source/calendar/calendar_jewish.cxx

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// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_i18npool.hxx"

#include <math.h>
#include <stdio.h>

#include "calendar_jewish.hxx"

using namespace ::com::sun::star::uno;
using namespace ::com::sun::star::lang;
using namespace ::com::sun::star::i18n;
using namespace ::rtl;

#define ERROR RuntimeException()

// not used
//static UErrorCode status; // status is shared in all calls to Calendar, it has to be reset for each call.

Calendar_jewish::Calendar_jewish()
{
	cCalendar = "com.sun.star.i18n.Calendar_jewish";
}

// The following C++ code is translated from the Lisp code in
// ``Calendrical Calculations'' by Nachum Dershowitz and Edward M. Reingold,
// Software---Practice & Experience, vol. 20, no. 9 (September, 1990),
// pp. 899--928.

// This code is in the public domain, but any use of it
// should acknowledge its source.
// http://www.ntu.edu.sg/home/ayxyan/date1.txt

// Hebrew dates

const int HebrewEpoch = -1373429; // Absolute date of start of Hebrew calendar

// True if year is an Hebrew leap year
sal_Bool HebrewLeapYear(sal_Int32 year) {
	return ((((7 * year) + 1) % 19) < 7);
}

// Last month of Hebrew year.
sal_Int32 LastMonthOfHebrewYear(sal_Int32 year) {
	return  (HebrewLeapYear(year)) ? 13 : 12;
}

// Number of days elapsed from the Sunday prior to the start of the
// Hebrew calendar to the mean conjunction of Tishri of Hebrew year.
sal_Int32 HebrewCalendarElapsedDays(sal_Int32 year) {
	sal_Int32 MonthsElapsed =
	    (235 * ((year - 1) / 19))           // Months in complete cycles so far.
	    + (12 * ((year - 1) % 19))          // Regular months in this cycle.
	    + (7 * ((year - 1) % 19) + 1) / 19; // Leap months this cycle
	sal_Int32 PartsElapsed = 204 + 793 * (MonthsElapsed % 1080);
	int HoursElapsed =
	    5 + 12 * MonthsElapsed + 793 * (MonthsElapsed  / 1080)
	    + PartsElapsed / 1080;
	sal_Int32 ConjunctionDay = 1 + 29 * MonthsElapsed + HoursElapsed / 24;
	sal_Int32 ConjunctionParts = 1080 * (HoursElapsed % 24) + PartsElapsed % 1080;
	sal_Int32 AlternativeDay;

	if ((ConjunctionParts >= 19440)        // If new moon is at or after midday,
	      || (((ConjunctionDay % 7) == 2)    // ...or is on a Tuesday...
		  && (ConjunctionParts >= 9924)  // at 9 hours, 204 parts or later...
		  && !(HebrewLeapYear(year)))   // ...of a common year,
	      || (((ConjunctionDay % 7) == 1)    // ...or is on a Monday at...
		  && (ConjunctionParts >= 16789) // 15 hours, 589 parts or later...
		  && (HebrewLeapYear(year - 1))))// at the end of a leap year
	    // Then postpone Rosh HaShanah one day
	    AlternativeDay = ConjunctionDay + 1;
	else
	    AlternativeDay = ConjunctionDay;

	if (((AlternativeDay % 7) == 0)// If Rosh HaShanah would occur on Sunday,
	      || ((AlternativeDay % 7) == 3)     // or Wednesday,
	      || ((AlternativeDay % 7) == 5))    // or Friday
	    // Then postpone it one (more) day
	    return (1+ AlternativeDay);
	else
	    return AlternativeDay;
}

// Number of days in Hebrew year.
sal_Int32 DaysInHebrewYear(sal_Int32 year) {
	return ((HebrewCalendarElapsedDays(year + 1)) -
	      (HebrewCalendarElapsedDays(year)));
}

// True if Heshvan is long in Hebrew year.
sal_Bool LongHeshvan(sal_Int32 year) {
	return ((DaysInHebrewYear(year) % 10) == 5);
}

// True if Kislev is short in Hebrew year.
sal_Bool ShortKislev(sal_Int32 year) {
	return ((DaysInHebrewYear(year) % 10) == 3);
}

// Last day of month in Hebrew year.
sal_Int32 LastDayOfHebrewMonth(sal_Int32 month, sal_Int32 year) {
	if ((month == 2)
	    || (month == 4)
	    || (month == 6)
	    || ((month == 8) && !(LongHeshvan(year)))
	    || ((month == 9) && ShortKislev(year))
	    || (month == 10)
	    || ((month == 12) && !(HebrewLeapYear(year)))
	    || (month == 13))
	    return 29;
	else
	    return 30;
}


class HebrewDate {
private:
	sal_Int32 year;   // 1...
	sal_Int32 month;  // 1..LastMonthOfHebrewYear(year)
	sal_Int32 day;    // 1..LastDayOfHebrewMonth(month, year)

public:
	HebrewDate(sal_Int32 m, sal_Int32 d, sal_Int32 y) { month = m; day = d; year = y; }

	HebrewDate(sal_Int32 d) { // Computes the Hebrew date from the absolute date.
	year = (d + HebrewEpoch) / 366; // Approximation from below.
	// Search forward for year from the approximation.
	while (d >= HebrewDate(7,1,year + 1))
	  year++;
	// Search forward for month from either Tishri or Nisan.
	if (d < HebrewDate(1, 1, year))
	  month = 7;  //  Start at Tishri
	else
	  month = 1;  //  Start at Nisan
	while (d > HebrewDate(month, (LastDayOfHebrewMonth(month,year)), year))
	  month++;
	// Calculate the day by subtraction.
	day = d - HebrewDate(month, 1, year) + 1;
	}

	operator int() { // Computes the absolute date of Hebrew date.
	sal_Int32 DayInYear = day; // Days so far this month.
	if (month < 7) { // Before Tishri, so add days in prior months
			 // this year before and after Nisan.
	  sal_Int32 m = 7;
	  while (m <= (LastMonthOfHebrewYear(year))) {
	    DayInYear = DayInYear + LastDayOfHebrewMonth(m, year);
	    m++;
	  };
	  m = 1;
	  while (m < month) {
	    DayInYear = DayInYear + LastDayOfHebrewMonth(m, year);
	    m++;
	  }
	}
	else { // Add days in prior months this year
	  sal_Int32 m = 7;
	  while (m < month) {
	    DayInYear = DayInYear + LastDayOfHebrewMonth(m, year);
	    m++;
	  }
	}
	return (DayInYear +
		(HebrewCalendarElapsedDays(year)// Days in prior years.
		 + HebrewEpoch));         // Days elapsed before absolute date 1.
	}

	sal_Int32 GetMonth() { return month; }
	sal_Int32 GetDay() { return day; }
	sal_Int32 GetYear() { return year; }

};

//  Gregorian dates

int LastDayOfGregorianMonth(int month, int year) {
// Compute the last date of the month for the Gregorian calendar.

	switch (month) {
	case 2:
	if ((((year % 4) == 0) && ((year % 100) != 0))
	    || ((year % 400) == 0))
	  return 29;
	else
	  return 28;
	case 4:
	case 6:
	case 9:
	case 11: return 30;
	default: return 31;
	}
}

class GregorianDate {
private:
	int year;   // 1...
	int month;  // 1 == January, ..., 12 == December
	int day;    // 1..LastDayOfGregorianMonth(month, year)

public:
	GregorianDate(int m, int d, int y) { month = m; day = d; year = y; }

	GregorianDate(int d) { // Computes the Gregorian date from the absolute date.
	    // Search forward year by year from approximate year
	    year = d/366;
	    while (d >= GregorianDate(1,1,year+1))
	      year++;
	    // Search forward month by month from January
	    month = 1;
	    while (d > GregorianDate(month, LastDayOfGregorianMonth(month,year), year))
	      month++;
	    day = d - GregorianDate(month,1,year) + 1;
	}

	operator int() { // Computes the absolute date from the Gregorian date.
	    int N = day;           // days this month
	    for (int m = month - 1;  m > 0; m--) // days in prior months this year
	      N = N + LastDayOfGregorianMonth(m, year);
	    return
	      (N                    // days this year
	       + 365 * (year - 1)   // days in previous years ignoring leap days
	       + (year - 1)/4       // Julian leap days before this year...
	       - (year - 1)/100     // ...minus prior century years...
	       + (year - 1)/400);   // ...plus prior years divisible by 400
	}

	int GetMonth() { return month; }
	int GetDay() { return day; }
	int GetYear() { return year; }

};

// map field value from gregorian calendar to other calendar, it can be overwritten by derived class.
void Calendar_jewish::mapFromGregorian() throw(RuntimeException)
{
	int y = fieldValue[CalendarFieldIndex::YEAR];
	if (fieldValue[CalendarFieldIndex::ERA] == 0)
	    y = 1 - y;
    GregorianDate Temp(fieldValue[CalendarFieldIndex::MONTH] + 1, fieldValue[CalendarFieldIndex::DAY_OF_MONTH], y);
	HebrewDate hd(Temp);

	fieldValue[CalendarFieldIndex::ERA] = hd.GetYear() <= 0 ? 0 : 1;
	fieldValue[CalendarFieldIndex::MONTH] = sal::static_int_cast<sal_Int16>( hd.GetMonth() - 1 );
	fieldValue[CalendarFieldIndex::DAY_OF_MONTH] = (sal_Int16)hd.GetDay();
	fieldValue[CalendarFieldIndex::YEAR] = (sal_Int16)(hd.GetYear() <= 0 ? 1 - hd.GetYear() : hd.GetYear());
}

#define FIELDS  ((1 << CalendarFieldIndex::ERA) | (1 << CalendarFieldIndex::YEAR) | (1 << CalendarFieldIndex::MONTH) | (1 << CalendarFieldIndex::DAY_OF_MONTH))
// map field value from other calendar to gregorian calendar, it should be implemented.
void Calendar_jewish::mapToGregorian() throw(RuntimeException)
{
	if (fieldSet & FIELDS) {
	    sal_Int16 y = fieldSetValue[CalendarFieldIndex::YEAR];
	    if (fieldSetValue[CalendarFieldIndex::ERA] == 0)
		y = 1 - y;
        HebrewDate Temp(fieldSetValue[CalendarFieldIndex::MONTH] + 1, fieldSetValue[CalendarFieldIndex::DAY_OF_MONTH], y);
	    GregorianDate gd(Temp);

	    fieldSetValue[CalendarFieldIndex::ERA] = gd.GetYear() <= 0 ? 0 : 1;
	    fieldSetValue[CalendarFieldIndex::MONTH] = sal::static_int_cast<sal_Int16>( gd.GetMonth() - 1 );
	    fieldSetValue[CalendarFieldIndex::DAY_OF_MONTH] = (sal_Int16)gd.GetDay();
	    fieldSetValue[CalendarFieldIndex::YEAR] = (sal_Int16)(gd.GetYear() <= 0 ? 1 - gd.GetYear() : gd.GetYear());
	    fieldSet |= FIELDS;
	}
}

// Methods in XExtendedCalendar
OUString SAL_CALL
Calendar_jewish::getDisplayString( sal_Int32 nCalendarDisplayCode, sal_Int16 nNativeNumberMode )
	throw (RuntimeException)
{
    nNativeNumberMode = NativeNumberMode::NATNUM2;  // make Hebrew number for Jewish calendar

    if (nCalendarDisplayCode == CalendarDisplayCode::SHORT_YEAR) {
	    sal_Int32 value = getValue(CalendarFieldIndex::YEAR) % 1000; // take last 3 digits
	    return aNatNum.getNativeNumberString(OUString::valueOf(value), aLocale, nNativeNumberMode );
	}
	else
	    return Calendar_gregorian::getDisplayString(nCalendarDisplayCode, nNativeNumberMode );
}