qlcdnumber.cpp

奇趣公司比较新的qt/emd版本

    q->setSizePolicy(QSizePolicy(QSizePolicy::Minimum, QSizePolicy::Minimum));
}

/*!
    Destroys the LCD number.
*/

QLCDNumber::~QLCDNumber()
{
}


/*!
    \property QLCDNumber::numDigits
    \brief the current number of digits displayed

    Corresponds to the current number of digits. If \l
    QLCDNumber::smallDecimalPoint is false, the decimal point occupies
    one digit position.

    \sa smallDecimalPoint
*/

void QLCDNumber::setNumDigits(int numDigits)
{
    Q_D(QLCDNumber);
    if (numDigits > 99) {
        qWarning("QLCDNumber::setNumDigits: (%s) Max 99 digits allowed",
                 objectName().toLocal8Bit().constData());
        numDigits = 99;
    }
    if (numDigits < 0) {
        qWarning("QLCDNumber::setNumDigits: (%s) Min 0 digits allowed",
                 objectName().toLocal8Bit().constData());
        numDigits = 0;
    }
    if (d->digitStr.isNull()) {                  // from constructor
        d->ndigits = numDigits;
        d->digitStr.fill(QLatin1Char(' '), d->ndigits);
        d->points.fill(0, d->ndigits);
        d->digitStr[d->ndigits - 1] = QLatin1Char('0');            // "0" is the default number
    } else {
        bool doDisplay = d->ndigits == 0;
        if (numDigits == d->ndigits)             // no change
            return;
        register int i;
        int dif;
        if (numDigits > d->ndigits) {            // expand
            dif = numDigits - d->ndigits;
            QString buf;
            buf.fill(QLatin1Char(' '), dif);
            d->digitStr.insert(0, buf);
            d->points.resize(numDigits);
            for (i=numDigits-1; i>=dif; i--)
                d->points.setBit(i, d->points.testBit(i-dif));
            for (i=0; i<dif; i++)
                d->points.clearBit(i);
        } else {                                        // shrink
            dif = d->ndigits - numDigits;
            d->digitStr = d->digitStr.right(numDigits);
            QBitArray tmpPoints = d->points;
            d->points.resize(numDigits);
            for (i=0; i<(int)numDigits; i++)
                d->points.setBit(i, tmpPoints.testBit(i+dif));
        }
        d->ndigits = numDigits;
        if (doDisplay)
            display(value());
        update();
    }
}

int QLCDNumber::numDigits() const
{
    Q_D(const QLCDNumber);
    return d->ndigits;
}

/*!
    \overload

    Returns true if \a num is too big to be displayed in its entirety;
    otherwise returns false.

    \sa display(), numDigits(), smallDecimalPoint()
*/

bool QLCDNumber::checkOverflow(int num) const
{
    Q_D(const QLCDNumber);
    bool of;
    int2string(num, d->base, d->ndigits, &of);
    return of;
}


/*!
    Returns true if \a num is too big to be displayed in its entirety;
    otherwise returns false.

    \sa display(), numDigits(), smallDecimalPoint()
*/

bool QLCDNumber::checkOverflow(double num) const
{
    Q_D(const QLCDNumber);
    bool of;
    double2string(num, d->base, d->ndigits, &of);
    return of;
}


/*!
    \property QLCDNumber::mode
    \brief the current display mode (number base)

    Corresponds to the current display mode, which is one of \c Bin,
    \c Oct, \c Dec (the default) and \c Hex. \c Dec mode can display
    floating point values, the other modes display the integer
    equivalent.

    \sa smallDecimalPoint(), setHexMode(), setDecMode(), setOctMode(), setBinMode()
*/

QLCDNumber::Mode QLCDNumber::mode() const
{
    Q_D(const QLCDNumber);
    return (QLCDNumber::Mode) d->base;
}

void QLCDNumber::setMode(Mode m)
{
    Q_D(QLCDNumber);
    d->base = m;
    display(d->val);
}


/*!
    \property QLCDNumber::value
    \brief the displayed value

    This property corresponds to the current value displayed by the
    LCDNumber.

    If the displayed value is not a number, the property has a value
    of 0.
*/

double QLCDNumber::value() const
{
    Q_D(const QLCDNumber);
    return d->val;
}

/*!
    \overload

    Displays the number \a num.
*/
void QLCDNumber::display(double num)
{
    Q_D(QLCDNumber);
    d->val = num;
    bool of;
    QString s = double2string(d->val, d->base, d->ndigits, &of);
    if (of)
        emit overflow();
    else
        d->internalSetString(s);
}

/*!
    \property QLCDNumber::intValue
    \brief the displayed value rounded to the nearest integer

    This property corresponds to the nearest integer to the current
    value displayed by the LCDNumber. This is the value used for
    hexadecimal, octal and binary modes.

    If the displayed value is not a number, the property has a value
    of 0.
*/
int QLCDNumber::intValue() const
{
    Q_D(const QLCDNumber);
    return qRound(d->val);
}


/*!
    \overload

    Displays the number \a num.
*/
void QLCDNumber::display(int num)
{
    Q_D(QLCDNumber);
    d->val = (double)num;
    bool of;
    QString s = int2string(num, d->base, d->ndigits, &of);
    if (of)
        emit overflow();
    else
        d->internalSetString(s);
}


/*!
    Displays the number represented by the string \a s.

    This version of the function disregards mode() and
    smallDecimalPoint().

    These digits and other symbols can be shown: 0/O, 1, 2, 3, 4, 5/S,
    6, 7, 8, 9/g, minus, decimal point, A, B, C, D, E, F, h, H, L, o,
    P, r, u, U, Y, colon, degree sign (which is specified as single
    quote in the string) and space. QLCDNumber substitutes spaces for
    illegal characters.
*/

void QLCDNumber::display(const QString &s)
{
    Q_D(QLCDNumber);
    d->val = 0;
    bool ok = false;
    double v = s.toDouble(&ok);
    if (ok)
        d->val = v;
    d->internalSetString(s);
}

/*!
    Calls setMode(Hex). Provided for convenience (e.g. for
    connecting buttons to it).

    \sa setMode(), setDecMode(), setOctMode(), setBinMode(), mode()
*/

void QLCDNumber::setHexMode()
{
    setMode(Hex);
}


/*!
    Calls setMode(Dec). Provided for convenience (e.g. for
    connecting buttons to it).

    \sa setMode(), setHexMode(), setOctMode(), setBinMode(), mode()
*/

void QLCDNumber::setDecMode()
{
    setMode(Dec);
}


/*!
    Calls setMode(Oct). Provided for convenience (e.g. for
    connecting buttons to it).

    \sa setMode(), setHexMode(), setDecMode(), setBinMode(), mode()
*/

void QLCDNumber::setOctMode()
{
    setMode(Oct);
}


/*!
    Calls setMode(Bin). Provided for convenience (e.g. for
    connecting buttons to it).

    \sa setMode(), setHexMode(), setDecMode(), setOctMode(), mode()
*/

void QLCDNumber::setBinMode()
{
    setMode(Bin);
}


/*!
    \property QLCDNumber::smallDecimalPoint
    \brief the style of the decimal point

    If true the decimal point is drawn between two digit positions.
    Otherwise it occupies a digit position of its own, i.e. is drawn
    in a digit position. The default is false.

    The inter-digit space is made slightly wider when the decimal
    point is drawn between the digits.

    \sa mode
*/

void QLCDNumber::setSmallDecimalPoint(bool b)
{
    Q_D(QLCDNumber);
    d->smallPoint = b;
    update();
}

bool QLCDNumber::smallDecimalPoint() const
{
    Q_D(const QLCDNumber);
    return d->smallPoint;
}



/*!\reimp
*/


void QLCDNumber::paintEvent(QPaintEvent *)
{
    Q_D(QLCDNumber);
    QPainter p(this);
    drawFrame(&p);
    if (d->smallPoint)
        d->drawString(d->digitStr, p, &d->points, false);
    else
        d->drawString(d->digitStr, p, 0, false);
}


void QLCDNumberPrivate::internalSetString(const QString& s)
{
    Q_Q(QLCDNumber);
    QString buffer;
    int i;
    int len = s.length();
    QBitArray newPoints(ndigits);

    if (!smallPoint) {
        if (len == ndigits)
            buffer = s;
        else
            buffer = s.right(ndigits).rightJustified(ndigits, QLatin1Char(' '));
    } else {
        int  index = -1;
        bool lastWasPoint = true;
        newPoints.clearBit(0);
        for (i=0; i<len; i++) {
            if (s[i] == QLatin1Char('.')) {
                if (lastWasPoint) {           // point already set for digit?
                    if (index == ndigits - 1) // no more digits
                        break;
                    index++;
                    buffer[index] = QLatin1Char(' ');        // 2 points in a row, add space
                }
                newPoints.setBit(index);        // set decimal point
                lastWasPoint = true;
            } else {
                if (index == ndigits - 1)
                    break;
                index++;
                buffer[index] = s[i];
                newPoints.clearBit(index);      // decimal point default off
                lastWasPoint = false;
            }
        }
        if (index < ((int) ndigits) - 1) {
            for(i=index; i>=0; i--) {
                buffer[ndigits - 1 - index + i] = buffer[i];
                newPoints.setBit(ndigits - 1 - index + i,
                                   newPoints.testBit(i));
            }
            for(i=0; i<ndigits-index-1; i++) {
                buffer[i] = QLatin1Char(' ');
                newPoints.clearBit(i);
            }
        }
    }

    if (buffer == digitStr)
        return;

    digitStr = buffer;
    if (smallPoint)
        points = newPoints;
    q->update();
}

/*!
  \internal
*/

void QLCDNumberPrivate::drawString(const QString &s, QPainter &p,
                                   QBitArray *newPoints, bool newString)
{
    Q_Q(QLCDNumber);
    QPoint  pos;

    int digitSpace = smallPoint ? 2 : 1;
    int xSegLen    = q->width()*5/(ndigits*(5 + digitSpace) + digitSpace);
    int ySegLen    = q->height()*5/12;
    int segLen     = ySegLen > xSegLen ? xSegLen : ySegLen;
    int xAdvance   = segLen*(5 + digitSpace)/5;
    int xOffset    = (q->width() - ndigits*xAdvance + segLen/5)/2;
    int yOffset    = (q->height() - segLen*2)/2;

    for (int i=0;  i<ndigits; i++) {
        pos = QPoint(xOffset + xAdvance*i, yOffset);
        if (newString)
            drawDigit(pos, p, segLen, s[i].toLatin1(), digitStr[i].toLatin1());
        else
            drawDigit(pos, p, segLen, s[i].toLatin1());
        if (newPoints) {
            char newPoint = newPoints->testBit(i) ? '.' : ' ';
            if (newString) {
                char oldPoint = points.testBit(i) ? '.' : ' ';
                drawDigit(pos, p, segLen, newPoint, oldPoint);
            } else {
                drawDigit(pos, p, segLen, newPoint);
            }
        }
    }
    if (newString) {
        digitStr = s;