Merge pull request #5 from natsuk4ze/Add-CompassXException

Add CompassXException

README.md

@@ -50,18 +50,17 @@ Request permission to get true heading in Android. Not required on iOS.
 $ flutter pub add permission_handler
 ```
 Specify the permissions one or both of the following in *AndroidManifest.xml*.
-It can be copied from [exmaple](https://github.com/natsuk4ze/compassx/blob/main/example/android/app/src/main/AndroidManifest.xml).
+It can be copied from [example](https://github.com/natsuk4ze/compassx/blob/main/example/android/app/src/main/AndroidManifest.xml).
 ```xml
 <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
 <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
 ```
 - `ACCESS_COARSE_LOCATION`: Used when normal accuracy is required.
 - `ACCESS_FINE_LOCATION`: Used when the highest quality accuracy is required.
 
-Add code to request premissions.
+Add code to request permissions.
 ```dart
-if (!Platform.isAndroid) return;
-await Permission.location.request();
+if (Platform.isAndroid) await Permission.location.request();
 ```
 
 ## Precautions

android/src/main/java/studio/midoridesign/compassx/CompassxPlugin.java

@@ -77,6 +77,9 @@ public void onListen(Object arguments, EventChannel.EventSink events) {
         } else if (rotationVectorSensor != null) {
             sensorManager.registerListener(sensorEventListener, rotationVectorSensor,
                     SensorManager.SENSOR_DELAY_GAME);
+        } else {
+            events.error("SENSOR_NOT_FOUND", "No compass sensor found.", null);
+            events.endOfStream();
         }
     }
 

lib/src/compassx.dart

@@ -10,5 +10,8 @@ final class CompassX {
   const CompassX._();
 
   /// [CompassXEvent] stream for using the compass sensor.
+  ///
+  /// Throws [CompassXException] for older or excessively cheap Android devices 
+  /// that do not have a compass sensor.
   static Stream<CompassXEvent> get events => CompassXPlatform.events;
 }

lib/src/compassx_exception.dart

@@ -0,0 +1,51 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter/services.dart';
+
+@immutable
+final class CompassXException implements Exception {
+  const CompassXException._({
+    required this.type,
+    required this.platformException,
+    required this.stackTrace,
+  });
+
+  final CompassXExceptionType type;
+  final PlatformException platformException;
+  final StackTrace stackTrace;
+
+  factory CompassXException.fromPlatformException({
+    required PlatformException platformException,
+    required StackTrace stackTrace,
+  }) =>
+      CompassXException._(
+        type: CompassXExceptionType.values.firstWhere(
+          (type) => type.code == platformException.code,
+          orElse: () => CompassXExceptionType.unexpected,
+        ),
+        platformException: platformException,
+        stackTrace: stackTrace,
+      );
+
+  @override
+  String toString() => "[CompassXException/${type.code}]: ${type.message}";
+}
+
+enum CompassXExceptionType {
+  /// This is used for older or excessively cheap Android devices
+  /// that do not have a compass sensor.
+  sensorNotFound,
+
+  /// This is used when an unexpected error occurs.
+  /// See [PlatformException] for more information.
+  unexpected;
+
+  String get code => switch (this) {
+        sensorNotFound => 'SENSOR_NOT_FOUND',
+        unexpected => 'UNEXPECTED',
+      };
+
+  String get message => switch (this) {
+        sensorNotFound => 'Compass sensor not found.',
+        unexpected => 'An unexpected error has occurred.',
+      };
+}

lib/src/compassx_platform.dart

@@ -1,4 +1,5 @@
 import 'package:compassx/src/compassx_event.dart';
+import 'package:compassx/src/compassx_exception.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 
@@ -14,5 +15,12 @@ final class CompassXPlatform {
   static final _stream = _channel.receiveBroadcastStream();
 
   /// CompassXEvent stream for [CompassX].
-  static Stream<CompassXEvent> get events => _stream.map(CompassXEvent.fromMap);
+  static Stream<CompassXEvent> get events =>
+      _stream.map(CompassXEvent.fromMap).handleError(
+            (e, st) => throw CompassXException.fromPlatformException(
+              platformException: e,
+              stackTrace: st,
+            ),
+            test: (e) => e is PlatformException,
+          );
 }