Simplify PDF generation

@@ -20,8 +20,11 @@ import 'dart:typed_data';
 import 'package:crypto/crypto.dart';
 
 import 'document_parser.dart';
+import 'format/array.dart';
+import 'format/num.dart';
 import 'format/object_base.dart';
 import 'format/stream.dart';
+import 'format/string.dart';
 import 'format/xref.dart';
 import 'graphic_state.dart';
 import 'io/vm.dart' if (dart.library.js) 'io/js.dart';
@@ -36,7 +39,6 @@ import 'obj/page.dart';
 import 'obj/page_label.dart';
 import 'obj/page_list.dart';
 import 'obj/signature.dart';
-import 'output.dart';
 
 /// Display hint for the PDF viewer
 enum PdfPageMode {
@@ -200,24 +202,36 @@ class PdfDocument {
 
   /// This writes the document to an OutputStream.
   Future<void> _write(PdfStream os) async {
-    final pos = PdfOutput(os, version, verbose);
-
-    // Write each object to the [PdfStream]. We call via the output
-    // as that builds the xref table
-    objects.where((e) => e.inUse).forEach(pos.write);
-    var lastFree = 0;
-    for (final obj in objects.where((e) => !e.inUse)) {
-      pos.xref.add(PdfXref(
-        obj.objser,
-        lastFree,
-        generation: obj.objgen,
-        type: PdfCrossRefEntryType.free,
-      ));
-      lastFree = obj.objser;
+    PdfSignature? signature;
+
+    final xref = PdfXrefTable();
+
+    for (final ob in objects.where((e) => e.inUse)) {
+      ob.prepare();
+      if (ob is PdfInfo) {
+        xref.params['/Info'] = ob.ref();
+      } else if (ob is PdfEncryption) {
+        xref.params['/Encrypt'] = ob.ref();
+      } else if (ob is PdfSignature) {
+        assert(signature == null, 'Only one document signature is allowed');
+        signature = ob;
+      }
+      xref.objects.add(ob);
     }
 
-    // Finally close the output, which writes the xref table.
-    await pos.close();
+    final id =
+        PdfString(documentID, format: PdfStringFormat.binary, encrypted: false);
+    xref.params['/ID'] = PdfArray([id, id]);
+
+    if (prev != null) {
+      xref.params['/Prev'] = PdfNum(prev!.xrefOffset);
+    }
+
+    xref.output(catalog, os);
+
+    if (signature != null) {
+      await signature.writeSignature(os);
+    }
   }
 
   /// Generate the PDF document as a memory file

@@ -30,7 +30,7 @@ abstract class PdfDataType {
 
   PdfStream _toStream() {
     final s = PdfStream();
-    output(const PdfObjectBase(objser: 0), s);
+    output(PdfObjectBase(objser: 0, params: this), s);
     return s;
   }
 

@@ -2,7 +2,7 @@ import 'dart:math' as math;
 
 import 'package:meta/meta.dart';
 
-import '../format/stream.dart';
+import 'stream.dart';
 
 mixin PdfDiagnostic {
   static const _maxSize = 300;
@@ -15,6 +15,8 @@ mixin PdfDiagnostic {
 
   int get elapsedStopwatch => _stopwatch?.elapsedMicroseconds ?? 0;
 
+  int size = 0;
+
   @protected
   @mustCallSuper
   void debugFill(String value) {
@@ -29,10 +31,11 @@ mixin PdfDiagnostic {
     }());
   }
 
-  void setInsertion(PdfStream os) {
+  void setInsertion(PdfStream os, [int size = _maxSize]) {
     assert(() {
+      this.size = size;
       _offset = os.offset;
-      os.putComment(' ' * _maxSize);
+      os.putComment(' ' * size);
       return true;
     }());
   }
@@ -45,7 +48,7 @@ mixin PdfDiagnostic {
         final b = o.output();
         os.setBytes(
           _offset!,
-          b.sublist(0, math.min(_maxSize + 2, b.lengthInBytes - 1)),
+          b.sublist(0, math.min(size + 2, b.lengthInBytes - 1)),
         );
       }
       return true;

@@ -99,6 +99,6 @@ class PdfDictStream extends PdfDict<PdfDataType> {
     }
     s.putString('stream\n');
     s.putBytes(_data);
-    s.putString('\nendstream\n');
+    s.putString('\nendstream');
   }
 }

@@ -16,7 +16,10 @@
 
 import 'dart:typed_data';
 
+import 'base.dart';
+import 'diagnostic.dart';
 import 'indirect.dart';
+import 'stream.dart';
 
 /// Callback used to compress the data
 typedef DeflateCallback = List<int> Function(List<int> data);
@@ -34,10 +37,11 @@ enum PdfVersion {
   pdf_1_5,
 }
 
-class PdfObjectBase {
-  const PdfObjectBase({
+class PdfObjectBase<T extends PdfDataType> with PdfDiagnostic {
+  PdfObjectBase({
     required this.objser,
     this.objgen = 0,
+    required this.params,
   });
 
   /// This is the unique serial number for this object.
@@ -46,6 +50,8 @@ class PdfObjectBase {
   /// This is the generation number for this object.
   final int objgen;
 
+  final T params;
+
   /// Callback used to compress the data
   DeflateCallback? get deflate => null;
 
@@ -59,4 +65,15 @@ class PdfObjectBase {
 
   /// Returns the unique serial number in Pdf format
   PdfIndirect ref() => PdfIndirect(objser, objgen);
+
+  void output(PdfStream s) {
+    s.putString('$objser $objgen obj\n');
+    writeContent(s);
+    s.putString('endobj\n');
+  }
+
+  void writeContent(PdfStream s) {
+    params.output(this, s, verbose ? 0 : null);
+    s.putByte(0x0a);
+  }
 }

@@ -19,6 +19,7 @@ import 'dart:typed_data';
 
 import 'array.dart';
 import 'base.dart';
+import 'diagnostic.dart';
 import 'dict.dart';
 import 'dict_stream.dart';
 import 'indirect.dart';
@@ -95,16 +96,17 @@ class PdfXref {
   int get hashCode => offset;
 }
 
-class PdfXrefTable extends PdfDataType {
+class PdfXrefTable extends PdfDataType with PdfDiagnostic {
   PdfXrefTable();
 
-  /// Contains offsets of each object
-  final offsets = <PdfXref>[];
+  /// Document root point
+  final params = PdfDict();
 
-  /// Add a cross reference element to the set
-  void add(PdfXref xref) {
-    offsets.add(xref);
-  }
+  /// List of objects to write
+  final objects = <PdfObjectBase>{};
+
+  /// Contains the offset of each objects
+  final _offsets = <PdfXref>[];
 
   /// Writes a block of references to the Pdf file
   void _writeBlock(PdfStream s, int firstId, List<PdfXref> block) {
@@ -117,26 +119,109 @@ class PdfXrefTable extends PdfDataType {
   }
 
   @override
-  void output(PdfObjectBase o, PdfStream s, [int? indent]) {}
+  void output(PdfObjectBase o, PdfStream s, [int? indent]) {
+    String v;
+    switch (o.version) {
+      case PdfVersion.pdf_1_4:
+        v = '1.4';
+        break;
+      case PdfVersion.pdf_1_5:
+        v = '1.5';
+        break;
+    }
+
+    s.putString('%PDF-$v\n');
+    s.putBytes(const <int>[0x25, 0xC2, 0xA5, 0xC2, 0xB1, 0xC3, 0xAB, 0x0A]);
+    assert(() {
+      if (o.verbose) {
+        setInsertion(s);
+        startStopwatch();
+        debugFill('Verbose dart_pdf');
+        debugFill('Producer https://github.com/DavBfr/dart_pdf');
+        debugFill('Creation date: ${DateTime.now()}');
+      }
+      return true;
+    }());
+
+    for (final ob in objects) {
+      assert(() {
+        if (ob.verbose) {
+          ob.setInsertion(s, 150);
+          ob.startStopwatch();
+        }
+        return true;
+      }());
+      _offsets.add(PdfXref(ob.objser, s.offset, generation: ob.objgen));
+      ob.output(s);
+      assert(() {
+        if (ob.verbose) {
+          ob.stopStopwatch();
+          ob.debugFill(
+              'Creation time: ${ob.elapsedStopwatch / Duration.microsecondsPerSecond} seconds');
+          ob.writeDebug(s);
+        }
+        return true;
+      }());
+    }
+
+    final int xrefOffset;
+
+    params['/Root'] = o.ref();
+
+    switch (o.version) {
+      case PdfVersion.pdf_1_4:
+        xrefOffset = outputLegacy(o, s);
+        break;
+      case PdfVersion.pdf_1_5:
+        xrefOffset = outputCompressed(o, s);
+        break;
+    }
+
+    assert(() {
+      if (o.verbose) {
+        s.putComment('');
+        s.putComment('-' * 78);
+        s.putComment('$runtimeType');
+      }
+      return true;
+    }());
+
+    // the reference to the xref object
+    s.putString('startxref\n$xrefOffset\n%%EOF\n');
+
+    assert(() {
+      if (o.verbose) {
+        stopStopwatch();
+        debugFill(
+            'Creation time: ${elapsedStopwatch / Duration.microsecondsPerSecond} seconds');
+        debugFill('File size: ${s.offset} bytes');
+        // debugFill('Pages: ${rootID!.pdfDocument.pdfPageList.pages.length}');
+        debugFill('Objects: ${objects.length}');
+        writeDebug(s);
+      }
+      return true;
+    }());
+  }
 
   @override
   String toString() {
     final s = StringBuffer();
-    for (final x in offsets) {
+    for (final x in _offsets) {
       s.writeln('  $x');
     }
     return s.toString();
   }
 
-  int outputLegacy(PdfObjectBase object, PdfStream s, PdfDict params) {
+  int outputLegacy(PdfObjectBase o, PdfStream s) {
     // Now scan through the offsets list. They should be in sequence.
-    offsets.sort((a, b) => a.id.compareTo(b.id));
+    _offsets.sort((a, b) => a.id.compareTo(b.id));
+    final size = _offsets.last.id + 1;
 
     assert(() {
-      if (object.verbose) {
+      if (o.verbose) {
         s.putComment('');
         s.putComment('-' * 78);
-        s.putComment('$runtimeType ${object.version.name}\n$this');
+        s.putComment('$runtimeType ${o.version.name}\n$this');
       }
       return true;
     }());
@@ -156,7 +241,7 @@ class PdfXrefTable extends PdfDataType {
     final objOffset = s.offset;
     s.putString('xref\n');
 
-    for (final x in offsets) {
+    for (final x in _offsets) {
       // check to see if block is in range
       if (x.id != (lastId + 1)) {
         // no, so write this block, and reset
@@ -175,31 +260,33 @@ class PdfXrefTable extends PdfDataType {
 
     // the trailer object
     assert(() {
-      if (object.verbose) {
+      if (o.verbose) {
         s.putComment('');
       }
       return true;
     }());
     s.putString('trailer\n');
-    params.output(object, s, object.verbose ? 0 : null);
+    params['/Size'] = PdfNum(size);
+    params.output(o, s, o.verbose ? 0 : null);
     s.putByte(0x0a);
 
     return objOffset;
   }
 
   /// Output a compressed cross-reference table
-  int outputCompressed(PdfObjectBase object, PdfStream s, PdfDict params) {
+  int outputCompressed(PdfObjectBase o, PdfStream s) {
     final offset = s.offset;
 
     // Sort all references
-    offsets.sort((a, b) => a.id.compareTo(b.id));
+    _offsets.sort((a, b) => a.id.compareTo(b.id));
 
     // Write this object too
-    final id = offsets.last.id + 1;
-    offsets.add(PdfXref(id, offset));
+    final id = _offsets.last.id + 1;
+    final size = id + 1;
+    _offsets.add(PdfXref(id, offset));
 
     params['/Type'] = const PdfName('/XRef');
-    params['/Size'] = PdfNum(id + 1);
+    params['/Size'] = PdfNum(size);
 
     var firstId = 0; // First id in block
     var lastId = 0; // The last id used
@@ -208,7 +295,7 @@ class PdfXrefTable extends PdfDataType {
     // We need block 0 to exist
     blocks.add(firstId);
 
-    for (final x in offsets) {
+    for (final x in _offsets) {
       // check to see if block is in range
       if (x.id != (lastId + 1)) {
         // no, so store this block, and reset
@@ -220,7 +307,7 @@ class PdfXrefTable extends PdfDataType {
     }
     blocks.add(lastId - firstId + 1);
 
-    if (!(blocks.length == 2 && blocks[0] == 0 && blocks[1] == id + 1)) {
+    if (!(blocks.length == 2 && blocks[0] == 0 && blocks[1] == size)) {
       params['/Index'] = PdfArray.fromNum(blocks);
     }
 
@@ -229,21 +316,21 @@ class PdfXrefTable extends PdfDataType {
     params['/W'] = PdfArray.fromNum(w);
     final wl = w.reduce((a, b) => a + b);
 
-    final o = ByteData((offsets.length + 1) * wl);
+    final binOffsets = ByteData((_offsets.length + 1) * wl);
     var ofs = 0;
     // Write offset zero, all zeros
     ofs += wl;
 
-    for (final x in offsets) {
-      ofs = x._compressedRef(o, ofs, w);
+    for (final x in _offsets) {
+      ofs = x._compressedRef(binOffsets, ofs, w);
     }
 
     // Write the object
     assert(() {
-      if (object.verbose) {
+      if (o.verbose) {
         s.putComment('');
         s.putComment('-' * 78);
-        s.putComment('$runtimeType ${object.version.name}\n$this');
+        s.putComment('$runtimeType ${o.version.name}\n$this');
       }
       return true;
     }());
@@ -253,13 +340,13 @@ class PdfXrefTable extends PdfDataType {
     s.putString('$id 0 obj\n');
 
     PdfDictStream(
-      data: o.buffer.asUint8List(),
+      data: binOffsets.buffer.asUint8List(),
       isBinary: false,
       encrypt: false,
       values: params.values,
-    ).output(object, s, object.verbose ? 0 : null);
+    ).output(o, s, o.verbose ? 0 : null);
 
-    s.putString('endobj\n');
+    s.putString('\nendobj\n');
     return objOffset;
   }
 }

@@ -19,26 +19,24 @@ import 'package:meta/meta.dart';
 import '../document.dart';
 import '../format/base.dart';
 import '../format/object_base.dart';
-import '../format/stream.dart';
-import 'diagnostic.dart';
 
 /// Base Object used in the PDF file
-abstract class PdfObject<T extends PdfDataType> extends PdfObjectBase
-    with PdfDiagnostic {
+abstract class PdfObject<T extends PdfDataType> extends PdfObjectBase<T> {
   /// This is usually called by extensors to this class, and sets the
   /// Pdf Object Type
   PdfObject(
     this.pdfDocument, {
-    required this.params,
+    required T params,
     int objgen = 0,
     int? objser,
-  }) : super(objser: objser ?? pdfDocument.genSerial(), objgen: objgen) {
+  }) : super(
+          objser: objser ?? pdfDocument.genSerial(),
+          objgen: objgen,
+          params: params,
+        ) {
     pdfDocument.objects.add(this);
   }
 
-  /// This is the object parameters.
-  final T params;
-
   /// This allows any Pdf object to refer to the document being constructed.
   final PdfDocument pdfDocument;
 
@@ -56,35 +54,10 @@ abstract class PdfObject<T extends PdfDataType> extends PdfObjectBase
   @override
   PdfVersion get version => pdfDocument.version;
 
-  /// Writes the object to the output stream.
-  void write(PdfStream os) {
-    prepare();
-    _writeStart(os);
-    writeContent(os);
-    _writeEnd(os);
-  }
-
   /// Prepare the object to be written to the stream
   @mustCallSuper
   void prepare() {}
 
-  /// The write method should call this before writing anything to the
-  /// OutputStream. This will send the standard header for each object.
-  void _writeStart(PdfStream os) {
-    os.putString('$objser $objgen obj\n');
-  }
-
-  void writeContent(PdfStream os) {
-    params.output(this, os, verbose ? 0 : null);
-    os.putByte(0x0a);
-  }
-
-  /// The write method should call this after writing anything to the
-  /// OutputStream. This will send the standard footer for each object.
-  void _writeEnd(PdfStream os) {
-    os.putString('endobj\n');
-  }
-
   @override
   String toString() => '$runtimeType $params';
 }

@@ -36,10 +36,10 @@ class PdfObjectDict extends PdfObject<PdfDict> {
   }
 
   @override
-  void writeContent(PdfStream os) {
+  void writeContent(PdfStream s) {
     if (params.isNotEmpty) {
-      params.output(this, os, pdfDocument.verbose ? 0 : null);
-      os.putByte(0x0a);
+      params.output(this, s, pdfDocument.verbose ? 0 : null);
+      s.putByte(0x0a);
     }
   }
 }

@@ -35,11 +35,12 @@ class PdfObjectStream extends PdfObjectDict {
   final bool isBinary;
 
   @override
-  void writeContent(PdfStream os) {
+  void writeContent(PdfStream s) {
     PdfDictStream.values(
       isBinary: isBinary,
       values: params.values,
       data: buf.output(),
-    ).output(this, os, pdfDocument.verbose ? 0 : null);
+    ).output(this, s, pdfDocument.verbose ? 0 : null);
+    s.putByte(0x0a);
   }
 }

@@ -82,12 +82,12 @@ class PdfSignature extends PdfObjectDict {
   int? _offsetEnd;
 
   @override
-  void write(PdfStream os) {
+  void output(PdfStream s) {
     value.preSign(this, params);
 
-    _offsetStart = os.offset + '$objser $objgen obj\n'.length;
-    super.write(os);
-    _offsetEnd = os.offset;
+    _offsetStart = s.offset + '$objser $objgen obj\n'.length;
+    super.output(s);
+    _offsetEnd = s.offset;
   }
 
   Future<void> writeSignature(PdfStream os) async {

-/*
- * Copyright (C) 2017, David PHAM-VAN <dev.nfet.net@gmail.com>
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-import 'format/array.dart';
-import 'format/dict.dart';
-import 'format/num.dart';
-import 'format/object_base.dart';
-import 'format/stream.dart';
-import 'format/string.dart';
-import 'format/xref.dart';
-import 'obj/catalog.dart';
-import 'obj/diagnostic.dart';
-import 'obj/encryption.dart';
-import 'obj/info.dart';
-import 'obj/object.dart';
-import 'obj/signature.dart';
-
-/// PDF document writer
-class PdfOutput with PdfDiagnostic {
-  /// This creates a Pdf [PdfStream]
-  PdfOutput(this.os, this.version, this.verbose) {
-    String v;
-    switch (version) {
-      case PdfVersion.pdf_1_4:
-        v = '1.4';
-        break;
-      case PdfVersion.pdf_1_5:
-        v = '1.5';
-        break;
-    }
-
-    os.putString('%PDF-$v\n');
-    os.putBytes(const <int>[0x25, 0xC2, 0xA5, 0xC2, 0xB1, 0xC3, 0xAB, 0x0A]);
-    assert(() {
-      if (verbose) {
-        setInsertion(os);
-        startStopwatch();
-        debugFill('Verbose dart_pdf');
-        debugFill('Producer https://github.com/DavBfr/dart_pdf');
-        debugFill('Creation date: ${DateTime.now()}');
-      }
-      return true;
-    }());
-  }
-
-  /// Pdf version to output
-  final PdfVersion version;
-
-  /// This is the actual [PdfStream] used to write to.
-  final PdfStream os;
-
-  /// Cross reference table
-  final xref = PdfXrefTable();
-
-  /// This is used to track the /Root object (catalog)
-  PdfCatalog? rootID;
-
-  /// This is used to track the /Info object (info)
-  PdfInfo? infoID;
-
-  /// This is used to track the /Encrypt object (encryption)
-  PdfEncryption? encryptID;
-
-  /// This is used to track the /Sign object (signature)
-  PdfSignature? signatureID;
-
-  /// Generate a compressed cross reference table
-  bool get isCompressed => version.index > PdfVersion.pdf_1_4.index;
-
-  /// Verbose output
-  final bool verbose;
-
-  /// This method writes a [PdfObject] to the stream.
-  void write(PdfObject ob) {
-    // Check the object to see if it's one that is needed later
-    if (ob is PdfCatalog) {
-      rootID = ob;
-    } else if (ob is PdfInfo) {
-      infoID = ob;
-    } else if (ob is PdfEncryption) {
-      encryptID = ob;
-    } else if (ob is PdfSignature) {
-      assert(signatureID == null, 'Only one document signature is allowed');
-      signatureID = ob;
-    }
-
-    assert(() {
-      if (verbose) {
-        ob.setInsertion(os);
-        ob.startStopwatch();
-      }
-      return true;
-    }());
-    xref.add(PdfXref(ob.objser, os.offset, generation: ob.objgen));
-    ob.write(os);
-    assert(() {
-      if (verbose) {
-        ob.stopStopwatch();
-        ob.debugFill(
-            'Creation time: ${ob.elapsedStopwatch / Duration.microsecondsPerSecond} seconds');
-        ob.writeDebug(os);
-      }
-      return true;
-    }());
-  }
-
-  /// This closes the Stream, writing the xref table
-  Future<void> close() async {
-    if (rootID == null) {
-      throw Exception('Root object is not present in document');
-    }
-
-    final params = PdfDict();
-
-    // the number of entries (REQUIRED)
-    params['/Size'] = PdfNum(rootID!.pdfDocument.objser);
-
-    // the /Root catalog indirect reference (REQUIRED)
-    params['/Root'] = rootID!.ref();
-    final id = PdfString(rootID!.pdfDocument.documentID,
-        format: PdfStringFormat.binary, encrypted: false);
-    params['/ID'] = PdfArray([id, id]);
-
-    // the /Info reference (OPTIONAL)
-    if (infoID != null) {
-      params['/Info'] = infoID!.ref();
-    }
-
-    // the /Encrypt reference (OPTIONAL)
-    if (encryptID != null) {
-      params['/Encrypt'] = encryptID!.ref();
-    }
-
-    if (rootID!.pdfDocument.prev != null) {
-      params['/Prev'] = PdfNum(rootID!.pdfDocument.prev!.xrefOffset);
-    }
-
-    final _xref = isCompressed
-        ? xref.outputCompressed(rootID!, os, params)
-        : xref.outputLegacy(rootID!, os, params);
-
-    assert(() {
-      if (verbose) {
-        os.putComment('');
-        os.putComment('-' * 78);
-        os.putComment('$runtimeType');
-      }
-      return true;
-    }());
-
-    // the reference to the xref object
-    os.putString('startxref\n$_xref\n%%EOF\n');
-
-    assert(() {
-      if (verbose) {
-        stopStopwatch();
-        debugFill(
-            'Creation time: ${elapsedStopwatch / Duration.microsecondsPerSecond} seconds');
-        debugFill('File size: ${os.offset} bytes');
-        debugFill('Pages: ${rootID!.pdfDocument.pdfPageList.pages.length}');
-        debugFill('Objects: ${xref.offsets.length}');
-        writeDebug(os);
-      }
-      return true;
-    }());
-
-    if (signatureID != null) {
-      await signatureID!.writeSignature(os);
-    }
-  }
-}

@@ -18,6 +18,7 @@ export 'pdf/format/array.dart';
 export 'pdf/format/ascii85.dart';
 export 'pdf/format/base.dart';
 export 'pdf/format/bool.dart';
+export 'pdf/format/diagnostic.dart';
 export 'pdf/format/dict.dart';
 export 'pdf/format/dict_stream.dart';
 export 'pdf/format/indirect.dart';

@@ -17,78 +17,74 @@
 import 'dart:convert';
 import 'dart:io';
 
+import 'package:pdf/pdf.dart';
 import 'package:pdf/src/priv.dart';
 import 'package:test/test.dart';
 
-class BasicObject extends PdfObjectBase {
-  const BasicObject(int objser) : super(objser: objser);
+class BasicObject<T extends PdfDataType> extends PdfObjectBase<T> {
+  BasicObject({required super.objser, required super.params});
 
   @override
   bool get verbose => true;
 
-  void write(PdfStream os, PdfDataType value) {
-    os.putString('$objser $objgen obj\n');
-    value.output(this, os, verbose ? 0 : null);
-    os.putByte(0x0a);
-    os.putString('endobj\n');
-  }
+  @override
+  PdfVersion get version => PdfVersion.pdf_1_4;
+
+  @override
+  DeflateCallback? get deflate => zlib.encode;
 }
 
 void main() {
   test('Pdf Minimal', () async {
-    final pages = PdfDict({
-      '/Type': const PdfName('/Pages'),
-      '/Count': const PdfNum(1),
-    });
-
-    final page = PdfDict({
-      '/Type': const PdfName('/Page'),
-      '/Parent': const PdfIndirect(2, 0),
-      '/MediaBox': PdfArray.fromNum([0, 0, 595.27559, 841.88976]),
-      '/Resources': PdfDict({
-        '/ProcSet': PdfArray([
-          const PdfName('/PDF'),
-        ]),
-      }),
-      '/Contents': const PdfIndirect(4, 0),
-    });
-
-    final content = PdfDictStream(
-      data: latin1.encode('30 811.88976 m 200 641.88976 l S'),
-    );
-
-    pages['/Kids'] = PdfArray([const PdfIndirect(3, 0)]);
-
-    final catalog = PdfDict({
-      '/Type': const PdfName('/Catalog'),
-      '/Pages': const PdfIndirect(2, 0),
-    });
+    var objser = 1;
 
-    final os = PdfStream();
+    final pages = BasicObject(
+        objser: objser++,
+        params: PdfDict({
+          '/Type': const PdfName('/Pages'),
+          '/Count': const PdfNum(1),
+        }));
 
-    final xref = PdfXrefTable();
+    final content = BasicObject(
+        objser: objser++,
+        params: PdfDictStream(
+          data: latin1.encode('30 811.88976 m 200 641.88976 l S'),
+        ));
+
+    final page = BasicObject(
+        objser: objser++,
+        params: PdfDict({
+          '/Type': const PdfName('/Page'),
+          '/Parent': pages.ref(),
+          '/MediaBox': PdfArray.fromNum([0, 0, 595.27559, 841.88976]),
+          '/Resources': PdfDict({
+            '/ProcSet': PdfArray([
+              const PdfName('/PDF'),
+            ]),
+          }),
+          '/Contents': content.ref(),
+        }));
+
+    pages.params['/Kids'] = PdfArray([page.ref()]);
 
-    os.putString('%PDF-1.4\n');
-    os.putBytes(const <int>[0x25, 0xC2, 0xA5, 0xC2, 0xB1, 0xC3, 0xAB, 0x0A]);
-
-    xref.add(PdfXref(1, os.offset));
-    final cat = const BasicObject(1)..write(os, catalog);
-    xref.add(PdfXref(2, os.offset));
-    const BasicObject(2).write(os, pages);
-    xref.add(PdfXref(3, os.offset));
-    const BasicObject(3).write(os, page);
-    xref.add(PdfXref(4, os.offset));
-    const BasicObject(4).write(os, content);
-
-    final xrefOffset = xref.outputLegacy(
-        cat,
-        os,
-        PdfDict({
-          '/Size': PdfNum(xref.offsets.length + 1),
-          '/Root': const PdfIndirect(1, 0),
+    final catalog = BasicObject(
+        objser: objser++,
+        params: PdfDict({
+          '/Type': const PdfName('/Catalog'),
+          '/Pages': pages.ref(),
         }));
 
-    os.putString('startxref\n$xrefOffset\n%%EOF\n');
+    final os = PdfStream();
+
+    final xref = PdfXrefTable();
+    xref.objects.addAll([
+      catalog,
+      pages,
+      page,
+      content,
+    ]);
+
+    xref.output(catalog, os);
 
     final file = File('minimal.pdf');
     await file.writeAsBytes(os.output());