notif: Concurrently initialize NotificationOpenManager

Move NotificationOpenManager initialization to
NotificationService and wait for future to complete,
while also loading the GlobalStore, displaying a
loading spinner while both of them load concurrently.

This is an optimization where previously the
NotificationOpenManager initialization would happen
sequentially before the GlobalStore load.

Author: rajveermalviya

lib/main.dart

@@ -1,28 +1,20 @@
-import 'dart:async';
-
 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'licenses.dart';
 import 'log.dart';
 import 'model/binding.dart';
-import 'notifications/open.dart';
 import 'notifications/receive.dart';
 import 'widgets/app.dart';
 
-Future<void> main() async {
+void main() {
   assert(() {
     debugLogEnabled = true;
     return true;
   }());
   LicenseRegistry.addLicense(additionalLicenses);
   WidgetsFlutterBinding.ensureInitialized();
   LiveZulipBinding.ensureInitialized();
-
-  // TODO remove this await here
-  // TODO move this initialization to NotificationService.instance.start()
-  await NotificationOpenManager.instance.init();
-
-  unawaited(NotificationService.instance.start());
+  NotificationService.instance.start();
   runApp(const ZulipApp());
 }

lib/notifications/open.dart

@@ -29,20 +29,28 @@ class NotificationOpenManager {
 
   NotificationPayloadForOpen? _notifLaunchData;
 
+  Completer<void>? _intializedSignal;
+  Future<void>? get intializationFuture => _intializedSignal?.future;
+
   Future<void> init() async {
-    switch (defaultTargetPlatform) {
-      case TargetPlatform.iOS:
-      case TargetPlatform.android:
-        _notifLaunchData = await _notifPigeonApi.getNotificationDataFromLaunch();
-        _notifPigeonApi.notificationTapEventsStream()
-          .listen(_navigateForNotification);
-
-      case TargetPlatform.fuchsia:
-      case TargetPlatform.linux:
-      case TargetPlatform.macOS:
-      case TargetPlatform.windows:
-        // Do nothing; we don't offer notifications on these platforms.
-        break;
+    _intializedSignal = Completer();
+    try {
+      switch (defaultTargetPlatform) {
+        case TargetPlatform.iOS:
+        case TargetPlatform.android:
+          _notifLaunchData = await _notifPigeonApi.getNotificationDataFromLaunch();
+          _notifPigeonApi.notificationTapEventsStream()
+            .listen(_navigateForNotification);
+
+        case TargetPlatform.fuchsia:
+        case TargetPlatform.linux:
+        case TargetPlatform.macOS:
+        case TargetPlatform.windows:
+          // Do nothing; we don't offer notifications on these platforms.
+          break;
+      }
+    } finally {
+      _intializedSignal!.complete();
     }
   }
 

lib/notifications/receive.dart

@@ -8,6 +8,7 @@ import '../firebase_options.dart';
 import '../log.dart';
 import '../model/binding.dart';
 import 'display.dart';
+import 'open.dart';
 
 @pragma('vm:entry-point')
 class NotificationService {
@@ -53,6 +54,8 @@ class NotificationService {
   Future<void> start() async {
     switch (defaultTargetPlatform) {
       case TargetPlatform.android:
+        await NotificationOpenManager.instance.init();
+
         await ZulipBinding.instance.firebaseInitializeApp(
           options: kFirebaseOptionsAndroid);
 
@@ -77,6 +80,8 @@ class NotificationService {
         await _getFcmToken();
 
       case TargetPlatform.iOS: // TODO(#324): defer requesting notif permission
+        await NotificationOpenManager.instance.init();
+
         await ZulipBinding.instance.firebaseInitializeApp(
           options: kFirebaseOptionsIos);
 

lib/widgets/app.dart

@@ -202,6 +202,11 @@ class _ZulipAppState extends State<ZulipApp> with WidgetsBindingObserver {
   Widget build(BuildContext context) {
     final themeData = zulipThemeData(context);
     return GlobalStoreWidget(
+      otherAsyncTasks: [
+        if (NotificationOpenManager.instance.intializationFuture
+            case final Future<void> future)
+          future,
+      ],
       child: MaterialApp(
         onGenerateTitle: (BuildContext context) {
           return ZulipLocalizations.of(context).zulipAppTitle;

lib/widgets/store.dart

@@ -9,17 +9,23 @@ import 'page.dart';
 ///
 /// There should be one of this widget, near the root of the tree.
 ///
+/// Shows the [placeholder] widget while concurrently waiting for all
+/// the futures in [otherAsyncTasks] and the global store loading to
+/// finish, and then switches to showing the [child] widget.
+///
 /// See also:
 ///  * [GlobalStoreWidget.of], to get access to the data.
 ///  * [PerAccountStoreWidget], for the user's data associated with a
 ///    particular Zulip account.
 class GlobalStoreWidget extends StatefulWidget {
   const GlobalStoreWidget({
     super.key,
+    this.otherAsyncTasks = const [],
     this.placeholder = const LoadingPlaceholder(),
     required this.child,
   });
 
+  final Iterable<Future<void>> otherAsyncTasks;
   final Widget placeholder;
   final Widget child;
 
@@ -56,24 +62,32 @@ class GlobalStoreWidget extends StatefulWidget {
 }
 
 class _GlobalStoreWidgetState extends State<GlobalStoreWidget> {
+  bool isLoading = true;
   GlobalStore? store;
 
+  Future<void> _loadGlobalStore() async {
+    store = await ZulipBinding.instance.getGlobalStoreUniquely();
+  }
+
   @override
   void initState() {
     super.initState();
-    (() async {
-      final store = await ZulipBinding.instance.getGlobalStoreUniquely();
-      setState(() {
-        this.store = store;
-      });
-    })();
+    () async {
+      try {
+        await Future.wait([
+          _loadGlobalStore(),
+          ...widget.otherAsyncTasks,
+        ]);
+      } finally {
+        if (mounted) setState(() => isLoading = false);
+      }
+    }();
   }
 
   @override
   Widget build(BuildContext context) {
-    final store = this.store;
-    if (store == null) return widget.placeholder;
-    return _GlobalStoreInheritedWidget(store: store, child: widget.child);
+    if (isLoading) return widget.placeholder;
+    return _GlobalStoreInheritedWidget(store: store!, child: widget.child);
   }
 }
 

test/notifications/display_test.dart

@@ -16,7 +16,6 @@ import 'package:zulip/model/localizations.dart';
 import 'package:zulip/model/narrow.dart';
 import 'package:zulip/model/store.dart';
 import 'package:zulip/notifications/display.dart';
-import 'package:zulip/notifications/open.dart';
 import 'package:zulip/notifications/receive.dart';
 import 'package:zulip/widgets/color.dart';
 import 'package:zulip/widgets/theme.dart';
@@ -107,7 +106,6 @@ void main() {
     testBinding.firebaseMessagingInitialToken = '012abc';
     addTearDown(NotificationService.debugReset);
     NotificationService.debugBackgroundIsolateIsLive = false;
-    await NotificationOpenManager.instance.init();
     await NotificationService.instance.start();
   }
 

test/notifications/open_test.dart

@@ -80,7 +80,6 @@ void main() {
     testBinding.firebaseMessagingInitialToken = '012abc';
     addTearDown(NotificationService.debugReset);
     NotificationService.debugBackgroundIsolateIsLive = false;
-    await NotificationOpenManager.instance.init();
     await NotificationService.instance.start();
   }