1/********************************************************************************
2* Copyright (C) 2008-2010, International Business Machines Corporation and
3* others. All Rights Reserved.
4*******************************************************************************
5*
6* File DTITVFMT.H
7*
8*******************************************************************************
9*/
10
11#ifndef __DTITVFMT_H__
12#define __DTITVFMT_H__
13
14
15#include "unicode/utypes.h"
16
17/**
18 * \file
19 * \brief C++ API: Format and parse date interval in a language-independent manner.
20 */
21
22#if !UCONFIG_NO_FORMATTING
23
24#include "unicode/ucal.h"
25#include "unicode/smpdtfmt.h"
26#include "unicode/dtintrv.h"
27#include "unicode/dtitvinf.h"
28#include "unicode/dtptngen.h"
29
30U_NAMESPACE_BEGIN
31
32
33
34/**
35 * DateIntervalFormat is a class for formatting and parsing date
36 * intervals in a language-independent manner.
37 * Only formatting is supported, parsing is not supported.
38 *
39 * <P>
40 * Date interval means from one date to another date,
41 * for example, from "Jan 11, 2008" to "Jan 18, 2008".
42 * We introduced class DateInterval to represent it.
43 * DateInterval is a pair of UDate, which is
44 * the standard milliseconds since 24:00 GMT, Jan 1, 1970.
45 *
46 * <P>
47 * DateIntervalFormat formats a DateInterval into
48 * text as compactly as possible.
49 * For example, the date interval format from "Jan 11, 2008" to "Jan 18,. 2008"
50 * is "Jan 11-18, 2008" for English.
51 * And it parses text into DateInterval,
52 * although initially, parsing is not supported.
53 *
54 * <P>
55 * There is no structural information in date time patterns.
56 * For any punctuations and string literals inside a date time pattern,
57 * we do not know whether it is just a separator, or a prefix, or a suffix.
58 * Without such information, so, it is difficult to generate a sub-pattern
59 * (or super-pattern) by algorithm.
60 * So, formatting a DateInterval is pattern-driven. It is very
61 * similar to formatting in SimpleDateFormat.
62 * We introduce class DateIntervalInfo to save date interval
63 * patterns, similar to date time pattern in SimpleDateFormat.
64 *
65 * <P>
66 * Logically, the interval patterns are mappings
67 * from (skeleton, the_largest_different_calendar_field)
68 * to (date_interval_pattern).
69 *
70 * <P>
71 * A skeleton
72 * <ol>
73 * <li>
74 * only keeps the field pattern letter and ignores all other parts
75 * in a pattern, such as space, punctuations, and string literals.
76 * </li>
77 * <li>
78 * hides the order of fields.
79 * </li>
80 * <li>
81 * might hide a field's pattern letter length.
82 * </li>
83 * </ol>
84 *
85 * For those non-digit calendar fields, the pattern letter length is
86 * important, such as MMM, MMMM, and MMMMM; EEE and EEEE,
87 * and the field's pattern letter length is honored.
88 *
89 * For the digit calendar fields,  such as M or MM, d or dd, yy or yyyy,
90 * the field pattern length is ignored and the best match, which is defined
91 * in date time patterns, will be returned without honor the field pattern
92 * letter length in skeleton.
93 *
94 * <P>
95 * The calendar fields we support for interval formatting are:
96 * year, month, date, day-of-week, am-pm, hour, hour-of-day, and minute.
97 * Those calendar fields can be defined in the following order:
98 * year >  month > date > hour (in day) >  minute
99 *
100 * The largest different calendar fields between 2 calendars is the
101 * first different calendar field in above order.
102 *
103 * For example: the largest different calendar fields between "Jan 10, 2007"
104 * and "Feb 20, 2008" is year.
105 *
106 * <P>
107 * For other calendar fields, the compact interval formatting is not
108 * supported. And the interval format will be fall back to fall-back
109 * patterns, which is mostly "{date0} - {date1}".
110 *
111 * <P>
112 * There is a set of pre-defined static skeleton strings.
113 * There are pre-defined interval patterns for those pre-defined skeletons
114 * in locales' resource files.
115 * For example, for a skeleton UDAT_YEAR_ABBR_MONTH_DAY, which is  &quot;yMMMd&quot;,
116 * in  en_US, if the largest different calendar field between date1 and date2
117 * is &quot;year&quot;, the date interval pattern  is &quot;MMM d, yyyy - MMM d, yyyy&quot;,
118 * such as &quot;Jan 10, 2007 - Jan 10, 2008&quot;.
119 * If the largest different calendar field between date1 and date2 is &quot;month&quot;,
120 * the date interval pattern is &quot;MMM d - MMM d, yyyy&quot;,
121 * such as &quot;Jan 10 - Feb 10, 2007&quot;.
122 * If the largest different calendar field between date1 and date2 is &quot;day&quot;,
123 * the date interval pattern is &quot;MMM d-d, yyyy&quot;, such as &quot;Jan 10-20, 2007&quot;.
124 *
125 * For date skeleton, the interval patterns when year, or month, or date is
126 * different are defined in resource files.
127 * For time skeleton, the interval patterns when am/pm, or hour, or minute is
128 * different are defined in resource files.
129 *
130 * <P>
131 * If a skeleton is not found in a locale's DateIntervalInfo, which means
132 * the interval patterns for the skeleton is not defined in resource file,
133 * the interval pattern will falls back to the interval "fallback" pattern
134 * defined in resource file.
135 * If the interval "fallback" pattern is not defined, the default fall-back
136 * is "{date0} - {data1}".
137 *
138 * <P>
139 * For the combination of date and time,
140 * The rule to generate interval patterns are:
141 * <ol>
142 * <li>
143 *    when the year, month, or day differs, falls back to fall-back
144 *    interval pattern, which mostly is the concatenate the two original
145 *    expressions with a separator between,
146 *    For example, interval pattern from "Jan 10, 2007 10:10 am"
147 *    to "Jan 11, 2007 10:10am" is
148 *    "Jan 10, 2007 10:10 am - Jan 11, 2007 10:10am"
149 * </li>
150 * <li>
151 *    otherwise, present the date followed by the range expression
152 *    for the time.
153 *    For example, interval pattern from "Jan 10, 2007 10:10 am"
154 *    to "Jan 10, 2007 11:10am" is "Jan 10, 2007 10:10 am - 11:10am"
155 * </li>
156 * </ol>
157 *
158 *
159 * <P>
160 * If two dates are the same, the interval pattern is the single date pattern.
161 * For example, interval pattern from "Jan 10, 2007" to "Jan 10, 2007" is
162 * "Jan 10, 2007".
163 *
164 * Or if the presenting fields between 2 dates have the exact same values,
165 * the interval pattern is the  single date pattern.
166 * For example, if user only requests year and month,
167 * the interval pattern from "Jan 10, 2007" to "Jan 20, 2007" is "Jan 2007".
168 *
169 * <P>
170 * DateIntervalFormat needs the following information for correct
171 * formatting: time zone, calendar type, pattern, date format symbols,
172 * and date interval patterns.
173 * It can be instantiated in 2 ways:
174 * <ol>
175 * <li>
176 *    create an instance using default or given locale plus given skeleton.
177 *    Users are encouraged to created date interval formatter this way and
178 *    to use the pre-defined skeleton macros, such as
179 *    UDAT_YEAR_NUM_MONTH, which consists the calendar fields and
180 *    the format style.
181 * </li>
182 * <li>
183 *    create an instance using default or given locale plus given skeleton
184 *    plus a given DateIntervalInfo.
185 *    This factory method is for powerful users who want to provide their own
186 *    interval patterns.
187 *    Locale provides the timezone, calendar, and format symbols information.
188 *    Local plus skeleton provides full pattern information.
189 *    DateIntervalInfo provides the date interval patterns.
190 * </li>
191 * </ol>
192 *
193 * <P>
194 * For the calendar field pattern letter, such as G, y, M, d, a, h, H, m, s etc.
195 * DateIntervalFormat uses the same syntax as that of
196 * DateTime format.
197 *
198 * <P>
199 * Code Sample: general usage
200 * <pre>
201 * \code
202 *   // the date interval object which the DateIntervalFormat formats on
203 *   // and parses into
204 *   DateInterval*  dtInterval = new DateInterval(1000*3600*24, 1000*3600*24*2);
205 *   UErrorCode status = U_ZERO_ERROR;
206 *   DateIntervalFormat* dtIntervalFmt = DateIntervalFormat::createInstance(
207 *                           UDAT_YEAR_MONTH_DAY,
208 *                           Locale("en", "GB", ""), status);
209 *   UnicodeUnicodeString dateIntervalString;
210 *   FieldPosition pos = 0;
211 *   // formatting
212 *   dtIntervalFmt->format(dtInterval, dateIntervalUnicodeString, pos, status);
213 *   delete dtIntervalFmt;
214 * \endcode
215 * </pre>
216 */
217
218class U_I18N_API DateIntervalFormat : public Format {
219public:
220
221    /**
222     * Construct a DateIntervalFormat from skeleton and  the default locale.
223     *
224     * This is a convenient override of
225     * createInstance(const UnicodeString& skeleton, const Locale& locale,
226     *                UErrorCode&)
227     * with the value of locale as default locale.
228     *
229     * @param skeleton  the skeleton on which interval format based.
230     * @param status    output param set to success/failure code on exit
231     * @return          a date time interval formatter which the caller owns.
232     * @stable ICU 4.0
233     */
234    static DateIntervalFormat* U_EXPORT2 createInstance(
235                                               const UnicodeString& skeleton,
236                                               UErrorCode& status);
237
238    /**
239     * Construct a DateIntervalFormat from skeleton and a given locale.
240     * <P>
241     * In this factory method,
242     * the date interval pattern information is load from resource files.
243     * Users are encouraged to created date interval formatter this way and
244     * to use the pre-defined skeleton macros.
245     *
246     * <P>
247     * There are pre-defined skeletons (defined in udate.h) having predefined
248     * interval patterns in resource files.
249     * Users are encouraged to use those macros.
250     * For example:
251     * DateIntervalFormat::createInstance(UDAT_MONTH_DAY, status)
252     *
253     * The given Locale provides the interval patterns.
254     * For example, for en_GB, if skeleton is UDAT_YEAR_ABBR_MONTH_WEEKDAY_DAY,
255     * which is "yMMMEEEd",
256     * the interval patterns defined in resource file to above skeleton are:
257     * "EEE, d MMM, yyyy - EEE, d MMM, yyyy" for year differs,
258     * "EEE, d MMM - EEE, d MMM, yyyy" for month differs,
259     * "EEE, d - EEE, d MMM, yyyy" for day differs,
260     * @param skeleton  the skeleton on which interval format based.
261     * @param locale    the given locale
262     * @param status    output param set to success/failure code on exit
263     * @return          a date time interval formatter which the caller owns.
264     * @stable ICU 4.0
265     */
266
267    static DateIntervalFormat* U_EXPORT2 createInstance(
268                                               const UnicodeString& skeleton,
269                                               const Locale& locale,
270                                               UErrorCode& status);
271
272    /**
273     * Construct a DateIntervalFormat from skeleton
274     *  DateIntervalInfo, and default locale.
275     *
276     * This is a convenient override of
277     * createInstance(const UnicodeString& skeleton, const Locale& locale,
278     *                const DateIntervalInfo& dtitvinf, UErrorCode&)
279     * with the locale value as default locale.
280     *
281     * @param skeleton  the skeleton on which interval format based.
282     * @param dtitvinf  the DateIntervalInfo object.
283     * @param status    output param set to success/failure code on exit
284     * @return          a date time interval formatter which the caller owns.
285     * @stable ICU 4.0
286     */
287    static DateIntervalFormat* U_EXPORT2 createInstance(
288                                              const UnicodeString& skeleton,
289                                              const DateIntervalInfo& dtitvinf,
290                                              UErrorCode& status);
291
292    /**
293     * Construct a DateIntervalFormat from skeleton
294     * a DateIntervalInfo, and the given locale.
295     *
296     * <P>
297     * In this factory method, user provides its own date interval pattern
298     * information, instead of using those pre-defined data in resource file.
299     * This factory method is for powerful users who want to provide their own
300     * interval patterns.
301     * <P>
302     * There are pre-defined skeletons (defined in udate.h) having predefined
303     * interval patterns in resource files.
304     * Users are encouraged to use those macros.
305     * For example:
306     * DateIntervalFormat::createInstance(UDAT_MONTH_DAY, status)
307     *
308     * The DateIntervalInfo provides the interval patterns.
309     * and the DateIntervalInfo ownership remains to the caller.
310     *
311     * User are encouraged to set default interval pattern in DateIntervalInfo
312     * as well, if they want to set other interval patterns ( instead of
313     * reading the interval patterns from resource files).
314     * When the corresponding interval pattern for a largest calendar different
315     * field is not found ( if user not set it ), interval format fallback to
316     * the default interval pattern.
317     * If user does not provide default interval pattern, it fallback to
318     * "{date0} - {date1}"
319     *
320     * @param skeleton  the skeleton on which interval format based.
321     * @param locale    the given locale
322     * @param dtitvinf  the DateIntervalInfo object.
323     * @param status    output param set to success/failure code on exit
324     * @return          a date time interval formatter which the caller owns.
325     * @stable ICU 4.0
326     */
327    static DateIntervalFormat* U_EXPORT2 createInstance(
328                                              const UnicodeString& skeleton,
329                                              const Locale& locale,
330                                              const DateIntervalInfo& dtitvinf,
331                                              UErrorCode& status);
332
333    /**
334     * Destructor.
335     * @stable ICU 4.0
336     */
337    virtual ~DateIntervalFormat();
338
339    /**
340     * Clone this Format object polymorphically. The caller owns the result and
341     * should delete it when done.
342     * @return    A copy of the object.
343     * @stable ICU 4.0
344     */
345    virtual Format* clone(void) const;
346
347    /**
348     * Return true if the given Format objects are semantically equal. Objects
349     * of different subclasses are considered unequal.
350     * @param other    the object to be compared with.
351     * @return         true if the given Format objects are semantically equal.
352     * @stable ICU 4.0
353     */
354    virtual UBool operator==(const Format& other) const;
355
356    /**
357     * Return true if the given Format objects are not semantically equal.
358     * Objects of different subclasses are considered unequal.
359     * @param other the object to be compared with.
360     * @return      true if the given Format objects are not semantically equal.
361     * @stable ICU 4.0
362     */
363    UBool operator!=(const Format& other) const;
364
365
366    using Format::format;
367
368    /**
369     * Format an object to produce a string. This method handles Formattable
370     * objects with a DateInterval type.
371     * If a the Formattable object type is not a DateInterval,
372     * then it returns a failing UErrorCode.
373     *
374     * @param obj               The object to format.
375     *                          Must be a DateInterval.
376     * @param appendTo          Output parameter to receive result.
377     *                          Result is appended to existing contents.
378     * @param fieldPosition     On input: an alignment field, if desired.
379     *                          On output: the offsets of the alignment field.
380     * @param status            Output param filled with success/failure status.
381     * @return                  Reference to 'appendTo' parameter.
382     * @stable ICU 4.0
383     */
384    virtual UnicodeString& format(const Formattable& obj,
385                                  UnicodeString& appendTo,
386                                  FieldPosition& fieldPosition,
387                                  UErrorCode& status) const ;
388
389
390
391    /**
392     * Format a DateInterval to produce a string.
393     *
394     * @param dtInterval        DateInterval to be formatted.
395     * @param appendTo          Output parameter to receive result.
396     *                          Result is appended to existing contents.
397     * @param fieldPosition     On input: an alignment field, if desired.
398     *                          On output: the offsets of the alignment field.
399     * @param status            Output param filled with success/failure status.
400     * @return                  Reference to 'appendTo' parameter.
401     * @stable ICU 4.0
402     */
403    UnicodeString& format(const DateInterval* dtInterval,
404                          UnicodeString& appendTo,
405                          FieldPosition& fieldPosition,
406                          UErrorCode& status) const ;
407
408
409    /**
410     * Format 2 Calendars to produce a string.
411     *
412     * Note: "fromCalendar" and "toCalendar" are not const,
413     * since calendar is not const in  SimpleDateFormat::format(Calendar&),
414     *
415     * @param fromCalendar      calendar set to the from date in date interval
416     *                          to be formatted into date interval string
417     * @param toCalendar        calendar set to the to date in date interval
418     *                          to be formatted into date interval string
419     * @param appendTo          Output parameter to receive result.
420     *                          Result is appended to existing contents.
421     * @param fieldPosition     On input: an alignment field, if desired.
422     *                          On output: the offsets of the alignment field.
423     * @param status            Output param filled with success/failure status.
424     *                          Caller needs to make sure it is SUCCESS
425     *                          at the function entrance
426     * @return                  Reference to 'appendTo' parameter.
427     * @stable ICU 4.0
428     */
429    UnicodeString& format(Calendar& fromCalendar,
430                          Calendar& toCalendar,
431                          UnicodeString& appendTo,
432                          FieldPosition& fieldPosition,
433                          UErrorCode& status) const ;
434
435    /**
436     * Date interval parsing is not supported. Please do not use.
437     * <P>
438     * This method should handle parsing of
439     * date time interval strings into Formattable objects with
440     * DateInterval type, which is a pair of UDate.
441     * <P>
442     * Before calling, set parse_pos.index to the offset you want to start
443     * parsing at in the source. After calling, parse_pos.index is the end of
444     * the text you parsed. If error occurs, index is unchanged.
445     * <P>
446     * When parsing, leading whitespace is discarded (with a successful parse),
447     * while trailing whitespace is left as is.
448     * <P>
449     * See Format::parseObject() for more.
450     *
451     * @param source    The string to be parsed into an object.
452     * @param result    Formattable to be set to the parse result.
453     *                  If parse fails, return contents are undefined.
454     * @param parse_pos The position to start parsing at. Since no parsing
455     *                  is supported, upon return this param is unchanged.
456     * @return          A newly created Formattable* object, or NULL
457     *                  on failure.  The caller owns this and should
458     *                  delete it when done.
459     * @internal ICU 4.0
460     */
461    virtual void parseObject(const UnicodeString& source,
462                             Formattable& result,
463                             ParsePosition& parse_pos) const;
464
465
466    /**
467     * Gets the date time interval patterns.
468     * @return the date time interval patterns associated with
469     * this date interval formatter.
470     * @stable ICU 4.0
471     */
472    const DateIntervalInfo* getDateIntervalInfo(void) const;
473
474
475    /**
476     * Set the date time interval patterns.
477     * @param newIntervalPatterns   the given interval patterns to copy.
478     * @param status          output param set to success/failure code on exit
479     * @stable ICU 4.0
480     */
481    void setDateIntervalInfo(const DateIntervalInfo& newIntervalPatterns,
482                             UErrorCode& status);
483
484
485    /**
486     * Gets the date formatter
487     * @return the date formatter associated with this date interval formatter.
488     * @stable ICU 4.0
489     */
490    const DateFormat* getDateFormat(void) const;
491
492    /**
493     * Return the class ID for this class. This is useful only for comparing to
494     * a return value from getDynamicClassID(). For example:
495     * <pre>
496     * .   Base* polymorphic_pointer = createPolymorphicObject();
497     * .   if (polymorphic_pointer->getDynamicClassID() ==
498     * .       erived::getStaticClassID()) ...
499     * </pre>
500     * @return          The class ID for all objects of this class.
501     * @stable ICU 4.0
502     */
503    static UClassID U_EXPORT2 getStaticClassID(void);
504
505    /**
506     * Returns a unique class ID POLYMORPHICALLY. Pure virtual override. This
507     * method is to implement a simple version of RTTI, since not all C++
508     * compilers support genuine RTTI. Polymorphic operator==() and clone()
509     * methods call this method.
510     *
511     * @return          The class ID for this object. All objects of a
512     *                  given class have the same class ID.  Objects of
513     *                  other classes have different class IDs.
514     * @stable ICU 4.0
515     */
516    virtual UClassID getDynamicClassID(void) const;
517
518protected:
519
520    /**
521     * Copy constructor.
522     * @stable ICU 4.0
523     */
524    DateIntervalFormat(const DateIntervalFormat&);
525
526    /**
527     * Assignment operator.
528     * @stable ICU 4.0
529     */
530    DateIntervalFormat& operator=(const DateIntervalFormat&);
531
532private:
533
534    /*
535     * This is for ICU internal use only. Please do not use.
536     * Save the interval pattern information.
537     * Interval pattern consists of 2 single date patterns and the separator.
538     * For example, interval pattern "MMM d - MMM d, yyyy" consists
539     * a single date pattern "MMM d", another single date pattern "MMM d, yyyy",
540     * and a separator "-".
541     * The pattern is divided into 2 parts. For above example,
542     * the first part is "MMM d - ", and the second part is "MMM d, yyyy".
543     * Also, the first date appears in an interval pattern could be
544     * the earlier date or the later date.
545     * And such information is saved in the interval pattern as well.
546     * @internal ICU 4.0
547     */
548    struct PatternInfo {
549        UnicodeString firstPart;
550        UnicodeString secondPart;
551        /**
552         * Whether the first date in interval pattern is later date or not.
553         * Fallback format set the default ordering.
554         * And for a particular interval pattern, the order can be
555         * overriden by prefixing the interval pattern with "latestFirst:" or
556         * "earliestFirst:"
557         * For example, given 2 date, Jan 10, 2007 to Feb 10, 2007.
558         * if the fallback format is "{0} - {1}",
559         * and the pattern is "d MMM - d MMM yyyy", the interval format is
560         * "10 Jan - 10 Feb, 2007".
561         * If the pattern is "latestFirst:d MMM - d MMM yyyy",
562         * the interval format is "10 Feb - 10 Jan, 2007"
563         */
564        UBool         laterDateFirst;
565    };
566
567
568    /**
569     * default constructor
570     * @internal ICU 4.0
571     */
572    DateIntervalFormat();
573
574    /**
575     * Construct a DateIntervalFormat from DateFormat,
576     * a DateIntervalInfo, and skeleton.
577     * DateFormat provides the timezone, calendar,
578     * full pattern, and date format symbols information.
579     * It should be a SimpleDateFormat object which
580     * has a pattern in it.
581     * the DateIntervalInfo provides the interval patterns.
582     *
583     * Note: the DateIntervalFormat takes ownership of both
584     * DateFormat and DateIntervalInfo objects.
585     * Caller should not delete them.
586     *
587     * @param locale    the locale of this date interval formatter.
588     * @param dtitvinf  the DateIntervalInfo object to be adopted.
589     * @param skeleton  the skeleton of the date formatter
590     * @param status    output param set to success/failure code on exit
591     * @internal ICU 4.0
592     */
593    DateIntervalFormat(const Locale& locale, DateIntervalInfo* dtItvInfo,
594                       const UnicodeString* skeleton, UErrorCode& status);
595
596
597    /**
598     * Construct a DateIntervalFormat from DateFormat
599     * and a DateIntervalInfo.
600     *
601     * It is a wrapper of the constructor.
602     *
603     * @param locale    the locale of this date interval formatter.
604     * @param dtitvinf  the DateIntervalInfo object to be adopted.
605     * @param skeleton  the skeleton of this formatter.
606     * @param status    Output param set to success/failure code.
607     * @return          a date time interval formatter which the caller owns.
608     * @internal ICU 4.0
609     */
610    static DateIntervalFormat* U_EXPORT2 create(const Locale& locale,
611                                                DateIntervalInfo* dtitvinf,
612                                                const UnicodeString* skeleton,
613                                                UErrorCode& status);
614
615    /**
616     * Create a simple date/time formatter from skeleton, given locale,
617     * and date time pattern generator.
618     *
619     * @param skeleton  the skeleton on which date format based.
620     * @param locale    the given locale.
621     * @param dtpng     the date time pattern generator.
622     * @param status    Output param to be set to success/failure code.
623     *                  If it is failure, the returned date formatter will
624     *                  be NULL.
625     * @return          a simple date formatter which the caller owns.
626     * @internal ICU 4.0
627     */
628    static SimpleDateFormat* U_EXPORT2 createSDFPatternInstance(
629                                        const UnicodeString& skeleton,
630                                        const Locale& locale,
631                                        DateTimePatternGenerator* dtpng,
632                                        UErrorCode& status);
633
634
635    /**
636     *  Below are for generating interval patterns local to the formatter
637     */
638
639
640    /**
641     * Format 2 Calendars using fall-back interval pattern
642     *
643     * The full pattern used in this fall-back format is the
644     * full pattern of the date formatter.
645     *
646     * @param fromCalendar      calendar set to the from date in date interval
647     *                          to be formatted into date interval string
648     * @param toCalendar        calendar set to the to date in date interval
649     *                          to be formatted into date interval string
650     * @param appendTo          Output parameter to receive result.
651     *                          Result is appended to existing contents.
652     * @param pos               On input: an alignment field, if desired.
653     *                          On output: the offsets of the alignment field.
654     * @param status            output param set to success/failure code on exit
655     * @return                  Reference to 'appendTo' parameter.
656     * @internal ICU 4.0
657     */
658    UnicodeString& fallbackFormat(Calendar& fromCalendar,
659                                  Calendar& toCalendar,
660                                  UnicodeString& appendTo,
661                                  FieldPosition& pos,
662                                  UErrorCode& status) const;
663
664
665
666    /**
667     * Initialize interval patterns locale to this formatter
668     *
669     * This code is a bit complicated since
670     * 1. the interval patterns saved in resource bundle files are interval
671     *    patterns based on date or time only.
672     *    It does not have interval patterns based on both date and time.
673     *    Interval patterns on both date and time are algorithm generated.
674     *
675     *    For example, it has interval patterns on skeleton "dMy" and "hm",
676     *    but it does not have interval patterns on skeleton "dMyhm".
677     *
678     *    The rule to generate interval patterns for both date and time skeleton are
679     *    1) when the year, month, or day differs, concatenate the two original
680     *    expressions with a separator between,
681     *    For example, interval pattern from "Jan 10, 2007 10:10 am"
682     *    to "Jan 11, 2007 10:10am" is
683     *    "Jan 10, 2007 10:10 am - Jan 11, 2007 10:10am"
684     *
685     *    2) otherwise, present the date followed by the range expression
686     *    for the time.
687     *    For example, interval pattern from "Jan 10, 2007 10:10 am"
688     *    to "Jan 10, 2007 11:10am" is
689     *    "Jan 10, 2007 10:10 am - 11:10am"
690     *
691     * 2. even a pattern does not request a certain calendar field,
692     *    the interval pattern needs to include such field if such fields are
693     *    different between 2 dates.
694     *    For example, a pattern/skeleton is "hm", but the interval pattern
695     *    includes year, month, and date when year, month, and date differs.
696     *
697     *
698     * @param status    output param set to success/failure code on exit
699     * @internal ICU 4.0
700     */
701    void initializePattern(UErrorCode& status);
702
703
704
705    /**
706     * Set fall back interval pattern given a calendar field,
707     * a skeleton, and a date time pattern generator.
708     * @param field      the largest different calendar field
709     * @param skeleton   a skeleton
710     * @param status     output param set to success/failure code on exit
711     * @internal ICU 4.0
712     */
713    void setFallbackPattern(UCalendarDateFields field,
714                            const UnicodeString& skeleton,
715                            UErrorCode& status);
716
717
718
719    /**
720     * get separated date and time skeleton from a combined skeleton.
721     *
722     * The difference between date skeleton and normalizedDateSkeleton are:
723     * 1. both 'y' and 'd' are appeared only once in normalizeDateSkeleton
724     * 2. 'E' and 'EE' are normalized into 'EEE'
725     * 3. 'MM' is normalized into 'M'
726     *
727     ** the difference between time skeleton and normalizedTimeSkeleton are:
728     * 1. both 'H' and 'h' are normalized as 'h' in normalized time skeleton,
729     * 2. 'a' is omitted in normalized time skeleton.
730     * 3. there is only one appearance for 'h', 'm','v', 'z' in normalized time
731     *    skeleton
732     *
733     *
734     *  @param skeleton               given combined skeleton.
735     *  @param date                   Output parameter for date only skeleton.
736     *  @param normalizedDate         Output parameter for normalized date only
737     *
738     *  @param time                   Output parameter for time only skeleton.
739     *  @param normalizedTime         Output parameter for normalized time only
740     *                                skeleton.
741     *
742     * @internal ICU 4.0
743     */
744    static void  U_EXPORT2 getDateTimeSkeleton(const UnicodeString& skeleton,
745                                    UnicodeString& date,
746                                    UnicodeString& normalizedDate,
747                                    UnicodeString& time,
748                                    UnicodeString& normalizedTime);
749
750
751
752    /**
753     * Generate date or time interval pattern from resource,
754     * and set them into the interval pattern locale to this formatter.
755     *
756     * It needs to handle the following:
757     * 1. need to adjust field width.
758     *    For example, the interval patterns saved in DateIntervalInfo
759     *    includes "dMMMy", but not "dMMMMy".
760     *    Need to get interval patterns for dMMMMy from dMMMy.
761     *    Another example, the interval patterns saved in DateIntervalInfo
762     *    includes "hmv", but not "hmz".
763     *    Need to get interval patterns for "hmz' from 'hmv'
764     *
765     * 2. there might be no pattern for 'y' differ for skeleton "Md",
766     *    in order to get interval patterns for 'y' differ,
767     *    need to look for it from skeleton 'yMd'
768     *
769     * @param dateSkeleton   normalized date skeleton
770     * @param timeSkeleton   normalized time skeleton
771     * @return               whether the resource is found for the skeleton.
772     *                       TRUE if interval pattern found for the skeleton,
773     *                       FALSE otherwise.
774     * @internal ICU 4.0
775     */
776    UBool setSeparateDateTimePtn(const UnicodeString& dateSkeleton,
777                                 const UnicodeString& timeSkeleton);
778
779
780
781
782    /**
783     * Generate interval pattern from existing resource
784     *
785     * It not only save the interval patterns,
786     * but also return the extended skeleton and its best match skeleton.
787     *
788     * @param field           largest different calendar field
789     * @param skeleton        skeleton
790     * @param bestSkeleton    the best match skeleton which has interval pattern
791     *                        defined in resource
792     * @param differenceInfo  the difference between skeleton and best skeleton
793     *         0 means the best matched skeleton is the same as input skeleton
794     *         1 means the fields are the same, but field width are different
795     *         2 means the only difference between fields are v/z,
796     *        -1 means there are other fields difference
797     *
798     * @param extendedSkeleton      extended skeleton
799     * @param extendedBestSkeleton  extended best match skeleton
800     * @return                      whether the interval pattern is found
801     *                              through extending skeleton or not.
802     *                              TRUE if interval pattern is found by
803     *                              extending skeleton, FALSE otherwise.
804     * @internal ICU 4.0
805     */
806    UBool setIntervalPattern(UCalendarDateFields field,
807                             const UnicodeString* skeleton,
808                             const UnicodeString* bestSkeleton,
809                             int8_t differenceInfo,
810                             UnicodeString* extendedSkeleton = NULL,
811                             UnicodeString* extendedBestSkeleton = NULL);
812
813    /**
814     * Adjust field width in best match interval pattern to match
815     * the field width in input skeleton.
816     *
817     * TODO (xji) make a general solution
818     * The adjusting rule can be:
819     * 1. always adjust
820     * 2. never adjust
821     * 3. default adjust, which means adjust according to the following rules
822     * 3.1 always adjust string, such as MMM and MMMM
823     * 3.2 never adjust between string and numeric, such as MM and MMM
824     * 3.3 always adjust year
825     * 3.4 do not adjust 'd', 'h', or 'm' if h presents
826     * 3.5 do not adjust 'M' if it is numeric(?)
827     *
828     * Since date interval format is well-formed format,
829     * date and time skeletons are normalized previously,
830     * till this stage, the adjust here is only "adjust strings, such as MMM
831     * and MMMM, EEE and EEEE.
832     *
833     * @param inputSkeleton            the input skeleton
834     * @param bestMatchSkeleton        the best match skeleton
835     * @param bestMatchIntervalpattern the best match interval pattern
836     * @param differenceInfo           the difference between 2 skeletons
837     *                                 1 means only field width differs
838     *                                 2 means v/z exchange
839     * @param adjustedIntervalPattern  adjusted interval pattern
840     * @internal ICU 4.0
841     */
842    static void U_EXPORT2 adjustFieldWidth(
843                            const UnicodeString& inputSkeleton,
844                            const UnicodeString& bestMatchSkeleton,
845                            const UnicodeString& bestMatchIntervalPattern,
846                            int8_t differenceInfo,
847                            UnicodeString& adjustedIntervalPattern);
848
849    /**
850     * Concat a single date pattern with a time interval pattern,
851     * set it into the intervalPatterns, while field is time field.
852     * This is used to handle time interval patterns on skeleton with
853     * both time and date. Present the date followed by
854     * the range expression for the time.
855     * @param format         date and time format
856     * @param formatLen      format string length
857     * @param datePattern    date pattern
858     * @param field          time calendar field: AM_PM, HOUR, MINUTE
859     * @param status         output param set to success/failure code on exit
860     * @internal ICU 4.0
861     */
862    void concatSingleDate2TimeInterval(const UChar* format,
863                                       int32_t formatLen,
864                                       const UnicodeString& datePattern,
865                                       UCalendarDateFields field,
866                                       UErrorCode& status);
867
868    /**
869     * check whether a calendar field present in a skeleton.
870     * @param field      calendar field need to check
871     * @param skeleton   given skeleton on which to check the calendar field
872     * @return           true if field present in a skeleton.
873     * @internal ICU 4.0
874     */
875    static UBool U_EXPORT2 fieldExistsInSkeleton(UCalendarDateFields field,
876                                                 const UnicodeString& skeleton);
877
878
879    /**
880     * Split interval patterns into 2 part.
881     * @param intervalPattern  interval pattern
882     * @return the index in interval pattern which split the pattern into 2 part
883     * @internal ICU 4.0
884     */
885    static int32_t  U_EXPORT2 splitPatternInto2Part(const UnicodeString& intervalPattern);
886
887
888    /**
889     * Break interval patterns as 2 part and save them into pattern info.
890     * @param field            calendar field
891     * @param intervalPattern  interval pattern
892     * @internal ICU 4.0
893     */
894    void setIntervalPattern(UCalendarDateFields field,
895                            const UnicodeString& intervalPattern);
896
897
898    /**
899     * Break interval patterns as 2 part and save them into pattern info.
900     * @param field            calendar field
901     * @param intervalPattern  interval pattern
902     * @param laterDateFirst   whether later date appear first in interval pattern
903     * @internal ICU 4.0
904     */
905    void setIntervalPattern(UCalendarDateFields field,
906                            const UnicodeString& intervalPattern,
907                            UBool laterDateFirst);
908
909
910    /**
911     * Set pattern information.
912     *
913     * @param field            calendar field
914     * @param firstPart        the first part in interval pattern
915     * @param secondPart       the second part in interval pattern
916     * @param laterDateFirst   whether the first date in intervalPattern
917     *                         is earlier date or later date
918     * @internal ICU 4.0
919     */
920    void setPatternInfo(UCalendarDateFields field,
921                        const UnicodeString* firstPart,
922                        const UnicodeString* secondpart,
923                        UBool laterDateFirst);
924
925
926    // from calendar field to pattern letter
927    static const UChar fgCalendarFieldToPatternLetter[];
928
929
930    /**
931     * The interval patterns for this locale.
932     */
933    DateIntervalInfo*     fInfo;
934
935    /**
936     * The DateFormat object used to format single pattern
937     */
938    SimpleDateFormat*     fDateFormat;
939
940    /**
941     * The 2 calendars with the from and to date.
942     * could re-use the calendar in fDateFormat,
943     * but keeping 2 calendars make it clear and clean.
944     */
945    Calendar* fFromCalendar;
946    Calendar* fToCalendar;
947
948    /**
949     * Date time pattern generator
950     */
951    DateTimePatternGenerator* fDtpng;
952
953    /**
954     * Following are interval information relavent (locale) to this formatter.
955     */
956    UnicodeString fSkeleton;
957    PatternInfo fIntervalPatterns[DateIntervalInfo::kIPI_MAX_INDEX];
958};
959
960inline UBool
961DateIntervalFormat::operator!=(const Format& other) const  {
962    return !operator==(other);
963}
964
965U_NAMESPACE_END
966
967#endif /* #if !UCONFIG_NO_FORMATTING */
968
969#endif // _DTITVFMT_H__
970//eof
971