search query after typing in searchDelegate flutter

i made a search delegate class and everything doing good but i need to search the query after the user stop typing not after he uses enter .

i searched alot but only found a way using a normal search class ,but i need to make it work in search delegate class

my code is below

import 'package:MyCima/Screens/search_screen/search_tab_bar.dart';
import 'package:MyCima/constants.dart';
import 'package:flutter/material.dart';

class SearchClass extends SearchDelegate {
  @override
  String? get searchFieldLabel => ' ابحث فى ماى سيما';
  @override
  ThemeData appBarTheme(BuildContext context) {
    final ThemeData theme = Theme.of(context).copyWith(
      scaffoldBackgroundColor: BACKGROUND_COLOR,
      appBarTheme: const AppBarTheme(backgroundColor: PRIMARY,),
      hintColor: Colors.white,
      textTheme: const TextTheme(
        headline6: TextStyle(
          color: Colors.white,
          fontSize: 18.0,
        ),
      ),
    );
    return theme;
  }

  @override
  List<Widget>? buildActions(BuildContext context) {
    return null;
  }

  @override
  Widget? buildLeading(BuildContext context) {
    return IconButton(
      onPressed: () {
        close(context, null);
      },
      icon: const Padding(
        padding: EdgeInsets.all(8.0),
        child: Icon(Icons.arrow_back),
      ),
    );
  }

  @override
  Widget buildResults(BuildContext context) {
    String searchQuery = '' ;
    searchQuery = query ;
    return SearchTabBar(searchQuery);
  }

  @override
  Widget buildSuggestions(BuildContext context) {
    return const Text('');
  }

}