base/i18n/time_formatting.cc

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