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diff --git a/intl/icu/source/i18n/islamcal.h b/intl/icu/source/i18n/islamcal.h new file mode 100644 index 0000000000..fde58478c0 --- /dev/null +++ b/intl/icu/source/i18n/islamcal.h @@ -0,0 +1,431 @@ +// © 2016 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html +/* + ******************************************************************************** + * Copyright (C) 2003-2013, International Business Machines Corporation + * and others. All Rights Reserved. + ****************************************************************************** + * + * File ISLAMCAL.H + * + * Modification History: + * + * Date Name Description + * 10/14/2003 srl ported from java IslamicCalendar + ***************************************************************************** + */ + +#ifndef ISLAMCAL_H +#define ISLAMCAL_H + +#include "unicode/utypes.h" + +#if !UCONFIG_NO_FORMATTING + +#include "unicode/calendar.h" + +U_NAMESPACE_BEGIN + +/** + * <code>IslamicCalendar</code> is a subclass of <code>Calendar</code> + * that implements the Islamic civil and religious calendars. It + * is used as the civil calendar in most of the Arab world and the + * liturgical calendar of the Islamic faith worldwide. This calendar + * is also known as the "Hijri" calendar, since it starts at the time + * of Mohammed's emigration (or "hijra") to Medinah on Thursday, + * July 15, 622 AD (Julian). + * <p> + * The Islamic calendar is strictly lunar, and thus an Islamic year of twelve + * lunar months does not correspond to the solar year used by most other + * calendar systems, including the Gregorian. An Islamic year is, on average, + * about 354 days long, so each successive Islamic year starts about 11 days + * earlier in the corresponding Gregorian year. + * <p> + * Each month of the calendar starts when the new moon's crescent is visible + * at sunset. However, in order to keep the time fields in this class + * synchronized with those of the other calendars and with local clock time, + * we treat days and months as beginning at midnight, + * roughly 6 hours after the corresponding sunset. + * <p> + * There are two main variants of the Islamic calendar in existence. The first + * is the <em>civil</em> calendar, which uses a fixed cycle of alternating 29- + * and 30-day months, with a leap day added to the last month of 11 out of + * every 30 years. This calendar is easily calculated and thus predictable in + * advance, so it is used as the civil calendar in a number of Arab countries. + * This is the default behavior of a newly-created <code>IslamicCalendar</code> + * object. + * <p> + * The Islamic <em>religious</em> calendar, however, is based on the <em>observation</em> + * of the crescent moon. It is thus affected by the position at which the + * observations are made, seasonal variations in the time of sunset, the + * eccentricities of the moon's orbit, and even the weather at the observation + * site. This makes it impossible to calculate in advance, and it causes the + * start of a month in the religious calendar to differ from the civil calendar + * by up to three days. + * <p> + * Using astronomical calculations for the position of the sun and moon, the + * moon's illumination, and other factors, it is possible to determine the start + * of a lunar month with a fairly high degree of certainty. However, these + * calculations are extremely complicated and thus slow, so most algorithms, + * including the one used here, are only approximations of the true astronical + * calculations. At present, the approximations used in this class are fairly + * simplistic; they will be improved in later versions of the code. + * <p> + * The {@link #setCivil setCivil} method determines + * which approach is used to determine the start of a month. By default, the + * fixed-cycle civil calendar is used. However, if <code>setCivil(false)</code> + * is called, an approximation of the true lunar calendar will be used. + * + * @see GregorianCalendar + * + * @author Laura Werner + * @author Alan Liu + * @author Steven R. Loomis + * @internal + */ +class U_I18N_API IslamicCalendar : public Calendar { + public: + //------------------------------------------------------------------------- + // Constants... + //------------------------------------------------------------------------- + + /** + * Calendar type - civil or religious or um alqura + * @internal + */ + enum ECalculationType { + ASTRONOMICAL, + CIVIL, + UMALQURA, + TBLA + }; + + /** + * Constants for the months + * @internal + */ + enum EMonths { + /** + * Constant for Muharram, the 1st month of the Islamic year. + * @internal + */ + MUHARRAM = 0, + + /** + * Constant for Safar, the 2nd month of the Islamic year. + * @internal + */ + SAFAR = 1, + + /** + * Constant for Rabi' al-awwal (or Rabi' I), the 3rd month of the Islamic year. + * @internal + */ + RABI_1 = 2, + + /** + * Constant for Rabi' al-thani or (Rabi' II), the 4th month of the Islamic year. + * @internal + */ + RABI_2 = 3, + + /** + * Constant for Jumada al-awwal or (Jumada I), the 5th month of the Islamic year. + * @internal + */ + JUMADA_1 = 4, + + /** + * Constant for Jumada al-thani or (Jumada II), the 6th month of the Islamic year. + * @internal + */ + JUMADA_2 = 5, + + /** + * Constant for Rajab, the 7th month of the Islamic year. + * @internal + */ + RAJAB = 6, + + /** + * Constant for Sha'ban, the 8th month of the Islamic year. + * @internal + */ + SHABAN = 7, + + /** + * Constant for Ramadan, the 9th month of the Islamic year. + * @internal + */ + RAMADAN = 8, + + /** + * Constant for Shawwal, the 10th month of the Islamic year. + * @internal + */ + SHAWWAL = 9, + + /** + * Constant for Dhu al-Qi'dah, the 11th month of the Islamic year. + * @internal + */ + DHU_AL_QIDAH = 10, + + /** + * Constant for Dhu al-Hijjah, the 12th month of the Islamic year. + * @internal + */ + DHU_AL_HIJJAH = 11, + + ISLAMIC_MONTH_MAX + }; + + + //------------------------------------------------------------------------- + // Constructors... + //------------------------------------------------------------------------- + + /** + * Constructs an IslamicCalendar based on the current time in the default time zone + * with the given locale. + * + * @param aLocale The given locale. + * @param success Indicates the status of IslamicCalendar object construction. + * Returns U_ZERO_ERROR if constructed successfully. + * @param type The Islamic calendar calculation type. The default value is CIVIL. + * @internal + */ + IslamicCalendar(const Locale& aLocale, UErrorCode &success, ECalculationType type = CIVIL); + + /** + * Copy Constructor + * @internal + */ + IslamicCalendar(const IslamicCalendar& other); + + /** + * Destructor. + * @internal + */ + virtual ~IslamicCalendar(); + + /** + * Sets Islamic calendar calculation type used by this instance. + * + * @param type The calendar calculation type, <code>CIVIL</code> to use the civil + * calendar, <code>ASTRONOMICAL</code> to use the astronomical calendar. + * @internal + */ + void setCalculationType(ECalculationType type, UErrorCode &status); + + /** + * Returns <code>true</code> if this object is using the fixed-cycle civil + * calendar, or <code>false</code> if using the religious, astronomical + * calendar. + * @internal + */ + UBool isCivil(); + + + // TODO: copy c'tor, etc + + // clone + virtual IslamicCalendar* clone() const; + + private: + /** + * Determine whether a year is a leap year in the Islamic civil calendar + */ + static UBool civilLeapYear(int32_t year); + + /** + * Return the day # on which the given year starts. Days are counted + * from the Hijri epoch, origin 0. + */ + int32_t yearStart(int32_t year) const; + + /** + * Return the day # on which the given month starts. Days are counted + * from the Hijri epoch, origin 0. + * + * @param year The hijri year + * @param year The hijri month, 0-based + */ + int32_t monthStart(int32_t year, int32_t month) const; + + /** + * Find the day number on which a particular month of the true/lunar + * Islamic calendar starts. + * + * @param month The month in question, origin 0 from the Hijri epoch + * + * @return The day number on which the given month starts. + */ + int32_t trueMonthStart(int32_t month) const; + + /** + * Return the "age" of the moon at the given time; this is the difference + * in ecliptic latitude between the moon and the sun. This method simply + * calls CalendarAstronomer.moonAge, converts to degrees, + * and adjusts the resultto be in the range [-180, 180]. + * + * @param time The time at which the moon's age is desired, + * in millis since 1/1/1970. + */ + static double moonAge(UDate time, UErrorCode &status); + + //------------------------------------------------------------------------- + // Internal data.... + // + + /** + * <code>CIVIL</code> if this object uses the fixed-cycle Islamic civil calendar, + * and <code>ASTRONOMICAL</code> if it approximates the true religious calendar using + * astronomical calculations for the time of the new moon. + */ + ECalculationType cType; + + //---------------------------------------------------------------------- + // Calendar framework + //---------------------------------------------------------------------- + protected: + /** + * @internal + */ + virtual int32_t handleGetLimit(UCalendarDateFields field, ELimitType limitType) const; + + /** + * Return the length (in days) of the given month. + * + * @param year The hijri year + * @param year The hijri month, 0-based + * @internal + */ + virtual int32_t handleGetMonthLength(int32_t extendedYear, int32_t month) const; + + /** + * Return the number of days in the given Islamic year + * @internal + */ + virtual int32_t handleGetYearLength(int32_t extendedYear) const; + + //------------------------------------------------------------------------- + // Functions for converting from field values to milliseconds.... + //------------------------------------------------------------------------- + + // Return JD of start of given month/year + /** + * @internal + */ + virtual int32_t handleComputeMonthStart(int32_t eyear, int32_t month, UBool useMonth) const; + + //------------------------------------------------------------------------- + // Functions for converting from milliseconds to field values + //------------------------------------------------------------------------- + + /** + * @internal + */ + virtual int32_t handleGetExtendedYear(); + + /** + * Override Calendar to compute several fields specific to the Islamic + * calendar system. These are: + * + * <ul><li>ERA + * <li>YEAR + * <li>MONTH + * <li>DAY_OF_MONTH + * <li>DAY_OF_YEAR + * <li>EXTENDED_YEAR</ul> + * + * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this + * method is called. The getGregorianXxx() methods return Gregorian + * calendar equivalents for the given Julian day. + * @internal + */ + virtual void handleComputeFields(int32_t julianDay, UErrorCode &status); + + // UObject stuff + public: + /** + * @return The class ID for this object. All objects of a given class have the + * same class ID. Objects of other classes have different class IDs. + * @internal + */ + virtual UClassID getDynamicClassID(void) const; + + /** + * Return the class ID for this class. This is useful only for comparing to a return + * value from getDynamicClassID(). For example: + * + * Base* polymorphic_pointer = createPolymorphicObject(); + * if (polymorphic_pointer->getDynamicClassID() == + * Derived::getStaticClassID()) ... + * + * @return The class ID for all objects of this class. + * @internal + */ + /*U_I18N_API*/ static UClassID U_EXPORT2 getStaticClassID(void); + + /** + * return the calendar type, "buddhist". + * + * @return calendar type + * @internal + */ + virtual const char * getType() const; + + private: + IslamicCalendar(); // default constructor not implemented + + // Default century. + protected: + + /** + * (Overrides Calendar) Return true if the current date for this Calendar is in + * Daylight Savings Time. Recognizes DST_OFFSET, if it is set. + * + * @param status Fill-in parameter which receives the status of this operation. + * @return True if the current date for this Calendar is in Daylight Savings Time, + * false, otherwise. + * @internal + */ + virtual UBool inDaylightTime(UErrorCode& status) const; + + + /** + * Returns TRUE because the Islamic Calendar does have a default century + * @internal + */ + virtual UBool haveDefaultCentury() const; + + /** + * Returns the date of the start of the default century + * @return start of century - in milliseconds since epoch, 1970 + * @internal + */ + virtual UDate defaultCenturyStart() const; + + /** + * Returns the year in which the default century begins + * @internal + */ + virtual int32_t defaultCenturyStartYear() const; + + private: + /** + * Initializes the 100-year window that dates with 2-digit years + * are considered to fall within so that its start date is 80 years + * before the current time. + */ + static void U_CALLCONV initializeSystemDefaultCentury(void); +}; + +U_NAMESPACE_END + +#endif +#endif + + + |