chrome/browser/chromeos/system/timezone_util.cc

   1 // Copyright 2013 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 "chrome/browser/chromeos/system/timezone_util.h"
   6
   7 #include <string>
   8
   9 #include "base/i18n/rtl.h"
  10 #include "base/lazy_instance.h"
  11 #include "base/strings/string_util.h"
  12 #include "base/strings/stringprintf.h"
  13 #include "base/strings/utf_string_conversions.h"
  14 #include "base/synchronization/lock.h"
  15 #include "base/values.h"
  16 #include "chromeos/settings/timezone_settings.h"
  17 #include "grit/generated_resources.h"
  18 #include "third_party/icu/source/common/unicode/ures.h"
  19 #include "third_party/icu/source/common/unicode/utypes.h"
  20 #include "third_party/icu/source/i18n/unicode/calendar.h"
  21 #include "third_party/icu/source/i18n/unicode/timezone.h"
  22 #include "ui/base/l10n/l10n_util.h"
  23
  24 namespace {
  25
  26 struct UResClose {
  27   inline void operator() (UResourceBundle* b) const {
  28     ures_close(b);
  29   }
  30 };
  31
  32 static base::LazyInstance<base::Lock>::Leaky
  33     g_timezone_bundle_lock = LAZY_INSTANCE_INITIALIZER;
  34
  35 // Returns an exemplary city in the given timezone.
  36 base::string16 GetExemplarCity(const icu::TimeZone& zone) {
  37   // TODO(jungshik): After upgrading to ICU 4.6, use U_ICUDATA_ZONE
  38   static const char* zone_bundle_name = NULL;
  39
  40   // These will be leaked at the end.
  41   static UResourceBundle *zone_bundle = NULL;
  42   static UResourceBundle *zone_strings = NULL;
  43
  44   UErrorCode status = U_ZERO_ERROR;
  45   {
  46     base::AutoLock lock(g_timezone_bundle_lock.Get());
  47     if (zone_bundle == NULL)
  48       zone_bundle = ures_open(zone_bundle_name, uloc_getDefault(), &status);
  49
  50     if (zone_strings == NULL)
  51       zone_strings = ures_getByKey(zone_bundle, "zone_strings", NULL, &status);
  52   }
  53
  54   icu::UnicodeString zone_id;
  55   zone.getID(zone_id);
  56   std::string zone_id_str;
  57   zone_id.toUTF8String(zone_id_str);
  58
  59   // Resource keys for timezones use ':' in place of '/'.
  60   ReplaceSubstringsAfterOffset(&zone_id_str, 0, "/", ":");
  61   scoped_ptr<UResourceBundle, UResClose> zone_item(
  62       ures_getByKey(zone_strings, zone_id_str.c_str(), NULL, &status));
  63   icu::UnicodeString city;
  64   if (!U_FAILURE(status)) {
  65     city = icu::ures_getUnicodeStringByKey(zone_item.get(), "ec", &status);
  66     if (U_SUCCESS(status))
  67       return base::string16(city.getBuffer(), city.length());
  68   }
  69
  70   // Fallback case in case of failure.
  71   ReplaceSubstringsAfterOffset(&zone_id_str, 0, ":", "/");
  72   // Take the last component of a timezone id (e.g. 'Baz' in 'Foo/Bar/Baz').
  73   // Depending on timezones, keeping all but the 1st component
  74   // (e.g. Bar/Baz) may be better, but our current list does not have
  75   // any timezone for which that's the case.
  76   std::string::size_type slash_pos = zone_id_str.rfind('/');
  77   if (slash_pos != std::string::npos && slash_pos < zone_id_str.size())
  78     zone_id_str.erase(0, slash_pos + 1);
  79   // zone id has '_' in place of ' '.
  80   ReplaceSubstringsAfterOffset(&zone_id_str, 0, "_", " ");
  81   return base::ASCIIToUTF16(zone_id_str);
  82 }
  83
  84 // Gets the given timezone's name for visualization.
  85 base::string16 GetTimezoneName(const icu::TimeZone& timezone) {
  86   // Instead of using the raw_offset, use the offset in effect now.
  87   // For instance, US Pacific Time, the offset shown will be -7 in summer
  88   // while it'll be -8 in winter.
  89   int raw_offset, dst_offset;
  90   UDate now = icu::Calendar::getNow();
  91   UErrorCode status = U_ZERO_ERROR;
  92   timezone.getOffset(now, false, raw_offset, dst_offset, status);
  93   DCHECK(U_SUCCESS(status));
  94   int offset = raw_offset + dst_offset;
  95   // |offset| is in msec.
  96   int minute_offset = std::abs(offset) / 60000;
  97   int hour_offset = minute_offset / 60;
  98   int min_remainder = minute_offset % 60;
  99   // Some timezones have a non-integral hour offset. So, we need to use hh:mm
 100   // form.
 101   std::string  offset_str = base::StringPrintf(offset >= 0 ?
 102       "UTC+%d:%02d" : "UTC-%d:%02d", hour_offset, min_remainder);
 103
 104   // TODO(jungshik): When coming up with a better list of timezones, we also
 105   // have to come up with better 'display' names. One possibility is to list
 106   // multiple cities (e.g. "Los Angeles, Vancouver .." in the order of
 107   // the population of a country the city belongs to.).
 108   // We can also think of using LONG_GENERIC or LOCATION once we upgrade
 109   // to ICU 4.6.
 110   // In the meantime, we use "LONG" name with "Exemplar City" to distinguish
 111   // multiple timezones with the same "LONG" name but with different
 112   // rules (e.g. US Mountain Time in Denver vs Phoenix).
 113   icu::UnicodeString name;
 114   timezone.getDisplayName(dst_offset != 0, icu::TimeZone::LONG, name);
 115   base::string16 result(l10n_util::GetStringFUTF16(
 116       IDS_OPTIONS_SETTINGS_TIMEZONE_DISPLAY_TEMPLATE,
 117       base::ASCIIToUTF16(offset_str),
 118       base::string16(name.getBuffer(), name.length()),
 119       GetExemplarCity(timezone)));
 120   base::i18n::AdjustStringForLocaleDirection(&result);
 121   return result;
 122 }
 123
 124 }  // namespace
 125
 126 namespace chromeos {
 127 namespace system {
 128
 129 // Creates a list of pairs of each timezone's ID and name.
 130 scoped_ptr<base::ListValue> GetTimezoneList() {
 131   const std::vector<icu::TimeZone*> &timezones =
 132       chromeos::system::TimezoneSettings::GetInstance()->GetTimezoneList();
 133   scoped_ptr<base::ListValue> timezoneList(new base::ListValue());
 134   for (std::vector<icu::TimeZone*>::const_iterator iter = timezones.begin();
 135        iter != timezones.end(); ++iter) {
 136     const icu::TimeZone* timezone = *iter;
 137     base::ListValue* option = new base::ListValue();
 138     option->Append(new base::StringValue(
 139         chromeos::system::TimezoneSettings::GetTimezoneID(*timezone)));
 140     option->Append(new base::StringValue(GetTimezoneName(*timezone)));
 141     timezoneList->Append(option);
 142   }
 143   return timezoneList.Pass();
 144 }
 145
 146 }  // namespace system
 147 }  // namespace chromeos