How to do it...

In order to add a menu to your desktop app, follow the next steps:

1. In your project, open the pubspec.yaml file and add the following dependency:

 menubar:
   git:
     url: git://github.com/google/flutter-desktop-embedding.git
     path: plugins/menubar

2. In the http_helper.dart file in the data folder, edit the getFlutterBooks method, so that it becomes a more generic getBooks method that takes a String as a parameter, and move the params declaration inside the method, as shown here:

class HttpHelper {
 final String authority = 'www.googleapis.com';
 final String path = '/books/v1/volumes';
 Future<List<Book>> getBooks(String query) async {
 Map<String, dynamic> params = {'q':query, 'maxResults': '40', };
 ...

3. At the top of the book_list_screen.dart file, add the menubar import:

 import 'package:menubar/menubar.dart';

4. Move the HttpHelper helper declaration to the top of the _BookListScreenState...