Show notifications! on Android, in foreground

ios/Podfile.lock

@@ -70,6 +70,8 @@ PODS:
     - GoogleUtilities/UserDefaults (~> 7.8)
     - nanopb (< 2.30910.0, >= 2.30908.0)
   - Flutter (1.0.0)
+  - flutter_local_notifications (0.0.1):
+    - Flutter
   - GoogleDataTransport (9.2.5):
     - GoogleUtilities/Environment (~> 7.7)
     - nanopb (< 2.30910.0, >= 2.30908.0)
@@ -135,6 +137,7 @@ DEPENDENCIES:
   - firebase_core (from `.symlinks/plugins/firebase_core/ios`)
   - firebase_messaging (from `.symlinks/plugins/firebase_messaging/ios`)
   - Flutter (from `Flutter`)
+  - flutter_local_notifications (from `.symlinks/plugins/flutter_local_notifications/ios`)
   - image_picker_ios (from `.symlinks/plugins/image_picker_ios/ios`)
   - package_info_plus (from `.symlinks/plugins/package_info_plus/ios`)
   - path_provider_foundation (from `.symlinks/plugins/path_provider_foundation/darwin`)
@@ -172,6 +175,8 @@ EXTERNAL SOURCES:
     :path: ".symlinks/plugins/firebase_messaging/ios"
   Flutter:
     :path: Flutter
+  flutter_local_notifications:
+    :path: ".symlinks/plugins/flutter_local_notifications/ios"
   image_picker_ios:
     :path: ".symlinks/plugins/image_picker_ios/ios"
   package_info_plus:
@@ -199,6 +204,7 @@ SPEC CHECKSUMS:
   FirebaseInstallations: b822f91a61f7d1ba763e5ccc9d4f2e6f2ed3b3ee
   FirebaseMessaging: 80b4a086d20ed4fd385a702f4bfa920e14f5064d
   Flutter: f04841e97a9d0b0a8025694d0796dd46242b2854
+  flutter_local_notifications: 0c0b1ae97e741e1521e4c1629a459d04b9aec743
   GoogleDataTransport: 54dee9d48d14580407f8f5fbf2f496e92437a2f2
   GoogleUtilities: 13e2c67ede716b8741c7989e26893d151b2b2084
   image_picker_ios: 4a8aadfbb6dc30ad5141a2ce3832af9214a705b5

lib/model/binding.dart

@@ -2,6 +2,7 @@ import 'package:device_info_plus/device_info_plus.dart' as device_info_plus;
 import 'package:firebase_core/firebase_core.dart' as firebase_core;
 import 'package:firebase_messaging/firebase_messaging.dart' as firebase_messaging;
 import 'package:flutter/foundation.dart';
+import 'package:flutter_local_notifications/flutter_local_notifications.dart';
 import 'package:url_launcher/url_launcher.dart' as url_launcher;
 
 import '../firebase_options.dart';
@@ -98,6 +99,9 @@ abstract class ZulipBinding {
 
   /// Wraps [firebase_messaging.FirebaseMessaging.onMessage].
   Stream<firebase_messaging.RemoteMessage> get firebaseMessagingOnMessage;
+
+  /// Wraps the [FlutterLocalNotificationsPlugin] singleton constructor.
+  FlutterLocalNotificationsPlugin get notifications;
 }
 
 /// Like [device_info_plus.BaseDeviceInfo], but without things we don't use.
@@ -194,4 +198,7 @@ class LiveZulipBinding extends ZulipBinding {
   Stream<firebase_messaging.RemoteMessage> get firebaseMessagingOnMessage {
     return firebase_messaging.FirebaseMessaging.onMessage;
   }
+
+  @override
+  FlutterLocalNotificationsPlugin get notifications => FlutterLocalNotificationsPlugin();
 }

lib/notifications.dart

@@ -1,8 +1,10 @@
 import 'package:flutter/foundation.dart';
+import 'package:flutter_local_notifications/flutter_local_notifications.dart';
 
 import 'api/notifications.dart';
 import 'log.dart';
 import 'model/binding.dart';
+import 'widgets/app.dart';
 
 class NotificationService {
   static NotificationService get instance => (_instance ??= NotificationService._());
@@ -38,6 +40,7 @@ class NotificationService {
     // TODO(#324) defer notif setup if user not logged into any accounts
     //   (in order to avoid calling for permissions)
 
+    await NotificationDisplayManager._init();
     ZulipBinding.instance.firebaseMessagingOnMessage.listen(_onRemoteMessage);
 
     // Get the FCM registration token, now and upon changes.  See FCM API docs:
@@ -71,9 +74,121 @@ class NotificationService {
   static void _onRemoteMessage(FirebaseRemoteMessage message) {
     assert(debugLog("notif message: ${message.data}"));
     final data = FcmMessage.fromJson(message.data);
-    if (data is MessageFcmMessage) {
-      assert(debugLog('notif message content: ${data.content}'));
-      // TODO(#122): show notification UI
+    switch (data) {
+      case MessageFcmMessage(): NotificationDisplayManager._onMessageFcmMessage(data, message.data);
+      case RemoveFcmMessage(): break; // TODO(#341) handle
+      case UnexpectedFcmMessage(): break; // TODO(log)
     }
   }
 }
+
+/// Service for configuring our Android "notification channel".
+class NotificationChannelManager {
+  @visibleForTesting
+  static const kChannelId = 'messages-1';
+
+  /// The vibration pattern we set for notifications.
+  // We try to set a vibration pattern that, with the phone in one's pocket,
+  // is both distinctly present and distinctly different from the default.
+  // Discussion: https://chat.zulip.org/#narrow/stream/48-mobile/topic/notification.20vibration.20pattern/near/1284530
+  @visibleForTesting
+  static final kVibrationPattern = Int64List.fromList([0, 125, 100, 450]);
+
+  /// Create our notification channel, if it doesn't already exist.
+  //
+  // NOTE when changing anything here: the changes will not take effect
+  // for existing installs of the app!  That's because we'll have already
+  // created the channel with the old settings, and they're in the user's
+  // hands from there.  Our choices are:
+  //
+  //  * Leave the old settings in place for existing installs, so the
+  //    changes only apply to new installs.
+  //
+  //  * Change `kChannelId`, so that we abandon the old channel and use
+  //    a new one.  Existing installs will get the new settings.
+  //
+  //    This also means that if the user has changed any of the notification
+  //    settings for the channel -- like "override Do Not Disturb", or "use
+  //    a different sound", or "don't pop on screen" -- their changes get
+  //    reset.  So this has to be done sparingly.
+  //
+  //    If we do this, we should also look for any channel with the old
+  //    channel ID and delete it.  See zulip-mobile's `createNotificationChannel`
+  //    in android/app/src/main/java/com/zulipmobile/notifications/NotificationChannelManager.kt .
+  static Future<void> _ensureChannel() async {
+    final plugin = ZulipBinding.instance.notifications;
+    await plugin.resolvePlatformSpecificImplementation<AndroidFlutterLocalNotificationsPlugin>()
+      ?.createNotificationChannel(AndroidNotificationChannel(
+        kChannelId,
+        'Messages', // TODO(i18n)
+        importance: Importance.high,
+        enableLights: true,
+        vibrationPattern: kVibrationPattern,
+        // TODO(#340) sound
+      ));
+  }
+}
+
+/// Service for managing the notifications shown to the user.
+class NotificationDisplayManager {
+  // We rely on the tag instead.
+  @visibleForTesting
+  static const kNotificationId = 0;
+
+  static Future<void> _init() async {
+    await ZulipBinding.instance.notifications.initialize(
+      const InitializationSettings(
+        android: AndroidInitializationSettings('zulip_notification'),
+      ),
+    );
+    await NotificationChannelManager._ensureChannel();
+  }
+
+  static void _onMessageFcmMessage(MessageFcmMessage data, Map<String, dynamic> dataJson) {
+    assert(debugLog('notif message content: ${data.content}'));
+    final title = switch (data.recipient) {
+      FcmMessageStreamRecipient(:var streamName?, :var topic) =>
+        '$streamName > $topic',
+      FcmMessageStreamRecipient(:var topic) =>
+        '(unknown stream) > $topic', // TODO get stream name from data
+      FcmMessageDmRecipient(:var allRecipientIds) when allRecipientIds.length > 2 =>
+        '${data.senderFullName} to you and ${allRecipientIds.length - 2} others', // TODO(i18n), also plural; TODO use others' names, from data
+      FcmMessageDmRecipient() =>
+        data.senderFullName,
+    };
+    ZulipBinding.instance.notifications.show(
+      kNotificationId,
+      title,
+      data.content,
+      NotificationDetails(android: AndroidNotificationDetails(
+        NotificationChannelManager.kChannelId,
+        // This [FlutterLocalNotificationsPlugin.show] call can potentially create
+        // a new channel, if our channel doesn't already exist.  That *shouldn't*
+        // happen; if it does, it won't get the right settings.  Set the channel
+        // name in that case to something that has a chance of warning the user,
+        // and that can serve as a signature to diagnose the situation in support.
+        // But really we should fix flutter_local_notifications to not do that
+        // (see issue linked below), or replace that package entirely (#351).
+        '(Zulip internal error)', // TODO never implicitly create channel: https://github.com/MaikuB/flutter_local_notifications/issues/2135
+        tag: _conversationKey(data),
+        color: kZulipBrandColor,
+        icon: 'zulip_notification', // TODO vary for debug
+        // TODO(#128) inbox-style
+      )));
+  }
+
+  static String _conversationKey(MessageFcmMessage data) {
+    final groupKey = _groupKey(data);
+    final conversation = switch (data.recipient) {
+      FcmMessageStreamRecipient(:var streamId, :var topic) => 'stream:$streamId:$topic',
+      FcmMessageDmRecipient(:var allRecipientIds) => 'dm:${allRecipientIds.join(',')}',
+    };
+    return '$groupKey|$conversation';
+  }
+
+  static String _groupKey(FcmMessageWithIdentity data) {
+    // The realm URL can't contain a `|`, because `|` is not a URL code point:
+    //   https://url.spec.whatwg.org/#url-code-points
+    return "${data.realmUri}|${data.userId}";
+  }
+}

macos/Flutter/GeneratedPluginRegistrant.swift

@@ -9,6 +9,7 @@ import device_info_plus
 import file_selector_macos
 import firebase_core
 import firebase_messaging
+import flutter_local_notifications
 import package_info_plus
 import path_provider_foundation
 import share_plus
@@ -20,6 +21,7 @@ func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
   FileSelectorPlugin.register(with: registry.registrar(forPlugin: "FileSelectorPlugin"))
   FLTFirebaseCorePlugin.register(with: registry.registrar(forPlugin: "FLTFirebaseCorePlugin"))
   FLTFirebaseMessagingPlugin.register(with: registry.registrar(forPlugin: "FLTFirebaseMessagingPlugin"))
+  FlutterLocalNotificationsPlugin.register(with: registry.registrar(forPlugin: "FlutterLocalNotificationsPlugin"))
   FPPPackageInfoPlusPlugin.register(with: registry.registrar(forPlugin: "FPPPackageInfoPlusPlugin"))
   PathProviderPlugin.register(with: registry.registrar(forPlugin: "PathProviderPlugin"))
   SharePlusMacosPlugin.register(with: registry.registrar(forPlugin: "SharePlusMacosPlugin"))

macos/Podfile.lock

@@ -36,6 +36,8 @@ PODS:
     - GoogleUtilities/Reachability (~> 7.8)
     - GoogleUtilities/UserDefaults (~> 7.8)
     - nanopb (< 2.30910.0, >= 2.30908.0)
+  - flutter_local_notifications (0.0.1):
+    - FlutterMacOS
   - FlutterMacOS (1.0.0)
   - GoogleDataTransport (9.2.5):
     - GoogleUtilities/Environment (~> 7.7)
@@ -94,6 +96,7 @@ DEPENDENCIES:
   - file_selector_macos (from `Flutter/ephemeral/.symlinks/plugins/file_selector_macos/macos`)
   - firebase_core (from `Flutter/ephemeral/.symlinks/plugins/firebase_core/macos`)
   - firebase_messaging (from `Flutter/ephemeral/.symlinks/plugins/firebase_messaging/macos`)
+  - flutter_local_notifications (from `Flutter/ephemeral/.symlinks/plugins/flutter_local_notifications/macos`)
   - FlutterMacOS (from `Flutter/ephemeral`)
   - package_info_plus (from `Flutter/ephemeral/.symlinks/plugins/package_info_plus/macos`)
   - path_provider_foundation (from `Flutter/ephemeral/.symlinks/plugins/path_provider_foundation/darwin`)
@@ -123,6 +126,8 @@ EXTERNAL SOURCES:
     :path: Flutter/ephemeral/.symlinks/plugins/firebase_core/macos
   firebase_messaging:
     :path: Flutter/ephemeral/.symlinks/plugins/firebase_messaging/macos
+  flutter_local_notifications:
+    :path: Flutter/ephemeral/.symlinks/plugins/flutter_local_notifications/macos
   FlutterMacOS:
     :path: Flutter/ephemeral
   package_info_plus:
@@ -146,6 +151,7 @@ SPEC CHECKSUMS:
   FirebaseCoreInternal: 26233f705cc4531236818a07ac84d20c333e505a
   FirebaseInstallations: b822f91a61f7d1ba763e5ccc9d4f2e6f2ed3b3ee
   FirebaseMessaging: 80b4a086d20ed4fd385a702f4bfa920e14f5064d
+  flutter_local_notifications: 3805ca215b2fb7f397d78b66db91f6a747af52e4
   FlutterMacOS: 8f6f14fa908a6fb3fba0cd85dbd81ec4b251fb24
   GoogleDataTransport: 54dee9d48d14580407f8f5fbf2f496e92437a2f2
   GoogleUtilities: 13e2c67ede716b8741c7989e26893d151b2b2084

pubspec.lock

@@ -249,6 +249,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.3.3"
+  dbus:
+    dependency: transitive
+    description:
+      name: dbus
+      sha256: "6f07cba3f7b3448d42d015bfd3d53fe12e5b36da2423f23838efc1d5fb31a263"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.7.8"
   device_info_plus:
     dependency: "direct main"
     description:
@@ -414,6 +422,30 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.0.0"
+  flutter_local_notifications:
+    dependency: "direct main"
+    description:
+      name: flutter_local_notifications
+      sha256: "6d11ea777496061e583623aaf31923f93a9409ef8fcaeeefdd6cd78bf4fe5bb3"
+      url: "https://pub.dev"
+    source: hosted
+    version: "16.1.0"
+  flutter_local_notifications_linux:
+    dependency: transitive
+    description:
+      name: flutter_local_notifications_linux
+      sha256: "33f741ef47b5f63cc7f78fe75eeeac7e19f171ff3c3df054d84c1e38bedb6a03"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.0.0+1"
+  flutter_local_notifications_platform_interface:
+    dependency: "direct main"
+    description:
+      name: flutter_local_notifications_platform_interface
+      sha256: "7cf643d6d5022f3baed0be777b0662cce5919c0a7b86e700299f22dc4ae660ef"
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.0.0+1"
   flutter_localizations:
     dependency: "direct main"
     description: flutter
@@ -757,6 +789,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.2.1"
+  petitparser:
+    dependency: transitive
+    description:
+      name: petitparser
+      sha256: cb3798bef7fc021ac45b308f4b51208a152792445cce0448c9a4ba5879dd8750
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.4.0"
   platform:
     dependency: transitive
     description:
@@ -994,6 +1034,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.5.9"
+  timezone:
+    dependency: transitive
+    description:
+      name: timezone
+      sha256: "1cfd8ddc2d1cfd836bc93e67b9be88c3adaeca6f40a00ca999104c30693cdca0"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.9.2"
   timing:
     dependency: transitive
     description:
@@ -1154,6 +1202,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.0.3"
+  xml:
+    dependency: transitive
+    description:
+      name: xml
+      sha256: "5bc72e1e45e941d825fd7468b9b4cc3b9327942649aeb6fc5cdbf135f0a86e84"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.3.0"
   yaml:
     dependency: transitive
     description:

pubspec.yaml

@@ -62,6 +62,8 @@ dependencies:
     sdk: flutter
   firebase_messaging: ^14.6.3
   firebase_core: ^2.14.0
+  flutter_local_notifications_platform_interface: ^7.0.0+1
+  flutter_local_notifications: ^16.1.0
 
 dev_dependencies:
   flutter_test: