How To Create Searchable Text Using Flutter Android

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Retrieve Text Input',
      home: SearchText(),
    );
  }
}

class SearchText extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.pink,
        title: Text("Searchable Text"),
        actions: <Widget>[
          IconButton(
              icon: Icon(Icons.search),
              onPressed: () {
                showSearch(
                  context: context,
                  delegate: DataSearch(),
                );
              })
        ],
      ),
      drawer: Drawer(),
    );
  }
}

class DataSearch extends SearchDelegate<String> {
  final mobile = ['MotoRola', 'Samsung', 'Lenovo', 'Apple', 'Redmi','Realmi','Oppo'];
  var recentMobiles = ['MotoRola'];

  @override
  List<Widget> buildActions(BuildContext context) {
    return [
      IconButton(
          icon: Icon(Icons.clear),
          onPressed: () {
            query = "";
          })
    ];
  }

  @override
  Widget buildLeading(BuildContext context) {
    return IconButton(
        icon: AnimatedIcon(
          icon: AnimatedIcons.menu_arrow,
          progress: transitionAnimation,
        ),
        onPressed: () {
          close(context, null);
        });
  }

  @override
  Widget buildResults(BuildContext context) {
    return Center(
      child: Container(
        width: 100,
        height: 100,
        child: Card(
          color: Colors.pink,
          child: Center(child: Text(query,style: TextStyle(color: Colors.white),)),
        ),
      ),
    );
  }

  @override
  Widget buildSuggestions(BuildContext context) {
    final suggestionList = query.isEmpty
        ? recentMobiles
          : mobiles.where((p) => p.startsWith(query)).toList();

    return ListView.builder(
      itemBuilder: (context, index) => ListTile(
        onTap: () {
          showResults(context);
        },
        leading: Icon(Icons.mobile_friendly),
        title: RichText(
          text: TextSpan(
            text: suggestionList[index].substring(0, query.length),
            style: TextStyle(
              color: Colors.black,
              fontWeight: FontWeight.bold,
            ),
            children: [
              TextSpan(
                text: suggestionList[index].substring(query.length),
              ),
            ],
          ),
        ),
      ),
      itemCount: suggestionList.length,
    );
  }
}