1 /************************************************************************* 2 * Copyright (c) 1997-2010, 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 43 U_NAMESPACE_BEGIN 44 45 class StringEnumeration; 46 47 /** 48 * 49 * <code>TimeZone</code> represents a time zone offset, and also figures out daylight 50 * savings. 51 * 52 * <p> 53 * Typically, you get a <code>TimeZone</code> using <code>createDefault</code> 54 * which creates a <code>TimeZone</code> based on the time zone where the program 55 * is running. For example, for a program running in Japan, <code>createDefault</code> 56 * creates a <code>TimeZone</code> object based on Japanese Standard Time. 57 * 58 * <p> 59 * You can also get a <code>TimeZone</code> using <code>createTimeZone</code> along 60 * with a time zone ID. For instance, the time zone ID for the US Pacific 61 * Time zone is "America/Los_Angeles". So, you can get a Pacific Time <code>TimeZone</code> object 62 * with: 63 * \htmlonly<blockquote>\endhtmlonly 64 * <pre> 65 * TimeZone *tz = TimeZone::createTimeZone("America/Los_Angeles"); 66 * </pre> 67 * \htmlonly</blockquote>\endhtmlonly 68 * You can use <code>getAvailableIDs</code> method to iterate through 69 * all the supported time zone IDs. You can then choose a 70 * supported ID to get a <code>TimeZone</code>. 71 * If the time zone you want is not represented by one of the 72 * supported IDs, then you can create a custom time zone ID with 73 * the following syntax: 74 * 75 * \htmlonly<blockquote>\endhtmlonly 76 * <pre> 77 * GMT[+|-]hh[[:]mm] 78 * </pre> 79 * \htmlonly</blockquote>\endhtmlonly 80 * 81 * For example, you might specify GMT+14:00 as a custom 82 * time zone ID. The <code>TimeZone</code> that is returned 83 * when you specify a custom time zone ID does not include 84 * daylight savings time. 85 * 86 * TimeZone is an abstract class representing a time zone. A TimeZone is needed for 87 * Calendar to produce local time for a particular time zone. A TimeZone comprises 88 * three basic pieces of information: 89 * <ul> 90 * <li>A time zone offset; that, is the number of milliseconds to add or subtract 91 * from a time expressed in terms of GMT to convert it to the same time in that 92 * time zone (without taking daylight savings time into account).</li> 93 * <li>Logic necessary to take daylight savings time into account if daylight savings 94 * time is observed in that time zone (e.g., the days and hours on which daylight 95 * savings time begins and ends).</li> 96 * <li>An ID. This is a text string that uniquely identifies the time zone.</li> 97 * </ul> 98 * 99 * (Only the ID is actually implemented in TimeZone; subclasses of TimeZone may handle 100 * daylight savings time and GMT offset in different ways. Currently we only have one 101 * TimeZone subclass: SimpleTimeZone.) 102 * <P> 103 * The TimeZone class contains a static list containing a TimeZone object for every 104 * combination of GMT offset and daylight-savings time rules currently in use in the 105 * world, each with a unique ID. Each ID consists of a region (usually a continent or 106 * ocean) and a city in that region, separated by a slash, (for example, US Pacific 107 * Time is "America/Los_Angeles.") Because older versions of this class used 108 * three- or four-letter abbreviations instead, there is also a table that maps the older 109 * abbreviations to the newer ones (for example, "PST" maps to "America/Los_Angeles"). 110 * Anywhere the API requires an ID, you can use either form. 111 * <P> 112 * To create a new TimeZone, you call the factory function TimeZone::createTimeZone() 113 * and pass it a time zone ID. You can use the createEnumeration() function to 114 * obtain a list of all the time zone IDs recognized by createTimeZone(). 115 * <P> 116 * You can also use TimeZone::createDefault() to create a TimeZone. This function uses 117 * platform-specific APIs to produce a TimeZone for the time zone corresponding to 118 * the client's computer's physical location. For example, if you're in Japan (assuming 119 * your machine is set up correctly), TimeZone::createDefault() will return a TimeZone 120 * for Japanese Standard Time ("Asia/Tokyo"). 121 */ 122 class U_I18N_API TimeZone : public UObject { 123 public: 124 /** 125 * @stable ICU 2.0 126 */ 127 virtual ~TimeZone(); 128 129 /** 130 * The GMT time zone has a raw offset of zero and does not use daylight 131 * savings time. This is a commonly used time zone. 132 * @return the GMT time zone. 133 * @stable ICU 2.0 134 */ 135 static const TimeZone* U_EXPORT2 getGMT(void); 136 137 /** 138 * Creates a <code>TimeZone</code> for the given ID. 139 * @param ID the ID for a <code>TimeZone</code>, such as "America/Los_Angeles", 140 * or a custom ID such as "GMT-8:00". 141 * @return the specified <code>TimeZone</code>, or the GMT zone if the given ID 142 * cannot be understood. Return result guaranteed to be non-null. If you 143 * require that the specific zone asked for be returned, check the ID of the 144 * return result. 145 * @stable ICU 2.0 146 */ 147 static TimeZone* U_EXPORT2 createTimeZone(const UnicodeString& ID); 148 149 /** 150 * Returns an enumeration over all recognized time zone IDs. (i.e., 151 * all strings that createTimeZone() accepts) 152 * 153 * @return an enumeration object, owned by the caller. 154 * @stable ICU 2.4 155 */ 156 static StringEnumeration* U_EXPORT2 createEnumeration(); 157 158 /** 159 * Returns an enumeration over time zone IDs with a given raw 160 * offset from GMT. There may be several times zones with the 161 * same GMT offset that differ in the way they handle daylight 162 * savings time. For example, the state of Arizona doesn't 163 * observe daylight savings time. If you ask for the time zone 164 * IDs corresponding to GMT-7:00, you'll get back an enumeration 165 * over two time zone IDs: "America/Denver," which corresponds to 166 * Mountain Standard Time in the winter and Mountain Daylight Time 167 * in the summer, and "America/Phoenix", which corresponds to 168 * Mountain Standard Time year-round, even in the summer. 169 * 170 * @param rawOffset an offset from GMT in milliseconds, ignoring 171 * the effect of daylight savings time, if any 172 * @return an enumeration object, owned by the caller 173 * @stable ICU 2.4 174 */ 175 static StringEnumeration* U_EXPORT2 createEnumeration(int32_t rawOffset); 176 177 /** 178 * Returns an enumeration over time zone IDs associated with the 179 * given country. Some zones are affiliated with no country 180 * (e.g., "UTC"); these may also be retrieved, as a group. 181 * 182 * @param country The ISO 3166 two-letter country code, or NULL to 183 * retrieve zones not affiliated with any country. 184 * @return an enumeration object, owned by the caller 185 * @stable ICU 2.4 186 */ 187 static StringEnumeration* U_EXPORT2 createEnumeration(const char* country); 188 189 /** 190 * Returns the number of IDs in the equivalency group that 191 * includes the given ID. An equivalency group contains zones 192 * that have the same GMT offset and rules. 193 * 194 * <p>The returned count includes the given ID; it is always >= 1. 195 * The given ID must be a system time zone. If it is not, returns 196 * zero. 197 * @param id a system time zone ID 198 * @return the number of zones in the equivalency group containing 199 * 'id', or zero if 'id' is not a valid system ID 200 * @see #getEquivalentID 201 * @stable ICU 2.0 202 */ 203 static int32_t U_EXPORT2 countEquivalentIDs(const UnicodeString& id); 204 205 /** 206 * Returns an ID in the equivalency group that 207 * includes the given ID. An equivalency group contains zones 208 * that have the same GMT offset and rules. 209 * 210 * <p>The given index must be in the range 0..n-1, where n is the 211 * value returned by <code>countEquivalentIDs(id)</code>. For 212 * some value of 'index', the returned value will be equal to the 213 * given id. If the given id is not a valid system time zone, or 214 * if 'index' is out of range, then returns an empty string. 215 * @param id a system time zone ID 216 * @param index a value from 0 to n-1, where n is the value 217 * returned by <code>countEquivalentIDs(id)</code> 218 * @return the ID of the index-th zone in the equivalency group 219 * containing 'id', or an empty string if 'id' is not a valid 220 * system ID or 'index' is out of range 221 * @see #countEquivalentIDs 222 * @stable ICU 2.0 223 */ 224 static const UnicodeString U_EXPORT2 getEquivalentID(const UnicodeString& id, 225 int32_t index); 226 227 /** 228 * Creates a new copy of the default TimeZone for this host. Unless the default time 229 * zone has already been set using adoptDefault() or setDefault(), the default is 230 * determined by querying the system using methods in TPlatformUtilities. If the 231 * system routines fail, or if they specify a TimeZone or TimeZone offset which is not 232 * recognized, the TimeZone indicated by the ID kLastResortID is instantiated 233 * and made the default. 234 * 235 * @return A default TimeZone. Clients are responsible for deleting the time zone 236 * object returned. 237 * @stable ICU 2.0 238 */ 239 static TimeZone* U_EXPORT2 createDefault(void); 240 241 /** 242 * Sets the default time zone (i.e., what's returned by createDefault()) to be the 243 * specified time zone. If NULL is specified for the time zone, the default time 244 * zone is set to the default host time zone. This call adopts the TimeZone object 245 * passed in; the clent is no longer responsible for deleting it. 246 * 247 * @param zone A pointer to the new TimeZone object to use as the default. 248 * @stable ICU 2.0 249 */ 250 static void U_EXPORT2 adoptDefault(TimeZone* zone); 251 252 /** 253 * Same as adoptDefault(), except that the TimeZone object passed in is NOT adopted; 254 * the caller remains responsible for deleting it. 255 * 256 * @param zone The given timezone. 257 * @system 258 */ 259 static void U_EXPORT2 setDefault(const TimeZone& zone); 260 261 /** 262 * Returns the timezone data version currently used by ICU. 263 * @param status Output param to filled in with a success or an error. 264 * @return the version string, such as "2007f" 265 * @stable ICU 3.8 266 */ 267 static const char* U_EXPORT2 getTZDataVersion(UErrorCode& status); 268 269 /** 270 * Returns the canonical system timezone ID or the normalized 271 * custom time zone ID for the given time zone ID. 272 * @param id The input time zone ID to be canonicalized. 273 * @param canonicalID Receives the canonical system time zone ID 274 * or the custom time zone ID in normalized format. 275 * @param status Recevies the status. When the given time zone ID 276 * is neither a known system time zone ID nor a 277 * valid custom time zone ID, U_ILLEGAL_ARGUMENT_ERROR 278 * is set. 279 * @return A reference to the result. 280 * @stable ICU 4.0 281 */ 282 static UnicodeString& U_EXPORT2 getCanonicalID(const UnicodeString& id, 283 UnicodeString& canonicalID, UErrorCode& status); 284 285 /** 286 * Returns the canonical system time zone ID or the normalized 287 * custom time zone ID for the given time zone ID. 288 * @param id The input time zone ID to be canonicalized. 289 * @param canonicalID Receives the canonical system time zone ID 290 * or the custom time zone ID in normalized format. 291 * @param isSystemID Receives if the given ID is a known system 292 * time zone ID. 293 * @param status Recevies the status. When the given time zone ID 294 * is neither a known system time zone ID nor a 295 * valid custom time zone ID, U_ILLEGAL_ARGUMENT_ERROR 296 * is set. 297 * @return A reference to the result. 298 * @stable ICU 4.0 299 */ 300 static UnicodeString& U_EXPORT2 getCanonicalID(const UnicodeString& id, 301 UnicodeString& canonicalID, UBool& isSystemID, UErrorCode& status); 302 303 /** 304 * Returns true if the two TimeZones are equal. (The TimeZone version only compares 305 * IDs, but subclasses are expected to also compare the fields they add.) 306 * 307 * @param that The TimeZone object to be compared with. 308 * @return True if the given TimeZone is equal to this TimeZone; false 309 * otherwise. 310 * @stable ICU 2.0 311 */ 312 virtual UBool operator==(const TimeZone& that) const; 313 314 /** 315 * Returns true if the two TimeZones are NOT equal; that is, if operator==() returns 316 * false. 317 * 318 * @param that The TimeZone object to be compared with. 319 * @return True if the given TimeZone is not equal to this TimeZone; false 320 * otherwise. 321 * @stable ICU 2.0 322 */ 323 UBool operator!=(const TimeZone& that) const {return !operator==(that);} 324 325 /** 326 * Returns the TimeZone's adjusted GMT offset (i.e., the number of milliseconds to add 327 * to GMT to get local time in this time zone, taking daylight savings time into 328 * account) as of a particular reference date. The reference date is used to determine 329 * whether daylight savings time is in effect and needs to be figured into the offset 330 * that is returned (in other words, what is the adjusted GMT offset in this time zone 331 * at this particular date and time?). For the time zones produced by createTimeZone(), 332 * the reference data is specified according to the Gregorian calendar, and the date 333 * and time fields are local standard time. 334 * 335 * <p>Note: Don't call this method. Instead, call the getOffset(UDate...) overload, 336 * which returns both the raw and the DST offset for a given time. This method 337 * is retained only for backward compatibility. 338 * 339 * @param era The reference date's era 340 * @param year The reference date's year 341 * @param month The reference date's month (0-based; 0 is January) 342 * @param day The reference date's day-in-month (1-based) 343 * @param dayOfWeek The reference date's day-of-week (1-based; 1 is Sunday) 344 * @param millis The reference date's milliseconds in day, local standard time 345 * @param status Output param to filled in with a success or an error. 346 * @return The offset in milliseconds to add to GMT to get local time. 347 * @stable ICU 2.0 348 */ 349 virtual int32_t getOffset(uint8_t era, int32_t year, int32_t month, int32_t day, 350 uint8_t dayOfWeek, int32_t millis, UErrorCode& status) const = 0; 351 352 /** 353 * Gets the time zone offset, for current date, modified in case of 354 * daylight savings. This is the offset to add *to* UTC to get local time. 355 * 356 * <p>Note: Don't call this method. Instead, call the getOffset(UDate...) overload, 357 * which returns both the raw and the DST offset for a given time. This method 358 * is retained only for backward compatibility. 359 * 360 * @param era the era of the given date. 361 * @param year the year in the given date. 362 * @param month the month in the given date. 363 * Month is 0-based. e.g., 0 for January. 364 * @param day the day-in-month of the given date. 365 * @param dayOfWeek the day-of-week of the given date. 366 * @param milliseconds the millis in day in <em>standard</em> local time. 367 * @param monthLength the length of the given month in days. 368 * @param status Output param to filled in with a success or an error. 369 * @return the offset 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 milliseconds, 374 int32_t monthLength, UErrorCode& status) const = 0; 375 376 /** 377 * Returns the time zone raw and GMT offset for the given moment 378 * in time. Upon return, local-millis = GMT-millis + rawOffset + 379 * dstOffset. All computations are performed in the proleptic 380 * Gregorian calendar. The default implementation in the TimeZone 381 * class delegates to the 8-argument getOffset(). 382 * 383 * @param date moment in time for which to return offsets, in 384 * units of milliseconds from January 1, 1970 0:00 GMT, either GMT 385 * time or local wall time, depending on `local'. 386 * @param local if true, `date' is local wall time; otherwise it 387 * is in GMT time. 388 * @param rawOffset output parameter to receive the raw offset, that 389 * is, the offset not including DST adjustments 390 * @param dstOffset output parameter to receive the DST offset, 391 * that is, the offset to be added to `rawOffset' to obtain the 392 * total offset between local and GMT time. If DST is not in 393 * effect, this value is zero; otherwise it is a positive value, 394 * typically one hour. 395 * @param ec input-output error code 396 * 397 * @stable ICU 2.8 398 */ 399 virtual void getOffset(UDate date, UBool local, int32_t& rawOffset, 400 int32_t& dstOffset, UErrorCode& ec) const; 401 402 /** 403 * Sets the TimeZone's raw GMT offset (i.e., the number of milliseconds to add 404 * to GMT to get local time, before taking daylight savings time into account). 405 * 406 * @param offsetMillis The new raw GMT offset for this time zone. 407 * @stable ICU 2.0 408 */ 409 virtual void setRawOffset(int32_t offsetMillis) = 0; 410 411 /** 412 * Returns the TimeZone's raw GMT offset (i.e., the number of milliseconds to add 413 * to GMT to get local time, before taking daylight savings time into account). 414 * 415 * @return The TimeZone's raw GMT offset. 416 * @stable ICU 2.0 417 */ 418 virtual int32_t getRawOffset(void) const = 0; 419 420 /** 421 * Fills in "ID" with the TimeZone's ID. 422 * 423 * @param ID Receives this TimeZone's ID. 424 * @return A reference to 'ID' 425 * @stable ICU 2.0 426 */ 427 UnicodeString& getID(UnicodeString& ID) const; 428 429 /** 430 * Sets the TimeZone's ID to the specified value. This doesn't affect any other 431 * fields (for example, if you say< 432 * blockquote><pre> 433 * . TimeZone* foo = TimeZone::createTimeZone("America/New_York"); 434 * . foo.setID("America/Los_Angeles"); 435 * </pre>\htmlonly</blockquote>\endhtmlonly 436 * the time zone's GMT offset and daylight-savings rules don't change to those for 437 * Los Angeles. They're still those for New York. Only the ID has changed.) 438 * 439 * @param ID The new time zone ID. 440 * @stable ICU 2.0 441 */ 442 void setID(const UnicodeString& ID); 443 444 /** 445 * Enum for use with getDisplayName 446 * @stable ICU 2.4 447 */ 448 enum EDisplayType { 449 /** 450 * Selector for short display name 451 * @stable ICU 2.4 452 */ 453 SHORT = 1, 454 /** 455 * Selector for long display name 456 * @stable ICU 2.4 457 */ 458 LONG, 459 /** 460 * Selector for short generic display name 461 * @stable ICU 4.4 462 */ 463 SHORT_GENERIC, 464 /** 465 * Selector for long generic display name 466 * @stable ICU 4.4 467 */ 468 LONG_GENERIC, 469 /** 470 * Selector for short display name derived 471 * from time zone offset 472 * @stable ICU 4.4 473 */ 474 SHORT_GMT, 475 /** 476 * Selector for long display name derived 477 * from time zone offset 478 * @stable ICU 4.4 479 */ 480 LONG_GMT, 481 /** 482 * Selector for short display name derived 483 * from the time zone's fallback name 484 * @stable ICU 4.4 485 */ 486 SHORT_COMMONLY_USED, 487 /** 488 * Selector for long display name derived 489 * from the time zone's fallback name 490 * @stable ICU 4.4 491 */ 492 GENERIC_LOCATION 493 }; 494 495 /** 496 * Returns a name of this time zone suitable for presentation to the user 497 * in the default locale. 498 * This method returns the long name, not including daylight savings. 499 * If the display name is not available for the locale, 500 * then this method returns a string in the format 501 * <code>GMT[+-]hh:mm</code>. 502 * @param result the human-readable name of this time zone in the default locale. 503 * @return A reference to 'result'. 504 * @stable ICU 2.0 505 */ 506 UnicodeString& getDisplayName(UnicodeString& result) const; 507 508 /** 509 * Returns a name of this time zone suitable for presentation to the user 510 * in the specified locale. 511 * This method returns the long name, not including daylight savings. 512 * If the display name is not available for the locale, 513 * then this method returns a string in the format 514 * <code>GMT[+-]hh:mm</code>. 515 * @param locale the locale in which to supply the display name. 516 * @param result the human-readable name of this time zone in the given locale 517 * or in the default locale if the given locale is not recognized. 518 * @return A reference to 'result'. 519 * @stable ICU 2.0 520 */ 521 UnicodeString& getDisplayName(const Locale& locale, UnicodeString& result) const; 522 523 /** 524 * Returns a name of this time zone suitable for presentation to the user 525 * in the default locale. 526 * If the display name is not available for the locale, 527 * then this method returns a string in the format 528 * <code>GMT[+-]hh:mm</code>. 529 * @param daylight if true, return the daylight savings name. 530 * @param style 531 * @param result the human-readable name of this time zone in the default locale. 532 * @return A reference to 'result'. 533 * @stable ICU 2.0 534 */ 535 UnicodeString& getDisplayName(UBool daylight, EDisplayType style, UnicodeString& result) const; 536 537 /** 538 * Returns a name of this time zone suitable for presentation to the user 539 * in the specified locale. 540 * If the display name is not available for the locale, 541 * then this method returns a string in the format 542 * <code>GMT[+-]hh:mm</code>. 543 * @param daylight if true, return the daylight savings name. 544 * @param style 545 * @param locale the locale in which to supply the display name. 546 * @param result the human-readable name of this time zone in the given locale 547 * or in the default locale if the given locale is not recognized. 548 * @return A refence to 'result'. 549 * @stable ICU 2.0 550 */ 551 UnicodeString& getDisplayName(UBool daylight, EDisplayType style, const Locale& locale, UnicodeString& result) const; 552 553 /** 554 * Queries if this time zone uses daylight savings time. 555 * @return true if this time zone uses daylight savings time, 556 * false, otherwise. 557 * @stable ICU 2.0 558 */ 559 virtual UBool useDaylightTime(void) const = 0; 560 561 /** 562 * Queries if the given date is in daylight savings time in 563 * this time zone. 564 * This method is wasteful since it creates a new GregorianCalendar and 565 * deletes it each time it is called. This is a deprecated method 566 * and provided only for Java compatibility. 567 * 568 * @param date the given UDate. 569 * @param status Output param filled in with success/error code. 570 * @return true if the given date is in daylight savings time, 571 * false, otherwise. 572 * @deprecated ICU 2.4. Use Calendar::inDaylightTime() instead. 573 */ 574 virtual UBool inDaylightTime(UDate date, UErrorCode& status) const = 0; 575 576 /** 577 * Returns true if this zone has the same rule and offset as another zone. 578 * That is, if this zone differs only in ID, if at all. 579 * @param other the <code>TimeZone</code> object to be compared with 580 * @return true if the given zone is the same as this one, 581 * with the possible exception of the ID 582 * @stable ICU 2.0 583 */ 584 virtual UBool hasSameRules(const TimeZone& other) const; 585 586 /** 587 * Clones TimeZone objects polymorphically. Clients are responsible for deleting 588 * the TimeZone object cloned. 589 * 590 * @return A new copy of this TimeZone object. 591 * @stable ICU 2.0 592 */ 593 virtual TimeZone* clone(void) const = 0; 594 595 /** 596 * Return the class ID for this class. This is useful only for 597 * comparing to a return value from getDynamicClassID(). 598 * @return The class ID for all objects of this class. 599 * @stable ICU 2.0 600 */ 601 static UClassID U_EXPORT2 getStaticClassID(void); 602 603 /** 604 * Returns a unique class ID POLYMORPHICALLY. This method is to 605 * implement a simple version of RTTI, since not all C++ compilers support genuine 606 * RTTI. Polymorphic operator==() and clone() methods call this method. 607 * <P> 608 * Concrete subclasses of TimeZone must use the UOBJECT_DEFINE_RTTI_IMPLEMENTATION 609 * macro from uobject.h in their implementation to provide correct RTTI information. 610 * @return The class ID for this object. All objects of a given class have the 611 * same class ID. Objects of other classes have different class IDs. 612 * @stable ICU 2.0 613 */ 614 virtual UClassID getDynamicClassID(void) const = 0; 615 616 /** 617 * Returns the amount of time to be added to local standard time 618 * to get local wall clock time. 619 * <p> 620 * The default implementation always returns 3600000 milliseconds 621 * (i.e., one hour) if this time zone observes Daylight Saving 622 * Time. Otherwise, 0 (zero) is returned. 623 * <p> 624 * If an underlying TimeZone implementation subclass supports 625 * historical Daylight Saving Time changes, this method returns 626 * the known latest daylight saving value. 627 * 628 * @return the amount of saving time in milliseconds 629 * @stable ICU 3.6 630 */ 631 virtual int32_t getDSTSavings() const; 632 633 protected: 634 635 /** 636 * Default constructor. ID is initialized to the empty string. 637 * @stable ICU 2.0 638 */ 639 TimeZone(); 640 641 /** 642 * Construct a TimeZone with a given ID. 643 * @param id a system time zone ID 644 * @stable ICU 2.0 645 */ 646 TimeZone(const UnicodeString &id); 647 648 /** 649 * Copy constructor. 650 * @param source the object to be copied. 651 * @stable ICU 2.0 652 */ 653 TimeZone(const TimeZone& source); 654 655 /** 656 * Default assignment operator. 657 * @param right the object to be copied. 658 * @stable ICU 2.0 659 */ 660 TimeZone& operator=(const TimeZone& right); 661 662 /** 663 * Utility function. For internally loading rule data. 664 * @param top Top resource bundle for tz data 665 * @param ruleid ID of rule to load 666 * @param oldbundle Old bundle to reuse or NULL 667 * @param status Status parameter 668 * @return either a new bundle or *oldbundle 669 * @internal 670 */ 671 static UResourceBundle* loadRule(const UResourceBundle* top, const UnicodeString& ruleid, UResourceBundle* oldbundle, UErrorCode&status); 672 673 private: 674 friend class ZoneMeta; 675 676 677 static TimeZone* createCustomTimeZone(const UnicodeString&); // Creates a time zone based on the string. 678 679 /** 680 * Resolve a link in Olson tzdata. When the given id is known and it's not a link, 681 * the id itself is returned. When the given id is known and it is a link, then 682 * dereferenced zone id is returned. When the given id is unknown, then it returns 683 * NULL. 684 * @param id zone id string 685 * @return the dereferenced zone or NULL 686 */ 687 static const UChar* dereferOlsonLink(const UnicodeString& id); 688 689 /** 690 * Returns the region code associated with the given zone. 691 * @param id zone id string 692 * @return the region associated with the given zone 693 */ 694 static const UChar* getRegion(const UnicodeString& id); 695 696 /** 697 * Parses the given custom time zone identifier 698 * @param id id A string of the form GMT[+-]hh:mm, GMT[+-]hhmm, or 699 * GMT[+-]hh. 700 * @param sign Receves parsed sign, 1 for positive, -1 for negative. 701 * @param hour Receives parsed hour field 702 * @param minute Receives parsed minute field 703 * @param second Receives parsed second field 704 * @return Returns TRUE when the given custom id is valid. 705 */ 706 static UBool parseCustomID(const UnicodeString& id, int32_t& sign, int32_t& hour, 707 int32_t& min, int32_t& sec); 708 709 /** 710 * Parse a custom time zone identifier and return the normalized 711 * custom time zone identifier for the given custom id string. 712 * @param id a string of the form GMT[+-]hh:mm, GMT[+-]hhmm, or 713 * GMT[+-]hh. 714 * @param normalized Receives the normalized custom ID 715 * @param status Receives the status. When the input ID string is invalid, 716 * U_ILLEGAL_ARGUMENT_ERROR is set. 717 * @return The normalized custom id string. 718 */ 719 static UnicodeString& getCustomID(const UnicodeString& id, UnicodeString& normalized, 720 UErrorCode& status); 721 722 /** 723 * Returns the normalized custome time zone ID for the given offset fields. 724 * @param hour offset hours 725 * @param min offset minutes 726 * @param sec offset seconds 727 * @param netative sign of the offset, TRUE for negative offset. 728 * @param id Receves the format result (normalized custom ID) 729 * @return The reference to id 730 */ 731 static UnicodeString& formatCustomID(int32_t hour, int32_t min, int32_t sec, 732 UBool negative, UnicodeString& id); 733 734 /** 735 * Responsible for setting up DEFAULT_ZONE. Uses routines in TPlatformUtilities 736 * (i.e., platform-specific calls) to get the current system time zone. Failing 737 * that, uses the platform-specific default time zone. Failing that, uses GMT. 738 */ 739 static void initDefault(void); 740 741 // See source file for documentation 742 /** 743 * Lookup the given name in our system zone table. If found, 744 * instantiate a new zone of that name and return it. If not 745 * found, return 0. 746 * @param name tthe given name of a system time zone. 747 * @return the TimeZone indicated by the 'name'. 748 */ 749 static TimeZone* createSystemTimeZone(const UnicodeString& name); 750 751 UnicodeString fID; // this time zone's ID 752 753 }; 754 755 756 // ------------------------------------- 757 758 inline UnicodeString& 759 TimeZone::getID(UnicodeString& ID) const 760 { 761 ID = fID; 762 return ID; 763 } 764 765 // ------------------------------------- 766 767 inline void 768 TimeZone::setID(const UnicodeString& ID) 769 { 770 fID = ID; 771 } 772 U_NAMESPACE_END 773 774 #endif /* #if !UCONFIG_NO_FORMATTING */ 775 776 #endif //_TIMEZONE 777 //eof 778
