Victor Chang | 7322950 | 2020-09-17 13:39:19 +0100 | [diff] [blame] | 1 | // © 2016 and later: Unicode, Inc. and others. |
| 2 | // License & terms of use: http://www.unicode.org/copyright.html |
| 3 | /* |
| 4 | ******************************************************************************** |
| 5 | * Copyright (C) 2003-2008, International Business Machines Corporation |
| 6 | * and others. All Rights Reserved. |
| 7 | ******************************************************************************** |
| 8 | * |
| 9 | * File JAPANCAL.H |
| 10 | * |
| 11 | * Modification History: |
| 12 | * |
| 13 | * Date Name Description |
| 14 | * 05/13/2003 srl copied from gregocal.h |
| 15 | ******************************************************************************** |
| 16 | */ |
| 17 | |
| 18 | #ifndef JAPANCAL_H |
| 19 | #define JAPANCAL_H |
| 20 | |
| 21 | #include "unicode/utypes.h" |
| 22 | |
| 23 | #if !UCONFIG_NO_FORMATTING |
| 24 | |
| 25 | #include "unicode/calendar.h" |
| 26 | #include "unicode/gregocal.h" |
| 27 | |
| 28 | U_NAMESPACE_BEGIN |
| 29 | |
| 30 | /** |
| 31 | * Concrete class which provides the Japanese calendar. |
| 32 | * <P> |
| 33 | * <code>JapaneseCalendar</code> is a subclass of <code>GregorianCalendar</code> |
| 34 | * that numbers years and eras based on the reigns of the Japanese emperors. |
| 35 | * The Japanese calendar is identical to the Gregorian calendar in all respects |
| 36 | * except for the year and era. The ascension of each emperor to the throne |
| 37 | * begins a new era, and the years of that era are numbered starting with the |
| 38 | * year of ascension as year 1. |
| 39 | * <p> |
| 40 | * Note that in the year of an imperial ascension, there are two possible sets |
| 41 | * of year and era values: that for the old era and for the new. For example, a |
| 42 | * new era began on January 7, 1989 AD. Strictly speaking, the first six days |
| 43 | * of that year were in the Showa era, e.g. "January 6, 64 Showa", while the rest |
| 44 | * of the year was in the Heisei era, e.g. "January 7, 1 Heisei". This class |
| 45 | * handles this distinction correctly when computing dates. However, in lenient |
| 46 | * mode either form of date is acceptable as input. |
| 47 | * <p> |
| 48 | * In modern times, eras have started on January 8, 1868 AD, Gregorian (Meiji), |
| 49 | * July 30, 1912 (Taisho), December 25, 1926 (Showa), and January 7, 1989 (Heisei). Constants |
| 50 | * for these eras, suitable for use in the <code>UCAL_ERA</code> field, are provided |
| 51 | * in this class. Note that the <em>number</em> used for each era is more or |
| 52 | * less arbitrary. Currently, the era starting in 645 AD is era #0; however this |
| 53 | * may change in the future. Use the predefined constants rather than using actual, |
| 54 | * absolute numbers. |
| 55 | * <p> |
| 56 | * Since ICU4C 63, start date of each era is imported from CLDR. CLDR era data |
| 57 | * may contain tentative era in near future with placeholder names. By default, |
| 58 | * such era data is not enabled. ICU4C users who want to test the behavior of |
| 59 | * the future era can enable this one of following settings (in the priority |
| 60 | * order): |
| 61 | * <ol> |
| 62 | * <li>Environment variable <code>ICU_ENABLE_TENTATIVE_ERA=true</code>.</li> |
| 63 | * </nl> |
| 64 | * @internal |
| 65 | */ |
| 66 | class JapaneseCalendar : public GregorianCalendar { |
| 67 | public: |
| 68 | |
| 69 | /** |
| 70 | * Check environment variable. |
| 71 | * @internal |
| 72 | */ |
| 73 | U_I18N_API static UBool U_EXPORT2 enableTentativeEra(void); |
| 74 | |
| 75 | /** |
| 76 | * Useful constants for JapaneseCalendar. |
| 77 | * Exported for use by test code. |
| 78 | * @internal |
| 79 | */ |
| 80 | U_I18N_API static uint32_t U_EXPORT2 getCurrentEra(void); // the current era |
| 81 | |
| 82 | /** |
| 83 | * Constructs a JapaneseCalendar based on the current time in the default time zone |
| 84 | * with the given locale. |
| 85 | * |
| 86 | * @param aLocale The given locale. |
| 87 | * @param success Indicates the status of JapaneseCalendar object construction. |
| 88 | * Returns U_ZERO_ERROR if constructed successfully. |
| 89 | * @stable ICU 2.0 |
| 90 | */ |
| 91 | JapaneseCalendar(const Locale& aLocale, UErrorCode& success); |
| 92 | |
| 93 | |
| 94 | /** |
| 95 | * Destructor |
| 96 | * @internal |
| 97 | */ |
| 98 | virtual ~JapaneseCalendar(); |
| 99 | |
| 100 | /** |
| 101 | * Copy constructor |
| 102 | * @param source the object to be copied. |
| 103 | * @internal |
| 104 | */ |
| 105 | JapaneseCalendar(const JapaneseCalendar& source); |
| 106 | |
| 107 | /** |
| 108 | * Default assignment operator |
| 109 | * @param right the object to be copied. |
| 110 | * @internal |
| 111 | */ |
| 112 | JapaneseCalendar& operator=(const JapaneseCalendar& right); |
| 113 | |
| 114 | /** |
| 115 | * Create and return a polymorphic copy of this calendar. |
| 116 | * @return return a polymorphic copy of this calendar. |
| 117 | * @internal |
| 118 | */ |
| 119 | virtual JapaneseCalendar* clone() const; |
| 120 | |
| 121 | /** |
| 122 | * Return the extended year defined by the current fields. In the |
| 123 | * Japanese calendar case, this is equal to the equivalent extended Gregorian year. |
| 124 | * @internal |
| 125 | */ |
| 126 | virtual int32_t handleGetExtendedYear(); |
| 127 | |
| 128 | /** |
| 129 | * Return the maximum value that this field could have, given the current date. |
| 130 | * @internal |
| 131 | */ |
| 132 | virtual int32_t getActualMaximum(UCalendarDateFields field, UErrorCode& status) const; |
| 133 | |
| 134 | |
| 135 | public: |
| 136 | /** |
| 137 | * Override Calendar Returns a unique class ID POLYMORPHICALLY. Pure virtual |
| 138 | * override. This method is to implement a simple version of RTTI, since not all C++ |
| 139 | * compilers support genuine RTTI. Polymorphic operator==() and clone() methods call |
| 140 | * this method. |
| 141 | * |
| 142 | * @return The class ID for this object. All objects of a given class have the |
| 143 | * same class ID. Objects of other classes have different class IDs. |
| 144 | * @internal |
| 145 | */ |
| 146 | virtual UClassID getDynamicClassID(void) const; |
| 147 | |
| 148 | /** |
| 149 | * Return the class ID for this class. This is useful only for comparing to a return |
| 150 | * value from getDynamicClassID(). For example: |
| 151 | * |
| 152 | * Base* polymorphic_pointer = createPolymorphicObject(); |
| 153 | * if (polymorphic_pointer->getDynamicClassID() == |
| 154 | * Derived::getStaticClassID()) ... |
| 155 | * |
| 156 | * @return The class ID for all objects of this class. |
| 157 | * @internal |
| 158 | */ |
| 159 | U_I18N_API static UClassID U_EXPORT2 getStaticClassID(void); |
| 160 | |
| 161 | /** |
| 162 | * return the calendar type, "japanese". |
| 163 | * |
| 164 | * @return calendar type |
| 165 | * @internal |
| 166 | */ |
| 167 | virtual const char * getType() const; |
| 168 | |
| 169 | /** |
Victor Chang | ce4bf3c | 2021-01-19 16:34:24 +0000 | [diff] [blame] | 170 | * @return false - no default century in Japanese |
Victor Chang | 7322950 | 2020-09-17 13:39:19 +0100 | [diff] [blame] | 171 | * @internal |
| 172 | */ |
| 173 | virtual UBool haveDefaultCentury() const; |
| 174 | |
| 175 | /** |
| 176 | * Not used - no default century. |
| 177 | * @internal |
| 178 | */ |
| 179 | virtual UDate defaultCenturyStart() const; |
| 180 | /** |
| 181 | * Not used - no default century. |
| 182 | * @internal |
| 183 | */ |
| 184 | virtual int32_t defaultCenturyStartYear() const; |
| 185 | |
| 186 | private: |
| 187 | JapaneseCalendar(); // default constructor not implemented |
| 188 | |
| 189 | protected: |
| 190 | /** |
| 191 | * Calculate the era for internal computation |
| 192 | * @internal |
| 193 | */ |
| 194 | virtual int32_t internalGetEra() const; |
| 195 | |
| 196 | /** |
| 197 | * Compute fields from the JD |
| 198 | * @internal |
| 199 | */ |
| 200 | virtual void handleComputeFields(int32_t julianDay, UErrorCode& status); |
| 201 | |
| 202 | /** |
| 203 | * Calculate the limit for a specified type of limit and field |
| 204 | * @internal |
| 205 | */ |
| 206 | virtual int32_t handleGetLimit(UCalendarDateFields field, ELimitType limitType) const; |
| 207 | |
| 208 | /*** |
| 209 | * Called by computeJulianDay. Returns the default month (0-based) for the year, |
| 210 | * taking year and era into account. Will return the first month of the given era, if |
| 211 | * the current year is an ascension year. |
| 212 | * @param eyear the extended year |
| 213 | * @internal |
| 214 | */ |
| 215 | virtual int32_t getDefaultMonthInYear(int32_t eyear); |
| 216 | |
| 217 | /*** |
| 218 | * Called by computeJulianDay. Returns the default day (1-based) for the month, |
| 219 | * taking currently-set year and era into account. Will return the first day of the given |
| 220 | * era, if the current month is an ascension year and month. |
| 221 | * @param eyear the extended year |
| 222 | * @param mon the month in the year |
| 223 | * @internal |
| 224 | */ |
| 225 | virtual int32_t getDefaultDayInMonth(int32_t eyear, int32_t month); |
| 226 | }; |
| 227 | |
| 228 | U_NAMESPACE_END |
| 229 | |
| 230 | #endif /* #if !UCONFIG_NO_FORMATTING */ |
| 231 | |
| 232 | #endif |
| 233 | //eof |
| 234 | |