1 /*************************************************************************
2 * Copyright (c) 1997-2011, International Business Machines Corporation
3 * and others. All Rights Reserved.
4 **************************************************************************
5 *
6 * File TIMEZONE.H
7 *
8 * Modification History:
9 *
10 * Date Name Description
11 * 04/21/97 aliu Overhauled header.
12 * 07/09/97 helena Changed createInstance to createDefault.
13 * 08/06/97 aliu Removed dependency on internal header for Hashtable.
14 * 08/10/98 stephen Changed getDisplayName() API conventions to match
15 * 08/19/98 stephen Changed createTimeZone() to never return 0
16 * 09/02/98 stephen Sync to JDK 1.2 8/31
17 * - Added getOffset(... monthlen ...)
18 * - Added hasSameRules()
19 * 09/15/98 stephen Added getStaticClassID
20 * 12/03/99 aliu Moved data out of static table into icudata.dll.
21 * Hashtable replaced by new static data structures.
22 * 12/14/99 aliu Made GMT public.
23 * 08/15/01 grhoten Made GMT private and added the getGMT() function
24 **************************************************************************
25 */
26
27 #ifndef TIMEZONE_H
28 #define TIMEZONE_H
29
30 #include "unicode/utypes.h"
31
32 /**
33 * \file
34 * \brief C++ API: TimeZone object
35 */
36
37 #if !UCONFIG_NO_FORMATTING
38
39 #include "unicode/uobject.h"
40 #include "unicode/unistr.h"
41 #include "unicode/ures.h"
42 #include "unicode/ucal.h"
43
44 U_NAMESPACE_BEGIN
45
46 class StringEnumeration;
47
48 /**
49 *
50 * <code>TimeZone</code> represents a time zone offset, and also figures out daylight
51 * savings.
52 *
53 * <p>
54 * Typically, you get a <code>TimeZone</code> using <code>createDefault</code>
55 * which creates a <code>TimeZone</code> based on the time zone where the program
56 * is running. For example, for a program running in Japan, <code>createDefault</code>
57 * creates a <code>TimeZone</code> object based on Japanese Standard Time.
58 *
59 * <p>
60 * You can also get a <code>TimeZone</code> using <code>createTimeZone</code> along
61 * with a time zone ID. For instance, the time zone ID for the US Pacific
62 * Time zone is "America/Los_Angeles". So, you can get a Pacific Time <code>TimeZone</code> object
63 * with:
64 * \htmlonly<blockquote>\endhtmlonly
65 * <pre>
66 * TimeZone *tz = TimeZone::createTimeZone("America/Los_Angeles");
67 * </pre>
68 * \htmlonly</blockquote>\endhtmlonly
69 * You can use <code>getAvailableIDs</code> method to iterate through
70 * all the supported time zone IDs. You can then choose a
71 * supported ID to get a <code>TimeZone</code>.
72 * If the time zone you want is not represented by one of the
73 * supported IDs, then you can create a custom time zone ID with
74 * the following syntax:
75 *
76 * \htmlonly<blockquote>\endhtmlonly
77 * <pre>
78 * GMT[+|-]hh[[:]mm]
79 * </pre>
80 * \htmlonly</blockquote>\endhtmlonly
81 *
82 * For example, you might specify GMT+14:00 as a custom
83 * time zone ID. The <code>TimeZone</code> that is returned
84 * when you specify a custom time zone ID does not include
85 * daylight savings time.
86 *
87 * TimeZone is an abstract class representing a time zone. A TimeZone is needed for
88 * Calendar to produce local time for a particular time zone. A TimeZone comprises
89 * three basic pieces of information:
90 * <ul>
91 * <li>A time zone offset; that, is the number of milliseconds to add or subtract
92 * from a time expressed in terms of GMT to convert it to the same time in that
93 * time zone (without taking daylight savings time into account).</li>
94 * <li>Logic necessary to take daylight savings time into account if daylight savings
95 * time is observed in that time zone (e.g., the days and hours on which daylight
96 * savings time begins and ends).</li>
97 * <li>An ID. This is a text string that uniquely identifies the time zone.</li>
98 * </ul>
99 *
100 * (Only the ID is actually implemented in TimeZone; subclasses of TimeZone may handle
101 * daylight savings time and GMT offset in different ways. Currently we only have one
102 * TimeZone subclass: SimpleTimeZone.)
103 * <P>
104 * The TimeZone class contains a static list containing a TimeZone object for every
105 * combination of GMT offset and daylight-savings time rules currently in use in the
106 * world, each with a unique ID. Each ID consists of a region (usually a continent or
107 * ocean) and a city in that region, separated by a slash, (for example, US Pacific
108 * Time is "America/Los_Angeles.") Because older versions of this class used
109 * three- or four-letter abbreviations instead, there is also a table that maps the older
110 * abbreviations to the newer ones (for example, "PST" maps to "America/Los_Angeles").
111 * Anywhere the API requires an ID, you can use either form.
112 * <P>
113 * To create a new TimeZone, you call the factory function TimeZone::createTimeZone()
114 * and pass it a time zone ID. You can use the createEnumeration() function to
115 * obtain a list of all the time zone IDs recognized by createTimeZone().
116 * <P>
117 * You can also use TimeZone::createDefault() to create a TimeZone. This function uses
118 * platform-specific APIs to produce a TimeZone for the time zone corresponding to
119 * the client's computer's physical location. For example, if you're in Japan (assuming
120 * your machine is set up correctly), TimeZone::createDefault() will return a TimeZone
121 * for Japanese Standard Time ("Asia/Tokyo").
122 */
123 class U_I18N_API TimeZone : public UObject {
124 public:
125 /**
126 * @stable ICU 2.0
127 */
128 virtual ~TimeZone();
129
130 /**
131 * The GMT time zone has a raw offset of zero and does not use daylight
132 * savings time. This is a commonly used time zone.
133 * @return the GMT time zone.
134 * @stable ICU 2.0
135 */
136 static const TimeZone* U_EXPORT2 getGMT(void);
137
138 /**
139 * Creates a <code>TimeZone</code> for the given ID.
140 * @param ID the ID for a <code>TimeZone</code>, such as "America/Los_Angeles",
141 * or a custom ID such as "GMT-8:00".
142 * @return the specified <code>TimeZone</code>, or the GMT zone with ID
143 * <code>UCAL_UNKNOWN_ZONE_ID</code> ("Etc/Unknown") if the given ID cannot be understood.
144 * Return result guaranteed to be non-null. If you require that the specific zone asked
145 * for be returned, check the ID of the return result.
146 * @stable ICU 2.0
147 */
148 static TimeZone* U_EXPORT2 createTimeZone(const UnicodeString& ID);
149
150
151 /**
152 * Returns an enumeration over system time zone IDs with the given
153 * filter conditions.
154 * @param zoneType The system time zone type.
155 * @param region The ISO 3166 two-letter country code or UN M.49
156 * three-digit area code. When NULL, no filtering
157 * done by region.
158 * @param rawOffset An offset from GMT in milliseconds, ignoring
159 * the effect of daylight savings time, if any.
160 * When NULL, no filtering done by zone offset.
161 * @param ec Output param to filled in with a success or
162 * an error.
163 * @return an enumeration object, owned by the caller.
164 * @draft ICU 4.8
165 */
166 static StringEnumeration* U_EXPORT2 createTimeZoneIDEnumeration(
167 USystemTimeZoneType zoneType,
168 const char* region,
169 const int32_t* rawOffset,
170 UErrorCode& ec);
171
172 /**
173 * Returns an enumeration over all recognized time zone IDs. (i.e.,
174 * all strings that createTimeZone() accepts)
175 *
176 * @return an enumeration object, owned by the caller.
177 * @stable ICU 2.4
178 */
179 static StringEnumeration* U_EXPORT2 createEnumeration();
180
181 /**
182 * Returns an enumeration over time zone IDs with a given raw
183 * offset from GMT. There may be several times zones with the
184 * same GMT offset that differ in the way they handle daylight
185 * savings time. For example, the state of Arizona doesn't
186 * observe daylight savings time. If you ask for the time zone
187 * IDs corresponding to GMT-7:00, you'll get back an enumeration
188 * over two time zone IDs: "America/Denver," which corresponds to
189 * Mountain Standard Time in the winter and Mountain Daylight Time
190 * in the summer, and "America/Phoenix", which corresponds to
191 * Mountain Standard Time year-round, even in the summer.
192 *
193 * @param rawOffset an offset from GMT in milliseconds, ignoring
194 * the effect of daylight savings time, if any
195 * @return an enumeration object, owned by the caller
196 * @stable ICU 2.4
197 */
198 static StringEnumeration* U_EXPORT2 createEnumeration(int32_t rawOffset);
199
200 /**
201 * Returns an enumeration over time zone IDs associated with the
202 * given country. Some zones are affiliated with no country
203 * (e.g., "UTC"); these may also be retrieved, as a group.
204 *
205 * @param country The ISO 3166 two-letter country code, or NULL to
206 * retrieve zones not affiliated with any country.
207 * @return an enumeration object, owned by the caller
208 * @stable ICU 2.4
209 */
210 static StringEnumeration* U_EXPORT2 createEnumeration(const char* country);
211
212 /**
213 * Returns the number of IDs in the equivalency group that
214 * includes the given ID. An equivalency group contains zones
215 * that have the same GMT offset and rules.
216 *
217 * <p>The returned count includes the given ID; it is always >= 1.
218 * The given ID must be a system time zone. If it is not, returns
219 * zero.
220 * @param id a system time zone ID
221 * @return the number of zones in the equivalency group containing
222 * 'id', or zero if 'id' is not a valid system ID
223 * @see #getEquivalentID
224 * @stable ICU 2.0
225 */
226 static int32_t U_EXPORT2 countEquivalentIDs(const UnicodeString& id);
227
228 /**
229 * Returns an ID in the equivalency group that
230 * includes the given ID. An equivalency group contains zones
231 * that have the same GMT offset and rules.
232 *
233 * <p>The given index must be in the range 0..n-1, where n is the
234 * value returned by <code>countEquivalentIDs(id)</code>. For
235 * some value of 'index', the returned value will be equal to the
236 * given id. If the given id is not a valid system time zone, or
237 * if 'index' is out of range, then returns an empty string.
238 * @param id a system time zone ID
239 * @param index a value from 0 to n-1, where n is the value
240 * returned by <code>countEquivalentIDs(id)</code>
241 * @return the ID of the index-th zone in the equivalency group
242 * containing 'id', or an empty string if 'id' is not a valid
243 * system ID or 'index' is out of range
244 * @see #countEquivalentIDs
245 * @stable ICU 2.0
246 */
247 static const UnicodeString U_EXPORT2 getEquivalentID(const UnicodeString& id,
248 int32_t index);
249
250 /**
251 * Creates a new copy of the default TimeZone for this host. Unless the default time
252 * zone has already been set using adoptDefault() or setDefault(), the default is
253 * determined by querying the system using methods in TPlatformUtilities. If the
254 * system routines fail, or if they specify a TimeZone or TimeZone offset which is not
255 * recognized, the TimeZone indicated by the ID kLastResortID is instantiated
256 * and made the default.
257 *
258 * @return A default TimeZone. Clients are responsible for deleting the time zone
259 * object returned.
260 * @stable ICU 2.0
261 */
262 static TimeZone* U_EXPORT2 createDefault(void);
263
264 /**
265 * Sets the default time zone (i.e., what's returned by createDefault()) to be the
266 * specified time zone. If NULL is specified for the time zone, the default time
267 * zone is set to the default host time zone. This call adopts the TimeZone object
268 * passed in; the clent is no longer responsible for deleting it.
269 *
270 * @param zone A pointer to the new TimeZone object to use as the default.
271 * @stable ICU 2.0
272 */
273 static void U_EXPORT2 adoptDefault(TimeZone* zone);
274
275 /**
276 * Same as adoptDefault(), except that the TimeZone object passed in is NOT adopted;
277 * the caller remains responsible for deleting it.
278 *
279 * @param zone The given timezone.
280 * @system
281 */
282 static void U_EXPORT2 setDefault(const TimeZone& zone);
283
284 /**
285 * Returns the timezone data version currently used by ICU.
286 * @param status Output param to filled in with a success or an error.
287 * @return the version string, such as "2007f"
288 * @stable ICU 3.8
289 */
290 static const char* U_EXPORT2 getTZDataVersion(UErrorCode& status);
291
292 /**
293 * Returns the canonical system timezone ID or the normalized
294 * custom time zone ID for the given time zone ID.
295 * @param id The input time zone ID to be canonicalized.
296 * @param canonicalID Receives the canonical system time zone ID
297 * or the custom time zone ID in normalized format.
298 * @param status Recevies the status. When the given time zone ID
299 * is neither a known system time zone ID nor a
300 * valid custom time zone ID, U_ILLEGAL_ARGUMENT_ERROR
301 * is set.
302 * @return A reference to the result.
303 * @stable ICU 4.0
304 */
305 static UnicodeString& U_EXPORT2 getCanonicalID(const UnicodeString& id,
306 UnicodeString& canonicalID, UErrorCode& status);
307
308 /**
309 * Returns the canonical system time zone ID or the normalized
310 * custom time zone ID for the given time zone ID.
311 * @param id The input time zone ID to be canonicalized.
312 * @param canonicalID Receives the canonical system time zone ID
313 * or the custom time zone ID in normalized format.
314 * @param isSystemID Receives if the given ID is a known system
315 * time zone ID.
316 * @param status Recevies the status. When the given time zone ID
317 * is neither a known system time zone ID nor a
318 * valid custom time zone ID, U_ILLEGAL_ARGUMENT_ERROR
319 * is set.
320 * @return A reference to the result.
321 * @stable ICU 4.0
322 */
323 static UnicodeString& U_EXPORT2 getCanonicalID(const UnicodeString& id,
324 UnicodeString& canonicalID, UBool& isSystemID, UErrorCode& status);
325
326 /**
327 * Returns true if the two TimeZones are equal. (The TimeZone version only compares
328 * IDs, but subclasses are expected to also compare the fields they add.)
329 *
330 * @param that The TimeZone object to be compared with.
331 * @return True if the given TimeZone is equal to this TimeZone; false
332 * otherwise.
333 * @stable ICU 2.0
334 */
335 virtual UBool operator==(const TimeZone& that) const;
336
337 /**
338 * Returns true if the two TimeZones are NOT equal; that is, if operator==() returns
339 * false.
340 *
341 * @param that The TimeZone object to be compared with.
342 * @return True if the given TimeZone is not equal to this TimeZone; false
343 * otherwise.
344 * @stable ICU 2.0
345 */
346 UBool operator!=(const TimeZone& that) const {return !operator==(that);}
347
348 /**
349 * Returns the TimeZone's adjusted GMT offset (i.e., the number of milliseconds to add
350 * to GMT to get local time in this time zone, taking daylight savings time into
351 * account) as of a particular reference date. The reference date is used to determine
352 * whether daylight savings time is in effect and needs to be figured into the offset
353 * that is returned (in other words, what is the adjusted GMT offset in this time zone
354 * at this particular date and time?). For the time zones produced by createTimeZone(),
355 * the reference data is specified according to the Gregorian calendar, and the date
356 * and time fields are local standard time.
357 *
358 * <p>Note: Don't call this method. Instead, call the getOffset(UDate...) overload,
359 * which returns both the raw and the DST offset for a given time. This method
360 * is retained only for backward compatibility.
361 *
362 * @param era The reference date's era
363 * @param year The reference date's year
364 * @param month The reference date's month (0-based; 0 is January)
365 * @param day The reference date's day-in-month (1-based)
366 * @param dayOfWeek The reference date's day-of-week (1-based; 1 is Sunday)
367 * @param millis The reference date's milliseconds in day, local standard time
368 * @param status Output param to filled in with a success or an error.
369 * @return The offset in milliseconds to add to GMT to get local time.
370 * @stable ICU 2.0
371 */
372 virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day,
373 uint8_t dayOfWeek, int32_t millis, UErrorCode& status) const = 0;
374
375 /**
376 * Gets the time zone offset, for current date, modified in case of
377 * daylight savings. This is the offset to add *to* UTC to get local time.
378 *
379 * <p>Note: Don't call this method. Instead, call the getOffset(UDate...) overload,
380 * which returns both the raw and the DST offset for a given time. This method
381 * is retained only for backward compatibility.
382 *
383 * @param era the era of the given date.
384 * @param year the year in the given date.
385 * @param month the month in the given date.
386 * Month is 0-based. e.g., 0 for January.
387 * @param day the day-in-month of the given date.
388 * @param dayOfWeek the day-of-week of the given date.
389 * @param milliseconds the millis in day in <em>standard</em> local time.
390 * @param monthLength the length of the given month in days.
391 * @param status Output param to filled in with a success or an error.
392 * @return the offset to add *to* GMT to get local time.
393 * @stable ICU 2.0
394 */
395 virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day,
396 uint8_t dayOfWeek, int32_t milliseconds,
397 int32_t monthLength, UErrorCode& status) const = 0;
398
399 /**
400 * Returns the time zone raw and GMT offset for the given moment
401 * in time. Upon return, local-millis = GMT-millis + rawOffset +
402 * dstOffset. All computations are performed in the proleptic
403 * Gregorian calendar. The default implementation in the TimeZone
404 * class delegates to the 8-argument getOffset().
405 *
406 * @param date moment in time for which to return offsets, in
407 * units of milliseconds from January 1, 1970 0:00 GMT, either GMT
408 * time or local wall time, depending on `local'.
409 * @param local if true, `date' is local wall time; otherwise it
410 * is in GMT time.
411 * @param rawOffset output parameter to receive the raw offset, that
412 * is, the offset not including DST adjustments
413 * @param dstOffset output parameter to receive the DST offset,
414 * that is, the offset to be added to `rawOffset' to obtain the
415 * total offset between local and GMT time. If DST is not in
416 * effect, this value is zero; otherwise it is a positive value,
417 * typically one hour.
418 * @param ec input-output error code
419 *
420 * @stable ICU 2.8
421 */
422 virtual void getOffset(UDate date, UBool local, int32_t& rawOffset,
423 int32_t& dstOffset, UErrorCode& ec) const;
424
425 /**
426 * Sets the TimeZone's raw GMT offset (i.e., the number of milliseconds to add
427 * to GMT to get local time, before taking daylight savings time into account).
428 *
429 * @param offsetMillis The new raw GMT offset for this time zone.
430 * @stable ICU 2.0
431 */
432 virtual void setRawOffset(int32_t offsetMillis) = 0;
433
434 /**
435 * Returns the TimeZone's raw GMT offset (i.e., the number of milliseconds to add
436 * to GMT to get local time, before taking daylight savings time into account).
437 *
438 * @return The TimeZone's raw GMT offset.
439 * @stable ICU 2.0
440 */
441 virtual int32_t getRawOffset(void) const = 0;
442
443 /**
444 * Fills in "ID" with the TimeZone's ID.
445 *
446 * @param ID Receives this TimeZone's ID.
447 * @return A reference to 'ID'
448 * @stable ICU 2.0
449 */
450 UnicodeString& getID(UnicodeString& ID) const;
451
452 /**
453 * Sets the TimeZone's ID to the specified value. This doesn't affect any other
454 * fields (for example, if you say<
455 * blockquote><pre>
456 * . TimeZone* foo = TimeZone::createTimeZone("America/New_York");
457 * . foo.setID("America/Los_Angeles");
458 * </pre>\htmlonly</blockquote>\endhtmlonly
459 * the time zone's GMT offset and daylight-savings rules don't change to those for
460 * Los Angeles. They're still those for New York. Only the ID has changed.)
461 *
462 * @param ID The new time zone ID.
463 * @stable ICU 2.0
464 */
465 void setID(const UnicodeString& ID);
466
467 /**
468 * Enum for use with getDisplayName
469 * @stable ICU 2.4
470 */
471 enum EDisplayType {
472 /**
473 * Selector for short display name
474 * @stable ICU 2.4
475 */
476 SHORT = 1,
477 /**
478 * Selector for long display name
479 * @stable ICU 2.4
480 */
481 LONG,
482 /**
483 * Selector for short generic display name
484 * @stable ICU 4.4
485 */
486 SHORT_GENERIC,
487 /**
488 * Selector for long generic display name
489 * @stable ICU 4.4
490 */
491 LONG_GENERIC,
492 /**
493 * Selector for short display name derived
494 * from time zone offset
495 * @stable ICU 4.4
496 */
497 SHORT_GMT,
498 /**
499 * Selector for long display name derived
500 * from time zone offset
501 * @stable ICU 4.4
502 */
503 LONG_GMT,
504 /**
505 * Selector for short display name derived
506 * from the time zone's fallback name
507 * @stable ICU 4.4
508 */
509 SHORT_COMMONLY_USED,
510 /**
511 * Selector for long display name derived
512 * from the time zone's fallback name
513 * @stable ICU 4.4
514 */
515 GENERIC_LOCATION
516 };
517
518 /**
519 * Returns a name of this time zone suitable for presentation to the user
520 * in the default locale.
521 * This method returns the long name, not including daylight savings.
522 * If the display name is not available for the locale,
523 * then this method returns a string in the format
524 * <code>GMT[+-]hh:mm</code>.
525 * @param result the human-readable name of this time zone in the default locale.
526 * @return A reference to 'result'.
527 * @stable ICU 2.0
528 */
529 UnicodeString& getDisplayName(UnicodeString& result) const;
530
531 /**
532 * Returns a name of this time zone suitable for presentation to the user
533 * in the specified locale.
534 * This method returns the long name, not including daylight savings.
535 * If the display name is not available for the locale,
536 * then this method returns a string in the format
537 * <code>GMT[+-]hh:mm</code>.
538 * @param locale the locale in which to supply the display name.
539 * @param result the human-readable name of this time zone in the given locale
540 * or in the default locale if the given locale is not recognized.
541 * @return A reference to 'result'.
542 * @stable ICU 2.0
543 */
544 UnicodeString& getDisplayName(const Locale& locale, UnicodeString& result) const;
545
546 /**
547 * Returns a name of this time zone suitable for presentation to the user
548 * in the default locale.
549 * If the display name is not available for the locale,
550 * then this method returns a string in the format
551 * <code>GMT[+-]hh:mm</code>.
552 * @param daylight if true, return the daylight savings name.
553 * @param style
554 * @param result the human-readable name of this time zone in the default locale.
555 * @return A reference to 'result'.
556 * @stable ICU 2.0
557 */
558 UnicodeString& getDisplayName(UBool daylight, EDisplayType style, UnicodeString& result) const;
559
560 /**
561 * Returns a name of this time zone suitable for presentation to the user
562 * in the specified locale.
563 * If the display name is not available for the locale,
564 * then this method returns a string in the format
565 * <code>GMT[+-]hh:mm</code>.
566 * @param daylight if true, return the daylight savings name.
567 * @param style
568 * @param locale the locale in which to supply the display name.
569 * @param result the human-readable name of this time zone in the given locale
570 * or in the default locale if the given locale is not recognized.
571 * @return A refence to 'result'.
572 * @stable ICU 2.0
573 */
574 UnicodeString& getDisplayName(UBool daylight, EDisplayType style, const Locale& locale, UnicodeString& result) const;
575
576 /**
577 * Queries if this time zone uses daylight savings time.
578 * @return true if this time zone uses daylight savings time,
579 * false, otherwise.
580 * <p><strong>Note:</strong>The default implementation of
581 * ICU TimeZone uses the tz database, which supports historic
582 * rule changes, for system time zones. With the implementation,
583 * there are time zones that used daylight savings time in the
584 * past, but no longer used currently. For example, Asia/Tokyo has
585 * never used daylight savings time since 1951. Most clients would
586 * expect that this method to return <code>FALSE</code> for such case.
587 * The default implementation of this method returns <code>TRUE</code>
588 * when the time zone uses daylight savings time in the current
589 * (Gregorian) calendar year.
590 * @stable ICU 2.0
591 */
592 virtual UBool useDaylightTime(void) const = 0;
593
594 /**
595 * Queries if the given date is in daylight savings time in
596 * this time zone.
597 * This method is wasteful since it creates a new GregorianCalendar and
598 * deletes it each time it is called. This is a deprecated method
599 * and provided only for Java compatibility.
600 *
601 * @param date the given UDate.
602 * @param status Output param filled in with success/error code.
603 * @return true if the given date is in daylight savings time,
604 * false, otherwise.
605 * @deprecated ICU 2.4. Use Calendar::inDaylightTime() instead.
606 */
607 virtual UBool inDaylightTime(UDate date, UErrorCode& status) const = 0;
608
609 /**
610 * Returns true if this zone has the same rule and offset as another zone.
611 * That is, if this zone differs only in ID, if at all.
612 * @param other the <code>TimeZone</code> object to be compared with
613 * @return true if the given zone is the same as this one,
614 * with the possible exception of the ID
615 * @stable ICU 2.0
616 */
617 virtual UBool hasSameRules(const TimeZone& other) const;
618
619 /**
620 * Clones TimeZone objects polymorphically. Clients are responsible for deleting
621 * the TimeZone object cloned.
622 *
623 * @return A new copy of this TimeZone object.
624 * @stable ICU 2.0
625 */
626 virtual TimeZone* clone(void) const = 0;
627
628 /**
629 * Return the class ID for this class. This is useful only for
630 * comparing to a return value from getDynamicClassID().
631 * @return The class ID for all objects of this class.
632 * @stable ICU 2.0
633 */
634 static UClassID U_EXPORT2 getStaticClassID(void);
635
636 /**
637 * Returns a unique class ID POLYMORPHICALLY. This method is to
638 * implement a simple version of RTTI, since not all C++ compilers support genuine
639 * RTTI. Polymorphic operator==() and clone() methods call this method.
640 * <P>
641 * Concrete subclasses of TimeZone must use the UOBJECT_DEFINE_RTTI_IMPLEMENTATION
642 * macro from uobject.h in their implementation to provide correct RTTI information.
643 * @return The class ID for this object. All objects of a given class have the
644 * same class ID. Objects of other classes have different class IDs.
645 * @stable ICU 2.0
646 */
647 virtual UClassID getDynamicClassID(void) const = 0;
648
649 /**
650 * Returns the amount of time to be added to local standard time
651 * to get local wall clock time.
652 * <p>
653 * The default implementation always returns 3600000 milliseconds
654 * (i.e., one hour) if this time zone observes Daylight Saving
655 * Time. Otherwise, 0 (zero) is returned.
656 * <p>
657 * If an underlying TimeZone implementation subclass supports
658 * historical Daylight Saving Time changes, this method returns
659 * the known latest daylight saving value.
660 *
661 * @return the amount of saving time in milliseconds
662 * @stable ICU 3.6
663 */
664 virtual int32_t getDSTSavings() const;
665
666 /**
667 * Gets the region code associated with the given
668 * system time zone ID. The region code is either ISO 3166
669 * 2-letter country code or UN M.49 3-digit area code.
670 * When the time zone is not associated with a specific location,
671 * for example - "Etc/UTC", "EST5EDT", then this method returns
672 * "001" (UN M.49 area code for World).
673 *
674 * @param id The system time zone ID.
675 * @param region Output buffer for receiving the region code.
676 * @param capacity The size of the output buffer.
677 * @param status Receives the status. When the given time zone ID
678 * is not a known system time zone ID,
679 * U_ILLEGAL_ARGUMENT_ERROR is set.
680 * @return The length of the output region code.
681 * @draft ICU 4.8
682 */
683 static int32_t U_EXPORT2 getRegion(const UnicodeString& id,
684 char *region, int32_t capacity, UErrorCode& status);
685
686 protected:
687
688 /**
689 * Default constructor. ID is initialized to the empty string.
690 * @stable ICU 2.0
691 */
692 TimeZone();
693
694 /**
695 * Construct a TimeZone with a given ID.
696 * @param id a system time zone ID
697 * @stable ICU 2.0
698 */
699 TimeZone(const UnicodeString &id);
700
701 /**
702 * Copy constructor.
703 * @param source the object to be copied.
704 * @stable ICU 2.0
705 */
706 TimeZone(const TimeZone& source);
707
708 /**
709 * Default assignment operator.
710 * @param right the object to be copied.
711 * @stable ICU 2.0
712 */
713 TimeZone& operator=(const TimeZone& right);
714
715 /**
716 * Utility function. For internally loading rule data.
717 * @param top Top resource bundle for tz data
718 * @param ruleid ID of rule to load
719 * @param oldbundle Old bundle to reuse or NULL
720 * @param status Status parameter
721 * @return either a new bundle or *oldbundle
722 * @internal
723 */
724 static UResourceBundle* loadRule(const UResourceBundle* top, const UnicodeString& ruleid, UResourceBundle* oldbundle, UErrorCode&status);
725
726
727 private:
728 friend class ZoneMeta;
729
730
731 static TimeZone* createCustomTimeZone(const UnicodeString&); // Creates a time zone based on the string.
732
733 /**
734 * Finds the given ID in the Olson tzdata. If the given ID is found in the tzdata,
735 * returns the pointer to the ID resource. This method is exposed through ZoneMeta class
736 * for ICU internal implementation and useful for building hashtable using a time zone
737 * ID as a key.
738 * @param id zone id string
739 * @return the pointer of the ID resource, or NULL.
740 */
741 static const UChar* findID(const UnicodeString& id);
742
743 /**
744 * Resolve a link in Olson tzdata. When the given id is known and it's not a link,
745 * the id itself is returned. When the given id is known and it is a link, then
746 * dereferenced zone id is returned. When the given id is unknown, then it returns
747 * NULL.
748 * @param id zone id string
749 * @return the dereferenced zone or NULL
750 */
751 static const UChar* dereferOlsonLink(const UnicodeString& id);
752
753 /**
754 * Returns the region code associated with the given zone,
755 * or NULL if the zone is not known.
756 * @param id zone id string
757 * @return the region associated with the given zone
758 */
759 static const UChar* getRegion(const UnicodeString& id);
760
761 /**
762 * Returns the region code associated with the given zone,
763 * or NULL if the zone is not known.
764 * @param id zone id string
765 * @param status Status parameter
766 * @return the region associated with the given zone
767 */
768 static const UChar* getRegion(const UnicodeString& id, UErrorCode& status);
769
770 /**
771 * Parses the given custom time zone identifier
772 * @param id id A string of the form GMT[+-]hh:mm, GMT[+-]hhmm, or
773 * GMT[+-]hh.
774 * @param sign Receves parsed sign, 1 for positive, -1 for negative.
775 * @param hour Receives parsed hour field
776 * @param minute Receives parsed minute field
777 * @param second Receives parsed second field
778 * @return Returns TRUE when the given custom id is valid.
779 */
780 static UBool parseCustomID(const UnicodeString& id, int32_t& sign, int32_t& hour,
781 int32_t& minute, int32_t& second);
782
783 /**
784 * Parse a custom time zone identifier and return the normalized
785 * custom time zone identifier for the given custom id string.
786 * @param id a string of the form GMT[+-]hh:mm, GMT[+-]hhmm, or
787 * GMT[+-]hh.
788 * @param normalized Receives the normalized custom ID
789 * @param status Receives the status. When the input ID string is invalid,
790 * U_ILLEGAL_ARGUMENT_ERROR is set.
791 * @return The normalized custom id string.
792 */
793 static UnicodeString& getCustomID(const UnicodeString& id, UnicodeString& normalized,
794 UErrorCode& status);
795
796 /**
797 * Returns the normalized custome time zone ID for the given offset fields.
798 * @param hour offset hours
799 * @param min offset minutes
800 * @param sec offset seconds
801 * @param negative sign of the offset, TRUE for negative offset.
802 * @param id Receves the format result (normalized custom ID)
803 * @return The reference to id
804 */
805 static UnicodeString& formatCustomID(int32_t hour, int32_t min, int32_t sec,
806 UBool negative, UnicodeString& id);
807
808 /**
809 * Responsible for setting up DEFAULT_ZONE. Uses routines in TPlatformUtilities
810 * (i.e., platform-specific calls) to get the current system time zone. Failing
811 * that, uses the platform-specific default time zone. Failing that, uses GMT.
812 */
813 static void initDefault(void);
814
815 // See source file for documentation
816 /**
817 * Lookup the given name in our system zone table. If found,
818 * instantiate a new zone of that name and return it. If not
819 * found, return 0.
820 * @param name tthe given name of a system time zone.
821 * @return the TimeZone indicated by the 'name'.
822 */
823 static TimeZone* createSystemTimeZone(const UnicodeString& name);
824 static TimeZone* createSystemTimeZone(const UnicodeString& name, UErrorCode& ec);
825
826 UnicodeString fID; // this time zone's ID
827
828 friend class TZEnumeration;
829 };
830
831
832 // -------------------------------------
833
834 inline UnicodeString&
getID(UnicodeString & ID)835 TimeZone::getID(UnicodeString& ID) const
836 {
837 ID = fID;
838 return ID;
839 }
840
841 // -------------------------------------
842
843 inline void
setID(const UnicodeString & ID)844 TimeZone::setID(const UnicodeString& ID)
845 {
846 fID = ID;
847 }
848 U_NAMESPACE_END
849
850 #endif /* #if !UCONFIG_NO_FORMATTING */
851
852 #endif //_TIMEZONE
853 //eof
854