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

void main() {
  runApp(
    MaterialApp(
        debugShowCheckedModeBanner: false,
        home: SomaticCursorPage()),
  );
}

class SomaticCursorPage extends StatefulWidget {
  @override
  _SomaticCursorPageState createState() => _SomaticCursorPageState();
}

class _SomaticCursorPageState extends State<SomaticCursorPage> {
  static const _eventChannel = EventChannel("sensor");

  double x = 0;
  double y = 0;
  double offsetX = 0;
  double offsetY = 0;

  @override
  void initState() {
    super.initState();
    _eventChannel.receiveBroadcastStream().listen((data) {
      if (data is List) {
        setState(() {
          x = (data[0] * 20 * 100) - offsetX;
          y = (data[1] * 30 * 100) - offsetY;
        });
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white,
      body: Stack(
        children: [
          Center(
            child: Transform.translate(
              offset: Offset(x, y),
              child: Container(
                width: 50,
                height: 50,
                decoration: BoxDecoration(
                  color: Colors.blue,
                  shape: BoxShape.circle,
                ),
              ),
            ),
          ),
          Align(
            alignment: Alignment.bottomCenter,
            child: Padding(
              padding: const EdgeInsets.all(40.0),
              child: IconButton(
                icon: Icon(Icons.refresh, size: 40),
                onPressed: () {
                  setState(() {
                    offsetX += x;
                    offsetY += y;
                  });
                },
              ),
            ),
          ),
        ],
      ),
    );
  }
}