qtextstream.cpp

QT 开发环境里面一个很重要的文件

/*!
    \overload

    Reads a character from the stream and stores it in \a c. The
    character from the stream is converted to ISO-5589-1 before it is
    stored.

    \sa QChar::toLatin1()
*/
QTextStream &QTextStream::operator>>(char &c)
{
    QChar ch;
    *this >> ch;
    c = ch.toLatin1();
    return *this;
}

/*!
    Reads an integer from the stream and stores it in \a i, then
    returns a reference to the QTextStream. The number is casted to
    the correct type before it is stored. If no number was detected on
    the stream, \a i is set to 0.

    By default, QTextStream will attempt to detect the base of the
    number using the following rules:

    \table
    \header \o Prefix                \o Base
    \row    \o "0b" or "0B"          \o 2 (binary)
    \row    \o "0" followed by "0-7" \o 8 (octal)
    \row    \o "0" otherwise         \o 10 (decimal)
    \row    \o "0x" or "0X"          \o 16 (hexadecimal)
    \row    \o "1" to "9"            \o 10 (decimal)
    \endtable

    By calling setIntegerBase(), you can specify the integer base
    explicitly. This will disable the auto-detection, and speed up
    QTextStream slightly.

    Leading whitespace is skipped.
*/
QTextStream &QTextStream::operator>>(signed short &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(signed short);
}

/*!
    \overload

    Stores the integer in the unsigned short \a i.
*/
QTextStream &QTextStream::operator>>(unsigned short &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(unsigned short);
}

/*!
    \overload

    Stores the integer in the signed int \a i.
*/
QTextStream &QTextStream::operator>>(signed int &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(signed int);
}

/*!
    \overload

    Stores the integer in the unsigned int \a i.
*/
QTextStream &QTextStream::operator>>(unsigned int &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(unsigned int);
}

/*!
    \overload

    Stores the integer in the signed long \a i.
*/
QTextStream &QTextStream::operator>>(signed long &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(signed long);
}

/*!
    \overload

    Stores the integer in the unsigned long \a i.
*/
QTextStream &QTextStream::operator>>(unsigned long &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(unsigned long);
}

/*!
    \overload

    Stores the integer in the qlonglong \a i.
*/
QTextStream &QTextStream::operator>>(qlonglong &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(qlonglong);
}

/*!
    \overload

    Stores the integer in the qulonglong \a i.
*/
QTextStream &QTextStream::operator>>(qulonglong &i)
{
    IMPLEMENT_STREAM_RIGHT_INT_OPERATOR(qulonglong);
}

/*!
    Reads a real number from the stream and stores it in \a f, then
    returns a reference to the QTextStream. The number is casted to
    the correct type. If no real number is detect on the stream, \a f
    is set to 0.0.

    Leading whitespace is skipped.
*/
QTextStream &QTextStream::operator>>(float &f)
{
    IMPLEMENT_STREAM_RIGHT_REAL_OPERATOR(float);
}

/*!
    \overload

    Stores the real number in the double \a f.
*/
QTextStream &QTextStream::operator>>(double &f)
{
    IMPLEMENT_STREAM_RIGHT_REAL_OPERATOR(double);
}

/*!
    Reads a word from the stream and stores it in \a str, then returns
    a reference to the stream. Words are separated by whitespace
    (i.e., all characters for which QChar::isSpace() returns true).

    Leading whitespace is skipped.
*/
QTextStream &QTextStream::operator>>(QString &str)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);

    str.clear();
    d->scan(0, 0, 0, QTextStreamPrivate::NotSpace);
    d->consumeLastToken();

    const QChar *ptr;
    int length;
    if (!d->scan(&ptr, &length, 0, QTextStreamPrivate::Space)) {
        setStatus(ReadPastEnd);
        return *this;
    }

    str = QString(ptr, length);
    d->consumeLastToken();
    return *this;
}

/*!
    \overload

    Converts the word to ISO-8859-1, then stores it in \a array.

    \sa QString::toLatin1()
*/
QTextStream &QTextStream::operator>>(QByteArray &array)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);

    array.clear();
    d->scan(0, 0, 0, QTextStreamPrivate::NotSpace);
    d->consumeLastToken();

    const QChar *ptr;
    int length;
    if (!d->scan(&ptr, &length, 0, QTextStreamPrivate::Space)) {
        setStatus(ReadPastEnd);
        return *this;
    }

    for (int i = 0; i < length; ++i)
        array += ptr[i].toLatin1();

    d->consumeLastToken();
    return *this;
}

/*!
    \overload

    Stores the word in \a c, terminated by a '\0' character. If no word is
    available, only the '\0' character is stored.

    Warning: Although convenient, this operator is dangerous and must
    be used with care. QTextStream assumes that \a c points to a
    buffer with enough space to hold the word. If the buffer is too
    small, your application may crash.

    If possible, use the QByteArray operator instead.
*/
QTextStream &QTextStream::operator>>(char *c)
{
    Q_D(QTextStream);
    *c = 0;
    CHECK_VALID_STREAM(*this);
    d->scan(0, 0, 0, QTextStreamPrivate::NotSpace);
    d->consumeLastToken();

    const QChar *ptr;
    int length;
    if (!d->scan(&ptr, &length, 0, QTextStreamPrivate::Space)) {
        setStatus(ReadPastEnd);
        return *this;
    }

    for (int i = 0; i < length; ++i)
        *c++ = ptr[i].toLatin1();
    *c = '\0';
    d->consumeLastToken();
    return *this;
}

/*! \internal
 */
bool QTextStreamPrivate::putNumber(qulonglong number, bool negative)
{
    QString tmp;
    if (negative)
        tmp = QLatin1Char('-');
    else if (numberFlags & QTextStream::ForceSign)
        tmp = QLatin1Char('+');

    if (numberFlags & QTextStream::ShowBase) {
        switch (integerBase) {
        case 2: tmp += QLatin1String("0b"); break;
        case 8: tmp += QLatin1String("0"); break;
        case 16: tmp += QLatin1String("0x"); break;
        default: break;
        }
    }

    tmp += QString::number(number, integerBase ? integerBase : 10);
    if (numberFlags & QTextStream::UppercaseBase)
        tmp = tmp.toUpper(); // ### in-place instead

    return putString(tmp);
}

/*!
    \internal
    \overload
*/
QTextStream &QTextStream::operator<<(QBool b)
{
    return *this << bool(b);
}

/*!
    Writes the character \a c to the stream, then returns a reference
    to the QTextStream.

    \sa setFieldWidth()
*/
QTextStream &QTextStream::operator<<(QChar c)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);
    d->putString(QString(c));
    return *this;
}

/*!
    \overload

    Converts \a c from ASCII to a QChar, then writes it to the stream.
*/
QTextStream &QTextStream::operator<<(char c)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);
    d->putString(QString(QChar::fromAscii(c)));
    return *this;
}

/*!
    Writes the integer number \a i to the stream, then returns a
    reference to the QTextStream. By default, the number is stored in
    decimal form, but you can also set the base by calling
    setIntegerBase().

    \sa setFieldWidth(), setNumberFlags()
*/
QTextStream &QTextStream::operator<<(signed short i)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);
    d->putNumber((qulonglong)qAbs(qlonglong(i)), i < 0);
    return *this;
}

/*!
    \overload

    Writes the unsigned short \a i to the stream.
*/
QTextStream &QTextStream::operator<<(unsigned short i)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);
    d->putNumber((qulonglong)i, false);
    return *this;
}

/*!
    \overload

    Writes the signed int \a i to the stream.
*/
QTextStream &QTextStream::operator<<(signed int i)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);
    d->putNumber((qulonglong)qAbs(qlonglong(i)), i < 0);
    return *this;
}

/*!
    \overload

    Writes the unsigned int \a i to the stream.
*/
QTextStream &QTextStream::operator<<(unsigned int i)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);
    d->putNumber((qulonglong)i, false);
    return *this;
}

/*!
    \overload

    Writes the signed long \a i to the stream.
*/
QTextStream &QTextStream::operator<<(signed long i)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);
    d->putNumber((qulonglong)qAbs(qlonglong(i)), i < 0);
    return *this;
}

/*!
    \overload

    Writes the unsigned long \a i to the stream.
*/
QTextStream &QTextStream::operator<<(unsigned long i)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);
    d->putNumber((qulonglong)i, false);
    return *this;
}

/*!
    \overload

    Writes the qlonglong \a i to the stream.
*/
QTextStream &QTextStream::operator<<(qlonglong i)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);
    d->putNumber((qulonglong)qAbs(i), i < 0);
    return *this;
}

/*!
    \overload

    Writes the qulonglong \a i to the stream.
*/
QTextStream &QTextStream::operator<<(qulonglong i)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);
    d->putNumber(i, false);
    return *this;
}

/*!
    Writes the real number \a f to the stream, then returns a
    reference to the QTextStream. By default, QTextStream stores it
    using SmartNotation, with up to 6 digits of precision. You can
    change the textual representation QTextStream will use for real
    numbers by calling setRealNumberNotation(),
    setRealNumberPrecision() and setNumberFlags().

    \sa setFieldWidth(), setRealNumberNotation(),
    setRealNumberPrecision(), setNumberFlags()
*/
QTextStream &QTextStream::operator<<(float f)
{
    return *this << double(f);
}

/*!
    \overload

    Writes the double \a f to the stream.
*/
QTextStream &QTextStream::operator<<(double f)
{
    Q_D(QTextStream);
    CHECK_VALID_STREAM(*this);

    char f_char;
    char format[16];
    if (d->realNumberNotation == FixedNotation)
        f_char = 'f';
    else if (d->realNumberNotation == ScientificNotation)
        f_char = (d->numberFlags & UppercaseBase) ? 'E' : 'e';
    else
        f_char = (d->numberFlags & UppercaseBase) ? 'G' : 'g';

    // generate format string
    register char *fs = format;

    // "%.<prec>l<f_char>"
    *fs++ = '%';
    if (d->numberFlags & QTextStream::ForcePoint)
        *fs++ = '#';
    *fs++ = '.';
    int prec = d->realNumberPrecision;
    if (prec > 99)
        prec = 99;
    if (prec >= 10) {
        *fs++ = prec / 10 + '0';
        *fs++ = prec % 10 + '0';
    } else {
        *fs++ = prec + '0';
    }
    *fs++ = 'l';
    *fs++ = f_char;
    *fs = '\0';
    QString num;
    num.sprintf(format, f);                        // convert to text

    if (f > 0.0 && (d->numberFlags & ForceSign))
        num.prepend(QLatin1Char('+'));

    d->putString(num);
    return *this;
}

/*!
    Writes the string \a string to the stream, and returns a reference
    to the QTextStream. The string is first encoded using the assigned