Add unicode support for annotations and info block

@@ -8,6 +8,7 @@
 * Implement drawShape
 * Add support for Jpeg images
 * Fix numeric conversions in graphic operations
+* Add unicode support for annotations and info block
 
 # 1.0.8
 * Fix monospace TTF font loading

@@ -22,6 +22,7 @@ import 'dart:convert';
 import 'dart:typed_data';
 
 import 'package:meta/meta.dart';
+import 'package:utf/utf.dart';
 import 'package:vector_math/vector_math_64.dart';
 
 part 'src/annotation.dart';

@@ -97,7 +97,7 @@ class PdfAnnot extends PdfObject {
 
     // Now the annotation subtypes
     if (subtype == "/Text") {
-      params["/Contents"] = PdfStream.text(content);
+      params["/Contents"] = PdfStream()..putLiteral(content);
     } else if (subtype == "/Link") {
       var dests = List<PdfStream>();
       dests.add(dest.ref());

@@ -96,7 +96,6 @@ class PdfDocument {
     // Now create some standard objects
     pdfPageList = PdfPageList(this);
     catalog = PdfCatalog(this, pdfPageList, pageMode);
-    info = PdfInfo(this);
   }
 
   /// This returns a specific page. It's used mainly when using a

@@ -19,28 +19,43 @@
 part of pdf;
 
 class PdfInfo extends PdfObject {
-  String author;
-  String creator;
-  String title;
-  String subject;
-  String keywords;
+  static const String _libraryName = "https://github.com/DavBfr/dart_pdf";
+  final String author;
+  final String creator;
+  final String title;
+  final String subject;
+  final String keywords;
+  final String producer;
 
   /// @param title Title of this document
   PdfInfo(PdfDocument pdfDocument,
-      {this.title, this.author, this.creator, this.subject, this.keywords})
+      {this.title,
+      this.author,
+      this.creator,
+      this.subject,
+      this.keywords,
+      this.producer})
       : super(pdfDocument, null) {
-    params["/Producer"] = PdfStream.text("dpdf - David PHAM-VAN");
-  }
-
-  /// @param os OutputStream to send the object to
-  @override
-  void _prepare() {
-    super._prepare();
-
-    if (author != null) params["/Author"] = PdfStream.text(author);
-    if (creator != null) params["/Creator"] = PdfStream.text(creator);
-    if (title != null) params["/Title"] = PdfStream.text(title);
-    if (subject != null) params["/Subject"] = PdfStream.text(subject);
-    if (keywords != null) params["/Keywords"] = PdfStream.text(keywords);
+    if (author != null) {
+      params["/Author"] = PdfStream()..putLiteral(author);
+    }
+    if (creator != null) {
+      params["/Creator"] = PdfStream()..putLiteral(creator);
+    }
+    if (title != null) {
+      params["/Title"] = PdfStream()..putLiteral(title);
+    }
+    if (subject != null) {
+      params["/Subject"] = PdfStream()..putLiteral(subject);
+    }
+    if (keywords != null) {
+      params["/Keywords"] = PdfStream()..putLiteral(keywords);
+    }
+    if (producer != null) {
+      params["/Producer"] = PdfStream()
+        ..putLiteral("$producer ($_libraryName)");
+    } else {
+      params["/Producer"] = PdfStream()..putLiteral(_libraryName);
+    }
   }
 }

@@ -60,31 +60,61 @@ class PdfStream {
   static PdfStream num(double d) => PdfStream()..putNum(d);
   static PdfStream intNum(int i) => PdfStream()..putString(i.toString());
 
+  /// Escape special characters
+  /// \ddd Character code ddd (octal)
+  void putTextBytes(List<int> s) {
+    for (var c in s) {
+      switch (c) {
+        case 0x0a: // \n Line feed (LF)
+          _stream.add(0x5c);
+          _stream.add(0x6e);
+          break;
+        case 0x0d: // \r Carriage return (CR)
+          _stream.add(0x5c);
+          _stream.add(0x72);
+          break;
+        case 0x09: // \t Horizontal tab (HT)
+          _stream.add(0x5c);
+          _stream.add(0x74);
+          break;
+        case 0x08: // \b Backspace (BS)
+          _stream.add(0x5c);
+          _stream.add(0x62);
+          break;
+        case 0x0c: // \f Form feed (FF)
+          _stream.add(0x5c);
+          _stream.add(0x66);
+          break;
+        case 0x28: // \( Left parenthesis
+          _stream.add(0x5c);
+          _stream.add(0x28);
+          break;
+        case 0x29: // \) Right parenthesis
+          _stream.add(0x5c);
+          _stream.add(0x29);
+          break;
+        case 0x5c: // \\ Backslash
+          _stream.add(0x5c);
+          _stream.add(0x5c);
+          break;
+        default:
+          _stream.add(c);
+      }
+    }
+  }
+
   void putText(String s) {
-    // Escape special characters
-    //    \n Line feed (LF)
-    //    \r Carriage return (CR)
-    //    \t Horizontal tab (HT)
-    //    \b Backspace (BS)
-    //    \f Form feed (FF)
-    //    \( Left parenthesis
-    //    \) Right parenthesis
-    //    \\ Backslash
-    //    \ddd Character code ddd (octal)
-    s = s
-        .replaceAll('\\', '\\\\')
-        .replaceAll('(', '\\(')
-        .replaceAll(')', '\\)')
-        .replaceAll('\n', '\\n')
-        .replaceAll('\t', '\\t')
-        .replaceAll('\b', '\\b')
-        .replaceAll('\f', '\\f')
-        .replaceAll('\r', '\\r');
-
-    putBytes(latin1.encode('(' + s + ')'));
+    putBytes(latin1.encode('('));
+    putTextBytes(latin1.encode(s));
+    putBytes(latin1.encode(')'));
   }
 
-  static PdfStream text(String s) => PdfStream()..putText(s);
+  void putLiteral(String s) {
+    putBytes(latin1.encode('('));
+    putBytes([0xfe, 0xff]);
+    putTextBytes(encodeUtf16be(s));
+    putBytes(latin1.encode(')'));
+  }
 
   void putBool(bool value) {
     putString(value ? "true" : "false");

@@ -10,6 +10,7 @@ environment:
 dependencies:
   meta: "^1.1.5"
   vector_math: "^2.0.0"
+  utf: "^0.9.0"
 
 dev_dependencies:
   test: any

@@ -12,11 +12,11 @@ void main() {
     img.fillRange(0, img.length - 1, 0x12345678);
 
     var pdf = PdfDocument(deflate: zlib.encode);
-    var i = pdf.info;
-    i.author = "David PHAM-VAN";
-    i.creator = i.author;
-    i.title = "My Title";
-    i.subject = "My Subject";
+    pdf.info = PdfInfo(pdf,
+        author: "David PHAM-VAN",
+        creator: "David PHAM-VAN",
+        title: "My Title",
+        subject: "My Subject");
     var page = PdfPage(pdf, pageFormat: const PdfPageFormat(500.0, 300.0));
 
     var g = page.getGraphics();

@@ -7,11 +7,6 @@ import 'package:test/test.dart';
 void main() {
   test('Pdf', () {
     var pdf = PdfDocument();
-    var i = pdf.info;
-    i.author = "David PHAM-VAN";
-    i.creator = i.author;
-    i.title = "My Title";
-    i.subject = "My Subject";
     var page = PdfPage(pdf, pageFormat: const PdfPageFormat(500.0, 300.0));
 
     var g = page.getGraphics();