icuSources/i18n/unicode/datefmt.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) 1997-2016, International Business Machines
   6  *   Corporation and others.  All Rights Reserved.
   7  ********************************************************************************
   8  *
   9  * File DATEFMT.H
  10  *
  11  * Modification History:
  12  *
  13  *   Date        Name        Description
  14  *   02/19/97    aliu        Converted from java.
  15  *   04/01/97    aliu        Added support for centuries.
  16  *   07/23/98    stephen     JDK 1.2 sync
  17  *   11/15/99    weiv        Added support for week of year/day of week formatting
  18  ********************************************************************************
  19  */
  20
  21 #ifndef DATEFMT_H
  22 #define DATEFMT_H
  23
  24 #include "unicode/utypes.h"
  25
  26 #if U_SHOW_CPLUSPLUS_API
  27
  28 #if !UCONFIG_NO_FORMATTING
  29
  30 #include "unicode/udat.h"
  31 #include "unicode/calendar.h"
  32 #include "unicode/numfmt.h"
  33 #include "unicode/format.h"
  34 #include "unicode/locid.h"
  35 #include "unicode/enumset.h"
  36 #include "unicode/udisplaycontext.h"
  37
  38 /**
  39  * \file
  40  * \brief C++ API: Abstract class for converting dates.
  41  */
  42
  43 U_NAMESPACE_BEGIN
  44
  45 class TimeZone;
  46 class DateTimePatternGenerator;
  47
  48 /**
  49  * \cond
  50  * Export an explicit template instantiation. (See digitlst.h, datefmt.h, and others.)
  51  * (When building DLLs for Windows this is required.)
  52  */
  53 #if U_PF_WINDOWS <= U_PLATFORM && U_PLATFORM <= U_PF_CYGWIN && !defined(U_IN_DOXYGEN)
  54 template class U_I18N_API EnumSet<UDateFormatBooleanAttribute,
  55             0,
  56             UDAT_BOOLEAN_ATTRIBUTE_COUNT>;
  57 #endif
  58 /** \endcond */
  59
  60 /**
  61  * DateFormat is an abstract class for a family of classes that convert dates and
  62  * times from their internal representations to textual form and back again in a
  63  * language-independent manner. Converting from the internal representation (milliseconds
  64  * since midnight, January 1, 1970) to text is known as "formatting," and converting
  65  * from text to millis is known as "parsing."  We currently define only one concrete
  66  * subclass of DateFormat: SimpleDateFormat, which can handle pretty much all normal
  67  * date formatting and parsing actions.
  68  * <P>
  69  * DateFormat helps you to format and parse dates for any locale. Your code can
  70  * be completely independent of the locale conventions for months, days of the
  71  * week, or even the calendar format: lunar vs. solar.
  72  * <P>
  73  * To format a date for the current Locale, use one of the static factory
  74  * methods:
  75  * <pre>
  76  * \code
  77  *      DateFormat* dfmt = DateFormat::createDateInstance();
  78  *      UDate myDate = Calendar::getNow();
  79  *      UnicodeString myString;
  80  *      myString = dfmt->format( myDate, myString );
  81  * \endcode
  82  * </pre>
  83  * If you are formatting multiple numbers, it is more efficient to get the
  84  * format and use it multiple times so that the system doesn't have to fetch the
  85  * information about the local language and country conventions multiple times.
  86  * <pre>
  87  * \code
  88  *      DateFormat* df = DateFormat::createDateInstance();
  89  *      UnicodeString myString;
  90  *      UDate myDateArr[] = { 0.0, 100000000.0, 2000000000.0 }; // test values
  91  *      for (int32_t i = 0; i < 3; ++i) {
  92  *          myString.remove();
  93  *          cout << df->format( myDateArr[i], myString ) << endl;
  94  *      }
  95  * \endcode
  96  * </pre>
  97  * To get specific fields of a date, you can use UFieldPosition to
  98  * get specific fields.
  99  * <pre>
 100  * \code
 101  *      DateFormat* dfmt = DateFormat::createDateInstance();
 102  *      FieldPosition pos(DateFormat::YEAR_FIELD);
 103  *      UnicodeString myString;
 104  *      myString = dfmt->format( myDate, myString );
 105  *      cout << myString << endl;
 106  *      cout << pos.getBeginIndex() << "," << pos. getEndIndex() << endl;
 107  * \endcode
 108  * </pre>
 109  * To format a date for a different Locale, specify it in the call to
 110  * createDateInstance().
 111  * <pre>
 112  * \code
 113  *       DateFormat* df =
 114  *           DateFormat::createDateInstance( DateFormat::SHORT, Locale::getFrance());
 115  * \endcode
 116  * </pre>
 117  * You can use a DateFormat to parse also.
 118  * <pre>
 119  * \code
 120  *       UErrorCode status = U_ZERO_ERROR;
 121  *       UDate myDate = df->parse(myString, status);
 122  * \endcode
 123  * </pre>
 124  * Use createDateInstance() to produce the normal date format for that country.
 125  * There are other static factory methods available. Use createTimeInstance()
 126  * to produce the normal time format for that country. Use createDateTimeInstance()
 127  * to produce a DateFormat that formats both date and time. You can pass in
 128  * different options to these factory methods to control the length of the
 129  * result; from SHORT to MEDIUM to LONG to FULL. The exact result depends on the
 130  * locale, but generally:
 131  * <ul type=round>
 132  *   <li>   SHORT is completely numeric, such as 12/13/52 or 3:30pm
 133  *   <li>   MEDIUM is longer, such as Jan 12, 1952
 134  *   <li>   LONG is longer, such as January 12, 1952 or 3:30:32pm
 135  *   <li>   FULL is pretty completely specified, such as
 136  *          Tuesday, April 12, 1952 AD or 3:30:42pm PST.
 137  * </ul>
 138  * You can also set the time zone on the format if you wish. If you want even
 139  * more control over the format or parsing, (or want to give your users more
 140  * control), you can try casting the DateFormat you get from the factory methods
 141  * to a SimpleDateFormat. This will work for the majority of countries; just
 142  * remember to chck getDynamicClassID() before carrying out the cast.
 143  * <P>
 144  * You can also use forms of the parse and format methods with ParsePosition and
 145  * FieldPosition to allow you to
 146  * <ul type=round>
 147  *   <li>   Progressively parse through pieces of a string.
 148  *   <li>   Align any particular field, or find out where it is for selection
 149  *          on the screen.
 150  * </ul>
 151  *
 152  * <p><em>User subclasses are not supported.</em> While clients may write
 153  * subclasses, such code will not necessarily work and will not be
 154  * guaranteed to work stably from release to release.
 155  */
 156 class U_I18N_API DateFormat : public Format {
 157 public:
 158
 159     /**
 160      * Constants for various style patterns. These reflect the order of items in
 161      * the DateTimePatterns resource. There are 4 time patterns, 4 date patterns,
 162      * the default date-time pattern, and 4 date-time patterns. Each block of 4 values
 163      * in the resource occurs in the order full, long, medium, short.
 164      * @stable ICU 2.4
 165      */
 166     enum EStyle
 167     {
 168         kNone   = -1,
 169
 170         kFull   = 0,
 171         kLong   = 1,
 172         kMedium = 2,
 173         kShort  = 3,
 174
 175         kDateOffset   = kShort + 1,
 176      // kFull   + kDateOffset = 4
 177      // kLong   + kDateOffset = 5
 178      // kMedium + kDateOffset = 6
 179      // kShort  + kDateOffset = 7
 180
 181         kDateTime             = 8,
 182      // Default DateTime
 183
 184         kDateTimeOffset = kDateTime + 1,
 185      // kFull   + kDateTimeOffset = 9
 186      // kLong   + kDateTimeOffset = 10
 187      // kMedium + kDateTimeOffset = 11
 188      // kShort  + kDateTimeOffset = 12
 189
 190         // relative dates
 191         kRelative = (1 << 7),
 192
 193         kFullRelative = (kFull | kRelative),
 194
 195         kLongRelative = kLong | kRelative,
 196
 197         kMediumRelative = kMedium | kRelative,
 198
 199         kShortRelative = kShort | kRelative,
 200
 201
 202         kDefault      = kMedium,
 203
 204
 205
 206     /**
 207      * These constants are provided for backwards compatibility only.
 208      * Please use the C++ style constants defined above.
 209      */
 210         FULL        = kFull,
 211         LONG        = kLong,
 212         MEDIUM        = kMedium,
 213         SHORT        = kShort,
 214         DEFAULT        = kDefault,
 215         DATE_OFFSET    = kDateOffset,
 216         NONE        = kNone,
 217         DATE_TIME    = kDateTime
 218     };
 219
 220     /**
 221      * Destructor.
 222      * @stable ICU 2.0
 223      */
 224     virtual ~DateFormat();
 225
 226     /**
 227      * Clones this object polymorphically.
 228      * The caller owns the result and should delete it when done.
 229      * @return clone, or nullptr if an error occurred
 230      * @stable ICU 2.0
 231      */
 232     virtual DateFormat* clone() const = 0;
 233
 234     /**
 235      * Equality operator.  Returns true if the two formats have the same behavior.
 236      * @stable ICU 2.0
 237      */
 238     virtual UBool operator==(const Format&) const;
 239
 240
 241     using Format::format;
 242
 243     /**
 244      * Format an object to produce a string. This method handles Formattable
 245      * objects with a UDate type. If a the Formattable object type is not a Date,
 246      * then it returns a failing UErrorCode.
 247      *
 248      * @param obj       The object to format. Must be a Date.
 249      * @param appendTo  Output parameter to receive result.
 250      *                  Result is appended to existing contents.
 251      * @param pos       On input: an alignment field, if desired.
 252      *                  On output: the offsets of the alignment field.
 253      * @param status    Output param filled with success/failure status.
 254      * @return          Reference to 'appendTo' parameter.
 255      * @stable ICU 2.0
 256      */
 257     virtual UnicodeString& format(const Formattable& obj,
 258                                   UnicodeString& appendTo,
 259                                   FieldPosition& pos,
 260                                   UErrorCode& status) const;
 261
 262     /**
 263      * Format an object to produce a string. This method handles Formattable
 264      * objects with a UDate type. If a the Formattable object type is not a Date,
 265      * then it returns a failing UErrorCode.
 266      *
 267      * @param obj       The object to format. Must be a Date.
 268      * @param appendTo  Output parameter to receive result.
 269      *                  Result is appended to existing contents.
 270      * @param posIter   On return, can be used to iterate over positions
 271      *                  of fields generated by this format call.  Field values
 272      *                  are defined in UDateFormatField.  Can be NULL.
 273      * @param status    Output param filled with success/failure status.
 274      * @return          Reference to 'appendTo' parameter.
 275      * @stable ICU 4.4
 276      */
 277     virtual UnicodeString& format(const Formattable& obj,
 278                                   UnicodeString& appendTo,
 279                                   FieldPositionIterator* posIter,
 280                                   UErrorCode& status) const;
 281     /**
 282      * Formats a date into a date/time string. This is an abstract method which
 283      * concrete subclasses must implement.
 284      * <P>
 285      * On input, the FieldPosition parameter may have its "field" member filled with
 286      * an enum value specifying a field.  On output, the FieldPosition will be filled
 287      * in with the text offsets for that field.
 288      * <P> For example, given a time text
 289      * "1996.07.10 AD at 15:08:56 PDT", if the given fieldPosition.field is
 290      * UDAT_YEAR_FIELD, the offsets fieldPosition.beginIndex and
 291      * statfieldPositionus.getEndIndex will be set to 0 and 4, respectively.
 292      * <P> Notice
 293      * that if the same time field appears more than once in a pattern, the status will
 294      * be set for the first occurence of that time field. For instance,
 295      * formatting a UDate to the time string "1 PM PDT (Pacific Daylight Time)"
 296      * using the pattern "h a z (zzzz)" and the alignment field
 297      * DateFormat::TIMEZONE_FIELD, the offsets fieldPosition.beginIndex and
 298      * fieldPosition.getEndIndex will be set to 5 and 8, respectively, for the first
 299      * occurence of the timezone pattern character 'z'.
 300      *
 301      * @param cal           Calendar set to the date and time to be formatted
 302      *                      into a date/time string.  When the calendar type is
 303      *                      different from the internal calendar held by this
 304      *                      DateFormat instance, the date and the time zone will
 305      *                      be inherited from the input calendar, but other calendar
 306      *                      field values will be calculated by the internal calendar.
 307      * @param appendTo      Output parameter to receive result.
 308      *                      Result is appended to existing contents.
 309      * @param fieldPosition On input: an alignment field, if desired (see examples above)
 310      *                      On output: the offsets of the alignment field (see examples above)
 311      * @return              Reference to 'appendTo' parameter.
 312      * @stable ICU 2.1
 313      */
 314     virtual UnicodeString& format(  Calendar& cal,
 315                                     UnicodeString& appendTo,
 316                                     FieldPosition& fieldPosition) const = 0;
 317
 318     /**
 319      * Formats a date into a date/time string. Subclasses should implement this method.
 320      *
 321      * @param cal       Calendar set to the date and time to be formatted
 322      *                  into a date/time string.  When the calendar type is
 323      *                  different from the internal calendar held by this
 324      *                  DateFormat instance, the date and the time zone will
 325      *                  be inherited from the input calendar, but other calendar
 326      *                  field values will be calculated by the internal calendar.
 327      * @param appendTo  Output parameter to receive result.
 328      *                  Result is appended to existing contents.
 329      * @param posIter   On return, can be used to iterate over positions
 330      *                  of fields generated by this format call.  Field values
 331      *                  are defined in UDateFormatField.  Can be NULL.
 332      * @param status    error status.
 333      * @return          Reference to 'appendTo' parameter.
 334      * @stable ICU 4.4
 335      */
 336     virtual UnicodeString& format(Calendar& cal,
 337                                   UnicodeString& appendTo,
 338                                   FieldPositionIterator* posIter,
 339                                   UErrorCode& status) const;
 340     /**
 341      * Formats a UDate into a date/time string.
 342      * <P>
 343      * On input, the FieldPosition parameter may have its "field" member filled with
 344      * an enum value specifying a field.  On output, the FieldPosition will be filled
 345      * in with the text offsets for that field.
 346      * <P> For example, given a time text
 347      * "1996.07.10 AD at 15:08:56 PDT", if the given fieldPosition.field is
 348      * UDAT_YEAR_FIELD, the offsets fieldPosition.beginIndex and
 349      * statfieldPositionus.getEndIndex will be set to 0 and 4, respectively.
 350      * <P> Notice
 351      * that if the same time field appears more than once in a pattern, the status will
 352      * be set for the first occurence of that time field. For instance,
 353      * formatting a UDate to the time string "1 PM PDT (Pacific Daylight Time)"
 354      * using the pattern "h a z (zzzz)" and the alignment field
 355      * DateFormat::TIMEZONE_FIELD, the offsets fieldPosition.beginIndex and
 356      * fieldPosition.getEndIndex will be set to 5 and 8, respectively, for the first
 357      * occurence of the timezone pattern character 'z'.
 358      *
 359      * @param date          UDate to be formatted into a date/time string.
 360      * @param appendTo      Output parameter to receive result.
 361      *                      Result is appended to existing contents.
 362      * @param fieldPosition On input: an alignment field, if desired (see examples above)
 363      *                      On output: the offsets of the alignment field (see examples above)
 364      * @return              Reference to 'appendTo' parameter.
 365      * @stable ICU 2.0
 366      */
 367     UnicodeString& format(  UDate date,
 368                             UnicodeString& appendTo,
 369                             FieldPosition& fieldPosition) const;
 370
 371     /**
 372      * Formats a UDate into a date/time string.
 373      *
 374      * @param date      UDate to be formatted into a date/time string.
 375      * @param appendTo  Output parameter to receive result.
 376      *                  Result is appended to existing contents.
 377      * @param posIter   On return, can be used to iterate over positions
 378      *                  of fields generated by this format call.  Field values
 379      *                  are defined in UDateFormatField.  Can be NULL.
 380      * @param status    error status.
 381      * @return          Reference to 'appendTo' parameter.
 382      * @stable ICU 4.4
 383      */
 384     UnicodeString& format(UDate date,
 385                           UnicodeString& appendTo,
 386                           FieldPositionIterator* posIter,
 387                           UErrorCode& status) const;
 388     /**
 389      * Formats a UDate into a date/time string. If there is a problem, you won't
 390      * know, using this method. Use the overloaded format() method which takes a
 391      * FieldPosition& to detect formatting problems.
 392      *
 393      * @param date      The UDate value to be formatted into a string.
 394      * @param appendTo  Output parameter to receive result.
 395      *                  Result is appended to existing contents.
 396      * @return          Reference to 'appendTo' parameter.
 397      * @stable ICU 2.0
 398      */
 399     UnicodeString& format(UDate date, UnicodeString& appendTo) const;
 400
 401     /**
 402      * Parse a date/time string. For example, a time text "07/10/96 4:5 PM, PDT"
 403      * will be parsed into a UDate that is equivalent to Date(837039928046).
 404      * Parsing begins at the beginning of the string and proceeds as far as
 405      * possible.  Assuming no parse errors were encountered, this function
 406      * doesn't return any information about how much of the string was consumed
 407      * by the parsing.  If you need that information, use the version of
 408      * parse() that takes a ParsePosition.
 409      * <P>
 410      * By default, parsing is lenient: If the input is not in the form used by
 411      * this object's format method but can still be parsed as a date, then the
 412      * parse succeeds. Clients may insist on strict adherence to the format by
 413      * calling setLenient(false).
 414      * @see DateFormat::setLenient(boolean)
 415      * <P>
 416      * Note that the normal date formats associated with some calendars - such
 417      * as the Chinese lunar calendar - do not specify enough fields to enable
 418      * dates to be parsed unambiguously. In the case of the Chinese lunar
 419      * calendar, while the year within the current 60-year cycle is specified,
 420      * the number of such cycles since the start date of the calendar (in the
 421      * ERA field of the Calendar object) is not normally part of the format,
 422      * and parsing may assume the wrong era. For cases such as this it is
 423      * recommended that clients parse using the method
 424      * parse(const UnicodeString&, Calendar& cal, ParsePosition&)
 425      * with the Calendar passed in set to the current date, or to a date
 426      * within the era/cycle that should be assumed if absent in the format.
 427      *
 428      * @param text      The date/time string to be parsed into a UDate value.
 429      * @param status    Output param to be set to success/failure code. If
 430      *                  'text' cannot be parsed, it will be set to a failure
 431      *                  code.
 432      * @return          The parsed UDate value, if successful.
 433      * @stable ICU 2.0
 434      */
 435     virtual UDate parse( const UnicodeString& text,
 436                         UErrorCode& status) const;
 437
 438     /**
 439      * Parse a date/time string beginning at the given parse position. For
 440      * example, a time text "07/10/96 4:5 PM, PDT" will be parsed into a Date
 441      * that is equivalent to Date(837039928046).
 442      * <P>
 443      * By default, parsing is lenient: If the input is not in the form used by
 444      * this object's format method but can still be parsed as a date, then the
 445      * parse succeeds. Clients may insist on strict adherence to the format by
 446      * calling setLenient(false).
 447      * @see DateFormat::setLenient(boolean)
 448      *
 449      * @param text  The date/time string to be parsed.
 450      * @param cal   A Calendar set on input to the date and time to be used for
 451      *              missing values in the date/time string being parsed, and set
 452      *              on output to the parsed date/time. When the calendar type is
 453      *              different from the internal calendar held by this DateFormat
 454      *              instance, the internal calendar will be cloned to a work
 455      *              calendar set to the same milliseconds and time zone as the
 456      *              cal parameter, field values will be parsed based on the work
 457      *              calendar, then the result (milliseconds and time zone) will
 458      *              be set in this calendar.
 459      * @param pos   On input, the position at which to start parsing; on
 460      *              output, the position at which parsing terminated, or the
 461      *              start position if the parse failed.
 462      * @stable ICU 2.1
 463      */
 464     virtual void parse( const UnicodeString& text,
 465                         Calendar& cal,
 466                         ParsePosition& pos) const = 0;
 467
 468     /**
 469      * Parse a date/time string beginning at the given parse position. For
 470      * example, a time text "07/10/96 4:5 PM, PDT" will be parsed into a Date
 471      * that is equivalent to Date(837039928046).
 472      * <P>
 473      * By default, parsing is lenient: If the input is not in the form used by
 474      * this object's format method but can still be parsed as a date, then the
 475      * parse succeeds. Clients may insist on strict adherence to the format by
 476      * calling setLenient(false).
 477      * @see DateFormat::setLenient(boolean)
 478      * <P>
 479      * Note that the normal date formats associated with some calendars - such
 480      * as the Chinese lunar calendar - do not specify enough fields to enable
 481      * dates to be parsed unambiguously. In the case of the Chinese lunar
 482      * calendar, while the year within the current 60-year cycle is specified,
 483      * the number of such cycles since the start date of the calendar (in the
 484      * ERA field of the Calendar object) is not normally part of the format,
 485      * and parsing may assume the wrong era. For cases such as this it is
 486      * recommended that clients parse using the method
 487      * parse(const UnicodeString&, Calendar& cal, ParsePosition&)
 488      * with the Calendar passed in set to the current date, or to a date
 489      * within the era/cycle that should be assumed if absent in the format.
 490      *
 491      * @param text  The date/time string to be parsed into a UDate value.
 492      * @param pos   On input, the position at which to start parsing; on
 493      *              output, the position at which parsing terminated, or the
 494      *              start position if the parse failed.
 495      * @return      A valid UDate if the input could be parsed.
 496      * @stable ICU 2.0
 497      */
 498     UDate parse( const UnicodeString& text,
 499                  ParsePosition& pos) const;
 500
 501     /**
 502      * Parse a string to produce an object. This methods handles parsing of
 503      * date/time strings into Formattable objects with UDate types.
 504      * <P>
 505      * Before calling, set parse_pos.index to the offset you want to start
 506      * parsing at in the source. After calling, parse_pos.index is the end of
 507      * the text you parsed. If error occurs, index is unchanged.
 508      * <P>
 509      * When parsing, leading whitespace is discarded (with a successful parse),
 510      * while trailing whitespace is left as is.
 511      * <P>
 512      * See Format::parseObject() for more.
 513      *
 514      * @param source    The string to be parsed into an object.
 515      * @param result    Formattable to be set to the parse result.
 516      *                  If parse fails, return contents are undefined.
 517      * @param parse_pos The position to start parsing at. Upon return
 518      *                  this param is set to the position after the
 519      *                  last character successfully parsed. If the
 520      *                  source is not parsed successfully, this param
 521      *                  will remain unchanged.
 522      * @stable ICU 2.0
 523      */
 524     virtual void parseObject(const UnicodeString& source,
 525                              Formattable& result,
 526                              ParsePosition& parse_pos) const;
 527
 528     /**
 529      * Create a default date/time formatter that uses the SHORT style for both
 530      * the date and the time.
 531      *
 532      * @return A date/time formatter which the caller owns.
 533      * @stable ICU 2.0
 534      */
 535     static DateFormat* U_EXPORT2 createInstance(void);
 536
 537     /**
 538      * Creates a time formatter with the given formatting style for the given
 539      * locale.
 540      *
 541      * @param style     The given formatting style. For example,
 542      *                  SHORT for "h:mm a" in the US locale. Relative
 543      *                  time styles are not currently supported.
 544      * @param aLocale   The given locale.
 545      * @return          A time formatter which the caller owns.
 546      * @stable ICU 2.0
 547      */
 548     static DateFormat* U_EXPORT2 createTimeInstance(EStyle style = kDefault,
 549                                           const Locale& aLocale = Locale::getDefault());
 550
 551     /**
 552      * Creates a date formatter with the given formatting style for the given
 553      * const locale.
 554      *
 555      * @param style     The given formatting style. For example, SHORT for "M/d/yy" in the
 556      *                  US locale. As currently implemented, relative date formatting only
 557      *                  affects a limited range of calendar days before or after the
 558      *                  current date, based on the CLDR &lt;field type="day"&gt;/&lt;relative&gt; data:
 559      *                  For example, in English, "Yesterday", "Today", and "Tomorrow".
 560      *                  Outside of this range, dates are formatted using the corresponding
 561      *                  non-relative style.
 562      * @param aLocale   The given locale.
 563      * @return          A date formatter which the caller owns.
 564      * @stable ICU 2.0
 565      */
 566     static DateFormat* U_EXPORT2 createDateInstance(EStyle style = kDefault,
 567                                           const Locale& aLocale = Locale::getDefault());
 568
 569     /**
 570      * Creates a date/time formatter with the given formatting styles for the
 571      * given locale.
 572      *
 573      * @param dateStyle The given formatting style for the date portion of the result.
 574      *                  For example, SHORT for "M/d/yy" in the US locale. As currently
 575      *                  implemented, relative date formatting only affects a limited range
 576      *                  of calendar days before or after the current date, based on the
 577      *                  CLDR &lt;field type="day"&gt;/&lt;relative&gt; data: For example, in English,
 578      *                  "Yesterday", "Today", and "Tomorrow". Outside of this range, dates
 579      *                  are formatted using the corresponding non-relative style.
 580      * @param timeStyle The given formatting style for the time portion of the result.
 581      *                  For example, SHORT for "h:mm a" in the US locale. Relative
 582      *                  time styles are not currently supported.
 583      * @param aLocale   The given locale.
 584      * @return          A date/time formatter which the caller owns.
 585      * @stable ICU 2.0
 586      */
 587     static DateFormat* U_EXPORT2 createDateTimeInstance(EStyle dateStyle = kDefault,
 588                                               EStyle timeStyle = kDefault,
 589                                               const Locale& aLocale = Locale::getDefault());
 590
 591 #ifndef U_HIDE_INTERNAL_API
 592     /**
 593      * Returns the best pattern given a skeleton and locale.
 594      * @param locale the locale
 595      * @param skeleton the skeleton
 596      * @param status ICU error returned here
 597      * @return the best pattern.
 598      * @internal For ICU use only.
 599      */
 600     static UnicodeString getBestPattern(
 601             const Locale &locale,
 602             const UnicodeString &skeleton,
 603             UErrorCode &status);
 604 #endif  /* U_HIDE_INTERNAL_API */
 605
 606     /**
 607      * Creates a date/time formatter for the given skeleton and
 608      * default locale.
 609      *
 610      * @param skeleton The skeleton e.g "yMMMMd." Fields in the skeleton can
 611      *                 be in any order, and this method uses the locale to
 612      *                 map the skeleton to a pattern that includes locale
 613      *                 specific separators with the fields in the appropriate
 614      *                 order for that locale.
 615      * @param status   Any error returned here.
 616      * @return         A date/time formatter which the caller owns.
 617      * @stable ICU 55
 618      */
 619     static DateFormat* U_EXPORT2 createInstanceForSkeleton(
 620             const UnicodeString& skeleton,
 621             UErrorCode &status);
 622
 623     /**
 624      * Creates a date/time formatter for the given skeleton and locale.
 625      *
 626      * @param skeleton The skeleton e.g "yMMMMd." Fields in the skeleton can
 627      *                 be in any order, and this method uses the locale to
 628      *                 map the skeleton to a pattern that includes locale
 629      *                 specific separators with the fields in the appropriate
 630      *                 order for that locale.
 631      * @param locale  The given locale.
 632      * @param status   Any error returned here.
 633      * @return         A date/time formatter which the caller owns.
 634      * @stable ICU 55
 635      */
 636     static DateFormat* U_EXPORT2 createInstanceForSkeleton(
 637             const UnicodeString& skeleton,
 638             const Locale &locale,
 639             UErrorCode &status);
 640
 641     /**
 642      * Creates a date/time formatter for the given skeleton and locale.
 643      *
 644      * @param calendarToAdopt the calendar returned DateFormat is to use.
 645      * @param skeleton The skeleton e.g "yMMMMd." Fields in the skeleton can
 646      *                 be in any order, and this method uses the locale to
 647      *                 map the skeleton to a pattern that includes locale
 648      *                 specific separators with the fields in the appropriate
 649      *                 order for that locale.
 650      * @param locale  The given locale.
 651      * @param status   Any error returned here.
 652      * @return         A date/time formatter which the caller owns.
 653      * @stable ICU 55
 654      */
 655     static DateFormat* U_EXPORT2 createInstanceForSkeleton(
 656             Calendar *calendarToAdopt,
 657             const UnicodeString& skeleton,
 658             const Locale &locale,
 659             UErrorCode &status);
 660
 661
 662     /**
 663      * Gets the set of locales for which DateFormats are installed.
 664      * @param count Filled in with the number of locales in the list that is returned.
 665      * @return the set of locales for which DateFormats are installed.  The caller
 666      *  does NOT own this list and must not delete it.
 667      * @stable ICU 2.0
 668      */
 669     static const Locale* U_EXPORT2 getAvailableLocales(int32_t& count);
 670
 671     /**
 672      * Returns whether both date/time parsing in the encapsulated Calendar object and DateFormat whitespace &
 673      * numeric processing is lenient.
 674      * @stable ICU 2.0
 675      */
 676     virtual UBool isLenient(void) const;
 677
 678     /**
 679      * Specifies whether date/time parsing is to be lenient.  With
 680      * lenient parsing, the parser may use heuristics to interpret inputs that
 681      * do not precisely match this object's format.  Without lenient parsing,
 682      * inputs must match this object's format more closely.
 683      *
 684      * Note: ICU 53 introduced finer grained control of leniency (and added
 685      * new control points) making the preferred method a combination of
 686      * setCalendarLenient() & setBooleanAttribute() calls.
 687      * This method supports prior functionality but may not support all
 688      * future leniency control & behavior of DateFormat. For control of pre 53 leniency,
 689      * Calendar and DateFormat whitespace & numeric tolerance, this method is safe to
 690      * use. However, mixing leniency control via this method and modification of the
 691      * newer attributes via setBooleanAttribute() may produce undesirable
 692      * results.
 693      *
 694      * @param lenient  True specifies date/time interpretation to be lenient.
 695      * @see Calendar::setLenient
 696      * @stable ICU 2.0
 697      */
 698     virtual void setLenient(UBool lenient);
 699
 700
 701     /**
 702      * Returns whether date/time parsing in the encapsulated Calendar object processing is lenient.
 703      * @stable ICU 53
 704      */
 705     virtual UBool isCalendarLenient(void) const;
 706
 707
 708     /**
 709      * Specifies whether encapsulated Calendar date/time parsing is to be lenient.  With
 710      * lenient parsing, the parser may use heuristics to interpret inputs that
 711      * do not precisely match this object's format.  Without lenient parsing,
 712      * inputs must match this object's format more closely.
 713      * @param lenient when true, parsing is lenient
 714      * @see com.ibm.icu.util.Calendar#setLenient
 715      * @stable ICU 53
 716      */
 717     virtual void setCalendarLenient(UBool lenient);
 718
 719
 720     /**
 721      * Gets the calendar associated with this date/time formatter.
 722      * The calendar is owned by the formatter and must not be modified.
 723      * Also, the calendar does not reflect the results of a parse operation.
 724      * To parse to a calendar, use {@link #parse(const UnicodeString&, Calendar& cal, ParsePosition&) const parse(const UnicodeString&, Calendar& cal, ParsePosition&)}
 725      * @return the calendar associated with this date/time formatter.
 726      * @stable ICU 2.0
 727      */
 728     virtual const Calendar* getCalendar(void) const;
 729
 730     /**
 731      * Set the calendar to be used by this date format. Initially, the default
 732      * calendar for the specified or default locale is used.  The caller should
 733      * not delete the Calendar object after it is adopted by this call.
 734      * Adopting a new calendar will change to the default symbols.
 735      *
 736      * @param calendarToAdopt    Calendar object to be adopted.
 737      * @stable ICU 2.0
 738      */
 739     virtual void adoptCalendar(Calendar* calendarToAdopt);
 740
 741     /**
 742      * Set the calendar to be used by this date format. Initially, the default
 743      * calendar for the specified or default locale is used.
 744      *
 745      * @param newCalendar Calendar object to be set.
 746      * @stable ICU 2.0
 747      */
 748     virtual void setCalendar(const Calendar& newCalendar);
 749
 750
 751     /**
 752      * Gets the number formatter which this date/time formatter uses to format
 753      * and parse the numeric portions of the pattern.
 754      * @return the number formatter which this date/time formatter uses.
 755      * @stable ICU 2.0
 756      */
 757     virtual const NumberFormat* getNumberFormat(void) const;
 758
 759     /**
 760      * Allows you to set the number formatter.  The caller should
 761      * not delete the NumberFormat object after it is adopted by this call.
 762      * @param formatToAdopt     NumberFormat object to be adopted.
 763      * @stable ICU 2.0
 764      */
 765     virtual void adoptNumberFormat(NumberFormat* formatToAdopt);
 766
 767     /**
 768      * Allows you to set the number formatter.
 769      * @param newNumberFormat  NumberFormat object to be set.
 770      * @stable ICU 2.0
 771      */
 772     virtual void setNumberFormat(const NumberFormat& newNumberFormat);
 773
 774     /**
 775      * Returns a reference to the TimeZone used by this DateFormat's calendar.
 776      * @return the time zone associated with the calendar of DateFormat.
 777      * @stable ICU 2.0
 778      */
 779     virtual const TimeZone& getTimeZone(void) const;
 780
 781     /**
 782      * Sets the time zone for the calendar of this DateFormat object. The caller
 783      * no longer owns the TimeZone object and should not delete it after this call.
 784      * @param zoneToAdopt the TimeZone to be adopted.
 785      * @stable ICU 2.0
 786      */
 787     virtual void adoptTimeZone(TimeZone* zoneToAdopt);
 788
 789     /**
 790      * Sets the time zone for the calendar of this DateFormat object.
 791      * @param zone the new time zone.
 792      * @stable ICU 2.0
 793      */
 794     virtual void setTimeZone(const TimeZone& zone);
 795
 796     /**
 797      * Set a particular UDisplayContext value in the formatter, such as
 798      * UDISPCTX_CAPITALIZATION_FOR_STANDALONE.
 799      * @param value The UDisplayContext value to set.
 800      * @param status Input/output status. If at entry this indicates a failure
 801      *               status, the function will do nothing; otherwise this will be
 802      *               updated with any new status from the function.
 803      * @stable ICU 53
 804      */
 805     virtual void setContext(UDisplayContext value, UErrorCode& status);
 806
 807     /**
 808      * Get the formatter's UDisplayContext value for the specified UDisplayContextType,
 809      * such as UDISPCTX_TYPE_CAPITALIZATION.
 810      * @param type The UDisplayContextType whose value to return
 811      * @param status Input/output status. If at entry this indicates a failure
 812      *               status, the function will do nothing; otherwise this will be
 813      *               updated with any new status from the function.
 814      * @return The UDisplayContextValue for the specified type.
 815      * @stable ICU 53
 816      */
 817     virtual UDisplayContext getContext(UDisplayContextType type, UErrorCode& status) const;
 818
 819    /**
 820      * Sets an boolean attribute on this DateFormat.
 821      * May return U_UNSUPPORTED_ERROR if this instance does not support
 822      * the specified attribute.
 823      * @param attr the attribute to set
 824      * @param newvalue new value
 825      * @param status the error type
 826      * @return *this - for chaining (example: format.setAttribute(...).setAttribute(...) )
 827      * @stable ICU 53
 828      */
 829
 830     virtual DateFormat&  U_EXPORT2 setBooleanAttribute(UDateFormatBooleanAttribute attr,
 831                                                                         UBool newvalue,
 832                                                                         UErrorCode &status);
 833
 834     /**
 835      * Returns a boolean from this DateFormat
 836      * May return U_UNSUPPORTED_ERROR if this instance does not support
 837      * the specified attribute.
 838      * @param attr the attribute to set
 839      * @param status the error type
 840      * @return the attribute value. Undefined if there is an error.
 841      * @stable ICU 53
 842      */
 843     virtual UBool U_EXPORT2 getBooleanAttribute(UDateFormatBooleanAttribute attr, UErrorCode &status) const;
 844
 845 protected:
 846     /**
 847      * Default constructor.  Creates a DateFormat with no Calendar or NumberFormat
 848      * associated with it.  This constructor depends on the subclasses to fill in
 849      * the calendar and numberFormat fields.
 850      * @stable ICU 2.0
 851      */
 852     DateFormat();
 853
 854     /**
 855      * Copy constructor.
 856      * @stable ICU 2.0
 857      */
 858     DateFormat(const DateFormat&);
 859
 860     /**
 861      * Default assignment operator.
 862      * @stable ICU 2.0
 863      */
 864     DateFormat& operator=(const DateFormat&);
 865
 866     /**
 867      * The calendar that DateFormat uses to produce the time field values needed
 868      * to implement date/time formatting. Subclasses should generally initialize
 869      * this to the default calendar for the locale associated with this DateFormat.
 870      * @stable ICU 2.4
 871      */
 872     Calendar* fCalendar;
 873
 874     /**
 875      * The number formatter that DateFormat uses to format numbers in dates and
 876      * times. Subclasses should generally initialize this to the default number
 877      * format for the locale associated with this DateFormat.
 878      * @stable ICU 2.4
 879      */
 880     NumberFormat* fNumberFormat;
 881
 882
 883 private:
 884
 885     /**
 886      * Gets the date/time formatter with the given formatting styles for the
 887      * given locale.
 888      * @param dateStyle the given date formatting style.
 889      * @param timeStyle the given time formatting style.
 890      * @param inLocale the given locale.
 891      * @return a date/time formatter, or 0 on failure.
 892      */
 893     static DateFormat* U_EXPORT2 create(EStyle timeStyle, EStyle dateStyle, const Locale& inLocale);
 894
 895
 896     /**
 897      * enum set of active boolean attributes for this instance
 898      */
 899     EnumSet<UDateFormatBooleanAttribute, 0, UDAT_BOOLEAN_ATTRIBUTE_COUNT> fBoolFlags;
 900
 901
 902     UDisplayContext fCapitalizationContext;
 903     friend class DateFmtKeyByStyle;
 904
 905 public:
 906 #ifndef U_HIDE_OBSOLETE_API
 907     /**
 908      * Field selector for FieldPosition for DateFormat fields.
 909      * @obsolete ICU 3.4 use UDateFormatField instead, since this API will be
 910      * removed in that release
 911      */
 912     enum EField
 913     {
 914         // Obsolete; use UDateFormatField instead
 915         kEraField = UDAT_ERA_FIELD,
 916         kYearField = UDAT_YEAR_FIELD,
 917         kMonthField = UDAT_MONTH_FIELD,
 918         kDateField = UDAT_DATE_FIELD,
 919         kHourOfDay1Field = UDAT_HOUR_OF_DAY1_FIELD,
 920         kHourOfDay0Field = UDAT_HOUR_OF_DAY0_FIELD,
 921         kMinuteField = UDAT_MINUTE_FIELD,
 922         kSecondField = UDAT_SECOND_FIELD,
 923         kMillisecondField = UDAT_FRACTIONAL_SECOND_FIELD,
 924         kDayOfWeekField = UDAT_DAY_OF_WEEK_FIELD,
 925         kDayOfYearField = UDAT_DAY_OF_YEAR_FIELD,
 926         kDayOfWeekInMonthField = UDAT_DAY_OF_WEEK_IN_MONTH_FIELD,
 927         kWeekOfYearField = UDAT_WEEK_OF_YEAR_FIELD,
 928         kWeekOfMonthField = UDAT_WEEK_OF_MONTH_FIELD,
 929         kAmPmField = UDAT_AM_PM_FIELD,
 930         kHour1Field = UDAT_HOUR1_FIELD,
 931         kHour0Field = UDAT_HOUR0_FIELD,
 932         kTimezoneField = UDAT_TIMEZONE_FIELD,
 933         kYearWOYField = UDAT_YEAR_WOY_FIELD,
 934         kDOWLocalField = UDAT_DOW_LOCAL_FIELD,
 935         kExtendedYearField = UDAT_EXTENDED_YEAR_FIELD,
 936         kJulianDayField = UDAT_JULIAN_DAY_FIELD,
 937         kMillisecondsInDayField = UDAT_MILLISECONDS_IN_DAY_FIELD,
 938
 939         // Obsolete; use UDateFormatField instead
 940         ERA_FIELD = UDAT_ERA_FIELD,
 941         YEAR_FIELD = UDAT_YEAR_FIELD,
 942         MONTH_FIELD = UDAT_MONTH_FIELD,
 943         DATE_FIELD = UDAT_DATE_FIELD,
 944         HOUR_OF_DAY1_FIELD = UDAT_HOUR_OF_DAY1_FIELD,
 945         HOUR_OF_DAY0_FIELD = UDAT_HOUR_OF_DAY0_FIELD,
 946         MINUTE_FIELD = UDAT_MINUTE_FIELD,
 947         SECOND_FIELD = UDAT_SECOND_FIELD,
 948         MILLISECOND_FIELD = UDAT_FRACTIONAL_SECOND_FIELD,
 949         DAY_OF_WEEK_FIELD = UDAT_DAY_OF_WEEK_FIELD,
 950         DAY_OF_YEAR_FIELD = UDAT_DAY_OF_YEAR_FIELD,
 951         DAY_OF_WEEK_IN_MONTH_FIELD = UDAT_DAY_OF_WEEK_IN_MONTH_FIELD,
 952         WEEK_OF_YEAR_FIELD = UDAT_WEEK_OF_YEAR_FIELD,
 953         WEEK_OF_MONTH_FIELD = UDAT_WEEK_OF_MONTH_FIELD,
 954         AM_PM_FIELD = UDAT_AM_PM_FIELD,
 955         HOUR1_FIELD = UDAT_HOUR1_FIELD,
 956         HOUR0_FIELD = UDAT_HOUR0_FIELD,
 957         TIMEZONE_FIELD = UDAT_TIMEZONE_FIELD
 958     };
 959 #endif  /* U_HIDE_OBSOLETE_API */
 960 };
 961
 962 U_NAMESPACE_END
 963
 964 #endif /* #if !UCONFIG_NO_FORMATTING */
 965
 966 #endif /* U_SHOW_CPLUSPLUS_API */
 967
 968 #endif // _DATEFMT
 969 //eof