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

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)
+        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 {
-                provideLocation()
+                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)
+            }
+
+            if (batteryLevel < 0) {
+                result.error("STATUS_UNAVAILABLE", "Not able to determine battery level.", null)
+            } else {
+                result.success(batteryLevel)
             }
         } else {
             result.notImplemented()
         }
     }
 
-    // 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))
-                    } else {
-                        result.error("NOT_DETERMINED", "Not able to determine location", null)
-                    }
-                }.addOnFailureListener { exception ->
-                    result.error("Error", exception.message, null)
-                }
-    }
-
-    // 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);
     });
   });
 }