Improve Signature conformity

@@ -77,21 +77,17 @@ class PdfDocument {
         prev = null,
         _objser = 1 {
     // create the catalog
-    catalog = PdfCatalog(this, PdfPageList(this), pageMode);
+    catalog = PdfCatalog(this, PdfPageList(this), pageMode: pageMode);
   }
 
   PdfDocument.load(
     this.prev, {
-    PdfPageMode pageMode = PdfPageMode.none,
     DeflateCallback? deflate,
     bool compress = true,
     this.verbose = false,
   })  : deflate = compress ? (deflate ?? defaultDeflate) : null,
         _objser = prev!.size,
         version = prev.version {
-    // Now create some standard objects
-    catalog = PdfCatalog(this, PdfPageList(this), pageMode);
-
     // Import the existing document
     prev!.mergeDocument(this);
   }

@@ -125,8 +125,7 @@ class PdfGraphics {
   /// Default font if none selected
   PdfFont? get defaultFont => _page.getDefaultFont();
 
-  bool _altered = false;
-  bool get altered => _altered;
+  bool get altered => _page.altered;
 
   /// Draw a surface on the previously defined shape
   /// set evenOdd to false to use the nonzero winding number rule to determine the region to fill and to true to use the even-odd rule to determine the region to fill
@@ -141,7 +140,7 @@ class PdfGraphics {
     }());
 
     _buf.putString('f${evenOdd ? '*' : ''} ');
-    _altered = true;
+    _page.altered = true;
 
     assert(() {
       if (_page.pdfDocument.verbose) {
@@ -164,7 +163,7 @@ class PdfGraphics {
     }());
 
     _buf.putString('${close ? 's' : 'S'} ');
-    _altered = true;
+    _page.altered = true;
 
     assert(() {
       if (_page.pdfDocument.verbose) {
@@ -185,7 +184,7 @@ class PdfGraphics {
     }());
 
     _buf.putString('h ');
-    _altered = true;
+    _page.altered = true;
 
     assert(() {
       if (_page.pdfDocument.verbose) {
@@ -232,7 +231,7 @@ class PdfGraphics {
     }());
 
     _buf.putString('${close ? 'b' : 'B'}${evenOdd ? '*' : ''} ');
-    _altered = true;
+    _page.altered = true;
 
     assert(() {
       if (_page.pdfDocument.verbose) {
@@ -257,7 +256,7 @@ class PdfGraphics {
     // The shader needs to be registered in the page resources
     _page.addShader(shader);
     _buf.putString('${shader.name} sh ');
-    _altered = true;
+    _page.altered = true;
 
     assert(() {
       if (_page.pdfDocument.verbose) {
@@ -364,7 +363,7 @@ class PdfGraphics {
     }
 
     _buf.putString(' cm ${img.name} Do Q ');
-    _altered = true;
+    _page.altered = true;
 
     assert(() {
       if (_page.pdfDocument.verbose) {
@@ -581,7 +580,7 @@ class PdfGraphics {
       return true;
     }());
 
-    _altered = true;
+    _page.altered = true;
   }
 
   void reset() {

@@ -32,9 +32,11 @@ class PdfCatalog extends PdfObjectDict {
   /// This constructs a Pdf Catalog object
   PdfCatalog(
     PdfDocument pdfDocument,
-    this.pdfPageList,
+    this.pdfPageList, {
     this.pageMode,
-  ) : super(pdfDocument, type: '/Catalog');
+    int objgen = 0,
+    int? objser,
+  }) : super(pdfDocument, type: '/Catalog', objser: objser, objgen: objgen);
 
   /// The pages of the document
   final PdfPageList pdfPageList;
@@ -46,7 +48,7 @@ class PdfCatalog extends PdfObjectDict {
   PdfMetadata? metadata;
 
   /// The initial page mode
-  final PdfPageMode pageMode;
+  final PdfPageMode? pageMode;
 
   /// The anchor names
   PdfNames? names;
@@ -91,7 +93,9 @@ class PdfCatalog extends PdfObjectDict {
     }
 
     // the /PageMode setting
-    params['/PageMode'] = PdfName(_pdfPageModes[pageMode.index]);
+    if (pageMode != null) {
+      params['/PageMode'] = PdfName(_pdfPageModes[pageMode!.index]);
+    }
 
     if (pdfDocument.sign != null) {
       if (pdfDocument.sign!.value.hasMDP) {

@@ -52,6 +52,10 @@ mixin PdfGraphicStream on PdfObjectDict {
   /// The xobjects or other images in the pdf
   final xObjects = <String, PdfXObject>{};
 
+  bool _altered = false;
+  bool get altered => _altered;
+  set altered(bool _) => _altered = true;
+
   /// Add a font to this graphic object
   void addFont(PdfFont font) {
     if (!fonts.containsKey(font.name)) {
@@ -101,12 +105,14 @@ mixin PdfGraphicStream on PdfObjectDict {
     // This holds any resources for this page
     final resources = PdfDict();
 
-    resources['/ProcSet'] = PdfArray(const <PdfName>[
-      PdfName('/PDF'),
-      PdfName('/Text'),
-      PdfName('/ImageB'),
-      PdfName('/ImageC'),
-    ]);
+    if (altered) {
+      resources['/ProcSet'] = PdfArray(const <PdfName>[
+        PdfName('/PDF'),
+        PdfName('/Text'),
+        PdfName('/ImageB'),
+        PdfName('/ImageC'),
+      ]);
+    }
 
     // fonts
     if (fonts.isNotEmpty) {
@@ -141,15 +147,17 @@ mixin PdfGraphicStream on PdfObjectDict {
       resources['/ExtGState'] = pdfDocument.graphicStates.ref();
     }
 
-    if (params.containsKey('/Resources')) {
-      final res = params['/Resources'];
-      if (res is PdfDict) {
-        res.merge(resources);
-        return;
+    if (resources.isNotEmpty) {
+      if (params.containsKey('/Resources')) {
+        final res = params['/Resources'];
+        if (res is PdfDict) {
+          res.merge(resources);
+          return;
+        }
       }
-    }
 
-    params['/Resources'] = resources;
+      params['/Resources'] = resources;
+    }
   }
 }
 

@@ -23,7 +23,11 @@ import 'page.dart';
 /// PdfPageList object
 class PdfPageList extends PdfObjectDict {
   /// This constructs a [PdfPageList] object.
-  PdfPageList(PdfDocument pdfDocument) : super(pdfDocument, type: '/Pages');
+  PdfPageList(
+    PdfDocument pdfDocument, {
+    int objgen = 0,
+    int? objser,
+  }) : super(pdfDocument, type: '/Pages', objgen: objgen, objser: objser);
 
   /// This holds the pages
   final pages = <PdfPage>[];

@@ -85,8 +85,8 @@ class PdfSignature extends PdfObjectDict {
   int output(PdfStream s) {
     value.preSign(this, params);
 
-    _offsetStart = s.offset + '$objser $objgen obj\n'.length;
     final offset = super.output(s);
+    _offsetStart = offset + '$objser $objgen obj\n'.length;
     _offsetEnd = s.offset;
     return offset;
   }

@@ -29,5 +29,7 @@ export 'pdf/format/object_base.dart' hide DeflateCallback, PdfVersion;
 export 'pdf/format/stream.dart';
 export 'pdf/format/string.dart';
 export 'pdf/format/xref.dart';
+export 'pdf/obj/catalog.dart';
 export 'pdf/obj/object.dart';
 export 'pdf/obj/object_stream.dart';
+export 'pdf/obj/page_list.dart';

@@ -67,7 +67,7 @@ class Document {
 
   Document.load(
     PdfDocumentParserBase parser, {
-    PdfPageMode pageMode = PdfPageMode.none,
+    @Deprecated('Not used') PdfPageMode pageMode = PdfPageMode.none,
     DeflateCallback? deflate,
     bool compress = true,
     bool verbose = false,
@@ -80,7 +80,6 @@ class Document {
     String? producer,
   }) : document = PdfDocument.load(
           parser,
-          pageMode: pageMode,
           deflate: deflate,
           compress: compress,
           verbose: verbose,