notif [nfc]: Introduce NotificationOpenService

And move the notification navigation data parsing utilities to
the new class.

Author: rajveermalviya

lib/notifications/display.dart

@@ -3,23 +3,16 @@ import 'dart:io';
 
 import 'package:collection/collection.dart';
 import 'package:flutter/foundation.dart';
-import 'package:flutter/widgets.dart' hide Notification;
 import 'package:http/http.dart' as http;
 
 import '../api/model/model.dart';
 import '../api/notifications.dart';
-import '../generated/l10n/zulip_localizations.dart';
 import '../host/android_notifications.dart';
 import '../log.dart';
 import '../model/binding.dart';
 import '../model/localizations.dart';
 import '../model/narrow.dart';
-import '../widgets/app.dart';
 import '../widgets/color.dart';
-import '../widgets/dialog.dart';
-import '../widgets/message_list.dart';
-import '../widgets/page.dart';
-import '../widgets/store.dart';
 import '../widgets/theme.dart';
 import 'open.dart';
 
@@ -482,62 +475,6 @@ class NotificationDisplayManager {
 
   static String _personKey(Uri realmUrl, int userId) => "$realmUrl|$userId";
 
-  /// Provides the route and the account ID by parsing the notification URL.
-  ///
-  /// The URL must have been generated using [NotificationOpenPayload.buildUrl]
-  /// while creating the notification.
-  ///
-  /// Returns null and shows an error dialog if the associated account is not
-  /// found in the global store.
-  static AccountRoute<void>? routeForNotification({
-    required BuildContext context,
-    required Uri url,
-  }) {
-    assert(defaultTargetPlatform == TargetPlatform.android);
-
-    final globalStore = GlobalStoreWidget.of(context);
-
-    assert(debugLog('got notif: url: $url'));
-    assert(url.scheme == 'zulip' && url.host == 'notification');
-    final payload = NotificationOpenPayload.parseUrl(url);
-
-    final account = globalStore.accounts.firstWhereOrNull(
-      (account) => account.realmUrl.origin == payload.realmUrl.origin
-                && account.userId == payload.userId);
-    if (account == null) { // TODO(log)
-      final zulipLocalizations = ZulipLocalizations.of(context);
-      showErrorDialog(context: context,
-        title: zulipLocalizations.errorNotificationOpenTitle,
-        message: zulipLocalizations.errorNotificationOpenAccountNotFound);
-      return null;
-    }
-
-    return MessageListPage.buildRoute(
-      accountId: account.id,
-      // TODO(#82): Open at specific message, not just conversation
-      narrow: payload.narrow);
-  }
-
-  /// Navigates to the [MessageListPage] of the specific conversation
-  /// given the `zulip://notification/…` Android intent data URL,
-  /// generated with [NotificationOpenPayload.buildUrl] while creating
-  /// the notification.
-  static Future<void> navigateForNotification(Uri url) async {
-    assert(defaultTargetPlatform == TargetPlatform.android);
-    assert(debugLog('opened notif: url: $url'));
-
-    NavigatorState navigator = await ZulipApp.navigator;
-    final context = navigator.context;
-    assert(context.mounted);
-    if (!context.mounted) return; // TODO(linter): this is impossible as there's no actual async gap, but the use_build_context_synchronously lint doesn't see that
-
-    final route = routeForNotification(context: context, url: url);
-    if (route == null) return; // TODO(log)
-
-    // TODO(nav): Better interact with existing nav stack on notif open
-    unawaited(navigator.push(route));
-  }
-
   static Future<Uint8List?> _fetchBitmap(Uri url) async {
     try {
       // TODO timeout to prevent waiting indefinitely

lib/notifications/open.dart

@@ -1,5 +1,80 @@
+import 'dart:async';
+
+import 'package:collection/collection.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/widgets.dart';
+
 import '../api/model/model.dart';
+import '../generated/l10n/zulip_localizations.dart';
+import '../log.dart';
 import '../model/narrow.dart';
+import '../widgets/app.dart';
+import '../widgets/dialog.dart';
+import '../widgets/message_list.dart';
+import '../widgets/page.dart';
+import '../widgets/store.dart';
+
+/// Responds to the user opening a notification.
+class NotificationOpenService {
+
+  /// Provides the route and the account ID by parsing the notification URL.
+  ///
+  /// The URL must have been generated using [NotificationOpenPayload.buildUrl]
+  /// while creating the notification.
+  ///
+  /// Returns null and shows an error dialog if the associated account is not
+  /// found in the global store.
+  ///
+  /// The context argument should be a descendant of the app's main [Navigator].
+  static AccountRoute<void>? routeForNotification({
+    required BuildContext context,
+    required Uri url,
+  }) {
+    assert(defaultTargetPlatform == TargetPlatform.android);
+
+    final globalStore = GlobalStoreWidget.of(context);
+
+    assert(debugLog('got notif: url: $url'));
+    assert(url.scheme == 'zulip' && url.host == 'notification');
+    final payload = NotificationOpenPayload.parseUrl(url);
+
+    final account = globalStore.accounts.firstWhereOrNull(
+      (account) => account.realmUrl.origin == payload.realmUrl.origin
+                && account.userId == payload.userId);
+    if (account == null) { // TODO(log)
+      final zulipLocalizations = ZulipLocalizations.of(context);
+      showErrorDialog(context: context,
+        title: zulipLocalizations.errorNotificationOpenTitle,
+        message: zulipLocalizations.errorNotificationOpenAccountNotFound);
+      return null;
+    }
+
+    return MessageListPage.buildRoute(
+      accountId: account.id,
+      // TODO(#82): Open at specific message, not just conversation
+      narrow: payload.narrow);
+  }
+
+  /// Navigates to the [MessageListPage] of the specific conversation
+  /// given the `zulip://notification/…` Android intent data URL,
+  /// generated with [NotificationOpenPayload.buildUrl] while creating
+  /// the notification.
+  static Future<void> navigateForNotification(Uri url) async {
+    assert(defaultTargetPlatform == TargetPlatform.android);
+    assert(debugLog('opened notif: url: $url'));
+
+    NavigatorState navigator = await ZulipApp.navigator;
+    final context = navigator.context;
+    assert(context.mounted);
+    if (!context.mounted) return; // TODO(linter): this is impossible as there's no actual async gap, but the use_build_context_synchronously lint doesn't see that
+
+    final route = routeForNotification(context: context, url: url);
+    if (route == null) return; // TODO(log)
+
+    // TODO(nav): Better interact with existing nav stack on notif open
+    unawaited(navigator.push(route));
+  }
+}
 
 /// The information contained in 'zulip://notification/…' internal
 /// Android intent data URL, used for notification-open flow.

lib/widgets/app.dart

@@ -9,7 +9,7 @@ import '../log.dart';
 import '../model/actions.dart';
 import '../model/localizations.dart';
 import '../model/store.dart';
-import '../notifications/display.dart';
+import '../notifications/open.dart';
 import 'about_zulip.dart';
 import 'dialog.dart';
 import 'home.dart';
@@ -176,7 +176,7 @@ class _ZulipAppState extends State<ZulipApp> with WidgetsBindingObserver {
 
     final initialRouteUrl = Uri.tryParse(initialRoute);
     if (initialRouteUrl case Uri(scheme: 'zulip', host: 'notification')) {
-      final route = NotificationDisplayManager.routeForNotification(
+      final route = NotificationOpenService.routeForNotification(
         context: context,
         url: initialRouteUrl);
 
@@ -209,7 +209,7 @@ class _ZulipAppState extends State<ZulipApp> with WidgetsBindingObserver {
         await LoginPage.handleWebAuthUrl(url);
         return true;
       case Uri(scheme: 'zulip', host: 'notification') && var url:
-        await NotificationDisplayManager.navigateForNotification(url);
+        await NotificationOpenService.navigateForNotification(url);
         return true;
     }
     return super.didPushRouteInformation(routeInformation);