qwt_counter.cpp

/* -*- 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

#include <qlayout.h>
#include <qlineedit.h>
#include <qvalidator.h>
#include <qevent.h>
#include <qstyle.h>
#include "qwt_math.h"
#include "qwt_counter.h"
#include "qwt_arrow_button.h"

class QwtCounter::PrivateData
{
public:
    PrivateData():
        editable(true)
    {
        increment[Button1] = 1;
        increment[Button2] = 10;
        increment[Button3] = 100;
    }

    QwtArrowButton *buttonDown[ButtonCnt];
    QwtArrowButton *buttonUp[ButtonCnt];
    QLineEdit *valueEdit;

    int increment[ButtonCnt];
    int nButtons;

    bool editable;
};

/*!
  The default number of buttons is set to 2. The default increments are:
  \li Button 1: 1 step
  \li Button 2: 10 steps
  \li Button 3: 100 steps

  \param parent
 */
QwtCounter::QwtCounter(QWidget *parent):
    QWidget(parent) 
{
    initCounter();
}

#if QT_VERSION < 0x040000
/*!
  The default number of buttons is set to 2. The default increments are:
  \li Button 1: 1 step
  \li Button 2: 10 steps
  \li Button 3: 100 steps

  \param parent
 */
QwtCounter::QwtCounter(QWidget *parent, const char *name):
    QWidget(parent, name) 
{
    initCounter();
}
#endif

void QwtCounter::initCounter()
{
    d_data = new PrivateData;

#if QT_VERSION >= 0x040000
    using namespace Qt;
#endif

    QHBoxLayout *layout = new QHBoxLayout(this);
    layout->setSpacing(0);
    layout->setMargin(0);

    int i;
    for(i = ButtonCnt - 1; i >= 0; i--)
    {
        QwtArrowButton *btn =
            new QwtArrowButton(i+1, Qt::DownArrow,this);
        btn->setFocusPolicy(NoFocus);
        btn->installEventFilter(this);
        layout->addWidget(btn);

        connect(btn, SIGNAL(released()), SLOT(btnReleased()));
        connect(btn, SIGNAL(clicked()), SLOT(btnClicked()));

        d_data->buttonDown[i] = btn;
    }

    d_data->valueEdit = new QLineEdit(this);
    d_data->valueEdit->setReadOnly(false);
    d_data->valueEdit->setValidator(new QDoubleValidator(d_data->valueEdit));
    layout->addWidget(d_data->valueEdit);

#if QT_VERSION >= 0x040000
    connect( d_data->valueEdit, SIGNAL(editingFinished()), 
        SLOT(textChanged()) );
#else
    connect( d_data->valueEdit, SIGNAL(returnPressed()), SLOT(textChanged()) );
    connect( d_data->valueEdit, SIGNAL(lostFocus()), SLOT(textChanged()) );
#endif

    layout->setStretchFactor(d_data->valueEdit, 10);

    for(i = 0; i < ButtonCnt; i++)
    {
#if QT_VERSION >= 0x040000
        using namespace Qt;
#endif
        QwtArrowButton *btn =
            new QwtArrowButton(i+1, Qt::UpArrow, this);
        btn->setFocusPolicy(NoFocus);
        btn->installEventFilter(this);
        layout->addWidget(btn);

        connect(btn, SIGNAL(released()), SLOT(btnReleased()));
        connect(btn, SIGNAL(clicked()), SLOT(btnClicked()));
    
        d_data->buttonUp[i] = btn;
    }

    setNumButtons(2);
    setRange(0.0,1.0,0.001);
    setValue(0.0);

    setSizePolicy(
        QSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed));

    setFocusProxy(d_data->valueEdit);
    setFocusPolicy(StrongFocus);
}

//! Destructor
QwtCounter::~QwtCounter()
{
    delete d_data;
}

/*!
  Sets the minimum width for the buttons
*/
void QwtCounter::polish()
{
    const int w = d_data->valueEdit->fontMetrics().width("W") + 8;

    for ( int i = 0; i < ButtonCnt; i++ )
    {
        d_data->buttonDown[i]->setMinimumWidth(w);
        d_data->buttonUp[i]->setMinimumWidth(w);
    }

#if QT_VERSION < 0x040000
    QWidget::polish();
#endif
}

//! Set from lineedit
void QwtCounter::textChanged() 
{
    if ( !d_data->editable ) 
        return;

    bool converted = false;

    const double value = d_data->valueEdit->text().toDouble(&converted);
    if ( converted ) 
       setValue( value );
}

/**
  \brief Allow/disallow the user to manually edit the value

  \param editable true enables editing
  \sa editable()
*/
void QwtCounter::setEditable(bool editable)
{
#if QT_VERSION >= 0x040000
    using namespace Qt;
#endif
    if ( editable == d_data->editable ) 
        return;

    d_data->editable = editable;
    d_data->valueEdit->setReadOnly(!editable);
}

//! returns whether the line edit is edatble. (default is yes)
bool QwtCounter::editable() const 
{   
    return d_data->editable;
}

/*!
   Handle PolishRequest events 
*/
bool QwtCounter::event ( QEvent * e ) 
{
#if QT_VERSION >= 0x040000
    if ( e->type() == QEvent::PolishRequest )
        polish();
#endif
    return QWidget::event(e);
}

/*!
  Handles 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)
*/

void QwtCounter::keyPressEvent (QKeyEvent *e)
{
    bool accepted = true;

    switch ( e->key() )
    {
        case Qt::Key_Home:
#if QT_VERSION >= 0x040000
            if ( e->modifiers() & Qt::ControlModifier )
#else
            if ( e->state() & Qt::ControlButton )
#endif
                setValue(minValue());
            else
                accepted = false;
            break;
        case Qt::Key_End:
#if QT_VERSION >= 0x040000
            if ( e->modifiers() & Qt::ControlModifier )
#else
            if ( e->state() & Qt::ControlButton )
#endif
                setValue(maxValue());
            else
                accepted = false;
            break;
        case Qt::Key_Up:
            incValue(d_data->increment[0]);
            break;
        case Qt::Key_Down:
            incValue(-d_data->increment[0]);
            break;
        case Qt::Key_PageUp:
        case Qt::Key_PageDown:
        {
            int increment = d_data->increment[0];
            if ( d_data->nButtons >= 2 )
                increment = d_data->increment[1];
            if ( d_data->nButtons >= 3 )
            {
#if QT_VERSION >= 0x040000
                if ( e->modifiers() & Qt::ShiftModifier )
#else
                if ( e->state() & Qt::ShiftButton )
#endif
                    increment = d_data->increment[2];
            }
            if ( e->key() == Qt::Key_PageDown )
                increment = -increment;
            incValue(increment);
            break;
        }
        default:
            accepted = false;
    }

    if ( accepted )
    {
        e->accept();
        return;
    }

    QWidget::keyPressEvent (e);
}

void QwtCounter::wheelEvent(QWheelEvent *e)
{
    e->accept();

    if ( d_data->nButtons <= 0 )
        return;

    int increment = d_data->increment[0];
    if ( d_data->nButtons >= 2 )
    {
#if QT_VERSION >= 0x040000
        if ( e->modifiers() & Qt::ControlModifier )
#else
        if ( e->state() & Qt::ControlButton )
#endif
            increment = d_data->increment[1];
    }
    if ( d_data->nButtons >= 3 )
    {
#if QT_VERSION >= 0x040000
        if ( e->modifiers() & Qt::ShiftModifier )
#else
        if ( e->state() & Qt::ShiftButton )
#endif
            increment = d_data->increment[2];
    }
        
    for ( int i = 0; i < d_data->nButtons; i++ )
    {
        if ( d_data->buttonDown[i]->geometry().contains(e->pos()) ||
            d_data->buttonUp[i]->geometry().contains(e->pos()) )
        {
            increment = d_data->increment[i];
        }
    }

    const int wheel_delta = 120;

    int delta = e->delta();
    if ( delta >= 2 * wheel_delta )
        delta /= 2; // Never saw an abs(delta) < 240

    incValue(delta / wheel_delta * increment);
}

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

  \param btn One of \c QwtCounter::Button1, \c QwtCounter::Button2,
             \c QwtCounter::Button3
  \param nSteps Number of steps
*/
void QwtCounter::setIncSteps(QwtCounter::Button btn, int nSteps)
{
    if (( btn >= 0) && (btn < ButtonCnt))
       d_data->increment[btn] = nSteps;
}

/*!
  \return the number of steps by which a specified button increments the value
  or 0 if the button is invalid.
  \param btn One of \c QwtCounter::Button1, \c QwtCounter::Button2,
  \c QwtCounter::Button3
*/
int QwtCounter::incSteps(QwtCounter::Button btn) const
{
    if (( btn >= 0) && (btn < ButtonCnt))
       return d_data->increment[btn];

    return 0;
}

/*!
  \brief Set a new value
  \param v new value
  Calls QwtDoubleRange::setValue and does all visual updates.
  \sa QwtDoubleRange::setValue
*/

void QwtCounter::setValue(double v)
{
    QwtDoubleRange::setValue(v);

    showNum(value());
    updateButtons();
}

/*!
  \brief Notify a change of value
*/
void QwtCounter::valueChange()
{
    if ( isValid() )
        showNum(value());
    else
        d_data->valueEdit->setText(QString::null);

    updateButtons();

    if ( isValid() )
        emit valueChanged(value());
}

/*!
  \brief Update buttons according to the current value

  When the QwtCounter under- or over-flows, the focus is set to the smallest
  up- or down-button and counting is disabled.

  Counting is re-enabled on a button release event (mouse or space bar).
*/
void QwtCounter::updateButtons()
{
    if ( isValid() )
    {
        // 1. save enabled state of the smallest down- and up-button
        // 2. change enabled state on under- or over-flow

        for ( int i = 0; i < ButtonCnt; i++ )
        {
            d_data->buttonDown[i]->setEnabled(value() > minValue());
            d_data->buttonUp[i]->setEnabled(value() < maxValue());
        }
    }
    else
    {
        for ( int i = 0; i < ButtonCnt; i++ )
        {
            d_data->buttonDown[i]->setEnabled(false);
            d_data->buttonUp[i]->setEnabled(false);
        }
    }
}

/*!
  \brief Specify the number of buttons on each side of the label
  \param n Number of buttons
*/
void QwtCounter::setNumButtons(int n)
{
    if ( n<0 || n>ButtonCnt )
        return;

    for ( int i = 0; i < ButtonCnt; i++ )
    {
        if ( i < n )
        {
            d_data->buttonDown[i]->show();
            d_data->buttonUp[i]->show();
        }
        else
        {
            d_data->buttonDown[i]->hide();
            d_data->buttonUp[i]->hide();
        }
    }

    d_data->nButtons = n;
}

/*!
    \return The number of buttons on each side of the widget.
*/
int QwtCounter::numButtons() const 
{ 
    return d_data->nButtons; 
}

//!  Display number string
void QwtCounter::showNum(double d)
{
    QString v;
    v.setNum(d);

    const int cursorPos = d_data->valueEdit->cursorPosition();
    d_data->valueEdit->setText(v);
    d_data->valueEdit->setCursorPosition(cursorPos);
}

//!  Button clicked
void QwtCounter::btnClicked()
{
    for ( int i = 0; i < ButtonCnt; i++ )
    {
        if ( d_data->buttonUp[i] == sender() )
            incValue(d_data->increment[i]);

        if ( d_data->buttonDown[i] == sender() )
            incValue(-d_data->increment[i]);
    }
}

//!  Button released
void QwtCounter::btnReleased()
{
    emit buttonReleased(value());
}

/*!
  \brief Notify change of range

  This function updates the enabled property of
  all buttons contained in QwtCounter.
*/
void QwtCounter::rangeChange()
{
    updateButtons();
}

//! A size hint
QSize QwtCounter::sizeHint() const
{
    QString tmp;

    int w = tmp.setNum(minValue()).length();
    int w1 = tmp.setNum(maxValue()).length();
    if ( w1 > w )
        w = w1;
    w1 = tmp.setNum(minValue() + step()).length();
    if ( w1 > w )
        w = w1;
    w1 = tmp.setNum(maxValue() - step()).length();
    if ( w1 > w )
        w = w1;

    tmp.fill('9', w);

    QFontMetrics fm(d_data->valueEdit->font());
    w = fm.width(tmp) + 2;
#if QT_VERSION >= 0x040000
    if ( d_data->valueEdit->hasFrame() )
        w += 2 * style()->pixelMetric(QStyle::PM_DefaultFrameWidth);
#else
    w += 2 * d_data->valueEdit->frameWidth(); 
#endif

    // Now we replace default sizeHint contribution of d_data->valueEdit by
    // what we really need.

    w += QWidget::sizeHint().width() - d_data->valueEdit->sizeHint().width();

    const int h = qwtMin(QWidget::sizeHint().height(), 
        d_data->valueEdit->minimumSizeHint().height());
    return QSize(w, h);
}

//! returns the step size
double QwtCounter::step() const
{
    return QwtDoubleRange::step();
}
    
//! sets the step size
void QwtCounter::setStep(double s)
{
    QwtDoubleRange::setStep(s);
}

//! returns the minimum value of the range
double QwtCounter::minVal() const
{
    return minValue();
}

//! sets the minimum value of the range
void QwtCounter::setMinValue(double m)
{
    setRange(m, maxValue(), step());
}

//! returns the maximum value of the range
double QwtCounter::maxVal() const
{
    return QwtDoubleRange::maxValue();
}

//! sets the maximum value of the range
void QwtCounter::setMaxValue(double m)
{
    setRange(minValue(), m, step());
}

//! set the number of increment steps for button 1
void QwtCounter::setStepButton1(int nSteps)
{
    setIncSteps(Button1, nSteps);
}

//! returns the number of increment steps for button 1
int QwtCounter::stepButton1() const
{
    return incSteps(Button1);
}

//! set the number of increment steps for button 2
void QwtCounter::setStepButton2(int nSteps)
{
    setIncSteps(Button2, nSteps);
}

//! returns the number of increment steps for button 2
int QwtCounter::stepButton2() const
{
    return incSteps(Button2);
}

//! set the number of increment steps for button 3
void QwtCounter::setStepButton3(int nSteps)
{
    setIncSteps(Button3, nSteps);
}

//! returns the number of increment steps for button 3
int QwtCounter::stepButton3() const
{
    return incSteps(Button3);
}

double QwtCounter::value() const
{
    return QwtDoubleRange::value();
}