qdatetime.cpp

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

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**
** This file is part of the Qtopia Environment.
** 
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** under the terms of the GNU General Public License as published by the
** Free Software Foundation; either version 2 of the License, or (at your
** option) any later version.
** 
** A copy of the GNU GPL license version 2 is included in this package as 
** LICENSE.GPL.
**
** This program is distributed in the hope that it will be useful, but
** WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 
** See the GNU General Public License for more details.
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** the code of this program with Qtopia applications copyrighted, developed
** and distributed by Trolltech under the terms of the Qtopia Personal Use
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** in all respects for all of the code used other than the applications
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#include "qplatformdefs.h"

#include "qdatetime.h"
#include "qdatastream.h"
#include "qregexp.h"

#include <stdio.h>
#ifndef Q_OS_TEMP
#include <time.h>
#endif

#if defined(Q_OS_WIN32)
#include <windows.h>
#endif

static const uint FIRST_DAY	= 2361222;	// Julian day for 1752-09-14
static const int  FIRST_YEAR	= 1752;		// ### wrong for many countries
static const uint SECS_PER_DAY	= 86400;
static const uint MSECS_PER_DAY = 86400000;
static const uint SECS_PER_HOUR = 3600;
static const uint MSECS_PER_HOUR= 3600000;
static const uint SECS_PER_MIN	= 60;
static const uint MSECS_PER_MIN = 60000;

static const short monthDays[] = {
    0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

static const char * const qt_shortMonthNames[] = {
	"Jan", "Feb", "Mar", "Apr", "May", "Jun",
	"Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };

#ifndef QT_NO_DATESTRING
/*****************************************************************************
  Some static function used by QDate, QTime and QDateTime
 *****************************************************************************/

// Replaces tokens by their value. See QDateTime::toString() for a list of valid tokens
static QString getFmtString( const QString& f, const QTime* dt = 0, const QDate* dd = 0, bool am_pm = FALSE )
{
    if ( f.isEmpty() )
	return QString::null;

    QString buf = f;

    if ( dt ) {
	if ( f == "h" ) {
	    if ( ( am_pm ) && ( dt->hour() > 12 ) )
		buf = QString::number( dt->hour() - 12 );
	    else if ( ( am_pm ) && ( dt->hour() == 0 ) )
		buf = "12";
	    else
		buf = QString::number( dt->hour() );
	} else if ( f == "hh" ) {
	    if ( ( am_pm ) && ( dt->hour() > 12 ) )
		buf = QString::number( dt->hour() - 12 ).rightJustify( 2, '0', TRUE );
	    else if ( ( am_pm ) && ( dt->hour() == 0 ) )
		buf = "12";
	    else
		buf = QString::number( dt->hour() ).rightJustify( 2, '0', TRUE );
	} else if ( f == "m" ) {
	    buf = QString::number( dt->minute() );
	} else if ( f == "mm" ) {
	    buf = QString::number( dt->minute() ).rightJustify( 2, '0', TRUE );
	} else if ( f == "s" ) {
	    buf = QString::number( dt->second() );
	} else if ( f == "ss" ) {
	    buf = QString::number( dt->second() ).rightJustify( 2, '0', TRUE );
	} else if ( f == "z" ) {
	    buf = QString::number( dt->msec() );
	} else if ( f == "zzz" ) {
	    buf = QString::number( dt->msec() ).rightJustify( 3, '0', TRUE );
	} else if ( f == "ap" ) {
	    buf = dt->hour() < 12 ? "am" : "pm";
	} else if ( f == "AP" ) {
	    buf = dt->hour() < 12 ? "AM" : "PM";
	}
    }

    if ( dd ) {
	if ( f == "d" ) {
	    buf = QString::number( dd->day() );
	} else if ( f == "dd" ) {
	    buf = QString::number( dd->day() ).rightJustify( 2, '0', TRUE );
	} else if ( f == "M" ) {
	    buf = QString::number( dd->month() );
	} else if ( f == "MM" ) {
	    buf = QString::number( dd->month() ).rightJustify( 2, '0', TRUE );
#ifndef QT_NO_TEXTDATE
	} else if ( f == "ddd" ) {
	    buf = dd->shortDayName( dd->dayOfWeek() );
	} else if ( f == "dddd" ) {
	    buf = dd->longDayName( dd->dayOfWeek() );
	} else if ( f == "MMM" ) {
	    buf = dd->shortMonthName( dd->month() );
	} else if ( f == "MMMM" ) {
	    buf = dd->longMonthName( dd->month() );
#endif
	} else if ( f == "yy" ) {
	    buf = QString::number( dd->year() ).right( 2 );
	} else if ( f == "yyyy" ) {
	    buf = QString::number( dd->year() );
	}
    }

    return buf;
}

// Parses the format string and uses getFmtString to get the values for the tokens. Ret
static QString fmtDateTime( const QString& f, const QTime* dt = 0, const QDate* dd = 0 )
{
    if ( f.isEmpty() ) {
	return QString::null;
    }

    if ( dt && !dt->isValid() )
	return QString::null;
    if ( dd && !dd->isValid() )
	return QString::null;

    bool ap = ( f.contains( "AP" ) || f.contains( "ap" ) );

    QString buf;
    QString frm;
    QChar status = '0';

    for ( int i = 0; i < (int)f.length(); ++i ) {

	if ( f[ i ] == status ) {
	    if ( ( ap ) && ( ( f[ i ] == 'P' ) || ( f[ i ] == 'p' ) ) )
		status = '0';
	    frm += f[ i ];
	} else {
	    buf += getFmtString( frm, dt, dd, ap );
	    frm = QString::null;
	    if ( ( f[ i ] == 'h' ) || ( f[ i ] == 'm' ) || ( f[ i ] == 's' ) || ( f[ i ] == 'z' ) ) {
		status = f[ i ];
		frm += f[ i ];
	    } else if ( ( f[ i ] == 'd' ) || ( f[ i ] == 'M' ) || ( f[ i ] == 'y' ) ) {
		status = f[ i ];
		frm += f[ i ];
	    } else if ( ( ap ) && ( f[ i ] == 'A' ) ) {
		status = 'P';
		frm += f[ i ];
	    } else  if( ( ap ) && ( f[ i ] == 'a' ) ) {
		status = 'p';
		frm += f[ i ];
	    } else {
		buf += f[ i ];
		status = '0';
	    }
	}
    }

    buf += getFmtString( frm, dt, dd, ap );

    return buf;
}
#endif // QT_NO_DATESTRING

/*****************************************************************************
  QDate member functions
 *****************************************************************************/

/*!
    \class QDate qdatetime.h
    \reentrant
    \brief The QDate class provides date functions.

    \ingroup time
    \mainclass

    A QDate object contains a calendar date, i.e. year, month, and day
    numbers, in the modern Western (Gregorian) calendar. It can read
    the current date from the system clock. It provides functions for
    comparing dates and for manipulating dates, e.g. by adding a
    number of days or months or years.

    A QDate object is typically created either by giving the year,
    month and day numbers explicitly, or by using the static function
    currentDate(), which creates a QDate object containing the system
    clock's date. An explicit date can also be set using setYMD(). The
    fromString() function returns a QDate given a string and a date
    format which is used to interpret the date within the string.

    The year(), month(), and day() functions provide access to the
    year, month, and day numbers. Also, dayOfWeek() and dayOfYear()
    functions are provided. The same information is provided in
    textual format by the toString(), shortDayName(), longDayName(),
    shortMonthName() and longMonthName() functions.

    QDate provides a full set of operators to compare two QDate
    objects where smaller means earlier and larger means later.

    You can increment (or decrement) a date by a given number of days
    using addDays(). Similarly you can use addMonths() and addYears().
    The daysTo() function returns the number of days between two
    dates.

    The daysInMonth() and daysInYear() functions return how many days
    there are in this date's month and year, respectively. The
    leapYear() function indicates whether this date is in a leap year.

    Note that QDate should not be used for date calculations for dates
    prior to the introduction of the Gregorian calendar. This calendar
    was adopted by England from the 14<sup><small>th</small></sup>
    September 1752 (hence this is the earliest valid QDate), and
    subsequently by most other Western countries, until 1923.

    The end of time is reached around the year 8000, by which time we
    expect Qt to be obsolete.

    \sa QTime QDateTime QDateEdit QDateTimeEdit
*/

/*!
    \enum Qt::DateFormat

    \value TextDate (default) Qt format
    \value ISODate ISO 8601 extended format (YYYY-MM-DD, or with time,
    YYYY-MM-DDTHH:MM:SS)
    \value LocalDate locale dependent format
*/


/*!
    \enum Qt::TimeSpec

    \value LocalTime Locale dependent time (Timezones and Daylight Savings Time)
    \value UTC Coordinated Universal Time, replaces Greenwich Time
*/

/*!
    \fn QDate::QDate()

    Constructs a null date. Null dates are invalid.

    \sa isNull(), isValid()
*/


/*!
    Constructs a date with year \a y, month \a m and day \a d.

    \a y must be in the range 1752..8000, \a m must be in the range
    1..12, and \a d must be in the range 1..31.

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

    \sa isValid()
*/

QDate::QDate( int y, int m, int d )
{
    jd = 0;
    setYMD( y, m, d );
}


/*!
    \fn bool QDate::isNull() const

    Returns TRUE if the date is null; otherwise returns FALSE. A null
    date is invalid.

    \sa isValid()
*/


/*!
    Returns TRUE if this date is valid; otherwise returns FALSE.

    \sa isNull()
*/

bool QDate::isValid() const
{
    return jd >= FIRST_DAY;
}


/*!
    Returns the year (1752..8000) of this date.

    \sa month(), day()
*/

int QDate::year() const
{
    int y, m, d;
    julianToGregorian( jd, y, m, d );
    return y;
}

/*!
    Returns the month (January=1..December=12) of this date.

    \sa year(), day()
*/

int QDate::month() const
{
    int y, m, d;
    julianToGregorian( jd, y, m, d );
    return m;
}

/*!
    Returns the day of the month (1..31) of this date.

    \sa year(), month(), dayOfWeek()
*/

int QDate::day() const
{
    int y, m, d;
    julianToGregorian( jd, y, m, d );
    return d;
}

/*!
    Returns the weekday (Monday=1..Sunday=7) for this date.

    \sa day(), dayOfYear()
*/

int QDate::dayOfWeek() const
{
    return ( jd % 7 ) + 1;
}

/*!
    Returns the day of the year (1..365) for this date.

    \sa day(), dayOfWeek()
*/

int QDate::dayOfYear() const
{
    return jd - gregorianToJulian(year(), 1, 1) + 1;
}

/*!
    Returns the number of days in the month (28..31) for this date.

    \sa day(), daysInYear()
*/

int QDate::daysInMonth() const
{
    int y, m, d;
    julianToGregorian( jd, y, m, d );
    if ( m == 2 && leapYear(y) )
	return 29;
    else
	return monthDays[m];
}

/*!
    Returns the number of days in the year (365 or 366) for this date.

    \sa day(), daysInMonth()
*/

int QDate::daysInYear() const
{
    int y, m, d;
    julianToGregorian( jd, y, m, d );
    return leapYear( y ) ? 366 : 365;
}

/*!
  Returns the week number (1 to 53), and stores the year in \a
  *yearNumber unless \a yearNumber is null (the default).

  Returns 0 if the date is invalid.

  In accordance with ISO 8601, weeks start on Monday and the first
  Thursday of a year is always in week 1 of that year. Most years
  have 52 weeks, but some have 53.

  \a *yearNumber is not always the same as year(). For example, 1
  January 2000 has week number 52 in the year 1999, and 31 December
  2002 has week number 1 in the year 2003.

  \sa isValid()
*/

int QDate::weekNumber( int *yearNumber ) const
{
    if ( !isValid() )
	return 0;

    int dow = dayOfWeek();
    int doy = dayOfYear();
    int currYear = year();
    int jan1WeekDay = QDate( currYear, 1, 1 ).dayOfWeek();
    int yearNum;
    int weekNum;

    if ( doy <= (8 - jan1WeekDay) && jan1WeekDay > 4 ) {
	yearNum = currYear - 1;
	weekNum = 52;
	if ( jan1WeekDay == 5 ||
	     (jan1WeekDay == 6 && QDate::leapYear(yearNum)) )
	    weekNum++;
    } else {
	int totalDays = 365;
	if ( QDate::leapYear(currYear) )
	    totalDays++;

	if ( (totalDays - doy < 4 - dow)
	     || (jan1WeekDay == 7 && totalDays - doy < 3) ) {
	    yearNum = currYear + 1;
	    weekNum = 1;
	} else {
	    int j = doy + ( 7 - dow ) + ( jan1WeekDay - 1 );
	    yearNum = currYear;
	    weekNum = j / 7;
	    if ( jan1WeekDay > 4 )
		weekNum--;
	}
    }
    if ( yearNumber )
	*yearNumber = yearNum;
    return weekNum;
}

/*!
  \fn QString QDate::monthName( int month )
  \obsolete

  Use shortMonthName() instead.
*/
#ifndef QT_NO_TEXTDATE
/*!
    Returns the name of the \a month.

    1 = "Jan", 2 = "Feb", ... 12 = "Dec"

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

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

QString QDate::shortMonthName( int month )
{
#if defined(QT_CHECK_RANGE)
    if ( month < 1 || month > 12 ) {
	qWarning( "QDate::shortMonthName: Parameter out ouf range" );
	month = 1;
    }
#endif
#ifndef Q_WS_WIN
    char buffer[255];
    tm tt;
    memset( &tt, 0, sizeof( tm ) );
    tt.tm_mon = month - 1;
    if ( strftime( buffer, sizeof( buffer ), "%b", &tt ) )
	return QString::fromLocal8Bit( buffer );
#else
    SYSTEMTIME st;
    memset( &st, 0, sizeof(SYSTEMTIME) );
    st.wYear = 2000;
    st.wMonth = month;
    st.wDay = 1;
    const wchar_t mmm_t[] = L"MMM"; // workaround for Borland
    QT_WA( {
	TCHAR buf[255];
	if ( GetDateFormat( LOCALE_USER_DEFAULT, 0, &st, mmm_t, buf, 255 ) )