Add LayoutLocale class

third_party/WebKit/Source/platform/LayoutLocale.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/LayoutLocale.h"
+
+#include "platform/Language.h"
+#include "platform/text/LocaleToScriptMapping.h"
+#include "wtf/HashMap.h"
+#include "wtf/text/AtomicStringHash.h"
+#include "wtf/text/StringHash.h"
+
+#include <hb.h>
+
+namespace blink {
+
+const LayoutLocale* LayoutLocale::s_default = nullptr;
+
+static hb_language_t toHarfbuzLanguage(const AtomicString& locale)
+{
+    CString localeAsLatin1 = locale.latin1();
+    return hb_language_from_string(localeAsLatin1.data(), localeAsLatin1.length());
+}
+
+// SkFontMgr requires script-based locale names, like "zh-Hant" and "zh-Hans",
+// instead of "zh-CN" and "zh-TW".
+static CString toSkFontMgrLocale(const String& locale)
+{
+    if (!locale.startsWith("zh", TextCaseInsensitive))
+        return locale.ascii();
+
+    switch (localeToScriptCodeForFontSelection(locale)) {
+    case USCRIPT_SIMPLIFIED_HAN:
+        return "zh-Hans";
+    case USCRIPT_TRADITIONAL_HAN:
+        return "zh-Hant";
+    default:
+        return locale.ascii();
+    }
+}
+
+const CString& LayoutLocale::localeForSkFontMgr() const
+{
+    if (m_stringForSkFontMgr.isNull())
+        m_stringForSkFontMgr = toSkFontMgrLocale(m_string);
+    return m_stringForSkFontMgr;
+}
+
+UScriptCode LayoutLocale::scriptForHan() const
+{
+    if (m_scriptForHan != USCRIPT_COMMON)
+        return m_scriptForHan;
+
+    m_scriptForHan = scriptCodeForHanFromLocale(script(), localeString());
+    if (m_scriptForHan == USCRIPT_COMMON)
+        m_scriptForHan = USCRIPT_HAN;
+    return m_scriptForHan;
+}
+
+LayoutLocale::LayoutLocale(const AtomicString& locale)
+    : m_string(locale)
+    , m_harfbuzzLanguage(toHarfbuzLanguage(locale))
+    , m_script(localeToScriptCodeForFontSelection(locale))
+    , m_scriptForHan(USCRIPT_COMMON)
+    , m_hyphenationComputed(false)
+{
+}
+
+using LayoutLocaleMap = HashMap<AtomicString, RefPtr<LayoutLocale>, CaseFoldingHash>;
+
+static LayoutLocaleMap& getLocaleMap()
+{
+    DEFINE_STATIC_LOCAL(LayoutLocaleMap, localeMap, ());
+    return localeMap;
+}
+
+const LayoutLocale* LayoutLocale::get(const AtomicString& locale)
+{
+    if (locale.isNull())
+        return nullptr;
+
+    auto result = getLocaleMap().add(locale, nullptr);
+    if (result.isNewEntry)
+        result.storedValue->value = adoptRef(new LayoutLocale(locale));
+    return result.storedValue->value.get();
+}
+
+static const LayoutLocale* computeDefaultLocale()
+{
+    AtomicString locale = defaultLanguage();
+    if (!locale.isEmpty())
+        return LayoutLocale::get(locale);
+    return LayoutLocale::get("en");
+}
+
+const LayoutLocale& LayoutLocale::getDefault()
+{
+    if (!s_default)
+        s_default = computeDefaultLocale();
+    return *s_default;
+}
+
+void LayoutLocale::clearForTesting()
+{
+    s_default = nullptr;
+    getLocaleMap().clear();
+}
+
+Hyphenation* LayoutLocale::getHyphenation() const
+{
+    if (m_hyphenationComputed)
+        return m_hyphenation.get();
+
+    m_hyphenationComputed = true;
+    m_hyphenation = Hyphenation::platformGetHyphenation(localeString());
+    return m_hyphenation.get();
+}
+
+void LayoutLocale::setHyphenationForTesting(const AtomicString& localeString, PassRefPtr<Hyphenation> hyphenation)
+{
+    const LayoutLocale& locale = valueOrDefault(get(localeString));
+    locale.m_hyphenationComputed = true;
+    locale.m_hyphenation = hyphenation;
+}
+
+} // namespace blink