feat(sensors_plus): add magnetometer support

Added necessary Android, iOS, and web API for magnetometer sensor.

Adds new `MagnetometerEvent` class
(and fixes small typo in constructor of other `FooEvent` classes).

Adds new `Stream<MagnetometerEvent>` called `magnetometerEvents`.

Author: Zabadam

packages/sensors_plus/sensors_plus/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.1.0
+
+- Adds magnetometer support
+
 ## 1.0.2
 
 - Android: migrate to mavenCentral

packages/sensors_plus/sensors_plus/README.md

@@ -7,20 +7,22 @@
 <p class="center">
 <center><a href="https://flutter.dev/docs/development/packages-and-plugins/favorites" target="_blank" rel="noreferrer noopener"><img src="../../website/static/img/flutter-favorite-badge.png" width="100" alt="build"></a></center>
 </p>
-A Flutter plugin to access the accelerometer and gyroscope sensors.
+
+A Flutter plugin to access the accelerometer, gyroscope, and magnetometer
+sensors.
 
 ## Platform Support
 
-| Android | iOS | MacOS | Web | Linux | Windows |
-| :-----: | :-: | :---: | :-: | :---: | :----: |
-|   ✔️    | ✔️  |       | ✔️  |       |        |
+| Android |  iOS  | MacOS |  Web  | Linux | Windows |
+| :-----: | :---: | :---: | :---: | :---: | :-----: |
+|   ✔️   |   ✔️   |      |   ✔️  |       |         |
 
 ## Usage
 
 To use this plugin, add `sensors_plus` as a [dependency in your pubspec.yaml
 file](https://plus.fluttercommunity.dev/docs/overview).
 
-This will expose three classes of sensor events, through three different
+This will expose four classes of sensor events through four different
 streams.
 
 - `AccelerometerEvent`s describe the velocity of the device, including the
@@ -30,9 +32,12 @@ streams.
   include gravity. They can also be thought of as just the user's affect on the
   device.
 - `GyroscopeEvent`s describe the rotation of the device.
+- `MagnetometerEvent`s describe the ambient magnetic field surrounding the
+  device. A compass is an example usage of this data.
 
 Each of these is exposed through a `BroadcastStream`: `accelerometerEvents`,
-`userAccelerometerEvents`, and `gyroscopeEvents`, respectively.
+`userAccelerometerEvents`, `gyroscopeEvents`, and `magnetometerEvents`,
+respectively.
 
 ### Example
 
@@ -54,11 +59,20 @@ gyroscopeEvents.listen((GyroscopeEvent event) {
 });
 // [GyroscopeEvent (x: 0.0, y: 0.0, z: 0.0)]
 
+magnetometerEvents.listen((MagnetometerEvent event) {
+  print(event);
+});
+// [MagnetometerEvent (x: -23.6, y: 6.2, z: -34.9)]
+
 ```
 
 Also see the `example` subdirectory for an example application that uses the
 sensor data.
 
-Check out our documentation website to learn more. [Plus plugins documentation](https://plus.fluttercommunity.dev/docs/overview)
+Check out our website to learn more: [Plus Plugins documentation](https://plus.fluttercommunity.dev/docs/overview)
 
-**Important:** As of January 2021, the Flutter team is no longer accepting non-critical PRs for the original set of plugins in `flutter/plugins`, and instead they should be submitted in this project. [You can read more about this announcement here.](https://github.com/flutter/plugins/blob/master/CONTRIBUTING.md#important-note) as well as [in the Flutter 2 announcement blog post.](https://medium.com/flutter/whats-new-in-flutter-2-0-fe8e95ecc65)
+**Important:** As of January 2021, the Flutter team is no longer accepting
+non-critical PRs for the original set of plugins in `flutter/plugins`, and
+instead they should be submitted in this project.
+[You can read more about this announcement here](https://github.com/flutter/plugins/blob/master/CONTRIBUTING.md#important-note)
+as well as [in the Flutter 2 announcement blog post](https://medium.com/flutter/whats-new-in-flutter-2-0-fe8e95ecc65).

packages/sensors_plus/sensors_plus/android/src/main/java/dev/fluttercommunity/plus/sensors/SensorsPlugin.java

@@ -20,10 +20,13 @@ public class SensorsPlugin implements FlutterPlugin {
       "dev.fluttercommunity.plus/sensors/gyroscope";
   private static final String USER_ACCELEROMETER_CHANNEL_NAME =
       "dev.fluttercommunity.plus/sensors/user_accel";
+  private static final String MAGNETOMETER_CHANNEL_NAME =
+      "dev.fluttercommunity.plus/sensors/magnetometer";
 
   private EventChannel accelerometerChannel;
   private EventChannel userAccelChannel;
   private EventChannel gyroscopeChannel;
+  private EventChannel magnetometerChannel;
 
   /** Plugin registration. */
   public static void registerWith(Registrar registrar) {
@@ -63,11 +66,19 @@ private void setupEventChannels(Context context, BinaryMessenger messenger) {
             (SensorManager) context.getSystemService(context.SENSOR_SERVICE),
             Sensor.TYPE_GYROSCOPE);
     gyroscopeChannel.setStreamHandler(gyroScopeStreamHandler);
+
+    magnetometerChannel = new EventChannel(messenger, MAGNETOMETER_CHANNEL_NAME);
+    final StreamHandlerImpl magnetometerStreamHandler =
+        new StreamHandlerImpl(
+            (SensorManager) context.getSystemService(context.SENSOR_SERVICE),
+            Sensor.TYPE_MAGNETIC_FIELD);
+    magnetometerChannel.setStreamHandler(magnetometerStreamHandler);
   }
 
   private void teardownEventChannels() {
     accelerometerChannel.setStreamHandler(null);
     userAccelChannel.setStreamHandler(null);
     gyroscopeChannel.setStreamHandler(null);
+    magnetometerChannel.setStreamHandler(null);
   }
 }

packages/sensors_plus/sensors_plus/android/src/main/java/dev/fluttercommunity/plus/sensors/StreamHandlerImpl.java

@@ -24,7 +24,11 @@ class StreamHandlerImpl implements EventChannel.StreamHandler {
   @Override
   public void onListen(Object arguments, EventChannel.EventSink events) {
     sensorEventListener = createSensorEventListener(events);
-    sensorManager.registerListener(sensorEventListener, sensor, sensorManager.SENSOR_DELAY_NORMAL);
+    // TODO: Could allow developer to alter rate?
+    // sensorManager.registerListener(sensorEventListener, sensor, sensorManager.SENSOR_DELAY_FASTEST); // 0
+    // sensorManager.registerListener(sensorEventListener, sensor, sensorManager.SENSOR_DELAY_GAME); // 1
+    // sensorManager.registerListener(sensorEventListener, sensor, sensorManager.SENSOR_DELAY_UI); // 2
+    sensorManager.registerListener(sensorEventListener, sensor, sensorManager.SENSOR_DELAY_NORMAL); // 3
   }
 
   @Override

packages/sensors_plus/sensors_plus/example/android/gradle/wrapper/gradle-wrapper.properties

@@ -2,4 +2,5 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.2-all.zip
+# distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.4.1-all.zip

packages/sensors_plus/sensors_plus/example/lib/main.dart

@@ -44,6 +44,7 @@ class _MyHomePageState extends State<MyHomePage> {
   List<double>? _accelerometerValues;
   List<double>? _userAccelerometerValues;
   List<double>? _gyroscopeValues;
+  List<double>? _magnetometerValues;
   final _streamSubscriptions = <StreamSubscription<dynamic>>[];
 
   @override
@@ -55,6 +56,8 @@ class _MyHomePageState extends State<MyHomePage> {
     final userAccelerometer = _userAccelerometerValues
         ?.map((double v) => v.toStringAsFixed(1))
         .toList();
+    final magnetometer =
+        _magnetometerValues?.map((double v) => v.toStringAsFixed(1)).toList();
 
     return Scaffold(
       appBar: AppBar(
@@ -106,6 +109,15 @@ class _MyHomePageState extends State<MyHomePage> {
               ],
             ),
           ),
+          Padding(
+            padding: const EdgeInsets.all(16.0),
+            child: Row(
+              mainAxisAlignment: MainAxisAlignment.spaceBetween,
+              children: <Widget>[
+                Text('Magnetometer: $magnetometer'),
+              ],
+            ),
+          ),
         ],
       ),
     );
@@ -149,5 +161,14 @@ class _MyHomePageState extends State<MyHomePage> {
         },
       ),
     );
+    _streamSubscriptions.add(
+      magnetometerEvents.listen(
+        (MagnetometerEvent event) {
+          setState(() {
+            _magnetometerValues = <double>[event.x, event.y, event.z];
+          });
+        },
+      ),
+    );
   }
 }

packages/sensors_plus/sensors_plus/ios/Classes/FLTSensorsPlusPlugin.h

@@ -15,3 +15,6 @@
 
 @interface FLTGyroscopeStreamHandlerPlus : NSObject <FlutterStreamHandler>
 @end
+
+@interface FLTMagnetometerStreamHandlerPlus : NSObject <FlutterStreamHandler>
+@end

packages/sensors_plus/sensors_plus/ios/Classes/FLTSensorsPlusPlugin.m

@@ -28,6 +28,13 @@ + (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar>*)registrar {
       [FlutterEventChannel eventChannelWithName:@"dev.fluttercommunity.plus/sensors/gyroscope"
                                 binaryMessenger:[registrar messenger]];
   [gyroscopeChannel setStreamHandler:gyroscopeStreamHandler];
+
+  FLTMagnetometerStreamHandlerPlus* magnetometerStreamHandler =
+      [[FLTMagnetometerStreamHandlerPlus alloc] init];
+  FlutterEventChannel* magnetometerChannel =
+      [FlutterEventChannel eventChannelWithName:@"dev.fluttercommunity.plus/sensors/magnetometer"
+                                binaryMessenger:[registrar messenger]];
+  [magnetometerChannel setStreamHandler:magnetometerStreamHandler];
 }
 
 @end
@@ -113,3 +120,23 @@ - (FlutterError*)onCancelWithArguments:(id)arguments {
 }
 
 @end
+
+@implementation FLTMagnetometerStreamHandlerPlus
+
+- (FlutterError*)onListenWithArguments:(id)arguments eventSink:(FlutterEventSink)eventSink {
+  _initMotionManager();
+  [_motionManager
+      startMagnetometerUpdatesToQueue:[[NSOperationQueue alloc] init]
+                  withHandler:^(CMMagnetometerData* magData, NSError* error) {
+                    CMMagneticField magneticField = magData.magneticField;
+                    sendTriplet(magneticField.x, magneticField.y, magneticField.z, eventSink);
+                  }];
+  return nil;
+}
+
+- (FlutterError*)onCancelWithArguments:(id)arguments {
+  [_motionManager stopMagnetometerUpdates];
+  return nil;
+}
+
+@end

packages/sensors_plus/sensors_plus/ios/sensors_plus.podspec

@@ -3,21 +3,21 @@
 #
 Pod::Spec.new do |s|
   s.name             = 'sensors_plus'
-  s.version          = '0.0.1'
-  s.summary          = 'Flutter Sensors'
+  s.version          = '0.1.0'
+  s.summary          = 'Flutter Community: Sensors Plus'
   s.description      = <<-DESC
-A Flutter plugin to access the accelerometer and gyroscope sensors.
+Flutter plugin to access the accelerometer, gyroscope, and magnetometer sensors.
                        DESC
-  s.homepage         = 'https://github.com/flutter/plugins'
+  # Should update?
+  s.homepage         = 'https://github.com/fluttercommunity/plus_plugins'
   s.license          = { :type => 'BSD', :file => '../LICENSE' }
   s.author           = { 'Flutter Dev Team' => '[email protected]' }
-  s.source           = { :http => 'https://github.com/flutter/plugins/tree/main/packages/sensors' }
-  s.documentation_url = 'https://pub.dev/packages/sensors'
+  s.source           = { :http => 'https://github.com/fluttercommunity/plus_plugins/tree/main/packages/sensors_plus' }
+  s.documentation_url = 'https://pub.dev/documentation/sensors_plus'
   s.source_files = 'Classes/**/*'
   s.public_header_files = 'Classes/**/*.h'
   s.dependency 'Flutter'
-  
+
   s.platform = :ios, '8.0'
   s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES', 'VALID_ARCHS[sdk=iphonesimulator*]' => 'x86_64' }
 end
-

packages/sensors_plus/sensors_plus/lib/sensors_plus.dart

@@ -21,3 +21,8 @@ Stream<GyroscopeEvent> get gyroscopeEvents {
 Stream<UserAccelerometerEvent> get userAccelerometerEvents {
   return _sensors.userAccelerometerEvents;
 }
+
+/// A broadcast stream of events from the device magnetometer.
+Stream<MagnetometerEvent> get magnetometerEvents {
+  return _sensors.magnetometerEvents;
+}