Merge branch 'master' into fix2

.github/ISSUE_TEMPLATE/issue-template.md

@@ -11,6 +11,6 @@ My issue is about [Web]
 My issue is about [Mobile]
 My issue is about [Desktop]
 
-I have tried running `example` directory successfully before creating an issue here AND it is NOT a stupid question.
+I have tried running `example` directory successfully before creating an issue here.
 
 Please note that we are using stable channel. If you are using beta or master channel, those are not supported.

CHANGELOG.md

@@ -1,3 +1,6 @@
+## [1.1.8]
+* Fix height of empty line bug.
+
 ## [1.1.7]
 * Fix text selection in read-only mode.
 

analysis_options.yaml

@@ -3,13 +3,33 @@ include: package:pedantic/analysis_options.yaml
 analyzer:
   errors:
     undefined_prefixed_name: ignore
-    omit_local_variable_types: ignore
     unsafe_html: ignore
 linter:
   rules:
+    - always_declare_return_types
     - always_put_required_named_parameters_first
+    - annotate_overrides
+    - avoid_empty_else
+    - avoid_escaping_inner_quotes
     - avoid_print
     - avoid_redundant_argument_values
+    - avoid_types_on_closure_parameters
+    - avoid_void_async
+    - cascade_invocations
+    - directives_ordering
+    - omit_local_variable_types
     - prefer_const_constructors
     - prefer_const_constructors_in_immutables
+    - prefer_const_declarations
+    - prefer_final_fields
+    - prefer_final_in_for_each
+    - prefer_final_locals
+    - prefer_initializing_formals
+    - prefer_int_literals
+    - prefer_interpolation_to_compose_strings
+    - prefer_relative_imports
+    - prefer_single_quotes
+    - sort_constructors_first
+    - sort_unnamed_constructors_first
     - unnecessary_parenthesis
+    - unnecessary_string_interpolations

example/lib/pages/home_page.dart

@@ -2,7 +2,6 @@ import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
-import 'package:app/universal_ui/universal_ui.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
@@ -16,6 +15,7 @@ import 'package:path/path.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:tuple/tuple.dart';
 
+import '../universal_ui/universal_ui.dart';
 import 'read_only_page.dart';
 
 class HomePage extends StatefulWidget {
@@ -74,7 +74,7 @@ class _HomePageState extends State<HomePage> {
       ),
       body: RawKeyboardListener(
         focusNode: FocusNode(),
-        onKey: (RawKeyEvent event) {
+        onKey: (event) {
           if (event.data.isControlPressed && event.character == 'b') {
             if (_controller!
                 .getSelectionStyle()
@@ -107,15 +107,15 @@ class _HomePageState extends State<HomePage> {
         customStyles: DefaultStyles(
           h1: DefaultTextBlockStyle(
               const TextStyle(
-                fontSize: 32.0,
+                fontSize: 32,
                 color: Colors.black,
                 height: 1.15,
                 fontWeight: FontWeight.w300,
               ),
-              const Tuple2(16.0, 0.0),
+              const Tuple2(16, 0),
-              const Tuple2(0.0, 0.0),
+              const Tuple2(0, 0),
               null),
-          sizeSmall: const TextStyle(fontSize: 9.0),
+          sizeSmall: const TextStyle(fontSize: 9),
         ));
     if (kIsWeb) {
       quillEditor = QuillEditor(
@@ -131,15 +131,15 @@ class _HomePageState extends State<HomePage> {
           customStyles: DefaultStyles(
             h1: DefaultTextBlockStyle(
                 const TextStyle(
-                  fontSize: 32.0,
+                  fontSize: 32,
                   color: Colors.black,
                   height: 1.15,
                   fontWeight: FontWeight.w300,
                 ),
-                const Tuple2(16.0, 0.0),
+                const Tuple2(16, 0),
-                const Tuple2(0.0, 0.0),
+                const Tuple2(0, 0),
                 null),
-            sizeSmall: const TextStyle(fontSize: 9.0),
+            sizeSmall: const TextStyle(fontSize: 9),
           ),
           embedBuilder: defaultEmbedBuilderWeb);
     }
@@ -151,7 +151,7 @@ class _HomePageState extends State<HomePage> {
             flex: 15,
             child: Container(
               color: Colors.white,
-              padding: const EdgeInsets.only(left: 16.0, right: 16.0),
+              padding: const EdgeInsets.only(left: 16, right: 16),
               child: quillEditor,
             ),
           ),
@@ -178,15 +178,15 @@ class _HomePageState extends State<HomePage> {
   // 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 {
     // Copies the picked file from temporary cache to applications directory
-    Directory appDocDir = await getApplicationDocumentsDirectory();
+    final appDocDir = await getApplicationDocumentsDirectory();
-    File copiedFile =
+    final copiedFile =
         await file.copy('${appDocDir.path}/${basename(file.path)}');
     return copiedFile.path.toString();
   }
 
   Widget _buildMenuBar(BuildContext context) {
-    Size size = MediaQuery.of(context).size;
+    final size = MediaQuery.of(context).size;
-    final itemStyle = const TextStyle(
+    const itemStyle = TextStyle(
       color: Colors.white,
       fontSize: 18,
       fontWeight: FontWeight.bold,
@@ -201,7 +201,7 @@ class _HomePageState extends State<HomePage> {
           endIndent: size.width * 0.1,
         ),
         ListTile(
-          title: Center(child: Text('Read only demo', style: itemStyle)),
+          title: const Center(child: Text('Read only demo', style: itemStyle)),
           dense: true,
           visualDensity: VisualDensity.compact,
           onTap: _readOnly,
@@ -220,7 +220,7 @@ class _HomePageState extends State<HomePage> {
     Navigator.push(
       super.context,
       MaterialPageRoute(
-        builder: (BuildContext context) => ReadOnlyPage(),
+        builder: (context) => ReadOnlyPage(),
       ),
     );
   }

example/lib/pages/read_only_page.dart

@@ -1,9 +1,9 @@
-import 'package:app/universal_ui/universal_ui.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_quill/widgets/controller.dart';
 import 'package:flutter_quill/widgets/editor.dart';
 
+import '../universal_ui/universal_ui.dart';
 import '../widgets/demo_scaffold.dart';
 
 class ReadOnlyPage extends StatefulWidget {
@@ -53,7 +53,7 @@ class _ReadOnlyPageState extends State<ReadOnlyPage> {
           embedBuilder: defaultEmbedBuilderWeb);
     }
     return Padding(
-      padding: const EdgeInsets.all(8.0),
+      padding: const EdgeInsets.all(8),
       child: Container(
         decoration: BoxDecoration(
           color: Colors.white,

example/lib/universal_ui/universal_ui.dart

@@ -28,10 +28,10 @@ var ui = UniversalUI();
 Widget defaultEmbedBuilderWeb(BuildContext context, leaf.Embed node) {
   switch (node.value.type) {
     case 'image':
-      String imageUrl = node.value.data;
+      final String imageUrl = node.value.data;
-      Size size = MediaQuery.of(context).size;
+      final size = MediaQuery.of(context).size;
       UniversalUI().platformViewRegistry.registerViewFactory(
-          imageUrl, (int viewId) => html.ImageElement()..src = imageUrl);
+          imageUrl, (viewId) => html.ImageElement()..src = imageUrl);
       return Padding(
         padding: EdgeInsets.only(
           right: ResponsiveWidget.isMediumScreen(context)

example/lib/widgets/demo_scaffold.dart

@@ -11,13 +11,6 @@ typedef DemoContentBuilder = Widget Function(
 
 // 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 bool showToolbar;
-
   const DemoScaffold({
     required this.documentFilename,
     required this.builder,
@@ -27,6 +20,13 @@ class DemoScaffold extends StatefulWidget {
     Key? key,
   }) : super(key: key);
 
+  /// Filename of the document to load into the editor.
+  final String documentFilename;
+  final DemoContentBuilder builder;
+  final List<Widget>? actions;
+  final Widget? floatingActionButton;
+  final bool showToolbar;
+
   @override
   _DemoScaffoldState createState() => _DemoScaffoldState();
 }

example/test/widget_test.dart

@@ -10,7 +10,7 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:app/main.dart';
 
 void main() {
-  testWidgets('Counter increments smoke test', (WidgetTester tester) async {
+  testWidgets('Counter increments smoke test', (tester) async {
     // Build our app and trigger a frame.
     await tester.pumpWidget(MyApp());
 

lib/models/documents/attribute.dart

@@ -8,12 +8,12 @@ enum AttributeScope {
 }
 
 class Attribute<T> {
+  Attribute(this.key, this.scope, this.value);
+
   final String key;
   final AttributeScope scope;
   final T value;
 
-  Attribute(this.key, this.scope, this.value);
-
   static final Map<String, Attribute> _registry = {
     Attribute.bold.key: Attribute.bold,
     Attribute.italic.key: Attribute.italic,
@@ -164,8 +164,8 @@ class Attribute<T> {
     if (!_registry.containsKey(key)) {
       throw ArgumentError.value(key, 'key "$key" not found.');
     }
-    Attribute origin = _registry[key]!;
+    final origin = _registry[key]!;
-    Attribute attribute = clone(origin, value);
+    final attribute = clone(origin, value);
     return attribute;
   }
 
@@ -177,7 +177,7 @@ class Attribute<T> {
   bool operator ==(Object other) {
     if (identical(this, other)) return true;
     if (other is! Attribute<T>) return false;
-    Attribute<T> typedOther = other;
+    final typedOther = other;
     return key == typedOther.key &&
         scope == typedOther.scope &&
         value == typedOther.value;

lib/models/documents/document.dart

@@ -1,20 +1,32 @@
 import 'dart:async';
 
-import 'package:flutter_quill/models/documents/nodes/block.dart';
-import 'package:flutter_quill/models/documents/nodes/container.dart';
-import 'package:flutter_quill/models/documents/nodes/line.dart';
-import 'package:flutter_quill/models/documents/style.dart';
-import 'package:flutter_quill/models/quill_delta.dart';
 import 'package:tuple/tuple.dart';
 
+import '../quill_delta.dart';
 import '../rules/rule.dart';
 import 'attribute.dart';
 import 'history.dart';
+import 'nodes/block.dart';
+import 'nodes/container.dart';
 import 'nodes/embed.dart';
+import 'nodes/line.dart';
 import 'nodes/node.dart';
+import 'style.dart';
 
 /// The rich text document
 class Document {
+  Document() : _delta = Delta()..insert('\n') {
+    _loadDocument(_delta);
+  }
+
+  Document.fromJson(List data) : _delta = _transform(Delta.fromJson(data)) {
+    _loadDocument(_delta);
+  }
+
+  Document.fromDelta(Delta delta) : _delta = delta {
+    _loadDocument(delta);
+  }
+
   /// The root node of the document tree
   final Root _root = Root();
 
@@ -35,18 +47,6 @@ class Document {
 
   Stream<Tuple3<Delta, Delta, ChangeSource>> get changes => _observer.stream;
 
-  Document() : _delta = Delta()..insert('\n') {
-    _loadDocument(_delta);
-  }
-
-  Document.fromJson(List data) : _delta = _transform(Delta.fromJson(data)) {
-    _loadDocument(_delta);
-  }
-
-  Document.fromDelta(Delta delta) : _delta = delta {
-    _loadDocument(delta);
-  }
-
   Delta insert(int index, Object? data) {
     assert(index >= 0);
     assert(data is String || data is Embeddable);
@@ -56,14 +56,14 @@ class Document {
       return Delta();
     }
 
-    Delta delta = _rules.apply(RuleType.INSERT, this, index, data: data);
+    final delta = _rules.apply(RuleType.INSERT, this, index, data: data);
     compose(delta, ChangeSource.LOCAL);
     return delta;
   }
 
   Delta delete(int index, int len) {
     assert(index >= 0 && len > 0);
-    Delta delta = _rules.apply(RuleType.DELETE, this, index, len: len);
+    final delta = _rules.apply(RuleType.DELETE, this, index, len: len);
     if (delta.isNotEmpty) {
       compose(delta, ChangeSource.LOCAL);
     }
@@ -74,18 +74,18 @@ class Document {
     assert(index >= 0);
     assert(data is String || data is Embeddable);
 
-    bool dataIsNotEmpty = (data is String) ? data.isNotEmpty : true;
+    final dataIsNotEmpty = (data is String) ? data.isNotEmpty : true;
 
     assert(dataIsNotEmpty || len > 0);
 
-    Delta delta = Delta();
+    var delta = Delta();
 
     if (dataIsNotEmpty) {
       delta = insert(index + len, data);
     }
 
     if (len > 0) {
-      Delta deleteDelta = delete(index, len);
+      final deleteDelta = delete(index, len);
       delta = delta.compose(deleteDelta);
     }
 
@@ -95,9 +95,9 @@ class Document {
   Delta format(int index, int len, Attribute? attribute) {
     assert(index >= 0 && len >= 0 && attribute != null);
 
-    Delta delta = Delta();
+    var delta = Delta();
 
-    Delta formatDelta = _rules.apply(RuleType.FORMAT, this, index,
+    final formatDelta = _rules.apply(RuleType.FORMAT, this, index,
         len: len, attribute: attribute);
     if (formatDelta.isNotEmpty) {
       compose(formatDelta, ChangeSource.LOCAL);
@@ -108,16 +108,16 @@ class Document {
   }
 
   Style collectStyle(int index, int len) {
-    ChildQuery res = queryChild(index);
+    final res = queryChild(index);
     return (res.node as Line).collectStyle(res.offset, len);
   }
 
   ChildQuery queryChild(int offset) {
-    ChildQuery res = _root.queryChild(offset, true);
+    final res = _root.queryChild(offset, true);
     if (res.node is Line) {
       return res;
     }
-    Block block = res.node as Block;
+    final block = res.node as Block;
     return block.queryChild(res.offset, true);
   }
 
@@ -126,11 +126,11 @@ class Document {
     delta.trim();
     assert(delta.isNotEmpty);
 
-    int offset = 0;
+    var offset = 0;
     delta = _transform(delta);
-    Delta originalDelta = toDelta();
+    final originalDelta = toDelta();
-    for (Operation op in delta.toList()) {
+    for (final op in delta.toList()) {
-      Style? style =
+      final style =
           op.attributes != null ? Style.fromJson(op.attributes) : null;
 
       if (op.isInsert) {
@@ -172,10 +172,10 @@ class Document {
   bool get hasRedo => _history.hasRedo;
 
   static Delta _transform(Delta delta) {
-    Delta res = Delta();
+    final res = Delta();
-    List<Operation> ops = delta.toList();
+    final ops = delta.toList();
-    for (int i = 0; i < ops.length; i++) {
+    for (var i = 0; i < ops.length; i++) {
-      Operation op = ops[i];
+      final op = ops[i];
       res.push(op);
       _handleImageInsert(i, ops, op, res);
     }
@@ -184,14 +184,14 @@ class Document {
 
   static void _handleImageInsert(
       int i, List<Operation> ops, Operation op, Delta res) {
-    bool nextOpIsImage =
+    final nextOpIsImage =
         i + 1 < ops.length && ops[i + 1].isInsert && ops[i + 1].data is! String;
     if (nextOpIsImage && !(op.data as String).endsWith('\n')) {
       res.push(Operation.insert('\n'));
     }
     // Currently embed is equivalent to image and hence `is! String`
-    bool opInsertImage = op.isInsert && op.data is! String;
+    final opInsertImage = op.isInsert && op.data is! String;
-    bool nextOpIsLineBreak = i + 1 < ops.length &&
+    final nextOpIsLineBreak = i + 1 < ops.length &&
         ops[i + 1].isInsert &&
         ops[i + 1].data is String &&
         (ops[i + 1].data as String).startsWith('\n');
@@ -221,7 +221,7 @@ class Document {
 
   void _loadDocument(Delta doc) {
     assert((doc.last.data as String).endsWith('\n'));
-    int offset = 0;
+    var offset = 0;
     for (final op in doc.toList()) {
       if (!op.isInsert) {
         throw ArgumentError.value(doc,
@@ -247,12 +247,12 @@ class Document {
       return false;
     }
 
-    final Node node = root.children.first;
+    final node = root.children.first;
     if (!node.isLast) {
       return false;
     }
 
-    Delta delta = node.toDelta();
+    final delta = node.toDelta();
     return delta.length == 1 &&
         delta.first.data == '\n' &&
         delta.first.key == 'insert';

lib/models/documents/history.dart

@@ -1,9 +1,17 @@
-import 'package:flutter_quill/models/quill_delta.dart';
 import 'package:tuple/tuple.dart';
 
+import '../quill_delta.dart';
 import 'document.dart';
 
 class History {
+  History({
+    this.ignoreChange = false,
+    this.interval = 400,
+    this.maxStack = 100,
+    this.userOnly = false,
+    this.lastRecorded = 0,
+  });
+
   final HistoryStack stack = HistoryStack.empty();
 
   bool get hasUndo => stack.undo.isNotEmpty;
@@ -24,13 +32,6 @@ class History {
   ///record delay
   final int interval;
 
-  History(
-      {this.ignoreChange = false,
-      this.interval = 400,
-      this.maxStack = 100,
-      this.userOnly = false,
-      this.lastRecorded = 0});
-
   void handleDocChange(Tuple3<Delta, Delta, ChangeSource> change) {
     if (ignoreChange) return;
     if (!userOnly || change.item3 == ChangeSource.LOCAL) {
@@ -47,7 +48,7 @@ class History {
   void record(Delta change, Delta before) {
     if (change.isEmpty) return;
     stack.redo.clear();
-    Delta undoDelta = change.invert(before);
+    var undoDelta = change.invert(before);
     final timeStamp = DateTime.now().millisecondsSinceEpoch;
 
     if (lastRecorded + interval > timeStamp && stack.undo.isNotEmpty) {
@@ -74,7 +75,7 @@ class History {
   }
 
   void transformStack(List<Delta> stack, Delta delta) {
-    for (int i = stack.length - 1; i >= 0; i -= 1) {
+    for (var i = stack.length - 1; i >= 0; i -= 1) {
       final oldDelta = stack[i];
       stack[i] = delta.transform(oldDelta, true);
       delta = oldDelta.transform(delta, false);
@@ -88,10 +89,10 @@ class History {
     if (source.isEmpty) {
       return const Tuple2(false, 0);
     }
-    Delta delta = source.removeLast();
+    final delta = source.removeLast();
     // look for insert or delete
     int? len = 0;
-    List<Operation> ops = delta.toList();
+    final ops = delta.toList();
     for (var i = 0; i < ops.length; i++) {
       if (ops[i].key == Operation.insertKey) {
         len = ops[i].length;
@@ -99,8 +100,8 @@ class History {
         len = ops[i].length! * -1;
       }
     }
-    Delta base = Delta.from(doc.toDelta());
+    final base = Delta.from(doc.toDelta());
-    Delta inverseDelta = delta.invert(base);
+    final inverseDelta = delta.invert(base);
     dest.add(inverseDelta);
     lastRecorded = 0;
     ignoreChange = true;
@@ -119,13 +120,13 @@ class History {
 }
 
 class HistoryStack {
-  final List<Delta> undo;
-  final List<Delta> redo;
-
   HistoryStack.empty()
       : undo = [],
         redo = [];
 
+  final List<Delta> undo;
+  final List<Delta> redo;
+
   void clear() {
     undo.clear();
     redo.clear();

lib/models/documents/nodes/block.dart

@@ -1,10 +1,23 @@
-import 'package:flutter_quill/models/quill_delta.dart';
+import '../../quill_delta.dart';
-
 import 'container.dart';
 import 'line.dart';
 import 'node.dart';
 
+/// Represents a group of adjacent [Line]s with the same block style.
+///
+/// Block elements are:
+/// - Blockquote
+/// - Header
+/// - Indent
+/// - List
+/// - Text Alignment
+/// - Text Direction
+/// - Code Block
 class Block extends Container<Line?> {
+  /// Creates new unmounted [Block].
+  @override
+  Node newInstance() => Block();
+
   @override
   Line get defaultChild => Line();
 
@@ -18,7 +31,7 @@ class Block extends Container<Line?> {
   @override
   void adjust() {
     if (isEmpty) {
-      Node? sibling = previous;
+      final sibling = previous;
       unlink();
       if (sibling != null) {
         sibling.adjust();
@@ -26,17 +39,18 @@ class Block extends Container<Line?> {
       return;
     }
 
-    Block block = this;
+    var block = this;
-    Node? prev = block.previous;
+    final prev = block.previous;
     // merging it with previous block if style is the same
     if (!block.isFirst &&
         block.previous is Block &&
         prev!.style == block.style) {
-      block.moveChildToNewParent(prev as Container<Node?>?);
+      block
-      block.unlink();
+        ..moveChildToNewParent(prev as Container<Node?>?)
+        ..unlink();
       block = prev as Block;
     }
-    Node? next = block.next;
+    final next = block.next;
     // merging it with next block if style is the same
     if (!block.isLast && block.next is Block && next!.style == block.style) {
       (next as Block).moveChildToNewParent(block);
@@ -48,16 +62,11 @@ class Block extends Container<Line?> {
   String toString() {
     final block = style.attributes.toString();
     final buffer = StringBuffer('§ {$block}\n');
-    for (var child in children) {
+    for (final child in children) {
       final tree = child.isLast ? '└' : '├';
       buffer.write('  $tree $child');
       if (!child.isLast) buffer.writeln();
     }
     return buffer.toString();
   }
-
-  @override
-  Node newInstance() {
-    return Block();
-  }
 }

lib/models/documents/nodes/container.dart

@@ -1,70 +1,99 @@
 import 'dart:collection';
 
 import '../style.dart';
+import 'leaf.dart';
+import 'line.dart';
 import 'node.dart';
 
-/* Container of multiple nodes */
+/// Container can accommodate other nodes.
+///
+/// Delegates insert, retain and delete operations to children nodes. For each
+/// operation container looks for a child at specified index position and
+/// forwards operation to that child.
+///
+/// Most of the operation handling logic is implemented by [Line] and [Text].
 abstract class Container<T extends Node?> extends Node {
   final LinkedList<Node> _children = LinkedList<Node>();
 
+  /// List of children.
   LinkedList<Node> get children => _children;
 
+  /// Returns total number of child nodes in this container.
+  ///
+  /// To get text length of this container see [length].
   int get childCount => _children.length;
 
+  /// Returns the first child [Node].
   Node get first => _children.first;
 
+  /// Returns the last child [Node].
   Node get last => _children.last;
 
+  /// Returns `true` if this container has no child nodes.
   bool get isEmpty => _children.isEmpty;
 
+  /// Returns `true` if this container has at least 1 child.
   bool get isNotEmpty => _children.isNotEmpty;
 
-  /// abstract methods begin
+  /// Returns an instance of default child for this container node.
-
+  ///
+  /// Always returns fresh instance.
   T get defaultChild;
 
-  /// abstract methods end
+  /// Adds [node] to the end of this container children list.
-
   void add(T node) {
     assert(node?.parent == null);
     node?.parent = this;
     _children.add(node as Node);
   }
 
+  /// Adds [node] to the beginning of this container children list.
   void addFirst(T node) {
     assert(node?.parent == null);
     node?.parent = this;
     _children.addFirst(node as Node);
   }
 
+  /// Removes [node] from this container.
   void remove(T node) {
     assert(node?.parent == this);
     node?.parent = null;
     _children.remove(node as Node);
   }
 
+  /// Moves children of this node to [newParent].
   void moveChildToNewParent(Container? newParent) {
     if (isEmpty) {
       return;
     }
 
-    T? last = newParent!.isEmpty ? null : newParent.last as T?;
+    final last = newParent!.isEmpty ? null : newParent.last as T?;
     while (isNotEmpty) {
-      T child = first as T;
+      final child = first as T;
       child?.unlink();
       newParent.add(child);
     }
 
+    /// In case [newParent] already had children we need to make sure
+    /// combined list is optimized.
     if (last != null) last.adjust();
   }
 
+  /// Queries the child [Node] at specified character [offset] in this container.
+  ///
+  /// The result may contain the found node or `null` if no node is found
+  /// at specified offset.
+  ///
+  /// [ChildQuery.offset] is set to relative offset within returned child node
+  /// which points at the same character position in the document as the
+  /// original [offset].
   ChildQuery queryChild(int offset, bool inclusive) {
     if (offset < 0 || offset > length) {
       return ChildQuery(null, 0);
     }
 
-    for (Node node in children) {
+    for (final node in children) {
-      int len = node.length;
+      final len = node.length;
       if (offset < len || (inclusive && offset == len && (node.isLast))) {
         return ChildQuery(node, offset);
       }
@@ -76,6 +105,9 @@ abstract class Container<T extends Node?> extends Node {
   @override
   String toPlainText() => children.map((child) => child.toPlainText()).join();
 
+  /// Content length of this node's children.
+  ///
+  /// To get number of children in this node use [childCount].
   @override
   int get length => _children.fold(0, (cur, node) => cur + node.length);
 
@@ -84,14 +116,14 @@ abstract class Container<T extends Node?> extends Node {
     assert(index == 0 || (index > 0 && index < length));
 
     if (isNotEmpty) {
-      ChildQuery child = queryChild(index, false);
+      final child = queryChild(index, false);
       child.node!.insert(child.offset, data, style);
       return;
     }
 
     // empty
     assert(index == 0);
-    T node = defaultChild;
+    final node = defaultChild;
     add(node);
     node?.insert(index, data, style);
   }
@@ -99,14 +131,14 @@ abstract class Container<T extends Node?> extends Node {
   @override
   void retain(int index, int? length, Style? attributes) {
     assert(isNotEmpty);
-    ChildQuery child = queryChild(index, false);
+    final child = queryChild(index, false);
     child.node!.retain(child.offset, length, attributes);
   }
 
   @override
   void delete(int index, int? length) {
     assert(isNotEmpty);
-    ChildQuery child = queryChild(index, false);
+    final child = queryChild(index, false);
     child.node!.delete(child.offset, length);
   }
 
@@ -114,11 +146,15 @@ abstract class Container<T extends Node?> extends Node {
   String toString() => _children.join('\n');
 }
 
-/// Query of a child in a Container
+/// Result of a child query in a [Container].
 class ChildQuery {
-  final Node? node; // null if not found
+  ChildQuery(this.node, this.offset);
 
-  final int offset;
+  /// The child node if found, otherwise `null`.
+  final Node? node;
 
-  ChildQuery(this.node, this.offset);
+  /// Starting offset within the child [node] which points at the same
+  /// character in the document as the original offset passed to
+  /// [Container.queryChild] method.
+  final int offset;
 }

lib/models/documents/nodes/embed.dart

@@ -1,26 +1,40 @@
+/// An object which can be embedded into a Quill document.
+///
+/// See also:
+///
+/// * [BlockEmbed] which represents a block embed.
 class Embeddable {
+  Embeddable(this.type, this.data);
+
+  /// The type of this object.
   final String type;
-  final dynamic data;
 
-  Embeddable(this.type, this.data);
+  /// The data payload of this object.
+  final dynamic data;
 
   Map<String, dynamic> toJson() {
-    Map<String, String> m = {type: data};
+    final m = <String, String>{type: data};
     return m;
   }
 
   static Embeddable fromJson(Map<String, dynamic> json) {
-    Map<String, dynamic> m = Map<String, dynamic>.from(json);
+    final m = Map<String, dynamic>.from(json);
     assert(m.length == 1, 'Embeddable map has one key');
 
     return BlockEmbed(m.keys.first, m.values.first);
   }
 }
 
+/// An object which occupies an entire line in a document and cannot co-exist
+/// inline with regular text.
+///
+/// There are two built-in embed types supported by Quill documents, however
+/// the document model itself does not make any assumptions about the types
+/// of embedded objects and allows users to define their own types.
 class BlockEmbed extends Embeddable {
   BlockEmbed(String type, String data) : super(type, data);
 
-  static final BlockEmbed horizontalRule = BlockEmbed('divider', 'hr');
+  static BlockEmbed horizontalRule = BlockEmbed('divider', 'hr');
 
   static BlockEmbed image(String imageUrl) => BlockEmbed('image', imageUrl);
 }

lib/models/documents/nodes/leaf.dart

@@ -1,29 +1,30 @@
 import 'dart:math' as math;
 
-import 'package:flutter_quill/models/quill_delta.dart';
+import '../../quill_delta.dart';
-
 import '../style.dart';
 import 'embed.dart';
 import 'line.dart';
 import 'node.dart';
 
-/* A leaf node in document tree */
+/// A leaf in Quill document tree.
 abstract class Leaf extends Node {
-  Object _value;
+  /// Creates a new [Leaf] with specified [data].
-
-  Object get value => _value;
-
-  Leaf.val(Object val) : _value = val;
-
   factory Leaf(Object data) {
     if (data is Embeddable) {
       return Embed(data);
     }
-    String text = data as String;
+    final text = data as String;
     assert(text.isNotEmpty);
     return Text(text);
   }
 
+  Leaf.val(Object val) : _value = val;
+
+  /// Contents of this node, either a String if this is a [Text] or an
+  /// [Embed] if this is an [BlockEmbed].
+  Object get value => _value;
+  Object _value;
+
   @override
   void applyStyle(Style value) {
     assert(value.isInline || value.isIgnored || value.isEmpty,
@@ -45,14 +46,15 @@ abstract class Leaf extends Node {
 
   @override
   Delta toDelta() {
-    var data = _value is Embeddable ? (_value as Embeddable).toJson() : _value;
+    final data =
+        _value is Embeddable ? (_value as Embeddable).toJson() : _value;
     return Delta()..insert(data, style.toJson());
   }
 
   @override
   void insert(int index, Object data, Style? style) {
     assert(index >= 0 && index <= length);
-    Leaf node = Leaf(data);
+    final node = Leaf(data);
     if (index < length) {
       splitAt(index)!.insertBefore(node);
     } else {
@@ -67,9 +69,9 @@ abstract class Leaf extends Node {
       return;
     }
 
-    int local = math.min(length - index, len!);
+    final local = math.min(length - index, len!);
-    int remain = len - local;
+    final remain = len - local;
-    Leaf node = _isolate(index, local);
+    final node = _isolate(index, local);
 
     if (remain > 0) {
       assert(node.next != null);
@@ -82,13 +84,13 @@ abstract class Leaf extends Node {
   void delete(int index, int? len) {
     assert(index < length);
 
-    int local = math.min(length - index, len!);
+    final local = math.min(length - index, len!);
-    Leaf target = _isolate(index, local);
+    final target = _isolate(index, local);
-    Leaf? prev = target.previous as Leaf?;
+    final prev = target.previous as Leaf?;
-    Leaf? next = target.next as Leaf?;
+    final next = target.next as Leaf?;
     target.unlink();
 
-    int remain = len - local;
+    final remain = len - local;
     if (remain > 0) {
       assert(next != null);
       next!.delete(0, remain);
@@ -99,36 +101,47 @@ abstract class Leaf extends Node {
     }
   }
 
+  /// Adjust this text node by merging it with adjacent nodes if they share
+  /// the same style.
   @override
   void adjust() {
     if (this is Embed) {
+      // Embed nodes cannot be merged with text nor other embeds (in fact,
+      // there could be no two adjacent embeds on the same line since an
+      // embed occupies an entire line).
       return;
     }
 
-    Text node = this as Text;
+    // This is a text node and it can only be merged with other text nodes.
-    // merging it with previous node if style is the same
+    var node = this as Text;
-    Node? prev = node.previous;
+
+    // Merging it with previous node if style is the same.
+    final prev = node.previous;
     if (!node.isFirst && prev is Text && prev.style == node.style) {
       prev._value = prev.value + node.value;
       node.unlink();
       node = prev;
     }
 
-    // merging it with next node if style is the same
+    // Merging it with next node if style is the same.
-    Node? next = node.next;
+    final next = node.next;
     if (!node.isLast && next is Text && next.style == node.style) {
       node._value = node.value + next.value;
       next.unlink();
     }
   }
 
-  Leaf? cutAt(int index) {
+  /// Splits this leaf node at [index] and returns new node.
-    assert(index >= 0 && index <= length);
+  ///
-    Leaf? cut = splitAt(index);
+  /// If this is the last node in its list and [index] equals this node's
-    cut?.unlink();
+  /// length then this method returns `null` as there is nothing left to split.
-    return cut;
+  /// If there is another leaf node after this one and [index] equals this
-  }
+  /// node's length then the next leaf node is returned.
-
+  ///
+  /// If [index] equals to `0` then this node itself is returned unchanged.
+  ///
+  /// In case a new node is actually split from this one, it inherits this
+  /// node's style.
   Leaf? splitAt(int index) {
     assert(index >= 0 && index <= length);
     if (index == 0) {
@@ -139,64 +152,101 @@ abstract class Leaf extends Node {
     }
 
     assert(this is Text);
-    String text = _value as String;
+    final text = _value as String;
     _value = text.substring(0, index);
-    Leaf split = Leaf(text.substring(index));
+    final split = Leaf(text.substring(index))..applyStyle(style);
-    split.applyStyle(style);
     insertAfter(split);
     return split;
   }
 
+  /// Cuts a leaf from [index] to the end of this node and returns new node
+  /// in detached state (e.g. [mounted] returns `false`).
+  ///
+  /// Splitting logic is identical to one described in [splitAt], meaning this
+  /// method may return `null`.
+  Leaf? cutAt(int index) {
+    assert(index >= 0 && index <= length);
+    final cut = splitAt(index);
+    cut?.unlink();
+    return cut;
+  }
+
+  /// Formats this node and optimizes it with adjacent leaf nodes if needed.
   void format(Style? style) {
     if (style != null && style.isNotEmpty) {
       applyStyle(style);
     }
-
     adjust();
   }
 
+  /// Isolates a new leaf starting at [index] with specified [length].
+  ///
+  /// Splitting logic is identical to one described in [splitAt], with one
+  /// exception that it is required for [index] to always be less than this
+  /// node's length. As a result this method always returns a [LeafNode]
+  /// instance. Returned node may still be the same as this node
+  /// if provided [index] is `0`.
   Leaf _isolate(int index, int length) {
     assert(
         index >= 0 && index < this.length && (index + length <= this.length));
-    Leaf target = splitAt(index)!;
+    final target = splitAt(index)!..splitAt(length);
-    target.splitAt(length);
     return target;
   }
 }
 
+/// A span of formatted text within a line in a Quill document.
+///
+/// Text is a leaf node of a document tree.
+///
+/// Parent of a text node is always a [Line], and as a consequence text
+/// node's [value] cannot contain any line-break characters.
+///
+/// See also:
+///
+///   * [Embed], a leaf node representing an embeddable object.
+///   * [Line], a node representing a line of text.
 class Text extends Leaf {
   Text([String text = ''])
       : assert(!text.contains('\n')),
         super.val(text);
 
   @override
-  String get value => _value as String;
+  Node newInstance() => Text();
 
   @override
-  String toPlainText() {
+  String get value => _value as String;
-    return value;
-  }
 
   @override
-  Node newInstance() {
+  String toPlainText() => value;
-    return Text();
-  }
 }
 
-/// An embedded node such as image or video
+/// An embed node inside of a line in a Quill document.
+///
+/// Embed node is a leaf node similar to [Text]. It represents an arbitrary
+/// piece of non-textual content embedded into a document, such as, image,
+/// horizontal rule, video, or any other object with defined structure,
+/// like a tweet, for instance.
+///
+/// Embed node's length is always `1` character and it is represented with
+/// unicode object replacement character in the document text.
+///
+/// Any inline style can be applied to an embed, however this does not
+/// necessarily mean the embed will look according to that style. For instance,
+/// applying "bold" style to an image gives no effect, while adding a "link" to
+/// an image actually makes the image react to user's action.
 class Embed extends Leaf {
   Embed(Embeddable data) : super.val(data);
 
+  static const kObjectReplacementCharacter = '\uFFFC';
+
   @override
-  Embeddable get value => super.value as Embeddable;
+  Node newInstance() => throw UnimplementedError();
 
   @override
-  String toPlainText() {
+  Embeddable get value => super.value as Embeddable;
-    return '\uFFFC';
-  }
 
+  /// // Embed nodes are represented as unicode object replacement character in
+  // plain text.
   @override
-  Node newInstance() {
+  String toPlainText() => kObjectReplacementCharacter;
-    throw UnimplementedError();
-  }
 }

lib/models/documents/nodes/line.dart

@@ -1,15 +1,20 @@
 import 'dart:math' as math;
 
-import 'package:flutter_quill/models/documents/attribute.dart';
+import '../../quill_delta.dart';
-import 'package:flutter_quill/models/documents/nodes/node.dart';
+import '../attribute.dart';
-import 'package:flutter_quill/models/quill_delta.dart';
-
 import '../style.dart';
 import 'block.dart';
 import 'container.dart';
 import 'embed.dart';
 import 'leaf.dart';
-
+import 'node.dart';
+
+/// A line of rich text in a Quill document.
+///
+/// Line serves as a container for [Leaf]s, like [Text] and [Embed].
+///
+/// When a line contains an embed, it fully occupies the line, no other embeds
+/// or text nodes are allowed.
 class Line extends Container<Leaf?> {
   @override
   Leaf get defaultChild => Text();
@@ -17,6 +22,7 @@ class Line extends Container<Leaf?> {
   @override
   int get length => super.length + 1;
 
+  /// Returns `true` if this line contains an embedded object.
   bool get hasEmbed {
     if (childCount != 1) {
       return false;
@@ -25,6 +31,7 @@ class Line extends Container<Leaf?> {
     return children.single is Embed;
   }
 
+  /// Returns next [Line] or `null` if this is the last line in the document.
   Line? get nextLine {
     if (!isLast) {
       return next is Block ? (next as Block).first as Line? : next as Line?;
@@ -41,6 +48,9 @@ class Line extends Container<Leaf?> {
         : parent!.next as Line?;
   }
 
+  @override
+  Node newInstance() => Line();
+
   @override
   Delta toDelta() {
     final delta = children
@@ -48,7 +58,7 @@ class Line extends Container<Leaf?> {
         .fold(Delta(), (dynamic a, b) => a.concat(b));
     var attributes = style;
     if (parent is Block) {
-      Block block = parent as Block;
+      final block = parent as Block;
       attributes = attributes.mergeAll(block.style);
     }
     delta.insert('\n', attributes.toJson());
@@ -56,7 +66,7 @@ class Line extends Container<Leaf?> {
   }
 
   @override
-  String toPlainText() => super.toPlainText() + '\n';
+  String toPlainText() => '${super.toPlainText()}\n';
 
   @override
   String toString() {
@@ -68,35 +78,43 @@ class Line extends Container<Leaf?> {
   @override
   void insert(int index, Object data, Style? style) {
     if (data is Embeddable) {
-      _insert(index, data, style);
+      // We do not check whether this line already has any children here as
+      // inserting an embed into a line with other text is acceptable from the
+      // Delta format perspective.
+      // We rely on heuristic rules to ensure that embeds occupy an entire line.
+      _insertSafe(index, data, style);
       return;
     }
 
-    String text = data as String;
+    final text = data as String;
-    int lineBreak = text.indexOf('\n');
+    final lineBreak = text.indexOf('\n');
     if (lineBreak < 0) {
-      _insert(index, text, style);
+      _insertSafe(index, text, style);
+      // No need to update line or block format since those attributes can only
+      // be attached to `\n` character and we already know it's not present.
       return;
     }
 
-    String prefix = text.substring(0, lineBreak);
+    final prefix = text.substring(0, lineBreak);
-    _insert(index, prefix, style);
+    _insertSafe(index, prefix, style);
     if (prefix.isNotEmpty) {
       index += prefix.length;
     }
 
-    Line nextLine = _getNextLine(index);
+    // Next line inherits our format.
+    final nextLine = _getNextLine(index);
 
+    // Reset our format and unwrap from a block if needed.
     clearStyle();
-
     if (parent is Block) {
       _unwrap();
     }
 
+    // Now we can apply new format and re-layout.
     _format(style);
 
-    // Continue with the remaining
+    // Continue with remaining part.
-    String remain = text.substring(lineBreak + 1);
+    final remain = text.substring(lineBreak + 1);
     nextLine.insert(0, remain, style);
   }
 
@@ -105,20 +123,24 @@ class Line extends Container<Leaf?> {
     if (style == null) {
       return;
     }
-    int thisLen = length;
+    final thisLength = length;
 
-    int local = math.min(thisLen - index, len!);
+    final local = math.min(thisLength - index, len!);
+    // If index is at newline character then this is a line/block style update.
+    final isLineFormat = (index + local == thisLength) && local == 1;
 
-    if (index + local == thisLen && local == 1) {
+    if (isLineFormat) {
-      assert(style.values.every((attr) => attr.scope == AttributeScope.BLOCK));
+      assert(style.values.every((attr) => attr.scope == AttributeScope.BLOCK),
+          'It is not allowed to apply inline attributes to line itself.');
       _format(style);
     } else {
+      // Otherwise forward to children as it's an inline format update.
       assert(style.values.every((attr) => attr.scope == AttributeScope.INLINE));
-      assert(index + local != thisLen);
+      assert(index + local != thisLength);
       super.retain(index, local, style);
     }
 
-    int remain = len - local;
+    final remain = len - local;
     if (remain > 0) {
       assert(nextLine != null);
       nextLine!.retain(0, remain, style);
@@ -127,66 +149,80 @@ class Line extends Container<Leaf?> {
 
   @override
   void delete(int index, int? len) {
-    int local = math.min(length - index, len!);
+    final local = math.min(length - index, len!);
-    bool deleted = index + local == length;
+    final isLFDeleted = index + local == length; // Line feed
-    if (deleted) {
+    if (isLFDeleted) {
+      // Our newline character deleted with all style information.
       clearStyle();
       if (local > 1) {
+        // Exclude newline character from delete range for children.
         super.delete(index, local - 1);
       }
     } else {
       super.delete(index, local);
     }
 
-    int remain = len - local;
+    final remaining = len - local;
-    if (remain > 0) {
+    if (remaining > 0) {
       assert(nextLine != null);
-      nextLine!.delete(0, remain);
+      nextLine!.delete(0, remaining);
     }
 
-    if (deleted && isNotEmpty) {
+    if (isLFDeleted && isNotEmpty) {
+      // Since we lost our line-break and still have child text nodes those must
+      // migrate to the next line.
+
+      // nextLine might have been unmounted since last assert so we need to
+      // check again we still have a line after us.
       assert(nextLine != null);
+
+      // Move remaining children in this line to the next line so that all
+      // attributes of nextLine are preserved.
       nextLine!.moveChildToNewParent(this);
       moveChildToNewParent(nextLine);
     }
 
-    if (deleted) {
+    if (isLFDeleted) {
-      Node p = parent!;
+      // Now we can remove this line.
+      final block = parent!; // remember reference before un-linking.
       unlink();
-      p.adjust();
+      block.adjust();
     }
   }
 
+  /// Formats this line.
   void _format(Style? newStyle) {
     if (newStyle == null || newStyle.isEmpty) {
       return;
     }
 
     applyStyle(newStyle);
-    Attribute? blockStyle = newStyle.getBlockExceptHeader();
+    final blockStyle = newStyle.getBlockExceptHeader();
     if (blockStyle == null) {
       return;
-    }
+    } // No block-level changes
 
     if (parent is Block) {
-      Attribute? parentStyle = (parent as Block).style.getBlockExceptHeader();
+      final parentStyle = (parent as Block).style.getBlockExceptHeader();
       if (blockStyle.value == null) {
         _unwrap();
       } else if (blockStyle != parentStyle) {
         _unwrap();
-        Block block = Block();
+        final block = Block()..applyAttribute(blockStyle);
-        block.applyAttribute(blockStyle);
         _wrap(block);
         block.adjust();
-      }
+      } // else the same style, no-op.
     } else if (blockStyle.value != null) {
-      Block block = Block();
+      // Only wrap with a new block if this is not an unset
-      block.applyAttribute(blockStyle);
+      final block = Block()..applyAttribute(blockStyle);
       _wrap(block);
       block.adjust();
     }
   }
 
+  /// Wraps this line with new parent [block].
+  ///
+  /// This line can not be in a [Block] when this method is called.
   void _wrap(Block block) {
     assert(parent != null && parent is! Block);
     insertAfter(block);
@@ -194,11 +230,14 @@ class Line extends Container<Leaf?> {
     block.add(this);
   }
 
+  /// Unwraps this line from it's parent [Block].
+  ///
+  /// This method asserts if current [parent] of this line is not a [Block].
   void _unwrap() {
     if (parent is! Block) {
       throw ArgumentError('Invalid parent');
     }
-    Block block = parent as Block;
+    final block = parent as Block;
 
     assert(block.children.contains(this));
 
@@ -209,10 +248,10 @@ class Line extends Container<Leaf?> {
       unlink();
       block.insertAfter(this);
     } else {
-      Block before = block.clone() as Block;
+      final before = block.clone() as Block;
       block.insertBefore(before);
 
-      Line child = block.first as Line;
+      var child = block.first as Line;
       while (child != this) {
         child.unlink();
         before.add(child);
@@ -227,26 +266,25 @@ class Line extends Container<Leaf?> {
   Line _getNextLine(int index) {
     assert(index == 0 || (index > 0 && index < length));
 
-    Line line = clone() as Line;
+    final line = clone() as Line;
     insertAfter(line);
     if (index == length - 1) {
       return line;
     }
 
-    ChildQuery query = queryChild(index, false);
+    final query = queryChild(index, false);
     while (!query.node!.isLast) {
-      Leaf next = last as Leaf;
+      final next = (last as Leaf)..unlink();
-      next.unlink();
       line.addFirst(next);
     }
-    Leaf child = query.node as Leaf;
+    final child = query.node as Leaf;
-    Leaf? cut = child.splitAt(query.offset);
+    final cut = child.splitAt(query.offset);
     cut?.unlink();
     line.addFirst(cut);
     return line;
   }
 
-  void _insert(int index, Object data, Style? style) {
+  void _insertSafe(int index, Object data, Style? style) {
     assert(index == 0 || (index > 0 && index < length));
 
     if (data is String) {
@@ -256,47 +294,51 @@ class Line extends Container<Leaf?> {
       }
     }
 
-    if (isNotEmpty) {
+    if (isEmpty) {
-      ChildQuery result = queryChild(index, true);
+      final child = Leaf(data);
+      add(child);
+      child.format(style);
+    } else {
+      final result = queryChild(index, true);
       result.node!.insert(result.offset, data, style);
-      return;
     }
-
-    Leaf child = Leaf(data);
-    add(child);
-    child.format(style);
-  }
-
-  @override
-  Node newInstance() {
-    return Line();
   }
 
+  /// Returns style for specified text range.
+  ///
+  /// Only attributes applied to all characters within this range are
+  /// included in the result. Inline and line level attributes are
+  /// handled separately, e.g.:
+  ///
+  /// - line attribute X is included in the result only if it exists for
+  ///   every line within this range (partially included lines are counted).
+  /// - inline attribute X is included in the result only if it exists
+  ///   for every character within this range (line-break characters excluded).
   Style collectStyle(int offset, int len) {
-    int local = math.min(length - offset, len);
+    final local = math.min(length - offset, len);
-    Style res = Style();
+    var result = Style();
-    var excluded = <Attribute>{};
+    final excluded = <Attribute>{};
 
     void _handle(Style style) {
-      if (res.isEmpty) {
+      if (result.isEmpty) {
         excluded.addAll(style.values);
       } else {
-        for (Attribute attr in res.values) {
+        for (final attr in result.values) {
           if (!style.containsKey(attr.key)) {
             excluded.add(attr);
           }
         }
       }
-      Style remain = style.removeAll(excluded);
+      final remaining = style.removeAll(excluded);
-      res = res.removeAll(excluded);
+      result = result.removeAll(excluded);
-      res = res.mergeAll(remain);
+      result = result.mergeAll(remaining);
     }
 
-    ChildQuery data = queryChild(offset, true);
+    final data = queryChild(offset, true);
-    Leaf? node = data.node as Leaf?;
+    var node = data.node as Leaf?;
     if (node != null) {
-      res = res.mergeAll(node.style);
+      result = result.mergeAll(node.style);
-      int pos = node.length - data.offset;
+      var pos = node.length - data.offset;
       while (!node!.isLast && pos < local) {
         node = node.next as Leaf?;
         _handle(node!.style);
@@ -304,17 +346,18 @@ class Line extends Container<Leaf?> {
       }
     }
 
-    res = res.mergeAll(style);
+    result = result.mergeAll(style);
     if (parent is Block) {
-      Block block = parent as Block;
+      final block = parent as Block;
-      res = res.mergeAll(block.style);
+      result = result.mergeAll(block.style);
     }
 
-    int remain = len - local;
+    final remaining = len - local;
-    if (remain > 0) {
+    if (remaining > 0) {
-      _handle(nextLine!.collectStyle(0, remain));
+      final rest = nextLine!.collectStyle(0, remaining);
+      _handle(rest);
     }
 
-    return res;
+    return result;
   }
 }

lib/models/documents/nodes/node.dart

@@ -1,51 +1,49 @@
 import 'dart:collection';
 
-import 'package:flutter_quill/models/documents/style.dart';
+import '../../quill_delta.dart';
-import 'package:flutter_quill/models/quill_delta.dart';
-
 import '../attribute.dart';
+import '../style.dart';
 import 'container.dart';
 import 'line.dart';
 
-/* node in a document tree */
+/// An abstract node in a document tree.
+///
+/// Represents a segment of a Quill document with specified [offset]
+/// and [length].
+///
+/// The [offset] property is relative to [parent]. See also [documentOffset]
+/// which provides absolute offset of this node within the document.
+///
+/// The current parent node is exposed by the [parent] property.
 abstract class Node extends LinkedListEntry<Node> {
+  /// Current parent of this node. May be null if this node is not mounted.
   Container? parent;
-  Style _style = Style();
 
   Style get style => _style;
+  Style _style = Style();
 
-  void applyAttribute(Attribute attribute) {
+  /// Returns `true` if this node is the first node in the [parent] list.
-    _style = _style.merge(attribute);
-  }
-
-  void applyStyle(Style value) {
-    _style = _style.mergeAll(value);
-  }
-
-  void clearStyle() {
-    _style = Style();
-  }
-
   bool get isFirst => list!.first == this;
 
+  /// Returns `true` if this node is the last node in the [parent] list.
   bool get isLast => list!.last == this;
 
+  /// Length of this node in characters.
   int get length;
 
-  Node clone() {
+  Node clone() => newInstance()..applyStyle(style);
-    Node node = newInstance();
-    node.applyStyle(style);
-    return node;
-  }
 
-  int getOffset() {
+  /// Offset in characters of this node relative to [parent] node.
-    int offset = 0;
+  ///
+  /// To get offset of this node in the document see [documentOffset].
+  int get offset {
+    var offset = 0;
 
     if (list == null || isFirst) {
       return offset;
     }
 
-    Node cur = this;
+    var cur = this;
     do {
       cur = cur.previous!;
       offset += cur.length;
@@ -53,16 +51,31 @@ abstract class Node extends LinkedListEntry<Node> {
     return offset;
   }
 
-  int getDocumentOffset() {
+  /// Offset in characters of this node in the document.
-    final parentOffset = (parent is! Root) ? parent!.getDocumentOffset() : 0;
+  int get documentOffset {
-    return parentOffset + getOffset();
+    final parentOffset = (parent is! Root) ? parent!.documentOffset : 0;
+    return parentOffset + offset;
   }
 
+  /// Returns `true` if this node contains character at specified [offset] in
+  /// the document.
   bool containsOffset(int offset) {
-    final o = getDocumentOffset();
+    final o = documentOffset;
     return o <= offset && offset < o + length;
   }
 
+  void applyAttribute(Attribute attribute) {
+    _style = _style.merge(attribute);
+  }
+
+  void applyStyle(Style value) {
+    _style = _style.mergeAll(value);
+  }
+
+  void clearStyle() {
+    _style = Style();
+  }
+
   @override
   void insertBefore(Node entry) {
     assert(entry.parent == null && parent != null);
@@ -84,9 +97,7 @@ abstract class Node extends LinkedListEntry<Node> {
     super.unlink();
   }
 
-  void adjust() {
+  void adjust() {/* no-op */}
-    // do nothing
-  }
 
   /// abstract methods begin
 
@@ -103,11 +114,13 @@ abstract class Node extends LinkedListEntry<Node> {
   void delete(int index, int? len);
 
   /// abstract methods end
-
 }
 
-/* Root node of document tree */
+/// Root node of document tree.
 class Root extends Container<Container<Node?>> {
+  @override
+  Node newInstance() => Root();
+
   @override
   Container<Node?> get defaultChild => Line();
 
@@ -115,9 +128,4 @@ class Root extends Container<Container<Node?>> {
   Delta toDelta() => children
       .map((child) => child.toDelta())
       .fold(Delta(), (a, b) => a.concat(b));
-
-  @override
-  Node newInstance() {
-    return Root();
-  }
 }

lib/models/documents/style.dart

@@ -1,22 +1,23 @@
 import 'package:collection/collection.dart';
-import 'package:flutter_quill/models/documents/attribute.dart';
 import 'package:quiver/core.dart';
 
+import 'attribute.dart';
+
 /* Collection of style attributes */
 class Style {
-  final Map<String, Attribute> _attributes;
+  Style() : _attributes = <String, Attribute>{};
 
   Style.attr(this._attributes);
 
-  Style() : _attributes = <String, Attribute>{};
+  final Map<String, Attribute> _attributes;
 
   static Style fromJson(Map<String, dynamic>? attributes) {
     if (attributes == null) {
       return Style();
     }
 
-    Map<String, Attribute> result = attributes.map((String key, dynamic value) {
+    final result = attributes.map((key, dynamic value) {
-      Attribute attr = Attribute.fromKeyValue(key, value);
+      final attr = Attribute.fromKeyValue(key, value);
       return MapEntry<String, Attribute>(key, attr);
     });
     return Style.attr(result);
@@ -24,7 +25,7 @@ class Style {
 
   Map<String, dynamic>? toJson() => _attributes.isEmpty
       ? null
-      : _attributes.map<String, dynamic>((String _, Attribute attribute) =>
+      : _attributes.map<String, dynamic>((_, attribute) =>
           MapEntry<String, dynamic>(attribute.key, attribute.value));
 
   Iterable<String> get keys => _attributes.keys;
@@ -47,7 +48,7 @@ class Style {
   bool containsKey(String key) => _attributes.containsKey(key);
 
   Attribute? getBlockExceptHeader() {
-    for (Attribute val in values) {
+    for (final val in values) {
       if (val.isBlockExceptHeader) {
         return val;
       }
@@ -56,7 +57,7 @@ class Style {
   }
 
   Style merge(Attribute attribute) {
-    Map<String, Attribute> merged = Map<String, Attribute>.from(_attributes);
+    final merged = Map<String, Attribute>.from(_attributes);
     if (attribute.value == null) {
       merged.remove(attribute.key);
     } else {
@@ -66,21 +67,21 @@ class Style {
   }
 
   Style mergeAll(Style other) {
-    Style result = Style.attr(_attributes);
+    var result = Style.attr(_attributes);
-    for (Attribute attribute in other.values) {
+    for (final attribute in other.values) {
       result = result.merge(attribute);
     }
     return result;
   }
 
   Style removeAll(Set<Attribute> attributes) {
-    Map<String, Attribute> merged = Map<String, Attribute>.from(_attributes);
+    final merged = Map<String, Attribute>.from(_attributes);
     attributes.map((item) => item.key).forEach(merged.remove);
     return Style.attr(merged);
   }
 
   Style put(Attribute attribute) {
-    Map<String, Attribute> m = Map<String, Attribute>.from(attributes);
+    final m = Map<String, Attribute>.from(attributes);
     m[attribute.key] = attribute;
     return Style.attr(m);
   }
@@ -93,8 +94,8 @@ class Style {
     if (other is! Style) {
       return false;
     }
-    Style typedOther = other;
+    final typedOther = other;
-    final eq = const MapEquality<String, Attribute>();
+    const eq = MapEquality<String, Attribute>();
     return eq.equals(_attributes, typedOther._attributes);
   }
 

lib/models/quill_delta.dart

@@ -22,6 +22,29 @@ Object? _passThroughDataDecoder(Object? data) => data;
 
 /// Operation performed on a rich-text document.
 class Operation {
+  Operation._(this.key, this.length, this.data, Map? attributes)
+      : assert(_validKeys.contains(key), 'Invalid operation key "$key".'),
+        assert(() {
+          if (key != Operation.insertKey) return true;
+          return data is String ? data.length == length : length == 1;
+        }(), 'Length of insert operation must be equal to the data length.'),
+        _attributes =
+            attributes != null ? Map<String, dynamic>.from(attributes) : null;
+
+  /// Creates operation which deletes [length] of characters.
+  factory Operation.delete(int length) =>
+      Operation._(Operation.deleteKey, length, '', null);
+
+  /// Creates operation which inserts [text] with optional [attributes].
+  factory Operation.insert(dynamic data, [Map<String, dynamic>? attributes]) =>
+      Operation._(Operation.insertKey, data is String ? data.length : 1, data,
+          attributes);
+
+  /// Creates operation which retains [length] of characters and optionally
+  /// applies attributes.
+  factory Operation.retain(int? length, [Map<String, dynamic>? attributes]) =>
+      Operation._(Operation.retainKey, length, '', attributes);
+
   /// Key of insert operations.
   static const String insertKey = 'insert';
 
@@ -50,15 +73,6 @@ class Operation {
       _attributes == null ? null : Map<String, dynamic>.from(_attributes!);
   final Map<String, dynamic>? _attributes;
 
-  Operation._(this.key, this.length, this.data, Map? attributes)
-      : assert(_validKeys.contains(key), 'Invalid operation key "$key".'),
-        assert(() {
-          if (key != Operation.insertKey) return true;
-          return data is String ? data.length == length : length == 1;
-        }(), 'Length of insert operation must be equal to the data length.'),
-        _attributes =
-            attributes != null ? Map<String, dynamic>.from(attributes) : null;
-
   /// Creates new [Operation] from JSON payload.
   ///
   /// If `dataDecoder` parameter is not null then it is used to additionally
@@ -89,20 +103,6 @@ class Operation {
     return json;
   }
 
-  /// Creates operation which deletes [length] of characters.
-  factory Operation.delete(int length) =>
-      Operation._(Operation.deleteKey, length, '', null);
-
-  /// Creates operation which inserts [text] with optional [attributes].
-  factory Operation.insert(dynamic data, [Map<String, dynamic>? attributes]) =>
-      Operation._(Operation.insertKey, data is String ? data.length : 1, data,
-          attributes);
-
-  /// Creates operation which retains [length] of characters and optionally
-  /// applies attributes.
-  factory Operation.retain(int? length, [Map<String, dynamic>? attributes]) =>
-      Operation._(Operation.retainKey, length, '', attributes);
-
   /// Returns value of this operation.
   ///
   /// For insert operations this returns text, for delete and retain - length.
@@ -135,7 +135,7 @@ class Operation {
   bool operator ==(other) {
     if (identical(this, other)) return true;
     if (other is! Operation) return false;
-    Operation typedOther = other;
+    final typedOther = other;
     return key == typedOther.key &&
         length == typedOther.length &&
         _valueEquality.equals(data, typedOther.data) &&
@@ -180,6 +180,15 @@ class Operation {
 /// "document delta". When delta includes also "retain" or "delete" operations
 /// it is a "change delta".
 class Delta {
+  /// Creates new empty [Delta].
+  factory Delta() => Delta._(<Operation>[]);
+
+  Delta._(List<Operation> operations) : _operations = operations;
+
+  /// Creates new [Delta] from [other].
+  factory Delta.from(Delta other) =>
+      Delta._(List<Operation>.from(other._operations));
+
   /// Transforms two attribute sets.
   static Map<String, dynamic>? transformAttributes(
       Map<String, dynamic>? a, Map<String, dynamic>? b, bool priority) {
@@ -221,14 +230,14 @@ class Delta {
     attr ??= const {};
     base ??= const {};
 
-    var baseInverted = base.keys.fold({}, (dynamic memo, key) {
+    final baseInverted = base.keys.fold({}, (dynamic memo, key) {
       if (base![key] != attr![key] && attr.containsKey(key)) {
         memo[key] = base[key];
       }
       return memo;
     });
 
-    var inverted =
+    final inverted =
         Map<String, dynamic>.from(attr.keys.fold(baseInverted, (memo, key) {
       if (base![key] != attr![key] && !base.containsKey(key)) {
         memo[key] = null;
@@ -242,15 +251,6 @@ class Delta {
 
   int _modificationCount = 0;
 
-  Delta._(List<Operation> operations) : _operations = operations;
-
-  /// Creates new empty [Delta].
-  factory Delta() => Delta._(<Operation>[]);
-
-  /// Creates new [Delta] from [other].
-  factory Delta.from(Delta other) =>
-      Delta._(List<Operation>.from(other._operations));
-
   /// Creates [Delta] from de-serialized JSON representation.
   ///
   /// If `dataDecoder` parameter is not null then it is used to additionally
@@ -292,9 +292,8 @@ class Delta {
   bool operator ==(dynamic other) {
     if (identical(this, other)) return true;
     if (other is! Delta) return false;
-    Delta typedOther = other;
+    final typedOther = other;
-    final comparator =
+    const comparator = ListEquality<Operation>(DefaultEquality<Operation>());
-        const ListEquality<Operation>(DefaultEquality<Operation>());
     return comparator.equals(_operations, typedOther._operations);
   }
 
@@ -529,7 +528,8 @@ class Delta {
           if (op.isDelete) {
             inverted.push(baseOp);
           } else if (op.isRetain && op.isNotPlain) {
-            var invertAttr = invertAttributes(op.attributes, baseOp.attributes);
+            final invertAttr =
+                invertAttributes(op.attributes, baseOp.attributes);
             inverted.retain(
                 baseOp.length!, invertAttr.isEmpty ? null : invertAttr);
           }
@@ -548,7 +548,7 @@ class Delta {
   Delta slice(int start, [int? end]) {
     final delta = Delta();
     var index = 0;
-    var opIterator = DeltaIterator(this);
+    final opIterator = DeltaIterator(this);
 
     final actualEnd = end ?? double.infinity;
 
@@ -599,13 +599,13 @@ class Delta {
 
 /// Specialized iterator for [Delta]s.
 class DeltaIterator {
+  DeltaIterator(this.delta) : _modificationCount = delta._modificationCount;
+
   final Delta delta;
   final int _modificationCount;
   int _index = 0;
   num _offset = 0;
 
-  DeltaIterator(this.delta) : _modificationCount = delta._modificationCount;
-
   bool get isNextInsert => nextOperationKey == Operation.insertKey;
 
   bool get isNextDelete => nextOperationKey == Operation.deleteKey;
@@ -661,7 +661,7 @@ class DeltaIterator {
       final opIsNotEmpty =
           opData is String ? opData.isNotEmpty : true; // embeds are never empty
       final opLength = opData is String ? opData.length : 1;
-      final int opActualLength = opIsNotEmpty ? opLength : actualLength as int;
+      final opActualLength = opIsNotEmpty ? opLength : actualLength as int;
       return Operation._(opKey, opActualLength, opData, opAttributes);
     }
     return Operation.retain(length);

lib/models/rules/delete.dart

@@ -1,6 +1,6 @@
-import 'package:flutter_quill/models/documents/attribute.dart';
+import '../documents/attribute.dart';
-import 'package:flutter_quill/models/quill_delta.dart';
+import '../quill_delta.dart';
-import 'package:flutter_quill/models/rules/rule.dart';
+import 'rule.dart';
 
 abstract class DeleteRule extends Rule {
   const DeleteRule();
@@ -34,34 +34,33 @@ class PreserveLineStyleOnMergeRule extends DeleteRule {
   @override
   Delta? applyRule(Delta document, int index,
       {int? len, Object? data, Attribute? attribute}) {
-    DeltaIterator itr = DeltaIterator(document);
+    final itr = DeltaIterator(document)..skip(index);
-    itr.skip(index);
+    var op = itr.next(1);
-    Operation op = itr.next(1);
     if (op.data != '\n') {
       return null;
     }
 
-    bool isNotPlain = op.isNotPlain;
+    final isNotPlain = op.isNotPlain;
-    Map<String, dynamic>? attrs = op.attributes;
+    final attrs = op.attributes;
 
     itr.skip(len! - 1);
-    Delta delta = Delta()
+    final delta = Delta()
       ..retain(index)
       ..delete(len);
 
     while (itr.hasNext) {
       op = itr.next();
-      String text = op.data is String ? (op.data as String?)! : '';
+      final text = op.data is String ? (op.data as String?)! : '';
-      int lineBreak = text.indexOf('\n');
+      final lineBreak = text.indexOf('\n');
       if (lineBreak == -1) {
         delta.retain(op.length!);
         continue;
       }
 
-      Map<String, dynamic>? attributes = op.attributes == null
+      var attributes = op.attributes == null
           ? null
-          : op.attributes!.map<String, dynamic>((String key, dynamic value) =>
+          : op.attributes!.map<String, dynamic>(
-              MapEntry<String, dynamic>(key, null));
+              (key, dynamic value) => MapEntry<String, dynamic>(key, null));
 
       if (isNotPlain) {
         attributes ??= <String, dynamic>{};
@@ -80,15 +79,15 @@ class EnsureEmbedLineRule extends DeleteRule {
   @override
   Delta? applyRule(Delta document, int index,
       {int? len, Object? data, Attribute? attribute}) {
-    DeltaIterator itr = DeltaIterator(document);
+    final itr = DeltaIterator(document);
 
-    Operation? op = itr.skip(index);
+    var op = itr.skip(index);
     int? indexDelta = 0, lengthDelta = 0, remain = len;
-    bool embedFound = op != null && op.data is! String;
+    var embedFound = op != null && op.data is! String;
-    bool hasLineBreakBefore =
+    final hasLineBreakBefore =
         !embedFound && (op == null || (op.data as String).endsWith('\n'));
     if (embedFound) {
-      Operation candidate = itr.next(1);
+      var candidate = itr.next(1);
       if (remain != null) {
         remain--;
         if (candidate.data == '\n') {
@@ -107,7 +106,7 @@ class EnsureEmbedLineRule extends DeleteRule {
     op = itr.skip(remain!);
     if (op != null &&
         (op.data is String ? op.data as String? : '')!.endsWith('\n')) {
-      Operation candidate = itr.next(1);
+      final candidate = itr.next(1);
       if (candidate.data is! String && !hasLineBreakBefore) {
         embedFound = true;
         lengthDelta--;

lib/models/rules/format.dart

@@ -1,6 +1,6 @@
-import 'package:flutter_quill/models/documents/attribute.dart';
+import '../documents/attribute.dart';
-import 'package:flutter_quill/models/quill_delta.dart';
+import '../quill_delta.dart';
-import 'package:flutter_quill/models/rules/rule.dart';
+import 'rule.dart';
 
 abstract class FormatRule extends Rule {
   const FormatRule();
@@ -26,21 +26,20 @@ class ResolveLineFormatRule extends FormatRule {
       return null;
     }
 
-    Delta delta = Delta()..retain(index);
+    var delta = Delta()..retain(index);
-    DeltaIterator itr = DeltaIterator(document);
+    final itr = DeltaIterator(document)..skip(index);
-    itr.skip(index);
     Operation op;
-    for (int cur = 0; cur < len! && itr.hasNext; cur += op.length!) {
+    for (var cur = 0; cur < len! && itr.hasNext; cur += op.length!) {
       op = itr.next(len - cur);
       if (op.data is! String || !(op.data as String).contains('\n')) {
         delta.retain(op.length!);
         continue;
       }
-      String text = op.data as String;
+      final text = op.data as String;
-      Delta tmp = Delta();
+      final tmp = Delta();
-      int offset = 0;
+      var offset = 0;
 
-      for (int lineBreak = text.indexOf('\n');
+      for (var lineBreak = text.indexOf('\n');
           lineBreak >= 0;
           lineBreak = text.indexOf('\n', offset)) {
         tmp..retain(lineBreak - offset)..retain(1, attribute.toJson());
@@ -52,8 +51,8 @@ class ResolveLineFormatRule extends FormatRule {
 
     while (itr.hasNext) {
       op = itr.next();
-      String text = op.data is String ? (op.data as String?)! : '';
+      final text = op.data is String ? (op.data as String?)! : '';
-      int lineBreak = text.indexOf('\n');
+      final lineBreak = text.indexOf('\n');
       if (lineBreak < 0) {
         delta.retain(op.length!);
         continue;
@@ -75,9 +74,9 @@ class FormatLinkAtCaretPositionRule extends FormatRule {
       return null;
     }
 
-    Delta delta = Delta();
+    final delta = Delta();
-    DeltaIterator itr = DeltaIterator(document);
+    final itr = DeltaIterator(document);
-    Operation? before = itr.skip(index), after = itr.next();
+    final before = itr.skip(index), after = itr.next();
     int? beg = index, retain = 0;
     if (before != null && before.hasAttribute(attribute.key)) {
       beg -= before.length!;
@@ -105,20 +104,19 @@ class ResolveInlineFormatRule extends FormatRule {
       return null;
     }
 
-    Delta delta = Delta()..retain(index);
+    final delta = Delta()..retain(index);
-    DeltaIterator itr = DeltaIterator(document);
+    final itr = DeltaIterator(document)..skip(index);
-    itr.skip(index);
 
     Operation op;
-    for (int cur = 0; cur < len! && itr.hasNext; cur += op.length!) {
+    for (var cur = 0; cur < len! && itr.hasNext; cur += op.length!) {
       op = itr.next(len - cur);
-      String text = op.data is String ? (op.data as String?)! : '';
+      final text = op.data is String ? (op.data as String?)! : '';
-      int lineBreak = text.indexOf('\n');
+      var lineBreak = text.indexOf('\n');
       if (lineBreak < 0) {
         delta.retain(op.length!, attribute.toJson());
         continue;
       }
-      int pos = 0;
+      var pos = 0;
       while (lineBreak >= 0) {
         delta..retain(lineBreak - pos, attribute.toJson())..retain(1);
         pos = lineBreak + 1;

lib/models/rules/insert.dart

@@ -1,9 +1,10 @@
-import 'package:flutter_quill/models/documents/attribute.dart';
-import 'package:flutter_quill/models/documents/style.dart';
-import 'package:flutter_quill/models/quill_delta.dart';
-import 'package:flutter_quill/models/rules/rule.dart';
 import 'package:tuple/tuple.dart';
 
+import '../documents/attribute.dart';
+import '../documents/style.dart';
+import '../quill_delta.dart';
+import 'rule.dart';
+
 abstract class InsertRule extends Rule {
   const InsertRule();
 
@@ -28,28 +29,28 @@ class PreserveLineStyleOnSplitRule extends InsertRule {
       return null;
     }
 
-    DeltaIterator itr = DeltaIterator(document);
+    final itr = DeltaIterator(document);
-    Operation? before = itr.skip(index);
+    final before = itr.skip(index);
     if (before == null ||
         before.data is! String ||
         (before.data as String).endsWith('\n')) {
       return null;
     }
-    Operation after = itr.next();
+    final after = itr.next();
     if (after.data is! String || (after.data as String).startsWith('\n')) {
       return null;
     }
 
     final text = after.data as String;
 
-    Delta delta = Delta()..retain(index);
+    final delta = Delta()..retain(index);
     if (text.contains('\n')) {
       assert(after.isPlain);
       delta.insert('\n');
       return delta;
     }
-    Tuple2<Operation?, int?> nextNewLine = _getNextNewLine(itr);
+    final nextNewLine = _getNextNewLine(itr);
-    Map<String, dynamic>? attributes = nextNewLine.item1?.attributes;
+    final attributes = nextNewLine.item1?.attributes;
 
     return delta..insert('\n', attributes);
   }
@@ -65,19 +66,18 @@ class PreserveBlockStyleOnInsertRule extends InsertRule {
       return null;
     }
 
-    DeltaIterator itr = DeltaIterator(document);
+    final itr = DeltaIterator(document)..skip(index);
-    itr.skip(index);
 
-    Tuple2<Operation?, int?> nextNewLine = _getNextNewLine(itr);
+    final nextNewLine = _getNextNewLine(itr);
-    Style lineStyle =
+    final lineStyle =
         Style.fromJson(nextNewLine.item1?.attributes ?? <String, dynamic>{});
 
-    Attribute? attribute = lineStyle.getBlockExceptHeader();
+    final attribute = lineStyle.getBlockExceptHeader();
     if (attribute == null) {
       return null;
     }
 
-    var blockStyle = <String, dynamic>{attribute.key: attribute.value};
+    final blockStyle = <String, dynamic>{attribute.key: attribute.value};
 
     Map<String, dynamic>? resetStyle;
 
@@ -85,10 +85,10 @@ class PreserveBlockStyleOnInsertRule extends InsertRule {
       resetStyle = Attribute.header.toJson();
     }
 
-    List<String> lines = data.split('\n');
+    final lines = data.split('\n');
-    Delta delta = Delta()..retain(index);
+    final delta = Delta()..retain(index);
-    for (int i = 0; i < lines.length; i++) {
+    for (var i = 0; i < lines.length; i++) {
-      String line = lines[i];
+      final line = lines[i];
       if (line.isNotEmpty) {
         delta.insert(line);
       }
@@ -100,8 +100,8 @@ class PreserveBlockStyleOnInsertRule extends InsertRule {
     }
 
     if (resetStyle != null) {
-      delta.retain(nextNewLine.item2!);
       delta
+        ..retain(nextNewLine.item2!)
         ..retain((nextNewLine.item1!.data as String).indexOf('\n'))
         ..retain(1, resetStyle);
     }
@@ -130,10 +130,9 @@ class AutoExitBlockRule extends InsertRule {
       return null;
     }
 
-    DeltaIterator itr = DeltaIterator(document);
+    final itr = DeltaIterator(document);
-    Operation? prev = itr.skip(index), cur = itr.next();
+    final prev = itr.skip(index), cur = itr.next();
-    Attribute? blockStyle =
+    final blockStyle = Style.fromJson(cur.attributes).getBlockExceptHeader();
-        Style.fromJson(cur.attributes).getBlockExceptHeader();
     if (cur.isPlain || blockStyle == null) {
       return null;
     }
@@ -145,7 +144,7 @@ class AutoExitBlockRule extends InsertRule {
       return null;
     }
 
-    Tuple2<Operation?, int?> nextNewLine = _getNextNewLine(itr);
+    final nextNewLine = _getNextNewLine(itr);
     if (nextNewLine.item1 != null &&
         nextNewLine.item1!.attributes != null &&
         Style.fromJson(nextNewLine.item1!.attributes).getBlockExceptHeader() ==
@@ -154,7 +153,7 @@ class AutoExitBlockRule extends InsertRule {
     }
 
     final attributes = cur.attributes ?? <String, dynamic>{};
-    String k = attributes.keys
+    final k = attributes.keys
         .firstWhere((k) => Attribute.blockKeysExceptHeader.contains(k));
     attributes[k] = null;
     // retain(1) should be '\n', set it with no attribute
@@ -172,9 +171,8 @@ class ResetLineFormatOnNewLineRule extends InsertRule {
       return null;
     }
 
-    DeltaIterator itr = DeltaIterator(document);
+    final itr = DeltaIterator(document)..skip(index);
-    itr.skip(index);
+    final cur = itr.next();
-    Operation cur = itr.next();
     if (cur.data is! String || !(cur.data as String).startsWith('\n')) {
       return null;
     }
@@ -202,12 +200,12 @@ class InsertEmbedsRule extends InsertRule {
       return null;
     }
 
-    Delta delta = Delta()..retain(index);
+    final delta = Delta()..retain(index);
-    DeltaIterator itr = DeltaIterator(document);
+    final itr = DeltaIterator(document);
-    Operation? prev = itr.skip(index), cur = itr.next();
+    final prev = itr.skip(index), cur = itr.next();
 
-    String? textBefore = prev?.data is String ? prev!.data as String? : '';
+    final textBefore = prev?.data is String ? prev!.data as String? : '';
-    String textAfter = cur.data is String ? (cur.data as String?)! : '';
+    final textAfter = cur.data is String ? (cur.data as String?)! : '';
 
     final isNewlineBefore = prev == null || textBefore!.endsWith('\n');
     final isNewlineAfter = textAfter.startsWith('\n');
@@ -221,7 +219,7 @@ class InsertEmbedsRule extends InsertRule {
       lineStyle = cur.attributes;
     } else {
       while (itr.hasNext) {
-        Operation op = itr.next();
+        final op = itr.next();
         if ((op.data is String ? op.data as String? : '')!.contains('\n')) {
           lineStyle = op.attributes;
           break;
@@ -250,17 +248,17 @@ class ForceNewlineForInsertsAroundEmbedRule extends InsertRule {
       return null;
     }
 
-    String text = data;
+    final text = data;
-    DeltaIterator itr = DeltaIterator(document);
+    final itr = DeltaIterator(document);
     final prev = itr.skip(index);
     final cur = itr.next();
-    bool cursorBeforeEmbed = cur.data is! String;
+    final cursorBeforeEmbed = cur.data is! String;
-    bool cursorAfterEmbed = prev != null && prev.data is! String;
+    final cursorAfterEmbed = prev != null && prev.data is! String;
 
     if (!cursorBeforeEmbed && !cursorAfterEmbed) {
       return null;
     }
-    Delta delta = Delta()..retain(index);
+    final delta = Delta()..retain(index);
     if (cursorBeforeEmbed && !text.endsWith('\n')) {
       return delta..insert(text)..insert('\n');
     }
@@ -281,19 +279,19 @@ class AutoFormatLinksRule extends InsertRule {
       return null;
     }
 
-    DeltaIterator itr = DeltaIterator(document);
+    final itr = DeltaIterator(document);
-    Operation? prev = itr.skip(index);
+    final prev = itr.skip(index);
     if (prev == null || prev.data is! String) {
       return null;
     }
 
     try {
-      String cand = (prev.data as String).split('\n').last.split(' ').last;
+      final cand = (prev.data as String).split('\n').last.split(' ').last;
-      Uri link = Uri.parse(cand);
+      final link = Uri.parse(cand);
       if (!['https', 'http'].contains(link.scheme)) {
         return null;
       }
-      Map<String, dynamic> attributes = prev.attributes ?? <String, dynamic>{};
+      final attributes = prev.attributes ?? <String, dynamic>{};
 
       if (attributes.containsKey(Attribute.link.key)) {
         return null;
@@ -320,16 +318,16 @@ class PreserveInlineStylesRule extends InsertRule {
       return null;
     }
 
-    DeltaIterator itr = DeltaIterator(document);
+    final itr = DeltaIterator(document);
-    Operation? prev = itr.skip(index);
+    final prev = itr.skip(index);
     if (prev == null ||
         prev.data is! String ||
         (prev.data as String).contains('\n')) {
       return null;
     }
 
-    Map<String, dynamic>? attributes = prev.attributes;
+    final attributes = prev.attributes;
-    String text = data;
+    final text = data;
     if (attributes == null || !attributes.containsKey(Attribute.link.key)) {
       return Delta()
         ..retain(index)
@@ -337,13 +335,12 @@ class PreserveInlineStylesRule extends InsertRule {
     }
 
     attributes.remove(Attribute.link.key);
-    Delta delta = Delta()
+    final delta = Delta()
       ..retain(index)
       ..insert(text, attributes.isEmpty ? null : attributes);
-    Operation next = itr.next();
+    final next = itr.next();
 
-    Map<String, dynamic> nextAttributes =
+    final nextAttributes = next.attributes ?? const <String, dynamic>{};
-        next.attributes ?? const <String, dynamic>{};
     if (!nextAttributes.containsKey(Attribute.link.key)) {
       return delta;
     }
@@ -370,9 +367,9 @@ class CatchAllInsertRule extends InsertRule {
 
 Tuple2<Operation?, int?> _getNextNewLine(DeltaIterator iterator) {
   Operation op;
-  for (int skipped = 0; iterator.hasNext; skipped += op.length!) {
+  for (var skipped = 0; iterator.hasNext; skipped += op.length!) {
     op = iterator.next();
-    int lineBreak =
+    final lineBreak =
         (op.data is String ? op.data as String? : '')!.indexOf('\n');
     if (lineBreak >= 0) {
       return Tuple2(op, skipped);

lib/models/rules/rule.dart

@@ -1,7 +1,6 @@
-import 'package:flutter_quill/models/documents/attribute.dart';
+import '../documents/attribute.dart';
-import 'package:flutter_quill/models/documents/document.dart';
+import '../documents/document.dart';
-import 'package:flutter_quill/models/quill_delta.dart';
+import '../quill_delta.dart';
-
 import 'delete.dart';
 import 'format.dart';
 import 'insert.dart';
@@ -27,6 +26,8 @@ abstract class Rule {
 }
 
 class Rules {
+  Rules(this._rules);
+
   final List<Rule> _rules;
   static final Rules _instance = Rules([
     const FormatLinkAtCaretPositionRule(),
@@ -46,14 +47,12 @@ class Rules {
     const CatchAllDeleteRule(),
   ]);
 
-  Rules(this._rules);
-
   static Rules getInstance() => _instance;
 
   Delta apply(RuleType ruleType, Document document, int index,
       {int? len, Object? data, Attribute? attribute}) {
     final delta = document.toDelta();
-    for (var rule in _rules) {
+    for (final rule in _rules) {
       if (rule.type != ruleType) {
         continue;
       }

lib/utils/color.dart

@@ -118,8 +118,8 @@ Color stringToColor(String? s) {
     throw 'Color code not supported';
   }
 
-  String hex = s.replaceFirst('#', '');
+  var hex = s.replaceFirst('#', '');
-  hex = hex.length == 6 ? 'ff' + hex : hex;
+  hex = hex.length == 6 ? 'ff$hex' : hex;
-  int val = int.parse(hex, radix: 16);
+  final val = int.parse(hex, radix: 16);
   return Color(val);
 }

lib/utils/diff_delta.dart

@@ -1,6 +1,6 @@
 import 'dart:math' as math;
 
-import 'package:flutter_quill/models/quill_delta.dart';
+import '../models/quill_delta.dart';
 
 const Set<int> WHITE_SPACE = {
   0x9,
@@ -33,6 +33,8 @@ const Set<int> WHITE_SPACE = {
 
 // Diff between two texts - old text and new text
 class Diff {
+  Diff(this.start, this.deleted, this.inserted);
+
   // Start index in old text at which changes begin.
   final int start;
 
@@ -42,8 +44,6 @@ class Diff {
   // The inserted text
   final String inserted;
 
-  Diff(this.start, this.deleted, this.inserted);
-
   @override
   String toString() {
     return 'Diff[$start, "$deleted", "$inserted"]';
@@ -52,17 +52,17 @@ class Diff {
 
 /* Get diff operation between old text and new text */
 Diff getDiff(String oldText, String newText, int cursorPosition) {
-  int end = oldText.length;
+  var end = oldText.length;
-  int delta = newText.length - end;
+  final delta = newText.length - end;
-  for (int limit = math.max(0, cursorPosition - delta);
+  for (final limit = math.max(0, cursorPosition - delta);
       end > limit && oldText[end - 1] == newText[end + delta - 1];
       end--) {}
-  int start = 0;
+  var start = 0;
-  for (int startLimit = cursorPosition - math.max(0, delta);
+  for (final startLimit = cursorPosition - math.max(0, delta);
       start < startLimit && oldText[start] == newText[start];
       start++) {}
-  String deleted = (start >= end) ? '' : oldText.substring(start, end);
+  final deleted = (start >= end) ? '' : oldText.substring(start, end);
-  String inserted = newText.substring(start, end + delta);
+  final inserted = newText.substring(start, end + delta);
   return Diff(start, deleted, inserted);
 }
 
@@ -71,19 +71,15 @@ int getPositionDelta(Delta user, Delta actual) {
     return 0;
   }
 
-  DeltaIterator userItr = DeltaIterator(user);
+  final userItr = DeltaIterator(user);
-  DeltaIterator actualItr = DeltaIterator(actual);
+  final actualItr = DeltaIterator(actual);
-  int diff = 0;
+  var diff = 0;
   while (userItr.hasNext || actualItr.hasNext) {
     final length = math.min(userItr.peekLength(), actualItr.peekLength());
-    Operation userOperation = userItr.next(length as int);
+    final userOperation = userItr.next(length as int);
-    Operation actualOperation = actualItr.next(length);
+    final actualOperation = actualItr.next(length);
     if (userOperation.length != actualOperation.length) {
-      throw 'userOp ' +
+      throw 'userOp ${userOperation.length} does not match  actualOp ${actualOperation.length}';
-          userOperation.length.toString() +
-          ' does not match ' +
-          ' actualOp ' +
-          actualOperation.length.toString();
     }
     if (userOperation.key == actualOperation.key) {
       continue;

lib/widgets/box.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/rendering.dart';
-import 'package:flutter_quill/models/documents/nodes/container.dart';
+
+import '../models/documents/nodes/container.dart';
 
 abstract class RenderContentProxyBox implements RenderBox {
   double getPreferredLineHeight();

lib/widgets/controller.dart

@@ -1,19 +1,16 @@
 import 'dart:math' as math;
 
 import 'package:flutter/cupertino.dart';
-import 'package:flutter_quill/models/documents/attribute.dart';
-import 'package:flutter_quill/models/documents/document.dart';
-import 'package:flutter_quill/models/documents/nodes/embed.dart';
-import 'package:flutter_quill/models/documents/style.dart';
-import 'package:flutter_quill/models/quill_delta.dart';
-import 'package:flutter_quill/utils/diff_delta.dart';
 import 'package:tuple/tuple.dart';
 
-class QuillController extends ChangeNotifier {
+import '../models/documents/attribute.dart';
-  final Document document;
+import '../models/documents/document.dart';
-  TextSelection selection;
+import '../models/documents/nodes/embed.dart';
-  Style toggledStyle = Style();
+import '../models/documents/style.dart';
+import '../models/quill_delta.dart';
+import '../utils/diff_delta.dart';
 
+class QuillController extends ChangeNotifier {
   QuillController({required this.document, required this.selection});
 
   factory QuillController.basic() {
@@ -23,6 +20,10 @@ class QuillController extends ChangeNotifier {
     );
   }
 
+  final Document document;
+  TextSelection selection;
+  Style toggledStyle = Style();
+
   // item1: Document state before [change].
   //
   // item2: Change delta applied to the document.
@@ -42,7 +43,7 @@ class QuillController extends ChangeNotifier {
   }
 
   void undo() {
-    Tuple2 tup = document.undo();
+    final tup = document.undo();
     if (tup.item1) {
       _handleHistoryChange(tup.item2);
     }
@@ -64,7 +65,7 @@ class QuillController extends ChangeNotifier {
   }
 
   void redo() {
-    Tuple2 tup = document.redo();
+    final tup = document.redo();
     if (tup.item1) {
       _handleHistoryChange(tup.item2);
     }
@@ -81,7 +82,7 @@ class QuillController extends ChangeNotifier {
     Delta? delta;
     if (len > 0 || data is! String || data.isNotEmpty) {
       delta = document.replace(index, len, data);
-      bool shouldRetainDelta = toggledStyle.isNotEmpty &&
+      var shouldRetainDelta = toggledStyle.isNotEmpty &&
           delta.isNotEmpty &&
           delta.length <= 2 &&
           delta.last.isInsert;
@@ -97,7 +98,7 @@ class QuillController extends ChangeNotifier {
         }
       }
       if (shouldRetainDelta) {
-        Delta retainDelta = Delta()
+        final retainDelta = Delta()
           ..retain(index)
           ..retain(data is String ? data.length : 1, toggledStyle.toJson());
         document.compose(retainDelta, ChangeSource.LOCAL);
@@ -109,11 +110,11 @@ class QuillController extends ChangeNotifier {
       if (delta == null || delta.isEmpty) {
         _updateSelection(textSelection, ChangeSource.LOCAL);
       } else {
-        Delta user = Delta()
+        final user = Delta()
           ..retain(index)
           ..insert(data)
           ..delete(len);
-        int positionDelta = getPositionDelta(user, delta);
+        final positionDelta = getPositionDelta(user, delta);
         _updateSelection(
           textSelection.copyWith(
             baseOffset: textSelection.baseOffset + positionDelta,
@@ -133,8 +134,8 @@ class QuillController extends ChangeNotifier {
       toggledStyle = toggledStyle.put(attribute);
     }
 
-    Delta change = document.format(index, len, attribute);
+    final change = document.format(index, len, attribute);
-    TextSelection adjustedSelection = selection.copyWith(
+    final adjustedSelection = selection.copyWith(
         baseOffset: change.transformPosition(selection.baseOffset),
         extentOffset: change.transformPosition(selection.extentOffset));
     if (selection != adjustedSelection) {
@@ -176,7 +177,7 @@ class QuillController extends ChangeNotifier {
 
   void _updateSelection(TextSelection textSelection, ChangeSource source) {
     selection = textSelection;
-    int end = document.length - 1;
+    final end = document.length - 1;
     selection = selection.copyWith(
         baseOffset: math.min(selection.baseOffset, end),
         extentOffset: math.min(selection.extentOffset, end));

lib/widgets/cursor.dart

@@ -8,15 +8,6 @@ import 'box.dart';
 const Duration _FADE_DURATION = Duration(milliseconds: 250);
 
 class CursorStyle {
-  final Color color;
-  final Color backgroundColor;
-  final double width;
-  final double? height;
-  final Radius? radius;
-  final Offset? offset;
-  final bool opacityAnimates;
-  final bool paintAboveText;
-
   const CursorStyle({
     required this.color,
     required this.backgroundColor,
@@ -28,6 +19,15 @@ class CursorStyle {
     this.paintAboveText = false,
   });
 
+  final Color color;
+  final Color backgroundColor;
+  final double width;
+  final double? height;
+  final Radius? radius;
+  final Offset? offset;
+  final bool opacityAnimates;
+  final bool paintAboveText;
+
   @override
   bool operator ==(Object other) =>
       identical(this, other) ||
@@ -55,20 +55,11 @@ class CursorStyle {
 }
 
 class CursorCont extends ChangeNotifier {
-  final ValueNotifier<bool> show;
-  final ValueNotifier<bool> _blink;
-  final ValueNotifier<Color> color;
-  late AnimationController _blinkOpacityCont;
-  Timer? _cursorTimer;
-  bool _targetCursorVisibility = false;
-  CursorStyle _style;
-
   CursorCont({
-    required ValueNotifier<bool> show,
+    required this.show,
     required CursorStyle style,
     required TickerProvider tickerProvider,
-  })   : show = show,
+  })   : _style = style,
-        _style = style,
         _blink = ValueNotifier(false),
         color = ValueNotifier(style.color) {
     _blinkOpacityCont =
@@ -76,6 +67,14 @@ class CursorCont extends ChangeNotifier {
     _blinkOpacityCont.addListener(_onColorTick);
   }
 
+  final ValueNotifier<bool> show;
+  final ValueNotifier<bool> _blink;
+  final ValueNotifier<Color> color;
+  late AnimationController _blinkOpacityCont;
+  Timer? _cursorTimer;
+  bool _targetCursorVisibility = false;
+  CursorStyle _style;
+
   ValueNotifier<bool> get cursorBlink => _blink;
 
   ValueNotifier<Color> get cursorColor => color;
@@ -99,7 +98,7 @@ class CursorCont extends ChangeNotifier {
 
   void _cursorTick(Timer timer) {
     _targetCursorVisibility = !_targetCursorVisibility;
-    double targetOpacity = _targetCursorVisibility ? 1.0 : 0.0;
+    final targetOpacity = _targetCursorVisibility ? 1.0 : 0.0;
     if (style.opacityAnimates) {
       _blinkOpacityCont.animateTo(targetOpacity, curve: Curves.easeOut);
     } else {
@@ -133,8 +132,9 @@ class CursorCont extends ChangeNotifier {
     _blinkOpacityCont.value = 0.0;
 
     if (style.opacityAnimates) {
-      _blinkOpacityCont.stop();
+      _blinkOpacityCont
-      _blinkOpacityCont.value = 0.0;
+        ..stop()
+        ..value = 0.0;
     }
   }
 
@@ -156,30 +156,30 @@ class CursorCont extends ChangeNotifier {
 }
 
 class CursorPainter {
+  CursorPainter(this.editable, this.style, this.prototype, this.color,
+      this.devicePixelRatio);
+
   final RenderContentProxyBox? editable;
   final CursorStyle style;
   final Rect? prototype;
   final Color color;
   final double devicePixelRatio;
 
-  CursorPainter(this.editable, this.style, this.prototype, this.color,
-      this.devicePixelRatio);
-
   void paint(Canvas canvas, Offset offset, TextPosition position) {
     assert(prototype != null);
 
-    Offset caretOffset =
+    final caretOffset =
         editable!.getOffsetForCaret(position, prototype) + offset;
-    Rect caretRect = prototype!.shift(caretOffset);
+    var caretRect = prototype!.shift(caretOffset);
     if (style.offset != null) {
       caretRect = caretRect.shift(style.offset!);
     }
 
     if (caretRect.left < 0.0) {
-      caretRect = caretRect.shift(Offset(-caretRect.left, 0.0));
+      caretRect = caretRect.shift(Offset(-caretRect.left, 0));
     }
 
-    double? caretHeight = editable!.getFullHeightForCaret(position);
+    final caretHeight = editable!.getFullHeightForCaret(position);
     if (caretHeight != null) {
       switch (defaultTargetPlatform) {
         case TargetPlatform.android:
@@ -207,8 +207,8 @@ class CursorPainter {
       }
     }
 
-    Offset caretPosition = editable!.localToGlobal(caretRect.topLeft);
+    final caretPosition = editable!.localToGlobal(caretRect.topLeft);
-    double pixelMultiple = 1.0 / devicePixelRatio;
+    final pixelMultiple = 1.0 / devicePixelRatio;
     caretRect = caretRect.shift(Offset(
         caretPosition.dx.isFinite
             ? (caretPosition.dx / pixelMultiple).round() * pixelMultiple -
@@ -219,13 +219,13 @@ class CursorPainter {
                 caretPosition.dy
             : caretPosition.dy));
 
-    Paint paint = Paint()..color = color;
+    final paint = Paint()..color = color;
     if (style.radius == null) {
       canvas.drawRect(caretRect, paint);
       return;
     }
 
-    RRect caretRRect = RRect.fromRectAndRadius(caretRect, style.radius!);
+    final caretRRect = RRect.fromRectAndRadius(caretRect, style.radius!);
     canvas.drawRRect(caretRRect, paint);
   }
 }

lib/widgets/default_styles.dart

@@ -3,21 +3,21 @@ import 'package:flutter/widgets.dart';
 import 'package:tuple/tuple.dart';
 
 class QuillStyles extends InheritedWidget {
-  final DefaultStyles data;
-
   const QuillStyles({
     required this.data,
     required Widget child,
     Key? key,
   }) : super(key: key, child: child);
 
+  final DefaultStyles data;
+
   @override
   bool updateShouldNotify(QuillStyles oldWidget) {
     return data != oldWidget.data;
   }
 
   static DefaultStyles? getStyles(BuildContext context, bool nullOk) {
-    var widget = context.dependOnInheritedWidgetOfExactType<QuillStyles>();
+    final widget = context.dependOnInheritedWidgetOfExactType<QuillStyles>();
     if (widget == null && nullOk) {
       return null;
     }
@@ -27,6 +27,13 @@ class QuillStyles extends InheritedWidget {
 }
 
 class DefaultTextBlockStyle {
+  DefaultTextBlockStyle(
+    this.style,
+    this.verticalSpacing,
+    this.lineSpacing,
+    this.decoration,
+  );
+
   final TextStyle style;
 
   final Tuple2<double, double> verticalSpacing;
@@ -34,12 +41,32 @@ class DefaultTextBlockStyle {
   final Tuple2<double, double> lineSpacing;
 
   final BoxDecoration? decoration;
-
-  DefaultTextBlockStyle(
-      this.style, this.verticalSpacing, this.lineSpacing, this.decoration);
 }
 
 class DefaultStyles {
+  DefaultStyles({
+    this.h1,
+    this.h2,
+    this.h3,
+    this.paragraph,
+    this.bold,
+    this.italic,
+    this.underline,
+    this.strikeThrough,
+    this.link,
+    this.color,
+    this.placeHolder,
+    this.lists,
+    this.quote,
+    this.code,
+    this.indent,
+    this.align,
+    this.leading,
+    this.sizeSmall,
+    this.sizeLarge,
+    this.sizeHuge,
+  });
+
   final DefaultTextBlockStyle? h1;
   final DefaultTextBlockStyle? h2;
   final DefaultTextBlockStyle? h3;
@@ -61,36 +88,14 @@ class DefaultStyles {
   final DefaultTextBlockStyle? align;
   final DefaultTextBlockStyle? leading;
 
-  DefaultStyles(
-      {this.h1,
-      this.h2,
-      this.h3,
-      this.paragraph,
-      this.bold,
-      this.italic,
-      this.underline,
-      this.strikeThrough,
-      this.link,
-      this.color,
-      this.placeHolder,
-      this.lists,
-      this.quote,
-      this.code,
-      this.indent,
-      this.align,
-      this.leading,
-      this.sizeSmall,
-      this.sizeLarge,
-      this.sizeHuge});
-
   static DefaultStyles getInstance(BuildContext context) {
-    ThemeData themeData = Theme.of(context);
+    final themeData = Theme.of(context);
-    DefaultTextStyle defaultTextStyle = DefaultTextStyle.of(context);
+    final defaultTextStyle = DefaultTextStyle.of(context);
-    TextStyle baseStyle = defaultTextStyle.style.copyWith(
+    final baseStyle = defaultTextStyle.style.copyWith(
-      fontSize: 16.0,
+      fontSize: 16,
       height: 1.3,
     );
-    Tuple2<double, double> baseSpacing = const Tuple2(6.0, 0);
+    const baseSpacing = Tuple2<double, double>(6, 0);
     String fontFamily;
     switch (themeData.platform) {
       case TargetPlatform.iOS:
@@ -110,36 +115,36 @@ class DefaultStyles {
     return DefaultStyles(
         h1: DefaultTextBlockStyle(
             defaultTextStyle.style.copyWith(
-              fontSize: 34.0,
+              fontSize: 34,
               color: defaultTextStyle.style.color!.withOpacity(0.70),
               height: 1.15,
               fontWeight: FontWeight.w300,
             ),
-            const Tuple2(16.0, 0.0),
+            const Tuple2(16, 0),
-            const Tuple2(0.0, 0.0),
+            const Tuple2(0, 0),
             null),
         h2: DefaultTextBlockStyle(
             defaultTextStyle.style.copyWith(
-              fontSize: 24.0,
+              fontSize: 24,
               color: defaultTextStyle.style.color!.withOpacity(0.70),
               height: 1.15,
               fontWeight: FontWeight.normal,
             ),
-            const Tuple2(8.0, 0.0),
+            const Tuple2(8, 0),
-            const Tuple2(0.0, 0.0),
+            const Tuple2(0, 0),
             null),
         h3: DefaultTextBlockStyle(
             defaultTextStyle.style.copyWith(
-              fontSize: 20.0,
+              fontSize: 20,
               color: defaultTextStyle.style.color!.withOpacity(0.70),
               height: 1.25,
               fontWeight: FontWeight.w500,
             ),
-            const Tuple2(8.0, 0.0),
+            const Tuple2(8, 0),
-            const Tuple2(0.0, 0.0),
+            const Tuple2(0, 0),
             null),
         paragraph: DefaultTextBlockStyle(
-            baseStyle, const Tuple2(0.0, 0.0), const Tuple2(0.0, 0.0), null),
+            baseStyle, const Tuple2(0, 0), const Tuple2(0, 0), null),
         bold: const TextStyle(fontWeight: FontWeight.bold),
         italic: const TextStyle(fontStyle: FontStyle.italic),
         underline: const TextStyle(decoration: TextDecoration.underline),
@@ -150,19 +155,19 @@ class DefaultStyles {
         ),
         placeHolder: DefaultTextBlockStyle(
             defaultTextStyle.style.copyWith(
-              fontSize: 20.0,
+              fontSize: 20,
               height: 1.5,
               color: Colors.grey.withOpacity(0.6),
             ),
-            const Tuple2(0.0, 0.0),
+            const Tuple2(0, 0),
-            const Tuple2(0.0, 0.0),
+            const Tuple2(0, 0),
             null),
         lists: DefaultTextBlockStyle(
-            baseStyle, baseSpacing, const Tuple2(0.0, 6.0), null),
+            baseStyle, baseSpacing, const Tuple2(0, 6), null),
         quote: DefaultTextBlockStyle(
             TextStyle(color: baseStyle.color!.withOpacity(0.6)),
             baseSpacing,
-            const Tuple2(6.0, 2.0),
+            const Tuple2(6, 2),
             BoxDecoration(
               border: Border(
                 left: BorderSide(width: 4, color: Colors.grey.shade300),
@@ -172,24 +177,24 @@ class DefaultStyles {
             TextStyle(
               color: Colors.blue.shade900.withOpacity(0.9),
               fontFamily: fontFamily,
-              fontSize: 13.0,
+              fontSize: 13,
               height: 1.15,
             ),
             baseSpacing,
-            const Tuple2(0.0, 0.0),
+            const Tuple2(0, 0),
             BoxDecoration(
               color: Colors.grey.shade50,
               borderRadius: BorderRadius.circular(2),
             )),
         indent: DefaultTextBlockStyle(
-            baseStyle, baseSpacing, const Tuple2(0.0, 6.0), null),
+            baseStyle, baseSpacing, const Tuple2(0, 6), null),
         align: DefaultTextBlockStyle(
-            baseStyle, const Tuple2(0.0, 0.0), const Tuple2(0.0, 0.0), null),
+            baseStyle, const Tuple2(0, 0), const Tuple2(0, 0), null),
         leading: DefaultTextBlockStyle(
-            baseStyle, const Tuple2(0.0, 0.0), const Tuple2(0.0, 0.0), null),
+            baseStyle, const Tuple2(0, 0), const Tuple2(0, 0), null),
-        sizeSmall: const TextStyle(fontSize: 10.0),
+        sizeSmall: const TextStyle(fontSize: 10),
-        sizeLarge: const TextStyle(fontSize: 18.0),
+        sizeLarge: const TextStyle(fontSize: 18),
-        sizeHuge: const TextStyle(fontSize: 22.0));
+        sizeHuge: const TextStyle(fontSize: 22));
   }
 
   DefaultStyles merge(DefaultStyles other) {

lib/widgets/delegate.dart

@@ -2,10 +2,10 @@ import 'package:flutter/cupertino.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
-import 'package:flutter_quill/models/documents/nodes/leaf.dart';
-import 'package:flutter_quill/widgets/text_selection.dart';
 
+import '../models/documents/nodes/leaf.dart';
 import 'editor.dart';
+import 'text_selection.dart';
 
 typedef EmbedBuilder = Widget Function(BuildContext context, Embed node);
 
@@ -18,11 +18,11 @@ abstract class EditorTextSelectionGestureDetectorBuilderDelegate {
 }
 
 class EditorTextSelectionGestureDetectorBuilder {
+  EditorTextSelectionGestureDetectorBuilder(this.delegate);
+
   final EditorTextSelectionGestureDetectorBuilderDelegate delegate;
   bool shouldShowSelectionToolbar = true;
 
-  EditorTextSelectionGestureDetectorBuilder(this.delegate);
-
   EditorState? getEditor() {
     return delegate.getEditableTextKey().currentState;
   }
@@ -34,7 +34,7 @@ class EditorTextSelectionGestureDetectorBuilder {
   void onTapDown(TapDownDetails details) {
     getRenderEditor()!.handleTapDown(details);
 
-    PointerDeviceKind? kind = details.kind;
+    final kind = details.kind;
     shouldShowSelectionToolbar = kind == null ||
         kind == PointerDeviceKind.touch ||
         kind == PointerDeviceKind.stylus;

lib/widgets/editor.dart

@@ -8,25 +8,23 @@ import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
-import 'package:flutter_quill/models/documents/attribute.dart';
-import 'package:flutter_quill/models/documents/document.dart';
-import 'package:flutter_quill/models/documents/nodes/container.dart'
-    as container_node;
-import 'package:flutter_quill/models/documents/nodes/embed.dart';
-import 'package:flutter_quill/models/documents/nodes/leaf.dart' as leaf;
-import 'package:flutter_quill/models/documents/nodes/line.dart';
-import 'package:flutter_quill/models/documents/nodes/node.dart';
-import 'package:flutter_quill/widgets/image.dart';
-import 'package:flutter_quill/widgets/raw_editor.dart';
-import 'package:flutter_quill/widgets/text_selection.dart';
 import 'package:string_validator/string_validator.dart';
 import 'package:url_launcher/url_launcher.dart';
 
+import '../models/documents/attribute.dart';
+import '../models/documents/document.dart';
+import '../models/documents/nodes/container.dart' as container_node;
+import '../models/documents/nodes/embed.dart';
+import '../models/documents/nodes/leaf.dart' as leaf;
+import '../models/documents/nodes/line.dart';
 import 'box.dart';
 import 'controller.dart';
 import 'cursor.dart';
 import 'default_styles.dart';
 import 'delegate.dart';
+import 'image.dart';
+import 'raw_editor.dart';
+import 'text_selection.dart';
 
 const linkPrefixes = [
   'mailto:', // email
@@ -101,7 +99,7 @@ Widget _defaultEmbedBuilder(BuildContext context, leaf.Embed node) {
   assert(!kIsWeb, 'Please provide EmbedBuilder for Web');
   switch (node.value.type) {
     case 'image':
-      String imageUrl = _standardizeImageUrl(node.value.data);
+      final imageUrl = _standardizeImageUrl(node.value.data);
       return imageUrl.startsWith('http')
           ? Image.network(imageUrl)
           : isBase64(imageUrl)
@@ -116,6 +114,43 @@ Widget _defaultEmbedBuilder(BuildContext context, leaf.Embed node) {
 }
 
 class QuillEditor extends StatefulWidget {
+  const QuillEditor({
+    required this.controller,
+    required this.focusNode,
+    required this.scrollController,
+    required this.scrollable,
+    required this.padding,
+    required this.autoFocus,
+    required this.readOnly,
+    required this.expands,
+    this.showCursor,
+    this.placeholder,
+    this.enableInteractiveSelection = true,
+    this.minHeight,
+    this.maxHeight,
+    this.customStyles,
+    this.textCapitalization = TextCapitalization.sentences,
+    this.keyboardAppearance = Brightness.light,
+    this.scrollPhysics,
+    this.onLaunchUrl,
+    this.embedBuilder = _defaultEmbedBuilder,
+  });
+
+  factory QuillEditor.basic({
+    required QuillController controller,
+    required bool readOnly,
+  }) {
+    return QuillEditor(
+        controller: controller,
+        scrollController: ScrollController(),
+        scrollable: true,
+        focusNode: FocusNode(),
+        autoFocus: true,
+        readOnly: readOnly,
+        expands: false,
+        padding: EdgeInsets.zero);
+  }
+
   final QuillController controller;
   final FocusNode focusNode;
   final ScrollController scrollController;
@@ -146,45 +181,6 @@ class QuillEditor extends StatefulWidget {
   final bool Function(LongPressEndDetails details, TextPosition textPosition)? onSingleLongTapEnd;
   final EmbedBuilder embedBuilder;
 
-  const QuillEditor(
-      {required this.controller,
-      required this.focusNode,
-      required this.scrollController,
-      required this.scrollable,
-      required this.padding,
-      required this.autoFocus,
-      required this.readOnly,
-      required this.expands,
-      this.showCursor,
-      this.placeholder,
-      this.enableInteractiveSelection = true,
-      this.minHeight,
-      this.maxHeight,
-      this.customStyles,
-      this.textCapitalization = TextCapitalization.sentences,
-      this.keyboardAppearance = Brightness.light,
-      this.scrollPhysics,
-      this.onLaunchUrl,
-      this.onTapDown,
-      this.onTapUp,
-      this.onSingleLongTapStart,
-      this.onSingleLongTapMoveUpdate,
-      this.onSingleLongTapEnd,
-      this.embedBuilder = _defaultEmbedBuilder});
-
-  factory QuillEditor.basic(
-      {required QuillController controller, required bool readOnly}) {
-    return QuillEditor(
-        controller: controller,
-        scrollController: ScrollController(),
-        scrollable: true,
-        focusNode: FocusNode(),
-        autoFocus: true,
-        readOnly: readOnly,
-        expands: false,
-        padding: EdgeInsets.zero);
-  }
-
   @override
   _QuillEditorState createState() => _QuillEditorState();
 }
@@ -204,8 +200,8 @@ class _QuillEditorState extends State<QuillEditor>
 
   @override
   Widget build(BuildContext context) {
-    ThemeData theme = Theme.of(context);
+    final theme = Theme.of(context);
-    TextSelectionThemeData selectionTheme = TextSelectionTheme.of(context);
+    final selectionTheme = TextSelectionTheme.of(context);
 
     TextSelectionControls textSelectionControls;
     bool paintCursorAboveText;
@@ -229,7 +225,7 @@ class _QuillEditorState extends State<QuillEditor>
         break;
       case TargetPlatform.iOS:
       case TargetPlatform.macOS:
-        CupertinoThemeData cupertinoTheme = CupertinoTheme.of(context);
+        final cupertinoTheme = CupertinoTheme.of(context);
         textSelectionControls = cupertinoTextSelectionControls;
         paintCursorAboveText = true;
         cursorOpacityAnimates = true;
@@ -237,7 +233,7 @@ class _QuillEditorState extends State<QuillEditor>
             selectionTheme.cursorColor ?? cupertinoTheme.primaryColor;
         selectionColor = selectionTheme.selectionColor ??
             cupertinoTheme.primaryColor.withOpacity(0.40);
-        cursorRadius ??= const Radius.circular(2.0);
+        cursorRadius ??= const Radius.circular(2);
         cursorOffset = Offset(
             iOSHorizontalOffset / MediaQuery.of(context).devicePixelRatio, 0);
         break;
@@ -269,7 +265,7 @@ class _QuillEditorState extends State<QuillEditor>
           CursorStyle(
             color: cursorColor,
             backgroundColor: Colors.grey,
-            width: 2.0,
+            width: 2,
             radius: cursorRadius,
             offset: cursorOffset,
             paintAboveText: paintCursorAboveText,
@@ -286,6 +282,11 @@ class _QuillEditorState extends State<QuillEditor>
           widget.keyboardAppearance,
           widget.enableInteractiveSelection,
           widget.scrollPhysics,
+          widget.onTapDown,
+          widget.onTapUp,
+          widget.onSingleLongTapStart,
+          widget.onSingleLongTapMoveUpdate,
+          widget.onSingleLongTapEnd,
           widget.embedBuilder),
     );
   }
@@ -312,10 +313,10 @@ class _QuillEditorState extends State<QuillEditor>
 
 class _QuillEditorSelectionGestureDetectorBuilder
     extends EditorTextSelectionGestureDetectorBuilder {
-  final _QuillEditorState _state;
-
   _QuillEditorSelectionGestureDetectorBuilder(this._state) : super(_state);
 
+  final _QuillEditorState _state;
+
   @override
   void onForcePressStart(ForcePressDetails details) {
     super.onForcePressStart(details);
@@ -369,16 +370,14 @@ class _QuillEditorSelectionGestureDetectorBuilder
     if (_state.widget.controller.document.isEmpty()) {
       return false;
     }
-    TextPosition pos =
+    final pos = getRenderEditor()!.getPositionForOffset(details.globalPosition);
-        getRenderEditor()!.getPositionForOffset(details.globalPosition);
+    final result =
-    container_node.ChildQuery result =
         getEditor()!.widget.controller.document.queryChild(pos.offset);
     if (result.node == null) {
       return false;
     }
-    Line line = result.node as Line;
+    final line = result.node as Line;
-    container_node.ChildQuery segmentResult =
+    final segmentResult = line.queryChild(result.offset, false);
-        line.queryChild(result.offset, false);
     if (segmentResult.node == null) {
       if (line.length == 1) {
         // tapping when no text yet on this line
@@ -389,7 +388,7 @@ class _QuillEditorSelectionGestureDetectorBuilder
       }
       return false;
     }
-    leaf.Leaf segment = segmentResult.node as leaf.Leaf;
+    final segment = segmentResult.node as leaf.Leaf;
     if (segment.style.containsKey(Attribute.link.key)) {
       var launchUrl = getEditor()!.widget.onLaunchUrl;
       launchUrl ??= _launchUrl;
@@ -405,9 +404,9 @@ class _QuillEditorSelectionGestureDetectorBuilder
       return false;
     }
     if (getEditor()!.widget.readOnly && segment.value is BlockEmbed) {
-      BlockEmbed blockEmbed = segment.value as BlockEmbed;
+      final blockEmbed = segment.value as BlockEmbed;
       if (blockEmbed.type == 'image') {
-        final String imageUrl = _standardizeImageUrl(blockEmbed.data);
+        final imageUrl = _standardizeImageUrl(blockEmbed.data);
         Navigator.push(
           getEditor()!.context,
           MaterialPageRoute(
@@ -438,7 +437,7 @@ class _QuillEditorSelectionGestureDetectorBuilder
       return false;
     }
     // segmentResult.offset == 0 means tap at the beginning of the TextLine
-    String? listVal = line.style.attributes[Attribute.list.key]!.value;
+    final String? listVal = line.style.attributes[Attribute.list.key]!.value;
     if (listVal == Attribute.unchecked.value) {
       getEditor()!
           .widget
@@ -455,7 +454,7 @@ class _QuillEditorSelectionGestureDetectorBuilder
     return true;
   }
 
-  void _launchUrl(String url) async {
+  Future<void> _launchUrl(String url) async {
     await launch(url);
   }
 
@@ -485,7 +484,7 @@ class _QuillEditorSelectionGestureDetectorBuilder
 
     getEditor()!.hideToolbar();
 
-    bool positionSelected = _onTapping(details);
+    final positionSelected = _onTapping(details);
 
     if (delegate.getSelectionEnabled() && !positionSelected) {
       switch (Theme.of(_state.context).platform) {
@@ -567,6 +566,24 @@ typedef TextSelectionChangedHandler = void Function(
 
 class RenderEditor extends RenderEditableContainerBox
     implements RenderAbstractEditor {
+  RenderEditor(
+    List<RenderEditableBox>? children,
+    TextDirection textDirection,
+    EdgeInsetsGeometry padding,
+    this.document,
+    this.selection,
+    this._hasFocus,
+    this.onSelectionChanged,
+    this._startHandleLayerLink,
+    this._endHandleLayerLink,
+    EdgeInsets floatingCursorAddedMargin,
+  ) : super(
+          children,
+          document.root,
+          textDirection,
+          padding,
+        );
+
   Document document;
   TextSelection selection;
   bool _hasFocus = false;
@@ -582,24 +599,6 @@ class RenderEditor extends RenderEditableContainerBox
   ValueListenable<bool> get selectionEndInViewport => _selectionEndInViewport;
   final ValueNotifier<bool> _selectionEndInViewport = ValueNotifier<bool>(true);
 
-  RenderEditor(
-      List<RenderEditableBox>? children,
-      TextDirection textDirection,
-      EdgeInsetsGeometry padding,
-      this.document,
-      this.selection,
-      this._hasFocus,
-      this.onSelectionChanged,
-      this._startHandleLayerLink,
-      this._endHandleLayerLink,
-      EdgeInsets floatingCursorAddedMargin)
-      : super(
-          children,
-          document.root,
-          textDirection,
-          padding,
-        );
-
   void setDocument(Document doc) {
     if (document == doc) {
       return;
@@ -644,22 +643,21 @@ class RenderEditor extends RenderEditableContainerBox
   List<TextSelectionPoint> getEndpointsForSelection(
       TextSelection textSelection) {
     if (textSelection.isCollapsed) {
-      RenderEditableBox child = childAtPosition(textSelection.extent);
+      final child = childAtPosition(textSelection.extent);
-      TextPosition localPosition = TextPosition(
+      final localPosition = TextPosition(
-          offset:
+          offset: textSelection.extentOffset - child.getContainer().offset);
-              textSelection.extentOffset - child.getContainer().getOffset());
+      final localOffset = child.getOffsetForCaret(localPosition);
-      Offset localOffset = child.getOffsetForCaret(localPosition);
+      final parentData = child.parentData as BoxParentData;
-      BoxParentData parentData = child.parentData as BoxParentData;
       return <TextSelectionPoint>[
         TextSelectionPoint(
-            Offset(0.0, child.preferredLineHeight(localPosition)) +
+            Offset(0, child.preferredLineHeight(localPosition)) +
                 localOffset +
                 parentData.offset,
             null)
       ];
     }
 
-    Node? baseNode = _container.queryChild(textSelection.start, false).node;
+    final baseNode = _container.queryChild(textSelection.start, false).node;
 
     var baseChild = firstChild;
     while (baseChild != null) {
@@ -670,15 +668,14 @@ class RenderEditor extends RenderEditableContainerBox
     }
     assert(baseChild != null);
 
-    BoxParentData baseParentData = baseChild!.parentData as BoxParentData;
+    final baseParentData = baseChild!.parentData as BoxParentData;
-    TextSelection baseSelection =
+    final baseSelection =
         localSelection(baseChild.getContainer(), textSelection, true);
-    TextSelectionPoint basePoint =
+    var basePoint = baseChild.getBaseEndpointForSelection(baseSelection);
-        baseChild.getBaseEndpointForSelection(baseSelection);
     basePoint = TextSelectionPoint(
         basePoint.point + baseParentData.offset, basePoint.direction);
 
-    Node? extentNode = _container.queryChild(textSelection.end, false).node;
+    final extentNode = _container.queryChild(textSelection.end, false).node;
     RenderEditableBox? extentChild = baseChild;
     while (extentChild != null) {
       if (extentChild.getContainer() == extentNode) {
@@ -688,10 +685,10 @@ class RenderEditor extends RenderEditableContainerBox
     }
     assert(extentChild != null);
 
-    BoxParentData extentParentData = extentChild!.parentData as BoxParentData;
+    final extentParentData = extentChild!.parentData as BoxParentData;
-    TextSelection extentSelection =
+    final extentSelection =
         localSelection(extentChild.getContainer(), textSelection, true);
-    TextSelectionPoint extentPoint =
+    var extentPoint =
         extentChild.getExtentEndpointForSelection(extentSelection);
     extentPoint = TextSelectionPoint(
         extentPoint.point + extentParentData.offset, extentPoint.direction);
@@ -712,9 +709,9 @@ class RenderEditor extends RenderEditableContainerBox
     Offset? to,
     SelectionChangedCause cause,
   ) {
-    TextPosition firstPosition = getPositionForOffset(from);
+    final firstPosition = getPositionForOffset(from);
-    TextSelection firstWord = selectWordAtPosition(firstPosition);
+    final firstWord = selectWordAtPosition(firstPosition);
-    TextSelection lastWord =
+    final lastWord =
         to == null ? firstWord : selectWordAtPosition(getPositionForOffset(to));
 
     _handleSelectionChange(
@@ -731,7 +728,7 @@ class RenderEditor extends RenderEditableContainerBox
     TextSelection nextSelection,
     SelectionChangedCause cause,
   ) {
-    bool focusingEmpty = nextSelection.baseOffset == 0 &&
+    final focusingEmpty = nextSelection.baseOffset == 0 &&
         nextSelection.extentOffset == 0 &&
         !_hasFocus;
     if (nextSelection == selection &&
@@ -745,15 +742,15 @@ class RenderEditor extends RenderEditableContainerBox
   @override
   void selectWordEdge(SelectionChangedCause cause) {
     assert(_lastTapDownPosition != null);
-    TextPosition position = getPositionForOffset(_lastTapDownPosition!);
+    final position = getPositionForOffset(_lastTapDownPosition!);
-    RenderEditableBox child = childAtPosition(position);
+    final child = childAtPosition(position);
-    int nodeOffset = child.getContainer().getOffset();
+    final nodeOffset = child.getContainer().offset;
-    TextPosition localPosition = TextPosition(
+    final localPosition = TextPosition(
       offset: position.offset - nodeOffset,
       affinity: position.affinity,
     );
-    TextRange localWord = child.getWordBoundary(localPosition);
+    final localWord = child.getWordBoundary(localPosition);
-    TextRange word = TextRange(
+    final word = TextRange(
       start: localWord.start + nodeOffset,
       end: localWord.end + nodeOffset,
     );
@@ -777,17 +774,17 @@ class RenderEditor extends RenderEditableContainerBox
     Offset? to,
     SelectionChangedCause cause,
   ) {
-    TextPosition fromPosition = getPositionForOffset(from);
+    final fromPosition = getPositionForOffset(from);
-    TextPosition? toPosition = to == null ? null : getPositionForOffset(to);
+    final toPosition = to == null ? null : getPositionForOffset(to);
 
-    int baseOffset = fromPosition.offset;
+    var baseOffset = fromPosition.offset;
-    int extentOffset = fromPosition.offset;
+    var extentOffset = fromPosition.offset;
     if (toPosition != null) {
       baseOffset = math.min(fromPosition.offset, toPosition.offset);
       extentOffset = math.max(fromPosition.offset, toPosition.offset);
     }
 
-    TextSelection newSelection = TextSelection(
+    final newSelection = TextSelection(
       baseOffset: baseOffset,
       extentOffset: extentOffset,
       affinity: fromPosition.affinity,
@@ -807,12 +804,12 @@ class RenderEditor extends RenderEditableContainerBox
 
   @override
   TextSelection selectWordAtPosition(TextPosition position) {
-    RenderEditableBox child = childAtPosition(position);
+    final child = childAtPosition(position);
-    int nodeOffset = child.getContainer().getOffset();
+    final nodeOffset = child.getContainer().offset;
-    TextPosition localPosition = TextPosition(
+    final localPosition = TextPosition(
         offset: position.offset - nodeOffset, affinity: position.affinity);
-    TextRange localWord = child.getWordBoundary(localPosition);
+    final localWord = child.getWordBoundary(localPosition);
-    TextRange word = TextRange(
+    final word = TextRange(
       start: localWord.start + nodeOffset,
       end: localWord.end + nodeOffset,
     );
@@ -824,12 +821,12 @@ class RenderEditor extends RenderEditableContainerBox
 
   @override
   TextSelection selectLineAtPosition(TextPosition position) {
-    RenderEditableBox child = childAtPosition(position);
+    final child = childAtPosition(position);
-    int nodeOffset = child.getContainer().getOffset();
+    final nodeOffset = child.getContainer().offset;
-    TextPosition localPosition = TextPosition(
+    final localPosition = TextPosition(
         offset: position.offset - nodeOffset, affinity: position.affinity);
-    TextRange localLineRange = child.getLineBoundary(localPosition);
+    final localLineRange = child.getLineBoundary(localPosition);
-    TextRange line = TextRange(
+    final line = TextRange(
       start: localLineRange.start + nodeOffset,
       end: localLineRange.end + nodeOffset,
     );
@@ -879,21 +876,21 @@ class RenderEditor extends RenderEditableContainerBox
 
   @override
   double preferredLineHeight(TextPosition position) {
-    RenderEditableBox child = childAtPosition(position);
+    final child = childAtPosition(position);
-    return child.preferredLineHeight(TextPosition(
+    return child.preferredLineHeight(
-        offset: position.offset - child.getContainer().getOffset()));
+        TextPosition(offset: position.offset - child.getContainer().offset));
   }
 
   @override
   TextPosition getPositionForOffset(Offset offset) {
-    Offset local = globalToLocal(offset);
+    final local = globalToLocal(offset);
-    RenderEditableBox child = childAtOffset(local)!;
+    final child = childAtOffset(local)!;
 
-    BoxParentData parentData = child.parentData as BoxParentData;
+    final parentData = child.parentData as BoxParentData;
-    Offset localOffset = local - parentData.offset;
+    final localOffset = local - parentData.offset;
-    TextPosition localPosition = child.getPositionForOffset(localOffset);
+    final localPosition = child.getPositionForOffset(localOffset);
     return TextPosition(
-      offset: localPosition.offset + child.getContainer().getOffset(),
+      offset: localPosition.offset + child.getContainer().offset,
       affinity: localPosition.affinity,
     );
   }
@@ -905,15 +902,14 @@ class RenderEditor extends RenderEditableContainerBox
   /// Returns null if [selection] is already visible.
   double? getOffsetToRevealCursor(
       double viewportHeight, double scrollOffset, double offsetInViewport) {
-    List<TextSelectionPoint> endpoints = getEndpointsForSelection(selection);
+    final endpoints = getEndpointsForSelection(selection);
-    TextSelectionPoint endpoint = endpoints.first;
+    final endpoint = endpoints.first;
-    RenderEditableBox child = childAtPosition(selection.extent);
+    final child = childAtPosition(selection.extent);
     const kMargin = 8.0;
 
-    double caretTop = endpoint.point.dy -
+    final caretTop = endpoint.point.dy -
         child.preferredLineHeight(TextPosition(
-            offset:
+            offset: selection.extentOffset - child.getContainer().offset)) -
-                selection.extentOffset - child.getContainer().getOffset())) -
         kMargin +
         offsetInViewport;
     final caretBottom = endpoint.point.dy + kMargin + offsetInViewport;
@@ -926,7 +922,7 @@ class RenderEditor extends RenderEditableContainerBox
     if (dy == null) {
       return null;
     }
-    return math.max(dy, 0.0);
+    return math.max(dy, 0);
   }
 }
 
@@ -939,17 +935,20 @@ class RenderEditableContainerBox extends RenderBox
             EditableContainerParentData>,
         RenderBoxContainerDefaultsMixin<RenderEditableBox,
             EditableContainerParentData> {
+  RenderEditableContainerBox(
+    List<RenderEditableBox>? children,
+    this._container,
+    this.textDirection,
+    this._padding,
+  ) : assert(_padding.isNonNegative) {
+    addAll(children);
+  }
+
   container_node.Container _container;
   TextDirection textDirection;
   EdgeInsetsGeometry _padding;
   EdgeInsets? _resolvedPadding;
 
-  RenderEditableContainerBox(List<RenderEditableBox>? children, this._container,
-      this.textDirection, this._padding)
-      : assert(_padding.isNonNegative) {
-    addAll(children);
-  }
-
   container_node.Container getContainer() {
     return _container;
   }
@@ -988,7 +987,7 @@ class RenderEditableContainerBox extends RenderBox
   RenderEditableBox childAtPosition(TextPosition position) {
     assert(firstChild != null);
 
-    Node? targetNode = _container.queryChild(position.offset, false).node;
+    final targetNode = _container.queryChild(position.offset, false).node;
 
     var targetChild = firstChild;
     while (targetChild != null) {
@@ -1020,7 +1019,8 @@ class RenderEditableContainerBox extends RenderBox
     }
 
     var child = firstChild;
-    double dx = -offset.dx, dy = _resolvedPadding!.top;
+    final dx = -offset.dx;
+    var dy = _resolvedPadding!.top;
     while (child != null) {
       if (child.size.contains(offset.translate(dx, -dy))) {
         return child;
@@ -1047,16 +1047,15 @@ class RenderEditableContainerBox extends RenderBox
     _resolvePadding();
     assert(_resolvedPadding != null);
 
-    double mainAxisExtent = _resolvedPadding!.top;
+    var mainAxisExtent = _resolvedPadding!.top;
     var child = firstChild;
-    BoxConstraints innerConstraints =
+    final innerConstraints =
         BoxConstraints.tightFor(width: constraints.maxWidth)
             .deflate(_resolvedPadding!);
     while (child != null) {
       child.layout(innerConstraints, parentUsesSize: true);
-      final EditableContainerParentData childParentData =
+      final childParentData = (child.parentData as EditableContainerParentData)
-          child.parentData as EditableContainerParentData;
+        ..offset = Offset(_resolvedPadding!.left, mainAxisExtent);
-      childParentData.offset = Offset(_resolvedPadding!.left, mainAxisExtent);
       mainAxisExtent += child.size.height;
       assert(child.parentData == childParentData);
       child = childParentData.nextSibling;
@@ -1068,24 +1067,22 @@ class RenderEditableContainerBox extends RenderBox
   }
 
   double _getIntrinsicCrossAxis(double Function(RenderBox child) childSize) {
-    double extent = 0.0;
+    var extent = 0.0;
     var child = firstChild;
     while (child != null) {
       extent = math.max(extent, childSize(child));
-      EditableContainerParentData childParentData =
+      final childParentData = child.parentData as EditableContainerParentData;
-          child.parentData as EditableContainerParentData;
       child = childParentData.nextSibling;
     }
     return extent;
   }
 
   double _getIntrinsicMainAxis(double Function(RenderBox child) childSize) {
-    double extent = 0.0;
+    var extent = 0.0;
     var child = firstChild;
     while (child != null) {
       extent += childSize(child);
-      EditableContainerParentData childParentData =
+      final childParentData = child.parentData as EditableContainerParentData;
-          child.parentData as EditableContainerParentData;
       child = childParentData.nextSibling;
     }
     return extent;
@@ -1094,9 +1091,9 @@ class RenderEditableContainerBox extends RenderBox
   @override
   double computeMinIntrinsicWidth(double height) {
     _resolvePadding();
-    return _getIntrinsicCrossAxis((RenderBox child) {
+    return _getIntrinsicCrossAxis((child) {
-      double childHeight = math.max(
+      final childHeight = math.max<double>(
-          0.0, height - _resolvedPadding!.top + _resolvedPadding!.bottom);
+          0, height - _resolvedPadding!.top + _resolvedPadding!.bottom);
       return child.getMinIntrinsicWidth(childHeight) +
           _resolvedPadding!.left +
           _resolvedPadding!.right;
@@ -1106,9 +1103,9 @@ class RenderEditableContainerBox extends RenderBox
   @override
   double computeMaxIntrinsicWidth(double height) {
     _resolvePadding();
-    return _getIntrinsicCrossAxis((RenderBox child) {
+    return _getIntrinsicCrossAxis((child) {
-      double childHeight = math.max(
+      final childHeight = math.max<double>(
-          0.0, height - _resolvedPadding!.top + _resolvedPadding!.bottom);
+          0, height - _resolvedPadding!.top + _resolvedPadding!.bottom);
       return child.getMaxIntrinsicWidth(childHeight) +
           _resolvedPadding!.left +
           _resolvedPadding!.right;
@@ -1118,9 +1115,9 @@ class RenderEditableContainerBox extends RenderBox
   @override
   double computeMinIntrinsicHeight(double width) {
     _resolvePadding();
-    return _getIntrinsicMainAxis((RenderBox child) {
+    return _getIntrinsicMainAxis((child) {
-      double childWidth = math.max(
+      final childWidth = math.max<double>(
-          0.0, width - _resolvedPadding!.left + _resolvedPadding!.right);
+          0, width - _resolvedPadding!.left + _resolvedPadding!.right);
       return child.getMinIntrinsicHeight(childWidth) +
           _resolvedPadding!.top +
           _resolvedPadding!.bottom;
@@ -1130,9 +1127,9 @@ class RenderEditableContainerBox extends RenderBox
   @override
   double computeMaxIntrinsicHeight(double width) {
     _resolvePadding();
-    return _getIntrinsicMainAxis((RenderBox child) {
+    return _getIntrinsicMainAxis((child) {
-      final childWidth = math.max(
+      final childWidth = math.max<double>(
-          0.0, width - _resolvedPadding!.left + _resolvedPadding!.right);
+          0, width - _resolvedPadding!.left + _resolvedPadding!.right);
       return child.getMaxIntrinsicHeight(childWidth) +
           _resolvedPadding!.top +
           _resolvedPadding!.bottom;

lib/widgets/keyboard_listener.dart

@@ -9,9 +9,12 @@ typedef InputShortcutCallback = void Function(InputShortcut? shortcut);
 typedef OnDeleteCallback = void Function(bool forward);
 
 class KeyboardListener {
+  KeyboardListener(this.onCursorMove, this.onShortcut, this.onDelete);
+
   final CursorMoveCallback onCursorMove;
   final InputShortcutCallback onShortcut;
   final OnDeleteCallback onDelete;
+
   static final Set<LogicalKeyboardKey> _moveKeys = <LogicalKeyboardKey>{
     LogicalKeyboardKey.arrowRight,
     LogicalKeyboardKey.arrowLeft,
@@ -59,8 +62,6 @@ class KeyboardListener {
     LogicalKeyboardKey.keyA: InputShortcut.SELECT_ALL,
   };
 
-  KeyboardListener(this.onCursorMove, this.onShortcut, this.onDelete);
-
   bool handleRawKeyEvent(RawKeyEvent event) {
     if (kIsWeb) {
       // On web platform, we should ignore the key because it's processed already.
@@ -71,10 +72,10 @@ class KeyboardListener {
       return false;
     }
 
-    Set<LogicalKeyboardKey> keysPressed =
+    final keysPressed =
         LogicalKeyboardKey.collapseSynonyms(RawKeyboard.instance.keysPressed);
-    LogicalKeyboardKey key = event.logicalKey;
+    final key = event.logicalKey;
-    bool isMacOS = event.data is RawKeyEventDataMacOs;
+    final isMacOS = event.data is RawKeyEventDataMacOs;
     if (!_nonModifierKeys.contains(key) ||
         keysPressed
                 .difference(isMacOS ? _macOsModifierKeys : _modifierKeys)

lib/widgets/proxy.dart

@@ -4,12 +4,12 @@ import 'package:flutter/widgets.dart';
 import 'box.dart';
 
 class BaselineProxy extends SingleChildRenderObjectWidget {
-  final TextStyle? textStyle;
-  final EdgeInsets? padding;
-
   const BaselineProxy({Key? key, Widget? child, this.textStyle, this.padding})
       : super(key: key, child: child);
 
+  final TextStyle? textStyle;
+  final EdgeInsets? padding;
+
   @override
   RenderBaselineProxy createRenderObject(BuildContext context) {
     return RenderBaselineProxy(
@@ -87,14 +87,14 @@ class RenderEmbedProxy extends RenderProxyBox implements RenderContentProxyBox {
   List<TextBox> getBoxesForSelection(TextSelection selection) {
     if (!selection.isCollapsed) {
       return <TextBox>[
-        TextBox.fromLTRBD(0.0, 0.0, size.width, size.height, TextDirection.ltr)
+        TextBox.fromLTRBD(0, 0, size.width, size.height, TextDirection.ltr)
       ];
     }
 
-    double left = selection.extentOffset == 0 ? 0.0 : size.width;
+    final left = selection.extentOffset == 0 ? 0.0 : size.width;
-    double right = selection.extentOffset == 0 ? 0.0 : size.width;
+    final right = selection.extentOffset == 0 ? 0.0 : size.width;
     return <TextBox>[
-      TextBox.fromLTRBD(left, 0.0, right, size.height, TextDirection.ltr)
+      TextBox.fromLTRBD(left, 0, right, size.height, TextDirection.ltr)
     ];
   }
 
@@ -104,7 +104,7 @@ class RenderEmbedProxy extends RenderProxyBox implements RenderContentProxyBox {
   @override
   Offset getOffsetForCaret(TextPosition position, Rect? caretPrototype) {
     assert(position.offset <= 1 && position.offset >= 0);
-    return position.offset == 0 ? Offset.zero : Offset(size.width, 0.0);
+    return position.offset == 0 ? Offset.zero : Offset(size.width, 0);
   }
 
   @override
@@ -122,6 +122,18 @@ class RenderEmbedProxy extends RenderProxyBox implements RenderContentProxyBox {
 }
 
 class RichTextProxy extends SingleChildRenderObjectWidget {
+  const RichTextProxy(
+    RichText child,
+    this.textStyle,
+    this.textAlign,
+    this.textDirection,
+    this.textScaleFactor,
+    this.locale,
+    this.strutStyle,
+    this.textWidthBasis,
+    this.textHeightBehavior,
+  ) : super(child: child);
+
   final TextStyle textStyle;
   final TextAlign textAlign;
   final TextDirection textDirection;
@@ -145,29 +157,18 @@ class RichTextProxy extends SingleChildRenderObjectWidget {
         textHeightBehavior);
   }
 
-  const RichTextProxy(
-      RichText child,
-      this.textStyle,
-      this.textAlign,
-      this.textDirection,
-      this.textScaleFactor,
-      this.locale,
-      this.strutStyle,
-      this.textWidthBasis,
-      this.textHeightBehavior)
-      : super(child: child);
-
   @override
   void updateRenderObject(
       BuildContext context, covariant RenderParagraphProxy renderObject) {
-    renderObject.textStyle = textStyle;
+    renderObject
-    renderObject.textAlign = textAlign;
+      ..textStyle = textStyle
-    renderObject.textDirection = textDirection;
+      ..textAlign = textAlign
-    renderObject.textScaleFactor = textScaleFactor;
+      ..textDirection = textDirection
-    renderObject.locale = locale;
+      ..textScaleFactor = textScaleFactor
-    renderObject.strutStyle = strutStyle;
+      ..locale = locale
-    renderObject.textWidthBasis = textWidthBasis;
+      ..strutStyle = strutStyle
-    renderObject.textHeightBehavior = textHeightBehavior;
+      ..textWidthBasis = textWidthBasis
+      ..textHeightBehavior = textHeightBehavior;
   }
 }
 

lib/widgets/raw_editor.dart

@@ -9,27 +9,58 @@ import 'package:flutter/rendering.dart';
 import 'package:flutter/scheduler.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_keyboard_visibility/flutter_keyboard_visibility.dart';
-import 'package:flutter_quill/models/documents/attribute.dart';
-import 'package:flutter_quill/models/documents/document.dart';
-import 'package:flutter_quill/models/documents/nodes/block.dart';
-import 'package:flutter_quill/models/documents/nodes/line.dart';
-import 'package:flutter_quill/models/documents/nodes/node.dart';
-import 'package:flutter_quill/utils/diff_delta.dart';
-import 'package:flutter_quill/widgets/default_styles.dart';
-import 'package:flutter_quill/widgets/proxy.dart';
-import 'package:flutter_quill/widgets/text_block.dart';
-import 'package:flutter_quill/widgets/text_line.dart';
-import 'package:flutter_quill/widgets/text_selection.dart';
 import 'package:tuple/tuple.dart';
 
-import 'box.dart';
+import '../models/documents/attribute.dart';
+import '../models/documents/document.dart';
+import '../models/documents/nodes/block.dart';
+import '../models/documents/nodes/line.dart';
+import '../utils/diff_delta.dart';
 import 'controller.dart';
 import 'cursor.dart';
+import 'default_styles.dart';
 import 'delegate.dart';
 import 'editor.dart';
 import 'keyboard_listener.dart';
+import 'proxy.dart';
+import 'text_block.dart';
+import 'text_line.dart';
+import 'text_selection.dart';
 
 class RawEditor extends StatefulWidget {
+  const RawEditor(
+    Key key,
+    this.controller,
+    this.focusNode,
+    this.scrollController,
+    this.scrollable,
+    this.padding,
+    this.readOnly,
+    this.placeholder,
+    this.onLaunchUrl,
+    this.toolbarOptions,
+    this.showSelectionHandles,
+    bool? showCursor,
+    this.cursorStyle,
+    this.textCapitalization,
+    this.maxHeight,
+    this.minHeight,
+    this.customStyles,
+    this.expands,
+    this.autoFocus,
+    this.selectionColor,
+    this.selectionCtrls,
+    this.keyboardAppearance,
+    this.enableInteractiveSelection,
+    this.scrollPhysics,
+    this.embedBuilder,
+  )   : assert(maxHeight == null || maxHeight > 0, 'maxHeight cannot be null'),
+        assert(minHeight == null || minHeight >= 0, 'minHeight cannot be null'),
+        assert(maxHeight == null || minHeight == null || maxHeight >= minHeight,
+            'maxHeight cannot be null'),
+        showCursor = showCursor ?? true,
+        super(key: key);
+
   final QuillController controller;
   final FocusNode focusNode;
   final ScrollController scrollController;
@@ -55,39 +86,6 @@ class RawEditor extends StatefulWidget {
   final ScrollPhysics? scrollPhysics;
   final EmbedBuilder embedBuilder;
 
-  const RawEditor(
-      Key key,
-      this.controller,
-      this.focusNode,
-      this.scrollController,
-      this.scrollable,
-      this.padding,
-      this.readOnly,
-      this.placeholder,
-      this.onLaunchUrl,
-      this.toolbarOptions,
-      this.showSelectionHandles,
-      bool? showCursor,
-      this.cursorStyle,
-      this.textCapitalization,
-      this.maxHeight,
-      this.minHeight,
-      this.customStyles,
-      this.expands,
-      this.autoFocus,
-      this.selectionColor,
-      this.selectionCtrls,
-      this.keyboardAppearance,
-      this.enableInteractiveSelection,
-      this.scrollPhysics,
-      this.embedBuilder)
-      : assert(maxHeight == null || maxHeight > 0, 'maxHeight cannot be null'),
-        assert(minHeight == null || minHeight >= 0, 'minHeight cannot be null'),
-        assert(maxHeight == null || minHeight == null || maxHeight >= minHeight,
-            'maxHeight cannot be null'),
-        showCursor = showCursor ?? true,
-        super(key: key);
-
   @override
   State<StatefulWidget> createState() {
     return RawEditorState();
@@ -140,7 +138,7 @@ class RawEditorState extends EditorState
   bool get _hasFocus => widget.focusNode.hasFocus;
 
   TextDirection get _textDirection {
-    TextDirection result = Directionality.of(context);
+    final result = Directionality.of(context);
     return result;
   }
 
@@ -153,13 +151,13 @@ class RawEditorState extends EditorState
     if (wordModifier && lineModifier) {
       return;
     }
-    TextSelection selection = widget.controller.selection;
+    final selection = widget.controller.selection;
 
-    TextSelection newSelection = widget.controller.selection;
+    var newSelection = widget.controller.selection;
 
-    String plainText = textEditingValue.text;
+    final plainText = textEditingValue.text;
 
-    bool rightKey = key == LogicalKeyboardKey.arrowRight,
+    final rightKey = key == LogicalKeyboardKey.arrowRight,
         leftKey = key == LogicalKeyboardKey.arrowLeft,
         upKey = key == LogicalKeyboardKey.arrowUp,
         downKey = key == LogicalKeyboardKey.arrowDown;
@@ -184,7 +182,7 @@ class RawEditorState extends EditorState
 
   TextSelection _placeCollapsedSelection(TextSelection selection,
       TextSelection newSelection, bool leftKey, bool rightKey) {
-    int newOffset = newSelection.extentOffset;
+    var newOffset = newSelection.extentOffset;
     if (!selection.isCollapsed) {
       if (leftKey) {
         newOffset = newSelection.baseOffset < newSelection.extentOffset
@@ -206,41 +204,38 @@ class RawEditorState extends EditorState
       TextSelection selection,
       TextSelection newSelection,
       String plainText) {
-    TextPosition originPosition = TextPosition(
+    final originPosition = TextPosition(
         offset: upKey ? selection.baseOffset : selection.extentOffset);
 
-    RenderEditableBox child =
+    final child = getRenderEditor()!.childAtPosition(originPosition);
-        getRenderEditor()!.childAtPosition(originPosition);
+    final localPosition = TextPosition(
-    TextPosition localPosition = TextPosition(
+        offset: originPosition.offset - child.getContainer().documentOffset);
-        offset:
-            originPosition.offset - child.getContainer().getDocumentOffset());
 
-    TextPosition? position = upKey
+    var position = upKey
         ? child.getPositionAbove(localPosition)
         : child.getPositionBelow(localPosition);
 
     if (position == null) {
-      var sibling = upKey
+      final sibling = upKey
           ? getRenderEditor()!.childBefore(child)
           : getRenderEditor()!.childAfter(child);
       if (sibling == null) {
         position = TextPosition(offset: upKey ? 0 : plainText.length - 1);
       } else {
-        Offset finalOffset = Offset(
+        final finalOffset = Offset(
             child.getOffsetForCaret(localPosition).dx,
             sibling
                 .getOffsetForCaret(TextPosition(
                     offset: upKey ? sibling.getContainer().length - 1 : 0))
                 .dy);
-        TextPosition siblingPosition =
+        final siblingPosition = sibling.getPositionForOffset(finalOffset);
-            sibling.getPositionForOffset(finalOffset);
         position = TextPosition(
-            offset: sibling.getContainer().getDocumentOffset() +
+            offset:
-                siblingPosition.offset);
+                sibling.getContainer().documentOffset + siblingPosition.offset);
       }
     } else {
       position = TextPosition(
-          offset: child.getContainer().getDocumentOffset() + position.offset);
+          offset: child.getContainer().documentOffset + position.offset);
     }
 
     if (position.offset == newSelection.extentOffset) {
@@ -273,28 +268,28 @@ class RawEditorState extends EditorState
       bool shift) {
     if (wordModifier) {
       if (leftKey) {
-        TextSelection textSelection = getRenderEditor()!.selectWordAtPosition(
+        final textSelection = getRenderEditor()!.selectWordAtPosition(
             TextPosition(
                 offset: _previousCharacter(
                     newSelection.extentOffset, plainText, false)));
         return newSelection.copyWith(extentOffset: textSelection.baseOffset);
       }
-      TextSelection textSelection = getRenderEditor()!.selectWordAtPosition(
+      final textSelection = getRenderEditor()!.selectWordAtPosition(
           TextPosition(
               offset:
                   _nextCharacter(newSelection.extentOffset, plainText, false)));
       return newSelection.copyWith(extentOffset: textSelection.extentOffset);
     } else if (lineModifier) {
       if (leftKey) {
-        TextSelection textSelection = getRenderEditor()!.selectLineAtPosition(
+        final textSelection = getRenderEditor()!.selectLineAtPosition(
             TextPosition(
                 offset: _previousCharacter(
                     newSelection.extentOffset, plainText, false)));
         return newSelection.copyWith(extentOffset: textSelection.baseOffset);
       }
-      int startPoint = newSelection.extentOffset;
+      final startPoint = newSelection.extentOffset;
       if (startPoint < plainText.length) {
-        TextSelection textSelection = getRenderEditor()!
+        final textSelection = getRenderEditor()!
             .selectLineAtPosition(TextPosition(offset: startPoint));
         return newSelection.copyWith(extentOffset: textSelection.extentOffset);
       }
@@ -302,9 +297,9 @@ class RawEditorState extends EditorState
     }
 
     if (rightKey && newSelection.extentOffset < plainText.length) {
-      int nextExtent =
+      final nextExtent =
           _nextCharacter(newSelection.extentOffset, plainText, true);
-      int distance = nextExtent - newSelection.extentOffset;
+      final distance = nextExtent - newSelection.extentOffset;
       newSelection = newSelection.copyWith(extentOffset: nextExtent);
       if (shift) {
         _cursorResetLocation += distance;
@@ -313,9 +308,9 @@ class RawEditorState extends EditorState
     }
 
     if (leftKey && newSelection.extentOffset > 0) {
-      int previousExtent =
+      final previousExtent =
           _previousCharacter(newSelection.extentOffset, plainText, true);
-      int distance = newSelection.extentOffset - previousExtent;
+      final distance = newSelection.extentOffset - previousExtent;
       newSelection = newSelection.copyWith(extentOffset: previousExtent);
       if (shift) {
         _cursorResetLocation -= distance;
@@ -331,8 +326,8 @@ class RawEditorState extends EditorState
       return string.length;
     }
 
-    int count = 0;
+    var count = 0;
-    Characters remain = string.characters.skipWhile((String currentString) {
+    final remain = string.characters.skipWhile((currentString) {
       if (count <= index) {
         count += currentString.length;
         return true;
@@ -351,9 +346,9 @@ class RawEditorState extends EditorState
       return 0;
     }
 
-    int count = 0;
+    var count = 0;
     int? lastNonWhitespace;
-    for (String currentString in string.characters) {
+    for (final currentString in string.characters) {
       if (!includeWhitespace &&
           !WHITE_SPACE.contains(
               currentString.characters.first.toString().codeUnitAt(0))) {
@@ -411,7 +406,7 @@ class RawEditorState extends EditorState
       return;
     }
 
-    TextEditingValue actualValue = textEditingValue.copyWith(
+    final actualValue = textEditingValue.copyWith(
       composing: _lastKnownRemoteTextEditingValue!.composing,
     );
 
@@ -419,7 +414,7 @@ class RawEditorState extends EditorState
       return;
     }
 
-    bool shouldRemember =
+    final shouldRemember =
         textEditingValue.text != _lastKnownRemoteTextEditingValue!.text;
     _lastKnownRemoteTextEditingValue = actualValue;
     _textInputConnection!.setEditingState(actualValue);
@@ -456,13 +451,12 @@ class RawEditorState extends EditorState
       return;
     }
 
-    TextEditingValue effectiveLastKnownValue =
+    final effectiveLastKnownValue = _lastKnownRemoteTextEditingValue!;
-        _lastKnownRemoteTextEditingValue!;
     _lastKnownRemoteTextEditingValue = value;
-    String oldText = effectiveLastKnownValue.text;
+    final oldText = effectiveLastKnownValue.text;
-    String text = value.text;
+    final text = value.text;
-    int cursorPosition = value.selection.extentOffset;
+    final cursorPosition = value.selection.extentOffset;
-    Diff diff = getDiff(oldText, text, cursorPosition);
+    final diff = getDiff(oldText, text, cursorPosition);
     widget.controller.replaceText(
         diff.start, diff.deleted.length, diff.inserted, value.selection);
   }
@@ -513,7 +507,7 @@ class RawEditorState extends EditorState
     _focusAttachment!.reparent();
     super.build(context);
 
-    Document _doc = widget.controller.document;
+    var _doc = widget.controller.document;
     if (_doc.isEmpty() &&
         !widget.focusNode.hasFocus &&
         widget.placeholder != null) {
@@ -540,7 +534,7 @@ class RawEditorState extends EditorState
     );
 
     if (widget.scrollable) {
-      EdgeInsets baselinePadding =
+      final baselinePadding =
           EdgeInsets.only(top: _styles!.paragraph!.verticalSpacing.item1);
       child = BaselineProxy(
         textStyle: _styles!.paragraph!.style,
@@ -553,7 +547,7 @@ class RawEditorState extends EditorState
       );
     }
 
-    BoxConstraints constraints = widget.expands
+    final constraints = widget.expands
         ? const BoxConstraints.expand()
         : BoxConstraints(
             minHeight: widget.minHeight ?? 0.0,
@@ -584,15 +578,14 @@ class RawEditorState extends EditorState
 
   List<Widget> _buildChildren(Document doc, BuildContext context) {
     final result = <Widget>[];
-    Map<int, int> indentLevelCounts = {};
+    final indentLevelCounts = <int, int>{};
-    for (Node node in doc.root.children) {
+    for (final node in doc.root.children) {
       if (node is Line) {
-        EditableTextLine editableTextLine =
+        final editableTextLine = _getEditableTextLineFromNode(node, context);
-            _getEditableTextLineFromNode(node, context);
         result.add(editableTextLine);
       } else if (node is Block) {
-        Map<String, Attribute> attrs = node.style.attributes;
+        final attrs = node.style.attributes;
-        EditableTextBlock editableTextBlock = EditableTextBlock(
+        final editableTextBlock = EditableTextBlock(
             node,
             _textDirection,
             _getVerticalSpacingForBlock(node, _styles),
@@ -602,7 +595,7 @@ class RawEditorState extends EditorState
             widget.enableInteractiveSelection,
             _hasFocus,
             attrs.containsKey(Attribute.codeBlock.key)
-                ? const EdgeInsets.all(16.0)
+                ? const EdgeInsets.all(16)
                 : null,
             widget.embedBuilder,
             _cursorCont,
@@ -617,13 +610,13 @@ class RawEditorState extends EditorState
 
   EditableTextLine _getEditableTextLineFromNode(
       Line node, BuildContext context) {
-    TextLine textLine = TextLine(
+    final textLine = TextLine(
       line: node,
       textDirection: _textDirection,
       embedBuilder: widget.embedBuilder,
       styles: _styles!,
     );
-    EditableTextLine editableTextLine = EditableTextLine(
+    final editableTextLine = EditableTextLine(
         node,
         null,
         textLine,
@@ -641,9 +634,9 @@ class RawEditorState extends EditorState
 
   Tuple2<double, double> _getVerticalSpacingForLine(
       Line line, DefaultStyles? defaultStyles) {
-    Map<String, Attribute> attrs = line.style.attributes;
+    final attrs = line.style.attributes;
     if (attrs.containsKey(Attribute.header.key)) {
-      int? level = attrs[Attribute.header.key]!.value;
+      final int? level = attrs[Attribute.header.key]!.value;
       switch (level) {
         case 1:
           return defaultStyles!.h1!.verticalSpacing;
@@ -661,7 +654,7 @@ class RawEditorState extends EditorState
 
   Tuple2<double, double> _getVerticalSpacingForBlock(
       Block node, DefaultStyles? defaultStyles) {
-    Map<String, Attribute> attrs = node.style.attributes;
+    final attrs = node.style.attributes;
     if (attrs.containsKey(Attribute.blockQuote.key)) {
       return defaultStyles!.quote!.verticalSpacing;
     } else if (attrs.containsKey(Attribute.codeBlock.key)) {
@@ -704,7 +697,7 @@ class RawEditorState extends EditorState
       _keyboardVisibilityController = KeyboardVisibilityController();
       _keyboardVisible = _keyboardVisibilityController!.isVisible;
       _keyboardVisibilitySubscription =
-          _keyboardVisibilityController?.onChange.listen((bool visible) {
+          _keyboardVisibilityController?.onChange.listen((visible) {
         _keyboardVisible = visible;
         if (visible) {
           _onChangeTextEditingValue();
@@ -720,8 +713,8 @@ class RawEditorState extends EditorState
   @override
   void didChangeDependencies() {
     super.didChangeDependencies();
-    DefaultStyles? parentStyles = QuillStyles.getStyles(context, true);
+    final parentStyles = QuillStyles.getStyles(context, true);
-    DefaultStyles defaultStyles = DefaultStyles.getInstance(context);
+    final defaultStyles = DefaultStyles.getInstance(context);
     _styles = (parentStyles != null)
         ? defaultStyles.merge(parentStyles)
         : defaultStyles;
@@ -784,27 +777,26 @@ class RawEditorState extends EditorState
   }
 
   void handleDelete(bool forward) {
-    TextSelection selection = widget.controller.selection;
+    final selection = widget.controller.selection;
-    String plainText = textEditingValue.text;
+    final plainText = textEditingValue.text;
-    int cursorPosition = selection.start;
+    var cursorPosition = selection.start;
-    String textBefore = selection.textBefore(plainText);
+    var textBefore = selection.textBefore(plainText);
-    String textAfter = selection.textAfter(plainText);
+    var textAfter = selection.textAfter(plainText);
     if (selection.isCollapsed) {
       if (!forward && textBefore.isNotEmpty) {
-        final int characterBoundary =
+        final characterBoundary =
             _previousCharacter(textBefore.length, textBefore, true);
         textBefore = textBefore.substring(0, characterBoundary);
         cursorPosition = characterBoundary;
       }
       if (forward && textAfter.isNotEmpty && textAfter != '\n') {
-        final int deleteCount = _nextCharacter(0, textAfter, true);
+        final deleteCount = _nextCharacter(0, textAfter, true);
         textAfter = textAfter.substring(deleteCount);
       }
     }
-    TextSelection newSelection =
+    final newSelection = TextSelection.collapsed(offset: cursorPosition);
-        TextSelection.collapsed(offset: cursorPosition);
+    final newText = textBefore + textAfter;
-    String newText = textBefore + textAfter;
+    final size = plainText.length - newText.length;
-    int size = plainText.length - newText.length;
     widget.controller.replaceText(
       cursorPosition,
       size,
@@ -813,9 +805,9 @@ class RawEditorState extends EditorState
     );
   }
 
-  void handleShortcut(InputShortcut? shortcut) async {
+  Future<void> handleShortcut(InputShortcut? shortcut) async {
-    TextSelection selection = widget.controller.selection;
+    final selection = widget.controller.selection;
-    String plainText = textEditingValue.text;
+    final plainText = textEditingValue.text;
     if (shortcut == InputShortcut.COPY) {
       if (!selection.isCollapsed) {
         await Clipboard.setData(
@@ -844,7 +836,7 @@ class RawEditorState extends EditorState
       return;
     }
     if (shortcut == InputShortcut.PASTE && !widget.readOnly) {
-      ClipboardData? data = await Clipboard.getData(Clipboard.kTextPlain);
+      final data = await Clipboard.getData(Clipboard.kTextPlain);
       if (data != null) {
         widget.controller.replaceText(
           selection.start,
@@ -913,12 +905,13 @@ class RawEditorState extends EditorState
     _cursorCont.startOrStopCursorTimerIfNeeded(
         _hasFocus, widget.controller.selection);
     if (hasConnection) {
-      _cursorCont.stopCursorTimer(resetCharTicks: false);
+      _cursorCont
-      _cursorCont.startCursorTimer();
+        ..stopCursorTimer(resetCharTicks: false)
+        ..startCursorTimer();
     }
 
     SchedulerBinding.instance!.addPostFrameCallback(
-        (Duration _) => _updateOrDisposeSelectionOverlayIfNeeded());
+        (_) => _updateOrDisposeSelectionOverlayIfNeeded());
     if (mounted) {
       setState(() {
         // Use widget.controller.value in build()
@@ -989,12 +982,12 @@ class RawEditorState extends EditorState
     }
 
     _showCaretOnScreenScheduled = true;
-    SchedulerBinding.instance!.addPostFrameCallback((Duration _) {
+    SchedulerBinding.instance!.addPostFrameCallback((_) {
       _showCaretOnScreenScheduled = false;
 
       final viewport = RenderAbstractViewport.of(getRenderEditor())!;
       final editorOffset = getRenderEditor()!
-          .localToGlobal(const Offset(0.0, 0.0), ancestor: viewport);
+          .localToGlobal(const Offset(0, 0), ancestor: viewport);
       final offsetInViewport = _scrollController!.offset + editorOffset.dy;
 
       final offset = getRenderEditor()!.getOffsetToRevealCursor(
@@ -1065,7 +1058,7 @@ class RawEditorState extends EditorState
     }
   }
 
-  void __setEditingValue(TextEditingValue value) async {
+  Future<void> __setEditingValue(TextEditingValue value) async {
     if (await __isItCut(value)) {
       widget.controller.replaceText(
         textEditingValue.selection.start,
@@ -1074,8 +1067,8 @@ class RawEditorState extends EditorState
         value.selection,
       );
     } else {
-      final TextEditingValue value = textEditingValue;
+      final value = textEditingValue;
-      final ClipboardData? data = await Clipboard.getData(Clipboard.kTextPlain);
+      final data = await Clipboard.getData(Clipboard.kTextPlain);
       if (data != null) {
         final length =
             textEditingValue.selection.end - textEditingValue.selection.start;
@@ -1095,7 +1088,7 @@ class RawEditorState extends EditorState
   }
 
   Future<bool> __isItCut(TextEditingValue value) async {
-    ClipboardData? data = await Clipboard.getData(Clipboard.kTextPlain);
+    final data = await Clipboard.getData(Clipboard.kTextPlain);
     if (data == null) {
       return false;
     }
@@ -1175,14 +1168,15 @@ class _Editor extends MultiChildRenderObjectWidget {
   @override
   void updateRenderObject(
       BuildContext context, covariant RenderEditor renderObject) {
-    renderObject.document = document;
+    renderObject
-    renderObject.setContainer(document.root);
+      ..document = document
-    renderObject.textDirection = textDirection;
+      ..setContainer(document.root)
-    renderObject.setHasFocus(hasFocus);
+      ..textDirection = textDirection
-    renderObject.setSelection(selection);
+      ..setHasFocus(hasFocus)
-    renderObject.setStartHandleLayerLink(startHandleLayerLink);
+      ..setSelection(selection)
-    renderObject.setEndHandleLayerLink(endHandleLayerLink);
+      ..setStartHandleLayerLink(startHandleLayerLink)
-    renderObject.onSelectionChanged = onSelectionChanged;
+      ..setEndHandleLayerLink(endHandleLayerLink)
-    renderObject.setPadding(padding);
+      ..onSelectionChanged = onSelectionChanged
+      ..setPadding(padding);
   }
 }

lib/widgets/responsive_widget.dart

@@ -1,10 +1,6 @@
 import 'package:flutter/material.dart';
 
 class ResponsiveWidget extends StatelessWidget {
-  final Widget largeScreen;
-  final Widget? mediumScreen;
-  final Widget? smallScreen;
-
   const ResponsiveWidget({
     required this.largeScreen,
     this.mediumScreen,
@@ -12,6 +8,10 @@ class ResponsiveWidget extends StatelessWidget {
     Key? key,
   }) : super(key: key);
 
+  final Widget largeScreen;
+  final Widget? mediumScreen;
+  final Widget? smallScreen;
+
   static bool isSmallScreen(BuildContext context) {
     return MediaQuery.of(context).size.width < 800;
   }

lib/widgets/text_block.dart

@@ -1,19 +1,18 @@
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
-import 'package:flutter_quill/models/documents/attribute.dart';
-import 'package:flutter_quill/models/documents/nodes/block.dart';
-import 'package:flutter_quill/models/documents/nodes/line.dart';
-import 'package:flutter_quill/models/documents/nodes/node.dart';
-import 'package:flutter_quill/widgets/cursor.dart';
-import 'package:flutter_quill/widgets/default_styles.dart';
-import 'package:flutter_quill/widgets/text_line.dart';
-import 'package:flutter_quill/widgets/text_selection.dart';
 import 'package:tuple/tuple.dart';
 
+import '../models/documents/attribute.dart';
+import '../models/documents/nodes/block.dart';
+import '../models/documents/nodes/line.dart';
 import 'box.dart';
+import 'cursor.dart';
+import 'default_styles.dart';
 import 'delegate.dart';
 import 'editor.dart';
+import 'text_line.dart';
+import 'text_selection.dart';
 
 const List<int> arabianRomanNumbers = [
   1000,
@@ -48,6 +47,21 @@ const List<String> romanNumbers = [
 ];
 
 class EditableTextBlock extends StatelessWidget {
+  const EditableTextBlock(
+    this.block,
+    this.textDirection,
+    this.verticalSpacing,
+    this.textSelection,
+    this.color,
+    this.styles,
+    this.enableInteractiveSelection,
+    this.hasFocus,
+    this.contentPadding,
+    this.embedBuilder,
+    this.cursorCont,
+    this.indentLevelCounts,
+  );
+
   final Block block;
   final TextDirection textDirection;
   final Tuple2 verticalSpacing;
@@ -61,25 +75,11 @@ class EditableTextBlock extends StatelessWidget {
   final CursorCont cursorCont;
   final Map<int, int> indentLevelCounts;
 
-  const EditableTextBlock(
-      this.block,
-      this.textDirection,
-      this.verticalSpacing,
-      this.textSelection,
-      this.color,
-      this.styles,
-      this.enableInteractiveSelection,
-      this.hasFocus,
-      this.contentPadding,
-      this.embedBuilder,
-      this.cursorCont,
-      this.indentLevelCounts);
-
   @override
   Widget build(BuildContext context) {
     assert(debugCheckHasMediaQuery(context));
 
-    DefaultStyles? defaultStyles = QuillStyles.getStyles(context, false);
+    final defaultStyles = QuillStyles.getStyles(context, false);
     return _EditableBlock(
         block,
         textDirection,
@@ -91,7 +91,7 @@ class EditableTextBlock extends StatelessWidget {
 
   BoxDecoration? _getDecorationForBlock(
       Block node, DefaultStyles? defaultStyles) {
-    Map<String, Attribute> attrs = block.style.attributes;
+    final attrs = block.style.attributes;
     if (attrs.containsKey(Attribute.blockQuote.key)) {
       return defaultStyles!.quote!.decoration;
     }
@@ -103,13 +103,13 @@ class EditableTextBlock extends StatelessWidget {
 
   List<Widget> _buildChildren(
       BuildContext context, Map<int, int> indentLevelCounts) {
-    DefaultStyles? defaultStyles = QuillStyles.getStyles(context, false);
+    final defaultStyles = QuillStyles.getStyles(context, false);
-    int count = block.children.length;
+    final count = block.children.length;
-    var children = <Widget>[];
+    final children = <Widget>[];
-    int index = 0;
+    var index = 0;
-    for (Line line in Iterable.castFrom<dynamic, Line>(block.children)) {
+    for (final line in Iterable.castFrom<dynamic, Line>(block.children)) {
       index++;
-      EditableTextLine editableTextLine = EditableTextLine(
+      final editableTextLine = EditableTextLine(
           line,
           _buildLeading(context, line, index, indentLevelCounts, count),
           TextLine(
@@ -134,8 +134,8 @@ class EditableTextBlock extends StatelessWidget {
 
   Widget? _buildLeading(BuildContext context, Line line, int index,
       Map<int, int> indentLevelCounts, int count) {
-    DefaultStyles? defaultStyles = QuillStyles.getStyles(context, false);
+    final defaultStyles = QuillStyles.getStyles(context, false);
-    Map<String, Attribute> attrs = line.style.attributes;
+    final attrs = line.style.attributes;
     if (attrs[Attribute.list.key] == Attribute.ol) {
       return _NumberPoint(
         index: index,
@@ -143,8 +143,8 @@ class EditableTextBlock extends StatelessWidget {
         count: count,
         style: defaultStyles!.leading!.style,
         attrs: attrs,
-        width: 32.0,
+        width: 32,
-        padding: 8.0,
+        padding: 8,
       );
     }
 
@@ -173,9 +173,9 @@ class EditableTextBlock extends StatelessWidget {
         count: count,
         style: defaultStyles!.code!.style
             .copyWith(color: defaultStyles.code!.style.color!.withOpacity(0.4)),
-        width: 32.0,
+        width: 32,
         attrs: attrs,
-        padding: 16.0,
+        padding: 16,
         withDot: false,
       );
     }
@@ -183,10 +183,10 @@ class EditableTextBlock extends StatelessWidget {
   }
 
   double _getIndentWidth() {
-    Map<String, Attribute> attrs = block.style.attributes;
+    final attrs = block.style.attributes;
 
-    Attribute? indent = attrs[Attribute.indent.key];
+    final indent = attrs[Attribute.indent.key];
-    double extraIndent = 0.0;
+    var extraIndent = 0.0;
     if (indent != null && indent.value != null) {
       extraIndent = 16.0 * indent.value;
     }
@@ -200,11 +200,11 @@ class EditableTextBlock extends StatelessWidget {
 
   Tuple2 _getSpacingForLine(
       Line node, int index, int count, DefaultStyles? defaultStyles) {
-    double top = 0.0, bottom = 0.0;
+    var top = 0.0, bottom = 0.0;
 
-    Map<String, Attribute> attrs = block.style.attributes;
+    final attrs = block.style.attributes;
     if (attrs.containsKey(Attribute.header.key)) {
-      int? level = attrs[Attribute.header.key]!.value;
+      final level = attrs[Attribute.header.key]!.value;
       switch (level) {
         case 1:
           top = defaultStyles!.h1!.verticalSpacing.item1;
@@ -310,22 +310,22 @@ class RenderEditableTextBlock extends RenderEditableContainerBox
 
   @override
   TextRange getLineBoundary(TextPosition position) {
-    RenderEditableBox child = childAtPosition(position);
+    final child = childAtPosition(position);
-    TextRange rangeInChild = child.getLineBoundary(TextPosition(
+    final rangeInChild = child.getLineBoundary(TextPosition(
-      offset: position.offset - child.getContainer().getOffset(),
+      offset: position.offset - child.getContainer().offset,
       affinity: position.affinity,
     ));
     return TextRange(
-      start: rangeInChild.start + child.getContainer().getOffset(),
+      start: rangeInChild.start + child.getContainer().offset,
-      end: rangeInChild.end + child.getContainer().getOffset(),
+      end: rangeInChild.end + child.getContainer().offset,
     );
   }
 
   @override
   Offset getOffsetForCaret(TextPosition position) {
-    RenderEditableBox child = childAtPosition(position);
+    final child = childAtPosition(position);
     return child.getOffsetForCaret(TextPosition(
-          offset: position.offset - child.getContainer().getOffset(),
+          offset: position.offset - child.getContainer().offset,
           affinity: position.affinity,
         )) +
         (child.parentData as BoxParentData).offset;
@@ -333,21 +333,21 @@ class RenderEditableTextBlock extends RenderEditableContainerBox
 
   @override
   TextPosition getPositionForOffset(Offset offset) {
-    RenderEditableBox child = childAtOffset(offset)!;
+    final child = childAtOffset(offset)!;
-    BoxParentData parentData = child.parentData as BoxParentData;
+    final parentData = child.parentData as BoxParentData;
-    TextPosition localPosition =
+    final localPosition =
         child.getPositionForOffset(offset - parentData.offset);
     return TextPosition(
-      offset: localPosition.offset + child.getContainer().getOffset(),
+      offset: localPosition.offset + child.getContainer().offset,
       affinity: localPosition.affinity,
     );
   }
 
   @override
   TextRange getWordBoundary(TextPosition position) {
-    RenderEditableBox child = childAtPosition(position);
+    final child = childAtPosition(position);
-    int nodeOffset = child.getContainer().getOffset();
+    final nodeOffset = child.getContainer().offset;
-    TextRange childWord = child
+    final childWord = child
         .getWordBoundary(TextPosition(offset: position.offset - nodeOffset));
     return TextRange(
       start: childWord.start + nodeOffset,
@@ -359,27 +359,26 @@ class RenderEditableTextBlock extends RenderEditableContainerBox
   TextPosition? getPositionAbove(TextPosition position) {
     assert(position.offset < getContainer().length);
 
-    RenderEditableBox child = childAtPosition(position);
+    final child = childAtPosition(position);
-    TextPosition childLocalPosition = TextPosition(
+    final childLocalPosition =
-        offset: position.offset - child.getContainer().getOffset());
+        TextPosition(offset: position.offset - child.getContainer().offset);
-    TextPosition? result = child.getPositionAbove(childLocalPosition);
+    final result = child.getPositionAbove(childLocalPosition);
     if (result != null) {
-      return TextPosition(
+      return TextPosition(offset: result.offset + child.getContainer().offset);
-          offset: result.offset + child.getContainer().getOffset());
     }
 
-    RenderEditableBox? sibling = childBefore(child);
+    final sibling = childBefore(child);
     if (sibling == null) {
       return null;
     }
 
-    Offset caretOffset = child.getOffsetForCaret(childLocalPosition);
+    final caretOffset = child.getOffsetForCaret(childLocalPosition);
-    TextPosition testPosition =
+    final testPosition =
         TextPosition(offset: sibling.getContainer().length - 1);
-    Offset testOffset = sibling.getOffsetForCaret(testPosition);
+    final testOffset = sibling.getOffsetForCaret(testPosition);
-    Offset finalOffset = Offset(caretOffset.dx, testOffset.dy);
+    final finalOffset = Offset(caretOffset.dx, testOffset.dy);
     return TextPosition(
-        offset: sibling.getContainer().getOffset() +
+        offset: sibling.getContainer().offset +
             sibling.getPositionForOffset(finalOffset).offset);
   }
 
@@ -387,46 +386,44 @@ class RenderEditableTextBlock extends RenderEditableContainerBox
   TextPosition? getPositionBelow(TextPosition position) {
     assert(position.offset < getContainer().length);
 
-    RenderEditableBox child = childAtPosition(position);
+    final child = childAtPosition(position);
-    TextPosition childLocalPosition = TextPosition(
+    final childLocalPosition =
-        offset: position.offset - child.getContainer().getOffset());
+        TextPosition(offset: position.offset - child.getContainer().offset);
-    TextPosition? result = child.getPositionBelow(childLocalPosition);
+    final result = child.getPositionBelow(childLocalPosition);
     if (result != null) {
-      return TextPosition(
+      return TextPosition(offset: result.offset + child.getContainer().offset);
-          offset: result.offset + child.getContainer().getOffset());
     }
 
-    RenderEditableBox? sibling = childAfter(child);
+    final sibling = childAfter(child);
     if (sibling == null) {
       return null;
     }
 
-    Offset caretOffset = child.getOffsetForCaret(childLocalPosition);
+    final caretOffset = child.getOffsetForCaret(childLocalPosition);
-    Offset testOffset =
+    final testOffset = sibling.getOffsetForCaret(const TextPosition(offset: 0));
-        sibling.getOffsetForCaret(const TextPosition(offset: 0));
+    final finalOffset = Offset(caretOffset.dx, testOffset.dy);
-    Offset finalOffset = Offset(caretOffset.dx, testOffset.dy);
     return TextPosition(
-        offset: sibling.getContainer().getOffset() +
+        offset: sibling.getContainer().offset +
             sibling.getPositionForOffset(finalOffset).offset);
   }
 
   @override
   double preferredLineHeight(TextPosition position) {
-    RenderEditableBox child = childAtPosition(position);
+    final child = childAtPosition(position);
-    return child.preferredLineHeight(TextPosition(
+    return child.preferredLineHeight(
-        offset: position.offset - child.getContainer().getOffset()));
+        TextPosition(offset: position.offset - child.getContainer().offset));
   }
 
   @override
   TextSelectionPoint getBaseEndpointForSelection(TextSelection selection) {
     if (selection.isCollapsed) {
       return TextSelectionPoint(
-          Offset(0.0, preferredLineHeight(selection.extent)) +
+          Offset(0, preferredLineHeight(selection.extent)) +
               getOffsetForCaret(selection.extent),
           null);
     }
 
-    Node? baseNode = getContainer().queryChild(selection.start, false).node;
+    final baseNode = getContainer().queryChild(selection.start, false).node;
     var baseChild = firstChild;
     while (baseChild != null) {
       if (baseChild.getContainer() == baseNode) {
@@ -436,7 +433,7 @@ class RenderEditableTextBlock extends RenderEditableContainerBox
     }
     assert(baseChild != null);
 
-    TextSelectionPoint basePoint = baseChild!.getBaseEndpointForSelection(
+    final basePoint = baseChild!.getBaseEndpointForSelection(
         localSelection(baseChild.getContainer(), selection, true));
     return TextSelectionPoint(
         basePoint.point + (baseChild.parentData as BoxParentData).offset,
@@ -447,12 +444,12 @@ class RenderEditableTextBlock extends RenderEditableContainerBox
   TextSelectionPoint getExtentEndpointForSelection(TextSelection selection) {
     if (selection.isCollapsed) {
       return TextSelectionPoint(
-          Offset(0.0, preferredLineHeight(selection.extent)) +
+          Offset(0, preferredLineHeight(selection.extent)) +
               getOffsetForCaret(selection.extent),
           null);
     }
 
-    Node? extentNode = getContainer().queryChild(selection.end, false).node;
+    final extentNode = getContainer().queryChild(selection.end, false).node;
 
     var extentChild = firstChild;
     while (extentChild != null) {
@@ -463,7 +460,7 @@ class RenderEditableTextBlock extends RenderEditableContainerBox
     }
     assert(extentChild != null);
 
-    TextSelectionPoint extentPoint = extentChild!.getExtentEndpointForSelection(
+    final extentPoint = extentChild!.getExtentEndpointForSelection(
         localSelection(extentChild.getContainer(), selection, true));
     return TextSelectionPoint(
         extentPoint.point + (extentChild.parentData as BoxParentData).offset,
@@ -487,11 +484,11 @@ class RenderEditableTextBlock extends RenderEditableContainerBox
   void _paintDecoration(PaintingContext context, Offset offset) {
     _painter ??= _decoration.createBoxPainter(markNeedsPaint);
 
-    EdgeInsets decorationPadding = resolvedPadding! - _contentPadding;
+    final decorationPadding = resolvedPadding! - _contentPadding;
 
-    ImageConfiguration filledConfiguration =
+    final filledConfiguration =
         configuration.copyWith(size: decorationPadding.deflateSize(size));
-    int debugSaveCount = context.canvas.getSaveCount();
+    final debugSaveCount = context.canvas.getSaveCount();
 
     final decorationOffset =
         offset.translate(decorationPadding.left, decorationPadding.top);
@@ -511,16 +508,21 @@ class RenderEditableTextBlock extends RenderEditableContainerBox
 }
 
 class _EditableBlock extends MultiChildRenderObjectWidget {
+  _EditableBlock(
+    this.block,
+    this.textDirection,
+    this.padding,
+    this.decoration,
+    this.contentPadding,
+    List<Widget> children,
+  ) : super(children: children);
+
   final Block block;
   final TextDirection textDirection;
   final Tuple2<double, double> padding;
   final Decoration decoration;
   final EdgeInsets? contentPadding;
 
-  _EditableBlock(this.block, this.textDirection, this.padding, this.decoration,
-      this.contentPadding, List<Widget> children)
-      : super(children: children);
-
   EdgeInsets get _padding =>
       EdgeInsets.only(top: padding.item1, bottom: padding.item2);
 
@@ -540,24 +542,16 @@ class _EditableBlock extends MultiChildRenderObjectWidget {
   @override
   void updateRenderObject(
       BuildContext context, covariant RenderEditableTextBlock renderObject) {
-    renderObject.setContainer(block);
+    renderObject
-    renderObject.textDirection = textDirection;
+      ..setContainer(block)
-    renderObject.setPadding(_padding);
+      ..textDirection = textDirection
-    renderObject.decoration = decoration;
+      ..setPadding(_padding)
-    renderObject.contentPadding = _contentPadding;
+      ..decoration = decoration
+      ..contentPadding = _contentPadding;
   }
 }
 
 class _NumberPoint extends StatelessWidget {
-  final int index;
-  final Map<int?, int> indentLevelCounts;
-  final int count;
-  final TextStyle style;
-  final double width;
-  final Map<String, Attribute> attrs;
-  final bool withDot;
-  final double padding;
-
   const _NumberPoint({
     required this.index,
     required this.indentLevelCounts,
@@ -570,9 +564,18 @@ class _NumberPoint extends StatelessWidget {
     Key? key,
   }) : super(key: key);
 
+  final int index;
+  final Map<int?, int> indentLevelCounts;
+  final int count;
+  final TextStyle style;
+  final double width;
+  final Map<String, Attribute> attrs;
+  final bool withDot;
+  final double padding;
+
   @override
   Widget build(BuildContext context) {
-    String s = index.toString();
+    var s = index.toString();
     int? level = 0;
     if (!attrs.containsKey(Attribute.indent.key) &&
         !indentLevelCounts.containsKey(1)) {
@@ -581,7 +584,7 @@ class _NumberPoint extends StatelessWidget {
         alignment: AlignmentDirectional.topEnd,
         width: width,
         padding: EdgeInsetsDirectional.only(end: padding),
-        child: Text(withDot ? '$s.' : '$s', style: style),
+        child: Text(withDot ? '$s.' : s, style: style),
       );
     }
     if (attrs.containsKey(Attribute.indent.key)) {
@@ -595,7 +598,7 @@ class _NumberPoint extends StatelessWidget {
       // last visited level is done, going up
       indentLevelCounts.remove(level + 1);
     }
-    int count = (indentLevelCounts[level] ?? 0) + 1;
+    final count = (indentLevelCounts[level] ?? 0) + 1;
     indentLevelCounts[level] = count;
 
     s = count.toString();
@@ -612,7 +615,7 @@ class _NumberPoint extends StatelessWidget {
       alignment: AlignmentDirectional.topEnd,
       width: width,
       padding: EdgeInsetsDirectional.only(end: padding),
-      child: Text(withDot ? '$s.' : '$s', style: style),
+      child: Text(withDot ? '$s.' : s, style: style),
     );
   }
 
@@ -653,33 +656,34 @@ class _NumberPoint extends StatelessWidget {
 }
 
 class _BulletPoint extends StatelessWidget {
-  final TextStyle style;
-  final double width;
-
   const _BulletPoint({
     required this.style,
     required this.width,
     Key? key,
   }) : super(key: key);
 
+  final TextStyle style;
+  final double width;
+
   @override
   Widget build(BuildContext context) {
     return Container(
       alignment: AlignmentDirectional.topEnd,
       width: width,
-      padding: const EdgeInsetsDirectional.only(end: 13.0),
+      padding: const EdgeInsetsDirectional.only(end: 13),
       child: Text('•', style: style),
     );
   }
 }
 
 class _Checkbox extends StatefulWidget {
+  const _Checkbox({Key? key, this.style, this.width, this.isChecked})
+      : super(key: key);
+
   final TextStyle? style;
   final double? width;
   final bool? isChecked;
 
-  const _Checkbox({Key? key, this.style, this.width, this.isChecked})
-      : super(key: key);
   @override
   __CheckboxState createState() => __CheckboxState();
 }
@@ -708,7 +712,7 @@ class __CheckboxState extends State<_Checkbox> {
     return Container(
       alignment: AlignmentDirectional.topEnd,
       width: widget.width,
-      padding: const EdgeInsetsDirectional.only(end: 13.0),
+      padding: const EdgeInsetsDirectional.only(end: 13),
       child: Checkbox(
         value: widget.isChecked,
         onChanged: _onCheckboxClicked,

lib/widgets/text_line.dart

@@ -3,30 +3,23 @@ import 'dart:math' as math;
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
-import 'package:flutter_quill/models/documents/attribute.dart';
-import 'package:flutter_quill/models/documents/nodes/container.dart'
-    as container;
-import 'package:flutter_quill/models/documents/nodes/leaf.dart' as leaf;
-import 'package:flutter_quill/models/documents/nodes/leaf.dart';
-import 'package:flutter_quill/models/documents/nodes/line.dart';
-import 'package:flutter_quill/models/documents/nodes/node.dart';
-import 'package:flutter_quill/models/documents/style.dart';
-import 'package:flutter_quill/utils/color.dart';
-import 'package:flutter_quill/widgets/cursor.dart';
-import 'package:flutter_quill/widgets/proxy.dart';
-import 'package:flutter_quill/widgets/text_selection.dart';
 import 'package:tuple/tuple.dart';
 
+import '../models/documents/attribute.dart';
+import '../models/documents/nodes/container.dart' as container;
+import '../models/documents/nodes/leaf.dart' as leaf;
+import '../models/documents/nodes/leaf.dart';
+import '../models/documents/nodes/line.dart';
+import '../models/documents/nodes/node.dart';
+import '../utils/color.dart';
 import 'box.dart';
+import 'cursor.dart';
 import 'default_styles.dart';
 import 'delegate.dart';
+import 'proxy.dart';
+import 'text_selection.dart';
 
 class TextLine extends StatelessWidget {
-  final Line line;
-  final TextDirection? textDirection;
-  final EmbedBuilder embedBuilder;
-  final DefaultStyles styles;
-
   const TextLine({
     required this.line,
     required this.embedBuilder,
@@ -35,21 +28,25 @@ class TextLine extends StatelessWidget {
     Key? key,
   }) : super(key: key);
 
+  final Line line;
+  final TextDirection? textDirection;
+  final EmbedBuilder embedBuilder;
+  final DefaultStyles styles;
+
   @override
   Widget build(BuildContext context) {
     assert(debugCheckHasMediaQuery(context));
 
     if (line.hasEmbed) {
-      Embed embed = line.children.single as Embed;
+      final embed = line.children.single as Embed;
       return EmbedProxy(embedBuilder(context, embed));
     }
 
-    TextSpan textSpan = _buildTextSpan(context);
+    final textSpan = _buildTextSpan(context);
-    StrutStyle strutStyle =
+    final strutStyle = StrutStyle.fromTextStyle(textSpan.style!);
-        StrutStyle.fromTextStyle(textSpan.style!, forceStrutHeight: true);
     final textAlign = _getTextAlign();
-    RichText child = RichText(
+    final child = RichText(
-      text: TextSpan(children: [textSpan]),
+      text: textSpan,
       textAlign: textAlign,
       textDirection: textDirection,
       strutStyle: strutStyle,
@@ -60,7 +57,7 @@ class TextLine extends StatelessWidget {
         textSpan.style!,
         textAlign,
         textDirection!,
-        1.0,
+        1,
         Localizations.localeOf(context),
         strutStyle,
         TextWidthBasis.parent,
@@ -82,20 +79,20 @@ class TextLine extends StatelessWidget {
   }
 
   TextSpan _buildTextSpan(BuildContext context) {
-    DefaultStyles defaultStyles = styles;
+    final defaultStyles = styles;
-    List<TextSpan> children = line.children
+    final children = line.children
         .map((node) => _getTextSpanFromNode(defaultStyles, node))
         .toList(growable: false);
 
-    TextStyle textStyle = const TextStyle();
+    var textStyle = const TextStyle();
 
     if (line.style.containsKey(Attribute.placeholder.key)) {
       textStyle = defaultStyles.placeHolder!.style;
       return TextSpan(children: children, style: textStyle);
     }
 
-    Attribute? header = line.style.attributes[Attribute.header.key];
+    final header = line.style.attributes[Attribute.header.key];
-    Map<Attribute, TextStyle> m = {
+    final m = <Attribute, TextStyle>{
       Attribute.h1: defaultStyles.h1!.style,
       Attribute.h2: defaultStyles.h2!.style,
       Attribute.h3: defaultStyles.h3!.style,
@@ -103,7 +100,7 @@ class TextLine extends StatelessWidget {
 
     textStyle = textStyle.merge(m[header] ?? defaultStyles.paragraph!.style);
 
-    Attribute? block = line.style.getBlockExceptHeader();
+    final block = line.style.getBlockExceptHeader();
     TextStyle? toMerge;
     if (block == Attribute.blockQuote) {
       toMerge = defaultStyles.quote!.style;
@@ -119,29 +116,28 @@ class TextLine extends StatelessWidget {
   }
 
   TextSpan _getTextSpanFromNode(DefaultStyles defaultStyles, Node node) {
-    leaf.Text textNode = node as leaf.Text;
+    final textNode = node as leaf.Text;
-    Style style = textNode.style;
+    final style = textNode.style;
-    TextStyle res = const TextStyle();
+    var res = const TextStyle();
 
-    Map<String, TextStyle?> m = {
+    <String, TextStyle?>{
       Attribute.bold.key: defaultStyles.bold,
       Attribute.italic.key: defaultStyles.italic,
       Attribute.link.key: defaultStyles.link,
       Attribute.underline.key: defaultStyles.underline,
       Attribute.strikeThrough.key: defaultStyles.strikeThrough,
-    };
+    }.forEach((k, s) {
-    m.forEach((k, s) {
       if (style.values.any((v) => v.key == k)) {
         res = _merge(res, s!);
       }
     });
 
-    Attribute? font = textNode.style.attributes[Attribute.font.key];
+    final font = textNode.style.attributes[Attribute.font.key];
     if (font != null && font.value != null) {
       res = res.merge(TextStyle(fontFamily: font.value));
     }
 
-    Attribute? size = textNode.style.attributes[Attribute.size.key];
+    final size = textNode.style.attributes[Attribute.size.key];
     if (size != null && size.value != null) {
       switch (size.value) {
         case 'small':
@@ -154,7 +150,7 @@ class TextLine extends StatelessWidget {
           res = res.merge(defaultStyles.sizeHuge);
           break;
         default:
-          double? fontSize = double.tryParse(size.value);
+          final fontSize = double.tryParse(size.value);
           if (fontSize != null) {
             res = res.merge(TextStyle(fontSize: fontSize));
           } else {
@@ -163,7 +159,7 @@ class TextLine extends StatelessWidget {
       }
     }
 
-    Attribute? color = textNode.style.attributes[Attribute.color.key];
+    final color = textNode.style.attributes[Attribute.color.key];
     if (color != null && color.value != null) {
       var textColor = defaultStyles.color;
       if (color.value is String) {
@@ -174,7 +170,7 @@ class TextLine extends StatelessWidget {
       }
     }
 
-    Attribute? background = textNode.style.attributes[Attribute.background.key];
+    final background = textNode.style.attributes[Attribute.background.key];
     if (background != null && background.value != null) {
       final backgroundColor = stringToColor(background.value);
       res = res.merge(TextStyle(backgroundColor: backgroundColor));
@@ -198,6 +194,21 @@ class TextLine extends StatelessWidget {
 }
 
 class EditableTextLine extends RenderObjectWidget {
+  const EditableTextLine(
+    this.line,
+    this.leading,
+    this.body,
+    this.indentWidth,
+    this.verticalSpacing,
+    this.textDirection,
+    this.textSelection,
+    this.color,
+    this.enableInteractiveSelection,
+    this.hasFocus,
+    this.devicePixelRatio,
+    this.cursorCont,
+  );
+
   final Line line;
   final Widget? leading;
   final Widget body;
@@ -211,20 +222,6 @@ class EditableTextLine extends RenderObjectWidget {
   final double devicePixelRatio;
   final CursorCont cursorCont;
 
-  const EditableTextLine(
-      this.line,
-      this.leading,
-      this.body,
-      this.indentWidth,
-      this.verticalSpacing,
-      this.textDirection,
-      this.textSelection,
-      this.color,
-      this.enableInteractiveSelection,
-      this.hasFocus,
-      this.devicePixelRatio,
-      this.cursorCont);
-
   @override
   RenderObjectElement createElement() {
     return _TextLineElement(this);
@@ -247,15 +244,16 @@ class EditableTextLine extends RenderObjectWidget {
   @override
   void updateRenderObject(
       BuildContext context, covariant RenderEditableTextLine renderObject) {
-    renderObject.setLine(line);
+    renderObject
-    renderObject.setPadding(_getPadding());
+      ..setLine(line)
-    renderObject.setTextDirection(textDirection);
+      ..setPadding(_getPadding())
-    renderObject.setTextSelection(textSelection);
+      ..setTextDirection(textDirection)
-    renderObject.setColor(color);
+      ..setTextSelection(textSelection)
-    renderObject.setEnableInteractiveSelection(enableInteractiveSelection);
+      ..setColor(color)
-    renderObject.hasFocus = hasFocus;
+      ..setEnableInteractiveSelection(enableInteractiveSelection)
-    renderObject.setDevicePixelRatio(devicePixelRatio);
+      ..hasFocus = hasFocus
-    renderObject.setCursorCont(cursorCont);
+      ..setDevicePixelRatio(devicePixelRatio)
+      ..setCursorCont(cursorCont);
   }
 
   EdgeInsetsGeometry _getPadding() {
@@ -269,6 +267,18 @@ class EditableTextLine extends RenderObjectWidget {
 enum TextLineSlot { LEADING, BODY }
 
 class RenderEditableTextLine extends RenderEditableBox {
+  RenderEditableTextLine(
+    this.line,
+    this.textDirection,
+    this.textSelection,
+    this.enableInteractiveSelection,
+    this.hasFocus,
+    this.devicePixelRatio,
+    this.padding,
+    this.color,
+    this.cursorCont,
+  );
+
   RenderBox? _leading;
   RenderContentProxyBox? _body;
   Line line;
@@ -286,17 +296,6 @@ class RenderEditableTextLine extends RenderEditableBox {
   Rect? _caretPrototype;
   final Map<TextLineSlot, RenderBox> children = <TextLineSlot, RenderBox>{};
 
-  RenderEditableTextLine(
-      this.line,
-      this.textDirection,
-      this.textSelection,
-      this.enableInteractiveSelection,
-      this.hasFocus,
-      this.devicePixelRatio,
-      this.padding,
-      this.color,
-      this.cursorCont);
-
   Iterable<RenderBox> get _children sync* {
     if (_leading != null) {
       yield _leading!;
@@ -347,7 +346,7 @@ class RenderEditableTextLine extends RenderEditableBox {
       return;
     }
 
-    bool containsSelection = containsTextSelection();
+    final containsSelection = containsTextSelection();
     if (attached && containsCursor()) {
       cursorCont.removeListener(markNeedsLayout);
       cursorCont.color.removeListener(markNeedsPaint);
@@ -403,8 +402,8 @@ class RenderEditableTextLine extends RenderEditableBox {
   }
 
   bool containsTextSelection() {
-    return line.getDocumentOffset() <= textSelection.end &&
+    return line.documentOffset <= textSelection.end &&
-        textSelection.start <= line.getDocumentOffset() + line.length - 1;
+        textSelection.start <= line.documentOffset + line.length - 1;
   }
 
   bool containsCursor() {
@@ -426,7 +425,7 @@ class RenderEditableTextLine extends RenderEditableBox {
   }
 
   List<TextBox> _getBoxes(TextSelection textSelection) {
-    BoxParentData? parentData = _body!.parentData as BoxParentData?;
+    final parentData = _body!.parentData as BoxParentData?;
     return _body!.getBoxesForSelection(textSelection).map((box) {
       return TextBox.fromLTRBD(
         box.left + parentData!.offset.dx,
@@ -461,13 +460,13 @@ class RenderEditableTextLine extends RenderEditableBox {
       TextSelection textSelection, bool first) {
     if (textSelection.isCollapsed) {
       return TextSelectionPoint(
-          Offset(0.0, preferredLineHeight(textSelection.extent)) +
+          Offset(0, preferredLineHeight(textSelection.extent)) +
               getOffsetForCaret(textSelection.extent),
           null);
     }
-    List<TextBox> boxes = _getBoxes(textSelection);
+    final boxes = _getBoxes(textSelection);
     assert(boxes.isNotEmpty);
-    TextBox targetBox = first ? boxes.first : boxes.last;
+    final targetBox = first ? boxes.first : boxes.last;
     return TextSelectionPoint(
         Offset(first ? targetBox.start : targetBox.end, targetBox.bottom),
         targetBox.direction);
@@ -475,10 +474,10 @@ class RenderEditableTextLine extends RenderEditableBox {
 
   @override
   TextRange getLineBoundary(TextPosition position) {
-    double lineDy = getOffsetForCaret(position)
+    final lineDy = getOffsetForCaret(position)
-        .translate(0.0, 0.5 * preferredLineHeight(position))
+        .translate(0, 0.5 * preferredLineHeight(position))
         .dy;
-    List<TextBox> lineBoxes =
+    final lineBoxes =
         _getBoxes(TextSelection(baseOffset: 0, extentOffset: line.length - 1))
             .where((element) => element.top < lineDy && element.bottom > lineDy)
             .toList(growable: false);
@@ -506,7 +505,7 @@ class RenderEditableTextLine extends RenderEditableBox {
 
   TextPosition? _getPosition(TextPosition textPosition, double dyScale) {
     assert(textPosition.offset < line.length);
-    Offset offset = getOffsetForCaret(textPosition)
+    final offset = getOffsetForCaret(textPosition)
         .translate(0, dyScale * preferredLineHeight(textPosition));
     if (_body!.size
         .contains(offset - (_body!.parentData as BoxParentData).offset)) {
@@ -546,15 +545,13 @@ class RenderEditableTextLine extends RenderEditableBox {
     switch (defaultTargetPlatform) {
       case TargetPlatform.iOS:
       case TargetPlatform.macOS:
-        _caretPrototype =
+        _caretPrototype = Rect.fromLTWH(0, 0, cursorWidth, cursorHeight + 2);
-            Rect.fromLTWH(0.0, 0.0, cursorWidth, cursorHeight + 2);
         break;
       case TargetPlatform.android:
       case TargetPlatform.fuchsia:
       case TargetPlatform.linux:
       case TargetPlatform.windows:
-        _caretPrototype =
+        _caretPrototype = Rect.fromLTWH(0, 2, cursorWidth, cursorHeight - 4.0);
-            Rect.fromLTWH(0.0, 2.0, cursorWidth, cursorHeight - 4.0);
         break;
       default:
         throw 'Invalid platform';
@@ -576,7 +573,7 @@ class RenderEditableTextLine extends RenderEditableBox {
   @override
   void detach() {
     super.detach();
-    for (RenderBox child in _children) {
+    for (final child in _children) {
       child.detach();
     }
     if (containsCursor()) {
@@ -597,7 +594,7 @@ class RenderEditableTextLine extends RenderEditableBox {
 
   @override
   List<DiagnosticsNode> debugDescribeChildren() {
-    var value = <DiagnosticsNode>[];
+    final value = <DiagnosticsNode>[];
     void add(RenderBox? child, String name) {
       if (child != null) {
         value.add(child.toDiagnosticsNode(name: name));
@@ -615,14 +612,14 @@ class RenderEditableTextLine extends RenderEditableBox {
   @override
   double computeMinIntrinsicWidth(double height) {
     _resolvePadding();
-    double horizontalPadding = _resolvedPadding!.left + _resolvedPadding!.right;
+    final horizontalPadding = _resolvedPadding!.left + _resolvedPadding!.right;
-    double verticalPadding = _resolvedPadding!.top + _resolvedPadding!.bottom;
+    final verticalPadding = _resolvedPadding!.top + _resolvedPadding!.bottom;
-    int leadingWidth = _leading == null
+    final leadingWidth = _leading == null
         ? 0
         : _leading!.getMinIntrinsicWidth(height - verticalPadding) as int;
-    int bodyWidth = _body == null
+    final bodyWidth = _body == null
         ? 0
-        : _body!.getMinIntrinsicWidth(math.max(0.0, height - verticalPadding))
+        : _body!.getMinIntrinsicWidth(math.max(0, height - verticalPadding))
             as int;
     return horizontalPadding + leadingWidth + bodyWidth;
   }
@@ -630,14 +627,14 @@ class RenderEditableTextLine extends RenderEditableBox {
   @override
   double computeMaxIntrinsicWidth(double height) {
     _resolvePadding();
-    double horizontalPadding = _resolvedPadding!.left + _resolvedPadding!.right;
+    final horizontalPadding = _resolvedPadding!.left + _resolvedPadding!.right;
-    double verticalPadding = _resolvedPadding!.top + _resolvedPadding!.bottom;
+    final verticalPadding = _resolvedPadding!.top + _resolvedPadding!.bottom;
-    int leadingWidth = _leading == null
+    final leadingWidth = _leading == null
         ? 0
         : _leading!.getMaxIntrinsicWidth(height - verticalPadding) as int;
-    int bodyWidth = _body == null
+    final bodyWidth = _body == null
         ? 0
-        : _body!.getMaxIntrinsicWidth(math.max(0.0, height - verticalPadding))
+        : _body!.getMaxIntrinsicWidth(math.max(0, height - verticalPadding))
             as int;
     return horizontalPadding + leadingWidth + bodyWidth;
   }
@@ -645,11 +642,11 @@ class RenderEditableTextLine extends RenderEditableBox {
   @override
   double computeMinIntrinsicHeight(double width) {
     _resolvePadding();
-    double horizontalPadding = _resolvedPadding!.left + _resolvedPadding!.right;
+    final horizontalPadding = _resolvedPadding!.left + _resolvedPadding!.right;
-    double verticalPadding = _resolvedPadding!.top + _resolvedPadding!.bottom;
+    final verticalPadding = _resolvedPadding!.top + _resolvedPadding!.bottom;
     if (_body != null) {
       return _body!
-              .getMinIntrinsicHeight(math.max(0.0, width - horizontalPadding)) +
+              .getMinIntrinsicHeight(math.max(0, width - horizontalPadding)) +
           verticalPadding;
     }
     return verticalPadding;
@@ -658,11 +655,11 @@ class RenderEditableTextLine extends RenderEditableBox {
   @override
   double computeMaxIntrinsicHeight(double width) {
     _resolvePadding();
-    double horizontalPadding = _resolvedPadding!.left + _resolvedPadding!.right;
+    final horizontalPadding = _resolvedPadding!.left + _resolvedPadding!.right;
-    double verticalPadding = _resolvedPadding!.top + _resolvedPadding!.bottom;
+    final verticalPadding = _resolvedPadding!.top + _resolvedPadding!.bottom;
     if (_body != null) {
       return _body!
-              .getMaxIntrinsicHeight(math.max(0.0, width - horizontalPadding)) +
+              .getMaxIntrinsicHeight(math.max(0, width - horizontalPadding)) +
           verticalPadding;
     }
     return verticalPadding;
@@ -697,8 +694,7 @@ class RenderEditableTextLine extends RenderEditableBox {
         : _resolvedPadding!.right;
 
     _body!.layout(innerConstraints, parentUsesSize: true);
-    final bodyParentData = _body!.parentData as BoxParentData;
+    (_body!.parentData as BoxParentData).offset =
-    bodyParentData.offset =
         Offset(_resolvedPadding!.left, _resolvedPadding!.top);
 
     if (_leading != null) {
@@ -707,8 +703,8 @@ class RenderEditableTextLine extends RenderEditableBox {
           maxWidth: indentWidth,
           maxHeight: _body!.size.height);
       _leading!.layout(leadingConstraints, parentUsesSize: true);
-      final parentData = _leading!.parentData as BoxParentData;
+      (_leading!.parentData as BoxParentData).offset =
-      parentData.offset = Offset(0.0, _resolvedPadding!.top);
+          Offset(0, _resolvedPadding!.top);
     }
 
     size = constraints.constrain(Size(
@@ -739,8 +735,8 @@ class RenderEditableTextLine extends RenderEditableBox {
       final parentData = _body!.parentData as BoxParentData;
       final effectiveOffset = offset + parentData.offset;
       if (enableInteractiveSelection &&
-          line.getDocumentOffset() <= textSelection.end &&
+          line.documentOffset <= textSelection.end &&
-          textSelection.start <= line.getDocumentOffset() + line.length - 1) {
+          textSelection.start <= line.documentOffset + line.length - 1) {
         final local = localSelection(line, textSelection, false);
         _selectedRects ??= _body!.getBoxesForSelection(
           local,
@@ -776,7 +772,7 @@ class RenderEditableTextLine extends RenderEditableBox {
 
   void _paintCursor(PaintingContext context, Offset effectiveOffset) {
     final position = TextPosition(
-      offset: textSelection.extentOffset - line.getDocumentOffset(),
+      offset: textSelection.extentOffset - line.documentOffset,
       affinity: textSelection.base.affinity,
     );
     _cursorPainter.paint(context.canvas, effectiveOffset, position);
@@ -851,8 +847,8 @@ class _TextLineElement extends RenderObjectElement {
   }
 
   void _mountChild(Widget? widget, TextLineSlot slot) {
-    Element? oldChild = _slotToChildren[slot];
+    final oldChild = _slotToChildren[slot];
-    Element? newChild = updateChild(oldChild, widget, slot);
+    final newChild = updateChild(oldChild, widget, slot);
     if (oldChild != null) {
       _slotToChildren.remove(slot);
     }
@@ -875,8 +871,8 @@ class _TextLineElement extends RenderObjectElement {
   }
 
   void _updateChild(Widget? widget, TextLineSlot slot) {
-    Element? oldChild = _slotToChildren[slot];
+    final oldChild = _slotToChildren[slot];
-    Element? newChild = updateChild(oldChild, widget, slot);
+    final newChild = updateChild(oldChild, widget, slot);
     if (oldChild != null) {
       _slotToChildren.remove(slot);
     }

lib/widgets/text_selection.dart

@@ -7,15 +7,15 @@ import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/scheduler.dart';
-import 'package:flutter_quill/models/documents/nodes/node.dart';
 
+import '../models/documents/nodes/node.dart';
 import 'editor.dart';
 
 TextSelection localSelection(Node node, TextSelection selection, fromParent) {
-  int base = fromParent ? node.getOffset() : node.getDocumentOffset();
+  final base = fromParent ? node.offset : node.documentOffset;
   assert(base <= selection.end && selection.start <= base + node.length - 1);
 
-  int offset = fromParent ? node.getOffset() : node.getDocumentOffset();
+  final offset = fromParent ? node.offset : node.documentOffset;
   return selection.copyWith(
       baseOffset: math.max(selection.start - offset, 0),
       extentOffset: math.min(selection.end - offset, node.length - 1));
@@ -24,6 +24,27 @@ TextSelection localSelection(Node node, TextSelection selection, fromParent) {
 enum _TextSelectionHandlePosition { START, END }
 
 class EditorTextSelectionOverlay {
+  EditorTextSelectionOverlay(
+    this.value,
+    this.handlesVisible,
+    this.context,
+    this.debugRequiredFor,
+    this.toolbarLayerLink,
+    this.startHandleLayerLink,
+    this.endHandleLayerLink,
+    this.renderObject,
+    this.selectionCtrls,
+    this.selectionDelegate,
+    this.dragStartBehavior,
+    this.onSelectionHandleTapped,
+    this.clipboardStatus,
+  ) {
+    final overlay = Overlay.of(context, rootOverlay: true)!;
+
+    _toolbarController = AnimationController(
+        duration: const Duration(milliseconds: 150), vsync: overlay);
+  }
+
   TextEditingValue value;
   bool handlesVisible = false;
   final BuildContext context;
@@ -41,26 +62,6 @@ class EditorTextSelectionOverlay {
   List<OverlayEntry>? _handles;
   OverlayEntry? toolbar;
 
-  EditorTextSelectionOverlay(
-      this.value,
-      this.handlesVisible,
-      this.context,
-      this.debugRequiredFor,
-      this.toolbarLayerLink,
-      this.startHandleLayerLink,
-      this.endHandleLayerLink,
-      this.renderObject,
-      this.selectionCtrls,
-      this.selectionDelegate,
-      this.dragStartBehavior,
-      this.onSelectionHandleTapped,
-      this.clipboardStatus) {
-    OverlayState overlay = Overlay.of(context, rootOverlay: true)!;
-
-    _toolbarController = AnimationController(
-        duration: const Duration(milliseconds: 150), vsync: overlay);
-  }
-
   TextSelection get _selection => value.selection;
 
   Animation<double> get _toolbarOpacity => _toolbarController.view;
@@ -99,7 +100,7 @@ class EditorTextSelectionOverlay {
     toolbar = OverlayEntry(builder: _buildToolbar);
     Overlay.of(context, rootOverlay: true, debugRequiredFor: debugRequiredFor)!
         .insert(toolbar!);
-    _toolbarController.forward(from: 0.0);
+    _toolbarController.forward(from: 0);
   }
 
   Widget _buildHandle(
@@ -111,7 +112,7 @@ class EditorTextSelectionOverlay {
     return Visibility(
         visible: handlesVisible,
         child: _TextSelectionHandleOverlay(
-          onSelectionHandleChanged: (TextSelection? newSelection) {
+          onSelectionHandleChanged: (newSelection) {
             _handleSelectionHandleChanged(newSelection, position);
           },
           onSelectionHandleTapped: onSelectionHandleTapped,
@@ -155,32 +156,32 @@ class EditorTextSelectionOverlay {
       default:
         throw 'Invalid position';
     }
-    selectionDelegate.textEditingValue =
+    selectionDelegate
-        value.copyWith(selection: newSelection, composing: TextRange.empty);
+      ..textEditingValue =
-    selectionDelegate.bringIntoView(textPosition);
+          value.copyWith(selection: newSelection, composing: TextRange.empty)
+      ..bringIntoView(textPosition);
   }
 
   Widget _buildToolbar(BuildContext context) {
-    List<TextSelectionPoint> endpoints =
+    final endpoints = renderObject!.getEndpointsForSelection(_selection);
-        renderObject!.getEndpointsForSelection(_selection);
 
-    Rect editingRegion = Rect.fromPoints(
+    final editingRegion = Rect.fromPoints(
       renderObject!.localToGlobal(Offset.zero),
       renderObject!.localToGlobal(renderObject!.size.bottomRight(Offset.zero)),
     );
 
-    double baseLineHeight = renderObject!.preferredLineHeight(_selection.base);
+    final baseLineHeight = renderObject!.preferredLineHeight(_selection.base);
-    double extentLineHeight =
+    final extentLineHeight =
         renderObject!.preferredLineHeight(_selection.extent);
-    double smallestLineHeight = math.min(baseLineHeight, extentLineHeight);
+    final smallestLineHeight = math.min(baseLineHeight, extentLineHeight);
-    bool isMultiline = endpoints.last.point.dy - endpoints.first.point.dy >
+    final isMultiline = endpoints.last.point.dy - endpoints.first.point.dy >
         smallestLineHeight / 2;
 
-    double midX = isMultiline
+    final midX = isMultiline
         ? editingRegion.width / 2
         : (endpoints.first.point.dx + endpoints.last.point.dx) / 2;
 
-    Offset midpoint = Offset(
+    final midpoint = Offset(
       midX,
       endpoints[0].point.dy - baseLineHeight,
     );
@@ -232,10 +233,10 @@ class EditorTextSelectionOverlay {
     assert(_handles == null);
     _handles = <OverlayEntry>[
       OverlayEntry(
-          builder: (BuildContext context) =>
+          builder: (context) =>
               _buildHandle(context, _TextSelectionHandlePosition.START)),
       OverlayEntry(
-          builder: (BuildContext context) =>
+          builder: (context) =>
               _buildHandle(context, _TextSelectionHandlePosition.END)),
     ];
 
@@ -326,14 +327,14 @@ class _TextSelectionHandleOverlayState
   void _handleDragStart(DragStartDetails details) {}
 
   void _handleDragUpdate(DragUpdateDetails details) {
-    TextPosition position =
+    final position =
         widget.renderObject!.getPositionForOffset(details.globalPosition);
     if (widget.selection.isCollapsed) {
       widget.onSelectionHandleChanged(TextSelection.fromPosition(position));
       return;
     }
 
-    bool isNormalized =
+    final isNormalized =
         widget.selection.extentOffset >= widget.selection.baseOffset;
     TextSelection? newSelection;
     switch (widget.position) {
@@ -389,27 +390,26 @@ class _TextSelectionHandleOverlayState
         break;
     }
 
-    TextPosition textPosition =
+    final textPosition = widget.position == _TextSelectionHandlePosition.START
-        widget.position == _TextSelectionHandlePosition.START
+        ? widget.selection.base
-            ? widget.selection.base
+        : widget.selection.extent;
-            : widget.selection.extent;
+    final lineHeight = widget.renderObject!.preferredLineHeight(textPosition);
-    double lineHeight = widget.renderObject!.preferredLineHeight(textPosition);
+    final handleAnchor =
-    Offset handleAnchor =
         widget.selectionControls.getHandleAnchor(type!, lineHeight);
-    Size handleSize = widget.selectionControls.getHandleSize(lineHeight);
+    final handleSize = widget.selectionControls.getHandleSize(lineHeight);
 
-    Rect handleRect = Rect.fromLTWH(
+    final handleRect = Rect.fromLTWH(
       -handleAnchor.dx,
       -handleAnchor.dy,
       handleSize.width,
       handleSize.height,
     );
 
-    Rect interactiveRect = handleRect.expandToInclude(
+    final interactiveRect = handleRect.expandToInclude(
       Rect.fromCircle(
           center: handleRect.center, radius: kMinInteractiveDimension / 2),
     );
-    RelativeRect padding = RelativeRect.fromLTRB(
+    final padding = RelativeRect.fromLTRB(
       math.max((interactiveRect.width - handleRect.width) / 2, 0),
       math.max((interactiveRect.height - handleRect.height) / 2, 0),
       math.max((interactiveRect.width - handleRect.width) / 2, 0),
@@ -657,13 +657,12 @@ class _EditorTextSelectionGestureDetectorState
 
   @override
   Widget build(BuildContext context) {
-    final Map<Type, GestureRecognizerFactory> gestures =
+    final gestures = <Type, GestureRecognizerFactory>{};
-        <Type, GestureRecognizerFactory>{};
 
     gestures[TapGestureRecognizer] =
         GestureRecognizerFactoryWithHandlers<TapGestureRecognizer>(
       () => TapGestureRecognizer(debugOwner: this),
-      (TapGestureRecognizer instance) {
+      (instance) {
         instance
           ..onTapDown = _handleTapDown
           ..onTapUp = _handleTapUp
@@ -678,7 +677,7 @@ class _EditorTextSelectionGestureDetectorState
           GestureRecognizerFactoryWithHandlers<LongPressGestureRecognizer>(
         () => LongPressGestureRecognizer(
             debugOwner: this, kind: PointerDeviceKind.touch),
-        (LongPressGestureRecognizer instance) {
+        (instance) {
           instance
             ..onLongPressStart = _handleLongPressStart
             ..onLongPressMoveUpdate = _handleLongPressMoveUpdate
@@ -694,7 +693,7 @@ class _EditorTextSelectionGestureDetectorState
           GestureRecognizerFactoryWithHandlers<HorizontalDragGestureRecognizer>(
         () => HorizontalDragGestureRecognizer(
             debugOwner: this, kind: PointerDeviceKind.mouse),
-        (HorizontalDragGestureRecognizer instance) {
+        (instance) {
           instance
             ..dragStartBehavior = DragStartBehavior.down
             ..onStart = _handleDragStart
@@ -708,7 +707,7 @@ class _EditorTextSelectionGestureDetectorState
       gestures[ForcePressGestureRecognizer] =
           GestureRecognizerFactoryWithHandlers<ForcePressGestureRecognizer>(
         () => ForcePressGestureRecognizer(debugOwner: this),
-        (ForcePressGestureRecognizer instance) {
+        (instance) {
           instance
             ..onStart =
                 widget.onForcePressStart != null ? _forcePressStarted : null

lib/widgets/toolbar.dart

@@ -5,31 +5,31 @@ import 'package:filesystem_picker/filesystem_picker.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_colorpicker/flutter_colorpicker.dart';
-import 'package:flutter_quill/models/documents/attribute.dart';
-import 'package:flutter_quill/models/documents/nodes/embed.dart';
-import 'package:flutter_quill/models/documents/style.dart';
-import 'package:flutter_quill/utils/color.dart';
 import 'package:image_picker/image_picker.dart';
 import 'package:path_provider/path_provider.dart';
 
+import '../models/documents/attribute.dart';
+import '../models/documents/nodes/embed.dart';
+import '../models/documents/style.dart';
+import '../utils/color.dart';
 import 'controller.dart';
 
-double iconSize = 18.0;
+double iconSize = 18;
 double kToolbarHeight = iconSize * 2;
 
 typedef OnImagePickCallback = Future<String> Function(File file);
 typedef ImagePickImpl = Future<String> Function(ImageSource source);
 
 class InsertEmbedButton extends StatelessWidget {
-  final QuillController controller;
-  final IconData icon;
-
   const InsertEmbedButton({
     required this.controller,
     required this.icon,
     Key? key,
   }) : super(key: key);
 
+  final QuillController controller;
+  final IconData icon;
+
   @override
   Widget build(BuildContext context) {
     return QuillIconButton(
@@ -52,15 +52,15 @@ class InsertEmbedButton extends StatelessWidget {
 }
 
 class LinkStyleButton extends StatefulWidget {
-  final QuillController controller;
-  final IconData? icon;
-
   const LinkStyleButton({
     required this.controller,
     this.icon,
     Key? key,
   }) : super(key: key);
 
+  final QuillController controller;
+  final IconData? icon;
+
   @override
   _LinkStyleButtonState createState() => _LinkStyleButtonState();
 }
@@ -174,14 +174,6 @@ typedef ToggleStyleButtonBuilder = Widget Function(
 );
 
 class ToggleStyleButton extends StatefulWidget {
-  final Attribute attribute;
-
-  final IconData icon;
-
-  final QuillController controller;
-
-  final ToggleStyleButtonBuilder childBuilder;
-
   const ToggleStyleButton({
     required this.attribute,
     required this.icon,
@@ -190,6 +182,14 @@ class ToggleStyleButton extends StatefulWidget {
     Key? key,
   }) : super(key: key);
 
+  final Attribute attribute;
+
+  final IconData icon;
+
+  final QuillController controller;
+
+  final ToggleStyleButtonBuilder childBuilder;
+
   @override
   _ToggleStyleButtonState createState() => _ToggleStyleButtonState();
 }
@@ -215,7 +215,7 @@ class _ToggleStyleButtonState extends State<ToggleStyleButton> {
 
   bool _getIsToggled(Map<String, Attribute> attrs) {
     if (widget.attribute.key == Attribute.list.key) {
-      Attribute? attribute = attrs[widget.attribute.key];
+      final attribute = attrs[widget.attribute.key];
       if (attribute == null) {
         return false;
       }
@@ -258,14 +258,6 @@ class _ToggleStyleButtonState extends State<ToggleStyleButton> {
 }
 
 class ToggleCheckListButton extends StatefulWidget {
-  final IconData icon;
-
-  final QuillController controller;
-
-  final ToggleStyleButtonBuilder childBuilder;
-
-  final Attribute attribute;
-
   const ToggleCheckListButton({
     required this.icon,
     required this.controller,
@@ -274,6 +266,14 @@ class ToggleCheckListButton extends StatefulWidget {
     Key? key,
   }) : super(key: key);
 
+  final IconData icon;
+
+  final QuillController controller;
+
+  final ToggleStyleButtonBuilder childBuilder;
+
+  final Attribute attribute;
+
   @override
   _ToggleCheckListButtonState createState() => _ToggleCheckListButtonState();
 }
@@ -299,7 +299,7 @@ class _ToggleCheckListButtonState extends State<ToggleCheckListButton> {
 
   bool _getIsToggled(Map<String, Attribute> attrs) {
     if (widget.attribute.key == Attribute.list.key) {
-      Attribute? attribute = attrs[widget.attribute.key];
+      final attribute = attrs[widget.attribute.key];
       if (attribute == null) {
         return false;
       }
@@ -369,11 +369,11 @@ Widget defaultToggleStyleButtonBuilder(
 }
 
 class SelectHeaderStyleButton extends StatefulWidget {
-  final QuillController controller;
-
   const SelectHeaderStyleButton({required this.controller, Key? key})
       : super(key: key);
 
+  final QuillController controller;
+
   @override
   _SelectHeaderStyleButtonState createState() =>
       _SelectHeaderStyleButtonState();
@@ -430,20 +430,20 @@ class _SelectHeaderStyleButtonState extends State<SelectHeaderStyleButton> {
 
 Widget _selectHeadingStyleButtonBuilder(BuildContext context, Attribute? value,
     ValueChanged<Attribute?> onSelected) {
-  final Map<Attribute, String> _valueToText = {
+  final _valueToText = <Attribute, String>{
     Attribute.header: 'N',
     Attribute.h1: 'H1',
     Attribute.h2: 'H2',
     Attribute.h3: 'H3',
   };
 
-  List<Attribute> _valueAttribute = [
+  final _valueAttribute = <Attribute>[
     Attribute.header,
     Attribute.h1,
     Attribute.h2,
     Attribute.h3
   ];
-  List<String> _valueString = ['N', 'H1', 'H2', 'H3'];
+  final _valueString = <String>['N', 'H1', 'H2', 'H3'];
 
   final theme = Theme.of(context);
   final style = TextStyle(
@@ -464,7 +464,7 @@ Widget _selectHeadingStyleButtonBuilder(BuildContext context, Attribute? value,
           child: RawMaterialButton(
             hoverElevation: 0,
             highlightElevation: 0,
-            elevation: 0.0,
+            elevation: 0,
             visualDensity: VisualDensity.compact,
             shape:
                 RoundedRectangleBorder(borderRadius: BorderRadius.circular(2)),
@@ -490,6 +490,15 @@ Widget _selectHeadingStyleButtonBuilder(BuildContext context, Attribute? value,
 }
 
 class ImageButton extends StatefulWidget {
+  const ImageButton({
+    required this.icon,
+    required this.controller,
+    required this.imageSource,
+    this.onImagePickCallback,
+    this.imagePickImpl,
+    Key? key,
+  }) : super(key: key);
+
   final IconData icon;
 
   final QuillController controller;
@@ -500,15 +509,6 @@ class ImageButton extends StatefulWidget {
 
   final ImageSource imageSource;
 
-  const ImageButton({
-    required this.icon,
-    required this.controller,
-    required this.imageSource,
-    this.onImagePickCallback,
-    this.imagePickImpl,
-    Key? key,
-  }) : super(key: key);
-
   @override
   _ImageButtonState createState() => _ImageButtonState();
 }
@@ -520,10 +520,10 @@ class _ImageButtonState extends State<ImageButton> {
   final FileType _pickingType = FileType.any;
 
   Future<String?> _pickImage(ImageSource source) async {
-    final PickedFile? pickedFile = await _picker.getImage(source: source);
+    final pickedFile = await _picker.getImage(source: source);
     if (pickedFile == null) return null;
 
-    final File file = File(pickedFile.path);
+    final file = File(pickedFile.path);
 
     return widget.onImagePickCallback!(file);
   }
@@ -536,11 +536,11 @@ class _ImageButtonState extends State<ImageButton> {
           : null,
     ))
         ?.files;
-    var _fileName =
+    final _fileName =
         _paths != null ? _paths!.map((e) => e.name).toString() : '...';
 
     if (_paths != null) {
-      File file = File(_fileName);
+      final file = File(_fileName);
       // We simply return the absolute path to selected file.
       return widget.onImagePickCallback!(file);
     } else {
@@ -550,7 +550,7 @@ class _ImageButtonState extends State<ImageButton> {
   }
 
   Future<String> _pickImageDesktop() async {
-    var filePath = await FilesystemPicker.open(
+    final filePath = await FilesystemPicker.open(
       context: context,
       rootDirectory: await getApplicationDocumentsDirectory(),
       fsType: FilesystemType.file,
@@ -558,7 +558,7 @@ class _ImageButtonState extends State<ImageButton> {
     );
     if (filePath != null && filePath.isEmpty) return '';
 
-    final File file = File(filePath!);
+    final file = File(filePath!);
     return widget.onImagePickCallback!(file);
   }
 
@@ -602,10 +602,6 @@ class _ImageButtonState extends State<ImageButton> {
 /// When pressed, this button displays overlay toolbar with
 /// buttons for each color.
 class ColorButton extends StatefulWidget {
-  final IconData icon;
-  final bool background;
-  final QuillController controller;
-
   const ColorButton({
     required this.icon,
     required this.controller,
@@ -613,6 +609,10 @@ class ColorButton extends StatefulWidget {
     Key? key,
   }) : super(key: key);
 
+  final IconData icon;
+  final bool background;
+  final QuillController controller;
+
   @override
   _ColorButtonState createState() => _ColorButtonState();
 }
@@ -683,19 +683,19 @@ class _ColorButtonState extends State<ColorButton> {
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
-    Color? iconColor = _isToggledColor && !widget.background && !_isWhite
+    final iconColor = _isToggledColor && !widget.background && !_isWhite
         ? stringToColor(_selectionStyle.attributes['color']!.value)
         : theme.iconTheme.color;
 
-    var iconColorBackground =
+    final iconColorBackground =
         _isToggledBackground && widget.background && !_isWhitebackground
             ? stringToColor(_selectionStyle.attributes['background']!.value)
             : theme.iconTheme.color;
 
-    Color fillColor = _isToggledColor && !widget.background && _isWhite
+    final fillColor = _isToggledColor && !widget.background && _isWhite
         ? stringToColor('#ffffff')
         : theme.canvasColor;
-    Color fillColorBackground =
+    final fillColorBackground =
         _isToggledBackground && widget.background && _isWhitebackground
             ? stringToColor('#ffffff')
             : theme.canvasColor;
@@ -713,7 +713,7 @@ class _ColorButtonState extends State<ColorButton> {
   }
 
   void _changeColor(Color color) {
-    String hex = color.value.toRadixString(16);
+    var hex = color.value.toRadixString(16);
     if (hex.startsWith('ff')) {
       hex = hex.substring(2);
     }
@@ -740,10 +740,6 @@ class _ColorButtonState extends State<ColorButton> {
 }
 
 class HistoryButton extends StatefulWidget {
-  final IconData icon;
-  final bool undo;
-  final QuillController controller;
-
   const HistoryButton({
     required this.icon,
     required this.controller,
@@ -751,6 +747,10 @@ class HistoryButton extends StatefulWidget {
     Key? key,
   }) : super(key: key);
 
+  final IconData icon;
+  final bool undo;
+  final QuillController controller;
+
   @override
   _HistoryButtonState createState() => _HistoryButtonState();
 }
@@ -812,10 +812,6 @@ class _HistoryButtonState extends State<HistoryButton> {
 }
 
 class IndentButton extends StatefulWidget {
-  final IconData icon;
-  final QuillController controller;
-  final bool isIncrease;
-
   const IndentButton({
     required this.icon,
     required this.controller,
@@ -823,6 +819,10 @@ class IndentButton extends StatefulWidget {
     Key? key,
   }) : super(key: key);
 
+  final IconData icon;
+  final QuillController controller;
+  final bool isIncrease;
+
   @override
   _IndentButtonState createState() => _IndentButtonState();
 }
@@ -867,16 +867,16 @@ class _IndentButtonState extends State<IndentButton> {
 }
 
 class ClearFormatButton extends StatefulWidget {
-  final IconData icon;
-
-  final QuillController controller;
-
   const ClearFormatButton({
     required this.icon,
     required this.controller,
     Key? key,
   }) : super(key: key);
 
+  final IconData icon;
+
+  final QuillController controller;
+
   @override
   _ClearFormatButtonState createState() => _ClearFormatButtonState();
 }
@@ -894,7 +894,7 @@ class _ClearFormatButtonState extends State<ClearFormatButton> {
         icon: Icon(widget.icon, size: iconSize, color: iconColor),
         fillColor: fillColor,
         onPressed: () {
-          for (Attribute k
+          for (final k
               in widget.controller.getSelectionStyle().attributes.values) {
             widget.controller.formatSelection(Attribute.clone(k, null));
           }
@@ -903,8 +903,6 @@ class _ClearFormatButtonState extends State<ClearFormatButton> {
 }
 
 class QuillToolbar extends StatefulWidget implements PreferredSizeWidget {
-  final List<Widget> children;
-
   const QuillToolbar({required this.children, Key? key}) : super(key: key);
 
   factory QuillToolbar.basic({
@@ -1117,6 +1115,8 @@ class QuillToolbar extends StatefulWidget implements PreferredSizeWidget {
     ]);
   }
 
+  final List<Widget> children;
+
   @override
   _QuillToolbarState createState() => _QuillToolbarState();
 
@@ -1148,13 +1148,6 @@ class _QuillToolbarState extends State<QuillToolbar> {
 }
 
 class QuillIconButton extends StatelessWidget {
-  final VoidCallback? onPressed;
-  final Widget? icon;
-  final double size;
-  final Color? fillColor;
-  final double hoverElevation;
-  final double highlightElevation;
-
   const QuillIconButton({
     required this.onPressed,
     this.icon,
@@ -1165,6 +1158,13 @@ class QuillIconButton extends StatelessWidget {
     Key? key,
   }) : super(key: key);
 
+  final VoidCallback? onPressed;
+  final Widget? icon;
+  final double size;
+  final Color? fillColor;
+  final double hoverElevation;
+  final double highlightElevation;
+
   @override
   Widget build(BuildContext context) {
     return ConstrainedBox(
@@ -1184,15 +1184,6 @@ class QuillIconButton extends StatelessWidget {
 }
 
 class QuillDropdownButton<T> extends StatefulWidget {
-  final double height;
-  final Color? fillColor;
-  final double hoverElevation;
-  final double highlightElevation;
-  final Widget child;
-  final T initialValue;
-  final List<PopupMenuEntry<T>> items;
-  final ValueChanged<T> onSelected;
-
   const QuillDropdownButton({
     required this.child,
     required this.initialValue,
@@ -1205,6 +1196,15 @@ class QuillDropdownButton<T> extends StatefulWidget {
     Key? key,
   }) : super(key: key);
 
+  final double height;
+  final Color? fillColor;
+  final double hoverElevation;
+  final double highlightElevation;
+  final Widget child;
+  final T initialValue;
+  final List<PopupMenuEntry<T>> items;
+  final ValueChanged<T> onSelected;
+
   @override
   _QuillDropdownButtonState<T> createState() => _QuillDropdownButtonState<T>();
 }
@@ -1251,7 +1251,7 @@ class _QuillDropdownButtonState<T> extends State<QuillDropdownButton<T>> {
       // widget.shape ?? popupMenuTheme.shape,
       color: popupMenuTheme.color, // widget.color ?? popupMenuTheme.color,
       // captureInheritedThemes: widget.captureInheritedThemes,
-    ).then((T? newValue) {
+    ).then((newValue) {
       if (!mounted) return null;
       if (newValue == null) {
         // if (widget.onCanceled != null) widget.onCanceled();
@@ -1265,7 +1265,7 @@ class _QuillDropdownButtonState<T> extends State<QuillDropdownButton<T>> {
     return ConstrainedBox(
       constraints: const BoxConstraints.tightFor(width: 110),
       child: Padding(
-        padding: const EdgeInsets.symmetric(horizontal: 8.0),
+        padding: const EdgeInsets.symmetric(horizontal: 8),
         child: Row(
           children: [
             widget.child,

pubspec.yaml

@@ -1,6 +1,6 @@
 name: flutter_quill
 description: A rich text editor supporting mobile and web (Demo App @ bulletjournal.us)
-version: 1.1.7
+version: 1.1.8
 #author: bulletjournal
 homepage: https://bulletjournal.us/home/index.html
 repository: https://github.com/singerdmx/flutter-quill