time_formatting.cc revision ddb351dbec246cf1fab5ec20d2d5520909041de1 
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
29}  // namespace
30
31namespace base {
32
33string16 TimeFormatTimeOfDay(const Time& time) {
34  // We can omit the locale parameter because the default should match
35  // Chrome's application locale.
36  scoped_ptr<icu::DateFormat> formatter(
37      icu::DateFormat::createTimeInstance(icu::DateFormat::kShort));
38  return TimeFormat(formatter.get(), time);
39}
40
41string16 TimeFormatTimeOfDayWithHourClockType(const Time& time,
42                                              HourClockType type) {
43  // Just redirect to the normal function if the default type matches the
44  // given type.
45  HourClockType default_type = GetHourClockType();
46  if (default_type == type) {
47    return TimeFormatTimeOfDay(time);
48  }
49
50  // Generate a locale-dependent format pattern. The generator will take
51  // care of locale-dependent formatting issues like which separator to
52  // use (some locales use '.' instead of ':'), and where to put the am/pm
53  // marker.
54  UErrorCode status = U_ZERO_ERROR;
55  icu::DateTimePatternGenerator *generator =
56      icu::DateTimePatternGenerator::createInstance(status);
57  CHECK(U_SUCCESS(status));
58  const char* base_pattern = (type == k12HourClock ? "ahm" : "Hm");
59  icu::UnicodeString generated_pattern =
60      generator->getBestPattern(icu::UnicodeString(base_pattern), status);
61  CHECK(U_SUCCESS(status));
62
63  // Then, format the time using the generated pattern.
64  icu::SimpleDateFormat formatter(generated_pattern, status);
65  CHECK(U_SUCCESS(status));
66  return TimeFormat(&formatter, time);
67}
68
69string16 TimeFormatShortDate(const Time& time) {
70  scoped_ptr<icu::DateFormat> formatter(
71      icu::DateFormat::createDateInstance(icu::DateFormat::kMedium));
72  return TimeFormat(formatter.get(), time);
73}
74
75string16 TimeFormatShortDateNumeric(const Time& time) {
76  scoped_ptr<icu::DateFormat> formatter(
77      icu::DateFormat::createDateInstance(icu::DateFormat::kShort));
78  return TimeFormat(formatter.get(), time);
79}
80
81string16 TimeFormatShortDateAndTime(const Time& time) {
82  scoped_ptr<icu::DateFormat> formatter(
83      icu::DateFormat::createDateTimeInstance(icu::DateFormat::kShort));
84  return TimeFormat(formatter.get(), time);
85}
86
87string16 TimeFormatFriendlyDateAndTime(const Time& time) {
88  scoped_ptr<icu::DateFormat> formatter(
89      icu::DateFormat::createDateTimeInstance(icu::DateFormat::kFull));
90  return TimeFormat(formatter.get(), time);
91}
92
93string16 TimeFormatFriendlyDate(const Time& time) {
94  scoped_ptr<icu::DateFormat> formatter(icu::DateFormat::createDateInstance(
95      icu::DateFormat::kFull));
96  return TimeFormat(formatter.get(), time);
97}
98
99HourClockType GetHourClockType() {
100  // TODO(satorux,jshin): Rework this with ures_getByKeyWithFallback()
101  // once it becomes public. The short time format can be found at
102  // "calendar/gregorian/DateTimePatterns/3" in the resources.
103  scoped_ptr<icu::SimpleDateFormat> formatter(
104      static_cast<icu::SimpleDateFormat*>(
105          icu::DateFormat::createTimeInstance(icu::DateFormat::kShort)));
106  // Retrieve the short time format.
107  icu::UnicodeString pattern_unicode;
108  formatter->toPattern(pattern_unicode);
109
110  // Determine what hour clock type the current locale uses, by checking
111  // "a" (am/pm marker) in the short time format. This is reliable as "a"
112  // is used by all of 12-hour clock formats, but not any of 24-hour clock
113  // formats, as shown below.
114  //
115  // % grep -A4 DateTimePatterns third_party/icu/source/data/locales/*.txt |
116  //   grep -B1 -- -- |grep -v -- '--' |
117  //   perl -nle 'print $1 if /^\S+\s+"(.*)"/' |sort -u
118  //
119  // H.mm
120  // H:mm
121  // HH.mm
122  // HH:mm
123  // a h:mm
124  // ah:mm
125  // ahh:mm
126  // h-mm a
127  // h:mm a
128  // hh:mm a
129  //
130  // See http://userguide.icu-project.org/formatparse/datetime for details
131  // about the date/time format syntax.
132  if (pattern_unicode.indexOf('a') == -1) {
133    return k24HourClock;
134  } else {
135    return k12HourClock;
136  }
137}
138
139}  // namespace base
140