1. GroupDocs Documentation
    2. /
    3. GroupDocs.Metadata Product Family
    4. /
    5. GroupDocs.Metadata for Java
    6. /
    7. Developer Guide
    8. /
    9. Advanced Usage
    10. /
    11. Managing metadata for specific formats
    12. /
    13. Other
    14. /
    15. Working with OpenType fonts

    Working with OpenType fonts

    OpenType is a format for scalable computer fonts. It was built on its predecessor TrueType, retaining TrueType’s basic structure and adding many intricate data structures for prescribing typographic behavior.

    Note
    Please find more information on the OpenType format here: https://en.wikipedia.org/wiki/OpenType.

    Reading OpenType metadata

    The GroupDocs.Metadata API supports extracting format-specific information from OpenType font files.

    The following are the steps to read the header of an OpenType file.

    1. Load an OpenType font file
    2. Get the root metadata package
    3. Extract  the native metadata package using the OpenTypeRootPackage.getOpenTypePackage method
    4. Read the OpenType font properties

    advanced_usage.managing_metadata_for_specific_formats.font.OpenTypeReadNativeMetadataProperties

    try (Metadata metadata = new Metadata(Constants.InputTtf)) {
	OpenTypeRootPackage root = metadata.getRootPackageGeneric();

	// Read the OpenType font metadata
	for (OpenTypeFont metadataEntry : root.getOpenTypePackage().getFonts()) {
		// Display the values of some metadata properties
		System.out.println(metadataEntry.getCreated());
		System.out.println(metadataEntry.getDirectionHint());
		System.out.println(metadataEntry.getEmbeddingLicensingRights());
		System.out.println(metadataEntry.getFlags());
		System.out.println(metadataEntry.getFontFamilyName());
		System.out.println(metadataEntry.getFontRevision());
		System.out.println(metadataEntry.getFontSubfamilyName());
		System.out.println(metadataEntry.getFullFontName());
		System.out.println(metadataEntry.getGlyphBounds());
		System.out.println(metadataEntry.getMajorVersion());
		System.out.println(metadataEntry.getMinorVersion());
		System.out.println(metadataEntry.getModified());
		System.out.println(metadataEntry.getSfntVersion());
		System.out.println(metadataEntry.getStyle());
		System.out.println(metadataEntry.getTypographicFamily());
		System.out.println(metadataEntry.getTypographicSubfamily());
		System.out.println(metadataEntry.getWeight());
		System.out.println(metadataEntry.getWidth());

		for (OpenTypeBaseNameRecord nameRecord : metadataEntry.getNames()) {
			System.out.println(nameRecord.getNameID());
			System.out.println(nameRecord.getPlatform());
			System.out.println(nameRecord.getValue());
			if (nameRecord instanceof OpenTypeMacintoshNameRecord) {
				OpenTypeMacintoshNameRecord macintoshNameRecord = (OpenTypeMacintoshNameRecord) nameRecord;
				System.out.println(macintoshNameRecord.getEncoding());
				System.out.println(macintoshNameRecord.getLanguage());
			} else {
				if (nameRecord instanceof OpenTypeUnicodeNameRecord) {
					OpenTypeUnicodeNameRecord unicodeNameRecord = (OpenTypeUnicodeNameRecord) nameRecord;
					System.out.println(unicodeNameRecord.getEncoding());
				} else {
					if (nameRecord instanceof OpenTypeWindowsNameRecord) {
						OpenTypeWindowsNameRecord windowsNameRecord = (OpenTypeWindowsNameRecord) nameRecord;
						System.out.println(windowsNameRecord.getEncoding());
						System.out.println(windowsNameRecord.getLanguage());
					}
				}
			}
		}
	}
}

    Reading digital signatures

    The code snippet bellow demonstrates how to extract information about digital signatures associated with an OpenType font.

    1. Load an OpenType font file
    2. Get the root metadata package
    3. Use the getDigitalSignaturePackage method to get access to all digital signatures associated with the file

    advanced_usage.managing_metadata_for_specific_formats.font.OpenTypeReadDigitalSignatureProperties

    public static void run() {
    try (Metadata metadata = new Metadata(Constants.InputTtf)) {
        OpenTypeRootPackage root = metadata.getRootPackageGeneric();

        if (root.getDigitalSignaturePackage() != null) {
            System.out.println(root.getDigitalSignaturePackage().getFlags());
            for (Cms signature : root.getDigitalSignaturePackage().getSignatures()) {
                System.out.println(signature.getSignTime());

                if (signature.getDigestAlgorithms() != null) {
                    for (Oid signatureDigestAlgorithm : signature.getDigestAlgorithms()) {
                        printOid(signatureDigestAlgorithm);
                    }
                }

                if (signature.getEncapsulatedContent() != null) {
                    printOid(signature.getEncapsulatedContent().getContentType());
                    System.out.println(signature.getEncapsulatedContent().getContentRawData().length);
                }

                if (signature.getCertificates() != null) {
                    for (CmsCertificate certificate : signature.getCertificates()) {
                        System.out.println(certificate.getNotAfter());
                        System.out.println(certificate.getNotBefore());
                        System.out.println(certificate.getRawData().length);
                    }
                }

                if (signature.getSigners() != null) {
                    for (CmsSigner signerInfoEntry : signature.getSigners()) {
                        System.out.println(signerInfoEntry.getSignatureValue());
                        printOid(signerInfoEntry.getDigestAlgorithm());
                        printOid(signerInfoEntry.getSignatureAlgorithm());
                        System.out.println(signerInfoEntry.getSigningTime());
                        printAttributes(signerInfoEntry.getSignedAttributes());
                        printAttributes(signerInfoEntry.getUnsignedAttributes());
                    }
                }
            }
        }
    }
}

private static void printOid(Oid oid) {
    // Display the property name and value of OID
    if (oid != null) {
        System.out.println(oid.getFriendlyName());
        System.out.println(oid.getValue());
    }
}

private static void printAttributes(CmsAttribute[] attributes) {
    //Display the CmsAttributes of an OID
    if (attributes != null) {
        for (CmsAttribute attribute : attributes) {
            printOid(attribute.getOid());
            System.out.println(attribute.getValue());
        }
    }
}

    More resources

    GitHub examples

    You may easily run the code above and see the feature in action in our GitHub examples:

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