Added dispose to the LanguageCheckService

This should fix the potential memory leaks from using the `Throttling` and `Debounce` classes.

lib/core/controllers/colored_text_editing_controller.dart

@@ -53,6 +53,12 @@ class ColoredTextEditingController extends TextEditingController {
  );
  }
 
+ @override
+ void dispose() {
+ languageCheckService.dispose();
+ super.dispose();
+ }
+
  /// Replaces mistake with given replacement
  void replaceMistake(Mistake mistake, String replacement) {
  text = text.replaceRange(mistake.offset, mistake.endOffset, replacement);

lib/domain/language_check_service.dart

@@ -7,4 +7,10 @@ abstract class LanguageCheckService {
 
  /// Returns found mistakes in the given [text].
  Future<List<Mistake>> findMistakes(String text);
+
+ /// Disposes resources of this [LanguageCheckService].
+ Future<void> dispose() async {
+ // does nothing by default, but implementations may need to use it
+ return;
+ }
 }

lib/implementations/debounce_lang_tool_service.dart

@@ -24,4 +24,11 @@ class DebounceLangToolService extends LanguageCheckService {
 
  return value ?? [];
  }
+
+ @override
+ Future<void> dispose() async {
+ await debouncing.close();
+
+ return baseService.dispose();
+ }
 }

lib/implementations/throttling_lang_tool_service.dart

@@ -21,4 +21,11 @@ class ThrottlingLangToolService extends LanguageCheckService {
  Future<List<Mistake>> findMistakes(String text) =>
  throttling.throttle(() => baseService.findMistakes(text))
  as Future<List<Mistake>>;
+
+ @override
+ Future<void> dispose() async {
+ await throttling.close();
+
+ return baseService.dispose();
+ }
 }