Add imageFromAssetBundle and networkImage

 # Changelog
 
+## 5.0.0-nullsafety.2
+
+- Add imageFromAssetBundle and networkImage
+
 ## 5.0.0-nullsafety.1
 
 - Fix PdfPreview default locale

@@ -46,16 +46,15 @@ doc.addPage(pw.Page(
       pageFormat: PdfPageFormat.a4,
       build: (pw.Context context) {
         return pw.Center(
-          child: pw.Text("Hello World"),
+          child: pw.Text('Hello World'),
         ); // Center
       })); // Page
 ```
 
-To load an image from an ImageProvider:
+To load an image from a Flutter asset:
 
 ```dart
-const imageProvider = const AssetImage('assets/image.png');
-final image = await flutterImageProvider(imageProvider);
+final image = await imageFromAssetBundle('assets/image.png');
 
 doc.addPage(pw.Page(
     build: (pw.Context context) {
@@ -68,8 +67,7 @@ doc.addPage(pw.Page(
 To use a TrueType font from a flutter bundle:
 
 ```dart
-final font = await rootBundle.load("assets/open-sans.ttf");
-final ttf = pw.Font.ttf(font);
+final ttf = await fontFromAssetBundle('assets/open-sans.ttf');
 
 doc.addPage(pw.Page(
     build: (pw.Context context) {
@@ -83,7 +81,7 @@ To save the pdf file using the [path_provider](https://pub.dev/packages/path_pro
 
 ```dart
 final output = await getTemporaryDirectory();
-final file = File("${output.path}/example.pdf");
+final file = File('${output.path}/example.pdf');
 await file.writeAsBytes(await doc.save());
 ```
 

@@ -15,10 +15,13 @@
  */
 
 import 'dart:async';
+import 'dart:io';
+import 'dart:typed_data';
 import 'dart:ui' as ui;
 
 import 'package:flutter/rendering.dart' as rdr;
 import 'package:flutter/services.dart';
+import 'package:pdf/pdf.dart';
 import 'package:pdf/widgets.dart';
 
 /// Loads an image from a Flutter [ImageProvider]
@@ -63,7 +66,108 @@ Future<ImageProvider> flutterImageProvider(
 
 /// Loads a font from an asset bundle key. If used multiple times with the same font name,
 /// it will be included multiple times in the pdf file
-Future<TtfFont> fontFromAssetBundle(String key, AssetBundle bundle) async {
+Future<TtfFont> fontFromAssetBundle(String key, [AssetBundle? bundle]) async {
+  bundle ??= rootBundle;
   final data = await bundle.load(key);
   return TtfFont(data);
 }
+
+/// Load an image from an asset bundle key.
+Future<ImageProvider> imageFromAssetBundle(String key,
+    [AssetBundle? bundle]) async {
+  bundle ??= rootBundle;
+  final data = await bundle.load(key);
+  return MemoryImage(data.buffer.asUint8List());
+}
+
+final HttpClient _sharedHttpClient = HttpClient();
+
+/// Store network images in a cache
+abstract class PdfBaseImageCache {
+  /// Create a network image cache
+  const PdfBaseImageCache();
+
+  /// The default cache used when none specified
+  static final defaultCache = PdfMemoryImageCache();
+
+  /// Add an image to the cache
+  Future<void> add(String key, Uint8List bytes);
+
+  /// Retrieve an image from the cache
+  Future<Uint8List?> get(String key);
+
+  /// Does the cache contains this image?
+  Future<bool> contains(String key);
+
+  /// Remove an image from the cache
+  Future<void> remove(String key);
+
+  /// Clear the cache
+  Future<void> clear();
+}
+
+/// Memory image cache
+class PdfMemoryImageCache extends PdfBaseImageCache {
+  /// Create a memory image cache
+  PdfMemoryImageCache();
+
+  final _imageCache = <String, Uint8List>{};
+
+  @override
+  Future<void> add(String key, Uint8List bytes) async {
+    _imageCache[key] = bytes;
+  }
+
+  @override
+  Future<Uint8List?> get(String key) async {
+    return _imageCache[key];
+  }
+
+  @override
+  Future<void> clear() async {
+    _imageCache.clear();
+  }
+
+  @override
+  Future<bool> contains(String key) async {
+    return _imageCache.containsKey(key);
+  }
+
+  @override
+  Future<void> remove(String key) async {
+    _imageCache.remove(key);
+  }
+}
+
+/// Download an image from the network.
+Future<ImageProvider> networkImage(
+  String url, {
+  bool cache = true,
+  Map<String, String>? headers,
+  PdfImageOrientation? orientation,
+  double? dpi,
+  PdfBaseImageCache? imageCache,
+}) async {
+  imageCache ??= PdfBaseImageCache.defaultCache;
+
+  if (cache && await imageCache.contains(url)) {
+    return MemoryImage((await imageCache.get(url))!,
+        orientation: orientation, dpi: dpi);
+  }
+
+  final request = await _sharedHttpClient.getUrl(Uri.parse(url));
+  headers?.forEach((String name, String value) {
+    request.headers.add(name, value);
+  });
+  final response = await request.close();
+  final builder = await response.fold(
+      BytesBuilder(), (BytesBuilder b, List<int> d) => b..add(d));
+  final List<int> data = builder.takeBytes();
+  final bytes = Uint8List.fromList(data);
+
+  if (cache) {
+    await imageCache.add(url, bytes);
+  }
+
+  return MemoryImage(bytes, orientation: orientation, dpi: dpi);
+}

@@ -4,7 +4,7 @@ description: Plugin that allows Flutter apps to generate and print documents to
 homepage: https://github.com/DavBfr/dart_pdf/tree/master/printing
 repository: https://github.com/DavBfr/dart_pdf
 issue_tracker: https://github.com/DavBfr/dart_pdf/issues
-version: 5.0.0-nullsafety.1
+version: 5.0.0-nullsafety.2
 
 environment:
   sdk: ">=2.12.0-0 <3.0.0"