icuSources/i18n/unicode/reldatefmt.h

   1 // © 2016 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html
   3 /*
   4 *****************************************************************************
   5 * Copyright (C) 2014-2016, International Business Machines Corporation and
   6 * others.
   7 * All Rights Reserved.
   8 *****************************************************************************
   9 *
  10 * File RELDATEFMT.H
  11 *****************************************************************************
  12 */
  13
  14 #ifndef __RELDATEFMT_H
  15 #define __RELDATEFMT_H
  16
  17 #include "unicode/utypes.h"
  18 #include "unicode/uobject.h"
  19 #include "unicode/udisplaycontext.h"
  20 #include "unicode/ureldatefmt.h"
  21 #include "unicode/locid.h"
  22 #include "unicode/formattedvalue.h"
  23
  24 /**
  25  * \file
  26  * \brief C++ API: Formats relative dates such as "1 day ago" or "tomorrow"
  27  */
  28
  29 #if !UCONFIG_NO_FORMATTING
  30
  31 /**
  32  * Represents the unit for formatting a relative date. e.g "in 5 days"
  33  * or "in 3 months"
  34  * @stable ICU 53
  35  */
  36 typedef enum UDateRelativeUnit {
  37
  38     /**
  39      * Seconds
  40      * @stable ICU 53
  41      */
  42     UDAT_RELATIVE_SECONDS,
  43
  44     /**
  45      * Minutes
  46      * @stable ICU 53
  47      */
  48     UDAT_RELATIVE_MINUTES,
  49
  50     /**
  51      * Hours
  52      * @stable ICU 53
  53      */
  54     UDAT_RELATIVE_HOURS,
  55
  56     /**
  57      * Days
  58      * @stable ICU 53
  59      */
  60     UDAT_RELATIVE_DAYS,
  61
  62     /**
  63      * Weeks
  64      * @stable ICU 53
  65      */
  66     UDAT_RELATIVE_WEEKS,
  67
  68     /**
  69      * Months
  70      * @stable ICU 53
  71      */
  72     UDAT_RELATIVE_MONTHS,
  73
  74     /**
  75      * Years
  76      * @stable ICU 53
  77      */
  78     UDAT_RELATIVE_YEARS,
  79
  80 #ifndef U_HIDE_DEPRECATED_API
  81     /**
  82      * One more than the highest normal UDateRelativeUnit value.
  83      * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
  84      */
  85     UDAT_RELATIVE_UNIT_COUNT
  86 #endif  // U_HIDE_DEPRECATED_API
  87 } UDateRelativeUnit;
  88
  89 /**
  90  * Represents an absolute unit.
  91  * @stable ICU 53
  92  */
  93 typedef enum UDateAbsoluteUnit {
  94
  95     // Days of week have to remain together and in order from Sunday to
  96     // Saturday.
  97     /**
  98      * Sunday
  99      * @stable ICU 53
 100      */
 101     UDAT_ABSOLUTE_SUNDAY,
 102
 103     /**
 104      * Monday
 105      * @stable ICU 53
 106      */
 107     UDAT_ABSOLUTE_MONDAY,
 108
 109     /**
 110      * Tuesday
 111      * @stable ICU 53
 112      */
 113     UDAT_ABSOLUTE_TUESDAY,
 114
 115     /**
 116      * Wednesday
 117      * @stable ICU 53
 118      */
 119     UDAT_ABSOLUTE_WEDNESDAY,
 120
 121     /**
 122      * Thursday
 123      * @stable ICU 53
 124      */
 125     UDAT_ABSOLUTE_THURSDAY,
 126
 127     /**
 128      * Friday
 129      * @stable ICU 53
 130      */
 131     UDAT_ABSOLUTE_FRIDAY,
 132
 133     /**
 134      * Saturday
 135      * @stable ICU 53
 136      */
 137     UDAT_ABSOLUTE_SATURDAY,
 138
 139     /**
 140      * Day
 141      * @stable ICU 53
 142      */
 143     UDAT_ABSOLUTE_DAY,
 144
 145     /**
 146      * Week
 147      * @stable ICU 53
 148      */
 149     UDAT_ABSOLUTE_WEEK,
 150
 151     /**
 152      * Month
 153      * @stable ICU 53
 154      */
 155     UDAT_ABSOLUTE_MONTH,
 156
 157     /**
 158      * Year
 159      * @stable ICU 53
 160      */
 161     UDAT_ABSOLUTE_YEAR,
 162
 163     /**
 164      * Now
 165      * @stable ICU 53
 166      */
 167     UDAT_ABSOLUTE_NOW,
 168
 169 #ifndef U_HIDE_DRAFT_API
 170     /**
 171      * Quarter
 172      * @draft ICU 63
 173      */
 174     UDAT_ABSOLUTE_QUARTER,
 175 #endif // U_HIDE_DRAFT_API
 176
 177 #ifndef U_HIDE_DEPRECATED_API
 178     /**
 179      * One more than the highest normal UDateAbsoluteUnit value.
 180      * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
 181      */
 182     UDAT_ABSOLUTE_UNIT_COUNT = UDAT_ABSOLUTE_NOW + 2
 183 #endif  // U_HIDE_DEPRECATED_API
 184 } UDateAbsoluteUnit;
 185
 186 /**
 187  * Represents a direction for an absolute unit e.g "Next Tuesday"
 188  * or "Last Tuesday"
 189  * @stable ICU 53
 190  */
 191 typedef enum UDateDirection {
 192
 193     /**
 194      * Two before. Not fully supported in every locale.
 195      * @stable ICU 53
 196      */
 197     UDAT_DIRECTION_LAST_2,
 198
 199     /**
 200      * Last
 201      * @stable ICU 53
 202      */
 203     UDAT_DIRECTION_LAST,
 204
 205     /**
 206      * This
 207      * @stable ICU 53
 208      */
 209     UDAT_DIRECTION_THIS,
 210
 211     /**
 212      * Next
 213      * @stable ICU 53
 214      */
 215     UDAT_DIRECTION_NEXT,
 216
 217     /**
 218      * Two after. Not fully supported in every locale.
 219      * @stable ICU 53
 220      */
 221     UDAT_DIRECTION_NEXT_2,
 222
 223     /**
 224      * Plain, which means the absence of a qualifier.
 225      * @stable ICU 53
 226      */
 227     UDAT_DIRECTION_PLAIN,
 228
 229 #ifndef U_HIDE_DEPRECATED_API
 230     /**
 231      * One more than the highest normal UDateDirection value.
 232      * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
 233      */
 234     UDAT_DIRECTION_COUNT
 235 #endif  // U_HIDE_DEPRECATED_API
 236 } UDateDirection;
 237
 238 #if !UCONFIG_NO_BREAK_ITERATION
 239
 240 #if U_SHOW_CPLUSPLUS_API
 241 U_NAMESPACE_BEGIN
 242
 243 class BreakIterator;
 244 class RelativeDateTimeCacheData;
 245 class SharedNumberFormat;
 246 class SharedPluralRules;
 247 class SharedBreakIterator;
 248 class NumberFormat;
 249 class UnicodeString;
 250 class FormattedRelativeDateTimeData;
 251
 252 #ifndef U_HIDE_DRAFT_API
 253 /**
 254  * An immutable class containing the result of a relative datetime formatting operation.
 255  *
 256  * Instances of this class are immutable and thread-safe.
 257  *
 258  * Not intended for public subclassing.
 259  *
 260  * @draft ICU 64
 261  */
 262 class U_I18N_API FormattedRelativeDateTime : public UMemory, public FormattedValue {
 263   public:
 264     /**
 265      * Default constructor; makes an empty FormattedRelativeDateTime.
 266      * @draft ICU 64
 267      */
 268     FormattedRelativeDateTime() : fData(nullptr), fErrorCode(U_INVALID_STATE_ERROR) {}
 269
 270     /**
 271      * Move constructor: Leaves the source FormattedRelativeDateTime in an undefined state.
 272      * @draft ICU 64
 273      */
 274     FormattedRelativeDateTime(FormattedRelativeDateTime&& src) U_NOEXCEPT;
 275
 276     /**
 277      * Destruct an instance of FormattedRelativeDateTime.
 278      * @draft ICU 64
 279      */
 280     virtual ~FormattedRelativeDateTime() U_OVERRIDE;
 281
 282     /** Copying not supported; use move constructor instead. */
 283     FormattedRelativeDateTime(const FormattedRelativeDateTime&) = delete;
 284
 285     /** Copying not supported; use move assignment instead. */
 286     FormattedRelativeDateTime& operator=(const FormattedRelativeDateTime&) = delete;
 287
 288     /**
 289      * Move assignment: Leaves the source FormattedRelativeDateTime in an undefined state.
 290      * @draft ICU 64
 291      */
 292     FormattedRelativeDateTime& operator=(FormattedRelativeDateTime&& src) U_NOEXCEPT;
 293
 294     /** @copydoc FormattedValue::toString() */
 295     UnicodeString toString(UErrorCode& status) const U_OVERRIDE;
 296
 297     /** @copydoc FormattedValue::toTempString() */
 298     UnicodeString toTempString(UErrorCode& status) const U_OVERRIDE;
 299
 300     /** @copydoc FormattedValue::appendTo() */
 301     Appendable &appendTo(Appendable& appendable, UErrorCode& status) const U_OVERRIDE;
 302
 303     /** @copydoc FormattedValue::nextPosition() */
 304     UBool nextPosition(ConstrainedFieldPosition& cfpos, UErrorCode& status) const U_OVERRIDE;
 305
 306   private:
 307     FormattedRelativeDateTimeData *fData;
 308     UErrorCode fErrorCode;
 309     explicit FormattedRelativeDateTime(FormattedRelativeDateTimeData *results)
 310         : fData(results), fErrorCode(U_ZERO_ERROR) {}
 311     explicit FormattedRelativeDateTime(UErrorCode errorCode)
 312         : fData(nullptr), fErrorCode(errorCode) {}
 313     friend class RelativeDateTimeFormatter;
 314 };
 315 #endif  /* U_HIDE_DRAFT_API */
 316
 317 /**
 318  * Formats simple relative dates. There are two types of relative dates that
 319  * it handles:
 320  * <ul>
 321  *   <li>relative dates with a quantity e.g "in 5 days"</li>
 322  *   <li>relative dates without a quantity e.g "next Tuesday"</li>
 323  * </ul>
 324  * <p>
 325  * This API is very basic and is intended to be a building block for more
 326  * fancy APIs. The caller tells it exactly what to display in a locale
 327  * independent way. While this class automatically provides the correct plural
 328  * forms, the grammatical form is otherwise as neutral as possible. It is the
 329  * caller's responsibility to handle cut-off logic such as deciding between
 330  * displaying "in 7 days" or "in 1 week." This API supports relative dates
 331  * involving one single unit. This API does not support relative dates
 332  * involving compound units,
 333  * e.g "in 5 days and 4 hours" nor does it support parsing.
 334  * <p>
 335  * This class is mostly thread safe and immutable with the following caveats:
 336  * 1. The assignment operator violates Immutability. It must not be used
 337  *    concurrently with other operations.
 338  * 2. Caller must not hold onto adopted pointers.
 339  * <p>
 340  * This class is not intended for public subclassing.
 341  * <p>
 342  * Here are some examples of use:
 343  * <blockquote>
 344  * <pre>
 345  * UErrorCode status = U_ZERO_ERROR;
 346  * UnicodeString appendTo;
 347  * RelativeDateTimeFormatter fmt(status);
 348  * // Appends "in 1 day"
 349  * fmt.format(
 350  *     1, UDAT_DIRECTION_NEXT, UDAT_RELATIVE_DAYS, appendTo, status);
 351  * // Appends "in 3 days"
 352  * fmt.format(
 353  *     3, UDAT_DIRECTION_NEXT, UDAT_RELATIVE_DAYS, appendTo, status);
 354  * // Appends "3.2 years ago"
 355  * fmt.format(
 356  *     3.2, UDAT_DIRECTION_LAST, UDAT_RELATIVE_YEARS, appendTo, status);
 357  * // Appends "last Sunday"
 358  * fmt.format(UDAT_DIRECTION_LAST, UDAT_ABSOLUTE_SUNDAY, appendTo, status);
 359  * // Appends "this Sunday"
 360  * fmt.format(UDAT_DIRECTION_THIS, UDAT_ABSOLUTE_SUNDAY, appendTo, status);
 361  * // Appends "next Sunday"
 362  * fmt.format(UDAT_DIRECTION_NEXT, UDAT_ABSOLUTE_SUNDAY, appendTo, status);
 363  * // Appends "Sunday"
 364  * fmt.format(UDAT_DIRECTION_PLAIN, UDAT_ABSOLUTE_SUNDAY, appendTo, status);
 365  *
 366  * // Appends "yesterday"
 367  * fmt.format(UDAT_DIRECTION_LAST, UDAT_ABSOLUTE_DAY, appendTo, status);
 368  * // Appends "today"
 369  * fmt.format(UDAT_DIRECTION_THIS, UDAT_ABSOLUTE_DAY, appendTo, status);
 370  * // Appends "tomorrow"
 371  * fmt.format(UDAT_DIRECTION_NEXT, UDAT_ABSOLUTE_DAY, appendTo, status);
 372  * // Appends "now"
 373  * fmt.format(UDAT_DIRECTION_PLAIN, UDAT_ABSOLUTE_NOW, appendTo, status);
 374  *
 375  * </pre>
 376  * </blockquote>
 377  * <p>
 378  * In the future, we may add more forms, such as abbreviated/short forms
 379  * (3 secs ago), and relative day periods ("yesterday afternoon"), etc.
 380  *
 381  * The RelativeDateTimeFormatter class is not intended for public subclassing.
 382  *
 383  * @stable ICU 53
 384  */
 385 class U_I18N_API RelativeDateTimeFormatter : public UObject {
 386 public:
 387
 388     /**
 389      * Create RelativeDateTimeFormatter with default locale.
 390      * @stable ICU 53
 391      */
 392     RelativeDateTimeFormatter(UErrorCode& status);
 393
 394     /**
 395      * Create RelativeDateTimeFormatter with given locale.
 396      * @stable ICU 53
 397      */
 398     RelativeDateTimeFormatter(const Locale& locale, UErrorCode& status);
 399
 400     /**
 401      * Create RelativeDateTimeFormatter with given locale and NumberFormat.
 402      *
 403      * @param locale the locale
 404      * @param nfToAdopt Constructed object takes ownership of this pointer.
 405      *   It is an error for caller to delete this pointer or change its
 406      *   contents after calling this constructor.
 407      * @param status Any error is returned here.
 408      * @stable ICU 53
 409      */
 410     RelativeDateTimeFormatter(
 411         const Locale& locale, NumberFormat *nfToAdopt, UErrorCode& status);
 412
 413     /**
 414      * Create RelativeDateTimeFormatter with given locale, NumberFormat,
 415      * and capitalization context.
 416      *
 417      * @param locale the locale
 418      * @param nfToAdopt Constructed object takes ownership of this pointer.
 419      *   It is an error for caller to delete this pointer or change its
 420      *   contents after calling this constructor. Caller may pass NULL for
 421      *   this argument if they want default number format behavior.
 422      * @param style the format style. The UDAT_RELATIVE bit field has no effect.
 423      * @param capitalizationContext A value from UDisplayContext that pertains to
 424      * capitalization.
 425      * @param status Any error is returned here.
 426      * @stable ICU 54
 427      */
 428     RelativeDateTimeFormatter(
 429             const Locale& locale,
 430             NumberFormat *nfToAdopt,
 431             UDateRelativeDateTimeFormatterStyle style,
 432             UDisplayContext capitalizationContext,
 433             UErrorCode& status);
 434
 435     /**
 436      * Copy constructor.
 437      * @stable ICU 53
 438      */
 439     RelativeDateTimeFormatter(const RelativeDateTimeFormatter& other);
 440
 441     /**
 442      * Assignment operator.
 443      * @stable ICU 53
 444      */
 445     RelativeDateTimeFormatter& operator=(
 446             const RelativeDateTimeFormatter& other);
 447
 448     /**
 449      * Destructor.
 450      * @stable ICU 53
 451      */
 452     virtual ~RelativeDateTimeFormatter();
 453
 454     /**
 455      * Formats a relative date with a quantity such as "in 5 days" or
 456      * "3 months ago"
 457      *
 458      * This method returns a String. To get more information about the
 459      * formatting result, use formatToValue().
 460      *
 461      * @param quantity The numerical amount e.g 5. This value is formatted
 462      * according to this object's NumberFormat object.
 463      * @param direction NEXT means a future relative date; LAST means a past
 464      * relative date. If direction is anything else, this method sets
 465      * status to U_ILLEGAL_ARGUMENT_ERROR.
 466      * @param unit the unit e.g day? month? year?
 467      * @param appendTo The string to which the formatted result will be
 468      *  appended
 469      * @param status ICU error code returned here.
 470      * @return appendTo
 471      * @stable ICU 53
 472      */
 473     UnicodeString& format(
 474             double quantity,
 475             UDateDirection direction,
 476             UDateRelativeUnit unit,
 477             UnicodeString& appendTo,
 478             UErrorCode& status) const;
 479
 480 #ifndef U_HIDE_DRAFT_API
 481     /**
 482      * Formats a relative date with a quantity such as "in 5 days" or
 483      * "3 months ago"
 484      *
 485      * This method returns a FormattedRelativeDateTime, which exposes more
 486      * information than the String returned by format().
 487      *
 488      * @param quantity The numerical amount e.g 5. This value is formatted
 489      * according to this object's NumberFormat object.
 490      * @param direction NEXT means a future relative date; LAST means a past
 491      * relative date. If direction is anything else, this method sets
 492      * status to U_ILLEGAL_ARGUMENT_ERROR.
 493      * @param unit the unit e.g day? month? year?
 494      * @param status ICU error code returned here.
 495      * @return The formatted relative datetime
 496      * @draft ICU 64
 497      */
 498     FormattedRelativeDateTime formatToValue(
 499             double quantity,
 500             UDateDirection direction,
 501             UDateRelativeUnit unit,
 502             UErrorCode& status) const;
 503 #endif  /* U_HIDE_DRAFT_API */
 504
 505     /**
 506      * Formats a relative date without a quantity.
 507      *
 508      * This method returns a String. To get more information about the
 509      * formatting result, use formatToValue().
 510      *
 511      * @param direction NEXT, LAST, THIS, etc.
 512      * @param unit e.g SATURDAY, DAY, MONTH
 513      * @param appendTo The string to which the formatted result will be
 514      *  appended. If the value of direction is documented as not being fully
 515      *  supported in all locales then this method leaves appendTo unchanged if
 516      *  no format string is available.
 517      * @param status ICU error code returned here.
 518      * @return appendTo
 519      * @stable ICU 53
 520      */
 521     UnicodeString& format(
 522             UDateDirection direction,
 523             UDateAbsoluteUnit unit,
 524             UnicodeString& appendTo,
 525             UErrorCode& status) const;
 526
 527 #ifndef U_HIDE_DRAFT_API
 528     /**
 529      * Formats a relative date without a quantity.
 530      *
 531      * This method returns a FormattedRelativeDateTime, which exposes more
 532      * information than the String returned by format().
 533      *
 534      * If the string is not available in the requested locale, the return
 535      * value will be empty (calling toString will give an empty string).
 536      *
 537      * @param direction NEXT, LAST, THIS, etc.
 538      * @param unit e.g SATURDAY, DAY, MONTH
 539      * @param status ICU error code returned here.
 540      * @return The formatted relative datetime
 541      * @draft ICU 64
 542      */
 543     FormattedRelativeDateTime formatToValue(
 544             UDateDirection direction,
 545             UDateAbsoluteUnit unit,
 546             UErrorCode& status) const;
 547 #endif  /* U_HIDE_DRAFT_API */
 548
 549     /**
 550      * Format a combination of URelativeDateTimeUnit and numeric offset
 551      * using a numeric style, e.g. "1 week ago", "in 1 week",
 552      * "5 weeks ago", "in 5 weeks".
 553      *
 554      * This method returns a String. To get more information about the
 555      * formatting result, use formatNumericToValue().
 556      *
 557      * @param offset    The signed offset for the specified unit. This
 558      *                  will be formatted according to this object's
 559      *                  NumberFormat object.
 560      * @param unit      The unit to use when formatting the relative
 561      *                  date, e.g. UDAT_REL_UNIT_WEEK,
 562      *                  UDAT_REL_UNIT_FRIDAY.
 563      * @param appendTo  The string to which the formatted result will be
 564      *                  appended.
 565      * @param status    ICU error code returned here.
 566      * @return          appendTo
 567      * @stable ICU 57
 568      */
 569     UnicodeString& formatNumeric(
 570             double offset,
 571             URelativeDateTimeUnit unit,
 572             UnicodeString& appendTo,
 573             UErrorCode& status) const;
 574
 575 #ifndef U_HIDE_DRAFT_API
 576     /**
 577      * Format a combination of URelativeDateTimeUnit and numeric offset
 578      * using a numeric style, e.g. "1 week ago", "in 1 week",
 579      * "5 weeks ago", "in 5 weeks".
 580      *
 581      * This method returns a FormattedRelativeDateTime, which exposes more
 582      * information than the String returned by formatNumeric().
 583      *
 584      * @param offset    The signed offset for the specified unit. This
 585      *                  will be formatted according to this object's
 586      *                  NumberFormat object.
 587      * @param unit      The unit to use when formatting the relative
 588      *                  date, e.g. UDAT_REL_UNIT_WEEK,
 589      *                  UDAT_REL_UNIT_FRIDAY.
 590      * @param status    ICU error code returned here.
 591      * @return          The formatted relative datetime
 592      * @draft ICU 64
 593      */
 594     FormattedRelativeDateTime formatNumericToValue(
 595             double offset,
 596             URelativeDateTimeUnit unit,
 597             UErrorCode& status) const;
 598 #endif  /* U_HIDE_DRAFT_API */
 599
 600     /**
 601      * Format a combination of URelativeDateTimeUnit and numeric offset
 602      * using a text style if possible, e.g. "last week", "this week",
 603      * "next week", "yesterday", "tomorrow". Falls back to numeric
 604      * style if no appropriate text term is available for the specified
 605      * offset in the object's locale.
 606      *
 607      * This method returns a String. To get more information about the
 608      * formatting result, use formatToValue().
 609      *
 610      * @param offset    The signed offset for the specified unit.
 611      * @param unit      The unit to use when formatting the relative
 612      *                  date, e.g. UDAT_REL_UNIT_WEEK,
 613      *                  UDAT_REL_UNIT_FRIDAY.
 614      * @param appendTo  The string to which the formatted result will be
 615      *                  appended.
 616      * @param status    ICU error code returned here.
 617      * @return          appendTo
 618      * @stable ICU 57
 619      */
 620     UnicodeString& format(
 621             double offset,
 622             URelativeDateTimeUnit unit,
 623             UnicodeString& appendTo,
 624             UErrorCode& status) const;
 625
 626 #ifndef U_HIDE_DRAFT_API
 627     /**
 628      * Format a combination of URelativeDateTimeUnit and numeric offset
 629      * using a text style if possible, e.g. "last week", "this week",
 630      * "next week", "yesterday", "tomorrow". Falls back to numeric
 631      * style if no appropriate text term is available for the specified
 632      * offset in the object's locale.
 633      *
 634      * This method returns a FormattedRelativeDateTime, which exposes more
 635      * information than the String returned by format().
 636      *
 637      * @param offset    The signed offset for the specified unit.
 638      * @param unit      The unit to use when formatting the relative
 639      *                  date, e.g. UDAT_REL_UNIT_WEEK,
 640      *                  UDAT_REL_UNIT_FRIDAY.
 641      * @param status    ICU error code returned here.
 642      * @return          The formatted relative datetime
 643      * @draft ICU 64
 644      */
 645     FormattedRelativeDateTime formatToValue(
 646             double offset,
 647             URelativeDateTimeUnit unit,
 648             UErrorCode& status) const;
 649 #endif  /* U_HIDE_DRAFT_API */
 650
 651     /**
 652      * Combines a relative date string and a time string in this object's
 653      * locale. This is done with the same date-time separator used for the
 654      * default calendar in this locale.
 655      *
 656      * @param relativeDateString the relative date, e.g 'yesterday'
 657      * @param timeString the time e.g '3:45'
 658      * @param appendTo concatenated date and time appended here
 659      * @param status ICU error code returned here.
 660      * @return appendTo
 661      * @stable ICU 53
 662      */
 663     UnicodeString& combineDateAndTime(
 664             const UnicodeString& relativeDateString,
 665             const UnicodeString& timeString,
 666             UnicodeString& appendTo,
 667             UErrorCode& status) const;
 668
 669     /**
 670      * Returns the NumberFormat this object is using.
 671      *
 672      * @stable ICU 53
 673      */
 674     const NumberFormat& getNumberFormat() const;
 675
 676     /**
 677      * Returns the capitalization context.
 678      *
 679      * @stable ICU 54
 680      */
 681     UDisplayContext getCapitalizationContext() const;
 682
 683     /**
 684      * Returns the format style.
 685      *
 686      * @stable ICU 54
 687      */
 688     UDateRelativeDateTimeFormatterStyle getFormatStyle() const;
 689
 690 private:
 691     const RelativeDateTimeCacheData* fCache;
 692     const SharedNumberFormat *fNumberFormat;
 693     const SharedPluralRules *fPluralRules;
 694     UDateRelativeDateTimeFormatterStyle fStyle;
 695     UDisplayContext fContext;
 696     const SharedBreakIterator *fOptBreakIterator;
 697     Locale fLocale;
 698     void init(
 699             NumberFormat *nfToAdopt,
 700             BreakIterator *brkIter,
 701             UErrorCode &status);
 702     UnicodeString& adjustForContext(UnicodeString &) const;
 703     UBool checkNoAdjustForContext(UErrorCode& status) const;
 704
 705     template<typename F, typename... Args>
 706     UnicodeString& doFormat(
 707             F callback,
 708             UnicodeString& appendTo,
 709             UErrorCode& status,
 710             Args... args) const;
 711
 712 #ifndef U_HIDE_DRAFT_API  // for FormattedRelativeDateTime
 713     template<typename F, typename... Args>
 714     FormattedRelativeDateTime doFormatToValue(
 715             F callback,
 716             UErrorCode& status,
 717             Args... args) const;
 718 #endif  // U_HIDE_DRAFT_API
 719
 720     void formatImpl(
 721             double quantity,
 722             UDateDirection direction,
 723             UDateRelativeUnit unit,
 724             FormattedRelativeDateTimeData& output,
 725             UErrorCode& status) const;
 726     void formatAbsoluteImpl(
 727             UDateDirection direction,
 728             UDateAbsoluteUnit unit,
 729             FormattedRelativeDateTimeData& output,
 730             UErrorCode& status) const;
 731     void formatNumericImpl(
 732             double offset,
 733             URelativeDateTimeUnit unit,
 734             FormattedRelativeDateTimeData& output,
 735             UErrorCode& status) const;
 736     void formatRelativeImpl(
 737             double offset,
 738             URelativeDateTimeUnit unit,
 739             FormattedRelativeDateTimeData& output,
 740             UErrorCode& status) const;
 741 };
 742
 743 U_NAMESPACE_END
 744 #endif // U_SHOW_CPLUSPLUS_API
 745
 746 #endif /* !UCONFIG_NO_BREAK_ITERATION */
 747 #endif /* !UCONFIG_NO_FORMATTING */
 748 #endif /* __RELDATEFMT_H */