address comments

packages/firebase_messaging/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 5.1.5
+
+* Enable background message handling on Android.
+
 ## 5.1.4
 
 * Update documentation to reflect new repository location.

packages/firebase_messaging/README.md

@@ -56,6 +56,11 @@ Note: When you are debugging on Android, use a device or AVD with Google Play se
   ```
 #### Optionally handle background messages
 
+>Background message handling is intended to be performed quickly. Do not perform
+long running tasks as they may not be allowed to finish by the Android system.
+See [Background Execution Limits](https://developer.android.com/about/versions/oreo/background)
+for more.
+
 By default background messaging is not enabled. To handle messages in the background:
 
 1. Add an Application.java class to your app

packages/firebase_messaging/android/src/main/java/io/flutter/plugins/firebasemessaging/FlutterFirebaseMessagingService.java

@@ -44,37 +44,37 @@ public class FlutterFirebaseMessagingService extends FirebaseMessagingService {
   private static final String BACKGROUND_MESSAGE_CALLBACK_HANDLE_KEY =
       "background_message_callback";
 
-  // TODO(kroikie): make sIsIsolateRunning per-instance, not static.
-  private static AtomicBoolean sIsIsolateRunning = new AtomicBoolean(false);
+  // TODO(kroikie): make isIsolateRunning per-instance, not static.
+  private static AtomicBoolean isIsolateRunning = new AtomicBoolean(false);
 
   /** Background Dart execution context. */
-  private static FlutterNativeView sBackgroundFlutterView;
+  private static FlutterNativeView backgroundFlutterView;
 
-  private static MethodChannel sBackgroundChannel;
+  private static MethodChannel backgroundChannel;
 
-  private static Long sBackgroundMessageHandle;
+  private static Long backgroundMessageHandle;
 
-  private static List<RemoteMessage> sBackgroundMessageQueue =
+  private static List<RemoteMessage> backgroundMessageQueue =
       Collections.synchronizedList(new LinkedList<RemoteMessage>());
 
-  private static PluginRegistry.PluginRegistrantCallback sPluginRegistrantCallback;
+  private static PluginRegistry.PluginRegistrantCallback pluginRegistrantCallback;
 
   private static final String TAG = "FlutterFcmService";
 
-  private static Context sBackgroundContext;
+  private static Context backgroundContext;
 
   @Override
   public void onCreate() {
     super.onCreate();
 
-    sBackgroundContext = getApplicationContext();
-    FlutterMain.ensureInitializationComplete(sBackgroundContext, null);
+    backgroundContext = getApplicationContext();
+    FlutterMain.ensureInitializationComplete(backgroundContext, null);
 
     // If background isolate is not running start it.
-    if (!sIsIsolateRunning.get()) {
-      SharedPreferences p = sBackgroundContext.getSharedPreferences(SHARED_PREFERENCES_KEY, 0);
+    if (!isIsolateRunning.get()) {
+      SharedPreferences p = backgroundContext.getSharedPreferences(SHARED_PREFERENCES_KEY, 0);
       long callbackHandle = p.getLong(BACKGROUND_SETUP_CALLBACK_HANDLE_KEY, 0);
-      startBackgroundIsolate(sBackgroundContext, callbackHandle);
+      startBackgroundIsolate(backgroundContext, callbackHandle);
     }
   }
 
@@ -94,8 +94,8 @@ public void onMessageReceived(final RemoteMessage remoteMessage) {
     } else {
       // If background isolate is not running yet, put message in queue and it will be handled
       // when the isolate starts.
-      if (!sIsIsolateRunning.get()) {
-        sBackgroundMessageQueue.add(remoteMessage);
+      if (!isIsolateRunning.get()) {
+        backgroundMessageQueue.add(remoteMessage);
       } else {
         final CountDownLatch latch = new CountDownLatch(1);
         new Handler(getMainLooper())
@@ -151,17 +151,17 @@ public static void startBackgroundIsolate(Context context, long callbackHandle)
     // Note that we're passing `true` as the second argument to our
     // FlutterNativeView constructor. This specifies the FlutterNativeView
     // as a background view and does not create a drawing surface.
-    sBackgroundFlutterView = new FlutterNativeView(context, true);
-    if (appBundlePath != null && !sIsIsolateRunning.get()) {
-      if (sPluginRegistrantCallback == null) {
+    backgroundFlutterView = new FlutterNativeView(context, true);
+    if (appBundlePath != null && !isIsolateRunning.get()) {
+      if (pluginRegistrantCallback == null) {
         throw new RuntimeException("PluginRegistrantCallback is not set.");
       }
       FlutterRunArguments args = new FlutterRunArguments();
       args.bundlePath = appBundlePath;
       args.entrypoint = flutterCallback.callbackName;
       args.libraryPath = flutterCallback.callbackLibraryPath;
-      sBackgroundFlutterView.runFromBundle(args);
-      sPluginRegistrantCallback.registerWith(sBackgroundFlutterView.getPluginRegistry());
+      backgroundFlutterView.runFromBundle(args);
+      pluginRegistrantCallback.registerWith(backgroundFlutterView.getPluginRegistry());
     }
   }
 
@@ -170,15 +170,15 @@ public static void startBackgroundIsolate(Context context, long callbackHandle)
    * Dart side once all background initialization is complete via `FcmDartService#initialized`.
    */
   public static void onInitialized() {
-    sIsIsolateRunning.set(true);
-    synchronized (sBackgroundMessageQueue) {
+    isIsolateRunning.set(true);
+    synchronized (backgroundMessageQueue) {
       // Handle all the messages received before the Dart isolate was
       // initialized, then clear the queue.
-      Iterator<RemoteMessage> i = sBackgroundMessageQueue.iterator();
+      Iterator<RemoteMessage> i = backgroundMessageQueue.iterator();
       while (i.hasNext()) {
-        executeDartCallbackInBackgroundIsolate(sBackgroundContext, i.next(), null);
+        executeDartCallbackInBackgroundIsolate(backgroundContext, i.next(), null);
       }
-      sBackgroundMessageQueue.clear();
+      backgroundMessageQueue.clear();
     }
   }
 
@@ -189,7 +189,7 @@ public static void onInitialized() {
    * @param channel Background method channel.
    */
   public static void setBackgroundChannel(MethodChannel channel) {
-    sBackgroundChannel = channel;
+    backgroundChannel = channel;
   }
 
   /**
@@ -201,7 +201,7 @@ public static void setBackgroundChannel(MethodChannel channel) {
    * @param handle Handle representing the Dart side method that will handle background messages.
    */
   public static void setBackgroundMessageHandle(Context context, Long handle) {
-    sBackgroundMessageHandle = handle;
+    backgroundMessageHandle = handle;
 
     // Store background message handle in shared preferences so it can be retrieved
     // by other application instances.
@@ -255,7 +255,7 @@ public static Long getBackgroundMessageHandle(Context context) {
    */
   private static void executeDartCallbackInBackgroundIsolate(
       Context context, RemoteMessage remoteMessage, final CountDownLatch latch) {
-    if (sBackgroundChannel == null) {
+    if (backgroundChannel == null) {
       throw new RuntimeException(
           "setBackgroundChannel was not called before messages came in, exiting.");
     }
@@ -268,10 +268,10 @@ private static void executeDartCallbackInBackgroundIsolate(
 
     Map<String, Object> args = new HashMap<>();
     Map<String, Object> messageData = new HashMap<>();
-    if (sBackgroundMessageHandle == null) {
-      sBackgroundMessageHandle = getBackgroundMessageHandle(context);
+    if (backgroundMessageHandle == null) {
+      backgroundMessageHandle = getBackgroundMessageHandle(context);
     }
-    args.put("handle", sBackgroundMessageHandle);
+    args.put("handle", backgroundMessageHandle);
 
     if (remoteMessage.getData() != null) {
       messageData.put("data", remoteMessage.getData());
@@ -282,7 +282,7 @@ private static void executeDartCallbackInBackgroundIsolate(
 
     args.put("message", messageData);
 
-    sBackgroundChannel.invokeMethod("handleBackgroundMessage", args, result);
+    backgroundChannel.invokeMethod("handleBackgroundMessage", args, result);
   }
 
   /**
@@ -292,7 +292,7 @@ private static void executeDartCallbackInBackgroundIsolate(
    * @param callback Application class which implements PluginRegistrantCallback.
    */
   public static void setPluginRegistrant(PluginRegistry.PluginRegistrantCallback callback) {
-    sPluginRegistrantCallback = callback;
+    pluginRegistrantCallback = callback;
   }
 
   /**

packages/firebase_messaging/android/src/main/java/io/flutter/plugins/firebasemessaging/LatchResult.java

@@ -1,35 +1,33 @@
 package io.flutter.plugins.firebasemessaging;
 
-import java.util.concurrent.CountDownLatch;
-
 import io.flutter.plugin.common.MethodChannel;
+import java.util.concurrent.CountDownLatch;
 
 public class LatchResult {
 
   private MethodChannel.Result result;
 
   public LatchResult(final CountDownLatch latch) {
-    result = new MethodChannel.Result() {
-      @Override
-      public void success(Object result) {
-        latch.countDown();
-      }
-
-      @Override
-      public void error(String errorCode, String errorMessage, Object errorDetails) {
-        latch.countDown();
-      }
-
-      @Override
-      public void notImplemented() {
-        latch.countDown();
-      }
-    };
+    result =
+        new MethodChannel.Result() {
+          @Override
+          public void success(Object result) {
+            latch.countDown();
+          }
+
+          @Override
+          public void error(String errorCode, String errorMessage, Object errorDetails) {
+            latch.countDown();
+          }
+
+          @Override
+          public void notImplemented() {
+            latch.countDown();
+          }
+        };
   }
 
   public MethodChannel.Result getResult() {
     return result;
   }
-
-
 }

packages/firebase_messaging/lib/firebase_messaging.dart

@@ -13,51 +13,51 @@ import 'package:platform/platform.dart';
 
 typedef Future<dynamic> MessageHandler(Map<String, dynamic> message);
 
-/// Setup method channel to handle Firebase Cloud Messages received while
-/// the Flutter app is not active. The handle for this method is generated
-/// and passed to the Android side so that the background isolate knows where
-/// to send background messages for processing.
-///
-/// Your app should never call this method directly, this is only for use
-/// by the firebase_messaging plugin to setup background message handling.
-@visibleForTesting
-Future<void> fcmSetupBackgroundChannel(
-    {MethodChannel backgroundChannel = const MethodChannel(
-        'plugins.flutter.io/firebase_messaging_background')}) async {
-  // Setup Flutter state needed for MethodChannels.
-  WidgetsFlutterBinding.ensureInitialized();
-
-  // This is where the magic happens and we handle background events from the
-  // native portion of the plugin.
-  backgroundChannel.setMethodCallHandler((MethodCall call) async {
-    if (call.method == 'handleBackgroundMessage') {
-      final CallbackHandle handle =
-          CallbackHandle.fromRawHandle(call.arguments['handle']);
-      final Function handlerFunction =
-          PluginUtilities.getCallbackFromHandle(handle);
-      try {
-        await handlerFunction(
-            Map<String, dynamic>.from(call.arguments['message']));
-      } catch (e) {
-        print('Unable to handle incoming background message.');
-        print(e);
-      }
-      return Future<void>.value();
-    }
-  });
-
-// Once we've finished initializing, let the native portion of the plugin
-// know that it can start scheduling handling messages.
-  await backgroundChannel.invokeMethod<void>('FcmDartService#initialized');
-}
-
 /// Implementation of the Firebase Cloud Messaging API for Flutter.
 ///
 /// Your app should call [requestNotificationPermissions] first and then
 /// register handlers for incoming messages with [configure].
 class FirebaseMessaging {
   factory FirebaseMessaging() => _instance;
 
+  /// Setup method channel to handle Firebase Cloud Messages received while
+  /// the Flutter app is not active. The handle for this method is generated
+  /// and passed to the Android side so that the background isolate knows where
+  /// to send background messages for processing.
+  ///
+  /// Your app should never call this method directly, this is only for use
+  /// by the firebase_messaging plugin to setup background message handling.
+  @visibleForTesting
+  static void fcmSetupBackgroundChannel(
+      {MethodChannel backgroundChannel = const MethodChannel(
+          'plugins.flutter.io/firebase_messaging_background')}) async {
+    // Setup Flutter state needed for MethodChannels.
+    WidgetsFlutterBinding.ensureInitialized();
+
+    // This is where the magic happens and we handle background events from the
+    // native portion of the plugin.
+    backgroundChannel.setMethodCallHandler((MethodCall call) async {
+      if (call.method == 'handleBackgroundMessage') {
+        final CallbackHandle handle =
+            CallbackHandle.fromRawHandle(call.arguments['handle']);
+        final Function handlerFunction =
+            PluginUtilities.getCallbackFromHandle(handle);
+        try {
+          await handlerFunction(
+              Map<String, dynamic>.from(call.arguments['message']));
+        } catch (e) {
+          print('Unable to handle incoming background message.');
+          print(e);
+        }
+        return Future<void>.value();
+      }
+    });
+
+    // Once we've finished initializing, let the native portion of the plugin
+    // know that it can start scheduling handling messages.
+    backgroundChannel.invokeMethod<void>('FcmDartService#initialized');
+  }
+
   @visibleForTesting
   FirebaseMessaging.private(MethodChannel channel, Platform platform)
       : _channel = channel,

packages/firebase_messaging/pubspec.yaml

@@ -3,7 +3,7 @@ description: Flutter plugin for Firebase Cloud Messaging, a cross-platform
   messaging solution that lets you reliably deliver messages on Android and iOS.
 author: Flutter Team <[email protected]>
 homepage: https://github.com/FirebaseExtended/flutterfire/tree/master/packages/firebase_messaging
-version: 5.1.4
+version: 5.1.5
 
 flutter:
   plugin:

packages/firebase_messaging/test/firebase_messaging_test.dart

@@ -170,7 +170,8 @@ void main() {
   });
 
   test('setupBackgroundCallback', () {
-    fcmSetupBackgroundChannel(backgroundChannel: mockBackgroundChannel);
+    FirebaseMessaging.fcmSetupBackgroundChannel(
+        backgroundChannel: mockBackgroundChannel);
     verify(
         mockBackgroundChannel.invokeMethod<void>('FcmDartService#initialized'));
   });