i18npool/source/calendar/calendar_jewish.cxx

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