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      1 /*
      2  ********************************************************************************
      3  *   Copyright (C) 1997-2013, International Business Machines
      4  *   Corporation and others.  All Rights Reserved.
      5  ********************************************************************************
      6  *
      7  * File DATEFMT.H
      8  *
      9  * Modification History:
     10  *
     11  *   Date        Name        Description
     12  *   02/19/97    aliu        Converted from java.
     13  *   04/01/97    aliu        Added support for centuries.
     14  *   07/23/98    stephen     JDK 1.2 sync
     15  *   11/15/99    weiv        Added support for week of year/day of week formatting
     16  ********************************************************************************
     17  */
     18 
     19 #ifndef DATEFMT_H
     20 #define DATEFMT_H
     21 
     22 #include "unicode/utypes.h"
     23 
     24 #if !UCONFIG_NO_FORMATTING
     25 
     26 #include "unicode/udat.h"
     27 #include "unicode/calendar.h"
     28 #include "unicode/numfmt.h"
     29 #include "unicode/format.h"
     30 #include "unicode/locid.h"
     31 #include "unicode/enumset.h"
     32 
     33 /**
     34  * \file
     35  * \brief C++ API: Abstract class for converting dates.
     36  */
     37 
     38 U_NAMESPACE_BEGIN
     39 
     40 class TimeZone;
     41 class DateTimePatternGenerator;
     42 
     43 // explicit template instantiation. see digitlst.h
     44 #if defined (_MSC_VER)
     45 template class U_I18N_API EnumSet<UDateFormatBooleanAttribute,
     46             0,
     47             UDAT_BOOLEAN_ATTRIBUTE_COUNT>;
     48 #endif
     49 
     50 /**
     51  * DateFormat is an abstract class for a family of classes that convert dates and
     52  * times from their internal representations to textual form and back again in a
     53  * language-independent manner. Converting from the internal representation (milliseconds
     54  * since midnight, January 1, 1970) to text is known as "formatting," and converting
     55  * from text to millis is known as "parsing."  We currently define only one concrete
     56  * subclass of DateFormat: SimpleDateFormat, which can handle pretty much all normal
     57  * date formatting and parsing actions.
     58  * <P>
     59  * DateFormat helps you to format and parse dates for any locale. Your code can
     60  * be completely independent of the locale conventions for months, days of the
     61  * week, or even the calendar format: lunar vs. solar.
     62  * <P>
     63  * To format a date for the current Locale, use one of the static factory
     64  * methods:
     65  * <pre>
     66  * \code
     67  *      DateFormat* dfmt = DateFormat::createDateInstance();
     68  *      UDate myDate = Calendar::getNow();
     69  *      UnicodeString myString;
     70  *      myString = dfmt->format( myDate, myString );
     71  * \endcode
     72  * </pre>
     73  * If you are formatting multiple numbers, it is more efficient to get the
     74  * format and use it multiple times so that the system doesn't have to fetch the
     75  * information about the local language and country conventions multiple times.
     76  * <pre>
     77  * \code
     78  *      DateFormat* df = DateFormat::createDateInstance();
     79  *      UnicodeString myString;
     80  *      UDate myDateArr[] = { 0.0, 100000000.0, 2000000000.0 }; // test values
     81  *      for (int32_t i = 0; i < 3; ++i) {
     82  *          myString.remove();
     83  *          cout << df->format( myDateArr[i], myString ) << endl;
     84  *      }
     85  * \endcode
     86  * </pre>
     87  * To get specific fields of a date, you can use UFieldPosition to
     88  * get specific fields.
     89  * <pre>
     90  * \code
     91  *      DateFormat* dfmt = DateFormat::createDateInstance();
     92  *      FieldPosition pos(DateFormat::YEAR_FIELD);
     93  *      UnicodeString myString;
     94  *      myString = dfmt->format( myDate, myString );
     95  *      cout << myString << endl;
     96  *      cout << pos.getBeginIndex() << "," << pos. getEndIndex() << endl;
     97  * \endcode
     98  * </pre>
     99  * To format a date for a different Locale, specify it in the call to
    100  * createDateInstance().
    101  * <pre>
    102  * \code
    103  *       DateFormat* df =
    104  *           DateFormat::createDateInstance( DateFormat::SHORT, Locale::getFrance());
    105  * \endcode
    106  * </pre>
    107  * You can use a DateFormat to parse also.
    108  * <pre>
    109  * \code
    110  *       UErrorCode status = U_ZERO_ERROR;
    111  *       UDate myDate = df->parse(myString, status);
    112  * \endcode
    113  * </pre>
    114  * Use createDateInstance() to produce the normal date format for that country.
    115  * There are other static factory methods available. Use createTimeInstance()
    116  * to produce the normal time format for that country. Use createDateTimeInstance()
    117  * to produce a DateFormat that formats both date and time. You can pass in
    118  * different options to these factory methods to control the length of the
    119  * result; from SHORT to MEDIUM to LONG to FULL. The exact result depends on the
    120  * locale, but generally:
    121  * <ul type=round>
    122  *   <li>   SHORT is completely numeric, such as 12/13/52 or 3:30pm
    123  *   <li>   MEDIUM is longer, such as Jan 12, 1952
    124  *   <li>   LONG is longer, such as January 12, 1952 or 3:30:32pm
    125  *   <li>   FULL is pretty completely specified, such as
    126  *          Tuesday, April 12, 1952 AD or 3:30:42pm PST.
    127  * </ul>
    128  * You can also set the time zone on the format if you wish. If you want even
    129  * more control over the format or parsing, (or want to give your users more
    130  * control), you can try casting the DateFormat you get from the factory methods
    131  * to a SimpleDateFormat. This will work for the majority of countries; just
    132  * remember to chck getDynamicClassID() before carrying out the cast.
    133  * <P>
    134  * You can also use forms of the parse and format methods with ParsePosition and
    135  * FieldPosition to allow you to
    136  * <ul type=round>
    137  *   <li>   Progressively parse through pieces of a string.
    138  *   <li>   Align any particular field, or find out where it is for selection
    139  *          on the screen.
    140  * </ul>
    141  *
    142  * <p><em>User subclasses are not supported.</em> While clients may write
    143  * subclasses, such code will not necessarily work and will not be
    144  * guaranteed to work stably from release to release.
    145  */
    146 class U_I18N_API DateFormat : public Format {
    147 public:
    148 
    149     /**
    150      * Constants for various style patterns. These reflect the order of items in
    151      * the DateTimePatterns resource. There are 4 time patterns, 4 date patterns,
    152      * the default date-time pattern, and 4 date-time patterns. Each block of 4 values
    153      * in the resource occurs in the order full, long, medium, short.
    154      * @stable ICU 2.4
    155      */
    156     enum EStyle
    157     {
    158         kNone   = -1,
    159 
    160         kFull   = 0,
    161         kLong   = 1,
    162         kMedium = 2,
    163         kShort  = 3,
    164 
    165         kDateOffset   = kShort + 1,
    166      // kFull   + kDateOffset = 4
    167      // kLong   + kDateOffset = 5
    168      // kMedium + kDateOffset = 6
    169      // kShort  + kDateOffset = 7
    170 
    171         kDateTime             = 8,
    172      // Default DateTime
    173 
    174         kDateTimeOffset = kDateTime + 1,
    175      // kFull   + kDateTimeOffset = 9
    176      // kLong   + kDateTimeOffset = 10
    177      // kMedium + kDateTimeOffset = 11
    178      // kShort  + kDateTimeOffset = 12
    179 
    180         // relative dates
    181         kRelative = (1 << 7),
    182 
    183         kFullRelative = (kFull | kRelative),
    184 
    185         kLongRelative = kLong | kRelative,
    186 
    187         kMediumRelative = kMedium | kRelative,
    188 
    189         kShortRelative = kShort | kRelative,
    190 
    191 
    192         kDefault      = kMedium,
    193 
    194 
    195 
    196     /**
    197      * These constants are provided for backwards compatibility only.
    198      * Please use the C++ style constants defined above.
    199      */
    200         FULL        = kFull,
    201         LONG        = kLong,
    202         MEDIUM        = kMedium,
    203         SHORT        = kShort,
    204         DEFAULT        = kDefault,
    205         DATE_OFFSET    = kDateOffset,
    206         NONE        = kNone,
    207         DATE_TIME    = kDateTime
    208     };
    209 
    210     /**
    211      * Destructor.
    212      * @stable ICU 2.0
    213      */
    214     virtual ~DateFormat();
    215 
    216     /**
    217      * Equality operator.  Returns true if the two formats have the same behavior.
    218      * @stable ICU 2.0
    219      */
    220     virtual UBool operator==(const Format&) const;
    221 
    222 
    223     using Format::format;
    224 
    225     /**
    226      * Format an object to produce a string. This method handles Formattable
    227      * objects with a UDate type. If a the Formattable object type is not a Date,
    228      * then it returns a failing UErrorCode.
    229      *
    230      * @param obj       The object to format. Must be a Date.
    231      * @param appendTo  Output parameter to receive result.
    232      *                  Result is appended to existing contents.
    233      * @param pos       On input: an alignment field, if desired.
    234      *                  On output: the offsets of the alignment field.
    235      * @param status    Output param filled with success/failure status.
    236      * @return          Reference to 'appendTo' parameter.
    237      * @stable ICU 2.0
    238      */
    239     virtual UnicodeString& format(const Formattable& obj,
    240                                   UnicodeString& appendTo,
    241                                   FieldPosition& pos,
    242                                   UErrorCode& status) const;
    243 
    244     /**
    245      * Format an object to produce a string. This method handles Formattable
    246      * objects with a UDate type. If a the Formattable object type is not a Date,
    247      * then it returns a failing UErrorCode.
    248      *
    249      * @param obj       The object to format. Must be a Date.
    250      * @param appendTo  Output parameter to receive result.
    251      *                  Result is appended to existing contents.
    252      * @param posIter   On return, can be used to iterate over positions
    253      *                  of fields generated by this format call.  Field values
    254      *                  are defined in UDateFormatField.  Can be NULL.
    255      * @param status    Output param filled with success/failure status.
    256      * @return          Reference to 'appendTo' parameter.
    257      * @stable ICU 4.4
    258      */
    259     virtual UnicodeString& format(const Formattable& obj,
    260                                   UnicodeString& appendTo,
    261                                   FieldPositionIterator* posIter,
    262                                   UErrorCode& status) const;
    263     /**
    264      * Formats a date into a date/time string. This is an abstract method which
    265      * concrete subclasses must implement.
    266      * <P>
    267      * On input, the FieldPosition parameter may have its "field" member filled with
    268      * an enum value specifying a field.  On output, the FieldPosition will be filled
    269      * in with the text offsets for that field.
    270      * <P> For example, given a time text
    271      * "1996.07.10 AD at 15:08:56 PDT", if the given fieldPosition.field is
    272      * UDAT_YEAR_FIELD, the offsets fieldPosition.beginIndex and
    273      * statfieldPositionus.getEndIndex will be set to 0 and 4, respectively.
    274      * <P> Notice
    275      * that if the same time field appears more than once in a pattern, the status will
    276      * be set for the first occurence of that time field. For instance,
    277      * formatting a UDate to the time string "1 PM PDT (Pacific Daylight Time)"
    278      * using the pattern "h a z (zzzz)" and the alignment field
    279      * DateFormat::TIMEZONE_FIELD, the offsets fieldPosition.beginIndex and
    280      * fieldPosition.getEndIndex will be set to 5 and 8, respectively, for the first
    281      * occurence of the timezone pattern character 'z'.
    282      *
    283      * @param cal           Calendar set to the date and time to be formatted
    284      *                      into a date/time string.  When the calendar type is
    285      *                      different from the internal calendar held by this
    286      *                      DateFormat instance, the date and the time zone will
    287      *                      be inherited from the input calendar, but other calendar
    288      *                      field values will be calculated by the internal calendar.
    289      * @param appendTo      Output parameter to receive result.
    290      *                      Result is appended to existing contents.
    291      * @param fieldPosition On input: an alignment field, if desired (see examples above)
    292      *                      On output: the offsets of the alignment field (see examples above)
    293      * @return              Reference to 'appendTo' parameter.
    294      * @stable ICU 2.1
    295      */
    296     virtual UnicodeString& format(  Calendar& cal,
    297                                     UnicodeString& appendTo,
    298                                     FieldPosition& fieldPosition) const = 0;
    299 
    300     /**
    301      * Formats a date into a date/time string. Subclasses should implement this method.
    302      *
    303      * @param cal       Calendar set to the date and time to be formatted
    304      *                  into a date/time string.  When the calendar type is
    305      *                  different from the internal calendar held by this
    306      *                  DateFormat instance, the date and the time zone will
    307      *                  be inherited from the input calendar, but other calendar
    308      *                  field values will be calculated by the internal calendar.
    309      * @param appendTo  Output parameter to receive result.
    310      *                  Result is appended to existing contents.
    311      * @param posIter   On return, can be used to iterate over positions
    312      *                  of fields generated by this format call.  Field values
    313      *                  are defined in UDateFormatField.  Can be NULL.
    314      * @param status    error status.
    315      * @return          Reference to 'appendTo' parameter.
    316      * @stable ICU 4.4
    317      */
    318     virtual UnicodeString& format(Calendar& cal,
    319                                   UnicodeString& appendTo,
    320                                   FieldPositionIterator* posIter,
    321                                   UErrorCode& status) const;
    322     /**
    323      * Formats a UDate into a date/time string.
    324      * <P>
    325      * On input, the FieldPosition parameter may have its "field" member filled with
    326      * an enum value specifying a field.  On output, the FieldPosition will be filled
    327      * in with the text offsets for that field.
    328      * <P> For example, given a time text
    329      * "1996.07.10 AD at 15:08:56 PDT", if the given fieldPosition.field is
    330      * UDAT_YEAR_FIELD, the offsets fieldPosition.beginIndex and
    331      * statfieldPositionus.getEndIndex will be set to 0 and 4, respectively.
    332      * <P> Notice
    333      * that if the same time field appears more than once in a pattern, the status will
    334      * be set for the first occurence of that time field. For instance,
    335      * formatting a UDate to the time string "1 PM PDT (Pacific Daylight Time)"
    336      * using the pattern "h a z (zzzz)" and the alignment field
    337      * DateFormat::TIMEZONE_FIELD, the offsets fieldPosition.beginIndex and
    338      * fieldPosition.getEndIndex will be set to 5 and 8, respectively, for the first
    339      * occurence of the timezone pattern character 'z'.
    340      *
    341      * @param date          UDate to be formatted into a date/time string.
    342      * @param appendTo      Output parameter to receive result.
    343      *                      Result is appended to existing contents.
    344      * @param fieldPosition On input: an alignment field, if desired (see examples above)
    345      *                      On output: the offsets of the alignment field (see examples above)
    346      * @return              Reference to 'appendTo' parameter.
    347      * @stable ICU 2.0
    348      */
    349     UnicodeString& format(  UDate date,
    350                             UnicodeString& appendTo,
    351                             FieldPosition& fieldPosition) const;
    352 
    353     /**
    354      * Formats a UDate into a date/time string.
    355      *
    356      * @param date      UDate to be formatted into a date/time string.
    357      * @param appendTo  Output parameter to receive result.
    358      *                  Result is appended to existing contents.
    359      * @param posIter   On return, can be used to iterate over positions
    360      *                  of fields generated by this format call.  Field values
    361      *                  are defined in UDateFormatField.  Can be NULL.
    362      * @param status    error status.
    363      * @return          Reference to 'appendTo' parameter.
    364      * @stable ICU 4.4
    365      */
    366     UnicodeString& format(UDate date,
    367                           UnicodeString& appendTo,
    368                           FieldPositionIterator* posIter,
    369                           UErrorCode& status) const;
    370     /**
    371      * Formats a UDate into a date/time string. If there is a problem, you won't
    372      * know, using this method. Use the overloaded format() method which takes a
    373      * FieldPosition& to detect formatting problems.
    374      *
    375      * @param date      The UDate value to be formatted into a string.
    376      * @param appendTo  Output parameter to receive result.
    377      *                  Result is appended to existing contents.
    378      * @return          Reference to 'appendTo' parameter.
    379      * @stable ICU 2.0
    380      */
    381     UnicodeString& format(UDate date, UnicodeString& appendTo) const;
    382 
    383     /**
    384      * Parse a date/time string. For example, a time text "07/10/96 4:5 PM, PDT"
    385      * will be parsed into a UDate that is equivalent to Date(837039928046).
    386      * Parsing begins at the beginning of the string and proceeds as far as
    387      * possible.  Assuming no parse errors were encountered, this function
    388      * doesn't return any information about how much of the string was consumed
    389      * by the parsing.  If you need that information, use the version of
    390      * parse() that takes a ParsePosition.
    391      * <P>
    392      * By default, parsing is lenient: If the input is not in the form used by
    393      * this object's format method but can still be parsed as a date, then the
    394      * parse succeeds. Clients may insist on strict adherence to the format by
    395      * calling setLenient(false).
    396      * @see DateFormat::setLenient(boolean)
    397      * <P>
    398      * Note that the normal date formats associated with some calendars - such
    399      * as the Chinese lunar calendar - do not specify enough fields to enable
    400      * dates to be parsed unambiguously. In the case of the Chinese lunar
    401      * calendar, while the year within the current 60-year cycle is specified,
    402      * the number of such cycles since the start date of the calendar (in the
    403      * ERA field of the Calendar object) is not normally part of the format,
    404      * and parsing may assume the wrong era. For cases such as this it is
    405      * recommended that clients parse using the method
    406      * parse(const UnicodeString&, Calendar& cal, ParsePosition&)
    407      * with the Calendar passed in set to the current date, or to a date
    408      * within the era/cycle that should be assumed if absent in the format.
    409      *
    410      * @param text      The date/time string to be parsed into a UDate value.
    411      * @param status    Output param to be set to success/failure code. If
    412      *                  'text' cannot be parsed, it will be set to a failure
    413      *                  code.
    414      * @return          The parsed UDate value, if successful.
    415      * @stable ICU 2.0
    416      */
    417     virtual UDate parse( const UnicodeString& text,
    418                         UErrorCode& status) const;
    419 
    420     /**
    421      * Parse a date/time string beginning at the given parse position. For
    422      * example, a time text "07/10/96 4:5 PM, PDT" will be parsed into a Date
    423      * that is equivalent to Date(837039928046).
    424      * <P>
    425      * By default, parsing is lenient: If the input is not in the form used by
    426      * this object's format method but can still be parsed as a date, then the
    427      * parse succeeds. Clients may insist on strict adherence to the format by
    428      * calling setLenient(false).
    429      * @see DateFormat::setLenient(boolean)
    430      *
    431      * @param text  The date/time string to be parsed.
    432      * @param cal   A Calendar set on input to the date and time to be used for
    433      *              missing values in the date/time string being parsed, and set
    434      *              on output to the parsed date/time. When the calendar type is
    435      *              different from the internal calendar held by this DateFormat
    436      *              instance, the internal calendar will be cloned to a work
    437      *              calendar set to the same milliseconds and time zone as the
    438      *              cal parameter, field values will be parsed based on the work
    439      *              calendar, then the result (milliseconds and time zone) will
    440      *              be set in this calendar.
    441      * @param pos   On input, the position at which to start parsing; on
    442      *              output, the position at which parsing terminated, or the
    443      *              start position if the parse failed.
    444      * @stable ICU 2.1
    445      */
    446     virtual void parse( const UnicodeString& text,
    447                         Calendar& cal,
    448                         ParsePosition& pos) const = 0;
    449 
    450     /**
    451      * Parse a date/time string beginning at the given parse position. For
    452      * example, a time text "07/10/96 4:5 PM, PDT" will be parsed into a Date
    453      * that is equivalent to Date(837039928046).
    454      * <P>
    455      * By default, parsing is lenient: If the input is not in the form used by
    456      * this object's format method but can still be parsed as a date, then the
    457      * parse succeeds. Clients may insist on strict adherence to the format by
    458      * calling setLenient(false).
    459      * @see DateFormat::setLenient(boolean)
    460      * <P>
    461      * Note that the normal date formats associated with some calendars - such
    462      * as the Chinese lunar calendar - do not specify enough fields to enable
    463      * dates to be parsed unambiguously. In the case of the Chinese lunar
    464      * calendar, while the year within the current 60-year cycle is specified,
    465      * the number of such cycles since the start date of the calendar (in the
    466      * ERA field of the Calendar object) is not normally part of the format,
    467      * and parsing may assume the wrong era. For cases such as this it is
    468      * recommended that clients parse using the method
    469      * parse(const UnicodeString&, Calendar& cal, ParsePosition&)
    470      * with the Calendar passed in set to the current date, or to a date
    471      * within the era/cycle that should be assumed if absent in the format.
    472      *
    473      * @param text  The date/time string to be parsed into a UDate value.
    474      * @param pos   On input, the position at which to start parsing; on
    475      *              output, the position at which parsing terminated, or the
    476      *              start position if the parse failed.
    477      * @return      A valid UDate if the input could be parsed.
    478      * @stable ICU 2.0
    479      */
    480     UDate parse( const UnicodeString& text,
    481                  ParsePosition& pos) const;
    482 
    483     /**
    484      * Parse a string to produce an object. This methods handles parsing of
    485      * date/time strings into Formattable objects with UDate types.
    486      * <P>
    487      * Before calling, set parse_pos.index to the offset you want to start
    488      * parsing at in the source. After calling, parse_pos.index is the end of
    489      * the text you parsed. If error occurs, index is unchanged.
    490      * <P>
    491      * When parsing, leading whitespace is discarded (with a successful parse),
    492      * while trailing whitespace is left as is.
    493      * <P>
    494      * See Format::parseObject() for more.
    495      *
    496      * @param source    The string to be parsed into an object.
    497      * @param result    Formattable to be set to the parse result.
    498      *                  If parse fails, return contents are undefined.
    499      * @param parse_pos The position to start parsing at. Upon return
    500      *                  this param is set to the position after the
    501      *                  last character successfully parsed. If the
    502      *                  source is not parsed successfully, this param
    503      *                  will remain unchanged.
    504      * @stable ICU 2.0
    505      */
    506     virtual void parseObject(const UnicodeString& source,
    507                              Formattable& result,
    508                              ParsePosition& parse_pos) const;
    509 
    510     /**
    511      * Create a default date/time formatter that uses the SHORT style for both
    512      * the date and the time.
    513      *
    514      * @return A date/time formatter which the caller owns.
    515      * @stable ICU 2.0
    516      */
    517     static DateFormat* U_EXPORT2 createInstance(void);
    518 
    519     /**
    520      * Creates a time formatter with the given formatting style for the given
    521      * locale.
    522      *
    523      * @param style     The given formatting style. For example,
    524      *                  SHORT for "h:mm a" in the US locale. Relative
    525      *                  time styles are not currently supported.
    526      * @param aLocale   The given locale.
    527      * @return          A time formatter which the caller owns.
    528      * @stable ICU 2.0
    529      */
    530     static DateFormat* U_EXPORT2 createTimeInstance(EStyle style = kDefault,
    531                                           const Locale& aLocale = Locale::getDefault());
    532 
    533     /**
    534      * Creates a date formatter with the given formatting style for the given
    535      * const locale.
    536      *
    537      * @param style     The given formatting style. For example, SHORT for "M/d/yy" in the
    538      *                  US locale. As currently implemented, relative date formatting only
    539      *                  affects a limited range of calendar days before or after the
    540      *                  current date, based on the CLDR &lt;field type="day"&gt;/&lt;relative&gt; data:
    541      *                  For example, in English, "Yesterday", "Today", and "Tomorrow".
    542      *                  Outside of this range, dates are formatted using the corresponding
    543      *                  non-relative style.
    544      * @param aLocale   The given locale.
    545      * @return          A date formatter which the caller owns.
    546      * @stable ICU 2.0
    547      */
    548     static DateFormat* U_EXPORT2 createDateInstance(EStyle style = kDefault,
    549                                           const Locale& aLocale = Locale::getDefault());
    550 
    551     /**
    552      * Creates a date/time formatter with the given formatting styles for the
    553      * given locale.
    554      *
    555      * @param dateStyle The given formatting style for the date portion of the result.
    556      *                  For example, SHORT for "M/d/yy" in the US locale. As currently
    557      *                  implemented, relative date formatting only affects a limited range
    558      *                  of calendar days before or after the current date, based on the
    559      *                  CLDR &lt;field type="day"&gt;/&lt;relative&gt; data: For example, in English,
    560      *                  "Yesterday", "Today", and "Tomorrow". Outside of this range, dates
    561      *                  are formatted using the corresponding non-relative style.
    562      * @param timeStyle The given formatting style for the time portion of the result.
    563      *                  For example, SHORT for "h:mm a" in the US locale. Relative
    564      *                  time styles are not currently supported.
    565      * @param aLocale   The given locale.
    566      * @return          A date/time formatter which the caller owns.
    567      * @stable ICU 2.0
    568      */
    569     static DateFormat* U_EXPORT2 createDateTimeInstance(EStyle dateStyle = kDefault,
    570                                               EStyle timeStyle = kDefault,
    571                                               const Locale& aLocale = Locale::getDefault());
    572 
    573     /**
    574      * Gets the set of locales for which DateFormats are installed.
    575      * @param count Filled in with the number of locales in the list that is returned.
    576      * @return the set of locales for which DateFormats are installed.  The caller
    577      *  does NOT own this list and must not delete it.
    578      * @stable ICU 2.0
    579      */
    580     static const Locale* U_EXPORT2 getAvailableLocales(int32_t& count);
    581 
    582     /**
    583      * Returns true if the encapsulated Calendar object is set for lenient parsing.
    584      * @stable ICU 2.0
    585      */
    586     virtual UBool isLenient(void) const;
    587 
    588     /**
    589      * Specify whether or not date/time parsing is to be lenient. With lenient
    590      * parsing, the parser may use heuristics to interpret inputs that do not
    591      * precisely match this object's format. With strict parsing, inputs must
    592      * match this object's format.
    593      *
    594      * Note: This method is specific to the encapsulated Calendar object.  DateFormat
    595      * leniency aspects are controlled by setBooleanAttribute.
    596      *
    597      * @param lenient  True specifies date/time interpretation to be lenient.
    598      * @see Calendar::setLenient
    599      * @stable ICU 2.0
    600      */
    601     virtual void setLenient(UBool lenient);
    602 
    603     /**
    604      * Gets the calendar associated with this date/time formatter.
    605      * @return the calendar associated with this date/time formatter.
    606      * @stable ICU 2.0
    607      */
    608     virtual const Calendar* getCalendar(void) const;
    609 
    610     /**
    611      * Set the calendar to be used by this date format. Initially, the default
    612      * calendar for the specified or default locale is used.  The caller should
    613      * not delete the Calendar object after it is adopted by this call.
    614      * Adopting a new calendar will change to the default symbols.
    615      *
    616      * @param calendarToAdopt    Calendar object to be adopted.
    617      * @stable ICU 2.0
    618      */
    619     virtual void adoptCalendar(Calendar* calendarToAdopt);
    620 
    621     /**
    622      * Set the calendar to be used by this date format. Initially, the default
    623      * calendar for the specified or default locale is used.
    624      *
    625      * @param newCalendar Calendar object to be set.
    626      * @stable ICU 2.0
    627      */
    628     virtual void setCalendar(const Calendar& newCalendar);
    629 
    630 
    631     /**
    632      * Gets the number formatter which this date/time formatter uses to format
    633      * and parse the numeric portions of the pattern.
    634      * @return the number formatter which this date/time formatter uses.
    635      * @stable ICU 2.0
    636      */
    637     virtual const NumberFormat* getNumberFormat(void) const;
    638 
    639     /**
    640      * Allows you to set the number formatter.  The caller should
    641      * not delete the NumberFormat object after it is adopted by this call.
    642      * @param formatToAdopt     NumberFormat object to be adopted.
    643      * @stable ICU 2.0
    644      */
    645     virtual void adoptNumberFormat(NumberFormat* formatToAdopt);
    646 
    647     /**
    648      * Allows you to set the number formatter.
    649      * @param newNumberFormat  NumberFormat object to be set.
    650      * @stable ICU 2.0
    651      */
    652     virtual void setNumberFormat(const NumberFormat& newNumberFormat);
    653 
    654     /**
    655      * Returns a reference to the TimeZone used by this DateFormat's calendar.
    656      * @return the time zone associated with the calendar of DateFormat.
    657      * @stable ICU 2.0
    658      */
    659     virtual const TimeZone& getTimeZone(void) const;
    660 
    661     /**
    662      * Sets the time zone for the calendar of this DateFormat object. The caller
    663      * no longer owns the TimeZone object and should not delete it after this call.
    664      * @param zoneToAdopt the TimeZone to be adopted.
    665      * @stable ICU 2.0
    666      */
    667     virtual void adoptTimeZone(TimeZone* zoneToAdopt);
    668 
    669     /**
    670      * Sets the time zone for the calendar of this DateFormat object.
    671      * @param zone the new time zone.
    672      * @stable ICU 2.0
    673      */
    674     virtual void setTimeZone(const TimeZone& zone);
    675 
    676    /**
    677      * Set an boolean attribute on this DateFormat.
    678      * May return U_UNSUPPORTED_ERROR if this instance does not support
    679      * the specified attribute.
    680      * @param attr the attribute to set
    681      * @param newvalue new value
    682      * @param status the error type
    683      * @return *this - for chaining (example: format.setAttribute(...).setAttribute(...) )
    684      * @internal ICU technology preview
    685      */
    686 
    687     virtual DateFormat&  U_EXPORT2 setBooleanAttribute(UDateFormatBooleanAttribute attr,
    688     									UBool newvalue,
    689     									UErrorCode &status);
    690 
    691     /**
    692      * Get an boolean from this DateFormat
    693      * May return U_UNSUPPORTED_ERROR if this instance does not support
    694      * the specified attribute.
    695      * @param attr the attribute to set
    696      * @param status the error type
    697      * @return the attribute value. Undefined if there is an error.
    698      * @internal ICU technology preview
    699      */
    700     virtual UBool U_EXPORT2 getBooleanAttribute(UDateFormatBooleanAttribute attr, UErrorCode &status) const;
    701 
    702 protected:
    703     /**
    704      * Default constructor.  Creates a DateFormat with no Calendar or NumberFormat
    705      * associated with it.  This constructor depends on the subclasses to fill in
    706      * the calendar and numberFormat fields.
    707      * @stable ICU 2.0
    708      */
    709     DateFormat();
    710 
    711     /**
    712      * Copy constructor.
    713      * @stable ICU 2.0
    714      */
    715     DateFormat(const DateFormat&);
    716 
    717     /**
    718      * Default assignment operator.
    719      * @stable ICU 2.0
    720      */
    721     DateFormat& operator=(const DateFormat&);
    722 
    723     /**
    724      * The calendar that DateFormat uses to produce the time field values needed
    725      * to implement date/time formatting. Subclasses should generally initialize
    726      * this to the default calendar for the locale associated with this DateFormat.
    727      * @stable ICU 2.4
    728      */
    729     Calendar* fCalendar;
    730 
    731     /**
    732      * The number formatter that DateFormat uses to format numbers in dates and
    733      * times. Subclasses should generally initialize this to the default number
    734      * format for the locale associated with this DateFormat.
    735      * @stable ICU 2.4
    736      */
    737     NumberFormat* fNumberFormat;
    738 
    739 
    740 private:
    741     /**
    742      * Gets the date/time formatter with the given formatting styles for the
    743      * given locale.
    744      * @param dateStyle the given date formatting style.
    745      * @param timeStyle the given time formatting style.
    746      * @param inLocale the given locale.
    747      * @return a date/time formatter, or 0 on failure.
    748      */
    749     static DateFormat* U_EXPORT2 create(EStyle timeStyle, EStyle dateStyle, const Locale& inLocale);
    750 
    751 
    752     /**
    753      * enum set of active boolean attributes for this instance
    754      */
    755     EnumSet<UDateFormatBooleanAttribute, 0, UDAT_BOOLEAN_ATTRIBUTE_COUNT> fBoolFlags;
    756 
    757 
    758 public:
    759 #ifndef U_HIDE_OBSOLETE_API
    760     /**
    761      * Field selector for FieldPosition for DateFormat fields.
    762      * @obsolete ICU 3.4 use UDateFormatField instead, since this API will be
    763      * removed in that release
    764      */
    765     enum EField
    766     {
    767         // Obsolete; use UDateFormatField instead
    768         kEraField = UDAT_ERA_FIELD,
    769         kYearField = UDAT_YEAR_FIELD,
    770         kMonthField = UDAT_MONTH_FIELD,
    771         kDateField = UDAT_DATE_FIELD,
    772         kHourOfDay1Field = UDAT_HOUR_OF_DAY1_FIELD,
    773         kHourOfDay0Field = UDAT_HOUR_OF_DAY0_FIELD,
    774         kMinuteField = UDAT_MINUTE_FIELD,
    775         kSecondField = UDAT_SECOND_FIELD,
    776         kMillisecondField = UDAT_FRACTIONAL_SECOND_FIELD,
    777         kDayOfWeekField = UDAT_DAY_OF_WEEK_FIELD,
    778         kDayOfYearField = UDAT_DAY_OF_YEAR_FIELD,
    779         kDayOfWeekInMonthField = UDAT_DAY_OF_WEEK_IN_MONTH_FIELD,
    780         kWeekOfYearField = UDAT_WEEK_OF_YEAR_FIELD,
    781         kWeekOfMonthField = UDAT_WEEK_OF_MONTH_FIELD,
    782         kAmPmField = UDAT_AM_PM_FIELD,
    783         kHour1Field = UDAT_HOUR1_FIELD,
    784         kHour0Field = UDAT_HOUR0_FIELD,
    785         kTimezoneField = UDAT_TIMEZONE_FIELD,
    786         kYearWOYField = UDAT_YEAR_WOY_FIELD,
    787         kDOWLocalField = UDAT_DOW_LOCAL_FIELD,
    788         kExtendedYearField = UDAT_EXTENDED_YEAR_FIELD,
    789         kJulianDayField = UDAT_JULIAN_DAY_FIELD,
    790         kMillisecondsInDayField = UDAT_MILLISECONDS_IN_DAY_FIELD,
    791 
    792         // Obsolete; use UDateFormatField instead
    793         ERA_FIELD = UDAT_ERA_FIELD,
    794         YEAR_FIELD = UDAT_YEAR_FIELD,
    795         MONTH_FIELD = UDAT_MONTH_FIELD,
    796         DATE_FIELD = UDAT_DATE_FIELD,
    797         HOUR_OF_DAY1_FIELD = UDAT_HOUR_OF_DAY1_FIELD,
    798         HOUR_OF_DAY0_FIELD = UDAT_HOUR_OF_DAY0_FIELD,
    799         MINUTE_FIELD = UDAT_MINUTE_FIELD,
    800         SECOND_FIELD = UDAT_SECOND_FIELD,
    801         MILLISECOND_FIELD = UDAT_FRACTIONAL_SECOND_FIELD,
    802         DAY_OF_WEEK_FIELD = UDAT_DAY_OF_WEEK_FIELD,
    803         DAY_OF_YEAR_FIELD = UDAT_DAY_OF_YEAR_FIELD,
    804         DAY_OF_WEEK_IN_MONTH_FIELD = UDAT_DAY_OF_WEEK_IN_MONTH_FIELD,
    805         WEEK_OF_YEAR_FIELD = UDAT_WEEK_OF_YEAR_FIELD,
    806         WEEK_OF_MONTH_FIELD = UDAT_WEEK_OF_MONTH_FIELD,
    807         AM_PM_FIELD = UDAT_AM_PM_FIELD,
    808         HOUR1_FIELD = UDAT_HOUR1_FIELD,
    809         HOUR0_FIELD = UDAT_HOUR0_FIELD,
    810         TIMEZONE_FIELD = UDAT_TIMEZONE_FIELD
    811     };
    812 #endif  /* U_HIDE_OBSOLETE_API */
    813 };
    814 
    815 U_NAMESPACE_END
    816 
    817 #endif /* #if !UCONFIG_NO_FORMATTING */
    818 
    819 #endif // _DATEFMT
    820 //eof
    821