flutter_device_compass 1.0.0

A Flutter compass plugin using device sensors. Heading is 0-360 degrees (0 = north).

example/lib/main.dart

import 'dart:math' as math;

import 'package:flutter/material.dart';
import 'package:flutter_device_compass/flutter_device_compass.dart';
import 'package:permission_handler/permission_handler.dart';

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

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  bool _hasPermissions = false;
  CompassEvent? _lastRead;
  DateTime? _lastReadAt;

  @override
  void initState() {
    super.initState();
    _fetchPermissionStatus();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        backgroundColor: Colors.white,
        appBar: AppBar(
          title: const Text('Device Compass'),
        ),
        body: Builder(
          builder: (context) {
            if (_hasPermissions) {
              return Column(
                children: <Widget>[
                  _buildManualReader(),
                  Expanded(child: _buildCompass()),
                ],
              );
            } else {
              return _buildPermissionSheet();
            }
          },
        ),
      ),
    );
  }

  Widget _buildManualReader() {
    return Padding(
      padding: const EdgeInsets.all(16.0),
      child: Row(
        children: <Widget>[
          ElevatedButton(
            onPressed: () async {
              final CompassEvent tmp = await FlutterCompass.events!.first;
              setState(() {
                _lastRead = tmp;
                _lastReadAt = DateTime.now();
              });
            },
            child: const Text('Read Value'),
          ),
          Expanded(
            child: Padding(
              padding: const EdgeInsets.all(8.0),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: <Widget>[
                  Text(
                    '$_lastRead',
                    style: Theme.of(context).textTheme.bodySmall,
                  ),
                  Text(
                    '$_lastReadAt',
                    style: Theme.of(context).textTheme.bodySmall,
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildCompass() {
    return StreamBuilder<CompassEvent>(
      stream: FlutterCompass.events,
      builder: (context, snapshot) {
        if (snapshot.hasError) {
          return Text('Error reading heading: ${snapshot.error}');
        }

        if (snapshot.connectionState == ConnectionState.waiting) {
          return const Center(
            child: CircularProgressIndicator(),
          );
        }

        final double? direction = snapshot.data!.heading;

        if (direction == null) {
          return const Center(
            child: Text('Device does not have sensors!'),
          );
        }

        return Material(
          shape: const CircleBorder(),
          clipBehavior: Clip.antiAlias,
          elevation: 4.0,
          child: Container(
            padding: const EdgeInsets.all(16.0),
            alignment: Alignment.center,
            decoration: const BoxDecoration(
              shape: BoxShape.circle,
            ),
            child: Transform.rotate(
              angle: direction * (math.pi / 180) * -1,
              child: Image.asset('assets/compass.jpg'),
            ),
          ),
        );
      },
    );
  }

  Widget _buildPermissionSheet() {
    return Center(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: <Widget>[
          const Text('Location Permission Required'),
          ElevatedButton(
            onPressed: () {
              Permission.locationWhenInUse.request().then((_) {
                _fetchPermissionStatus();
              });
            },
            child: const Text('Request Permissions'),
          ),
          const SizedBox(height: 16),
          ElevatedButton(
            onPressed: () {
              openAppSettings();
            },
            child: const Text('Open App Settings'),
          ),
        ],
      ),
    );
  }

  void _fetchPermissionStatus() {
    Permission.locationWhenInUse.status.then((status) {
      if (mounted) {
        setState(() => _hasPermissions = status == PermissionStatus.granted);
      }
    });
  }
}