Feat: Spellchecker for Flutter Quill (#2118)

* Feat: added spellchecker service

* Partial implementation of spell_checker

* Feat: now spell-checking works in real-time

* Doc: more documentation about the new service

* Update simple_spell_checker to last version

* Fix: spellcheck highlight text into code-block and when readOnly is true

* Fix: last version dependency has weird behaviors with accents

* dart formatting

---------

Co-authored-by: CatHood0 <santiagowmar@gmail.com>

lib/flutter_quill.dart

@@ -24,6 +24,9 @@ export 'src/editor/raw_editor/config/raw_editor_configurations.dart';
 export 'src/editor/raw_editor/quill_single_child_scroll_view.dart';
 export 'src/editor/raw_editor/raw_editor.dart';
 export 'src/editor/raw_editor/raw_editor_state.dart';
+export 'src/editor/spellchecker/simple_spellchecker_impl.dart';
+export 'src/editor/spellchecker/spellchecker_service.dart';
+export 'src/editor/spellchecker/spellchecker_service_provider.dart';
 export 'src/editor/style_widgets/style_widgets.dart';
 export 'src/editor/widgets/cursor.dart';
 export 'src/editor/widgets/default_styles.dart';

lib/src/editor/spellchecker/default_spellchecker_service.dart

@@ -0,0 +1,20 @@
+import 'package:flutter/gestures.dart' show LongPressGestureRecognizer;
+import 'package:flutter/material.dart' show TextSpan;
+import 'spellchecker_service.dart' show SpellcheckerService;
+
+/// A default implementation of the [SpellcheckerService]
+/// that always will return null since Spell checking
+/// is not a standard feature
+class DefaultSpellcheckerService extends SpellcheckerService {
+  DefaultSpellcheckerService() : super(language: 'en');
+
+  @override
+  void dispose({bool onlyPartial = false}) {}
+
+  @override
+  List<TextSpan>? fetchSpellchecker(String text,
+      {LongPressGestureRecognizer Function(String p1)?
+          customLongPressRecognizerOnWrongSpan}) {
+    return null;
+  }
+}

lib/src/editor/spellchecker/simple_spellchecker_impl.dart

@@ -0,0 +1,42 @@
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+import 'package:simple_spell_checker/simple_spell_checker.dart';
+
+import 'spellchecker_service.dart';
+
+/// SimpleSpellCheckerImpl is a simple spell checker for get
+/// all words divide on different objects if them are wrong or not
+class SimpleSpellCheckerImpl extends SpellcheckerService {
+  SimpleSpellCheckerImpl({required super.language})
+      : checker = SimpleSpellChecker(
+          language: language,
+          safeDictionaryLoad: true,
+        );
+
+  /// [SimpleSpellChecker] comes from the package [simple_spell_checker]
+  /// that give us all necessary methods for get our spans with highlighting
+  /// where needed
+  final SimpleSpellChecker checker;
+
+  @override
+  List<TextSpan>? fetchSpellchecker(
+    String text, {
+    LongPressGestureRecognizer Function(String word)?
+        customLongPressRecognizerOnWrongSpan,
+  }) {
+    return checker.check(
+      text,
+      customLongPressRecognizerOnWrongSpan:
+          customLongPressRecognizerOnWrongSpan,
+    );
+  }
+
+  @override
+  void dispose({bool onlyPartial = false}) {
+    if (onlyPartial) {
+      checker.disposeControllers();
+      return;
+    }
+    checker.dispose(closeDirectionary: true);
+  }
+}

lib/src/editor/spellchecker/spellchecker_service.dart

@@ -0,0 +1,24 @@
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+
+/// A representation a custom SpellCheckService.
+abstract class SpellcheckerService {
+  SpellcheckerService({required this.language});
+
+  final String language;
+
+  /// dispose all the resources used for SpellcheckerService
+  ///
+  /// if [onlyPartial] is true just dispose a part of the SpellcheckerService
+  /// (this comes from the implementation)
+  ///
+  /// if [onlyPartial] is false dispose all resources
+  void dispose({bool onlyPartial = false});
+
+  /// Facilitates a spell check request.
+  ///
+  /// Returns a [List<TextSpan>] with all misspelled words divide from the right words.
+  List<TextSpan>? fetchSpellchecker(String text,
+      {LongPressGestureRecognizer Function(String)?
+          customLongPressRecognizerOnWrongSpan});
+}

lib/src/editor/spellchecker/spellchecker_service_provider.dart

@@ -0,0 +1,19 @@
+import 'package:flutter/foundation.dart' show immutable;
+import 'default_spellchecker_service.dart';
+import 'spellchecker_service.dart';
+
+@immutable
+class SpellcheckerServiceProvider {
+  const SpellcheckerServiceProvider._();
+  static SpellcheckerService _instance = DefaultSpellcheckerService();
+
+  static SpellcheckerService get instance => _instance;
+
+  static void setInstance(SpellcheckerService service) {
+    _instance = service;
+  }
+
+  static void setInstanceToDefault() {
+    _instance = DefaultSpellcheckerService();
+  }
+}

lib/src/editor/widgets/text/text_line.dart

@@ -391,10 +391,8 @@ class _TextLineState extends State<TextLine> {
     final nodeStyle = textNode.style;
     final isLink = nodeStyle.containsKey(Attribute.link.key) &&
         nodeStyle.attributes[Attribute.link.key]!.value != null;
-
     final style =
         _getInlineTextStyle(nodeStyle, defaultStyles, lineStyle, isLink);
-
     if (widget.controller.configurations.requireScriptFontFeatures == false &&
         textNode.value.isNotEmpty) {
       if (nodeStyle.containsKey(Attribute.script.key)) {
@@ -406,6 +404,21 @@ class _TextLineState extends State<TextLine> {
       }
     }
 
+    if (!isLink &&
+        !widget.readOnly &&
+        !widget.line.style.attributes.containsKey('code-block') &&
+        !kIsWeb) {
+      final service = SpellcheckerServiceProvider.instance;
+      final spellcheckedSpans = service.fetchSpellchecker(textNode.value);
+      if (spellcheckedSpans != null && spellcheckedSpans.isNotEmpty) {
+        return TextSpan(
+          children: spellcheckedSpans,
+          style: style,
+          mouseCursor: null,
+        );
+      }
+    }
+
     final recognizer = _getRecognizer(node, isLink);
     return TextSpan(
       text: textNode.value,

pubspec.yaml

@@ -45,6 +45,7 @@ dependencies:
   # Dart Packages
   intl: ^0.19.0
   dart_quill_delta: ^10.0.0
+  simple_spell_checker: ^1.0.6
   collection: ^1.17.0
   quiver: ^3.2.1
   equatable: ^2.0.5