Remove dependency to dart:io for web

+# 1.0.5
+* Remove dependency to dart:io
+* Add Contributing
+
 # 1.0.4
 * Updated homepage
 * Update source formatting

@@ -3,7 +3,7 @@ import 'dart:io';
 import 'package:pdf/pdf.dart';
 
 void main() {
-  final pdf = new PDFDocument();
+  final pdf = new PDFDocument(deflate: zlib.encode);
   final page = new PDFPage(pdf, pageFormat: PDFPageFormat.LETTER);
   final g = page.getGraphics();
   final font = new PDFFont(pdf);

@@ -19,7 +19,6 @@
 library pdf;
 
 import 'dart:convert';
-import 'dart:io';
 import 'dart:typed_data';
 
 import 'package:meta/meta.dart';

@@ -18,8 +18,8 @@
 
 part of pdf;
 
-class Ascii85Encoder extends Converter<Uint8List, Uint8List> {
-  Uint8List convert(Uint8List input) {
+class Ascii85Encoder extends Converter<List<int>, List<int>> {
+  List<int> convert(List<int> input) {
     Uint8List buffer = new Uint8List(_maxEncodedLen(input.length) + 2);
 
     var b = 0;

@@ -37,6 +37,8 @@ enum PDFPageMode {
   FULLSCREEN
 }
 
+typedef List<int> DeflateCallback(List<int> data);
+
 /// <p>This class is the base of the PDF generator. A PDFDocument class is
 /// created for a document, and each page, object, annotation,
 /// etc is added to the document.
@@ -66,8 +68,10 @@ class PDFDocument {
   /// It's only used when the document is being written.
   PDFObject defaultOutlineBorder;
 
-  /// True if we will compress the stream in the pdf file
-  final bool deflate;
+  /// Callback to compress the stream in the pdf file.
+  /// Use `deflate: zlib.encode` if using dart:io
+  /// No compression by default
+  final DeflateCallback deflate;
 
   /// <p>
   /// These map the page modes just defined to the pagemodes setting of PDF.
@@ -88,7 +92,7 @@ class PDFDocument {
   /// <p>This creates a PDF document</p>
   /// @param pagemode an int, determines how the document will present itself to
   /// the viewer when it first opens.
-  PDFDocument({PDFPageMode pageMode = PDFPageMode.NONE, this.deflate = true}) {
+  PDFDocument({PDFPageMode pageMode = PDFPageMode.NONE, this.deflate}) {
     _objser = 1;
 
     // Now create some standard objects
@@ -141,7 +145,7 @@ class PDFDocument {
     pos.close();
   }
 
-  Uint8List save() {
+  List<int> save() {
     PDFStream os = new PDFStream();
     write(os);
     return os.output();

@@ -34,15 +34,14 @@ class PDFObjectStream extends PDFObject {
   PDFObjectStream(PDFDocument pdfDocument, {String type, this.isBinary = false})
       : super(pdfDocument, type);
 
-  Uint8List _data;
+  List<int> _data;
 
   @override
   void prepare() {
     super.prepare();
 
-    if (pdfDocument.deflate) {
-      var z = new ZLibCodec(level: ZLibOption.maxLevel);
-      _data = z.encode(buf.output());
+    if (pdfDocument.deflate != null) {
+      _data = pdfDocument.deflate(buf.output());
       params["/Filter"] = PDFStream.string("/FlateDecode");
     } else if (isBinary) {
       // This is a Ascii85 stream

@@ -19,18 +19,18 @@
 part of pdf;
 
 class PDFStream {
-  final _stream = new BytesBuilder(copy: false);
+  final _stream = List<int>();
 
   void putStream(PDFStream s) {
-    _stream.add(s._stream.toBytes());
+    _stream.addAll(s._stream);
   }
 
   void putString(String s) {
     for (int codeUnit in s.codeUnits) {
       if (codeUnit <= 0x7f) {
-        _stream.addByte(codeUnit);
+        _stream.add(codeUnit);
       } else {
-        _stream.addByte(0x20);
+        _stream.add(0x20);
       }
     }
   }
@@ -39,13 +39,13 @@ class PDFStream {
 
   void putStringUtf16(String s) {
     for (int codeUnit in s.codeUnits) {
-      _stream.addByte(codeUnit & 0xff);
-      _stream.addByte((codeUnit >> 8) & 0xff);
+      _stream.add(codeUnit & 0xff);
+      _stream.add((codeUnit >> 8) & 0xff);
     }
   }
 
   void putBytes(List<int> s) {
-    _stream.add(s);
+    _stream.addAll(s);
   }
 
   void putNum(double d) {
@@ -135,5 +135,5 @@ class PDFStream {
 
   int get offset => _stream.length;
 
-  Uint8List output() => _stream.toBytes();
+  List<int> output() => _stream;
 }

@@ -2,7 +2,7 @@ name: pdf
 author: David PHAM-VAN <dev.nfet.net@gmail.com>
 description: A pdf producer for Dart. It can create pdf files for both web or flutter.
 homepage: https://github.com/DavBfr/dart_pdf/tree/master/pdf
-version: 1.0.4
+version: 1.0.5
 
 environment:
   sdk: ">=1.8.0 <3.0.0"

@@ -8,10 +8,11 @@ import 'package:vector_math/vector_math_64.dart';
 
 void main() {
   test('Pdf', () {
-//    Image img = new Image(10, 10);
-//    img.fill(0x12345678);
+    var img = new Uint32List(10 * 10);
+    print(img.length);
+    img.fillRange(0, img.length - 1, 0x12345678);
 
-    var pdf = new PDFDocument(deflate: false);
+    var pdf = new PDFDocument(deflate: zlib.encode);
     var i = pdf.info;
     i.author = "David PHAM-VAN";
     i.creator = i.author;
@@ -50,8 +51,8 @@ void main() {
     g.drawRect(300.0, 150.0, 50.0, 50.0);
     g.fillPath();
     g.setColor(new PDFColor(0.0, 0.5, 0.0));
-//    var image = new PDFImage(pdf,
-//        image: img.data.buffer.asUint8List(), width: img.width, height: img.height);
+    var image = new PDFImage(pdf,
+        image: img.buffer.asUint8List(), width: 10, height: 10);
     for (var i = 10.0; i < 90.0; i += 5.0) {
       g.saveContext();
       var tm = new Matrix4.identity();
@@ -59,7 +60,7 @@ void main() {
       tm.translate(300.0, -100.0);
       g.setTransform(tm);
       g.drawString(font1, 12.0, "Hello $i", 20.0, 100.0);
-//      g.drawImage(image, 100.0, 100.0, 80.0);
+      g.drawImage(image, 100.0, 100.0);
       g.restoreContext();
     }
 

@@ -5,7 +5,7 @@ import "package:test/test.dart";
 
 void main() {
   test('Pdf1', () {
-    var pdf = new PDFDocument(deflate: false);
+    var pdf = new PDFDocument();
     var page = new PDFPage(pdf, pageFormat: PDFPageFormat.A4);
 
     var g = page.getGraphics();

@@ -6,7 +6,7 @@ import 'package:test/test.dart';
 
 void main() {
   test('Pdf', () {
-    var pdf = new PDFDocument(deflate: false);
+    var pdf = new PDFDocument();
     var i = pdf.info;
     i.author = "David PHAM-VAN";
     i.creator = i.author;

+# 1.0.4
+* Update example for pdf 1.0.5
+* Add Contributing
+
 # 1.0.3
 * Update source formatting
 * Update README

+import 'dart:io';
 import 'dart:ui';
 
 import 'package:flutter/material.dart';
@@ -10,7 +11,7 @@ class MyApp extends StatelessWidget {
   final shareWidget = new GlobalKey();
 
   PDFDocument _generateDocument() {
-    final pdf = new PDFDocument();
+    final pdf = new PDFDocument(deflate: zlib.encode);
     final page = new PDFPage(pdf, pageFormat: PDFPageFormat.A4);
     final g = page.getGraphics();
     final font = new PDFFont(pdf);

@@ -2,7 +2,7 @@ name: printing
 author: David PHAM-VAN <dev.nfet.net@gmail.com>
 description: Plugin that allows Flutter apps to generate and print documents to android or ios compatible printers
 homepage: https://github.com/DavBfr/dart_pdf/tree/master/printing
-version: 1.0.3
+version: 1.0.4
 
 environment:
   sdk: ">=1.19.0 <3.0.0"
@@ -10,7 +10,7 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
-  pdf: "^1.0.3"
+  pdf: "^1.0.5"
 
 flutter:
   plugin: