PDF/A 3b (#1750)

* PDF/A 3b

* PDF/A 3b

* PDF/A, reorganized into multiple files

* PDF/A, make all annotations printable as a default (for pdf/a)

* PDF/A, merging /Names when attaching files

* PDF/A, extended facturx-rdf

* Update pdf/lib/src/pdf/obj/pdfa/README.md

Co-authored-by: Colin Ihlenfeldt <clnmaier@gmail.com>

---------

Co-authored-by: David PHAM-VAN <1387855+DavBfr@users.noreply.github.com>
Co-authored-by: Colin Ihlenfeldt <clnmaier@gmail.com>

@@ -37,6 +37,10 @@ export 'src/pdf/obj/outline.dart';
 export 'src/pdf/obj/page.dart';
 export 'src/pdf/obj/page.dart';
 export 'src/pdf/obj/page_label.dart';
 export 'src/pdf/obj/page_label.dart';
 export 'src/pdf/obj/pattern.dart';
 export 'src/pdf/obj/pattern.dart';
+export 'src/pdf/obj/pdfa/pdfa_attached_files.dart';
+export 'src/pdf/obj/pdfa/pdfa_color_profile.dart';
+export 'src/pdf/obj/pdfa/pdfa_facturx_rdf.dart';
+export 'src/pdf/obj/pdfa/pdfa_rdf.dart';
 export 'src/pdf/obj/shading.dart';
 export 'src/pdf/obj/shading.dart';
 export 'src/pdf/obj/signature.dart';
 export 'src/pdf/obj/signature.dart';
 export 'src/pdf/obj/smask.dart';
 export 'src/pdf/obj/smask.dart';

@@ -173,12 +173,16 @@ abstract class PdfAnnotBase {
     this.border,
     this.border,
     this.content,
     this.content,
     this.name,
     this.name,
-    this.flags,
+    Set<PdfAnnotFlags>? flags,
     this.date,
     this.date,
     this.color,
     this.color,
     this.subject,
     this.subject,
     this.author,
     this.author,
-  });
+  }) {
+    this.flags = flags ?? {
+      PdfAnnotFlags.print,
+    };
+  }
 
 
   /// The subtype of the outline, ie text, note, etc
   /// The subtype of the outline, ie text, note, etc
   final String subtype;
   final String subtype;
@@ -201,7 +205,7 @@ abstract class PdfAnnotBase {
   final String? subject;
   final String? subject;
 
 
   /// Flags specifying various characteristics of the annotation
   /// Flags specifying various characteristics of the annotation
-  final Set<PdfAnnotFlags>? flags;
+  late final Set<PdfAnnotFlags> flags;
 
 
   /// Last modification date
   /// Last modification date
   final DateTime? date;
   final DateTime? date;
@@ -214,11 +218,11 @@ abstract class PdfAnnotBase {
   PdfName? _as;
   PdfName? _as;
 
 
   int get flagValue {
   int get flagValue {
-    if (flags == null || flags!.isEmpty) {
+    if (flags.isEmpty) {
       return 0;
       return 0;
     }
     }
 
 
-    return flags!
+    return flags
         .map<int>((PdfAnnotFlags e) => 1 << e.index)
         .map<int>((PdfAnnotFlags e) => 1 << e.index)
         .reduce((int a, int b) => a | b);
         .reduce((int a, int b) => a | b);
   }
   }
@@ -296,7 +300,7 @@ abstract class PdfAnnotBase {
       params['/NM'] = PdfString.fromString(name!);
       params['/NM'] = PdfString.fromString(name!);
     }
     }
 
 
-    if (flags != null && flags!.isNotEmpty) {
+    if (flags.isNotEmpty) {
       params['/F'] = PdfNum(flagValue);
       params['/F'] = PdfNum(flagValue);
     }
     }
 
 

@@ -26,6 +26,8 @@ import 'object.dart';
 import 'outline.dart';
 import 'outline.dart';
 import 'page_label.dart';
 import 'page_label.dart';
 import 'page_list.dart';
 import 'page_list.dart';
+import 'pdfa/pdfa_attached_files.dart';
+import 'pdfa/pdfa_color_profile.dart';
 
 
 /// Pdf Catalog object
 /// Pdf Catalog object
 class PdfCatalog extends PdfObject<PdfDict> {
 class PdfCatalog extends PdfObject<PdfDict> {
@@ -54,6 +56,12 @@ class PdfCatalog extends PdfObject<PdfDict> {
   /// The document metadata
   /// The document metadata
   PdfMetadata? metadata;
   PdfMetadata? metadata;
 
 
+  /// Colorprofile output intent (Pdf/A)
+  PdfaColorProfile? colorProfile;
+
+  /// Attached files (Pdf/A 3b)
+  PdfaAttachedFiles? attached;
+
   /// The initial page mode
   /// The initial page mode
   final PdfPageMode? pageMode;
   final PdfPageMode? pageMode;
 
 
@@ -89,6 +97,13 @@ class PdfCatalog extends PdfObject<PdfDict> {
       params['/Metadata'] = metadata!.ref();
       params['/Metadata'] = metadata!.ref();
     }
     }
 
 
+    if (attached != null && attached!.isNotEmpty) {
+      //params['/Names'] = attached!.catalogNames();
+      names ??= PdfNames(pdfDocument);
+      names!.params.merge(attached!.catalogNames());
+      params['/AF'] = attached!.catalogAF();
+    }
+
     // the Names object
     // the Names object
     if (names != null) {
     if (names != null) {
       params['/Names'] = names!.ref();
       params['/Names'] = names!.ref();
@@ -158,5 +173,9 @@ class PdfCatalog extends PdfObject<PdfDict> {
             {'/Font': fontRefs});
             {'/Font': fontRefs});
       }
       }
     }
     }
+
+    if (colorProfile != null) {
+      params['/OutputIntents'] = colorProfile!.outputIntents();
+    }
   }
   }
 }
 }

@@ -45,7 +45,8 @@ class PdfMetadata extends PdfObject<PdfDictStream> {
   @override
   @override
   void prepare() {
   void prepare() {
     super.prepare();
     super.prepare();
-    params['/SubType'] = const PdfName('/XML');
+    params['/Type'] = const PdfName('/Metadata');
+    params['/Subtype'] = const PdfName('/XML');
     params.data = Uint8List.fromList(utf8.encode(metadata.toString()));
     params.data = Uint8List.fromList(utf8.encode(metadata.toString()));
   }
   }
 }
 }

+Here are some classes to help you creating PDF/A compliant PDFs
+plus embedding Facturx invoices.
+
+### Rules
+
+1. Your PDF must only use embedded Fonts,
+2. For now you cannot use any Annotations in your PDF
+3. You must include a special Meta-XML, use below "PdfaRdf" and put the reuslting XML document into your documents metadata
+4. You must include a Colorprofile, use the below "PdfaColorProfile" and embed the contents of "sRGB2014.icc"
+5. Optionally attach an InvoiceXML using "PdfaFacturxRdf" and "PdfaAttachedFiles"
+
+### Example
+
+```
+pw.Document pdf = pw.Document(
+  ...
+  metadata: PdfaRdf(
+    ...
+    invoiceRdf: PdfaFacturxRdf().create()
+  ).create(),
+);
+
+PdfaColorProfile(
+  pdf.document,
+  File('sRGB2014.icc').readAsBytesSync(),
+);
+
+PdfaAttachedFiles(
+  pdf.document,
+  {
+    'factur-x.xml': myInvoiceXmlDocument,
+  },
+);
+```
+
+### Validating
+
+https://demo.verapdf.org
+https://avepdf.com/pdfa-validation
+https://www.mustangproject.org

+import 'dart:convert';
+import 'dart:typed_data';
+
+import '../../document.dart';
+import '../../format/array.dart';
+import '../../format/base.dart';
+import '../../format/dict.dart';
+import '../../format/dict_stream.dart';
+import '../../format/indirect.dart';
+import '../../format/name.dart';
+import '../../format/num.dart';
+import '../../format/object_base.dart';
+import '../../format/stream.dart';
+import '../../format/string.dart';
+import '../object.dart';
+import 'pdfa_date_format.dart';
+
+class PdfaAttachedFiles {
+  PdfaAttachedFiles(
+    PdfDocument pdfDocument,
+    Map<String, String> files,
+  ) {
+    for (var entry in files.entries) {
+      _files.add(
+        _AttachedFileSpec(
+          pdfDocument,
+          _AttachedFile(
+            pdfDocument,
+            entry.key,
+            entry.value,
+          ),
+        ),
+      );
+    }
+    _names = _AttachedFileNames(
+      pdfDocument,
+      _files,
+    );
+    pdfDocument.catalog.attached = this;
+  }
+
+  final List<_AttachedFileSpec> _files = [];
+
+  late final _AttachedFileNames _names;
+
+  bool get isNotEmpty => _files.isNotEmpty;
+
+  PdfDict catalogNames() {
+    return PdfDict({
+      '/EmbeddedFiles': _names.ref(),
+    });
+  }
+
+  PdfArray catalogAF() {
+    final tmp = <PdfIndirect>[];
+    for (var spec in _files) {
+      tmp.add(spec.ref());
+    }
+    return PdfArray(tmp);
+  }
+}
+
+class _AttachedFileNames extends PdfObject<PdfDict> {
+  _AttachedFileNames(
+    PdfDocument pdfDocument,
+    this._files,
+  ) : super(
+          pdfDocument,
+          params: PdfDict(),
+        );
+  final List<_AttachedFileSpec> _files;
+
+  @override
+  void prepare() {
+    super.prepare();
+    params['/Names'] = PdfArray(
+      [
+        _PdfRaw(0, _files.first),
+      ],
+    );
+  }
+}
+
+class _AttachedFileSpec extends PdfObject<PdfDict> {
+  _AttachedFileSpec(
+    PdfDocument pdfDocument,
+    this._file,
+  ) : super(
+          pdfDocument,
+          params: PdfDict(),
+        );
+  final _AttachedFile _file;
+
+  @override
+  void prepare() {
+    super.prepare();
+
+    params['/Type'] = const PdfName('/Filespec');
+    params['/F'] = PdfString(
+      Uint8List.fromList(_file.fileName.codeUnits),
+    );
+    params['/UF'] = PdfString(
+      Uint8List.fromList(_file.fileName.codeUnits),
+    );
+    params['/EF'] = PdfDict({
+      '/F': _file.ref(),
+    });
+    params['/AFRelationship'] = const PdfName('/Unspecified');
+  }
+}
+
+class _AttachedFile extends PdfObject<PdfDictStream> {
+  _AttachedFile(
+    PdfDocument pdfDocument,
+    this.fileName,
+    this.content,
+  ) : super(
+          pdfDocument,
+          params: PdfDictStream(
+            compress: false,
+            encrypt: false,
+          ),
+        );
+
+  final String fileName;
+  final String content;
+
+  @override
+  void prepare() {
+    super.prepare();
+
+    final modDate = PdfaDateFormat().format(dt: DateTime.now());
+    params['/Type'] = const PdfName('/EmbeddedFile');
+    params['/Subtype'] = const PdfName('/application/octet-stream');
+    params['/Params'] = PdfDict({
+      '/Size': PdfNum(content.codeUnits.length),
+      '/ModDate': PdfString(
+        Uint8List.fromList('D:$modDate+00\'00\''.codeUnits),
+      ),
+    });
+
+    params.data = Uint8List.fromList(utf8.encode(content));
+  }
+}
+
+class _PdfRaw extends PdfDataType {
+  const _PdfRaw(
+    this.nr,
+    this.spec,
+  );
+
+  final int nr;
+  final _AttachedFileSpec spec;
+
+  @override
+  void output(
+    PdfObjectBase o,
+    PdfStream s, [
+    int? indent,
+  ]) {
+    s.putString('(${nr.toString().padLeft(3, '0')}) ${spec.ref()}');
+  }
+}

+import 'dart:typed_data';
+
+import '../../document.dart';
+import '../../format/array.dart';
+import '../../format/dict.dart';
+import '../../format/dict_stream.dart';
+import '../../format/name.dart';
+import '../../format/num.dart';
+import '../../format/string.dart';
+import '../object.dart';
+
+class PdfaColorProfile extends PdfObject<PdfDictStream> {
+  PdfaColorProfile(
+    PdfDocument pdfDocument,
+    this.icc,
+  ) : super(
+          pdfDocument,
+          params: PdfDictStream(
+            compress: false,
+            encrypt: false,
+          ),
+        ) {
+    pdfDocument.catalog.colorProfile = this;
+  }
+
+  final Uint8List icc;
+
+  @override
+  void prepare() {
+    super.prepare();
+    params['/N'] = const PdfNum(3);
+    params.data = icc;
+  }
+
+  PdfArray outputIntents() {
+    return PdfArray<PdfDict>([
+      PdfDict({
+        '/Type': const PdfName('/OutputIntent'),
+        '/S': const PdfName('/GTS_PDFA1'),
+        '/OutputConditionIdentifier':
+            PdfString(Uint8List.fromList('sRGB2014.icc'.codeUnits)),
+        '/Info': PdfString(Uint8List.fromList('sRGB2014.icc'.codeUnits)),
+        '/RegistryName':
+            PdfString(Uint8List.fromList('http://www.color.org'.codeUnits)),
+        '/DestOutputProfile': ref(),
+      }),
+    ]);
+  }
+}

+class PdfaDateFormat {
+  String format({
+    required DateTime dt,
+    bool asIso = false,
+  }) {
+    final year = dt.year.toString().padLeft(4, '0');
+    final month = dt.month.toString().padLeft(2, '0');
+    final day = dt.day.toString().padLeft(2, '0');
+    final hour = dt.hour.toString().padLeft(2, '0');
+    final minute = dt.minute.toString().padLeft(2, '0');
+    final second = dt.second.toString().padLeft(2, '0');
+
+    if (asIso) {
+      // "yyyy-MM-dd'T'HH:mm:ss"
+      return '$year-$month-${day}T$hour:$minute:$second';
+    }
+    // "yyyyMMddHHmmss"
+    return '$year$month$day$hour$minute$second';
+  }
+}

+class PdfaFacturxRdf {
+  String create({
+    String filename = 'factur-x.xml',
+    String namespace = 'urn:cen.eu:invoice:1p0:schema#',
+    String conformanceLevel = 'BASIC',
+    String version = '1.0',
+  }) {
+    return '''
+    
+<rdf:Description xmlns:fx="$namespace" rdf:about="">
+  <fx:DocumentType>INVOICE</fx:DocumentType>
+  <fx:DocumentFileName>$filename</fx:DocumentFileName>
+  <fx:Version>$version</fx:Version>
+  <fx:ConformanceLevel>$conformanceLevel</fx:ConformanceLevel>
+</rdf:Description>
+    
+<rdf:Description xmlns:pdfaExtension="http://www.aiim.org/pdfa/ns/extension/"
+  xmlns:pdfaField="http://www.aiim.org/pdfa/ns/field#"
+  xmlns:pdfaProperty="http://www.aiim.org/pdfa/ns/property#"
+  xmlns:pdfaSchema="http://www.aiim.org/pdfa/ns/schema#"
+  xmlns:pdfaType="http://www.aiim.org/pdfa/ns/type#"
+  rdf:about=""
+>
+  <pdfaExtension:schemas>
+    <rdf:Bag>
+      <rdf:li rdf:parseType="Resource">
+        <pdfaSchema:schema>Invoice PDFA Extension Schema</pdfaSchema:schema>
+        <pdfaSchema:namespaceURI>$namespace</pdfaSchema:namespaceURI>
+        <pdfaSchema:prefix>fx</pdfaSchema:prefix>
+        <pdfaSchema:property>
+          <rdf:Seq>
+            <rdf:li rdf:parseType="Resource">
+              <pdfaProperty:name>DocumentFileName</pdfaProperty:name>
+              <pdfaProperty:valueType>Text</pdfaProperty:valueType>
+              <pdfaProperty:category>external</pdfaProperty:category>
+              <pdfaProperty:description>name of the embedded XML invoice file</pdfaProperty:description>
+            </rdf:li>
+              <rdf:li rdf:parseType="Resource">
+              <pdfaProperty:name>DocumentType</pdfaProperty:name>
+              <pdfaProperty:valueType>Text</pdfaProperty:valueType>
+              <pdfaProperty:category>external</pdfaProperty:category>
+              <pdfaProperty:description>INVOICE</pdfaProperty:description>
+            </rdf:li>
+              <rdf:li rdf:parseType="Resource">
+              <pdfaProperty:name>Version</pdfaProperty:name>
+              <pdfaProperty:valueType>Text</pdfaProperty:valueType>
+              <pdfaProperty:category>external</pdfaProperty:category>
+              <pdfaProperty:description>The actual version of the ZUGFeRD data</pdfaProperty:description>
+            </rdf:li>
+              <rdf:li rdf:parseType="Resource">
+              <pdfaProperty:name>ConformanceLevel</pdfaProperty:name>
+              <pdfaProperty:valueType>Text</pdfaProperty:valueType>
+              <pdfaProperty:category>external</pdfaProperty:category>
+              <pdfaProperty:description>The conformance level of the ZUGFeRD data</pdfaProperty:description>
+            </rdf:li>
+          </rdf:Seq>
+        </pdfaSchema:property>
+      </rdf:li>
+    </rdf:Bag>
+  </pdfaExtension:schemas>
+</rdf:Description>
+''';
+  }
+}

+import 'package:xml/xml.dart';
+
+import 'pdfa_date_format.dart';
+
+class PdfaRdf {
+  PdfaRdf({
+    this.title,
+    this.author,
+    this.creator,
+    this.subject,
+    this.keywords,
+    this.producer,
+    DateTime? creationDate,
+    this.invoiceRdf = '',
+  }) {
+    this.creationDate = creationDate ?? DateTime.now();
+  }
+
+  final String? title;
+  final String? author;
+  final String? creator;
+  final String? subject;
+  final String? keywords;
+  final String? producer;
+  late final DateTime creationDate;
+  final String invoiceRdf;
+
+  XmlDocument? create() {
+    var createDate = PdfaDateFormat().format(dt: creationDate, asIso: true);
+    final offset = creationDate.timeZoneOffset;
+    final hours =
+        offset.inHours > 0 ? offset.inHours : 1; // For fixing divide by 0
+    if (!offset.isNegative) {
+      createDate =
+          "$createDate+${offset.inHours.toString().padLeft(2, '0')}:${(offset.inMinutes % (hours * 60)).toString().padLeft(2, '0')}";
+    } else {
+      createDate =
+          "$createDate-${(-offset.inHours).toString().padLeft(2, '0')}:${(offset.inMinutes % (hours * 60)).toString().padLeft(2, '0')}";
+    }
+
+    return XmlDocument.parse('''
+<?xpacket begin="" id="W5M0MpCehiHzreSzNTczkc9d"?>
+<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+  <rdf:Description rdf:about="" xmlns:pdf="http://ns.adobe.com/pdf/1.3/">
+    <pdf:Producer>$producer</pdf:Producer>
+    <pdf:Keywords>$keywords</pdf:Keywords>
+  </rdf:Description>
+  <rdf:Description rdf:about="" xmlns:xmp="http://ns.adobe.com/xap/1.0/">
+    <xmp:CreateDate>$createDate</xmp:CreateDate>
+    <xmp:CreatorTool>$creator</xmp:CreatorTool>
+  </rdf:Description>
+  <rdf:Description rdf:about="" xmlns:dc="http://purl.org/dc/elements/1.1/">
+    <dc:creator><rdf:Seq><rdf:li>$author</rdf:li></rdf:Seq></dc:creator>
+    <dc:title><rdf:Alt><rdf:li xml:lang="x-default">$title</rdf:li></rdf:Alt></dc:title>
+    <dc:description><rdf:Alt><rdf:li xml:lang="x-default">$subject</rdf:li></rdf:Alt></dc:description>
+  </rdf:Description>
+  <rdf:Description rdf:about="" xmlns:pdfaid="http://www.aiim.org/pdfa/ns/id/">
+    <pdfaid:part>3</pdfaid:part>
+    <pdfaid:conformance>B</pdfaid:conformance>
+  </rdf:Description>
+  
+  $invoiceRdf
+  
+</rdf:RDF>
+<?xpacket end="r"?>
+''');
+  }
+}