third_party/WebKit/Source/platform/fonts/skia/FontCacheSkia.cpp

/*
 * Copyright (c) 2006, 2007, 2008, 2009 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#include "SkFontMgr.h"
#include "SkStream.h"
#include "SkTypeface.h"
#include "platform/Language.h"
#include "platform/fonts/AcceptLanguagesResolver.h"
#include "platform/fonts/AlternateFontFamily.h"
#include "platform/fonts/FontCache.h"
#include "platform/fonts/FontDescription.h"
#include "platform/fonts/FontFaceCreationParams.h"
#include "platform/fonts/SimpleFontData.h"
#include "public/platform/Platform.h"
#include "public/platform/linux/WebSandboxSupport.h"
#include "wtf/Assertions.h"
#include "wtf/text/AtomicString.h"
#include "wtf/text/CString.h"
#include <unicode/locid.h>

#if !OS(WIN) && !OS(ANDROID)
#include "SkFontConfigInterface.h"

static PassRefPtr<SkTypeface> typefaceForFontconfigInterfaceIdAndTtcIndex(int fontconfigInterfaceId, int ttcIndex)
{
    SkAutoTUnref<SkFontConfigInterface> fci(SkFontConfigInterface::RefGlobal());
    SkFontConfigInterface::FontIdentity fontIdentity;
    fontIdentity.fID = fontconfigInterfaceId;
    fontIdentity.fTTCIndex = ttcIndex;
    return adoptRef(fci->createTypeface(fontIdentity));
}
#endif

namespace blink {

#if OS(ANDROID) || OS(LINUX)
// Android special locale for retrieving the color emoji font
// based on the proposed changes in UTR #51 for introducing
// an Emoji script code:
// http://www.unicode.org/reports/tr51/proposed.html#Emoji_Script
static const char* kAndroidColorEmojiLocale = "und-Zsye";

// This function is called on android or when we are emulating android fonts on linux and the
// embedder has overriden the default fontManager with WebFontRendering::setSkiaFontMgr.
// static
AtomicString FontCache::getFamilyNameForCharacter(SkFontMgr* fm, UChar32 c, const FontDescription& fontDescription, FontFallbackPriority fallbackPriority)
{
    ASSERT(fm);

    const size_t kMaxLocales = 4;
    const char* bcp47Locales[kMaxLocales];
    size_t localeCount = 0;

    if (fallbackPriority == FontFallbackPriority::EmojiEmoji) {
        bcp47Locales[localeCount++] = kAndroidColorEmojiLocale;
    }
    if (const char* hanLocale = AcceptLanguagesResolver::preferredHanSkFontMgrLocale())
        bcp47Locales[localeCount++] = hanLocale;
    CString defaultLocale = toSkFontMgrLocale(defaultLanguage());
    bcp47Locales[localeCount++] = defaultLocale.data();
    CString fontLocale;
    if (!fontDescription.locale().isEmpty()) {
        fontLocale = toSkFontMgrLocale(fontDescription.locale());
        bcp47Locales[localeCount++] = fontLocale.data();
    }
    ASSERT_WITH_SECURITY_IMPLICATION(localeCount < kMaxLocales);
    RefPtr<SkTypeface> typeface = adoptRef(fm->matchFamilyStyleCharacter(0, SkFontStyle(), bcp47Locales, localeCount, c));
    if (!typeface)
        return emptyAtom;

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

void FontCache::platformInit()
{
}

PassRefPtr<SimpleFontData> FontCache::fallbackOnStandardFontStyle(
    const FontDescription& fontDescription, UChar32 character)
{
    FontDescription substituteDescription(fontDescription);
    substituteDescription.setStyle(FontStyleNormal);
    substituteDescription.setWeight(FontWeightNormal);

    FontFaceCreationParams creationParams(substituteDescription.family().family());
    FontPlatformData* substitutePlatformData = getFontPlatformData(substituteDescription, creationParams);
    if (substitutePlatformData && substitutePlatformData->fontContainsCharacter(character)) {
        FontPlatformData platformData = FontPlatformData(*substitutePlatformData);
        platformData.setSyntheticBold(fontDescription.weight() >= FontWeight600);
        platformData.setSyntheticItalic(fontDescription.style() == FontStyleItalic || fontDescription.style() == FontStyleOblique);
        return fontDataFromFontPlatformData(&platformData, DoNotRetain);
    }

    return nullptr;
}

PassRefPtr<SimpleFontData> FontCache::getLastResortFallbackFont(const FontDescription& description, ShouldRetain shouldRetain)
{
    const FontFaceCreationParams fallbackCreationParams(getFallbackFontFamily(description));
    const FontPlatformData* fontPlatformData = getFontPlatformData(description, fallbackCreationParams);

    // We should at least have Sans or Arial which is the last resort fallback of SkFontHost ports.
    if (!fontPlatformData) {
        DEFINE_STATIC_LOCAL(const FontFaceCreationParams, sansCreationParams, (AtomicString("Sans")));
        fontPlatformData = getFontPlatformData(description, sansCreationParams);
    }
    if (!fontPlatformData) {
        DEFINE_STATIC_LOCAL(const FontFaceCreationParams, arialCreationParams, (AtomicString("Arial")));
        fontPlatformData = getFontPlatformData(description, arialCreationParams);
    }
#if OS(WIN)
    // Try some more Windows-specific fallbacks.
    if (!fontPlatformData) {
        DEFINE_STATIC_LOCAL(const FontFaceCreationParams, msuigothicCreationParams, (AtomicString("MS UI Gothic")));
        fontPlatformData = getFontPlatformData(description, msuigothicCreationParams);
    }
    if (!fontPlatformData) {
        DEFINE_STATIC_LOCAL(const FontFaceCreationParams, mssansserifCreationParams, (AtomicString("Microsoft Sans Serif")));
        fontPlatformData = getFontPlatformData(description, mssansserifCreationParams);
    }
#endif

    ASSERT(fontPlatformData);
    return fontDataFromFontPlatformData(fontPlatformData, shouldRetain);
}

PassRefPtr<SkTypeface> FontCache::createTypeface(const FontDescription& fontDescription, const FontFaceCreationParams& creationParams, CString& name)
{
#if !OS(WIN) && !OS(ANDROID)
    if (creationParams.creationType() == CreateFontByFciIdAndTtcIndex) {
        if (Platform::current()->sandboxSupport())
            return typefaceForFontconfigInterfaceIdAndTtcIndex(creationParams.fontconfigInterfaceId(), creationParams.ttcIndex());
        return adoptRef(SkTypeface::CreateFromFile(creationParams.filename().data(), creationParams.ttcIndex()));
    }
#endif

    AtomicString family = creationParams.family();
    // If we're creating a fallback font (e.g. "-webkit-monospace"), convert the name into
    // the fallback name (like "monospace") that fontconfig understands.
    if (!family.length() || family.startsWith("-webkit-")) {
        name = getFallbackFontFamily(fontDescription).getString().utf8();
    } else {
        // convert the name to utf8
        name = family.utf8();
    }

#if OS(WIN)
    if (s_sideloadedFonts) {
        HashMap<String, RefPtr<SkTypeface>>::iterator sideloadedFont =
            s_sideloadedFonts->find(name.data());
        if (sideloadedFont != s_sideloadedFonts->end())
            return sideloadedFont->value;
    }

    if (m_fontManager) {
        return adoptRef(m_fontManager->matchFamilyStyle(name.data(), fontDescription.skiaFontStyle()));
    }
#endif

#if OS(LINUX)
    // On linux if the fontManager has been overridden then we should be calling the embedder
    // provided font Manager rather than calling SkTypeface::CreateFromName which may redirect the
    // call to the default font Manager.
    if (m_fontManager)
        return adoptRef(m_fontManager->matchFamilyStyle(name.data(), fontDescription.skiaFontStyle()));
#endif

    // FIXME: Use m_fontManager, SkFontStyle and matchFamilyStyle instead of
    // CreateFromName on all platforms.
    int style = SkTypeface::kNormal;
    if (fontDescription.weight() >= FontWeight600)
        style |= SkTypeface::kBold;
    if (fontDescription.style())
        style |= SkTypeface::kItalic;
    return adoptRef(SkTypeface::CreateFromName(name.data(), static_cast<SkTypeface::Style>(style)));
}

#if !OS(WIN)
PassOwnPtr<FontPlatformData> FontCache::createFontPlatformData(const FontDescription& fontDescription,
    const FontFaceCreationParams& creationParams, float fontSize)
{
    CString name;
    RefPtr<SkTypeface> tf(createTypeface(fontDescription, creationParams, name));
    if (!tf)
        return nullptr;

    return adoptPtr(new FontPlatformData(tf,
        name.data(),
        fontSize,
        (fontDescription.weight() >= FontWeight600 && !tf->isBold()) || fontDescription.isSyntheticBold(),
        ((fontDescription.style() == FontStyleItalic || fontDescription.style() == FontStyleOblique) && !tf->isItalic()) || fontDescription.isSyntheticItalic(),
        fontDescription.orientation(),
        fontDescription.useSubpixelPositioning()));
}
#endif // !OS(WIN)

} // namespace blink