[federated_plugin_sample] modify the sample to expose battery API instead of geolocation API (#526)

experimental/federated_plugin/README.md

@@ -1,6 +1,6 @@
 # federated_plugin
 
-A Flutter plugin sample that shows how to implement a federated plugin to fetch the device location on different platforms.
+A Flutter plugin sample that shows how to implement a federated plugin to retrieve current battery level on different platforms.
 
 This sample is currently being built. Not all platforms and functionality are in place.
 

experimental/federated_plugin/federated_plugin/android/build.gradle

@@ -40,5 +40,4 @@ android {
 
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-    implementation 'com.google.android.gms:play-services-location:17.0.0'
 }

experimental/federated_plugin/federated_plugin/android/src/main/AndroidManifest.xml

@@ -1,5 +1,3 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="dev.flutter.federated_plugin">
-    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
-    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
 </manifest>

experimental/federated_plugin/federated_plugin/android/src/main/kotlin/dev/flutter/federated_plugin/FederatedPlugin.kt

@@ -4,109 +4,55 @@
 
 package dev.flutter.federated_plugin
 
-import android.Manifest
-import android.app.Activity
 import android.content.Context
-import android.content.pm.PackageManager
+import android.content.Intent
+import android.content.IntentFilter
+import android.os.BatteryManager
+import android.os.Build
 import androidx.annotation.NonNull
-import androidx.core.app.ActivityCompat.requestPermissions
-import androidx.core.content.ContextCompat
-import com.google.android.gms.location.LocationServices.getFusedLocationProviderClient
 
 import io.flutter.embedding.engine.plugins.FlutterPlugin
-import io.flutter.embedding.engine.plugins.activity.ActivityAware
-import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding
 import io.flutter.plugin.common.MethodCall
 import io.flutter.plugin.common.MethodChannel
 import io.flutter.plugin.common.MethodChannel.MethodCallHandler
 import io.flutter.plugin.common.MethodChannel.Result
-import io.flutter.plugin.common.PluginRegistry
 
-
-class FederatedPlugin : FlutterPlugin, MethodCallHandler, ActivityAware, PluginRegistry.RequestPermissionsResultListener {
+class FederatedPlugin : FlutterPlugin, MethodCallHandler {
     private lateinit var channel: MethodChannel
-    private lateinit var context: Context
-    private lateinit var activity: Activity
-    private lateinit var result: Result
-    private val REQUEST_CODE = 1001
+    private var context: Context? = null
 
     override fun onAttachedToEngine(@NonNull flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) {
-        channel = MethodChannel(flutterPluginBinding.binaryMessenger, "location")
+        channel = MethodChannel(flutterPluginBinding.binaryMessenger, "battery")
         channel.setMethodCallHandler(this)
         context = flutterPluginBinding.applicationContext
     }
 
     override fun onMethodCall(@NonNull call: MethodCall, @NonNull result: Result) {
-        this.result = result
-        if (call.method == "getLocation") {
-            // Check for the runtime permission if SDK version is greater than 23. If permissions
-            // are granted, send the location data back to Dart. If permissions are not granted,
-            // request for the runtime permissions.
-            if (android.os.Build.VERSION.SDK_INT > android.os.Build.VERSION_CODES.LOLLIPOP && !checkPermissions()) {
-                requestPermissions(activity, arrayOf(
-                        Manifest.permission.ACCESS_FINE_LOCATION,
-                        Manifest.permission.ACCESS_COARSE_LOCATION
-                ), REQUEST_CODE)
-            } else {
-                provideLocation()
-            }
+        if (call.method == "getBatteryLevel") {
+            val batteryLevel: Int
+
+            batteryLevel = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+                val batteryManager = context?.getSystemService(Context.BATTERY_SERVICE) as BatteryManager
+                batteryManager.getIntProperty(BatteryManager.BATTERY_PROPERTY_CAPACITY)
             } else {
-            result.notImplemented()
+                val intent = IntentFilter(Intent.ACTION_BATTERY_CHANGED).let { intentFilter ->
+                    context?.registerReceiver(null, intentFilter)
                 }
+                intent!!.getIntExtra(BatteryManager.EXTRA_LEVEL, -1) * 100 / intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1)
             }
 
-    // Method to fetch and send the last known location of the device to Dart.
-    private fun provideLocation() {
-        getFusedLocationProviderClient(context).lastLocation
-                .addOnSuccessListener { location ->
-                    if (location != null) {
-                        result.success(listOf(location.longitude, location.latitude))
+            if (batteryLevel < 0) {
+                result.error("STATUS_UNAVAILABLE", "Not able to determine battery level.", null)
             } else {
-                        result.error("NOT_DETERMINED", "Not able to determine location", null)
-                    }
-                }.addOnFailureListener { exception ->
-                    result.error("Error", exception.message, null)
+                result.success(batteryLevel)
             }
+        } else {
+            result.notImplemented()
         }
-
-    // Method to check permissions to access the location data.
-    private fun checkPermissions(): Boolean {
-        val fineLocationPermission = ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION)
-        val coarseLocationPermission = ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION)
-
-        return fineLocationPermission == PackageManager.PERMISSION_GRANTED &&
-                coarseLocationPermission == PackageManager.PERMISSION_GRANTED
     }
 
-
     override fun onDetachedFromEngine(@NonNull binding: FlutterPlugin.FlutterPluginBinding) {
         channel.setMethodCallHandler(null)
-    }
-
-    override fun onDetachedFromActivity() {}
-
-    override fun onReattachedToActivityForConfigChanges(binding: ActivityPluginBinding) {
-        activity = binding.activity
-    }
-
-    override fun onAttachedToActivity(binding: ActivityPluginBinding) {
-        activity = binding.activity
-        binding.addRequestPermissionsResultListener(this)
-    }
-
-    override fun onDetachedFromActivityForConfigChanges() {}
-
-    // Callback for the result after requesting for runtime permissions. If permissions
-    // are granted, send the location data, or send an error back to Dart if permissions
-    // are not granted.
-    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>?, grantResults: IntArray): Boolean {
-        if (requestCode == REQUEST_CODE && grantResults.isNotEmpty()) {
-            if (grantResults[0] == PackageManager.PERMISSION_GRANTED && grantResults[1] == PackageManager.PERMISSION_GRANTED) {
-                provideLocation()
-            } else {
-                result.error("PERMISSION_DENIED", "Permission denied from User", null)
-            }
-        }
-        return false
+        context = null
     }
 }

experimental/federated_plugin/federated_plugin/example/lib/main.dart

@@ -18,15 +18,15 @@ class MyApp extends StatelessWidget {
   }
 }
 
-/// Demonstrates how to use the getLocation method from federated_plugin to access
-/// location data.
+/// Demonstrates how to use the getBatteryLevel method from federated_plugin to retrieve
+/// current battery level of device.
 class HomePage extends StatefulWidget {
   @override
   _HomePageState createState() => _HomePageState();
 }
 
 class _HomePageState extends State<HomePage> {
-  Location location;
+  int batteryLevel;
 
   @override
   Widget build(BuildContext context) {
@@ -40,21 +40,20 @@ class _HomePageState extends State<HomePage> {
             child: Column(
               mainAxisAlignment: MainAxisAlignment.center,
               children: [
-                location == null
+                batteryLevel == null
                     ? SizedBox.shrink()
                     : Text(
-                        'Latitude: ${location.latitude}\n'
-                        'Longitude: ${location.longitude}',
+                        'Battery Level: $batteryLevel',
                         style: Theme.of(context).textTheme.headline5,
                       ),
                 SizedBox(height: 16),
                 RaisedButton(
-                  child: Text('Get Location'),
+                  child: Text('Get Battery Level'),
                   onPressed: () async {
                     try {
-                      final result = await getLocation();
+                      final result = await getBatteryLevel();
                       setState(() {
-                        location = result;
+                        batteryLevel = result;
                       });
                     } catch (error) {
                       Scaffold.of(context).showSnackBar(

experimental/federated_plugin/federated_plugin/example/test/widget_test.dart

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:federated_plugin/federated_plugin.dart';
 import 'package:federated_plugin_example/main.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
@@ -10,27 +9,23 @@ import 'package:flutter_test/flutter_test.dart';
 
 void main() {
   group('federated plugin demo tests', () {
-    final location = Location(latitude: 131.0, longitude: 221.0);
+    final batteryLevel = 45;
     setUpAll(() {
-      MethodChannel('location').setMockMethodCallHandler((call) async {
-        if (call.method == 'getLocation') {
-          return [location.longitude, location.latitude];
+      MethodChannel('battery').setMockMethodCallHandler((call) async {
+        if (call.method == 'getBatteryLevel') {
+          return batteryLevel;
         }
       });
     });
 
-    testWidgets('get location from platform', (tester) async {
+    testWidgets('get current battery level from platform', (tester) async {
       await tester.pumpWidget(MyApp());
 
-      // Tap button to get location from platform.
+      // Tap button to retrieve current battery level from platform.
       await tester.tap(find.byType(RaisedButton));
       await tester.pumpAndSettle();
 
-      expect(
-        find.text('Latitude: ${location.latitude}\n'
-            'Longitude: ${location.longitude}'),
-        findsOneWidget,
-      );
+      expect(find.text('Battery Level: $batteryLevel'), findsOneWidget);
     });
   });
 }

experimental/federated_plugin/federated_plugin/lib/federated_plugin.dart

@@ -5,12 +5,10 @@
 import 'dart:async';
 
 import 'package:federated_plugin_platform_interface/federated_plugin_platform_interface.dart';
-import 'package:federated_plugin_platform_interface/location_model.dart';
-export 'package:federated_plugin_platform_interface/location_model.dart';
 
-/// Returns [Location] to provide latitude and longitude.
+/// Returns the current battery level of device.
 ///
-/// It uses [FederatedPluginInterface] interface to provide location.
-Future<Location> getLocation() async {
-  return await FederatedPluginInterface.instance.getLocation();
+/// It uses [FederatedPluginInterface] interface to provide current battery level.
+Future<int> getBatteryLevel() async {
+  return await FederatedPluginInterface.instance.getBatteryLevel();
 }

experimental/federated_plugin/federated_plugin/test/federated_plugin_test.dart

@@ -10,17 +10,16 @@ void main() {
   TestWidgetsFlutterBinding.ensureInitialized();
 
   group('Federated Plugin Test', () {
-    final location = Location(latitude: 131.0, longitude: 221.0);
-    MethodChannel('location').setMockMethodCallHandler((call) async {
-      if (call.method == 'getLocation') {
-        return [location.longitude, location.latitude];
+    final batteryLevel = 34;
+    MethodChannel('battery').setMockMethodCallHandler((call) async {
+      if (call.method == 'getBatteryLevel') {
+        return batteryLevel;
       }
     });
 
-    test('getLocation method test', () async {
-      final result = await getLocation();
-      expect(result.longitude, location.longitude);
-      expect(result.latitude, location.latitude);
+    test('getBatteryLevel method test', () async {
+      final result = await getBatteryLevel();
+      expect(result, batteryLevel);
     });
   });
 }

experimental/federated_plugin/federated_plugin_platform_interface/lib/battery_method_channel.dart

@@ -0,0 +1,17 @@
+// Copyright 2020 The Flutter team. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:federated_plugin_platform_interface/federated_plugin_platform_interface.dart';
+import 'package:flutter/services.dart';
+
+/// Implements [FederatedPluginInterface] using [MethodChannel] to fetch
+/// battery level from platform.
+class BatteryMethodChannel extends FederatedPluginInterface {
+  static const MethodChannel _methodChannel = MethodChannel('battery');
+
+  @override
+  Future<int> getBatteryLevel() async {
+    return await _methodChannel.invokeMethod<int>('getBatteryLevel');
+  }
+}

experimental/federated_plugin/federated_plugin_platform_interface/lib/federated_plugin_platform_interface.dart

@@ -2,8 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:federated_plugin_platform_interface/location_method_channel.dart';
-import 'package:federated_plugin_platform_interface/location_model.dart';
+import 'package:federated_plugin_platform_interface/battery_method_channel.dart';
 import 'package:plugin_platform_interface/plugin_platform_interface.dart';
 
 /// Interface which allows all the platform plugins to implement the same
@@ -12,11 +11,11 @@ abstract class FederatedPluginInterface extends PlatformInterface {
   FederatedPluginInterface() : super(token: _object);
 
   static FederatedPluginInterface _federatedPluginInterface =
-      LocationMethodChannel();
+      BatteryMethodChannel();
 
   static final Object _object = Object();
 
-  /// Provides instance of [LocationMethodChannel] to invoke platform calls.
+  /// Provides instance of [BatteryMethodChannel] to invoke platform calls.
   static FederatedPluginInterface get instance => _federatedPluginInterface;
 
   static set instance(FederatedPluginInterface instance) {
@@ -24,8 +23,8 @@ abstract class FederatedPluginInterface extends PlatformInterface {
     _federatedPluginInterface = instance;
   }
 
-  /// Returns [Location] to provide latitude and longitude.
-  Future<Location> getLocation() async {
-    throw UnimplementedError('getLocation() has not been implemented.');
+  /// Returns the current battery level of device.
+  Future<int> getBatteryLevel() async {
+    throw UnimplementedError('getBatteryLevel() has not been implemented.');
   }
 }

experimental/federated_plugin/federated_plugin_platform_interface/lib/location_method_channel.dart

@@ -1,24 +0,0 @@
-// Copyright 2020 The Flutter team. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-import 'package:federated_plugin_platform_interface/federated_plugin_platform_interface.dart';
-import 'package:federated_plugin_platform_interface/location_model.dart';
-import 'package:flutter/services.dart';
-
-/// Implements [FederatedPluginInterface] using [MethodChannel] to fetch
-/// location from platform.
-class LocationMethodChannel extends FederatedPluginInterface {
-  static const MethodChannel _methodChannel = MethodChannel('location');
-
-  @override
-  Future<Location> getLocation() async {
-    final result =
-        await _methodChannel.invokeMethod<List<dynamic>>('getLocation');
-
-    return Location(
-      longitude: result.first as double,
-      latitude: result.last as double,
-    );
-  }
-}

experimental/federated_plugin/federated_plugin_platform_interface/lib/location_model.dart

@@ -1,11 +0,0 @@
-// Copyright 2020 The Flutter team. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-/// Model to hold the incoming latitude and longitude values from platform.
-class Location {
-  final double latitude;
-  final double longitude;
-
-  Location({this.latitude, this.longitude});
-}

experimental/federated_plugin/federated_plugin_platform_interface/test/federated_plugin_platform_interface_test.dart

@@ -2,8 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:federated_plugin_platform_interface/location_method_channel.dart';
-import 'package:federated_plugin_platform_interface/location_model.dart';
+import 'package:federated_plugin_platform_interface/battery_method_channel.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 
@@ -11,18 +10,17 @@ void main() {
   TestWidgetsFlutterBinding.ensureInitialized();
 
   group('MethodChannel test', () {
-    final location = Location(latitude: 1.0, longitude: 2.0);
-    MethodChannel('location').setMockMethodCallHandler((call) async {
-      if (call.method == 'getLocation') {
-        return [location.longitude, location.latitude];
+    final batteryLevel = 89;
+    MethodChannel('battery').setMockMethodCallHandler((call) async {
+      if (call.method == 'getBatteryLevel') {
+        return batteryLevel;
       }
     });
 
-    test('getLocation method test', () async {
-      final locationMethodChannel = LocationMethodChannel();
-      final result = await locationMethodChannel.getLocation();
-      expect(result.longitude, location.longitude);
-      expect(result.latitude, result.latitude);
+    test('getBatteryLevel method test', () async {
+      final locationMethodChannel = BatteryMethodChannel();
+      final result = await locationMethodChannel.getBatteryLevel();
+      expect(result, batteryLevel);
     });
   });
 }

experimental/federated_plugin/federated_plugin_web/.gitignore

@@ -67,6 +67,9 @@ build/
 **/ios/ServiceDefinitions.json
 **/ios/Runner/GeneratedPluginRegistrant.*
 
+# Web related
+lib/generated_plugin_registrant.dart
+
 # Exceptions to above rules.
 !**/ios/**/default.mode1v3
 !**/ios/**/default.mode2v3

experimental/federated_plugin/federated_plugin_web/lib/federated_plugin_web.dart

@@ -5,17 +5,17 @@
 import 'dart:html' as html;
 
 import 'package:federated_plugin_platform_interface/federated_plugin_platform_interface.dart';
-import 'package:federated_plugin_platform_interface/location_model.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_web_plugins/flutter_web_plugins.dart';
 
-/// Web Implementation of [FederatedPluginInterface] to provide location.
+/// Web Implementation of [FederatedPluginInterface] to retrieve current battery
+/// level of device.
 class FederatedPlugin extends FederatedPluginInterface {
-  final html.Geolocation _geolocation;
+  final html.Navigator _navigator;
 
-  /// Constructor to override the geolocation object for testing purpose.
-  FederatedPlugin({html.Geolocation geolocation})
-      : _geolocation = geolocation ?? html.window.navigator.geolocation;
+  /// Constructor to override the navigator object for testing purpose.
+  FederatedPlugin({html.Navigator navigator})
+      : _navigator = navigator ?? html.window.navigator;
 
   /// Method to register the plugin which sets [FederatedPlugin] to be the default
   /// instance of [FederatedPluginInterface].
@@ -23,21 +23,20 @@ class FederatedPlugin extends FederatedPluginInterface {
     FederatedPluginInterface.instance = FederatedPlugin();
   }
 
-  /// Returns [Location] to provide latitude and longitude.
+  /// Returns the current battery level of device.
   ///
-  /// If any error, it's assume that user has denied the permission forever.
+  /// If any error, it's assume that the BatteryManager API is not supported by
+  /// browser.
   @override
-  Future<Location> getLocation() async {
+  Future<int> getBatteryLevel() async {
     try {
-      final geoPosition = await _geolocation.getCurrentPosition();
-      return Location(
-        longitude: geoPosition.coords.longitude.toDouble(),
-        latitude: geoPosition.coords.latitude.toDouble(),
-      );
+      final battery = await _navigator.getBattery() as html.BatteryManager;
+      // The battery level retrieved is in range of 0.0 to 1.0.
+      return battery.level * 100 as int;
     } catch (error) {
       throw PlatformException(
-        code: 'PERMISSION_DENIED',
-        message: 'Permission denied from User',
+        code: 'STATUS_UNAVAILABLE',
+        message: 'The plugin is not supported by the browser.',
         details: null,
       );
     }

experimental/federated_plugin/federated_plugin_web/pubspec.yaml

@@ -1,5 +1,5 @@
 name: federated_plugin_web
-description: Web implementation of federated_plugin to provide location.
+description: Web implementation of federated_plugin to retrieve current battery level.
 version: 0.0.1
 homepage:
 publish_to: none

experimental/federated_plugin/federated_plugin_web/test_driver/federated_plugin_web_e2e.dart

@@ -9,45 +9,35 @@ import 'package:federated_plugin_web/federated_plugin_web.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:mockito/mockito.dart';
 
-const kLatitude = 4;
-const kLongitude = 3;
+const kBatteryLevel = 0.49;
 
-class GeoLocationMock extends Mock implements Geolocation {}
+class NavigatorMock extends Mock implements Navigator {}
 
-class GeoPositionMock extends Mock implements Geoposition {
+class BatteryManagerMock extends Mock implements BatteryManager {
   @override
-  Coordinates get coords => MockCoordinates();
-}
-
-class MockCoordinates extends Mock implements Coordinates {
-  @override
-  num get latitude => kLatitude;
-
-  @override
-  num get longitude => kLongitude;
+  num get level => kBatteryLevel;
 }
 
 void main() {
   E2EWidgetsFlutterBinding.ensureInitialized();
 
   group('FederatedPlugin test', () {
-    final geoLocationMock = GeoLocationMock();
+    final navigatorMock = NavigatorMock();
 
     setUp(() {
-      when(geoLocationMock.getCurrentPosition())
-          .thenAnswer((realInvocation) async => GeoPositionMock());
+      when(navigatorMock.getBattery())
+          .thenAnswer((realInvocation) async => BatteryManagerMock());
     });
 
-    testWidgets('getLocation Method', (tester) async {
-      final federatedPlugin = FederatedPlugin(geolocation: geoLocationMock);
-      final location = await federatedPlugin.getLocation();
+    testWidgets('getBatteryLevel Method', (tester) async {
+      final federatedPlugin = FederatedPlugin(navigator: navigatorMock);
+      final batteryLevel = await federatedPlugin.getBatteryLevel();
 
-      // Verify that getCurrentPosition was called.
-      verify(geoLocationMock.getCurrentPosition());
+      // Verify that getBattery was called.
+      verify(navigatorMock.getBattery());
 
-      // Verify the values of Location.longitude and Location.latitude.
-      expect(location.longitude, kLongitude);
-      expect(location.latitude, kLatitude);
+      // Verify the battery level.
+      expect(batteryLevel, kBatteryLevel * 100);
     });
   });
 }