MobileApp/lib/boxes/compass.dart

import 'dart:async';
import 'dart:ffi';
import 'dart:math';

import 'package:flutter/material.dart';
import 'package:flutter_svg/svg.dart';
import 'package:ju_rc_app/lib/boxes.dart';
import 'package:ju_rc_app/lib/sensors.dart';
import 'package:ju_rc_app/lib/serial.dart';

// c-structs
base class GnssLocData extends Struct {
  @Uint8()
  external int type;
  @Uint8()
  external int command;

  @Int32()
  external int X;
  @Int32()
  external int Y;
  @Int32()
  external int Z;
  @Int32()
  external int angle;
}
// end c-structs

class Compass extends JuBox {
  final bool small;
  const Compass(this.small, {super.key});

  @override
  // ignore: no_logic_in_create_state
  State<StatefulWidget> createState() => _CompassState(small);
}

class _CompassState extends State<Compass> {
  final bool small;

  _CompassState(this.small) : super();

  USerial serial = getSerial();
  Timer? timer;

  int _magX = 0, _magY = 0, _magZ = 0, _magAngle = 0;
  bool available = true;

  @override
  void initState() {
    super.initState();
    SensorReader.listen(serialListen);
    if (small) {
      timer = Timer.periodic(const Duration(milliseconds: 500), (_) async {
        if (available) serial.sprintln("<rfSystemSensor>2200", system: true);
      });
    }
  }

  @override
  void dispose() {
    SensorReader.removeListen(serialListen);
    timer?.cancel();
    super.dispose();
  }

  void serialListen(int type, int command, Pointer<ArrayCStruct> ptr) {
    if (type == 0x22 && command == 0xff) {
      setState(() {
        available = false;
      });
      return;
    }
    if (type != 0x22 || command != 0x00) return;
    var loc = ptr as Pointer<GnssLocData>;
    setState(() {
      _magX = loc.ref.X;
      _magY = loc.ref.Y;
      _magZ = loc.ref.Z;
      int newAngle = loc.ref.angle;
      if (newAngle - _magAngle > 200) newAngle -= 360;
      if (newAngle - _magAngle < -200) newAngle += 360;
      _magAngle = newAngle;
    });
  }

  @override
  Widget build(BuildContext context) => small
      ? GestureDetector(
          onTap: () {
            if (available) {
              Navigator.push(
                context,
                MaterialPageRoute(builder: (context) => const Compass(false)),
              );
            } else {
              available = true;
            }
          },
          child: buildLoc(context))
      : Scaffold(
          appBar: AppBar(
            backgroundColor: Theme.of(context).colorScheme.inversePrimary,
            title: const Text(
              "Compass",
              style: TextStyle(
                fontSize: 16,
              ),
            ),
            toolbarHeight: 40,
          ),
          body: Container(
              padding: const EdgeInsets.all(0.3 * 2 * 20),
              child: buildLoc(context)),
        );

  Widget buildLoc(BuildContext context) => !available
      ? const Center(
          child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              crossAxisAlignment: CrossAxisAlignment.center,
              children: [Text("Compass is not available!"), Icon(Icons.block)]))
      : Stack(
          children: [
            Center(child: SvgPicture.asset('assets/compass.svg')),
            Center(
                child: AnimatedRotation(
                    turns: _magAngle / 360.0,
                    duration: const Duration(milliseconds: 500),
                    alignment: Alignment.center, // Rotate around the center
                    child: SvgPicture.asset('assets/needle.svg'))),
            Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                    "x: ${(_magX * 8.0 / 32768.0 * 100.0).toStringAsFixed(2)}µT"),
                Text(
                    "y: ${(_magY * 8.0 / 32768.0 * 100.0).toStringAsFixed(2)}µT"),
                Text(
                    "z: ${(_magZ * 8.0 / 32768.0 * 100.0).toStringAsFixed(2)}µT"),
                if (!small)
                  Expanded(
                    child: Align(
                      alignment: Alignment.bottomLeft,
                      child: FilledButton(
                        child: const Icon(Icons.calculate),
                        onPressed: () {
                          showDialog<String>(
                            context: context,
                            builder: (BuildContext context) => AlertDialog(
                              title: const Text('Callibrate Compass'),
                              content: const Text(
                                  'When clicking okay the compass will be calibrated, \ncompletely blocking all radio communication for 10 sec. \nWhile calibrating rotate the sensor in ever direction.'),
                              actions: <Widget>[
                                TextButton(
                                  onPressed: () =>
                                      Navigator.pop(context, 'Cancel'),
                                  child: const Text('Cancel'),
                                ),
                                TextButton(
                                  onPressed: () {
                                    serial.sprintln("<rfSystemSensor>2201",
                                        system: true);
                                    Navigator.pop(context, 'OK');
                                  },
                                  child: const Text('OK'),
                                ),
                              ],
                            ),
                          );
                          //
                        },
                      ),
                    ),
                  ),
              ],
            ),
            Align(
              alignment: Alignment.topRight,
              child: Text(
                  "t: ${(sqrt(_magX * _magX + _magY * _magY + _magZ * _magZ) * 8.0 / 32768.0 * 100.0).toStringAsFixed(2)}µT"),
            )
          ],
        );
}