i18npool/source/calendar/calendar_jewish.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20
  21 #include <calendar_jewish.hxx>
  22 #include <nativenumbersupplier.hxx>
  23
  24 #include <com/sun/star/i18n/CalendarDisplayCode.hpp>
  25 #include <com/sun/star/i18n/NativeNumberMode.hpp>
  26
  27 using namespace ::com::sun::star::i18n;
  28
  29 namespace i18npool {
  30
  31 // not used
  32 //static UErrorCode status; // status is shared in all calls to Calendar, it has to be reset for each call.
  33
  34 Calendar_jewish::Calendar_jewish()
  35 {
  36     cCalendar = u"com.sun.star.i18n.Calendar_jewish"_ustr;
  37 }
  38
  39 // The following C++ code is translated from the Lisp code in
  40 // ``Calendrical Calculations'' by Nachum Dershowitz and Edward M. Reingold,
  41 // Software---Practice & Experience, vol. 20, no. 9 (September, 1990),
  42 // pp. 899--928.
  43
  44 // This code is in the public domain, but any use of it
  45 // should acknowledge its source.
  46 // https://web.archive.org/web/20010222054702/http://www.ntu.edu.sg/home/ayxyan/date1.txt
  47
  48 // Hebrew dates
  49
  50 const int HebrewEpoch = -1373429; // Absolute date of start of Hebrew calendar
  51
  52 // True if year is an Hebrew leap year
  53 static bool HebrewLeapYear(sal_Int32 year) {
  54     return ((((7 * year) + 1) % 19) < 7);
  55 }
  56
  57 // Last month of Hebrew year.
  58 static sal_Int32 LastMonthOfHebrewYear(sal_Int32 year) {
  59     return  (HebrewLeapYear(year)) ? 13 : 12;
  60 }
  61
  62 // Number of days elapsed from the Sunday prior to the start of the
  63 // Hebrew calendar to the mean conjunction of Tishri of Hebrew year.
  64 static sal_Int32 HebrewCalendarElapsedDays(sal_Int32 year) {
  65     sal_Int32 MonthsElapsed =
  66         (235 * ((year - 1) / 19))           // Months in complete cycles so far.
  67         + (12 * ((year - 1) % 19))          // Regular months in this cycle.
  68         + (7 * ((year - 1) % 19) + 1) / 19; // Leap months this cycle
  69     sal_Int32 PartsElapsed = 204 + 793 * (MonthsElapsed % 1080);
  70     int HoursElapsed =
  71         5 + 12 * MonthsElapsed + 793 * (MonthsElapsed  / 1080)
  72         + PartsElapsed / 1080;
  73     sal_Int32 ConjunctionDay = 1 + 29 * MonthsElapsed + HoursElapsed / 24;
  74     sal_Int32 ConjunctionParts = 1080 * (HoursElapsed % 24) + PartsElapsed % 1080;
  75     sal_Int32 AlternativeDay;
  76
  77     if ((ConjunctionParts >= 19440)        // If new moon is at or after midday,
  78           || (((ConjunctionDay % 7) == 2)    // ...or is on a Tuesday...
  79           && (ConjunctionParts >= 9924)  // at 9 hours, 204 parts or later...
  80           && !(HebrewLeapYear(year)))   // ...of a common year,
  81           || (((ConjunctionDay % 7) == 1)    // ...or is on a Monday at...
  82           && (ConjunctionParts >= 16789) // 15 hours, 589 parts or later...
  83           && (HebrewLeapYear(year - 1))))// at the end of a leap year
  84         // Then postpone Rosh HaShanah one day
  85         AlternativeDay = ConjunctionDay + 1;
  86     else
  87         AlternativeDay = ConjunctionDay;
  88
  89     if (((AlternativeDay % 7) == 0)// If Rosh HaShanah would occur on Sunday,
  90           || ((AlternativeDay % 7) == 3)     // or Wednesday,
  91           || ((AlternativeDay % 7) == 5))    // or Friday
  92         // Then postpone it one (more) day
  93         return (1+ AlternativeDay);
  94     else
  95         return AlternativeDay;
  96 }
  97
  98 // Number of days in Hebrew year.
  99 static sal_Int32 DaysInHebrewYear(sal_Int32 year) {
 100     return ((HebrewCalendarElapsedDays(year + 1)) -
 101           (HebrewCalendarElapsedDays(year)));
 102 }
 103
 104 // True if Heshvan is long in Hebrew year.
 105 static bool LongHeshvan(sal_Int32 year) {
 106     return ((DaysInHebrewYear(year) % 10) == 5);
 107 }
 108
 109 // True if Kislev is short in Hebrew year.
 110 static bool ShortKislev(sal_Int32 year) {
 111     return ((DaysInHebrewYear(year) % 10) == 3);
 112 }
 113
 114 // Last day of month in Hebrew year.
 115 static sal_Int32 LastDayOfHebrewMonth(sal_Int32 month, sal_Int32 year) {
 116     if ((month == 2)
 117         || (month == 4)
 118         || (month == 6)
 119         || ((month == 8) && !(LongHeshvan(year)))
 120         || ((month == 9) && ShortKislev(year))
 121         || (month == 10)
 122         || ((month == 12) && !(HebrewLeapYear(year)))
 123         || (month == 13))
 124         return 29;
 125     else
 126         return 30;
 127 }
 128
 129 namespace {
 130
 131 class HebrewDate {
 132 private:
 133     sal_Int32 year;   // 1...
 134     sal_Int32 month;  // 1..LastMonthOfHebrewYear(year)
 135     sal_Int32 day;    // 1..LastDayOfHebrewMonth(month, year)
 136
 137 public:
 138     HebrewDate(sal_Int32 m, sal_Int32 d, sal_Int32 y) : year(y), month(m), day(d) { }
 139
 140     explicit HebrewDate(sal_Int32 d) { // Computes the Hebrew date from the absolute date.
 141
 142     if (d == 730119) // 1999-12-31 : a very common date used in calc
 143     {
 144         year = 5760;
 145         month = 10;
 146         day = 22;
 147         return;
 148     }
 149
 150     year = (d + HebrewEpoch) / 366; // Approximation from below.
 151     // Search forward for year from the approximation.
 152     while (d >= HebrewDate(7,1,year + 1).GetAbsoluteDate())
 153       year++;
 154     // Search forward for month from either Tishri or Nisan.
 155     if (d < HebrewDate(1, 1, year).GetAbsoluteDate())
 156       month = 7;  //  Start at Tishri
 157     else
 158       month = 1;  //  Start at Nisan
 159     while (d > HebrewDate(month, (LastDayOfHebrewMonth(month,year)), year).GetAbsoluteDate())
 160       month++;
 161     // Calculate the day by subtraction.
 162     day = d - HebrewDate(month, 1, year).GetAbsoluteDate() + 1;
 163     }
 164
 165     int GetAbsoluteDate() const { // Computes the absolute date of Hebrew date.
 166     sal_Int32 DayInYear = day; // Days so far this month.
 167     if (month < 7) { // Before Tishri, so add days in prior months
 168              // this year before and after Nisan.
 169       sal_Int32 m = 7;
 170       while (m <= (LastMonthOfHebrewYear(year))) {
 171         DayInYear = DayInYear + LastDayOfHebrewMonth(m, year);
 172         m++;
 173       };
 174       m = 1;
 175       while (m < month) {
 176         DayInYear = DayInYear + LastDayOfHebrewMonth(m, year);
 177         m++;
 178       }
 179     }
 180     else { // Add days in prior months this year
 181       sal_Int32 m = 7;
 182       while (m < month) {
 183         DayInYear = DayInYear + LastDayOfHebrewMonth(m, year);
 184         m++;
 185       }
 186     }
 187     return (DayInYear +
 188         (HebrewCalendarElapsedDays(year)// Days in prior years.
 189          + HebrewEpoch));         // Days elapsed before absolute date 1.
 190     }
 191
 192     sal_Int32 GetMonth() const { return month; }
 193     sal_Int32 GetDay() const { return day; }
 194     sal_Int32 GetYear() const { return year; }
 195
 196 };
 197
 198 }
 199
 200 //  Gregorian dates
 201
 202 static int LastDayOfGregorianMonth(int month, int year) {
 203 // Compute the last date of the month for the Gregorian calendar.
 204
 205     switch (month) {
 206     case 2:
 207     if ((((year % 4) == 0) && ((year % 100) != 0))
 208         || ((year % 400) == 0))
 209       return 29;
 210     else
 211       return 28;
 212     case 4:
 213     case 6:
 214     case 9:
 215     case 11: return 30;
 216     default: return 31;
 217     }
 218 }
 219
 220 namespace {
 221
 222 class GregorianDate {
 223 private:
 224     int year;   // 1...
 225     int month;  // 1 == January, ..., 12 == December
 226     int day;    // 1..LastDayOfGregorianMonth(month, year)
 227
 228 public:
 229     GregorianDate(int m, int d, int y) { month = m; day = d; year = y; }
 230
 231     explicit GregorianDate(int d) { // Computes the Gregorian date from the absolute date.
 232         // Search forward year by year from approximate year
 233         year = d/366;
 234         while (d >= GregorianDate(1,1,year+1).GetAbsoluteDate())
 235           year++;
 236         // Search forward month by month from January
 237         month = 1;
 238         while (d > GregorianDate(month, LastDayOfGregorianMonth(month,year), year).GetAbsoluteDate())
 239           month++;
 240         day = d - GregorianDate(month,1,year).GetAbsoluteDate() + 1;
 241     }
 242
 243     int GetAbsoluteDate() const { // Computes the absolute date from the Gregorian date.
 244         int N = day;           // days this month
 245         for (int m = month - 1;  m > 0; m--) // days in prior months this year
 246           N = N + LastDayOfGregorianMonth(m, year);
 247         return
 248           (N                    // days this year
 249            + 365 * (year - 1)   // days in previous years ignoring leap days
 250            + (year - 1)/4       // Julian leap days before this year...
 251            - (year - 1)/100     // ...minus prior century years...
 252            + (year - 1)/400);   // ...plus prior years divisible by 400
 253     }
 254
 255     int GetMonth() const { return month; }
 256     int GetDay() const { return day; }
 257     int GetYear() const { return year; }
 258
 259 };
 260
 261 }
 262
 263 // map field value from gregorian calendar to other calendar, it can be overwritten by derived class.
 264 void Calendar_jewish::mapFromGregorian()
 265 {
 266     int y = fieldValue[CalendarFieldIndex::YEAR];
 267     if (fieldValue[CalendarFieldIndex::ERA] == 0)
 268         y = 1 - y;
 269     GregorianDate Temp(fieldValue[CalendarFieldIndex::MONTH] + 1, fieldValue[CalendarFieldIndex::DAY_OF_MONTH], y);
 270     HebrewDate hd(Temp.GetAbsoluteDate());
 271
 272     fieldValue[CalendarFieldIndex::ERA] = hd.GetYear() <= 0 ? 0 : 1;
 273     fieldValue[CalendarFieldIndex::MONTH] = sal::static_int_cast<sal_Int16>( hd.GetMonth() - 1 );
 274     fieldValue[CalendarFieldIndex::DAY_OF_MONTH] = static_cast<sal_Int16>(hd.GetDay());
 275     fieldValue[CalendarFieldIndex::YEAR] = static_cast<sal_Int16>(hd.GetYear() <= 0 ? 1 - hd.GetYear() : hd.GetYear());
 276 }
 277
 278 #define FIELDS  ((1 << CalendarFieldIndex::ERA) | (1 << CalendarFieldIndex::YEAR) | (1 << CalendarFieldIndex::MONTH) | (1 << CalendarFieldIndex::DAY_OF_MONTH))
 279 // map field value from other calendar to gregorian calendar, it should be implemented.
 280 void Calendar_jewish::mapToGregorian()
 281 {
 282     if (!(fieldSet & FIELDS))
 283         return;
 284
 285     sal_Int16 y = fieldSetValue[CalendarFieldIndex::YEAR];
 286     if (fieldSetValue[CalendarFieldIndex::ERA] == 0)
 287         y = 1 - y;
 288     HebrewDate Temp(fieldSetValue[CalendarFieldIndex::MONTH] + 1, fieldSetValue[CalendarFieldIndex::DAY_OF_MONTH], y);
 289     GregorianDate gd(Temp.GetAbsoluteDate());
 290
 291     fieldSetValue[CalendarFieldIndex::ERA] = gd.GetYear() <= 0 ? 0 : 1;
 292     fieldSetValue[CalendarFieldIndex::MONTH] = sal::static_int_cast<sal_Int16>( gd.GetMonth() - 1 );
 293     fieldSetValue[CalendarFieldIndex::DAY_OF_MONTH] = static_cast<sal_Int16>(gd.GetDay());
 294     fieldSetValue[CalendarFieldIndex::YEAR] = static_cast<sal_Int16>(gd.GetYear() <= 0 ? 1 - gd.GetYear() : gd.GetYear());
 295     fieldSet |= FIELDS;
 296 }
 297
 298 // Methods in XExtendedCalendar
 299 OUString SAL_CALL
 300 Calendar_jewish::getDisplayString( sal_Int32 nCalendarDisplayCode, sal_Int16 /*nNativeNumberMode*/ )
 301 {
 302     const sal_Int16 nNativeNumberMode = NativeNumberMode::NATNUM2;  // make Hebrew number for Jewish calendar
 303
 304     if (nCalendarDisplayCode == CalendarDisplayCode::SHORT_YEAR) {
 305         sal_Int32 value = getValue(CalendarFieldIndex::YEAR) % 1000; // take last 3 digits
 306         return mxNatNum->getNativeNumberString(OUString::number(value), aLocale, nNativeNumberMode );
 307     }
 308     else
 309         return Calendar_gregorian::getDisplayString(nCalendarDisplayCode, nNativeNumberMode );
 310 }
 311
 312 }
 313
 314 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */