content: import 'package:flutter/material.dart';
  
  import 'package:recipes_app/ui/widgets/google_sign_in_button.dart';
  import 'package:recipes_app/state_widget.dart';
  
  class LoginScreen extends StatefulWidget {
    @override
    _LoginScreenState createState() => _LoginScreenState();
  }
  
  class _LoginScreenState extends State<LoginScreen> {
    @override
    Widget build(BuildContext context) {
      // Private methods within build method help us to
      // organize our code and recognize structure of widget
      // that we're building:
      BoxDecoration _buildBackground() {
        return BoxDecoration(
          image: DecorationImage(
            image: AssetImage("assets/brooke-lark-385507-unsplash.jpg"),
            fit: BoxFit.cover,
          ),
        );
      }
  
      Text _buildText() {
        return Text(
          'Recipes',
          style: Theme.of(context).textTheme.headline,
          textAlign: TextAlign.center,
        );
      }
  
      return Scaffold(
        body: Container(
          decoration: _buildBackground(),
          child: Center(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                _buildText(),
                SizedBox(height: 50.0),
                GoogleSignInButton(
                  // Passing function callback as constructor argument:
                  onPressed: () => StateWidget.of(context).signInWithGoogle(),
                ),
              ],
            ),
          ),
        ),
      );
    }
  }
  