Flutter super app with single file

flutter_super_app_with_single_file.dart

import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;

class HomeScreen extends StatefulWidget {
  @override
  _HomeScreenState createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  http.Client _client;
  Future<List<Profile>> _futureProfiles;

  @override
  void initState() {
    _client = http.Client();
    _futureProfiles = _getProfiles();
    super.initState();
  }

  Future<List<Profile>> _getProfiles() async {
    String url = "http://api.bengkelrobot.net:8001";
    final response = await _client.get("$url/profile");
    if (response == 200) {
      return profileFromJson(response.body);
    } else {
      throw Exception("failed get profiles");
    }
  }

  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: FutureBuilder(
        future: _futureProfiles,
        builder: (BuildContext context, AsyncSnapshot<List<Profile>> snapshot) {
          if (snapshot.hasError) {
            return Center(
              child: Text(
                  "Something wrong with message: ${snapshot.error.toString()}"),
            );
          } else if (snapshot.connectionState == ConnectionState.done) {
            List<Profile> profiles = snapshot.data;
            return _buildListView(profiles);
          } else {
            return Center(
              child: CircularProgressIndicator(),
            );
          }
        },
      ),
    );
  }

  Widget _buildListView(List<Profile> profiles) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 8.0, horizontal: 16.0),
      child: ListView.builder(
        itemBuilder: (context, index) {
          Profile profile = profiles[index];
          return Padding(
            padding: const EdgeInsets.only(top: 8.0),
            child: Card(
              child: Padding(
                padding: const EdgeInsets.all(16.0),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: <Widget>[
                    Text(
                      profile.name,
                      style: Theme.of(context).textTheme.title,
                    ),
                    Text(profile.email),
                    Text(profile.age.toString()),
                    Row(
                      mainAxisAlignment: MainAxisAlignment.end,
                      children: <Widget>[
                        FlatButton(
                          onPressed: () {
                            // TODO: do something in here
                          },
                          child: Text(
                            "Delete",
                            style: TextStyle(color: Colors.red),
                          ),
                        ),
                        FlatButton(
                          onPressed: () {
                            // TODO: do something in here
                          },
                          child: Text(
                            "Edit",
                            style: TextStyle(color: Colors.blue),
                          ),
                        ),
                      ],
                    ),
                  ],
                ),
              ),
            ),
          );
        },
        itemCount: profiles.length,
      ),
    );
  }
}

class Profile {
  int id;
  String name;
  String email;
  int age;

  Profile({this.id = 0, this.name, this.email, this.age});

  factory Profile.fromJson(Map<String, dynamic> map) {
    return Profile(
        id: map["id"], name: map["name"], email: map["email"], age: map["age"]);
  }

  Map<String, dynamic> toJson() {
    return {"id": id, "name": name, "email": email, "age": age};
  }

  @override
  String toString() {
    return 'Profile{id: $id, name: $name, email: $email, age: $age}';
  }
}

List<Profile> profileFromJson(String jsonData) {
  final data = json.decode(jsonData);
  return List<Profile>.from(data.map((item) => Profile.fromJson(item)));
}

String profileToJson(Profile data) {
  final jsonData = data.toJson();
  return json.encode(jsonData);
}