Source/core/platform/graphics/skia/FontCustomPlatformData.cpp

/*
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#include "config.h"
#include "core/platform/graphics/skia/FontCustomPlatformData.h"

#if OS(WINDOWS)
#include "core/platform/graphics/opentype/OpenTypeUtilities.h"
#elif OS(UNIX)
#include "third_party/skia/include/core/SkStream.h"
#include "core/platform/graphics/skia/SkiaSharedBufferStream.h"
#endif

#include "core/platform/LayoutTestSupport.h"
#include "core/platform/NotImplemented.h"
#include "core/platform/SharedBuffer.h"
#include "core/platform/graphics/FontPlatformData.h"
#include "core/platform/graphics/opentype/OpenTypeSanitizer.h"

#if OS(WINDOWS)
#include <objbase.h>
#include <wtf/text/Base64.h>
#endif

namespace WebCore {

FontCustomPlatformData::~FontCustomPlatformData()
{
#if OS(WINDOWS)
    if (m_fontReference)
        RemoveFontMemResourceEx(m_fontReference);
#elif OS(UNIX)
    if (m_fontReference)
        m_fontReference->unref();
#endif
}

FontPlatformData FontCustomPlatformData::fontPlatformData(int size, bool bold, bool italic, FontOrientation orientation, FontWidthVariant)
{
#if OS(WINDOWS)
    ASSERT(m_fontReference);

    LOGFONT logFont;
    // m_name comes from createUniqueFontName, which, in turn, gets
    // it from base64-encoded uuid (128-bit). So, m_name
    // can never be longer than LF_FACESIZE (32).
    if (m_name.length() + 1 >= LF_FACESIZE) {
        ASSERT_NOT_REACHED();
        return FontPlatformData();
    }
    unsigned len = m_name.copyTo(logFont.lfFaceName, 0, LF_FACESIZE - 1);
    logFont.lfFaceName[len] = '\0';

    // FIXME: almost identical to FillLogFont in FontCacheWin.cpp.
    // Need to refactor.
    logFont.lfHeight = -size;
    logFont.lfWidth = 0;
    logFont.lfEscapement = 0;
    logFont.lfOrientation = 0;
    logFont.lfUnderline = false;
    logFont.lfStrikeOut = false;
    logFont.lfCharSet = DEFAULT_CHARSET;
    logFont.lfOutPrecision = OUT_TT_ONLY_PRECIS;
    logFont.lfQuality = isRunningLayoutTest() ?
                        NONANTIALIASED_QUALITY :
                        DEFAULT_QUALITY; // Honor user's desktop settings.
    logFont.lfPitchAndFamily = DEFAULT_PITCH | FF_DONTCARE;
    logFont.lfItalic = italic;
    logFont.lfWeight = bold ? FW_BOLD : FW_DONTCARE;

    HFONT hfont = CreateFontIndirect(&logFont);
    return FontPlatformData(hfont, size, orientation);
#elif OS(UNIX)
    ASSERT(m_fontReference);
    return FontPlatformData(m_fontReference, "", size, bold && !m_fontReference->isBold(), italic && !m_fontReference->isItalic(), orientation);
#else
    notImplemented();
    return FontPlatformData();
#endif
}

#if OS(WINDOWS)
// Creates a unique and unpredictable font name, in order to avoid collisions and to
// not allow access from CSS.
static String createUniqueFontName()
{
    GUID fontUuid;
    CoCreateGuid(&fontUuid);

    String fontName = base64Encode(reinterpret_cast<char*>(&fontUuid), sizeof(fontUuid));
    ASSERT(fontName.length() < LF_FACESIZE);
    return fontName;
}
#endif

FontCustomPlatformData* createFontCustomPlatformData(SharedBuffer* buffer)
{
    ASSERT_ARG(buffer, buffer);

    OpenTypeSanitizer sanitizer(buffer);
    RefPtr<SharedBuffer> transcodeBuffer = sanitizer.sanitize();
    if (!transcodeBuffer)
        return 0; // validation failed.
    buffer = transcodeBuffer.get();

#if OS(WINDOWS)
    // Introduce the font to GDI. AddFontMemResourceEx should be used with care, because it will pollute the process's
    // font namespace (Windows has no API for creating an HFONT from data without exposing the font to the
    // entire process first).
    String fontName = createUniqueFontName();
    HANDLE fontReference = renameAndActivateFont(buffer, fontName);
    if (!fontReference)
        return 0;
    return new FontCustomPlatformData(fontReference, fontName);
#elif OS(UNIX)
    SkiaSharedBufferStream* stream = new SkiaSharedBufferStream(buffer);
    SkTypeface* typeface = SkTypeface::CreateFromStream(stream);
    stream->unref();
    if (!typeface)
        return 0;
    return new FontCustomPlatformData(typeface);
#else
    notImplemented();
    return 0;
#endif
}

bool FontCustomPlatformData::supportsFormat(const String& format)
{
    return equalIgnoringCase(format, "truetype") || equalIgnoringCase(format, "opentype") || OpenTypeSanitizer::supportsFormat(format);
}

}