SkPDFMetadata Namespace Reference

Functions
std::unique_ptr< SkPDFObject >	MakeDocumentInformationDict (const SkPDF::Metadata &)
SkUUID	CreateUUID (const SkPDF::Metadata &)
std::unique_ptr< SkPDFObject >	MakePdfId (const SkUUID &doc, const SkUUID &instance)
SkPDFIndirectReference	MakeXMPObject (const SkPDF::Metadata &metadata, const SkUUID &doc, const SkUUID &instance, SkPDFDocument *)

Function Documentation

CreateUUID()

SkUUID SkPDFMetadata::CreateUUID

(

const SkPDF::Metadata &

metadata

)

Definition at line 86 of file SkPDFMetadata.cpp.

                                                              {
    // The main requirement is for the UUID to be unique; the exact
    // format of the data that will be hashed is not important.
    SkMD5 md5;
    const char uuidNamespace[] = "org.skia.pdf\n";
    md5.writeText(uuidNamespace);
    double msec = SkTime::GetMSecs();
    md5.write(&msec, sizeof(msec));
    SkPDF::DateTime dateTime;
    SkPDFUtils::GetDateTime(&dateTime);
    md5.write(&dateTime, sizeof(dateTime));
    md5.write(&metadata.fCreation, sizeof(metadata.fCreation));
    md5.write(&metadata.fModified, sizeof(metadata.fModified));
 
    for (const auto keyValuePtr : gMetadataKeys) {
        md5.writeText(keyValuePtr.key);
        md5.write("\037", 1);
        const SkString& value = metadata.*(keyValuePtr.valuePtr);
        md5.write(value.c_str(), value.size());
        md5.write("\036", 1);
    }
    SkMD5::Digest digest = md5.finish();
    // See RFC 4122, page 6-7.
    digest.data[6] = (digest.data[6] & 0x0F) | 0x30;
    digest.data[8] = (digest.data[6] & 0x3F) | 0x80;
    static_assert(sizeof(digest) == sizeof(SkUUID), "uuid_size");
    SkUUID uuid;
    memcpy((void*)&uuid, &digest, sizeof(digest));
    return uuid;
}

MakeDocumentInformationDict()

std::unique_ptr< SkPDFObject > SkPDFMetadata::MakeDocumentInformationDict

(

const SkPDF::Metadata &

metadata

)

Definition at line 68 of file SkPDFMetadata.cpp.

                                       {
    auto dict = SkPDFMakeDict();
    for (const auto keyValuePtr : gMetadataKeys) {
        const SkString& value = metadata.*(keyValuePtr.valuePtr);
        if (value.size() > 0) {
            dict->insertTextString(keyValuePtr.key, value);
        }
    }
    if (metadata.fCreation != kZeroTime) {
        dict->insertTextString("CreationDate", pdf_date(metadata.fCreation));
    }
    if (metadata.fModified != kZeroTime) {
        dict->insertTextString("ModDate", pdf_date(metadata.fModified));
    }
    return dict;
}

MakePdfId()

std::unique_ptr< SkPDFObject > SkPDFMetadata::MakePdfId	(	const SkUUID &	doc,
		const SkUUID &	instance
	)

Definition at line 117 of file SkPDFMetadata.cpp.

                                                                                             {
    // /ID [ <81b14aafa313db63dbd6f981e49f94f4>
    //       <81b14aafa313db63dbd6f981e49f94f4> ]
    auto array = SkPDFMakeArray();
    static_assert(sizeof(SkUUID) == 16, "uuid_size");
    array->appendByteString(SkString(reinterpret_cast<const char*>(&doc     ), sizeof(SkUUID)));
    array->appendByteString(SkString(reinterpret_cast<const char*>(&instance), sizeof(SkUUID)));
    return array;
}

MakeXMPObject()

SkPDFIndirectReference SkPDFMetadata::MakeXMPObject	(	const SkPDF::Metadata &	metadata,
		const SkUUID &	doc,
		const SkUUID &	instance,
		SkPDFDocument *	docPtr
	)

Definition at line 235 of file SkPDFMetadata.cpp.

                               {
    static const char templateString[] =
            "<?xpacket begin=\"\" id=\"W5M0MpCehiHzreSzNTczkc9d\"?>\n"
            "<x:xmpmeta xmlns:x=\"adobe:ns:meta/\"\n"
            " x:xmptk=\"Adobe XMP Core 5.4-c005 78.147326, "
            "2012/08/23-13:03:03\">\n"
            "<rdf:RDF "
            "xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\">\n"
            "<rdf:Description rdf:about=\"\"\n"
            " xmlns:xmp=\"http://ns.adobe.com/xap/1.0/\"\n"
            " xmlns:dc=\"http://purl.org/dc/elements/1.1/\"\n"
            " xmlns:xmpMM=\"http://ns.adobe.com/xap/1.0/mm/\"\n"
            " xmlns:pdf=\"http://ns.adobe.com/pdf/1.3/\"\n"
            " xmlns:pdfaid=\"http://www.aiim.org/pdfa/ns/id/\">\n"
            "<pdfaid:part>2</pdfaid:part>\n"
            "<pdfaid:conformance>B</pdfaid:conformance>\n"
            "%s"  // ModifyDate
            "%s"  // CreateDate
            "%s"  // xmp:CreatorTool
            "<dc:format>application/pdf</dc:format>\n"
            "%s"  // dc:title
            "%s"  // dc:description
            "%s"  // author
            "%s"  // keywords
            "<xmpMM:DocumentID>uuid:%s</xmpMM:DocumentID>\n"
            "<xmpMM:InstanceID>uuid:%s</xmpMM:InstanceID>\n"
            "%s"  // pdf:Producer
            "%s"  // pdf:Keywords
            "</rdf:Description>\n"
            "</rdf:RDF>\n"
            "</x:xmpmeta>\n"  // Note:  the standard suggests 4k of padding.
            "<?xpacket end=\"w\"?>\n";
 
    SkString creationDate;
    SkString modificationDate;
    if (metadata.fCreation != kZeroTime) {
        SkString tmp;
        metadata.fCreation.toISO8601(&tmp);
        SkASSERT(0 == count_xml_escape_size(tmp));
        // YYYY-mm-ddTHH:MM:SS[+|-]ZZ:ZZ; no need to escape
        creationDate = SkStringPrintf("<xmp:CreateDate>%s</xmp:CreateDate>\n",
                                      tmp.c_str());
    }
    if (metadata.fModified != kZeroTime) {
        SkString tmp;
        metadata.fModified.toISO8601(&tmp);
        SkASSERT(0 == count_xml_escape_size(tmp));
        modificationDate = SkStringPrintf(
                "<xmp:ModifyDate>%s</xmp:ModifyDate>\n", tmp.c_str());
    }
    SkString title =
            escape_xml(metadata.fTitle,
                       "<dc:title><rdf:Alt><rdf:li xml:lang=\"x-default\">",
                       "</rdf:li></rdf:Alt></dc:title>\n");
    SkString author =
            escape_xml(metadata.fAuthor, "<dc:creator><rdf:Seq><rdf:li>",
                       "</rdf:li></rdf:Seq></dc:creator>\n");
    // TODO: in theory, XMP can support multiple authors.  Split on a delimiter?
    SkString subject = escape_xml(
            metadata.fSubject,
            "<dc:description><rdf:Alt><rdf:li xml:lang=\"x-default\">",
            "</rdf:li></rdf:Alt></dc:description>\n");
    SkString keywords1 =
            escape_xml(metadata.fKeywords, "<dc:subject><rdf:Bag><rdf:li>",
                       "</rdf:li></rdf:Bag></dc:subject>\n");
    SkString keywords2 = escape_xml(metadata.fKeywords, "<pdf:Keywords>",
                                    "</pdf:Keywords>\n");
    // TODO: in theory, keywords can be a list too.
 
    SkString producer = escape_xml(metadata.fProducer, "<pdf:Producer>", "</pdf:Producer>\n");
 
    SkString creator = escape_xml(metadata.fCreator, "<xmp:CreatorTool>",
                                  "</xmp:CreatorTool>\n");
    SkString documentID = uuid_to_string(doc);  // no need to escape
    SkASSERT(0 == count_xml_escape_size(documentID));
    SkString instanceID = uuid_to_string(instance);
    SkASSERT(0 == count_xml_escape_size(instanceID));
 
 
    auto value = SkStringPrintf(
            templateString, modificationDate.c_str(), creationDate.c_str(),
            creator.c_str(), title.c_str(), subject.c_str(), author.c_str(),
            keywords1.c_str(), documentID.c_str(), instanceID.c_str(),
            producer.c_str(), keywords2.c_str());
 
    std::unique_ptr<SkPDFDict> dict = SkPDFMakeDict("Metadata");
    dict->insertName("Subtype", "XML");
    return SkPDFStreamOut(std::move(dict),
                          SkMemoryStream::MakeCopy(value.c_str(), value.size()),
                          docPtr, SkPDFSteamCompressionEnabled::No);
}