qdatetime.cpp

奇趣公司比较新的qt/emd版本

    \i 1 = "Jan"
    \i 2 = "Feb"
    \i 3 = "Mar"
    \i 4 = "Apr"
    \i 5 = "May"
    \i 6 = "Jun"
    \i 7 = "Jul"
    \i 8 = "Aug"
    \i 9 = "Sep"
    \i 10 = "Oct"
    \i 11 = "Nov"
    \i 12 = "Dec"
    \endlist

    The month names will be localized according to the system's locale
    settings.

    \sa toString(), longMonthName(), shortDayName(), longDayName()
*/

QString QDate::shortMonthName(int month)
{
    if (month < 1 || month > 12) {
        qWarning("QDate::shortMonthName: Parameter out ouf range");
        month = 1;
    }
    return QLocale::system().monthName(month, QLocale::ShortFormat);
}

/*!
    Returns the long name of the \a month using the following
    convention:

    \list
    \i 1 = "January"
    \i 2 = "February"
    \i 3 = "March"
    \i 4 = "April"
    \i 5 = "May"
    \i 6 = "June"
    \i 7 = "July"
    \i 8 = "August"
    \i 9 = "September"
    \i 10 = "October"
    \i 11 = "November"
    \i 12 = "December"
    \endlist

    The month names will be localized according to the system's locale
    settings.

    \sa toString(), shortMonthName(), shortDayName(), longDayName()
*/

QString QDate::longMonthName(int month)
{
    if (month < 1 || month > 12) {
        qWarning("QDate::longMonthName: Parameter out ouf range");
        month = 1;
    }
    return QLocale::system().monthName(month, QLocale::LongFormat);
}

/*!
    Returns the name of the \a weekday using the following
    convention:

    \list
    \i 1 = "Mon"
    \i 2 = "Tue"
    \i 3 = "Wed"
    \i 4 = "Thu"
    \i 5 = "Fri"
    \i 6 = "Sat"
    \i 7 = "Sun"
    \endlist

    The day names will be localized according to the system's locale
    settings.

    \sa toString(), shortMonthName(), longMonthName(), longDayName()
*/

QString QDate::shortDayName(int weekday)
{
    if (weekday < 1 || weekday > 7) {
        qWarning("QDate::shortDayName: Parameter out of range");
        weekday = 1;
    }
    return QLocale::system().dayName(weekday, QLocale::ShortFormat);
}

/*!
    Returns the long name of the \a weekday using the following
    convention:

    \list
    \i 1 = "Monday"
    \i 2 = "Tuesday"
    \i 3 = "Wednesday"
    \i 4 = "Thursday"
    \i 5 = "Friday"
    \i 6 = "Saturday"
    \i 7 = "Sunday"
    \endlist

    The day names will be localized according to the system's locale
    settings.

    \sa toString(), shortDayName(), shortMonthName(), longMonthName()
*/

QString QDate::longDayName(int weekday)
{
    if (weekday < 1 || weekday > 7) {
        qWarning("QDate::longDayName: Parameter out of range");
        weekday = 1;
    }
    return QLocale::system().dayName(weekday, QLocale::LongFormat);
}
#endif //QT_NO_TEXTDATE

#ifndef QT_NO_DATESTRING

/*!
    \fn QString QDate::toString(Qt::DateFormat format) const

    \overload

    Returns the date as a string. The \a format parameter determines
    the format of the string.

    If the \a format is Qt::TextDate, the string is formatted in
    the default way. QDate::shortDayName() and QDate::shortMonthName()
    are used to generate the string, so the day and month names will
    be localized names. An example of this formatting is
    "Sat May 20 1995".

    If the \a format is Qt::ISODate, the string format corresponds
    to the ISO 8601 extended specification for representations of
    dates and times, taking the form YYYY-MM-DD, where YYYY is the
    year, MM is the month of the year (between 01 and 12), and DD is
    the day of the month between 01 and 31.

    If the \a format is Qt::LocalDate or Qt::SystemLocaleDate, the string
    format depends on the locale settings of the system. Identical to
    calling QLocale::system().toString(date, QLocale::ShortFormat).
    \e{Qt::LocalDate has been deprecated, please use Qt::SystemLocaleDate
    instead.}

    If the \a format is Qt::LocaleDate, the string
    format depends on the default application locale. This is the
    locale set with QLocale::setDefault(), or the system locale if no
    default locale has been set. Identical to calling
    QLocale().toString(date, QLocale::ShortFormat);

    If the datetime is invalid, an empty string will be returned.

    \warning The Qt::ISODate format is only valid for years in the
    range 0 to 9999. This restriction may apply to Qt::LocalDate as
    well, depending on the locale settings.

    \sa shortDayName(), shortMonthName()
*/
QString QDate::toString(Qt::DateFormat f) const
{
    if (!isValid())
        return QString();
    int y, m, d;
    getDateFromJulianDay(jd, &y, &m, &d);
    switch (f) {
    case Qt::SystemLocaleDate:
        return QLocale::system().toString(*this, QLocale::ShortFormat);
    case Qt::LocaleDate:
        return QLocale().toString(*this, QLocale::ShortFormat);
    default:
#ifndef QT_NO_TEXTDATE
    case Qt::TextDate:
        {
            return QString::fromLatin1("%0 %1 %2 %3")
                .arg(shortDayName(dayOfWeek()))
                .arg(shortMonthName(m))
                .arg(d)
                .arg(y);
        }
#endif
    case Qt::ISODate:
        {
            if (year() < 0 || year() > 9999)
                return QString();
            QString month(QString::number(m).rightJustified(2, QLatin1Char('0')));
            QString day(QString::number(d).rightJustified(2, QLatin1Char('0')));
            return QString::number(y) + QLatin1Char('-') + month + QLatin1Char('-') + day;
        }
    }
}

/*!
    Returns the date as a string. The \a format parameter determines
    the format of the result string.

    These expressions may be used:

    \table
    \header \i Expression \i Output
    \row \i d \i the day as number without a leading zero (1 to31)
    \row \i dd \i the day as number with a leading zero (01 to 31)
    \row \i ddd
         \i the abbreviated localized day name (e.g. 'Mon' to 'Sun').
            Uses QDate::shortDayName().
    \row \i dddd
         \i the long localized day name (e.g. 'Qt::Monday' to 'Qt::Sunday').
            Uses QDate::longDayName().
    \row \i M \i the month as number without a leading zero (1-12)
    \row \i MM \i the month as number with a leading zero (01-12)
    \row \i MMM
         \i the abbreviated localized month name (e.g. 'Jan' to 'Dec').
            Uses QDate::shortMonthName().
    \row \i MMMM
         \i the long localized month name (e.g. 'January' to 'December').
            Uses QDate::longMonthName().
    \row \i yy \i the year as two digit number (00 to 99)
    \row \i yyyy \i the year as four digit number
    \endtable

    All other input characters will be ignored. Any sequence of characters that
    are enclosed in singlequotes will be treated as text and not be used as an
    expression. Two consecutive singlequotes ("''") are replaced by a singlequote
    in the output.

    Example format strings (assuming that the QDate is the 20 July
    1969):

    \table
    \header \o Format            \o Result
    \row    \o dd.MM.yyyy        \o 20.07.1969
    \row    \o ddd MMMM d yy     \o Sun July 20 69
    \row    \o 'The day is' dddd \o The day is Sunday
    \endtable

    If the datetime is invalid, an empty string will be returned.

    \warning This function is only valid for years in the range 0 to
    9999.

    \sa QDateTime::toString() QTime::toString()

*/
QString QDate::toString(const QString& format) const
{
    if (uint(year()) > 9999)
        return QString();
    return fmtDateTime(format, 0, this);
}
#endif //QT_NO_DATESTRING

/*!
    \obsolete

    Sets the date's year \a y, month \a m, and day \a d.

    If \a y is in the range 0 to 99, it is interpreted as 1900 to
    1999.

    Use setDate() instead.
*/

bool QDate::setYMD(int y, int m, int d)
{
    if (uint(y) <= 99)
        y += 1900;
    return setDate(y, m, d);
}

/*!
    \since 4.2

    Sets the date's \a year, \a month, and \a day. Returns true if
    the date is valid; otherwise returns false.

    If the specified date is invalid, the QDate object is set to be
    invalid. Any date before 2 January 4713 B.C. is considered
    invalid.

    \sa isValid()
*/
bool QDate::setDate(int year, int month, int day)
{
    if (!isValid(year, month, day)) {
        jd = 0;
    } else {
        jd = julianDayFromDate(year, month, day);
    }
    return jd != 0;
}

/*!
    Returns a QDate object containing a date \a ndays later than the
    date of this object (or earlier if \a ndays is negative).

    \sa addMonths() addYears() daysTo()
*/

QDate QDate::addDays(int ndays) const
{
    QDate d;
    d.jd = jd + ndays;
    return d;
}

/*!
    Returns a QDate object containing a date \a nmonths later than the
    date of this object (or earlier if \a nmonths is negative).

    \sa addDays() addYears()
*/

QDate QDate::addMonths(int nmonths) const
{
    int y, m, d;
    getDateFromJulianDay(jd, &y, &m, &d);

    while (nmonths != 0) {
        if (nmonths < 0 && nmonths + 12 <= 0) {
            y--;
            nmonths+=12;
        } else if (nmonths < 0) {
            m+= nmonths;
            nmonths = 0;
            if (m <= 0) {
                --y;
                m += 12;
            }
        } else if (nmonths - 12 >= 0) {
            y++;
            nmonths -= 12;
        } else if (m == 12) {
            y++;
            m = 0;
        } else {
            m += nmonths;
            nmonths = 0;
            if (m > 12) {
                ++y;
                m -= 12;
            }
        }
    }

    return fixedDate(y, m, d);
}

/*!
    Returns a QDate object containing a date \a nyears later than the
    date of this object (or earlier if \a nyears is negative).

    \sa addDays(), addMonths()
*/

QDate QDate::addYears(int nyears) const
{
    int y, m, d;
    getDateFromJulianDay(jd, &y, &m, &d);
    y += nyears;
    return fixedDate(y, m, d);
}

/*!
    Returns the number of days from this date to \a d (which is
    negative if \a d is earlier than this date).

    Example:
    \code
        QDate d1(1995, 5, 17);  // May 17, 1995
        QDate d2(1995, 5, 20);  // May 20, 1995
        d1.daysTo(d2);          // returns 3
        d2.daysTo(d1);          // returns -3
    \endcode

    \sa addDays()
*/

int QDate::daysTo(const QDate &d) const
{
    return d.jd - jd;
}


/*!
    \fn bool QDate::operator==(const QDate &d) const

    Returns true if this date is equal to \a d; otherwise returns
    false.
*/

/*!
    \fn bool QDate::operator!=(const QDate &d) const

    Returns true if this date is different from \a d; otherwise
    returns false.
*/

/*!
    \fn bool QDate::operator<(const QDate &d) const

    Returns true if this date is earlier than \a d; otherwise returns
    false.
*/

/*!
    \fn bool QDate::operator<=(const QDate &d) const

    Returns true if this date is earlier than or equal to \a d;
    otherwise returns false.
*/

/*!
    \fn bool QDate::operator>(const QDate &d) const

    Returns true if this date is later than \a d; otherwise returns
    false.
*/

/*!
    \fn bool QDate::operator>=(const QDate &d) const

    Returns true if this date is later than or equal to \a d;
    otherwise returns false.
*/

/*!
    \overload
    Returns the current date, as reported by the system clock.

    \sa QTime::currentTime(), QDateTime::currentDateTime()
*/

QDate QDate::currentDate()
{
    QDate d;
#if defined(Q_OS_WIN)
    SYSTEMTIME st;
    memset(&st, 0, sizeof(SYSTEMTIME));
    GetLocalTime(&st);
    d.jd = julianDayFromDate(st.wYear, st.wMonth, st.wDay);
#else
    // posix compliant system
    time_t ltime;
    time(&ltime);
    tm *t;

#if !defined(QT_NO_THREAD) && defined(_POSIX_THREAD_SAFE_FUNCTIONS)
    // use the reentrant version of localtime() where available
    tm res;
    t = localtime_r(&ltime, &res);
#else
    t = localtime(&ltime);
#endif // !QT_NO_THREAD && _POSIX_THREAD_SAFE_FUNCTIONS

    d.jd = julianDayFromDate(t->tm_year + 1900, t->tm_mon + 1, t->tm_mday);
#endif
    return d;