ha_client/lib/main.dart

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

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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Hass Client',
      theme: new ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: new MyHomePage(title: 'Hass main'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  List entities = [];

  void _getHassStates() async {
    String dataURL = "https://homeassistant:8123/api/states";
    http.Response response = await http.get(dataURL, headers: {"X-HA-Access": "password"});
    setState(() {
      entities = json.decode(response.body);
    });
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
    });
  }

  Widget parseEntity(int i) {
    return Card(
      child: new Column(
        mainAxisSize: MainAxisSize.min,
        children: <Widget>[
          new ListTile(
            leading: const Icon(Icons.device_hub),
            title: Text("${entities[i]["entity_id"]}"),
            subtitle: Text("${entities[i]["state"]}"),
          ),
        ],
      ),
    );



    return Padding(
        padding: EdgeInsets.all(10.0),
        child: Text("Row ${entities[i]["entity_id"]}")
    );
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return new Scaffold(
      appBar: new AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: new Text(widget.title),
      ),
      body: ListView.builder(
          itemCount: entities.length,
          itemBuilder: (BuildContext context, int position) {
            return parseEntity(position);
          }),
      floatingActionButton: new FloatingActionButton(
        onPressed: _getHassStates,
        tooltip: 'Increment',
        child: new Icon(Icons.refresh),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}