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1 // Copyright (C) 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 1053 AD is era #0; however this
53  * may change in the future as we add more historical data.  Use the predefined
54  * constants rather than using actual, absolute numbers.
55  * <p>
56  * @internal
57  */
58 class JapaneseCalendar : public GregorianCalendar {
59 public:
60 
61     /**
62      * Useful constants for JapaneseCalendar.
63      * @internal
64      */
65     U_I18N_API static uint32_t U_EXPORT2 getCurrentEra(void); // the current era
66 
67     /**
68      * Constructs a JapaneseCalendar based on the current time in the default time zone
69      * with the given locale.
70      *
71      * @param aLocale  The given locale.
72      * @param success  Indicates the status of JapaneseCalendar object construction.
73      *                 Returns U_ZERO_ERROR if constructed successfully.
74      * @stable ICU 2.0
75      */
76     JapaneseCalendar(const Locale& aLocale, UErrorCode& success);
77 
78 
79     /**
80      * Destructor
81      * @internal
82      */
83     virtual ~JapaneseCalendar();
84 
85     /**
86      * Copy constructor
87      * @param source    the object to be copied.
88      * @internal
89      */
90     JapaneseCalendar(const JapaneseCalendar& source);
91 
92     /**
93      * Default assignment operator
94      * @param right    the object to be copied.
95      * @internal
96      */
97     JapaneseCalendar& operator=(const JapaneseCalendar& right);
98 
99     /**
100      * Create and return a polymorphic copy of this calendar.
101      * @return    return a polymorphic copy of this calendar.
102      * @internal
103      */
104     virtual Calendar* clone(void) const;
105 
106     /**
107      * Return the extended year defined by the current fields.  In the
108      * Japanese calendar case, this is equal to the equivalent extended Gregorian year.
109      * @internal
110      */
111     virtual int32_t handleGetExtendedYear();
112 
113     /**
114      * Return the maximum value that this field could have, given the current date.
115      * @internal
116      */
117     virtual int32_t getActualMaximum(UCalendarDateFields field, UErrorCode& status) const;
118 
119 
120 public:
121     /**
122      * Override Calendar Returns a unique class ID POLYMORPHICALLY. Pure virtual
123      * override. This method is to implement a simple version of RTTI, since not all C++
124      * compilers support genuine RTTI. Polymorphic operator==() and clone() methods call
125      * this method.
126      *
127      * @return   The class ID for this object. All objects of a given class have the
128      *           same class ID. Objects of other classes have different class IDs.
129      * @internal
130      */
131     virtual UClassID getDynamicClassID(void) const;
132 
133     /**
134      * Return the class ID for this class. This is useful only for comparing to a return
135      * value from getDynamicClassID(). For example:
136      *
137      *      Base* polymorphic_pointer = createPolymorphicObject();
138      *      if (polymorphic_pointer->getDynamicClassID() ==
139      *          Derived::getStaticClassID()) ...
140      *
141      * @return   The class ID for all objects of this class.
142      * @internal
143      */
144     U_I18N_API static UClassID U_EXPORT2 getStaticClassID(void);
145 
146     /**
147      * return the calendar type, "japanese".
148      *
149      * @return calendar type
150      * @internal
151      */
152     virtual const char * getType() const;
153 
154     /**
155      * @return FALSE - no default century in Japanese
156      * @internal
157      */
158     virtual UBool haveDefaultCentury() const;
159 
160     /**
161      * Not used - no default century.
162      * @internal
163      */
164     virtual UDate defaultCenturyStart() const;
165     /**
166      * Not used - no default century.
167      * @internal
168      */
169     virtual int32_t defaultCenturyStartYear() const;
170 
171 private:
172     JapaneseCalendar(); // default constructor not implemented
173 
174 protected:
175     /**
176      * Calculate the era for internal computation
177      * @internal
178      */
179     virtual int32_t internalGetEra() const;
180 
181     /**
182      * Compute fields from the JD
183      * @internal
184      */
185     virtual void handleComputeFields(int32_t julianDay, UErrorCode& status);
186 
187     /**
188      * Calculate the limit for a specified type of limit and field
189      * @internal
190      */
191     virtual int32_t handleGetLimit(UCalendarDateFields field, ELimitType limitType) const;
192 
193     /***
194      * Called by computeJulianDay.  Returns the default month (0-based) for the year,
195      * taking year and era into account.  Will return the first month of the given era, if
196      * the current year is an ascension year.
197      * @param eyear the extended year
198      * @internal
199      */
200     virtual int32_t getDefaultMonthInYear(int32_t eyear);
201 
202     /***
203      * Called by computeJulianDay.  Returns the default day (1-based) for the month,
204      * taking currently-set year and era into account.  Will return the first day of the given
205      * era, if the current month is an ascension year and month.
206      * @param eyear the extended year
207      * @param mon the month in the year
208      * @internal
209      */
210     virtual int32_t getDefaultDayInMonth(int32_t eyear, int32_t month);
211 };
212 
213 U_NAMESPACE_END
214 
215 #endif /* #if !UCONFIG_NO_FORMATTING */
216 
217 #endif
218 //eof
219 
220