Source/platform/fonts/android/FontCacheAndroid.cpp

/*
 * Copyright (c) 2011 Google Inc. All rights reserved.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#include "config.h"
#include "platform/fonts/FontCache.h"

#include "platform/Language.h"
#include "platform/fonts/SimpleFontData.h"
#include "platform/fonts/FontDescription.h"
#include "platform/fonts/FontFaceCreationParams.h"
#include "third_party/skia/include/core/SkTypeface.h"
#include "third_party/skia/include/ports/SkFontMgr.h"

namespace blink {

static AtomicString getFamilyNameForCharacter(UChar32 c, const FontDescription& fontDescription)
{
    RefPtr<SkFontMgr> fm = adoptRef(SkFontMgr::RefDefault());
    RefPtr<SkTypeface> typeface = adoptRef(fm->matchFamilyStyleCharacter(0, SkFontStyle(), fontDescription.locale().isEmpty() ? defaultLanguage().ascii().data() : fontDescription.locale().ascii().data(), c));
    if (!typeface)
        return emptyAtom;

    SkString skiaFamilyName;
    typeface->getFamilyName(&skiaFamilyName);
    return skiaFamilyName.c_str();
}

PassRefPtr<SimpleFontData> FontCache::fallbackFontForCharacter(const FontDescription& fontDescription, UChar32 c, const SimpleFontData*)
{
    AtomicString familyName = getFamilyNameForCharacter(c, fontDescription);
    if (familyName.isEmpty())
        return getLastResortFallbackFont(fontDescription, DoNotRetain);
    return fontDataFromFontPlatformData(getFontPlatformData(fontDescription, FontFaceCreationParams(familyName)), DoNotRetain);
}

// static
AtomicString FontCache::getGenericFamilyNameForScript(const AtomicString& familyName, const FontDescription& fontDescription)
{
    // This is a hack to use the preferred font for CJK scripts.
    // FIXME: Use new Skia API once Android system supports per-family and per-script fallback fonts.
    UChar32 examplerChar;
    switch (fontDescription.script()) {
    case USCRIPT_SIMPLIFIED_HAN:
    case USCRIPT_TRADITIONAL_HAN:
    case USCRIPT_KATAKANA_OR_HIRAGANA:
        examplerChar = 0x4E00; // A common character in Japanese and Chinese.
        break;
    case USCRIPT_HANGUL:
        examplerChar = 0xAC00;
        break;
    default:
        // For other scripts, use the default generic family mapping logic.
        return familyName;
    }

    return getFamilyNameForCharacter(examplerChar, fontDescription);
}

} // namespace blink