Migrate app to null safety

app/lib/pages/home_page.dart

@@ -23,7 +23,7 @@ class HomePage extends StatefulWidget {
 }
 
 class _HomePageState extends State<HomePage> {
-  QuillController _controller;
+  QuillController? _controller;
   final FocusNode _focusNode = FocusNode();
 
   @override
@@ -75,15 +75,15 @@ class _HomePageState extends State<HomePage> {
         focusNode: FocusNode(),
         onKey: (RawKeyEvent event) {
           if (event.data.isControlPressed && event.character == 'b') {
-            if (_controller
+            if (_controller!
                 .getSelectionStyle()
                 .attributes
                 .keys
                 .contains("bold")) {
-              _controller
+              _controller!
                   .formatSelection(Attribute.clone(Attribute.bold, null));
             } else {
-              _controller.formatSelection(Attribute.bold);
+              _controller!.formatSelection(Attribute.bold);
               print("not bold");
             }
           }
@@ -104,7 +104,7 @@ class _HomePageState extends State<HomePage> {
               color: Colors.white,
               padding: const EdgeInsets.only(left: 16.0, right: 16.0),
               child: QuillEditor(
-                controller: _controller,
+                controller: _controller!,
                 scrollController: ScrollController(),
                 scrollable: true,
                 focusNode: _focusNode,
@@ -135,12 +135,12 @@ class _HomePageState extends State<HomePage> {
                   child: Container(
                   padding: EdgeInsets.symmetric(vertical: 16, horizontal: 8),
                   child: QuillToolbar.basic(
-                      controller: _controller,
+                      controller: _controller!,
                       onImagePickCallback: _onImagePickCallback),
                 ))
               : Container(
                   child: QuillToolbar.basic(
-                      controller: _controller,
+                      controller: _controller!,
                       onImagePickCallback: _onImagePickCallback),
                 ),
         ],
@@ -151,7 +151,6 @@ class _HomePageState extends State<HomePage> {
   // Renders the image picked by imagePicker from local file storage
   // You can also upload the picked image to any server (eg : AWS s3 or Firebase) and then return the uploaded image URL
   Future<String> _onImagePickCallback(File file) async {
-    if (file == null) return null;
     // Copies the picked file from temporary cache to applications directory
     Directory appDocDir = await getApplicationDocumentsDirectory();
     File copiedFile =

app/lib/pages/read_only_page.dart

@@ -27,7 +27,7 @@ class _ReadOnlyPageState extends State<ReadOnlyPage> {
     );
   }
 
-  Widget _buildContent(BuildContext context, QuillController controller) {
+  Widget _buildContent(BuildContext context, QuillController? controller) {
     return Padding(
       padding: const EdgeInsets.all(8.0),
       child: Container(
@@ -36,7 +36,7 @@ class _ReadOnlyPageState extends State<ReadOnlyPage> {
           border: Border.all(color: Colors.grey.shade200),
         ),
         child: QuillEditor(
-          controller: controller,
+          controller: controller!,
           scrollController: ScrollController(),
           scrollable: true,
           focusNode: _focusNode,

app/lib/widgets/demo_scaffold.dart

@@ -7,21 +7,21 @@ import 'package:flutter_quill/widgets/controller.dart';
 import 'package:flutter_quill/widgets/toolbar.dart';
 
 typedef DemoContentBuilder = Widget Function(
-    BuildContext context, QuillController controller);
+    BuildContext context, QuillController? controller);
 
 // Common scaffold for all examples.
 class DemoScaffold extends StatefulWidget {
   /// Filename of the document to load into the editor.
   final String documentFilename;
   final DemoContentBuilder builder;
-  final List<Widget> actions;
-  final Widget floatingActionButton;
+  final List<Widget>? actions;
+  final Widget? floatingActionButton;
   final bool showToolbar;
 
   const DemoScaffold({
-    Key key,
-    @required this.documentFilename,
-    @required this.builder,
+    Key? key,
+    required this.documentFilename,
+    required this.builder,
     this.actions,
     this.showToolbar = true,
     this.floatingActionButton,
@@ -33,7 +33,7 @@ class DemoScaffold extends StatefulWidget {
 
 class _DemoScaffoldState extends State<DemoScaffold> {
   final _scaffoldKey = GlobalKey<ScaffoldState>();
-  QuillController _controller;
+  QuillController? _controller;
 
   bool _loading = false;
 
@@ -92,7 +92,7 @@ class _DemoScaffoldState extends State<DemoScaffold> {
         ),
         title: _loading || widget.showToolbar == false
             ? null
-            : QuillToolbar.basic(controller: _controller),
+            : QuillToolbar.basic(controller: _controller!),
         actions: actions,
       ),
       floatingActionButton: widget.floatingActionButton,

app/lib/widgets/field.dart

@@ -6,28 +6,28 @@ import 'package:flutter_quill/widgets/editor.dart';
 
 class QuillField extends StatefulWidget {
   final QuillController controller;
-  final FocusNode focusNode;
-  final ScrollController scrollController;
+  final FocusNode? focusNode;
+  final ScrollController? scrollController;
   final bool scrollable;
   final EdgeInsetsGeometry padding;
   final bool autofocus;
   final bool showCursor;
   final bool readOnly;
   final bool enableInteractiveSelection;
-  final double minHeight;
-  final double maxHeight;
+  final double? minHeight;
+  final double? maxHeight;
   final bool expands;
   final TextCapitalization textCapitalization;
   final Brightness keyboardAppearance;
-  final ScrollPhysics scrollPhysics;
-  final ValueChanged<String> onLaunchUrl;
-  final InputDecoration decoration;
-  final Widget toolbar;
-  final EmbedBuilder embedBuilder;
+  final ScrollPhysics? scrollPhysics;
+  final ValueChanged<String>? onLaunchUrl;
+  final InputDecoration? decoration;
+  final Widget? toolbar;
+  final EmbedBuilder? embedBuilder;
 
   QuillField({
-    Key key,
-    @required this.controller,
+    Key? key,
+    required this.controller,
     this.focusNode,
     this.scrollController,
     this.scrollable = true,
@@ -53,28 +53,28 @@ class QuillField extends StatefulWidget {
 }
 
 class _QuillFieldState extends State<QuillField> {
-  bool _focused;
+  late bool _focused;
 
   void _editorFocusChanged() {
     setState(() {
-      _focused = widget.focusNode.hasFocus;
+      _focused = widget.focusNode!.hasFocus;
     });
   }
 
   @override
   void initState() {
     super.initState();
-    _focused = widget.focusNode.hasFocus;
-    widget.focusNode.addListener(_editorFocusChanged);
+    _focused = widget.focusNode!.hasFocus;
+    widget.focusNode!.addListener(_editorFocusChanged);
   }
 
   @override
   void didUpdateWidget(covariant QuillField oldWidget) {
     super.didUpdateWidget(oldWidget);
     if (widget.focusNode != oldWidget.focusNode) {
-      oldWidget.focusNode.removeListener(_editorFocusChanged);
-      widget.focusNode.addListener(_editorFocusChanged);
-      _focused = widget.focusNode.hasFocus;
+      oldWidget.focusNode!.removeListener(_editorFocusChanged);
+      widget.focusNode!.addListener(_editorFocusChanged);
+      _focused = widget.focusNode!.hasFocus;
     }
   }
 
@@ -82,8 +82,8 @@ class _QuillFieldState extends State<QuillField> {
   Widget build(BuildContext context) {
     Widget child = QuillEditor(
       controller: widget.controller,
-      focusNode: widget.focusNode,
-      scrollController: widget.scrollController,
+      focusNode: widget.focusNode!,
+      scrollController: widget.scrollController!,
       scrollable: widget.scrollable,
       padding: widget.padding,
       autoFocus: widget.autofocus,
@@ -97,7 +97,7 @@ class _QuillFieldState extends State<QuillField> {
       keyboardAppearance: widget.keyboardAppearance,
       scrollPhysics: widget.scrollPhysics,
       onLaunchUrl: widget.onLaunchUrl,
-      embedBuilder: widget.embedBuilder,
+      embedBuilder: widget.embedBuilder!,
     );
 
     if (widget.toolbar != null) {
@@ -105,7 +105,7 @@ class _QuillFieldState extends State<QuillField> {
         children: [
           child,
           Visibility(
-            child: widget.toolbar,
+            child: widget.toolbar!,
             visible: _focused,
             maintainSize: true,
             maintainAnimation: true,
@@ -117,11 +117,11 @@ class _QuillFieldState extends State<QuillField> {
 
     return AnimatedBuilder(
       animation:
-          Listenable.merge(<Listenable>[widget.focusNode, widget.controller]),
-      builder: (BuildContext context, Widget child) {
+          Listenable.merge(<Listenable?>[widget.focusNode, widget.controller]),
+      builder: (BuildContext context, Widget? child) {
         return InputDecorator(
           decoration: _getEffectiveDecoration(),
-          isFocused: widget.focusNode.hasFocus,
+          isFocused: widget.focusNode!.hasFocus,
           // TODO: Document should be considered empty of it has single empty line with no styles applied
           isEmpty: widget.controller.document.length == 1,
           child: child,

app/pubspec.lock

@@ -43,27 +43,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.15.0"
-  convert:
-    dependency: transitive
-    description:
-      name: convert
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.1"
-  crypto:
-    dependency: transitive
-    description:
-      name: crypto
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.5"
-  csslib:
-    dependency: transitive
-    description:
-      name: csslib
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.16.2"
   cupertino_icons:
     dependency: "direct main"
     description:
@@ -110,7 +89,7 @@ packages:
       name: flutter_colorpicker
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.5"
+    version: "0.4.0-nullsafety.0"
   flutter_keyboard_visibility:
     dependency: transitive
     description:
@@ -156,13 +135,6 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
-  html:
-    dependency: transitive
-    description:
-      name: html
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.14.0+4"
   http:
     dependency: transitive
     description:
@@ -183,7 +155,7 @@ packages:
       name: image_picker
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.7.2"
+    version: "0.7.2+1"
   image_picker_platform_interface:
     dependency: transitive
     description:
@@ -267,7 +239,7 @@ packages:
       name: photo_view
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.10.3"
+    version: "0.11.1"
   platform:
     dependency: transitive
     description:
@@ -295,14 +267,7 @@ packages:
       name: quiver
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.5"
-  quiver_hashcode:
-    dependency: transitive
-    description:
-      name: quiver_hashcode
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.0"
+    version: "3.0.0"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -342,7 +307,7 @@ packages:
       name: string_validator
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.4"
+    version: "0.2.0-nullsafety.0"
   term_glyph:
     dependency: transitive
     description:
@@ -363,7 +328,7 @@ packages:
       name: tuple
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.3"
+    version: "2.0.0"
   typed_data:
     dependency: transitive
     description:
@@ -371,27 +336,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.3.0"
-  universal_html:
-    dependency: transitive
-    description:
-      name: universal_html
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.2.4"
-  universal_io:
-    dependency: transitive
-    description:
-      name: universal_io
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.2"
-  universal_ui:
-    dependency: transitive
-    description:
-      name: universal_ui
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.0.8"
   url_launcher:
     dependency: transitive
     description:
@@ -455,13 +399,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.2.0"
-  zone_local:
-    dependency: transitive
-    description:
-      name: zone_local
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.1.2"
 sdks:
   dart: ">=2.12.0 <3.0.0"
-  flutter: ">=1.22.0"
+  flutter: ">=1.24.0-10.2.pre"

app/pubspec.yaml

@@ -18,7 +18,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter: