVal() const {return QwtDblRange::maxValue();}
    //! sets the maximum value of the range
    void setMaxValue(double m) {setRange(minValue(), m, step());}
    //! set the number of increment steps for button 1
    void setStepButton1(int nSteps) {setIncSteps(Button1, nSteps);}
    //! returns the number of increment steps for button 1
    int stepButton1() const {return incSteps(Button1);}
    //! set the number of increment steps for button 2
    void setStepButton2(int nSteps) {setIncSteps(Button2, nSteps);}
    //! returns the number of increment steps for button 2
    int stepButton2() const {return incSteps(Button2);}
    //! set the number of increment steps for button 3
    void setStepButton3(int nSteps) {setIncSteps(Button3, nSteps);}
    //! returns the number of increment steps for button 3
    int stepButton3() const {return incSteps(Button3);}
    virtual double value() const { return QwtDblRange::value();}
 
    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 QSizePolicy sizePolicy() const;
    virtual QSize sizeHint() const;

    virtual bool eventFilter(QObject *, QEvent *);

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 void rangeChange();
    virtual void fontChange(const QFont &f);

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

private:
    void updateButtons();
    void showNum(double);
    virtual void valueChange();

    QwtArrowButton *d_buttonDown[ButtonCnt];
    QwtArrowButton *d_buttonUp[ButtonCnt];
    QLineEdit *d_valueEdit;

    int d_increment[ButtonCnt];
    int d_nButtons;

    bool d_blockKeys;
    bool d_keyPressed;
};

#endif