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27 #include "platform/Language.h"
29 #include "public/platform/Platform.h"
30 #include "wtf/text/WTFString.h"
34 static const AtomicString& platformLanguage()
36 DEFINE_STATIC_LOCAL(AtomicString, computedDefaultLanguage, ());
37 if (computedDefaultLanguage.isEmpty()) {
38 computedDefaultLanguage = blink::Platform::current()->defaultLocale();
39 ASSERT(!computedDefaultLanguage.isEmpty());
41 return computedDefaultLanguage;
44 AtomicString defaultLanguage()
46 Vector<AtomicString> languages = userPreferredLanguages();
47 if (!languages.isEmpty())
53 static Vector<AtomicString>& preferredLanguagesOverride()
55 DEFINE_STATIC_LOCAL(Vector<AtomicString>, override, ());
59 Vector<AtomicString> userPreferredLanguagesOverride()
61 return preferredLanguagesOverride();
64 void overrideUserPreferredLanguages(const Vector<AtomicString>& override)
66 preferredLanguagesOverride() = override;
69 Vector<AtomicString> userPreferredLanguages()
71 Vector<AtomicString>& override = preferredLanguagesOverride();
72 if (!override.isEmpty())
75 Vector<AtomicString> languages;
76 languages.reserveInitialCapacity(1);
77 languages.append(platformLanguage());
81 static String canonicalLanguageIdentifier(const String& languageCode)
83 String lowercaseLanguageCode = languageCode.lower();
85 if (lowercaseLanguageCode.length() >= 3 && lowercaseLanguageCode[2] == '_')
86 lowercaseLanguageCode.replace(2, 1, "-");
88 return lowercaseLanguageCode;
91 size_t indexOfBestMatchingLanguageInList(const AtomicString& language, const Vector<AtomicString>& languageList)
93 AtomicString languageWithoutLocaleMatch;
94 AtomicString languageMatchButNotLocale;
95 size_t languageWithoutLocaleMatchIndex = 0;
96 size_t languageMatchButNotLocaleMatchIndex = 0;
97 bool canMatchLanguageOnly = (language.length() == 2 || (language.length() >= 3 && language[2] == '-'));
99 for (size_t i = 0; i < languageList.size(); ++i) {
100 String canonicalizedLanguageFromList = canonicalLanguageIdentifier(languageList[i]);
102 if (language == canonicalizedLanguageFromList)
105 if (canMatchLanguageOnly && canonicalizedLanguageFromList.length() >= 2) {
106 if (language[0] == canonicalizedLanguageFromList[0] && language[1] == canonicalizedLanguageFromList[1]) {
107 if (!languageWithoutLocaleMatch.length() && canonicalizedLanguageFromList.length() == 2) {
108 languageWithoutLocaleMatch = languageList[i];
109 languageWithoutLocaleMatchIndex = i;
111 if (!languageMatchButNotLocale.length() && canonicalizedLanguageFromList.length() >= 3) {
112 languageMatchButNotLocale = languageList[i];
113 languageMatchButNotLocaleMatchIndex = i;
119 // If we have both a language-only match and a languge-but-not-locale match, return the
120 // languge-only match as is considered a "better" match. For example, if the list
121 // provided has both "en-GB" and "en" and the user prefers "en-US" we will return "en".
122 if (languageWithoutLocaleMatch.length())
123 return languageWithoutLocaleMatchIndex;
125 if (languageMatchButNotLocale.length())
126 return languageMatchButNotLocaleMatchIndex;
128 return languageList.size();