1 /* 2 ******************************************************************************** 3 * Copyright (C) 1997-2010, International Business Machines 4 * Corporation and others. All Rights Reserved. 5 ******************************************************************************** 6 * 7 * File brkiter.h 8 * 9 * Modification History: 10 * 11 * Date Name Description 12 * 02/18/97 aliu Added typedef for TextCount. Made DONE const. 13 * 05/07/97 aliu Fixed DLL declaration. 14 * 07/09/97 jfitz Renamed BreakIterator and interface synced with JDK 15 * 08/11/98 helena Sync-up JDK1.2. 16 * 01/13/2000 helena Added UErrorCode parameter to createXXXInstance methods. 17 ******************************************************************************** 18 */ 19 20 #ifndef BRKITER_H 21 #define BRKITER_H 22 23 #include "unicode/utypes.h" 24 25 /** 26 * \file 27 * \brief C++ API: Break Iterator. 28 */ 29 30 #if UCONFIG_NO_BREAK_ITERATION 31 32 U_NAMESPACE_BEGIN 33 34 /* 35 * Allow the declaration of APIs with pointers to BreakIterator 36 * even when break iteration is removed from the build. 37 */ 38 class BreakIterator; 39 40 U_NAMESPACE_END 41 42 #else 43 44 #include "unicode/uobject.h" 45 #include "unicode/unistr.h" 46 #include "unicode/chariter.h" 47 #include "unicode/locid.h" 48 #include "unicode/ubrk.h" 49 #include "unicode/strenum.h" 50 #include "unicode/utext.h" 51 #include "unicode/umisc.h" 52 53 U_NAMESPACE_BEGIN 54 55 /** 56 * The BreakIterator class implements methods for finding the location 57 * of boundaries in text. BreakIterator is an abstract base class. 58 * Instances of BreakIterator maintain a current position and scan over 59 * text returning the index of characters where boundaries occur. 60 * <p> 61 * Line boundary analysis determines where a text string can be broken 62 * when line-wrapping. The mechanism correctly handles punctuation and 63 * hyphenated words. 64 * <p> 65 * Sentence boundary analysis allows selection with correct 66 * interpretation of periods within numbers and abbreviations, and 67 * trailing punctuation marks such as quotation marks and parentheses. 68 * <p> 69 * Word boundary analysis is used by search and replace functions, as 70 * well as within text editing applications that allow the user to 71 * select words with a double click. Word selection provides correct 72 * interpretation of punctuation marks within and following 73 * words. Characters that are not part of a word, such as symbols or 74 * punctuation marks, have word-breaks on both sides. 75 * <p> 76 * Character boundary analysis allows users to interact with 77 * characters as they expect to, for example, when moving the cursor 78 * through a text string. Character boundary analysis provides correct 79 * navigation of through character strings, regardless of how the 80 * character is stored. For example, an accented character might be 81 * stored as a base character and a diacritical mark. What users 82 * consider to be a character can differ between languages. 83 * <p> 84 * The text boundary positions are found according to the rules 85 * described in Unicode Standard Annex #29, Text Boundaries, and 86 * Unicode Standard Annex #14, Line Breaking Properties. These 87 * are available at http://www.unicode.org/reports/tr14/ and 88 * http://www.unicode.org/reports/tr29/. 89 * <p> 90 * In addition to the C++ API defined in this header file, a 91 * plain C API with equivalent functionality is defined in the 92 * file ubrk.h 93 * <p> 94 * Code snippets illustrating the use of the Break Iterator APIs 95 * are available in the ICU User Guide, 96 * http://icu-project.org/userguide/boundaryAnalysis.html 97 * and in the sample program icu/source/samples/break/break.cpp 98 * 99 */ 100 class U_COMMON_API BreakIterator : public UObject { 101 public: 102 /** 103 * destructor 104 * @stable ICU 2.0 105 */ 106 virtual ~BreakIterator(); 107 108 /** 109 * Return true if another object is semantically equal to this 110 * one. The other object should be an instance of the same subclass of 111 * BreakIterator. Objects of different subclasses are considered 112 * unequal. 113 * <P> 114 * Return true if this BreakIterator is at the same position in the 115 * same text, and is the same class and type (word, line, etc.) of 116 * BreakIterator, as the argument. Text is considered the same if 117 * it contains the same characters, it need not be the same 118 * object, and styles are not considered. 119 * @stable ICU 2.0 120 */ 121 virtual UBool operator==(const BreakIterator&) const = 0; 122 123 /** 124 * Returns the complement of the result of operator== 125 * @param rhs The BreakIterator to be compared for inequality 126 * @return the complement of the result of operator== 127 * @stable ICU 2.0 128 */ 129 UBool operator!=(const BreakIterator& rhs) const { return !operator==(rhs); } 130 131 /** 132 * Return a polymorphic copy of this object. This is an abstract 133 * method which subclasses implement. 134 * @stable ICU 2.0 135 */ 136 virtual BreakIterator* clone(void) const = 0; 137 138 /** 139 * Return a polymorphic class ID for this object. Different subclasses 140 * will return distinct unequal values. 141 * @stable ICU 2.0 142 */ 143 virtual UClassID getDynamicClassID(void) const = 0; 144 145 /** 146 * Return a CharacterIterator over the text being analyzed. 147 * @stable ICU 2.0 148 */ 149 virtual CharacterIterator& getText(void) const = 0; 150 151 152 /** 153 * Get a UText for the text being analyzed. 154 * The returned UText is a shallow clone of the UText used internally 155 * by the break iterator implementation. It can safely be used to 156 * access the text without impacting any break iterator operations, 157 * but the underlying text itself must not be altered. 158 * 159 * @param fillIn A UText to be filled in. If NULL, a new UText will be 160 * allocated to hold the result. 161 * @param status receives any error codes. 162 * @return The current UText for this break iterator. If an input 163 * UText was provided, it will always be returned. 164 * @stable ICU 3.4 165 */ 166 virtual UText *getUText(UText *fillIn, UErrorCode &status) const = 0; 167 168 /** 169 * Change the text over which this operates. The text boundary is 170 * reset to the start. 171 * @param text The UnicodeString used to change the text. 172 * @stable ICU 2.0 173 */ 174 virtual void setText(const UnicodeString &text) = 0; 175 176 /** 177 * Reset the break iterator to operate over the text represented by 178 * the UText. The iterator position is reset to the start. 179 * 180 * This function makes a shallow clone of the supplied UText. This means 181 * that the caller is free to immediately close or otherwise reuse the 182 * Utext that was passed as a parameter, but that the underlying text itself 183 * must not be altered while being referenced by the break iterator. 184 * 185 * @param text The UText used to change the text. 186 * @param status receives any error codes. 187 * @stable ICU 3.4 188 */ 189 virtual void setText(UText *text, UErrorCode &status) = 0; 190 191 /** 192 * Change the text over which this operates. The text boundary is 193 * reset to the start. 194 * Note that setText(UText *) provides similar functionality to this function, 195 * and is more efficient. 196 * @param it The CharacterIterator used to change the text. 197 * @stable ICU 2.0 198 */ 199 virtual void adoptText(CharacterIterator* it) = 0; 200 201 enum { 202 /** 203 * DONE is returned by previous() and next() after all valid 204 * boundaries have been returned. 205 * @stable ICU 2.0 206 */ 207 DONE = (int32_t)-1 208 }; 209 210 /** 211 * Return the index of the first character in the text being scanned. 212 * @stable ICU 2.0 213 */ 214 virtual int32_t first(void) = 0; 215 216 /** 217 * Return the index immediately BEYOND the last character in the text being scanned. 218 * @stable ICU 2.0 219 */ 220 virtual int32_t last(void) = 0; 221 222 /** 223 * Return the boundary preceding the current boundary. 224 * @return The character index of the previous text boundary or DONE if all 225 * boundaries have been returned. 226 * @stable ICU 2.0 227 */ 228 virtual int32_t previous(void) = 0; 229 230 /** 231 * Return the boundary following the current boundary. 232 * @return The character index of the next text boundary or DONE if all 233 * boundaries have been returned. 234 * @stable ICU 2.0 235 */ 236 virtual int32_t next(void) = 0; 237 238 /** 239 * Return character index of the current interator position within the text. 240 * @return The boundary most recently returned. 241 * @stable ICU 2.0 242 */ 243 virtual int32_t current(void) const = 0; 244 245 /** 246 * Return the first boundary following the specified offset. 247 * The value returned is always greater than the offset or 248 * the value BreakIterator.DONE 249 * @param offset the offset to begin scanning. 250 * @return The first boundary after the specified offset. 251 * @stable ICU 2.0 252 */ 253 virtual int32_t following(int32_t offset) = 0; 254 255 /** 256 * Return the first boundary preceding the specified offset. 257 * The value returned is always smaller than the offset or 258 * the value BreakIterator.DONE 259 * @param offset the offset to begin scanning. 260 * @return The first boundary before the specified offset. 261 * @stable ICU 2.0 262 */ 263 virtual int32_t preceding(int32_t offset) = 0; 264 265 /** 266 * Return true if the specfied position is a boundary position. 267 * As a side effect, the current position of the iterator is set 268 * to the first boundary position at or following the specified offset. 269 * @param offset the offset to check. 270 * @return True if "offset" is a boundary position. 271 * @stable ICU 2.0 272 */ 273 virtual UBool isBoundary(int32_t offset) = 0; 274 275 /** 276 * Return the nth boundary from the current boundary 277 * @param n which boundary to return. A value of 0 278 * does nothing. Negative values move to previous boundaries 279 * and positive values move to later boundaries. 280 * @return The index of the nth boundary from the current position, or 281 * DONE if there are fewer than |n| boundaries in the specfied direction. 282 * @stable ICU 2.0 283 */ 284 virtual int32_t next(int32_t n) = 0; 285 286 /** 287 * Create BreakIterator for word-breaks using the given locale. 288 * Returns an instance of a BreakIterator implementing word breaks. 289 * WordBreak is useful for word selection (ex. double click) 290 * @param where the locale. 291 * @param status the error code 292 * @return A BreakIterator for word-breaks. The UErrorCode& status 293 * parameter is used to return status information to the user. 294 * To check whether the construction succeeded or not, you should check 295 * the value of U_SUCCESS(err). If you wish more detailed information, you 296 * can check for informational error results which still indicate success. 297 * U_USING_FALLBACK_WARNING indicates that a fall back locale was used. For 298 * example, 'de_CH' was requested, but nothing was found there, so 'de' was 299 * used. U_USING_DEFAULT_WARNING indicates that the default locale data was 300 * used; neither the requested locale nor any of its fall back locales 301 * could be found. 302 * The caller owns the returned object and is responsible for deleting it. 303 * @stable ICU 2.0 304 */ 305 static BreakIterator* U_EXPORT2 306 createWordInstance(const Locale& where, UErrorCode& status); 307 308 /** 309 * Create BreakIterator for line-breaks using specified locale. 310 * Returns an instance of a BreakIterator implementing line breaks. Line 311 * breaks are logically possible line breaks, actual line breaks are 312 * usually determined based on display width. 313 * LineBreak is useful for word wrapping text. 314 * @param where the locale. 315 * @param status The error code. 316 * @return A BreakIterator for line-breaks. The UErrorCode& status 317 * parameter is used to return status information to the user. 318 * To check whether the construction succeeded or not, you should check 319 * the value of U_SUCCESS(err). If you wish more detailed information, you 320 * can check for informational error results which still indicate success. 321 * U_USING_FALLBACK_WARNING indicates that a fall back locale was used. For 322 * example, 'de_CH' was requested, but nothing was found there, so 'de' was 323 * used. U_USING_DEFAULT_WARNING indicates that the default locale data was 324 * used; neither the requested locale nor any of its fall back locales 325 * could be found. 326 * The caller owns the returned object and is responsible for deleting it. 327 * @stable ICU 2.0 328 */ 329 static BreakIterator* U_EXPORT2 330 createLineInstance(const Locale& where, UErrorCode& status); 331 332 /** 333 * Create BreakIterator for character-breaks using specified locale 334 * Returns an instance of a BreakIterator implementing character breaks. 335 * Character breaks are boundaries of combining character sequences. 336 * @param where the locale. 337 * @param status The error code. 338 * @return A BreakIterator for character-breaks. The UErrorCode& status 339 * parameter is used to return status information to the user. 340 * To check whether the construction succeeded or not, you should check 341 * the value of U_SUCCESS(err). If you wish more detailed information, you 342 * can check for informational error results which still indicate success. 343 * U_USING_FALLBACK_WARNING indicates that a fall back locale was used. For 344 * example, 'de_CH' was requested, but nothing was found there, so 'de' was 345 * used. U_USING_DEFAULT_WARNING indicates that the default locale data was 346 * used; neither the requested locale nor any of its fall back locales 347 * could be found. 348 * The caller owns the returned object and is responsible for deleting it. 349 * @stable ICU 2.0 350 */ 351 static BreakIterator* U_EXPORT2 352 createCharacterInstance(const Locale& where, UErrorCode& status); 353 354 /** 355 * Create BreakIterator for sentence-breaks using specified locale 356 * Returns an instance of a BreakIterator implementing sentence breaks. 357 * @param where the locale. 358 * @param status The error code. 359 * @return A BreakIterator for sentence-breaks. The UErrorCode& status 360 * parameter is used to return status information to the user. 361 * To check whether the construction succeeded or not, you should check 362 * the value of U_SUCCESS(err). If you wish more detailed information, you 363 * can check for informational error results which still indicate success. 364 * U_USING_FALLBACK_WARNING indicates that a fall back locale was used. For 365 * example, 'de_CH' was requested, but nothing was found there, so 'de' was 366 * used. U_USING_DEFAULT_WARNING indicates that the default locale data was 367 * used; neither the requested locale nor any of its fall back locales 368 * could be found. 369 * The caller owns the returned object and is responsible for deleting it. 370 * @stable ICU 2.0 371 */ 372 static BreakIterator* U_EXPORT2 373 createSentenceInstance(const Locale& where, UErrorCode& status); 374 375 /** 376 * Create BreakIterator for title-casing breaks using the specified locale 377 * Returns an instance of a BreakIterator implementing title breaks. 378 * The iterator returned locates title boundaries as described for 379 * Unicode 3.2 only. For Unicode 4.0 and above title boundary iteration, 380 * please use Word Boundary iterator.{@link #createWordInstance } 381 * 382 * @param where the locale. 383 * @param status The error code. 384 * @return A BreakIterator for title-breaks. The UErrorCode& status 385 * parameter is used to return status information to the user. 386 * To check whether the construction succeeded or not, you should check 387 * the value of U_SUCCESS(err). If you wish more detailed information, you 388 * can check for informational error results which still indicate success. 389 * U_USING_FALLBACK_WARNING indicates that a fall back locale was used. For 390 * example, 'de_CH' was requested, but nothing was found there, so 'de' was 391 * used. U_USING_DEFAULT_WARNING indicates that the default locale data was 392 * used; neither the requested locale nor any of its fall back locales 393 * could be found. 394 * The caller owns the returned object and is responsible for deleting it. 395 * @stable ICU 2.1 396 */ 397 static BreakIterator* U_EXPORT2 398 createTitleInstance(const Locale& where, UErrorCode& status); 399 400 /** 401 * Get the set of Locales for which TextBoundaries are installed. 402 * <p><b>Note:</b> this will not return locales added through the register 403 * call. To see the registered locales too, use the getAvailableLocales 404 * function that returns a StringEnumeration object </p> 405 * @param count the output parameter of number of elements in the locale list 406 * @return available locales 407 * @stable ICU 2.0 408 */ 409 static const Locale* U_EXPORT2 getAvailableLocales(int32_t& count); 410 411 /** 412 * Get name of the object for the desired Locale, in the desired langauge. 413 * @param objectLocale must be from getAvailableLocales. 414 * @param displayLocale specifies the desired locale for output. 415 * @param name the fill-in parameter of the return value 416 * Uses best match. 417 * @return user-displayable name 418 * @stable ICU 2.0 419 */ 420 static UnicodeString& U_EXPORT2 getDisplayName(const Locale& objectLocale, 421 const Locale& displayLocale, 422 UnicodeString& name); 423 424 /** 425 * Get name of the object for the desired Locale, in the langauge of the 426 * default locale. 427 * @param objectLocale must be from getMatchingLocales 428 * @param name the fill-in parameter of the return value 429 * @return user-displayable name 430 * @stable ICU 2.0 431 */ 432 static UnicodeString& U_EXPORT2 getDisplayName(const Locale& objectLocale, 433 UnicodeString& name); 434 435 /** 436 * Thread safe client-buffer-based cloning operation 437 * Do NOT call delete on a safeclone, since 'new' is not used to create it. 438 * @param stackBuffer user allocated space for the new clone. If NULL new memory will be allocated. 439 * If buffer is not large enough, new memory will be allocated. 440 * @param BufferSize reference to size of allocated space. 441 * If BufferSize == 0, a sufficient size for use in cloning will 442 * be returned ('pre-flighting') 443 * If BufferSize is not enough for a stack-based safe clone, 444 * new memory will be allocated. 445 * @param status to indicate whether the operation went on smoothly or there were errors 446 * An informational status value, U_SAFECLONE_ALLOCATED_ERROR, is used if any allocations were 447 * necessary. 448 * @return pointer to the new clone 449 * 450 * @stable ICU 2.0 451 */ 452 virtual BreakIterator * createBufferClone(void *stackBuffer, 453 int32_t &BufferSize, 454 UErrorCode &status) = 0; 455 456 /** 457 * Determine whether the BreakIterator was created in user memory by 458 * createBufferClone(), and thus should not be deleted. Such objects 459 * must be closed by an explicit call to the destructor (not delete). 460 * @stable ICU 2.0 461 */ 462 inline UBool isBufferClone(void); 463 464 #if !UCONFIG_NO_SERVICE 465 /** 466 * Register a new break iterator of the indicated kind, to use in the given locale. 467 * The break iterator will be adopted. Clones of the iterator will be returned 468 * if a request for a break iterator of the given kind matches or falls back to 469 * this locale. 470 * @param toAdopt the BreakIterator instance to be adopted 471 * @param locale the Locale for which this instance is to be registered 472 * @param kind the type of iterator for which this instance is to be registered 473 * @param status the in/out status code, no special meanings are assigned 474 * @return a registry key that can be used to unregister this instance 475 * @stable ICU 2.4 476 */ 477 static URegistryKey U_EXPORT2 registerInstance(BreakIterator* toAdopt, 478 const Locale& locale, 479 UBreakIteratorType kind, 480 UErrorCode& status); 481 482 /** 483 * Unregister a previously-registered BreakIterator using the key returned from the 484 * register call. Key becomes invalid after a successful call and should not be used again. 485 * The BreakIterator corresponding to the key will be deleted. 486 * @param key the registry key returned by a previous call to registerInstance 487 * @param status the in/out status code, no special meanings are assigned 488 * @return TRUE if the iterator for the key was successfully unregistered 489 * @stable ICU 2.4 490 */ 491 static UBool U_EXPORT2 unregister(URegistryKey key, UErrorCode& status); 492 493 /** 494 * Return a StringEnumeration over the locales available at the time of the call, 495 * including registered locales. 496 * @return a StringEnumeration over the locales available at the time of the call 497 * @stable ICU 2.4 498 */ 499 static StringEnumeration* U_EXPORT2 getAvailableLocales(void); 500 #endif 501 502 /** 503 * Returns the locale for this break iterator. Two flavors are available: valid and 504 * actual locale. 505 * @stable ICU 2.8 506 */ 507 Locale getLocale(ULocDataLocaleType type, UErrorCode& status) const; 508 509 /** Get the locale for this break iterator object. You can choose between valid and actual locale. 510 * @param type type of the locale we're looking for (valid or actual) 511 * @param status error code for the operation 512 * @return the locale 513 * @internal 514 */ 515 const char *getLocaleID(ULocDataLocaleType type, UErrorCode& status) const; 516 517 private: 518 static BreakIterator* buildInstance(const Locale& loc, const char *type, int32_t kind, UErrorCode& status); 519 static BreakIterator* createInstance(const Locale& loc, int32_t kind, UErrorCode& status); 520 static BreakIterator* makeInstance(const Locale& loc, int32_t kind, UErrorCode& status); 521 522 friend class ICUBreakIteratorFactory; 523 friend class ICUBreakIteratorService; 524 525 protected: 526 /** @internal */ 527 BreakIterator(); 528 /** @internal */ 529 UBool fBufferClone; 530 /** @internal */ 531 BreakIterator (const BreakIterator &other) : UObject(other), fBufferClone(FALSE) {} 532 533 private: 534 535 /** @internal */ 536 char actualLocale[ULOC_FULLNAME_CAPACITY]; 537 char validLocale[ULOC_FULLNAME_CAPACITY]; 538 539 /** 540 * The assignment operator has no real implementation. 541 * It's provided to make the compiler happy. Do not call. 542 */ 543 BreakIterator& operator=(const BreakIterator&); 544 }; 545 546 inline UBool BreakIterator::isBufferClone() 547 { 548 return fBufferClone; 549 } 550 551 U_NAMESPACE_END 552 553 #endif /* #if !UCONFIG_NO_BREAK_ITERATION */ 554 555 #endif // _BRKITER 556 //eof 557 558