Type Head Example

data.dart

import 'dart:math';

class BackendService {
  static Future<List> getSuggestions(String query) async {
    await Future.delayed(Duration(seconds: 1));

    return List.generate(3, (index) {
      return {'name': query + index.toString(), 'price': Random().nextInt(100)};
    });
  }
}

main.dart

import 'package:flutter/material.dart';
import 'package:flutter_typeahead/flutter_typeahead.dart';

import 'data.dart';

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

class MyApp extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return _MyApp();
  }
}

class _MyApp extends State<MyApp> {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text("TypeHead App"),
        ),
        body: Container(
          child: Center(
            child: Padding(
              padding: const EdgeInsets.all(10.0),
              child: TypeAheadField(
                textFieldConfiguration: TextFieldConfiguration(
                  autofocus: true,
                  style: DefaultTextStyle.of(context)
                      .style
                      .copyWith(fontStyle: FontStyle.italic),
                  decoration: InputDecoration(
                      border: OutlineInputBorder(),
                      hintText: 'What are you looking for?'),
                ),
                suggestionsCallback: (pattern) async {
                  // Here you can call http call 
                  return await BackendService.getSuggestions(pattern);
                },
                itemBuilder: (context, suggestion) {
                  return ListTile(
                    leading: Icon(Icons.shopping_cart),
                    title: Text(suggestion['name']),
                    subtitle: Text('\$${suggestion['price']}'),
                  );
                },
                onSuggestionSelected: (suggestion) {
                  // This when someone click the items
                  print(suggestion);
                },
              ),
            ),
          ),
        ),
      ),
    );
  }
}

pubspec.yaml

name: typeheadapp
description: A new Flutter project.

# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# In Android, build-name is used as versionName while build-number used as versionCode.
# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
# In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
# Read more about iOS versioning at
# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
version: 1.0.0+1

environment:
  sdk: ">=2.1.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter

  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^0.1.2
  flutter_typeahead: ^1.7.0

dev_dependencies:
  flutter_test:
    sdk: flutter


# For information on the generic Dart part of this file, see the
# following page: https://dart.dev/tools/pub/pubspec

# The following section is specific to Flutter.
flutter:

  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true

  # To add assets to your application, add an assets section, like this:
  # assets:
  #  - images/a_dot_burr.jpeg
  #  - images/a_dot_ham.jpeg

  # An image asset can refer to one or more resolution-specific "variants", see
  # https://flutter.dev/assets-and-images/#resolution-aware.

  # For details regarding adding assets from package dependencies, see
  # https://flutter.dev/assets-and-images/#from-packages

  # To add custom fonts to your application, add a fonts section here,
  # in this "flutter" section. Each entry in this list should have a
  # "family" key with the font family name, and a "fonts" key with a
  # list giving the asset and other descriptors for the font. For
  # example:
  # fonts:
  #   - family: Schyler
  #     fonts:
  #       - asset: fonts/Schyler-Regular.ttf
  #       - asset: fonts/Schyler-Italic.ttf
  #         style: italic
  #   - family: Trajan Pro
  #     fonts:
  #       - asset: fonts/TrajanPro.ttf
  #       - asset: fonts/TrajanPro_Bold.ttf
  #         weight: 700
  #
  # For details regarding fonts from package dependencies,
  # see https://flutter.dev/custom-fonts/#from-packages