More LayoutLocale refactor with additional Chinese support

third_party/WebKit/Source/platform/fonts/AcceptLanguagesResolver.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "platform/fonts/AcceptLanguagesResolver.h"
 
-#include "platform/Language.h"
-#include "platform/text/LocaleToScriptMapping.h"
-#include <unicode/locid.h>
+#include "platform/LayoutLocale.h"
 
 namespace blink {
 
-UScriptCode AcceptLanguagesResolver::m_preferredHanScript = USCRIPT_COMMON;
-const char* AcceptLanguagesResolver::m_preferredHanSkFontMgrLocale = nullptr;
-
-// SkFontMgr requires script-based locale names, like "zh-Hant" and "zh-Hans",
-// instead of "zh-CN" and "zh-TW".
-static const char* toSkFontMgrLocaleForHan(UScriptCode script)
-{
-    switch (script) {
-    case USCRIPT_KATAKANA_OR_HIRAGANA:
-        return "ja-jp";
-    case USCRIPT_HANGUL:
-        return "ko-kr";
-    case USCRIPT_SIMPLIFIED_HAN:
-        return "zh-Hans";
-    case USCRIPT_TRADITIONAL_HAN:
-        return "zh-Hant";
-    default:
-        ASSERT_NOT_REACHED();
-        return nullptr;
-    }
-}
-
 void AcceptLanguagesResolver::acceptLanguagesChanged(
     const String& acceptLanguages)
 {
-    // Use the UI locale if it can disambiguate the Unified Han.
-    // Historically we use ICU on Windows. crbug.com/586520
-#if OS(WIN)
-    // Since Chrome synchronizes the ICU default locale with its UI locale,
-    // this ICU locale tells the current UI locale of Chrome.
-    m_preferredHanScript = scriptCodeForHanFromLocale(
-        icu::Locale::getDefault().getName(), '_');
-#else
-    m_preferredHanScript = scriptCodeForHanFromLocale(defaultLanguage());
-#endif
-    if (m_preferredHanScript != USCRIPT_COMMON) {
-        // We don't need additional locale if defaultLanguage() can disambiguate
-        // since it's always passed to matchFamilyStyleCharacter() separately.
-        m_preferredHanSkFontMgrLocale = nullptr;
-        return;
-    }
-
-    updateFromAcceptLanguages(acceptLanguages);
+    LayoutLocale::setLocaleForHan(

[drott, 2016/07/28 08:05:23]

This line looks a bit surprising to me. Is this triggering an update on the
object returned from localeForHanFromAcceptLanguages?

[kojii, 2016/07/29 04:27:40]

No, the returned object is const. The pointer to the returned object is set to a
static variable in LayoutLocale (static const LayoutLocale* s_defaultForHan).

[drott, 2016/08/02 07:14:15]

Got it, thanks for the explanation. Now I see that this was in the
acceptLanguagesChanged() and I rememebered what we discussed for when we
introduced this callback from the host process. Makes sense.

+        localeForHanFromAcceptLanguages(acceptLanguages));
 }
 
-void AcceptLanguagesResolver::updateFromAcceptLanguages(
+const LayoutLocale* AcceptLanguagesResolver::localeForHanFromAcceptLanguages(
     const String& acceptLanguages)
 {
     // Use the first acceptLanguages that can disambiguate.
     Vector<String> languages;
     acceptLanguages.split(',', languages);
     for (String token : languages) {
         token = token.stripWhiteSpace();
-        m_preferredHanScript = scriptCodeForHanFromLocale(token);
-        if (m_preferredHanScript != USCRIPT_COMMON) {
-            m_preferredHanSkFontMgrLocale = toSkFontMgrLocaleForHan(
-                m_preferredHanScript);
-            return;
-        }
+        const LayoutLocale* locale = LayoutLocale::get(AtomicString(token));
+        if (locale->hasScriptForHan())
+            return locale;
     }
 
-    m_preferredHanScript = USCRIPT_COMMON;
-    m_preferredHanSkFontMgrLocale = nullptr;
+    return nullptr;
 }
 
 } // namespace blink