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      1 /*
      2  * Copyright (C) 2010, 2013 Apple Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
     14  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
     15  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
     17  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     18  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     19  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     20  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     21  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     22  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
     23  * THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #include "config.h"
     27 #include "core/platform/Language.h"
     28 
     29 #include "wtf/HashMap.h"
     30 #include "wtf/RetainPtr.h"
     31 #include "wtf/text/WTFString.h"
     32 
     33 namespace WebCore {
     34 
     35 typedef HashMap<void*, LanguageChangeObserverFunction> ObserverMap;
     36 static ObserverMap& observerMap()
     37 {
     38     DEFINE_STATIC_LOCAL(ObserverMap, map, ());
     39     return map;
     40 }
     41 
     42 void addLanguageChangeObserver(void* context, LanguageChangeObserverFunction customObserver)
     43 {
     44     observerMap().set(context, customObserver);
     45 }
     46 
     47 void removeLanguageChangeObserver(void* context)
     48 {
     49     ASSERT(observerMap().contains(context));
     50     observerMap().remove(context);
     51 }
     52 
     53 void languageDidChange()
     54 {
     55     ObserverMap::iterator end = observerMap().end();
     56     for (ObserverMap::iterator iter = observerMap().begin(); iter != end; ++iter)
     57         iter->value(iter->key);
     58 }
     59 
     60 String defaultLanguage()
     61 {
     62     Vector<String> languages = userPreferredLanguages();
     63     if (languages.size())
     64         return languages[0];
     65 
     66     return emptyString();
     67 }
     68 
     69 static Vector<String>& preferredLanguagesOverride()
     70 {
     71     DEFINE_STATIC_LOCAL(Vector<String>, override, ());
     72     return override;
     73 }
     74 
     75 Vector<String> userPreferredLanguagesOverride()
     76 {
     77     return preferredLanguagesOverride();
     78 }
     79 
     80 void overrideUserPreferredLanguages(const Vector<String>& override)
     81 {
     82     preferredLanguagesOverride() = override;
     83 }
     84 
     85 Vector<String> userPreferredLanguages()
     86 {
     87     Vector<String>& override = preferredLanguagesOverride();
     88     if (!override.isEmpty())
     89         return override;
     90 
     91     return platformUserPreferredLanguages();
     92 }
     93 
     94 static String canonicalLanguageIdentifier(const String& languageCode)
     95 {
     96     String lowercaseLanguageCode = languageCode.lower();
     97 
     98     if (lowercaseLanguageCode.length() >= 3 && lowercaseLanguageCode[2] == '_')
     99         lowercaseLanguageCode.replace(2, 1, "-");
    100 
    101     return lowercaseLanguageCode;
    102 }
    103 
    104 size_t indexOfBestMatchingLanguageInList(const String& language, const Vector<String>& languageList)
    105 {
    106     String languageWithoutLocaleMatch;
    107     String languageMatchButNotLocale;
    108     size_t languageWithoutLocaleMatchIndex = 0;
    109     size_t languageMatchButNotLocaleMatchIndex = 0;
    110     bool canMatchLanguageOnly = (language.length() == 2 || (language.length() >= 3 && language[2] == '-'));
    111 
    112     for (size_t i = 0; i < languageList.size(); ++i) {
    113         String canonicalizedLanguageFromList = canonicalLanguageIdentifier(languageList[i]);
    114 
    115         if (language == canonicalizedLanguageFromList)
    116             return i;
    117 
    118         if (canMatchLanguageOnly && canonicalizedLanguageFromList.length() >= 2) {
    119             if (language[0] == canonicalizedLanguageFromList[0] && language[1] == canonicalizedLanguageFromList[1]) {
    120                 if (!languageWithoutLocaleMatch.length() && canonicalizedLanguageFromList.length() == 2) {
    121                     languageWithoutLocaleMatch = languageList[i];
    122                     languageWithoutLocaleMatchIndex = i;
    123                 }
    124                 if (!languageMatchButNotLocale.length() && canonicalizedLanguageFromList.length() >= 3) {
    125                     languageMatchButNotLocale = languageList[i];
    126                     languageMatchButNotLocaleMatchIndex = i;
    127                 }
    128             }
    129         }
    130     }
    131 
    132     // If we have both a language-only match and a languge-but-not-locale match, return the
    133     // languge-only match as is considered a "better" match. For example, if the list
    134     // provided has both "en-GB" and "en" and the user prefers "en-US" we will return "en".
    135     if (languageWithoutLocaleMatch.length())
    136         return languageWithoutLocaleMatchIndex;
    137 
    138     if (languageMatchButNotLocale.length())
    139         return languageMatchButNotLocaleMatchIndex;
    140 
    141     return languageList.size();
    142 }
    143 
    144 }
    145