michael@0: /* michael@0: ***************************************************************************** michael@0: * Copyright (C) 2007-2013, International Business Machines Corporation michael@0: * and others. All Rights Reserved. michael@0: ***************************************************************************** michael@0: * michael@0: * File CHNSECAL.H michael@0: * michael@0: * Modification History: michael@0: * michael@0: * Date Name Description michael@0: * 9/18/2007 ajmacher ported from java ChineseCalendar michael@0: ***************************************************************************** michael@0: */ michael@0: michael@0: #ifndef CHNSECAL_H michael@0: #define CHNSECAL_H michael@0: michael@0: #include "unicode/utypes.h" michael@0: michael@0: #if !UCONFIG_NO_FORMATTING michael@0: michael@0: #include "unicode/calendar.h" michael@0: #include "unicode/timezone.h" michael@0: michael@0: U_NAMESPACE_BEGIN michael@0: michael@0: /** michael@0: * ChineseCalendar is a concrete subclass of {@link Calendar} michael@0: * that implements a traditional Chinese calendar. The traditional Chinese michael@0: * calendar is a lunisolar calendar: Each month starts on a new moon, and michael@0: * the months are numbered according to solar events, specifically, to michael@0: * guarantee that month 11 always contains the winter solstice. In order michael@0: * to accomplish this, leap months are inserted in certain years. Leap michael@0: * months are numbered the same as the month they follow. The decision of michael@0: * which month is a leap month depends on the relative movements of the sun michael@0: * and moon. michael@0: * michael@0: *

This class defines one addition field beyond those defined by michael@0: * Calendar: The IS_LEAP_MONTH field takes the michael@0: * value of 0 for normal months, or 1 for leap months. michael@0: * michael@0: *

All astronomical computations are performed with respect to a time michael@0: * zone of GMT+8:00 and a longitude of 120 degrees east. Although some michael@0: * calendars implement a historically more accurate convention of using michael@0: * Beijing's local longitude (116 degrees 25 minutes east) and time zone michael@0: * (GMT+7:45:40) for dates before 1929, we do not implement this here. michael@0: * michael@0: *

Years are counted in two different ways in the Chinese calendar. The michael@0: * first method is by sequential numbering from the 61st year of the reign michael@0: * of Huang Di, 2637 BCE, which is designated year 1 on the Chinese michael@0: * calendar. The second method uses 60-year cycles from the same starting michael@0: * point, which is designated year 1 of cycle 1. In this class, the michael@0: * EXTENDED_YEAR field contains the sequential year count. michael@0: * The ERA field contains the cycle number, and the michael@0: * YEAR field contains the year of the cycle, a value between michael@0: * 1 and 60. michael@0: * michael@0: *

There is some variation in what is considered the starting point of michael@0: * the calendar, with some sources starting in the first year of the reign michael@0: * of Huang Di, rather than the 61st. This gives continuous year numbers michael@0: * 60 years greater and cycle numbers one greater than what this class michael@0: * implements. michael@0: * michael@0: *

Because ChineseCalendar defines an additional field and michael@0: * redefines the way the ERA field is used, it requires a new michael@0: * format class, ChineseDateFormat. As always, use the michael@0: * methods DateFormat.getXxxInstance(Calendar cal,...) to michael@0: * obtain a formatter for this calendar. michael@0: * michael@0: *

References:

michael@0: * michael@0: *

michael@0: * This class should only be subclassed to implement variants of the Chinese lunar calendar.

michael@0: *

michael@0: * ChineseCalendar usually should be instantiated using michael@0: * {@link com.ibm.icu.util.Calendar#getInstance(ULocale)} passing in a ULocale michael@0: * with the tag "@calendar=chinese".

michael@0: * michael@0: * @see com.ibm.icu.text.ChineseDateFormat michael@0: * @see com.ibm.icu.util.Calendar michael@0: * @author Alan Liu michael@0: * @internal michael@0: */ michael@0: class U_I18N_API ChineseCalendar : public Calendar { michael@0: public: michael@0: //------------------------------------------------------------------------- michael@0: // Constructors... michael@0: //------------------------------------------------------------------------- michael@0: michael@0: /** michael@0: * Constructs a ChineseCalendar based on the current time in the default time zone michael@0: * with the given locale. michael@0: * michael@0: * @param aLocale The given locale. michael@0: * @param success Indicates the status of ChineseCalendar object construction. michael@0: * Returns U_ZERO_ERROR if constructed successfully. michael@0: * @internal michael@0: */ michael@0: ChineseCalendar(const Locale& aLocale, UErrorCode &success); michael@0: michael@0: protected: michael@0: michael@0: /** michael@0: * Constructs a ChineseCalendar based on the current time in the default time zone michael@0: * with the given locale, using the specified epoch year and time zone for michael@0: * astronomical calculations. michael@0: * michael@0: * @param aLocale The given locale. michael@0: * @param epochYear The epoch year to use for calculation. michael@0: * @param zoneAstroCalc The TimeZone to use for astronomical calculations. If null, michael@0: * will be set appropriately for Chinese calendar (UTC + 8:00). michael@0: * @param success Indicates the status of ChineseCalendar object construction; michael@0: * if successful, will not be changed to an error value. michael@0: * @internal michael@0: */ michael@0: ChineseCalendar(const Locale& aLocale, int32_t epochYear, const TimeZone* zoneAstroCalc, UErrorCode &success); michael@0: michael@0: public: michael@0: /** michael@0: * Copy Constructor michael@0: * @internal michael@0: */ michael@0: ChineseCalendar(const ChineseCalendar& other); michael@0: michael@0: /** michael@0: * Destructor. michael@0: * @internal michael@0: */ michael@0: virtual ~ChineseCalendar(); michael@0: michael@0: // clone michael@0: virtual Calendar* clone() const; michael@0: michael@0: private: michael@0: michael@0: //------------------------------------------------------------------------- michael@0: // Internal data.... michael@0: //------------------------------------------------------------------------- michael@0: michael@0: UBool isLeapYear; michael@0: int32_t fEpochYear; // Start year of this Chinese calendar instance. michael@0: const TimeZone* fZoneAstroCalc; // Zone used for the astronomical calculation michael@0: // of this Chinese calendar instance. michael@0: michael@0: //---------------------------------------------------------------------- michael@0: // Calendar framework michael@0: //---------------------------------------------------------------------- michael@0: michael@0: protected: michael@0: virtual int32_t handleGetLimit(UCalendarDateFields field, ELimitType limitType) const; michael@0: virtual int32_t handleGetMonthLength(int32_t extendedYear, int32_t month) const; michael@0: virtual int32_t handleComputeMonthStart(int32_t eyear, int32_t month, UBool useMonth) const; michael@0: virtual int32_t handleGetExtendedYear(); michael@0: virtual void handleComputeFields(int32_t julianDay, UErrorCode &status); michael@0: virtual const UFieldResolutionTable* getFieldResolutionTable() const; michael@0: michael@0: public: michael@0: virtual void add(UCalendarDateFields field, int32_t amount, UErrorCode &status); michael@0: virtual void add(EDateFields field, int32_t amount, UErrorCode &status); michael@0: virtual void roll(UCalendarDateFields field, int32_t amount, UErrorCode &status); michael@0: virtual void roll(EDateFields field, int32_t amount, UErrorCode &status); michael@0: michael@0: //---------------------------------------------------------------------- michael@0: // Internal methods & astronomical calculations michael@0: //---------------------------------------------------------------------- michael@0: michael@0: private: michael@0: michael@0: static const UFieldResolutionTable CHINESE_DATE_PRECEDENCE[]; michael@0: michael@0: double daysToMillis(double days) const; michael@0: double millisToDays(double millis) const; michael@0: virtual int32_t winterSolstice(int32_t gyear) const; michael@0: virtual int32_t newMoonNear(double days, UBool after) const; michael@0: virtual int32_t synodicMonthsBetween(int32_t day1, int32_t day2) const; michael@0: virtual int32_t majorSolarTerm(int32_t days) const; michael@0: virtual UBool hasNoMajorSolarTerm(int32_t newMoon) const; michael@0: virtual UBool isLeapMonthBetween(int32_t newMoon1, int32_t newMoon2) const; michael@0: virtual void computeChineseFields(int32_t days, int32_t gyear, michael@0: int32_t gmonth, UBool setAllFields); michael@0: virtual int32_t newYear(int32_t gyear) const; michael@0: virtual void offsetMonth(int32_t newMoon, int32_t dom, int32_t delta); michael@0: const TimeZone* getChineseCalZoneAstroCalc(void) const; michael@0: michael@0: // UObject stuff michael@0: public: michael@0: /** michael@0: * @return The class ID for this object. All objects of a given class have the michael@0: * same class ID. Objects of other classes have different class IDs. michael@0: * @internal michael@0: */ michael@0: virtual UClassID getDynamicClassID(void) const; michael@0: michael@0: /** michael@0: * Return the class ID for this class. This is useful only for comparing to a return michael@0: * value from getDynamicClassID(). For example: michael@0: * michael@0: * Base* polymorphic_pointer = createPolymorphicObject(); michael@0: * if (polymorphic_pointer->getDynamicClassID() == michael@0: * Derived::getStaticClassID()) ... michael@0: * michael@0: * @return The class ID for all objects of this class. michael@0: * @internal michael@0: */ michael@0: static UClassID U_EXPORT2 getStaticClassID(void); michael@0: michael@0: /** michael@0: * return the calendar type, "chinese". michael@0: * michael@0: * @return calendar type michael@0: * @internal michael@0: */ michael@0: virtual const char * getType() const; michael@0: michael@0: michael@0: protected: michael@0: /** michael@0: * (Overrides Calendar) Return true if the current date for this Calendar is in michael@0: * Daylight Savings Time. Recognizes DST_OFFSET, if it is set. michael@0: * michael@0: * @param status Fill-in parameter which receives the status of this operation. michael@0: * @return True if the current date for this Calendar is in Daylight Savings Time, michael@0: * false, otherwise. michael@0: * @internal michael@0: */ michael@0: virtual UBool inDaylightTime(UErrorCode& status) const; michael@0: michael@0: michael@0: /** michael@0: * Returns TRUE because the Islamic Calendar does have a default century michael@0: * @internal michael@0: */ michael@0: virtual UBool haveDefaultCentury() const; michael@0: michael@0: /** michael@0: * Returns the date of the start of the default century michael@0: * @return start of century - in milliseconds since epoch, 1970 michael@0: * @internal michael@0: */ michael@0: virtual UDate defaultCenturyStart() const; michael@0: michael@0: /** michael@0: * Returns the year in which the default century begins michael@0: * @internal michael@0: */ michael@0: virtual int32_t defaultCenturyStartYear() const; michael@0: michael@0: private: // default century stuff. michael@0: michael@0: /** michael@0: * Returns the beginning date of the 100-year window that dates michael@0: * with 2-digit years are considered to fall within. michael@0: */ michael@0: UDate internalGetDefaultCenturyStart(void) const; michael@0: michael@0: /** michael@0: * Returns the first year of the 100-year window that dates with michael@0: * 2-digit years are considered to fall within. michael@0: */ michael@0: int32_t internalGetDefaultCenturyStartYear(void) const; michael@0: michael@0: ChineseCalendar(); // default constructor not implemented michael@0: }; michael@0: michael@0: U_NAMESPACE_END michael@0: michael@0: #endif michael@0: #endif