time_formatting.cc revision 5821806d5e7f356e8fa4b058a389a808ea183019 
1// Copyright (c) 2011 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "base/i18n/time_formatting.h"
6
7#include "base/logging.h"
8#include "base/memory/scoped_ptr.h"
9#include "base/utf_string_conversions.h"
10#include "base/time.h"
11#include "unicode/datefmt.h"
12#include "unicode/dtptngen.h"
13#include "unicode/smpdtfmt.h"
14
15using base::Time;
16
17namespace {
18
19string16 TimeFormat(const icu::DateFormat* formatter,
20                    const Time& time) {
21  DCHECK(formatter);
22  icu::UnicodeString date_string;
23
24  formatter->format(static_cast<UDate>(time.ToDoubleT() * 1000), date_string);
25  return string16(date_string.getBuffer(),
26                  static_cast<size_t>(date_string.length()));
27}
28
29string16 TimeFormatWithoutAmPm(const icu::DateFormat* formatter,
30                               const Time& time) {
31  DCHECK(formatter);
32  icu::UnicodeString time_string;
33
34  icu::FieldPosition ampm_field(icu::DateFormat::kAmPmField);
35  formatter->format(
36      static_cast<UDate>(time.ToDoubleT() * 1000), time_string, ampm_field);
37  int ampm_length = ampm_field.getEndIndex() - ampm_field.getBeginIndex();
38  if (ampm_length) {
39    int begin = ampm_field.getBeginIndex();
40    // Doesn't include any spacing before the field.
41    if (begin)
42      begin--;
43    time_string.removeBetween(begin, ampm_field.getEndIndex());
44  }
45  return string16(time_string.getBuffer(),
46                  static_cast<size_t>(time_string.length()));
47}
48
49}  // namespace
50
51namespace base {
52
53string16 TimeFormatTimeOfDay(const Time& time) {
54  // We can omit the locale parameter because the default should match
55  // Chrome's application locale.
56  scoped_ptr<icu::DateFormat> formatter(
57      icu::DateFormat::createTimeInstance(icu::DateFormat::kShort));
58  return TimeFormat(formatter.get(), time);
59}
60
61string16 TimeFormatTimeOfDayWithHourClockType(const Time& time,
62                                              HourClockType type,
63                                              AmPmClockType ampm) {
64  // Just redirect to the normal function if the default type matches the
65  // given type.
66  HourClockType default_type = GetHourClockType();
67  if (default_type == type && (type == k24HourClock || ampm == kKeepAmPm)) {
68    return TimeFormatTimeOfDay(time);
69  }
70
71  // Generate a locale-dependent format pattern. The generator will take
72  // care of locale-dependent formatting issues like which separator to
73  // use (some locales use '.' instead of ':'), and where to put the am/pm
74  // marker.
75  UErrorCode status = U_ZERO_ERROR;
76  scoped_ptr<icu::DateTimePatternGenerator> generator(
77      icu::DateTimePatternGenerator::createInstance(status));
78  DCHECK(U_SUCCESS(status));
79  const char* base_pattern = (type == k12HourClock ? "ahm" : "Hm");
80  icu::UnicodeString generated_pattern =
81      generator->getBestPattern(icu::UnicodeString(base_pattern), status);
82  DCHECK(U_SUCCESS(status));
83
84  // Then, format the time using the generated pattern.
85  icu::SimpleDateFormat formatter(generated_pattern, status);
86  DCHECK(U_SUCCESS(status));
87  if (ampm == kKeepAmPm) {
88    return TimeFormat(&formatter, time);
89  } else {
90    return TimeFormatWithoutAmPm(&formatter, time);
91  }
92}
93
94string16 TimeFormatShortDate(const Time& time) {
95  scoped_ptr<icu::DateFormat> formatter(
96      icu::DateFormat::createDateInstance(icu::DateFormat::kMedium));
97  return TimeFormat(formatter.get(), time);
98}
99
100string16 TimeFormatShortDateNumeric(const Time& time) {
101  scoped_ptr<icu::DateFormat> formatter(
102      icu::DateFormat::createDateInstance(icu::DateFormat::kShort));
103  return TimeFormat(formatter.get(), time);
104}
105
106string16 TimeFormatShortDateAndTime(const Time& time) {
107  scoped_ptr<icu::DateFormat> formatter(
108      icu::DateFormat::createDateTimeInstance(icu::DateFormat::kShort));
109  return TimeFormat(formatter.get(), time);
110}
111
112string16 TimeFormatFriendlyDateAndTime(const Time& time) {
113  scoped_ptr<icu::DateFormat> formatter(
114      icu::DateFormat::createDateTimeInstance(icu::DateFormat::kFull));
115  return TimeFormat(formatter.get(), time);
116}
117
118string16 TimeFormatFriendlyDate(const Time& time) {
119  scoped_ptr<icu::DateFormat> formatter(icu::DateFormat::createDateInstance(
120      icu::DateFormat::kFull));
121  return TimeFormat(formatter.get(), time);
122}
123
124HourClockType GetHourClockType() {
125  // TODO(satorux,jshin): Rework this with ures_getByKeyWithFallback()
126  // once it becomes public. The short time format can be found at
127  // "calendar/gregorian/DateTimePatterns/3" in the resources.
128  scoped_ptr<icu::SimpleDateFormat> formatter(
129      static_cast<icu::SimpleDateFormat*>(
130          icu::DateFormat::createTimeInstance(icu::DateFormat::kShort)));
131  // Retrieve the short time format.
132  icu::UnicodeString pattern_unicode;
133  formatter->toPattern(pattern_unicode);
134
135  // Determine what hour clock type the current locale uses, by checking
136  // "a" (am/pm marker) in the short time format. This is reliable as "a"
137  // is used by all of 12-hour clock formats, but not any of 24-hour clock
138  // formats, as shown below.
139  //
140  // % grep -A4 DateTimePatterns third_party/icu/source/data/locales/*.txt |
141  //   grep -B1 -- -- |grep -v -- '--' |
142  //   perl -nle 'print $1 if /^\S+\s+"(.*)"/' |sort -u
143  //
144  // H.mm
145  // H:mm
146  // HH.mm
147  // HH:mm
148  // a h:mm
149  // ah:mm
150  // ahh:mm
151  // h-mm a
152  // h:mm a
153  // hh:mm a
154  //
155  // See http://userguide.icu-project.org/formatparse/datetime for details
156  // about the date/time format syntax.
157  if (pattern_unicode.indexOf('a') == -1) {
158    return k24HourClock;
159  } else {
160    return k12HourClock;
161  }
162}
163
164}  // namespace base
165