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1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 ********************************************************************************
5 *   Copyright (C) 1997-2014, International Business Machines
6 *   Corporation and others.  All Rights Reserved.
7 ********************************************************************************
8 *
9 * File CALENDAR.H
10 *
11 * Modification History:
12 *
13 *   Date        Name        Description
14 *   04/22/97    aliu        Expanded and corrected comments and other header
15 *                           contents.
16 *   05/01/97    aliu        Made equals(), before(), after() arguments const.
17 *   05/20/97    aliu        Replaced fAreFieldsSet with fAreFieldsInSync and
18 *                           fAreAllFieldsSet.
19 *   07/27/98    stephen     Sync up with JDK 1.2
20 *   11/15/99    weiv        added YEAR_WOY and DOW_LOCAL
21 *                           to EDateFields
22 *    8/19/2002  srl         Removed Javaisms
23 *   11/07/2003  srl         Update, clean up documentation.
24 ********************************************************************************
25 */
26 
27 #ifndef CALENDAR_H
28 #define CALENDAR_H
29 
30 #include "unicode/utypes.h"
31 
32 #if U_SHOW_CPLUSPLUS_API
33 
34 /**
35  * \file
36  * \brief C++ API: Calendar object
37  */
38 #if !UCONFIG_NO_FORMATTING
39 
40 #include "unicode/uobject.h"
41 #include "unicode/locid.h"
42 #include "unicode/timezone.h"
43 #include "unicode/ucal.h"
44 #include "unicode/umisc.h"
45 
46 U_NAMESPACE_BEGIN
47 
48 class ICUServiceFactory;
49 
50 // Do not conditionalize the following with #ifndef U_HIDE_INTERNAL_API,
51 // it is a return type for a virtual method (@internal)
52 /**
53  * @internal
54  */
55 typedef int32_t UFieldResolutionTable[12][8];
56 
57 class BasicTimeZone;
58 /**
59  * `Calendar` is an abstract base class for converting between
60  * a `UDate` object and a set of integer fields such as
61  * `YEAR`, `MONTH`, `DAY`, `HOUR`, and so on.
62  * (A `UDate` object represents a specific instant in
63  * time with millisecond precision. See UDate
64  * for information about the `UDate` class.)
65  *
66  * Subclasses of `Calendar` interpret a `UDate`
67  * according to the rules of a specific calendar system.
68  * The most commonly used subclass of `Calendar` is
69  * `GregorianCalendar`. Other subclasses could represent
70  * the various types of lunar calendars in use in many parts of the world.
71  *
72  * **NOTE**: (ICU 2.6) The subclass interface should be considered unstable -
73  * it WILL change.
74  *
75  * Like other locale-sensitive classes, `Calendar` provides a
76  * static method, `createInstance`, for getting a generally useful
77  * object of this type. `Calendar`'s `createInstance` method
78  * returns the appropriate `Calendar` subclass whose
79  * time fields have been initialized with the current date and time:
80  *
81  *     Calendar *rightNow = Calendar::createInstance(errCode);
82  *
83  * A `Calendar` object can produce all the time field values
84  * needed to implement the date-time formatting for a particular language
85  * and calendar style (for example, Japanese-Gregorian, Japanese-Traditional).
86  *
87  * When computing a `UDate` from time fields, some special circumstances
88  * may arise: there may be insufficient information to compute the
89  * `UDate` (such as only year and month but no day in the month),
90  * there may be inconsistent information (such as "Tuesday, July 15, 1996"
91  * -- July 15, 1996 is actually a Monday), or the input time might be ambiguous
92  * because of time zone transition.
93  *
94  * **Insufficient information.** The calendar will use default
95  * information to specify the missing fields. This may vary by calendar; for
96  * the Gregorian calendar, the default for a field is the same as that of the
97  * start of the epoch: i.e., YEAR = 1970, MONTH = JANUARY, DATE = 1, etc.
98  *
99  * **Inconsistent information.** If fields conflict, the calendar
100  * will give preference to fields set more recently. For example, when
101  * determining the day, the calendar will look for one of the following
102  * combinations of fields.  The most recent combination, as determined by the
103  * most recently set single field, will be used.
104  *
105  *     MONTH + DAY_OF_MONTH
106  *     MONTH + WEEK_OF_MONTH + DAY_OF_WEEK
107  *     MONTH + DAY_OF_WEEK_IN_MONTH + DAY_OF_WEEK
108  *     DAY_OF_YEAR
109  *     DAY_OF_WEEK + WEEK_OF_YEAR
110  *
111  * For the time of day:
112  *
113  *     HOUR_OF_DAY
114  *     AM_PM + HOUR
115  *
116  * **Ambiguous Wall Clock Time.** When time offset from UTC has
117  * changed, it produces an ambiguous time slot around the transition. For example,
118  * many US locations observe daylight saving time. On the date switching to daylight
119  * saving time in US, wall clock time jumps from 12:59 AM (standard) to 2:00 AM
120  * (daylight). Therefore, wall clock time from 1:00 AM to 1:59 AM do not exist on
121  * the date. When the input wall time fall into this missing time slot, the ICU
122  * Calendar resolves the time using the UTC offset before the transition by default.
123  * In this example, 1:30 AM is interpreted as 1:30 AM standard time (non-exist),
124  * so the final result will be 2:30 AM daylight time.
125  *
126  * On the date switching back to standard time, wall clock time is moved back one
127  * hour at 2:00 AM. So wall clock time from 1:00 AM to 1:59 AM occur twice. In this
128  * case, the ICU Calendar resolves the time using the UTC offset after the transition
129  * by default. For example, 1:30 AM on the date is resolved as 1:30 AM standard time.
130  *
131  * Ambiguous wall clock time resolution behaviors can be customized by Calendar APIs
132  * {@link #setRepeatedWallTimeOption} and {@link #setSkippedWallTimeOption}.
133  * These methods are available in ICU 49 or later versions.
134  *
135  * **Note:** for some non-Gregorian calendars, different
136  * fields may be necessary for complete disambiguation. For example, a full
137  * specification of the historical Arabic astronomical calendar requires year,
138  * month, day-of-month *and* day-of-week in some cases.
139  *
140  * **Note:** There are certain possible ambiguities in
141  * interpretation of certain singular times, which are resolved in the
142  * following ways:
143  *
144  *   1. 24:00:00 "belongs" to the following day. That is,
145  *      23:59 on Dec 31, 1969 < 24:00 on Jan 1, 1970 < 24:01:00 on Jan 1, 1970
146  *   2. Although historically not precise, midnight also belongs to "am",
147  *      and noon belongs to "pm", so on the same day,
148  *      12:00 am (midnight) < 12:01 am, and 12:00 pm (noon) < 12:01 pm
149  *
150  * The date or time format strings are not part of the definition of a
151  * calendar, as those must be modifiable or overridable by the user at
152  * runtime. Use `DateFormat` to format dates.
153  *
154  * `Calendar` provides an API for field "rolling", where fields
155  * can be incremented or decremented, but wrap around. For example, rolling the
156  * month up in the date December 12, **1996** results in
157  * January 12, **1996**.
158  *
159  * `Calendar` also provides a date arithmetic function for
160  * adding the specified (signed) amount of time to a particular time field.
161  * For example, subtracting 5 days from the date `September 12, 1996`
162  * results in `September 7, 1996`.
163  *
164  * ***Supported range***
165  *
166  * The allowable range of `Calendar` has been narrowed. `GregorianCalendar` used
167  * to attempt to support the range of dates with millisecond values from
168  * `Long.MIN_VALUE` to `Long.MAX_VALUE`. The new `Calendar` protocol specifies the
169  * maximum range of supportable dates as those having Julian day numbers
170  * of `-0x7F000000` to `+0x7F000000`. This corresponds to years from ~5,800,000 BCE
171  * to ~5,800,000 CE. Programmers should use the protected constants in `Calendar` to
172  * specify an extremely early or extremely late date.
173  *
174  * <p>
175  * The Japanese calendar uses a combination of era name and year number.
176  * When an emperor of Japan abdicates and a new emperor ascends the throne,
177  * a new era is declared and year number is reset to 1. Even if the date of
178  * abdication is scheduled ahead of time, the new era name might not be
179  * announced until just before the date. In such case, ICU4C may include
180  * a start date of future era without actual era name, but not enabled
181  * by default. ICU4C users who want to test the behavior of the future era
182  * can enable the tentative era by:
183  * <ul>
184  * <li>Environment variable <code>ICU_ENABLE_TENTATIVE_ERA=true</code>.</li>
185  * </ul>
186  *
187  * @stable ICU 2.0
188  */
189 class U_I18N_API Calendar : public UObject {
190 public:
191 #ifndef U_FORCE_HIDE_DEPRECATED_API
192     /**
193      * Field IDs for date and time. Used to specify date/time fields. ERA is calendar
194      * specific. Example ranges given are for illustration only; see specific Calendar
195      * subclasses for actual ranges.
196      * @deprecated ICU 2.6. Use C enum UCalendarDateFields defined in ucal.h
197      */
198     enum EDateFields {
199 #ifndef U_HIDE_DEPRECATED_API
200 /*
201  * ERA may be defined on other platforms. To avoid any potential problems undefined it here.
202  */
203 #ifdef ERA
204 #undef ERA
205 #endif
206         ERA,                  // Example: 0..1
207         YEAR,                 // Example: 1..big number
208         MONTH,                // Example: 0..11
209         WEEK_OF_YEAR,         // Example: 1..53
210         WEEK_OF_MONTH,        // Example: 1..4
211         DATE,                 // Example: 1..31
212         DAY_OF_YEAR,          // Example: 1..365
213         DAY_OF_WEEK,          // Example: 1..7
214         DAY_OF_WEEK_IN_MONTH, // Example: 1..4, may be specified as -1
215         AM_PM,                // Example: 0..1
216         HOUR,                 // Example: 0..11
217         HOUR_OF_DAY,          // Example: 0..23
218         MINUTE,               // Example: 0..59
219         SECOND,               // Example: 0..59
220         MILLISECOND,          // Example: 0..999
221         ZONE_OFFSET,          // Example: -12*U_MILLIS_PER_HOUR..12*U_MILLIS_PER_HOUR
222         DST_OFFSET,           // Example: 0 or U_MILLIS_PER_HOUR
223         YEAR_WOY,             // 'Y' Example: 1..big number - Year of Week of Year
224         DOW_LOCAL,            // 'e' Example: 1..7 - Day of Week / Localized
225 
226         EXTENDED_YEAR,
227         JULIAN_DAY,
228         MILLISECONDS_IN_DAY,
229         IS_LEAP_MONTH,
230 
231         FIELD_COUNT = UCAL_FIELD_COUNT // See ucal.h for other fields.
232 #endif /* U_HIDE_DEPRECATED_API */
233     };
234 #endif  // U_FORCE_HIDE_DEPRECATED_API
235 
236 #ifndef U_HIDE_DEPRECATED_API
237     /**
238      * Useful constant for days of week. Note: Calendar day-of-week is 1-based. Clients
239      * who create locale resources for the field of first-day-of-week should be aware of
240      * this. For instance, in US locale, first-day-of-week is set to 1, i.e., SUNDAY.
241      * @deprecated ICU 2.6. Use C enum UCalendarDaysOfWeek defined in ucal.h
242      */
243     enum EDaysOfWeek {
244         SUNDAY = 1,
245         MONDAY,
246         TUESDAY,
247         WEDNESDAY,
248         THURSDAY,
249         FRIDAY,
250         SATURDAY
251     };
252 
253     /**
254      * Useful constants for month. Note: Calendar month is 0-based.
255      * @deprecated ICU 2.6. Use C enum UCalendarMonths defined in ucal.h
256      */
257     enum EMonths {
258         JANUARY,
259         FEBRUARY,
260         MARCH,
261         APRIL,
262         MAY,
263         JUNE,
264         JULY,
265         AUGUST,
266         SEPTEMBER,
267         OCTOBER,
268         NOVEMBER,
269         DECEMBER,
270         UNDECIMBER
271     };
272 
273     /**
274      * Useful constants for hour in 12-hour clock. Used in GregorianCalendar.
275      * @deprecated ICU 2.6. Use C enum UCalendarAMPMs defined in ucal.h
276      */
277     enum EAmpm {
278         AM,
279         PM
280     };
281 #endif  /* U_HIDE_DEPRECATED_API */
282 
283     /**
284      * destructor
285      * @stable ICU 2.0
286      */
287     virtual ~Calendar();
288 
289     /**
290      * Create and return a polymorphic copy of this calendar.
291      *
292      * @return    a polymorphic copy of this calendar.
293      * @stable ICU 2.0
294      */
295     virtual Calendar* clone() const = 0;
296 
297     /**
298      * Creates a Calendar using the default timezone and locale. Clients are responsible
299      * for deleting the object returned.
300      *
301      * @param success  Indicates the success/failure of Calendar creation. Filled in
302      *                 with U_ZERO_ERROR if created successfully, set to a failure result
303      *                 otherwise. U_MISSING_RESOURCE_ERROR will be returned if the resource data
304      *                 requests a calendar type which has not been installed.
305      * @return         A Calendar if created successfully. NULL otherwise.
306      * @stable ICU 2.0
307      */
308     static Calendar* U_EXPORT2 createInstance(UErrorCode& success);
309 
310     /**
311      * Creates a Calendar using the given timezone and the default locale.
312      * The Calendar takes ownership of zoneToAdopt; the
313      * client must not delete it.
314      *
315      * @param zoneToAdopt  The given timezone to be adopted.
316      * @param success      Indicates the success/failure of Calendar creation. Filled in
317      *                     with U_ZERO_ERROR if created successfully, set to a failure result
318      *                     otherwise.
319      * @return             A Calendar if created successfully. NULL otherwise.
320      * @stable ICU 2.0
321      */
322     static Calendar* U_EXPORT2 createInstance(TimeZone* zoneToAdopt, UErrorCode& success);
323 
324     /**
325      * Creates a Calendar using the given timezone and the default locale.  The TimeZone
326      * is _not_ adopted; the client is still responsible for deleting it.
327      *
328      * @param zone  The timezone.
329      * @param success      Indicates the success/failure of Calendar creation. Filled in
330      *                     with U_ZERO_ERROR if created successfully, set to a failure result
331      *                     otherwise.
332      * @return             A Calendar if created successfully. NULL otherwise.
333      * @stable ICU 2.0
334      */
335     static Calendar* U_EXPORT2 createInstance(const TimeZone& zone, UErrorCode& success);
336 
337     /**
338      * Creates a Calendar using the default timezone and the given locale.
339      *
340      * @param aLocale  The given locale.
341      * @param success  Indicates the success/failure of Calendar creation. Filled in
342      *                 with U_ZERO_ERROR if created successfully, set to a failure result
343      *                 otherwise.
344      * @return         A Calendar if created successfully. NULL otherwise.
345      * @stable ICU 2.0
346      */
347     static Calendar* U_EXPORT2 createInstance(const Locale& aLocale, UErrorCode& success);
348 
349     /**
350      * Creates a Calendar using the given timezone and given locale.
351      * The Calendar takes ownership of zoneToAdopt; the
352      * client must not delete it.
353      *
354      * @param zoneToAdopt  The given timezone to be adopted.
355      * @param aLocale      The given locale.
356      * @param success      Indicates the success/failure of Calendar creation. Filled in
357      *                     with U_ZERO_ERROR if created successfully, set to a failure result
358      *                     otherwise.
359      * @return             A Calendar if created successfully. NULL otherwise.
360      * @stable ICU 2.0
361      */
362     static Calendar* U_EXPORT2 createInstance(TimeZone* zoneToAdopt, const Locale& aLocale, UErrorCode& success);
363 
364     /**
365      * Gets a Calendar using the given timezone and given locale.  The TimeZone
366      * is _not_ adopted; the client is still responsible for deleting it.
367      *
368      * @param zone         The given timezone.
369      * @param aLocale      The given locale.
370      * @param success      Indicates the success/failure of Calendar creation. Filled in
371      *                     with U_ZERO_ERROR if created successfully, set to a failure result
372      *                     otherwise.
373      * @return             A Calendar if created successfully. NULL otherwise.
374      * @stable ICU 2.0
375      */
376     static Calendar* U_EXPORT2 createInstance(const TimeZone& zone, const Locale& aLocale, UErrorCode& success);
377 
378     /**
379      * Returns a list of the locales for which Calendars are installed.
380      *
381      * @param count  Number of locales returned.
382      * @return       An array of Locale objects representing the set of locales for which
383      *               Calendars are installed.  The system retains ownership of this list;
384      *               the caller must NOT delete it. Does not include user-registered Calendars.
385      * @stable ICU 2.0
386      */
387     static const Locale* U_EXPORT2 getAvailableLocales(int32_t& count);
388 
389 
390     /**
391      * Given a key and a locale, returns an array of string values in a preferred
392      * order that would make a difference. These are all and only those values where
393      * the open (creation) of the service with the locale formed from the input locale
394      * plus input keyword and that value has different behavior than creation with the
395      * input locale alone.
396      * @param key           one of the keys supported by this service.  For now, only
397      *                      "calendar" is supported.
398      * @param locale        the locale
399      * @param commonlyUsed  if set to true it will return only commonly used values
400      *                      with the given locale in preferred order.  Otherwise,
401      *                      it will return all the available values for the locale.
402      * @param status        ICU Error Code
403      * @return a string enumeration over keyword values for the given key and the locale.
404      * @stable ICU 4.2
405      */
406     static StringEnumeration* U_EXPORT2 getKeywordValuesForLocale(const char* key,
407                     const Locale& locale, UBool commonlyUsed, UErrorCode& status);
408 
409     /**
410      * Returns the current UTC (GMT) time measured in milliseconds since 0:00:00 on 1/1/70
411      * (derived from the system time).
412      *
413      * @return   The current UTC time in milliseconds.
414      * @stable ICU 2.0
415      */
416     static UDate U_EXPORT2 getNow(void);
417 
418     /**
419      * Gets this Calendar's time as milliseconds. May involve recalculation of time due
420      * to previous calls to set time field values. The time specified is non-local UTC
421      * (GMT) time. Although this method is const, this object may actually be changed
422      * (semantically const).
423      *
424      * @param status  Output param set to success/failure code on exit. If any value
425      *                previously set in the time field is invalid or restricted by
426      *                leniency, this will be set to an error status.
427      * @return        The current time in UTC (GMT) time, or zero if the operation
428      *                failed.
429      * @stable ICU 2.0
430      */
getTime(UErrorCode & status)431     inline UDate getTime(UErrorCode& status) const { return getTimeInMillis(status); }
432 
433     /**
434      * Sets this Calendar's current time with the given UDate. The time specified should
435      * be in non-local UTC (GMT) time.
436      *
437      * @param date  The given UDate in UTC (GMT) time.
438      * @param status  Output param set to success/failure code on exit. If any value
439      *                set in the time field is invalid or restricted by
440      *                leniency, this will be set to an error status.
441      * @stable ICU 2.0
442      */
setTime(UDate date,UErrorCode & status)443     inline void setTime(UDate date, UErrorCode& status) { setTimeInMillis(date, status); }
444 
445     /**
446      * Compares the equality of two Calendar objects. Objects of different subclasses
447      * are considered unequal. This comparison is very exacting; two Calendar objects
448      * must be in exactly the same state to be considered equal. To compare based on the
449      * represented time, use equals() instead.
450      *
451      * @param that  The Calendar object to be compared with.
452      * @return      true if the given Calendar is the same as this Calendar; false
453      *              otherwise.
454      * @stable ICU 2.0
455      */
456     virtual bool operator==(const Calendar& that) const;
457 
458     /**
459      * Compares the inequality of two Calendar objects.
460      *
461      * @param that  The Calendar object to be compared with.
462      * @return      true if the given Calendar is not the same as this Calendar; false
463      *              otherwise.
464      * @stable ICU 2.0
465      */
466     bool operator!=(const Calendar& that) const {return !operator==(that);}
467 
468     /**
469      * Returns true if the given Calendar object is equivalent to this
470      * one.  An equivalent Calendar will behave exactly as this one
471      * does, but it may be set to a different time.  By contrast, for
472      * the operator==() method to return true, the other Calendar must
473      * be set to the same time.
474      *
475      * @param other the Calendar to be compared with this Calendar
476      * @stable ICU 2.4
477      */
478     virtual UBool isEquivalentTo(const Calendar& other) const;
479 
480     /**
481      * Compares the Calendar time, whereas Calendar::operator== compares the equality of
482      * Calendar objects.
483      *
484      * @param when    The Calendar to be compared with this Calendar. Although this is a
485      *                const parameter, the object may be modified physically
486      *                (semantically const).
487      * @param status  Output param set to success/failure code on exit. If any value
488      *                previously set in the time field is invalid or restricted by
489      *                leniency, this will be set to an error status.
490      * @return        True if the current time of this Calendar is equal to the time of
491      *                Calendar when; false otherwise.
492      * @stable ICU 2.0
493      */
494     UBool equals(const Calendar& when, UErrorCode& status) const;
495 
496     /**
497      * Returns true if this Calendar's current time is before "when"'s current time.
498      *
499      * @param when    The Calendar to be compared with this Calendar. Although this is a
500      *                const parameter, the object may be modified physically
501      *                (semantically const).
502      * @param status  Output param set to success/failure code on exit. If any value
503      *                previously set in the time field is invalid or restricted by
504      *                leniency, this will be set to an error status.
505      * @return        True if the current time of this Calendar is before the time of
506      *                Calendar when; false otherwise.
507      * @stable ICU 2.0
508      */
509     UBool before(const Calendar& when, UErrorCode& status) const;
510 
511     /**
512      * Returns true if this Calendar's current time is after "when"'s current time.
513      *
514      * @param when    The Calendar to be compared with this Calendar. Although this is a
515      *                const parameter, the object may be modified physically
516      *                (semantically const).
517      * @param status  Output param set to success/failure code on exit. If any value
518      *                previously set in the time field is invalid or restricted by
519      *                leniency, this will be set to an error status.
520      * @return        True if the current time of this Calendar is after the time of
521      *                Calendar when; false otherwise.
522      * @stable ICU 2.0
523      */
524     UBool after(const Calendar& when, UErrorCode& status) const;
525 
526 #ifndef U_FORCE_HIDE_DEPRECATED_API
527     /**
528      * UDate Arithmetic function. Adds the specified (signed) amount of time to the given
529      * time field, based on the calendar's rules. For example, to subtract 5 days from
530      * the current time of the calendar, call add(Calendar::DATE, -5). When adding on
531      * the month or Calendar::MONTH field, other fields like date might conflict and
532      * need to be changed. For instance, adding 1 month on the date 01/31/96 will result
533      * in 02/29/96.
534      * Adding a positive value always means moving forward in time, so for the Gregorian calendar,
535      * starting with 100 BC and adding +1 to year results in 99 BC (even though this actually reduces
536      * the numeric value of the field itself).
537      *
538      * @param field   Specifies which date field to modify.
539      * @param amount  The amount of time to be added to the field, in the natural unit
540      *                for that field (e.g., days for the day fields, hours for the hour
541      *                field.)
542      * @param status  Output param set to success/failure code on exit. If any value
543      *                previously set in the time field is invalid or restricted by
544      *                leniency, this will be set to an error status.
545      * @deprecated ICU 2.6. use add(UCalendarDateFields field, int32_t amount, UErrorCode& status) instead.
546      */
547     virtual void add(EDateFields field, int32_t amount, UErrorCode& status);
548 #endif  // U_FORCE_HIDE_DEPRECATED_API
549 
550     /**
551      * UDate Arithmetic function. Adds the specified (signed) amount of time to the given
552      * time field, based on the calendar's rules. For example, to subtract 5 days from
553      * the current time of the calendar, call add(Calendar::DATE, -5). When adding on
554      * the month or Calendar::MONTH field, other fields like date might conflict and
555      * need to be changed. For instance, adding 1 month on the date 01/31/96 will result
556      * in 02/29/96.
557      * Adding a positive value always means moving forward in time, so for the Gregorian calendar,
558      * starting with 100 BC and adding +1 to year results in 99 BC (even though this actually reduces
559      * the numeric value of the field itself).
560      *
561      * @param field   Specifies which date field to modify.
562      * @param amount  The amount of time to be added to the field, in the natural unit
563      *                for that field (e.g., days for the day fields, hours for the hour
564      *                field.)
565      * @param status  Output param set to success/failure code on exit. If any value
566      *                previously set in the time field is invalid or restricted by
567      *                leniency, this will be set to an error status.
568      * @stable ICU 2.6.
569      */
570     virtual void add(UCalendarDateFields field, int32_t amount, UErrorCode& status);
571 
572 #ifndef U_HIDE_DEPRECATED_API
573     /**
574      * Time Field Rolling function. Rolls (up/down) a single unit of time on the given
575      * time field. For example, to roll the current date up by one day, call
576      * roll(Calendar::DATE, true). When rolling on the year or Calendar::YEAR field, it
577      * will roll the year value in the range between getMinimum(Calendar::YEAR) and the
578      * value returned by getMaximum(Calendar::YEAR). When rolling on the month or
579      * Calendar::MONTH field, other fields like date might conflict and, need to be
580      * changed. For instance, rolling the month up on the date 01/31/96 will result in
581      * 02/29/96. Rolling up always means rolling forward in time (unless the limit of the
582      * field is reached, in which case it may pin or wrap), so for Gregorian calendar,
583      * starting with 100 BC and rolling the year up results in 99 BC.
584      * When eras have a definite beginning and end (as in the Chinese calendar, or as in
585      * most eras in the Japanese calendar) then rolling the year past either limit of the
586      * era will cause the year to wrap around. When eras only have a limit at one end,
587      * then attempting to roll the year past that limit will result in pinning the year
588      * at that limit. Note that for most calendars in which era 0 years move forward in
589      * time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to
590      * result in negative years for era 0 (that is the only way to represent years before
591      * the calendar epoch).
592      * When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the
593      * hour value in the range between 0 and 23, which is zero-based.
594      * <P>
595      * NOTE: Do not use this method -- use roll(EDateFields, int, UErrorCode&) instead.
596      *
597      * @param field   The time field.
598      * @param up      Indicates if the value of the specified time field is to be rolled
599      *                up or rolled down. Use true if rolling up, false otherwise.
600      * @param status  Output param set to success/failure code on exit. If any value
601      *                previously set in the time field is invalid or restricted by
602      *                leniency, this will be set to an error status.
603      * @deprecated ICU 2.6. Use roll(UCalendarDateFields field, UBool up, UErrorCode& status) instead.
604      */
605     inline void roll(EDateFields field, UBool up, UErrorCode& status);
606 #endif  /* U_HIDE_DEPRECATED_API */
607 
608     /**
609      * Time Field Rolling function. Rolls (up/down) a single unit of time on the given
610      * time field. For example, to roll the current date up by one day, call
611      * roll(Calendar::DATE, true). When rolling on the year or Calendar::YEAR field, it
612      * will roll the year value in the range between getMinimum(Calendar::YEAR) and the
613      * value returned by getMaximum(Calendar::YEAR). When rolling on the month or
614      * Calendar::MONTH field, other fields like date might conflict and, need to be
615      * changed. For instance, rolling the month up on the date 01/31/96 will result in
616      * 02/29/96. Rolling up always means rolling forward in time (unless the limit of the
617      * field is reached, in which case it may pin or wrap), so for Gregorian calendar,
618      * starting with 100 BC and rolling the year up results in 99 BC.
619      * When eras have a definite beginning and end (as in the Chinese calendar, or as in
620      * most eras in the Japanese calendar) then rolling the year past either limit of the
621      * era will cause the year to wrap around. When eras only have a limit at one end,
622      * then attempting to roll the year past that limit will result in pinning the year
623      * at that limit. Note that for most calendars in which era 0 years move forward in
624      * time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to
625      * result in negative years for era 0 (that is the only way to represent years before
626      * the calendar epoch).
627      * When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the
628      * hour value in the range between 0 and 23, which is zero-based.
629      * <P>
630      * NOTE: Do not use this method -- use roll(UCalendarDateFields, int, UErrorCode&) instead.
631      *
632      * @param field   The time field.
633      * @param up      Indicates if the value of the specified time field is to be rolled
634      *                up or rolled down. Use true if rolling up, false otherwise.
635      * @param status  Output param set to success/failure code on exit. If any value
636      *                previously set in the time field is invalid or restricted by
637      *                leniency, this will be set to an error status.
638      * @stable ICU 2.6.
639      */
640     inline void roll(UCalendarDateFields field, UBool up, UErrorCode& status);
641 
642 #ifndef U_FORCE_HIDE_DEPRECATED_API
643     /**
644      * Time Field Rolling function. Rolls by the given amount on the given
645      * time field. For example, to roll the current date up by one day, call
646      * roll(Calendar::DATE, +1, status). When rolling on the month or
647      * Calendar::MONTH field, other fields like date might conflict and, need to be
648      * changed. For instance, rolling the month up on the date 01/31/96 will result in
649      * 02/29/96. Rolling by a positive value always means rolling forward in time (unless
650      * the limit of the field is reached, in which case it may pin or wrap), so for
651      * Gregorian calendar, starting with 100 BC and rolling the year by + 1 results in 99 BC.
652      * When eras have a definite beginning and end (as in the Chinese calendar, or as in
653      * most eras in the Japanese calendar) then rolling the year past either limit of the
654      * era will cause the year to wrap around. When eras only have a limit at one end,
655      * then attempting to roll the year past that limit will result in pinning the year
656      * at that limit. Note that for most calendars in which era 0 years move forward in
657      * time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to
658      * result in negative years for era 0 (that is the only way to represent years before
659      * the calendar epoch).
660      * When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the
661      * hour value in the range between 0 and 23, which is zero-based.
662      * <P>
663      * The only difference between roll() and add() is that roll() does not change
664      * the value of more significant fields when it reaches the minimum or maximum
665      * of its range, whereas add() does.
666      *
667      * @param field   The time field.
668      * @param amount  Indicates amount to roll.
669      * @param status  Output param set to success/failure code on exit. If any value
670      *                previously set in the time field is invalid, this will be set to
671      *                an error status.
672      * @deprecated ICU 2.6. Use roll(UCalendarDateFields field, int32_t amount, UErrorCode& status) instead.
673      */
674     virtual void roll(EDateFields field, int32_t amount, UErrorCode& status);
675 #endif  // U_FORCE_HIDE_DEPRECATED_API
676 
677     /**
678      * Time Field Rolling function. Rolls by the given amount on the given
679      * time field. For example, to roll the current date up by one day, call
680      * roll(Calendar::DATE, +1, status). When rolling on the month or
681      * Calendar::MONTH field, other fields like date might conflict and, need to be
682      * changed. For instance, rolling the month up on the date 01/31/96 will result in
683      * 02/29/96. Rolling by a positive value always means rolling forward in time (unless
684      * the limit of the field is reached, in which case it may pin or wrap), so for
685      * Gregorian calendar, starting with 100 BC and rolling the year by + 1 results in 99 BC.
686      * When eras have a definite beginning and end (as in the Chinese calendar, or as in
687      * most eras in the Japanese calendar) then rolling the year past either limit of the
688      * era will cause the year to wrap around. When eras only have a limit at one end,
689      * then attempting to roll the year past that limit will result in pinning the year
690      * at that limit. Note that for most calendars in which era 0 years move forward in
691      * time (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to
692      * result in negative years for era 0 (that is the only way to represent years before
693      * the calendar epoch).
694      * When rolling on the hour-in-day or Calendar::HOUR_OF_DAY field, it will roll the
695      * hour value in the range between 0 and 23, which is zero-based.
696      * <P>
697      * The only difference between roll() and add() is that roll() does not change
698      * the value of more significant fields when it reaches the minimum or maximum
699      * of its range, whereas add() does.
700      *
701      * @param field   The time field.
702      * @param amount  Indicates amount to roll.
703      * @param status  Output param set to success/failure code on exit. If any value
704      *                previously set in the time field is invalid, this will be set to
705      *                an error status.
706      * @stable ICU 2.6.
707      */
708     virtual void roll(UCalendarDateFields field, int32_t amount, UErrorCode& status);
709 
710 #ifndef U_FORCE_HIDE_DEPRECATED_API
711     /**
712      * Return the difference between the given time and the time this
713      * calendar object is set to.  If this calendar is set
714      * <em>before</em> the given time, the returned value will be
715      * positive.  If this calendar is set <em>after</em> the given
716      * time, the returned value will be negative.  The
717      * <code>field</code> parameter specifies the units of the return
718      * value.  For example, if <code>fieldDifference(when,
719      * Calendar::MONTH)</code> returns 3, then this calendar is set to
720      * 3 months before <code>when</code>, and possibly some addition
721      * time less than one month.
722      *
723      * <p>As a side effect of this call, this calendar is advanced
724      * toward <code>when</code> by the given amount.  That is, calling
725      * this method has the side effect of calling <code>add(field,
726      * n)</code>, where <code>n</code> is the return value.
727      *
728      * <p>Usage: To use this method, call it first with the largest
729      * field of interest, then with progressively smaller fields.  For
730      * example:
731      *
732      * <pre>
733      * int y = cal->fieldDifference(when, Calendar::YEAR, err);
734      * int m = cal->fieldDifference(when, Calendar::MONTH, err);
735      * int d = cal->fieldDifference(when, Calendar::DATE, err);</pre>
736      *
737      * computes the difference between <code>cal</code> and
738      * <code>when</code> in years, months, and days.
739      *
740      * <p>Note: <code>fieldDifference()</code> is
741      * <em>asymmetrical</em>.  That is, in the following code:
742      *
743      * <pre>
744      * cal->setTime(date1, err);
745      * int m1 = cal->fieldDifference(date2, Calendar::MONTH, err);
746      * int d1 = cal->fieldDifference(date2, Calendar::DATE, err);
747      * cal->setTime(date2, err);
748      * int m2 = cal->fieldDifference(date1, Calendar::MONTH, err);
749      * int d2 = cal->fieldDifference(date1, Calendar::DATE, err);</pre>
750      *
751      * one might expect that <code>m1 == -m2 && d1 == -d2</code>.
752      * However, this is not generally the case, because of
753      * irregularities in the underlying calendar system (e.g., the
754      * Gregorian calendar has a varying number of days per month).
755      *
756      * @param when the date to compare this calendar's time to
757      * @param field the field in which to compute the result
758      * @param status  Output param set to success/failure code on exit. If any value
759      *                previously set in the time field is invalid, this will be set to
760      *                an error status.
761      * @return the difference, either positive or negative, between
762      * this calendar's time and <code>when</code>, in terms of
763      * <code>field</code>.
764      * @deprecated ICU 2.6. Use fieldDifference(UDate when, UCalendarDateFields field, UErrorCode& status).
765      */
766     virtual int32_t fieldDifference(UDate when, EDateFields field, UErrorCode& status);
767 #endif  // U_FORCE_HIDE_DEPRECATED_API
768 
769     /**
770      * Return the difference between the given time and the time this
771      * calendar object is set to.  If this calendar is set
772      * <em>before</em> the given time, the returned value will be
773      * positive.  If this calendar is set <em>after</em> the given
774      * time, the returned value will be negative.  The
775      * <code>field</code> parameter specifies the units of the return
776      * value.  For example, if <code>fieldDifference(when,
777      * Calendar::MONTH)</code> returns 3, then this calendar is set to
778      * 3 months before <code>when</code>, and possibly some addition
779      * time less than one month.
780      *
781      * <p>As a side effect of this call, this calendar is advanced
782      * toward <code>when</code> by the given amount.  That is, calling
783      * this method has the side effect of calling <code>add(field,
784      * n)</code>, where <code>n</code> is the return value.
785      *
786      * <p>Usage: To use this method, call it first with the largest
787      * field of interest, then with progressively smaller fields.  For
788      * example:
789      *
790      * <pre>
791      * int y = cal->fieldDifference(when, Calendar::YEAR, err);
792      * int m = cal->fieldDifference(when, Calendar::MONTH, err);
793      * int d = cal->fieldDifference(when, Calendar::DATE, err);</pre>
794      *
795      * computes the difference between <code>cal</code> and
796      * <code>when</code> in years, months, and days.
797      *
798      * <p>Note: <code>fieldDifference()</code> is
799      * <em>asymmetrical</em>.  That is, in the following code:
800      *
801      * <pre>
802      * cal->setTime(date1, err);
803      * int m1 = cal->fieldDifference(date2, Calendar::MONTH, err);
804      * int d1 = cal->fieldDifference(date2, Calendar::DATE, err);
805      * cal->setTime(date2, err);
806      * int m2 = cal->fieldDifference(date1, Calendar::MONTH, err);
807      * int d2 = cal->fieldDifference(date1, Calendar::DATE, err);</pre>
808      *
809      * one might expect that <code>m1 == -m2 && d1 == -d2</code>.
810      * However, this is not generally the case, because of
811      * irregularities in the underlying calendar system (e.g., the
812      * Gregorian calendar has a varying number of days per month).
813      *
814      * @param when the date to compare this calendar's time to
815      * @param field the field in which to compute the result
816      * @param status  Output param set to success/failure code on exit. If any value
817      *                previously set in the time field is invalid, this will be set to
818      *                an error status.
819      * @return the difference, either positive or negative, between
820      * this calendar's time and <code>when</code>, in terms of
821      * <code>field</code>.
822      * @stable ICU 2.6.
823      */
824     virtual int32_t fieldDifference(UDate when, UCalendarDateFields field, UErrorCode& status);
825 
826     /**
827      * Sets the calendar's time zone to be the one passed in. The Calendar takes ownership
828      * of the TimeZone; the caller is no longer responsible for deleting it.  If the
829      * given time zone is NULL, this function has no effect.
830      *
831      * @param value  The given time zone.
832      * @stable ICU 2.0
833      */
834     void adoptTimeZone(TimeZone* value);
835 
836     /**
837      * Sets the calendar's time zone to be the same as the one passed in. The TimeZone
838      * passed in is _not_ adopted; the client is still responsible for deleting it.
839      *
840      * @param zone  The given time zone.
841      * @stable ICU 2.0
842      */
843     void setTimeZone(const TimeZone& zone);
844 
845     /**
846      * Returns a reference to the time zone owned by this calendar. The returned reference
847      * is only valid until clients make another call to adoptTimeZone or setTimeZone,
848      * or this Calendar is destroyed.
849      *
850      * @return   The time zone object associated with this calendar.
851      * @stable ICU 2.0
852      */
853     const TimeZone& getTimeZone(void) const;
854 
855     /**
856      * Returns the time zone owned by this calendar. The caller owns the returned object
857      * and must delete it when done.  After this call, the new time zone associated
858      * with this Calendar is the default TimeZone as returned by TimeZone::createDefault().
859      *
860      * @return   The time zone object which was associated with this calendar.
861      * @stable ICU 2.0
862      */
863     TimeZone* orphanTimeZone(void);
864 
865     /**
866      * Queries if the current date for this Calendar is in Daylight Savings Time.
867      *
868      * @param status Fill-in parameter which receives the status of this operation.
869      * @return   True if the current date for this Calendar is in Daylight Savings Time,
870      *           false, otherwise.
871      * @stable ICU 2.0
872      */
873     virtual UBool inDaylightTime(UErrorCode& status) const = 0;
874 
875     /**
876      * Specifies whether or not date/time interpretation is to be lenient. With lenient
877      * interpretation, a date such as "February 942, 1996" will be treated as being
878      * equivalent to the 941st day after February 1, 1996. With strict interpretation,
879      * such dates will cause an error when computing time from the time field values
880      * representing the dates.
881      *
882      * @param lenient  True specifies date/time interpretation to be lenient.
883      *
884      * @see            DateFormat#setLenient
885      * @stable ICU 2.0
886      */
887     void setLenient(UBool lenient);
888 
889     /**
890      * Tells whether date/time interpretation is to be lenient.
891      *
892      * @return   True tells that date/time interpretation is to be lenient.
893      * @stable ICU 2.0
894      */
895     UBool isLenient(void) const;
896 
897     /**
898      * Sets the behavior for handling wall time repeating multiple times
899      * at negative time zone offset transitions. For example, 1:30 AM on
900      * November 6, 2011 in US Eastern time (America/New_York) occurs twice;
901      * 1:30 AM EDT, then 1:30 AM EST one hour later. When <code>UCAL_WALLTIME_FIRST</code>
902      * is used, the wall time 1:30AM in this example will be interpreted as 1:30 AM EDT
903      * (first occurrence). When <code>UCAL_WALLTIME_LAST</code> is used, it will be
904      * interpreted as 1:30 AM EST (last occurrence). The default value is
905      * <code>UCAL_WALLTIME_LAST</code>.
906      * <p>
907      * <b>Note:</b>When <code>UCAL_WALLTIME_NEXT_VALID</code> is not a valid
908      * option for this. When the argument is neither <code>UCAL_WALLTIME_FIRST</code>
909      * nor <code>UCAL_WALLTIME_LAST</code>, this method has no effect and will keep
910      * the current setting.
911      *
912      * @param option the behavior for handling repeating wall time, either
913      * <code>UCAL_WALLTIME_FIRST</code> or <code>UCAL_WALLTIME_LAST</code>.
914      * @see #getRepeatedWallTimeOption
915      * @stable ICU 49
916      */
917     void setRepeatedWallTimeOption(UCalendarWallTimeOption option);
918 
919     /**
920      * Gets the behavior for handling wall time repeating multiple times
921      * at negative time zone offset transitions.
922      *
923      * @return the behavior for handling repeating wall time, either
924      * <code>UCAL_WALLTIME_FIRST</code> or <code>UCAL_WALLTIME_LAST</code>.
925      * @see #setRepeatedWallTimeOption
926      * @stable ICU 49
927      */
928     UCalendarWallTimeOption getRepeatedWallTimeOption(void) const;
929 
930     /**
931      * Sets the behavior for handling skipped wall time at positive time zone offset
932      * transitions. For example, 2:30 AM on March 13, 2011 in US Eastern time (America/New_York)
933      * does not exist because the wall time jump from 1:59 AM EST to 3:00 AM EDT. When
934      * <code>UCAL_WALLTIME_FIRST</code> is used, 2:30 AM is interpreted as 30 minutes before 3:00 AM
935      * EDT, therefore, it will be resolved as 1:30 AM EST. When <code>UCAL_WALLTIME_LAST</code>
936      * is used, 2:30 AM is interpreted as 31 minutes after 1:59 AM EST, therefore, it will be
937      * resolved as 3:30 AM EDT. When <code>UCAL_WALLTIME_NEXT_VALID</code> is used, 2:30 AM will
938      * be resolved as next valid wall time, that is 3:00 AM EDT. The default value is
939      * <code>UCAL_WALLTIME_LAST</code>.
940      * <p>
941      * <b>Note:</b>This option is effective only when this calendar is lenient.
942      * When the calendar is strict, such non-existing wall time will cause an error.
943      *
944      * @param option the behavior for handling skipped wall time at positive time zone
945      * offset transitions, one of <code>UCAL_WALLTIME_FIRST</code>, <code>UCAL_WALLTIME_LAST</code> and
946      * <code>UCAL_WALLTIME_NEXT_VALID</code>.
947      * @see #getSkippedWallTimeOption
948      *
949      * @stable ICU 49
950      */
951     void setSkippedWallTimeOption(UCalendarWallTimeOption option);
952 
953     /**
954      * Gets the behavior for handling skipped wall time at positive time zone offset
955      * transitions.
956      *
957      * @return the behavior for handling skipped wall time, one of
958      * <code>UCAL_WALLTIME_FIRST</code>, <code>UCAL_WALLTIME_LAST</code>
959      * and <code>UCAL_WALLTIME_NEXT_VALID</code>.
960      * @see #setSkippedWallTimeOption
961      * @stable ICU 49
962      */
963     UCalendarWallTimeOption getSkippedWallTimeOption(void) const;
964 
965     /**
966      * Sets what the first day of the week is; e.g., Sunday in US, Monday in France.
967      *
968      * @param value  The given first day of the week.
969      * @stable ICU 2.6.
970      */
971     void setFirstDayOfWeek(UCalendarDaysOfWeek value);
972 
973 #ifndef U_HIDE_DEPRECATED_API
974     /**
975      * Gets what the first day of the week is; e.g., Sunday in US, Monday in France.
976      *
977      * @return   The first day of the week.
978      * @deprecated ICU 2.6 use the overload with error code
979      */
980     EDaysOfWeek getFirstDayOfWeek(void) const;
981 #endif  /* U_HIDE_DEPRECATED_API */
982 
983     /**
984      * Gets what the first day of the week is; e.g., Sunday in US, Monday in France.
985      *
986      * @param status error code
987      * @return   The first day of the week.
988      * @stable ICU 2.6
989      */
990     UCalendarDaysOfWeek getFirstDayOfWeek(UErrorCode &status) const;
991 
992     /**
993      * Sets what the minimal days required in the first week of the year are; For
994      * example, if the first week is defined as one that contains the first day of the
995      * first month of a year, call the method with value 1. If it must be a full week,
996      * use value 7.
997      *
998      * @param value  The given minimal days required in the first week of the year.
999      * @stable ICU 2.0
1000      */
1001     void setMinimalDaysInFirstWeek(uint8_t value);
1002 
1003     /**
1004      * Gets what the minimal days required in the first week of the year are; e.g., if
1005      * the first week is defined as one that contains the first day of the first month
1006      * of a year, getMinimalDaysInFirstWeek returns 1. If the minimal days required must
1007      * be a full week, getMinimalDaysInFirstWeek returns 7.
1008      *
1009      * @return   The minimal days required in the first week of the year.
1010      * @stable ICU 2.0
1011      */
1012     uint8_t getMinimalDaysInFirstWeek(void) const;
1013 
1014 #ifndef U_FORCE_HIDE_DEPRECATED_API
1015     /**
1016      * Gets the minimum value for the given time field. e.g., for Gregorian
1017      * DAY_OF_MONTH, 1.
1018      *
1019      * @param field  The given time field.
1020      * @return       The minimum value for the given time field.
1021      * @deprecated ICU 2.6. Use getMinimum(UCalendarDateFields field) instead.
1022      */
1023     virtual int32_t getMinimum(EDateFields field) const;
1024 #endif  // U_FORCE_HIDE_DEPRECATED_API
1025 
1026     /**
1027      * Gets the minimum value for the given time field. e.g., for Gregorian
1028      * DAY_OF_MONTH, 1.
1029      *
1030      * @param field  The given time field.
1031      * @return       The minimum value for the given time field.
1032      * @stable ICU 2.6.
1033      */
1034     virtual int32_t getMinimum(UCalendarDateFields field) const;
1035 
1036 #ifndef U_FORCE_HIDE_DEPRECATED_API
1037     /**
1038      * Gets the maximum value for the given time field. e.g. for Gregorian DAY_OF_MONTH,
1039      * 31.
1040      *
1041      * @param field  The given time field.
1042      * @return       The maximum value for the given time field.
1043      * @deprecated ICU 2.6. Use getMaximum(UCalendarDateFields field) instead.
1044      */
1045     virtual int32_t getMaximum(EDateFields field) const;
1046 #endif  // U_FORCE_HIDE_DEPRECATED_API
1047 
1048     /**
1049      * Gets the maximum value for the given time field. e.g. for Gregorian DAY_OF_MONTH,
1050      * 31.
1051      *
1052      * @param field  The given time field.
1053      * @return       The maximum value for the given time field.
1054      * @stable ICU 2.6.
1055      */
1056     virtual int32_t getMaximum(UCalendarDateFields field) const;
1057 
1058 #ifndef U_FORCE_HIDE_DEPRECATED_API
1059     /**
1060      * Gets the highest minimum value for the given field if varies. Otherwise same as
1061      * getMinimum(). For Gregorian, no difference.
1062      *
1063      * @param field  The given time field.
1064      * @return       The highest minimum value for the given time field.
1065      * @deprecated ICU 2.6. Use getGreatestMinimum(UCalendarDateFields field) instead.
1066      */
1067     virtual int32_t getGreatestMinimum(EDateFields field) const;
1068 #endif  // U_FORCE_HIDE_DEPRECATED_API
1069 
1070     /**
1071      * Gets the highest minimum value for the given field if varies. Otherwise same as
1072      * getMinimum(). For Gregorian, no difference.
1073      *
1074      * @param field  The given time field.
1075      * @return       The highest minimum value for the given time field.
1076      * @stable ICU 2.6.
1077      */
1078     virtual int32_t getGreatestMinimum(UCalendarDateFields field) const;
1079 
1080 #ifndef U_FORCE_HIDE_DEPRECATED_API
1081     /**
1082      * Gets the lowest maximum value for the given field if varies. Otherwise same as
1083      * getMaximum(). e.g., for Gregorian DAY_OF_MONTH, 28.
1084      *
1085      * @param field  The given time field.
1086      * @return       The lowest maximum value for the given time field.
1087      * @deprecated ICU 2.6. Use getLeastMaximum(UCalendarDateFields field) instead.
1088      */
1089     virtual int32_t getLeastMaximum(EDateFields field) const;
1090 #endif  // U_FORCE_HIDE_DEPRECATED_API
1091 
1092     /**
1093      * Gets the lowest maximum value for the given field if varies. Otherwise same as
1094      * getMaximum(). e.g., for Gregorian DAY_OF_MONTH, 28.
1095      *
1096      * @param field  The given time field.
1097      * @return       The lowest maximum value for the given time field.
1098      * @stable ICU 2.6.
1099      */
1100     virtual int32_t getLeastMaximum(UCalendarDateFields field) const;
1101 
1102 #ifndef U_HIDE_DEPRECATED_API
1103     /**
1104      * Return the minimum value that this field could have, given the current date.
1105      * For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
1106      *
1107      * The version of this function on Calendar uses an iterative algorithm to determine the
1108      * actual minimum value for the field.  There is almost always a more efficient way to
1109      * accomplish this (in most cases, you can simply return getMinimum()).  GregorianCalendar
1110      * overrides this function with a more efficient implementation.
1111      *
1112      * @param field    the field to determine the minimum of
1113      * @param status   Fill-in parameter which receives the status of this operation.
1114      * @return         the minimum of the given field for the current date of this Calendar
1115      * @deprecated ICU 2.6. Use getActualMinimum(UCalendarDateFields field, UErrorCode& status) instead.
1116      */
1117     int32_t getActualMinimum(EDateFields field, UErrorCode& status) const;
1118 #endif  /* U_HIDE_DEPRECATED_API */
1119 
1120     /**
1121      * Return the minimum value that this field could have, given the current date.
1122      * For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
1123      *
1124      * The version of this function on Calendar uses an iterative algorithm to determine the
1125      * actual minimum value for the field.  There is almost always a more efficient way to
1126      * accomplish this (in most cases, you can simply return getMinimum()).  GregorianCalendar
1127      * overrides this function with a more efficient implementation.
1128      *
1129      * @param field    the field to determine the minimum of
1130      * @param status   Fill-in parameter which receives the status of this operation.
1131      * @return         the minimum of the given field for the current date of this Calendar
1132      * @stable ICU 2.6.
1133      */
1134     virtual int32_t getActualMinimum(UCalendarDateFields field, UErrorCode& status) const;
1135 
1136     /**
1137      * Return the maximum value that this field could have, given the current date.
1138      * For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual
1139      * maximum would be 28; for "Feb 3, 1996" it s 29.  Similarly for a Hebrew calendar,
1140      * for some years the actual maximum for MONTH is 12, and for others 13.
1141      *
1142      * The version of this function on Calendar uses an iterative algorithm to determine the
1143      * actual maximum value for the field.  There is almost always a more efficient way to
1144      * accomplish this (in most cases, you can simply return getMaximum()).  GregorianCalendar
1145      * overrides this function with a more efficient implementation.
1146      *
1147      * @param field    the field to determine the maximum of
1148      * @param status   Fill-in parameter which receives the status of this operation.
1149      * @return         the maximum of the given field for the current date of this Calendar
1150      * @stable ICU 2.6.
1151      */
1152     virtual int32_t getActualMaximum(UCalendarDateFields field, UErrorCode& status) const;
1153 
1154     /**
1155      * Gets the value for a given time field. Recalculate the current time field values
1156      * if the time value has been changed by a call to setTime(). Return zero for unset
1157      * fields if any fields have been explicitly set by a call to set(). To force a
1158      * recomputation of all fields regardless of the previous state, call complete().
1159      * This method is semantically const, but may alter the object in memory.
1160      *
1161      * @param field  The given time field.
1162      * @param status Fill-in parameter which receives the status of the operation.
1163      * @return       The value for the given time field, or zero if the field is unset,
1164      *               and set() has been called for any other field.
1165      * @stable ICU 2.6.
1166      */
1167     int32_t get(UCalendarDateFields field, UErrorCode& status) const;
1168 
1169     /**
1170      * Determines if the given time field has a value set. This can affect in the
1171      * resolving of time in Calendar. Unset fields have a value of zero, by definition.
1172      *
1173      * @param field  The given time field.
1174      * @return   True if the given time field has a value set; false otherwise.
1175      * @stable ICU 2.6.
1176      */
1177     UBool isSet(UCalendarDateFields field) const;
1178 
1179     /**
1180      * Sets the given time field with the given value.
1181      *
1182      * @param field  The given time field.
1183      * @param value  The value to be set for the given time field.
1184      * @stable ICU 2.6.
1185      */
1186     void set(UCalendarDateFields field, int32_t value);
1187 
1188     /**
1189      * Sets the values for the fields YEAR, MONTH, and DATE. Other field values are
1190      * retained; call clear() first if this is not desired.
1191      *
1192      * @param year   The value used to set the YEAR time field.
1193      * @param month  The value used to set the MONTH time field. Month value is 0-based.
1194      *               e.g., 0 for January.
1195      * @param date   The value used to set the DATE time field.
1196      * @stable ICU 2.0
1197      */
1198     void set(int32_t year, int32_t month, int32_t date);
1199 
1200     /**
1201      * Sets the values for the fields YEAR, MONTH, DATE, HOUR_OF_DAY, and MINUTE. Other
1202      * field values are retained; call clear() first if this is not desired.
1203      *
1204      * @param year    The value used to set the YEAR time field.
1205      * @param month   The value used to set the MONTH time field. Month value is
1206      *                0-based. E.g., 0 for January.
1207      * @param date    The value used to set the DATE time field.
1208      * @param hour    The value used to set the HOUR_OF_DAY time field.
1209      * @param minute  The value used to set the MINUTE time field.
1210      * @stable ICU 2.0
1211      */
1212     void set(int32_t year, int32_t month, int32_t date, int32_t hour, int32_t minute);
1213 
1214     /**
1215      * Sets the values for the fields YEAR, MONTH, DATE, HOUR_OF_DAY, MINUTE, and SECOND.
1216      * Other field values are retained; call clear() first if this is not desired.
1217      *
1218      * @param year    The value used to set the YEAR time field.
1219      * @param month   The value used to set the MONTH time field. Month value is
1220      *                0-based. E.g., 0 for January.
1221      * @param date    The value used to set the DATE time field.
1222      * @param hour    The value used to set the HOUR_OF_DAY time field.
1223      * @param minute  The value used to set the MINUTE time field.
1224      * @param second  The value used to set the SECOND time field.
1225      * @stable ICU 2.0
1226      */
1227     void set(int32_t year, int32_t month, int32_t date, int32_t hour, int32_t minute, int32_t second);
1228 
1229     /**
1230      * Clears the values of all the time fields, making them both unset and assigning
1231      * them a value of zero. The field values will be determined during the next
1232      * resolving of time into time fields.
1233      * @stable ICU 2.0
1234      */
1235     void clear(void);
1236 
1237     /**
1238      * Clears the value in the given time field, both making it unset and assigning it a
1239      * value of zero. This field value will be determined during the next resolving of
1240      * time into time fields.
1241      *
1242      * @param field  The time field to be cleared.
1243      * @stable ICU 2.6.
1244      */
1245     void clear(UCalendarDateFields field);
1246 
1247     /**
1248      * Returns a unique class ID POLYMORPHICALLY. Pure virtual method. This method is to
1249      * implement a simple version of RTTI, since not all C++ compilers support genuine
1250      * RTTI. Polymorphic operator==() and clone() methods call this method.
1251      * <P>
1252      * Concrete subclasses of Calendar must implement getDynamicClassID() and also a
1253      * static method and data member:
1254      *
1255      *      static UClassID getStaticClassID() { return (UClassID)&amp;fgClassID; }
1256      *      static char fgClassID;
1257      *
1258      * @return   The class ID for this object. All objects of a given class have the
1259      *           same class ID. Objects of other classes have different class IDs.
1260      * @stable ICU 2.0
1261      */
1262     virtual UClassID getDynamicClassID(void) const override = 0;
1263 
1264     /**
1265      * Returns the calendar type name string for this Calendar object.
1266      * The returned string is the legacy ICU calendar attribute value,
1267      * for example, "gregorian" or "japanese".
1268      *
1269      * See type="old type name" for the calendar attribute of locale IDs
1270      * at http://www.unicode.org/reports/tr35/#Key_Type_Definitions
1271      *
1272      * Sample code for getting the LDML/BCP 47 calendar key value:
1273      * \code
1274      * const char *calType = cal->getType();
1275      * if (0 == strcmp(calType, "unknown")) {
1276      *     // deal with unknown calendar type
1277      * } else {
1278      *     string localeID("root@calendar=");
1279      *     localeID.append(calType);
1280      *     char langTag[100];
1281      *     UErrorCode errorCode = U_ZERO_ERROR;
1282      *     int32_t length = uloc_toLanguageTag(localeID.c_str(), langTag, (int32_t)sizeof(langTag), true, &errorCode);
1283      *     if (U_FAILURE(errorCode)) {
1284      *         // deal with errors & overflow
1285      *     }
1286      *     string lang(langTag, length);
1287      *     size_t caPos = lang.find("-ca-");
1288      *     lang.erase(0, caPos + 4);
1289      *     // lang now contains the LDML calendar type
1290      * }
1291      * \endcode
1292      *
1293      * @return legacy calendar type name string
1294      * @stable ICU 49
1295      */
1296     virtual const char * getType() const = 0;
1297 
1298     /**
1299      * Returns whether the given day of the week is a weekday, a weekend day,
1300      * or a day that transitions from one to the other, for the locale and
1301      * calendar system associated with this Calendar (the locale's region is
1302      * often the most determinant factor). If a transition occurs at midnight,
1303      * then the days before and after the transition will have the
1304      * type UCAL_WEEKDAY or UCAL_WEEKEND. If a transition occurs at a time
1305      * other than midnight, then the day of the transition will have
1306      * the type UCAL_WEEKEND_ONSET or UCAL_WEEKEND_CEASE. In this case, the
1307      * method getWeekendTransition() will return the point of
1308      * transition.
1309      * @param dayOfWeek The day of the week whose type is desired (UCAL_SUNDAY..UCAL_SATURDAY).
1310      * @param status The error code for the operation.
1311      * @return The UCalendarWeekdayType for the day of the week.
1312      * @stable ICU 4.4
1313      */
1314     virtual UCalendarWeekdayType getDayOfWeekType(UCalendarDaysOfWeek dayOfWeek, UErrorCode &status) const;
1315 
1316     /**
1317      * Returns the time during the day at which the weekend begins or ends in
1318      * this calendar system.  If getDayOfWeekType() returns UCAL_WEEKEND_ONSET
1319      * for the specified dayOfWeek, return the time at which the weekend begins.
1320      * If getDayOfWeekType() returns UCAL_WEEKEND_CEASE for the specified dayOfWeek,
1321      * return the time at which the weekend ends. If getDayOfWeekType() returns
1322      * some other UCalendarWeekdayType for the specified dayOfWeek, is it an error condition
1323      * (U_ILLEGAL_ARGUMENT_ERROR).
1324      * @param dayOfWeek The day of the week for which the weekend transition time is
1325      * desired (UCAL_SUNDAY..UCAL_SATURDAY).
1326      * @param status The error code for the operation.
1327      * @return The milliseconds after midnight at which the weekend begins or ends.
1328      * @stable ICU 4.4
1329      */
1330     virtual int32_t getWeekendTransition(UCalendarDaysOfWeek dayOfWeek, UErrorCode &status) const;
1331 
1332     /**
1333      * Returns true if the given UDate is in the weekend in
1334      * this calendar system.
1335      * @param date The UDate in question.
1336      * @param status The error code for the operation.
1337      * @return true if the given UDate is in the weekend in
1338      * this calendar system, false otherwise.
1339      * @stable ICU 4.4
1340      */
1341     virtual UBool isWeekend(UDate date, UErrorCode &status) const;
1342 
1343     /**
1344      * Returns true if this Calendar's current date-time is in the weekend in
1345      * this calendar system.
1346      * @return true if this Calendar's current date-time is in the weekend in
1347      * this calendar system, false otherwise.
1348      * @stable ICU 4.4
1349      */
1350     virtual UBool isWeekend(void) const;
1351 
1352 protected:
1353 
1354      /**
1355       * Constructs a Calendar with the default time zone as returned by
1356       * TimeZone::createInstance(), and the default locale.
1357       *
1358       * @param success  Indicates the status of Calendar object construction. Returns
1359       *                 U_ZERO_ERROR if constructed successfully.
1360      * @stable ICU 2.0
1361       */
1362     Calendar(UErrorCode& success);
1363 
1364     /**
1365      * Copy constructor
1366      *
1367      * @param source    Calendar object to be copied from
1368      * @stable ICU 2.0
1369      */
1370     Calendar(const Calendar& source);
1371 
1372     /**
1373      * Default assignment operator
1374      *
1375      * @param right    Calendar object to be copied
1376      * @stable ICU 2.0
1377      */
1378     Calendar& operator=(const Calendar& right);
1379 
1380     /**
1381      * Constructs a Calendar with the given time zone and locale. Clients are no longer
1382      * responsible for deleting the given time zone object after it's adopted.
1383      *
1384      * @param zone     The given time zone.
1385      * @param aLocale  The given locale.
1386      * @param success  Indicates the status of Calendar object construction. Returns
1387      *                 U_ZERO_ERROR if constructed successfully.
1388      * @stable ICU 2.0
1389      */
1390     Calendar(TimeZone* zone, const Locale& aLocale, UErrorCode& success);
1391 
1392     /**
1393      * Constructs a Calendar with the given time zone and locale.
1394      *
1395      * @param zone     The given time zone.
1396      * @param aLocale  The given locale.
1397      * @param success  Indicates the status of Calendar object construction. Returns
1398      *                 U_ZERO_ERROR if constructed successfully.
1399      * @stable ICU 2.0
1400      */
1401     Calendar(const TimeZone& zone, const Locale& aLocale, UErrorCode& success);
1402 
1403     /**
1404      * Converts Calendar's time field values to GMT as milliseconds.
1405      *
1406      * @param status  Output param set to success/failure code on exit. If any value
1407      *                previously set in the time field is invalid or restricted by
1408      *                leniency, this will be set to an error status.
1409      * @stable ICU 2.0
1410      */
1411     virtual void computeTime(UErrorCode& status);
1412 
1413     /**
1414      * Converts GMT as milliseconds to time field values. This allows you to sync up the
1415      * time field values with a new time that is set for the calendar.  This method
1416      * does NOT recompute the time first; to recompute the time, then the fields, use
1417      * the method complete().
1418      *
1419      * @param status  Output param set to success/failure code on exit. If any value
1420      *                previously set in the time field is invalid or restricted by
1421      *                leniency, this will be set to an error status.
1422      * @stable ICU 2.0
1423      */
1424     virtual void computeFields(UErrorCode& status);
1425 
1426     /**
1427      * Gets this Calendar's current time as a long.
1428      *
1429      * @param status  Output param set to success/failure code on exit. If any value
1430      *                previously set in the time field is invalid or restricted by
1431      *                leniency, this will be set to an error status.
1432      * @return the current time as UTC milliseconds from the epoch.
1433      * @stable ICU 2.0
1434      */
1435     double getTimeInMillis(UErrorCode& status) const;
1436 
1437     /**
1438      * Sets this Calendar's current time from the given long value.
1439      * @param millis  the new time in UTC milliseconds from the epoch.
1440      * @param status  Output param set to success/failure code on exit. If any value
1441      *                previously set in the time field is invalid or restricted by
1442      *                leniency, this will be set to an error status.
1443      * @stable ICU 2.0
1444      */
1445     void setTimeInMillis( double millis, UErrorCode& status );
1446 
1447     /**
1448      * Recomputes the current time from currently set fields, and then fills in any
1449      * unset fields in the time field list.
1450      *
1451      * @param status  Output param set to success/failure code on exit. If any value
1452      *                previously set in the time field is invalid or restricted by
1453      *                leniency, this will be set to an error status.
1454      * @stable ICU 2.0
1455      */
1456     void complete(UErrorCode& status);
1457 
1458 #ifndef U_HIDE_DEPRECATED_API
1459     /**
1460      * Gets the value for a given time field. Subclasses can use this function to get
1461      * field values without forcing recomputation of time.
1462      *
1463      * @param field  The given time field.
1464      * @return       The value for the given time field.
1465      * @deprecated ICU 2.6. Use internalGet(UCalendarDateFields field) instead.
1466      */
internalGet(EDateFields field)1467     inline int32_t internalGet(EDateFields field) const {return fFields[field];}
1468 #endif  /* U_HIDE_DEPRECATED_API */
1469 
1470 #ifndef U_HIDE_INTERNAL_API
1471     /**
1472      * Gets the value for a given time field. Subclasses can use this function to get
1473      * field values without forcing recomputation of time. If the field's stamp is UNSET,
1474      * the defaultValue is used.
1475      *
1476      * @param field  The given time field.
1477      * @param defaultValue a default value used if the field is unset.
1478      * @return       The value for the given time field.
1479      * @internal
1480      */
internalGet(UCalendarDateFields field,int32_t defaultValue)1481     inline int32_t internalGet(UCalendarDateFields field, int32_t defaultValue) const {return fStamp[field]>kUnset ? fFields[field] : defaultValue;}
1482 
1483     /**
1484      * Gets the value for a given time field. Subclasses can use this function to get
1485      * field values without forcing recomputation of time.
1486      *
1487      * @param field  The given time field.
1488      * @return       The value for the given time field.
1489      * @internal
1490      */
internalGet(UCalendarDateFields field)1491     inline int32_t internalGet(UCalendarDateFields field) const {return fFields[field];}
1492 #endif  /* U_HIDE_INTERNAL_API */
1493 
1494 #ifndef U_HIDE_DEPRECATED_API
1495     /**
1496      * Sets the value for a given time field.  This is a fast internal method for
1497      * subclasses.  It does not affect the areFieldsInSync, isTimeSet, or areAllFieldsSet
1498      * flags.
1499      *
1500      * @param field    The given time field.
1501      * @param value    The value for the given time field.
1502      * @deprecated ICU 2.6. Use internalSet(UCalendarDateFields field, int32_t value) instead.
1503      */
1504     void internalSet(EDateFields field, int32_t value);
1505 #endif  /* U_HIDE_DEPRECATED_API */
1506 
1507     /**
1508      * Sets the value for a given time field.  This is a fast internal method for
1509      * subclasses.  It does not affect the areFieldsInSync, isTimeSet, or areAllFieldsSet
1510      * flags.
1511      *
1512      * @param field    The given time field.
1513      * @param value    The value for the given time field.
1514      * @stable ICU 2.6.
1515      */
1516     inline void internalSet(UCalendarDateFields field, int32_t value);
1517 
1518     /**
1519      * Prepare this calendar for computing the actual minimum or maximum.
1520      * This method modifies this calendar's fields; it is called on a
1521      * temporary calendar.
1522      * @internal
1523      */
1524     virtual void prepareGetActual(UCalendarDateFields field, UBool isMinimum, UErrorCode &status);
1525 
1526     /**
1527      * Limit enums. Not in sync with UCalendarLimitType (refers to internal fields).
1528      * @internal
1529      */
1530     enum ELimitType {
1531 #ifndef U_HIDE_INTERNAL_API
1532       UCAL_LIMIT_MINIMUM = 0,
1533       UCAL_LIMIT_GREATEST_MINIMUM,
1534       UCAL_LIMIT_LEAST_MAXIMUM,
1535       UCAL_LIMIT_MAXIMUM,
1536       UCAL_LIMIT_COUNT
1537 #endif  /* U_HIDE_INTERNAL_API */
1538     };
1539 
1540     /**
1541      * Subclass API for defining limits of different types.
1542      * Subclasses must implement this method to return limits for the
1543      * following fields:
1544      *
1545      * <pre>UCAL_ERA
1546      * UCAL_YEAR
1547      * UCAL_MONTH
1548      * UCAL_WEEK_OF_YEAR
1549      * UCAL_WEEK_OF_MONTH
1550      * UCAL_DATE (DAY_OF_MONTH on Java)
1551      * UCAL_DAY_OF_YEAR
1552      * UCAL_DAY_OF_WEEK_IN_MONTH
1553      * UCAL_YEAR_WOY
1554      * UCAL_EXTENDED_YEAR</pre>
1555      *
1556      * @param field one of the above field numbers
1557      * @param limitType one of <code>MINIMUM</code>, <code>GREATEST_MINIMUM</code>,
1558      * <code>LEAST_MAXIMUM</code>, or <code>MAXIMUM</code>
1559      * @internal
1560      */
1561     virtual int32_t handleGetLimit(UCalendarDateFields field, ELimitType limitType) const = 0;
1562 
1563     /**
1564      * Return a limit for a field.
1565      * @param field the field, from <code>0..UCAL_MAX_FIELD</code>
1566      * @param limitType the type specifier for the limit
1567      * @see #ELimitType
1568      * @internal
1569      */
1570     virtual int32_t getLimit(UCalendarDateFields field, ELimitType limitType) const;
1571 
1572 
1573     /**
1574      * Return the Julian day number of day before the first day of the
1575      * given month in the given extended year.  Subclasses should override
1576      * this method to implement their calendar system.
1577      * @param eyear the extended year
1578      * @param month the zero-based month, or 0 if useMonth is false
1579      * @param useMonth if false, compute the day before the first day of
1580      * the given year, otherwise, compute the day before the first day of
1581      * the given month
1582      * @return the Julian day number of the day before the first
1583      * day of the given month and year
1584      * @internal
1585      */
1586     virtual int32_t handleComputeMonthStart(int32_t eyear, int32_t month,
1587                                                    UBool useMonth) const  = 0;
1588 
1589     /**
1590      * Return the number of days in the given month of the given extended
1591      * year of this calendar system.  Subclasses should override this
1592      * method if they can provide a more correct or more efficient
1593      * implementation than the default implementation in Calendar.
1594      * @internal
1595      */
1596     virtual int32_t handleGetMonthLength(int32_t extendedYear, int32_t month) const ;
1597 
1598     /**
1599      * Return the number of days in the given extended year of this
1600      * calendar system.  Subclasses should override this method if they can
1601      * provide a more correct or more efficient implementation than the
1602      * default implementation in Calendar.
1603      * @stable ICU 2.0
1604      */
1605     virtual int32_t handleGetYearLength(int32_t eyear) const;
1606 
1607 
1608     /**
1609      * Return the extended year defined by the current fields.  This will
1610      * use the UCAL_EXTENDED_YEAR field or the UCAL_YEAR and supra-year fields (such
1611      * as UCAL_ERA) specific to the calendar system, depending on which set of
1612      * fields is newer.
1613      * @return the extended year
1614      * @internal
1615      */
1616     virtual int32_t handleGetExtendedYear() = 0;
1617 
1618     /**
1619      * Subclasses may override this.  This method calls
1620      * handleGetMonthLength() to obtain the calendar-specific month
1621      * length.
1622      * @param bestField which field to use to calculate the date
1623      * @return julian day specified by calendar fields.
1624      * @internal
1625      */
1626     virtual int32_t handleComputeJulianDay(UCalendarDateFields bestField);
1627 
1628     /**
1629      * Subclasses must override this to convert from week fields
1630      * (YEAR_WOY and WEEK_OF_YEAR) to an extended year in the case
1631      * where YEAR, EXTENDED_YEAR are not set.
1632      * The Calendar implementation assumes yearWoy is in extended gregorian form
1633      * @return the extended year, UCAL_EXTENDED_YEAR
1634      * @internal
1635      */
1636     virtual int32_t handleGetExtendedYearFromWeekFields(int32_t yearWoy, int32_t woy);
1637 
1638     /**
1639      * Validate a single field of this calendar.  Subclasses should
1640      * override this method to validate any calendar-specific fields.
1641      * Generic fields can be handled by `Calendar::validateField()`.
1642      * @internal
1643      */
1644     virtual void validateField(UCalendarDateFields field, UErrorCode &status);
1645 
1646 #ifndef U_HIDE_INTERNAL_API
1647     /**
1648      * Compute the Julian day from fields.  Will determine whether to use
1649      * the JULIAN_DAY field directly, or other fields.
1650      * @return the julian day
1651      * @internal
1652      */
1653     int32_t computeJulianDay();
1654 
1655     /**
1656      * Compute the milliseconds in the day from the fields.  This is a
1657      * value from 0 to 23:59:59.999 inclusive, unless fields are out of
1658      * range, in which case it can be an arbitrary value.  This value
1659      * reflects local zone wall time.
1660      * @internal
1661      */
1662     double computeMillisInDay();
1663 
1664     /**
1665      * This method can assume EXTENDED_YEAR has been set.
1666      * @param millis milliseconds of the date fields
1667      * @param millisInDay milliseconds of the time fields; may be out
1668      * or range.
1669      * @param ec Output param set to failure code on function return
1670      *          when this function fails.
1671      * @internal
1672      */
1673     int32_t computeZoneOffset(double millis, double millisInDay, UErrorCode &ec);
1674 
1675 
1676     /**
1677      * Determine the best stamp in a range.
1678      * @param start first enum to look at
1679      * @param end last enum to look at
1680      * @param bestSoFar stamp prior to function call
1681      * @return the stamp value of the best stamp
1682      * @internal
1683      */
1684     int32_t newestStamp(UCalendarDateFields start, UCalendarDateFields end, int32_t bestSoFar) const;
1685 
1686     /**
1687      * Marker for end of resolve set (row or group). Value for field resolution tables.
1688      *
1689      * @see #resolveFields
1690      * @internal
1691      */
1692     static constexpr int32_t kResolveSTOP = -1;
1693     /**
1694      * Value to be bitwised "ORed" against resolve table field values for remapping.
1695      * Example: (UCAL_DATE | kResolveRemap) in 1st column will cause 'UCAL_DATE' to be returned,
1696      * but will not examine the value of UCAL_DATE.
1697      * Value for field resolution tables.
1698      *
1699      * @see #resolveFields
1700      * @internal
1701      */
1702     static constexpr int32_t kResolveRemap = 32;
1703 
1704     /**
1705      * Precedence table for Dates
1706      * @see #resolveFields
1707      * @internal
1708      */
1709     static const UFieldResolutionTable kDatePrecedence[];
1710 
1711     /**
1712      * Precedence table for Year
1713      * @see #resolveFields
1714      * @internal
1715      */
1716     static const UFieldResolutionTable kYearPrecedence[];
1717 
1718     /**
1719      * Precedence table for Day of Week
1720      * @see #resolveFields
1721      * @internal
1722      */
1723     static const UFieldResolutionTable kDOWPrecedence[];
1724 
1725     /**
1726      * Given a precedence table, return the newest field combination in
1727      * the table, or UCAL_FIELD_COUNT if none is found.
1728      *
1729      * <p>The precedence table is a 3-dimensional array of integers.  It
1730      * may be thought of as an array of groups.  Each group is an array of
1731      * lines.  Each line is an array of field numbers.  Within a line, if
1732      * all fields are set, then the time stamp of the line is taken to be
1733      * the stamp of the most recently set field.  If any field of a line is
1734      * unset, then the line fails to match.  Within a group, the line with
1735      * the newest time stamp is selected.  The first field of the line is
1736      * returned to indicate which line matched.
1737      *
1738      * <p>In some cases, it may be desirable to map a line to field that
1739      * whose stamp is NOT examined.  For example, if the best field is
1740      * DAY_OF_WEEK then the DAY_OF_WEEK_IN_MONTH algorithm may be used.  In
1741      * order to do this, insert the value <code>kResolveRemap | F</code> at
1742      * the start of the line, where <code>F</code> is the desired return
1743      * field value.  This field will NOT be examined; it only determines
1744      * the return value if the other fields in the line are the newest.
1745      *
1746      * <p>If all lines of a group contain at least one unset field, then no
1747      * line will match, and the group as a whole will fail to match.  In
1748      * that case, the next group will be processed.  If all groups fail to
1749      * match, then UCAL_FIELD_COUNT is returned.
1750      * @internal
1751      */
1752     UCalendarDateFields resolveFields(const UFieldResolutionTable *precedenceTable);
1753 #endif  /* U_HIDE_INTERNAL_API */
1754 
1755 
1756     /**
1757      * @internal
1758      */
1759     virtual const UFieldResolutionTable* getFieldResolutionTable() const;
1760 
1761 #ifndef U_HIDE_INTERNAL_API
1762     /**
1763      * Return the field that is newer, either defaultField, or
1764      * alternateField.  If neither is newer or neither is set, return defaultField.
1765      * @internal
1766      */
1767     UCalendarDateFields newerField(UCalendarDateFields defaultField, UCalendarDateFields alternateField) const;
1768 #endif  /* U_HIDE_INTERNAL_API */
1769 
1770 
1771 private:
1772     /**
1773      * Helper function for calculating limits by trial and error
1774      * @param field The field being investigated
1775      * @param startValue starting (least max) value of field
1776      * @param endValue ending (greatest max) value of field
1777      * @param status return type
1778      * @internal (private)
1779      */
1780     int32_t getActualHelper(UCalendarDateFields field, int32_t startValue, int32_t endValue, UErrorCode &status) const;
1781 
1782 
1783 protected:
1784     /**
1785      * The flag which indicates if the current time is set in the calendar.
1786      * @stable ICU 2.0
1787      */
1788     UBool      fIsTimeSet;
1789 
1790     /**
1791      * True if the fields are in sync with the currently set time of this Calendar.
1792      * If false, then the next attempt to get the value of a field will
1793      * force a recomputation of all fields from the current value of the time
1794      * field.
1795      * <P>
1796      * This should really be named areFieldsInSync, but the old name is retained
1797      * for backward compatibility.
1798      * @stable ICU 2.0
1799      */
1800     UBool      fAreFieldsSet;
1801 
1802     /**
1803      * True if all of the fields have been set.  This is initially false, and set to
1804      * true by computeFields().
1805      * @stable ICU 2.0
1806      */
1807     UBool      fAreAllFieldsSet;
1808 
1809     /**
1810      * True if all fields have been virtually set, but have not yet been
1811      * computed.  This occurs only in setTimeInMillis().  A calendar set
1812      * to this state will compute all fields from the time if it becomes
1813      * necessary, but otherwise will delay such computation.
1814      * @stable ICU 3.0
1815      */
1816     UBool fAreFieldsVirtuallySet;
1817 
1818     /**
1819      * Get the current time without recomputing.
1820      *
1821      * @return     the current time without recomputing.
1822      * @stable ICU 2.0
1823      */
internalGetTime(void)1824     UDate        internalGetTime(void) const     { return fTime; }
1825 
1826     /**
1827      * Set the current time without affecting flags or fields.
1828      *
1829      * @param time    The time to be set
1830      * @return        the current time without recomputing.
1831      * @stable ICU 2.0
1832      */
internalSetTime(UDate time)1833     void        internalSetTime(UDate time)     { fTime = time; }
1834 
1835     /**
1836      * The time fields containing values into which the millis is computed.
1837      * @stable ICU 2.0
1838      */
1839     int32_t     fFields[UCAL_FIELD_COUNT];
1840 
1841 #ifndef U_FORCE_HIDE_DEPRECATED_API
1842     /**
1843      * The flags which tell if a specified time field for the calendar is set.
1844      * @deprecated ICU 2.8 use (fStamp[n]!=kUnset)
1845      */
1846     UBool      fIsSet[UCAL_FIELD_COUNT];
1847 #endif  // U_FORCE_HIDE_DEPRECATED_API
1848 
1849     /** Special values of stamp[]
1850      * @stable ICU 2.0
1851      */
1852     enum {
1853         kUnset                 = 0,
1854         kInternallySet,
1855         kMinimumUserStamp
1856     };
1857 
1858     /**
1859      * Pseudo-time-stamps which specify when each field was set. There
1860      * are two special values, UNSET and INTERNALLY_SET. Values from
1861      * MINIMUM_USER_SET to Integer.MAX_VALUE are legal user set values.
1862      * @stable ICU 2.0
1863      */
1864     int32_t        fStamp[UCAL_FIELD_COUNT];
1865 
1866     /**
1867      * Subclasses may override this method to compute several fields
1868      * specific to each calendar system.  These are:
1869      *
1870      * <ul><li>ERA
1871      * <li>YEAR
1872      * <li>MONTH
1873      * <li>DAY_OF_MONTH
1874      * <li>DAY_OF_YEAR
1875      * <li>EXTENDED_YEAR</ul>
1876      *
1877      * Subclasses can refer to the DAY_OF_WEEK and DOW_LOCAL fields, which
1878      * will be set when this method is called.  Subclasses can also call
1879      * the getGregorianXxx() methods to obtain Gregorian calendar
1880      * equivalents for the given Julian day.
1881      *
1882      * <p>In addition, subclasses should compute any subclass-specific
1883      * fields, that is, fields from BASE_FIELD_COUNT to
1884      * getFieldCount() - 1.
1885      *
1886      * <p>The default implementation in <code>Calendar</code> implements
1887      * a pure proleptic Gregorian calendar.
1888      * @internal
1889      */
1890     virtual void handleComputeFields(int32_t julianDay, UErrorCode &status);
1891 
1892 #ifndef U_HIDE_INTERNAL_API
1893     /**
1894      * Return the extended year on the Gregorian calendar as computed by
1895      * <code>computeGregorianFields()</code>.
1896      * @internal
1897      */
getGregorianYear()1898     int32_t getGregorianYear() const {
1899         return fGregorianYear;
1900     }
1901 
1902     /**
1903      * Return the month (0-based) on the Gregorian calendar as computed by
1904      * <code>computeGregorianFields()</code>.
1905      * @internal
1906      */
getGregorianMonth()1907     int32_t getGregorianMonth() const {
1908         return fGregorianMonth;
1909     }
1910 
1911     /**
1912      * Return the day of year (1-based) on the Gregorian calendar as
1913      * computed by <code>computeGregorianFields()</code>.
1914      * @internal
1915      */
getGregorianDayOfYear()1916     int32_t getGregorianDayOfYear() const {
1917         return fGregorianDayOfYear;
1918     }
1919 
1920     /**
1921      * Return the day of month (1-based) on the Gregorian calendar as
1922      * computed by <code>computeGregorianFields()</code>.
1923      * @internal
1924      */
getGregorianDayOfMonth()1925     int32_t getGregorianDayOfMonth() const {
1926       return fGregorianDayOfMonth;
1927     }
1928 #endif  /* U_HIDE_INTERNAL_API */
1929 
1930     /**
1931      * Called by computeJulianDay.  Returns the default month (0-based) for the year,
1932      * taking year and era into account.  Defaults to 0 for Gregorian, which doesn't care.
1933      * @param eyear The extended year
1934      * @internal
1935      */
1936     virtual int32_t getDefaultMonthInYear(int32_t eyear) ;
1937 
1938 
1939     /**
1940      * Called by computeJulianDay.  Returns the default day (1-based) for the month,
1941      * taking currently-set year and era into account.  Defaults to 1 for Gregorian.
1942      * @param eyear the extended year
1943      * @param month the month in the year
1944      * @internal
1945      */
1946     virtual int32_t getDefaultDayInMonth(int32_t eyear, int32_t month);
1947 
1948     //-------------------------------------------------------------------------
1949     // Protected utility methods for use by subclasses.  These are very handy
1950     // for implementing add, roll, and computeFields.
1951     //-------------------------------------------------------------------------
1952 
1953     /**
1954      * Adjust the specified field so that it is within
1955      * the allowable range for the date to which this calendar is set.
1956      * For example, in a Gregorian calendar pinning the {@link #UCalendarDateFields DAY_OF_MONTH}
1957      * field for a calendar set to April 31 would cause it to be set
1958      * to April 30.
1959      * <p>
1960      * <b>Subclassing:</b>
1961      * <br>
1962      * This utility method is intended for use by subclasses that need to implement
1963      * their own overrides of {@link #roll roll} and {@link #add add}.
1964      * <p>
1965      * <b>Note:</b>
1966      * <code>pinField</code> is implemented in terms of
1967      * {@link #getActualMinimum getActualMinimum}
1968      * and {@link #getActualMaximum getActualMaximum}.  If either of those methods uses
1969      * a slow, iterative algorithm for a particular field, it would be
1970      * unwise to attempt to call <code>pinField</code> for that field.  If you
1971      * really do need to do so, you should override this method to do
1972      * something more efficient for that field.
1973      * <p>
1974      * @param field The calendar field whose value should be pinned.
1975      * @param status Output param set to failure code on function return
1976      *          when this function fails.
1977      *
1978      * @see #getActualMinimum
1979      * @see #getActualMaximum
1980      * @stable ICU 2.0
1981      */
1982     virtual void pinField(UCalendarDateFields field, UErrorCode& status);
1983 
1984     /**
1985      * Return the week number of a day, within a period. This may be the week number in
1986      * a year or the week number in a month. Usually this will be a value >= 1, but if
1987      * some initial days of the period are excluded from week 1, because
1988      * {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} is > 1, then
1989      * the week number will be zero for those
1990      * initial days. This method requires the day number and day of week for some
1991      * known date in the period in order to determine the day of week
1992      * on the desired day.
1993      * <p>
1994      * <b>Subclassing:</b>
1995      * <br>
1996      * This method is intended for use by subclasses in implementing their
1997      * {@link #computeTime computeTime} and/or {@link #computeFields computeFields} methods.
1998      * It is often useful in {@link #getActualMinimum getActualMinimum} and
1999      * {@link #getActualMaximum getActualMaximum} as well.
2000      * <p>
2001      * This variant is handy for computing the week number of some other
2002      * day of a period (often the first or last day of the period) when its day
2003      * of the week is not known but the day number and day of week for some other
2004      * day in the period (e.g. the current date) <em>is</em> known.
2005      * <p>
2006      * @param desiredDay    The {@link #UCalendarDateFields DAY_OF_YEAR} or
2007      *              {@link #UCalendarDateFields DAY_OF_MONTH} whose week number is desired.
2008      *              Should be 1 for the first day of the period.
2009      *
2010      * @param dayOfPeriod   The {@link #UCalendarDateFields DAY_OF_YEAR}
2011      *              or {@link #UCalendarDateFields DAY_OF_MONTH} for a day in the period whose
2012      *              {@link #UCalendarDateFields DAY_OF_WEEK} is specified by the
2013      *              <code>knownDayOfWeek</code> parameter.
2014      *              Should be 1 for first day of period.
2015      *
2016      * @param dayOfWeek  The {@link #UCalendarDateFields DAY_OF_WEEK} for the day
2017      *              corresponding to the <code>knownDayOfPeriod</code> parameter.
2018      *              1-based with 1=Sunday.
2019      *
2020      * @return      The week number (one-based), or zero if the day falls before
2021      *              the first week because
2022      *              {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek}
2023      *              is more than one.
2024      *
2025      * @stable ICU 2.8
2026      */
2027     int32_t weekNumber(int32_t desiredDay, int32_t dayOfPeriod, int32_t dayOfWeek);
2028 
2029 
2030 #ifndef U_HIDE_INTERNAL_API
2031     /**
2032      * Return the week number of a day, within a period. This may be the week number in
2033      * a year, or the week number in a month. Usually this will be a value >= 1, but if
2034      * some initial days of the period are excluded from week 1, because
2035      * {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} is > 1,
2036      * then the week number will be zero for those
2037      * initial days. This method requires the day of week for the given date in order to
2038      * determine the result.
2039      * <p>
2040      * <b>Subclassing:</b>
2041      * <br>
2042      * This method is intended for use by subclasses in implementing their
2043      * {@link #computeTime computeTime} and/or {@link #computeFields computeFields} methods.
2044      * It is often useful in {@link #getActualMinimum getActualMinimum} and
2045      * {@link #getActualMaximum getActualMaximum} as well.
2046      * <p>
2047      * @param dayOfPeriod   The {@link #UCalendarDateFields DAY_OF_YEAR} or
2048      *                      {@link #UCalendarDateFields DAY_OF_MONTH} whose week number is desired.
2049      *                      Should be 1 for the first day of the period.
2050      *
2051      * @param dayOfWeek     The {@link #UCalendarDateFields DAY_OF_WEEK} for the day
2052      *                      corresponding to the <code>dayOfPeriod</code> parameter.
2053      *                      1-based with 1=Sunday.
2054      *
2055      * @return      The week number (one-based), or zero if the day falls before
2056      *              the first week because
2057      *              {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek}
2058      *              is more than one.
2059      * @internal
2060      */
2061     inline int32_t weekNumber(int32_t dayOfPeriod, int32_t dayOfWeek);
2062 
2063     /**
2064      * returns the local DOW, valid range 0..6
2065      * @internal
2066      */
2067     int32_t getLocalDOW();
2068 #endif  /* U_HIDE_INTERNAL_API */
2069 
2070 private:
2071 
2072     /**
2073      * The next available value for fStamp[]
2074      */
2075     int32_t fNextStamp;// = MINIMUM_USER_STAMP;
2076 
2077     /**
2078      * Recalculates the time stamp array (fStamp).
2079      * Resets fNextStamp to lowest next stamp value.
2080      */
2081     void recalculateStamp();
2082 
2083     /**
2084      * The current time set for the calendar.
2085      */
2086     UDate        fTime;
2087 
2088     /**
2089      * @see   #setLenient
2090      */
2091     UBool      fLenient;
2092 
2093     /**
2094      * Time zone affects the time calculation done by Calendar. Calendar subclasses use
2095      * the time zone data to produce the local time. Always set; never NULL.
2096      */
2097     TimeZone*   fZone;
2098 
2099     /**
2100      * Option for repeated wall time
2101      * @see #setRepeatedWallTimeOption
2102      */
2103     UCalendarWallTimeOption fRepeatedWallTime;
2104 
2105     /**
2106      * Option for skipped wall time
2107      * @see #setSkippedWallTimeOption
2108      */
2109     UCalendarWallTimeOption fSkippedWallTime;
2110 
2111     /**
2112      * Both firstDayOfWeek and minimalDaysInFirstWeek are locale-dependent. They are
2113      * used to figure out the week count for a specific date for a given locale. These
2114      * must be set when a Calendar is constructed. For example, in US locale,
2115      * firstDayOfWeek is SUNDAY; minimalDaysInFirstWeek is 1. They are used to figure
2116      * out the week count for a specific date for a given locale. These must be set when
2117      * a Calendar is constructed.
2118      */
2119     UCalendarDaysOfWeek fFirstDayOfWeek;
2120     uint8_t     fMinimalDaysInFirstWeek;
2121     UCalendarDaysOfWeek fWeekendOnset;
2122     int32_t fWeekendOnsetMillis;
2123     UCalendarDaysOfWeek fWeekendCease;
2124     int32_t fWeekendCeaseMillis;
2125 
2126     /**
2127      * Sets firstDayOfWeek and minimalDaysInFirstWeek. Called at Calendar construction
2128      * time.
2129      *
2130      * @param desiredLocale  The given locale.
2131      * @param type           The calendar type identifier, e.g: gregorian, buddhist, etc.
2132      * @param success        Indicates the status of setting the week count data from
2133      *                       the resource for the given locale. Returns U_ZERO_ERROR if
2134      *                       constructed successfully.
2135      */
2136     void        setWeekData(const Locale& desiredLocale, const char *type, UErrorCode& success);
2137 
2138     /**
2139      * Recompute the time and update the status fields isTimeSet
2140      * and areFieldsSet.  Callers should check isTimeSet and only
2141      * call this method if isTimeSet is false.
2142      *
2143      * @param status  Output param set to success/failure code on exit. If any value
2144      *                previously set in the time field is invalid or restricted by
2145      *                leniency, this will be set to an error status.
2146      */
2147     void updateTime(UErrorCode& status);
2148 
2149     /**
2150      * The Gregorian year, as computed by computeGregorianFields() and
2151      * returned by getGregorianYear().
2152      * @see #computeGregorianFields
2153      */
2154     int32_t fGregorianYear;
2155 
2156     /**
2157      * The Gregorian month, as computed by computeGregorianFields() and
2158      * returned by getGregorianMonth().
2159      * @see #computeGregorianFields
2160      */
2161     int32_t fGregorianMonth;
2162 
2163     /**
2164      * The Gregorian day of the year, as computed by
2165      * computeGregorianFields() and returned by getGregorianDayOfYear().
2166      * @see #computeGregorianFields
2167      */
2168     int32_t fGregorianDayOfYear;
2169 
2170     /**
2171      * The Gregorian day of the month, as computed by
2172      * computeGregorianFields() and returned by getGregorianDayOfMonth().
2173      * @see #computeGregorianFields
2174      */
2175     int32_t fGregorianDayOfMonth;
2176 
2177     /* calculations */
2178 
2179     /**
2180      * Compute the Gregorian calendar year, month, and day of month from
2181      * the given Julian day.  These values are not stored in fields, but in
2182      * member variables gregorianXxx.  Also compute the DAY_OF_WEEK and
2183      * DOW_LOCAL fields.
2184      */
2185     void computeGregorianAndDOWFields(int32_t julianDay, UErrorCode &ec);
2186 
2187 protected:
2188 
2189     /**
2190      * Compute the Gregorian calendar year, month, and day of month from the
2191      * Julian day.  These values are not stored in fields, but in member
2192      * variables gregorianXxx.  They are used for time zone computations and by
2193      * subclasses that are Gregorian derivatives.  Subclasses may call this
2194      * method to perform a Gregorian calendar millis->fields computation.
2195      */
2196     void computeGregorianFields(int32_t julianDay, UErrorCode &ec);
2197 
2198 private:
2199 
2200     /**
2201      * Compute the fields WEEK_OF_YEAR, YEAR_WOY, WEEK_OF_MONTH,
2202      * DAY_OF_WEEK_IN_MONTH, and DOW_LOCAL from EXTENDED_YEAR, YEAR,
2203      * DAY_OF_WEEK, and DAY_OF_YEAR.  The latter fields are computed by the
2204      * subclass based on the calendar system.
2205      *
2206      * <p>The YEAR_WOY field is computed simplistically.  It is equal to YEAR
2207      * most of the time, but at the year boundary it may be adjusted to YEAR-1
2208      * or YEAR+1 to reflect the overlap of a week into an adjacent year.  In
2209      * this case, a simple increment or decrement is performed on YEAR, even
2210      * though this may yield an invalid YEAR value.  For instance, if the YEAR
2211      * is part of a calendar system with an N-year cycle field CYCLE, then
2212      * incrementing the YEAR may involve incrementing CYCLE and setting YEAR
2213      * back to 0 or 1.  This is not handled by this code, and in fact cannot be
2214      * simply handled without having subclasses define an entire parallel set of
2215      * fields for fields larger than or equal to a year.  This additional
2216      * complexity is not warranted, since the intention of the YEAR_WOY field is
2217      * to support ISO 8601 notation, so it will typically be used with a
2218      * proleptic Gregorian calendar, which has no field larger than a year.
2219      */
2220     void computeWeekFields(UErrorCode &ec);
2221 
2222 
2223     /**
2224      * Ensure that each field is within its valid range by calling {@link
2225      * #validateField(int, int&)} on each field that has been set.  This method
2226      * should only be called if this calendar is not lenient.
2227      * @see #isLenient
2228      * @see #validateField(int, int&)
2229      */
2230     void validateFields(UErrorCode &status);
2231 
2232     /**
2233      * Validate a single field of this calendar given its minimum and
2234      * maximum allowed value.  If the field is out of range,
2235      * <code>U_ILLEGAL_ARGUMENT_ERROR</code> will be set.  Subclasses may
2236      * use this method in their implementation of {@link
2237      * #validateField(int, int&)}.
2238      */
2239     void validateField(UCalendarDateFields field, int32_t min, int32_t max, UErrorCode& status);
2240 
2241  protected:
2242 #ifndef U_HIDE_INTERNAL_API
2243     /**
2244      * Convert a quasi Julian date to the day of the week. The Julian date used here is
2245      * not a true Julian date, since it is measured from midnight, not noon. Return
2246      * value is one-based.
2247      *
2248      * @param julian  The given Julian date number.
2249      * @return   Day number from 1..7 (SUN..SAT).
2250      * @internal
2251      */
2252     static uint8_t julianDayToDayOfWeek(double julian);
2253 #endif  /* U_HIDE_INTERNAL_API */
2254 
2255  private:
2256     char validLocale[ULOC_FULLNAME_CAPACITY];
2257     char actualLocale[ULOC_FULLNAME_CAPACITY];
2258 
2259  public:
2260 #if !UCONFIG_NO_SERVICE
2261     /**
2262      * INTERNAL FOR 2.6 --  Registration.
2263      */
2264 
2265 #ifndef U_HIDE_INTERNAL_API
2266     /**
2267      * Return a StringEnumeration over the locales available at the time of the call,
2268      * including registered locales.
2269      * @return a StringEnumeration over the locales available at the time of the call
2270      * @internal
2271      */
2272     static StringEnumeration* getAvailableLocales(void);
2273 
2274     /**
2275      * Register a new Calendar factory.  The factory will be adopted.
2276      * INTERNAL in 2.6
2277      *
2278      * Because ICU may choose to cache Calendars internally, this must
2279      * be called at application startup, prior to any calls to
2280      * Calendar::createInstance to avoid undefined behavior.
2281      *
2282      * @param toAdopt the factory instance to be adopted
2283      * @param status the in/out status code, no special meanings are assigned
2284      * @return a registry key that can be used to unregister this factory
2285      * @internal
2286      */
2287     static URegistryKey registerFactory(ICUServiceFactory* toAdopt, UErrorCode& status);
2288 
2289     /**
2290      * Unregister a previously-registered CalendarFactory using the key returned from the
2291      * register call.  Key becomes invalid after a successful call and should not be used again.
2292      * The CalendarFactory corresponding to the key will be deleted.
2293      * INTERNAL in 2.6
2294      *
2295      * Because ICU may choose to cache Calendars internally, this should
2296      * be called during application shutdown, after all calls to
2297      * Calendar::createInstance to avoid undefined behavior.
2298      *
2299      * @param key the registry key returned by a previous call to registerFactory
2300      * @param status the in/out status code, no special meanings are assigned
2301      * @return true if the factory for the key was successfully unregistered
2302      * @internal
2303      */
2304     static UBool unregister(URegistryKey key, UErrorCode& status);
2305 #endif  /* U_HIDE_INTERNAL_API */
2306 
2307     /**
2308      * Multiple Calendar Implementation
2309      * @internal
2310      */
2311     friend class CalendarFactory;
2312 
2313     /**
2314      * Multiple Calendar Implementation
2315      * @internal
2316      */
2317     friend class CalendarService;
2318 
2319     /**
2320      * Multiple Calendar Implementation
2321      * @internal
2322      */
2323     friend class DefaultCalendarFactory;
2324 #endif /* !UCONFIG_NO_SERVICE */
2325 
2326     /**
2327      * @return true if this calendar has a default century (i.e. 03 -> 2003)
2328      * @internal
2329      */
2330     virtual UBool haveDefaultCentury() const = 0;
2331 
2332     /**
2333      * @return the start of the default century, as a UDate
2334      * @internal
2335      */
2336     virtual UDate defaultCenturyStart() const = 0;
2337     /**
2338      * @return the beginning year of the default century, as a year
2339      * @internal
2340      */
2341     virtual int32_t defaultCenturyStartYear() const = 0;
2342 
2343     /** Get the locale for this calendar object. You can choose between valid and actual locale.
2344      *  @param type type of the locale we're looking for (valid or actual)
2345      *  @param status error code for the operation
2346      *  @return the locale
2347      *  @stable ICU 2.8
2348      */
2349     Locale getLocale(ULocDataLocaleType type, UErrorCode &status) const;
2350 
2351     /**
2352      * @return      The related Gregorian year; will be obtained by modifying the value
2353      *              obtained by get from UCAL_EXTENDED_YEAR field
2354      * @internal
2355      */
2356     virtual int32_t getRelatedYear(UErrorCode &status) const;
2357 
2358     /**
2359      * @param year  The related Gregorian year to set; will be modified as necessary then
2360      *              set in UCAL_EXTENDED_YEAR field
2361      * @internal
2362      */
2363     virtual void setRelatedYear(int32_t year);
2364 
2365 #ifndef U_HIDE_INTERNAL_API
2366     /** Get the locale for this calendar object. You can choose between valid and actual locale.
2367      *  @param type type of the locale we're looking for (valid or actual)
2368      *  @param status error code for the operation
2369      *  @return the locale
2370      *  @internal
2371      */
2372     const char* getLocaleID(ULocDataLocaleType type, UErrorCode &status) const;
2373 #endif  /* U_HIDE_INTERNAL_API */
2374 
2375 private:
2376     /**
2377      * Cast TimeZone used by this object to BasicTimeZone, or NULL if the TimeZone
2378      * is not an instance of BasicTimeZone.
2379      */
2380     BasicTimeZone* getBasicTimeZone() const;
2381 
2382     /**
2383      * Find the previous zone transition near the given time.
2384      * @param base The base time, inclusive
2385      * @param transitionTime Receives the result time
2386      * @param status The error status
2387      * @return true if a transition is found.
2388      */
2389     UBool getImmediatePreviousZoneTransition(UDate base, UDate *transitionTime, UErrorCode& status) const;
2390 
2391 public:
2392 #ifndef U_HIDE_INTERNAL_API
2393     /**
2394      * Creates a new Calendar from a Locale for the cache.
2395      * This method does not set the time or timezone in returned calendar.
2396      * @param locale the locale.
2397      * @param status any error returned here.
2398      * @return the new Calendar object with no time or timezone set.
2399      * @internal For ICU use only.
2400      */
2401     static Calendar * U_EXPORT2 makeInstance(
2402             const Locale &locale, UErrorCode &status);
2403 
2404     /**
2405      * Get the calendar type for given locale.
2406      * @param locale the locale
2407      * @param typeBuffer calendar type returned here
2408      * @param typeBufferSize The size of typeBuffer in bytes. If the type
2409      *   can't fit in the buffer, this method sets status to
2410      *   U_BUFFER_OVERFLOW_ERROR
2411      * @param status error, if any, returned here.
2412      * @internal For ICU use only.
2413      */
2414     static void U_EXPORT2 getCalendarTypeFromLocale(
2415             const Locale &locale,
2416             char *typeBuffer,
2417             int32_t typeBufferSize,
2418             UErrorCode &status);
2419 #endif  /* U_HIDE_INTERNAL_API */
2420 };
2421 
2422 // -------------------------------------
2423 
2424 inline Calendar*
createInstance(TimeZone * zone,UErrorCode & errorCode)2425 Calendar::createInstance(TimeZone* zone, UErrorCode& errorCode)
2426 {
2427     // since the Locale isn't specified, use the default locale
2428     return createInstance(zone, Locale::getDefault(), errorCode);
2429 }
2430 
2431 // -------------------------------------
2432 
2433 inline void
roll(UCalendarDateFields field,UBool up,UErrorCode & status)2434 Calendar::roll(UCalendarDateFields field, UBool up, UErrorCode& status)
2435 {
2436     roll(field, (int32_t)(up ? +1 : -1), status);
2437 }
2438 
2439 #ifndef U_HIDE_DEPRECATED_API
2440 inline void
roll(EDateFields field,UBool up,UErrorCode & status)2441 Calendar::roll(EDateFields field, UBool up, UErrorCode& status)
2442 {
2443     roll((UCalendarDateFields) field, up, status);
2444 }
2445 #endif  /* U_HIDE_DEPRECATED_API */
2446 
2447 
2448 // -------------------------------------
2449 
2450 /**
2451  * Fast method for subclasses.  The caller must maintain fUserSetDSTOffset and
2452  * fUserSetZoneOffset, as well as the isSet[] array.
2453  */
2454 
2455 inline void
internalSet(UCalendarDateFields field,int32_t value)2456 Calendar::internalSet(UCalendarDateFields field, int32_t value)
2457 {
2458     fFields[field] = value;
2459     fStamp[field] = kInternallySet;
2460     fIsSet[field]     = true; // Remove later
2461 }
2462 
2463 
2464 #ifndef U_HIDE_INTERNAL_API
weekNumber(int32_t dayOfPeriod,int32_t dayOfWeek)2465 inline int32_t  Calendar::weekNumber(int32_t dayOfPeriod, int32_t dayOfWeek)
2466 {
2467   return weekNumber(dayOfPeriod, dayOfPeriod, dayOfWeek);
2468 }
2469 #endif  /* U_HIDE_INTERNAL_API */
2470 
2471 U_NAMESPACE_END
2472 
2473 #endif /* #if !UCONFIG_NO_FORMATTING */
2474 
2475 #endif /* U_SHOW_CPLUSPLUS_API */
2476 
2477 #endif // _CALENDAR
2478