Source/platform/fonts/skia/FontCacheSkia.cpp

/*
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 * 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
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 * 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.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#include "config.h"

#if !OS(WIN) && !OS(ANDROID)
#include "SkFontConfigInterface.h"
#endif
#include "SkFontMgr.h"
#include "SkStream.h"
#include "SkTypeface.h"
#include "platform/NotImplemented.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)
static SkStream* streamForFontconfigInterfaceId(int fontconfigInterfaceId)
{
    SkAutoTUnref<SkFontConfigInterface> fci(SkFontConfigInterface::RefGlobal());
    SkFontConfigInterface::FontIdentity fontIdentity;
    fontIdentity.fID = fontconfigInterfaceId;
    return fci->openStream(fontIdentity);
}
#endif

namespace blink {

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);
        return fontDataFromFontPlatformData(&platformData, DoNotRetain);
    }

    return nullptr;
}

#if !OS(WIN) && !OS(ANDROID)
PassRefPtr<SimpleFontData> FontCache::fallbackFontForCharacter(const FontDescription& fontDescription, UChar32 c, const SimpleFontData*)
{
    // First try the specified font with standard style & weight.
    if (fontDescription.style() == FontStyleItalic
        || fontDescription.weight() >= FontWeight600) {
        RefPtr<SimpleFontData> fontData = fallbackOnStandardFontStyle(
            fontDescription, c);
        if (fontData)
            return fontData;
    }

    FontCache::PlatformFallbackFont fallbackFont;
    FontCache::getFontForCharacter(c, fontDescription.locale().ascii().data(), &fallbackFont);
    if (fallbackFont.name.isEmpty())
        return nullptr;

    FontFaceCreationParams creationParams;
    creationParams = FontFaceCreationParams(fallbackFont.filename, fallbackFont.fontconfigInterfaceId, fallbackFont.ttcIndex);

    // Changes weight and/or italic of given FontDescription depends on
    // the result of fontconfig so that keeping the correct font mapping
    // of the given character. See http://crbug.com/32109 for details.
    bool shouldSetSyntheticBold = false;
    bool shouldSetSyntheticItalic = false;
    FontDescription description(fontDescription);
    if (fallbackFont.isBold && description.weight() < FontWeightBold)
        description.setWeight(FontWeightBold);
    if (!fallbackFont.isBold && description.weight() >= FontWeightBold) {
        shouldSetSyntheticBold = true;
        description.setWeight(FontWeightNormal);
    }
    if (fallbackFont.isItalic && description.style() == FontStyleNormal)
        description.setStyle(FontStyleItalic);
    if (!fallbackFont.isItalic && description.style() == FontStyleItalic) {
        shouldSetSyntheticItalic = true;
        description.setStyle(FontStyleNormal);
    }

    FontPlatformData* substitutePlatformData = getFontPlatformData(description, creationParams);
    if (!substitutePlatformData)
        return nullptr;
    FontPlatformData platformData = FontPlatformData(*substitutePlatformData);
    platformData.setSyntheticBold(shouldSetSyntheticBold);
    platformData.setSyntheticItalic(shouldSetSyntheticItalic);
    return fontDataFromFontPlatformData(&platformData, DoNotRetain);
}

#endif // !OS(WIN) && !OS(ANDROID)

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", AtomicString::ConstructFromLiteral)));
        fontPlatformData = getFontPlatformData(description, sansCreationParams);
    }
    if (!fontPlatformData) {
        DEFINE_STATIC_LOCAL(const FontFaceCreationParams, arialCreationParams, (AtomicString("Arial", AtomicString::ConstructFromLiteral)));
        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", AtomicString::ConstructFromLiteral)));
        fontPlatformData = getFontPlatformData(description, msuigothicCreationParams);
    }
    if (!fontPlatformData) {
        DEFINE_STATIC_LOCAL(const FontFaceCreationParams, mssansserifCreationParams, (AtomicString("Microsoft Sans Serif", AtomicString::ConstructFromLiteral)));
        fontPlatformData = getFontPlatformData(description, mssansserifCreationParams);
    }
#endif

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

#if OS(WIN)
static inline SkFontStyle fontStyle(const FontDescription& fontDescription)
{
    int width = static_cast<int>(fontDescription.stretch());
    int weight = (fontDescription.weight() - FontWeight100 + 1) * 100;
    SkFontStyle::Slant slant = fontDescription.style() == FontStyleItalic
        ? SkFontStyle::kItalic_Slant
        : SkFontStyle::kUpright_Slant;
    return SkFontStyle(weight, width, slant);
}

COMPILE_ASSERT(FontStretchUltraCondensed == SkFontStyle::kUltraCondensed_Width,
    FontStretchUltraCondensedMapsTokUltraCondensed_Width);
COMPILE_ASSERT(FontStretchNormal == SkFontStyle::kNormal_Width,
    FontStretchNormalMapsTokNormal_Width);
COMPILE_ASSERT(FontStretchUltraExpanded == SkFontStyle::kUltaExpanded_Width,
    FontStretchUltraExpandedMapsTokUltaExpanded_Width);
#endif

PassRefPtr<SkTypeface> FontCache::createTypeface(const FontDescription& fontDescription, const FontFaceCreationParams& creationParams, CString& name)
{
#if !OS(WIN) && !OS(ANDROID)
    if (creationParams.creationType() == CreateFontByFciIdAndTtcIndex) {
        // TODO(dro): crbug.com/381620 Use creationParams.ttcIndex() after
        // https://code.google.com/p/skia/issues/detail?id=1186 gets fixed.
        SkTypeface* typeface = nullptr;
        if (Platform::current()->sandboxSupport())
            typeface = SkTypeface::CreateFromStream(streamForFontconfigInterfaceId(creationParams.fontconfigInterfaceId()));
        else
            typeface = SkTypeface::CreateFromFile(creationParams.filename().data());

        if (typeface)
            return adoptRef(typeface);
        else
            return nullptr;
    }
#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).string().utf8();
    } else {
        // convert the name to utf8
        name = family.utf8();
    }

    int style = SkTypeface::kNormal;
    if (fontDescription.weight() >= FontWeight600)
        style |= SkTypeface::kBold;
    if (fontDescription.style())
        style |= SkTypeface::kItalic;

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

    if (m_fontManager) {
        return adoptRef(useDirectWrite()
            ? m_fontManager->matchFamilyStyle(name.data(), fontStyle(fontDescription))
            : m_fontManager->legacyCreateTypeface(name.data(), style)
            );
    }
#endif

    // FIXME: Use m_fontManager, SkFontStyle and matchFamilyStyle instead of
    // CreateFromName on all platforms.
    return adoptRef(SkTypeface::CreateFromName(name.data(), static_cast<SkTypeface::Style>(style)));
}

#if !OS(WIN)
FontPlatformData* FontCache::createFontPlatformData(const FontDescription& fontDescription, const FontFaceCreationParams& creationParams, float fontSize)
{
    CString name;
    RefPtr<SkTypeface> tf(createTypeface(fontDescription, creationParams, name));
    if (!tf)
        return 0;

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

} // namespace blink