Create online heartbeat & clarify user meeting state variables.

client/lib/features/events/data/services/firestore_event_service.dart

@@ -16,6 +16,17 @@ import 'package:rxdart/rxdart.dart';
 class FirestoreEventService {
   static const events = 'events';
 
+  // How far before an event's scheduled time it starts appearing in upcoming
+  // event queries — keeps recently-started events visible in listings.
+  static const Duration _upcomingEventsLookback = Duration(minutes: 15);
+  // Wider lookback used when querying across all communities, to surface
+  // events that started up to an hour ago.
+  static const Duration _allCommunitiesEventsLookback = Duration(hours: 1);
+  // Throttle on the event-participants Firestore stream to avoid processing
+  // a snapshot on every keystroke / write during busy periods.
+  static const Duration _participantStreamSampleTime =
+      Duration(milliseconds: 500);
+
   // final time = await NTP.now();
   // Future to mimic NTP.now()
   Future<DateTime> get currentTimeAsync => Future(() => clockService.now());
@@ -79,8 +90,9 @@ class FirestoreEventService {
           .where('isPublic', isEqualTo: true)
           .where(
             'scheduledTime',
-            isGreaterThan:
-                Timestamp.fromDate(currentTime.subtract(Duration(minutes: 15))),
+            isGreaterThan: Timestamp.fromDate(
+              currentTime.subtract(_upcomingEventsLookback),
+            ),
           )
           .orderBy('scheduledTime');
 
@@ -107,7 +119,7 @@ class FirestoreEventService {
         .where(
           'scheduledTime',
           isGreaterThan:
-              Timestamp.fromDate(currentTime.subtract(Duration(minutes: 15))),
+              Timestamp.fromDate(currentTime.subtract(_upcomingEventsLookback)),
         )
         .orderBy('scheduledTime');
 
@@ -142,8 +154,9 @@ class FirestoreEventService {
           .where('communityId', isEqualTo: communityId)
           .where(
             'scheduledTime',
-            isGreaterThan:
-                Timestamp.fromDate(currentTime.subtract(Duration(hours: 1))),
+            isGreaterThan: Timestamp.fromDate(
+              currentTime.subtract(_allCommunitiesEventsLookback),
+            ),
           )
           .where('isPublic', isEqualTo: true)
           .orderBy('scheduledTime')
@@ -230,7 +243,7 @@ class FirestoreEventService {
                 !snapshot.metadata.hasPendingWrites &&
                 !snapshot.metadata.isFromCache,
           )
-          .sampleTime(Duration(milliseconds: 500))
+          .sampleTime(_participantStreamSampleTime)
           .asyncMap((snapshot) => convertParticipantListAsync(snapshot)),
     );
   }

client/lib/features/events/features/event_page/data/providers/event_page_provider.dart

@@ -18,7 +18,6 @@ import 'package:client/services.dart';
 import 'package:data_models/analytics/analytics_entities.dart';
 import 'package:data_models/events/event.dart';
 import 'package:data_models/community/community_tag.dart';
-import 'package:client/core/localization/localization_helper.dart';
 
 import '../../../../../../core/routing/locations.dart';
 
@@ -54,6 +53,10 @@ Future<bool> verifyAvailableForEvent(Event event) async {
 }
 
 class EventPageProvider with ChangeNotifier {
+  // Short delay to allow Firebase Auth state to propagate before attempting to
+  // register and enter the meeting with a newly created guest account.
+  static const Duration _guestAccountSetupDelay = Duration(seconds: 5);
+
   final EventProvider eventProvider;
   final CommunityProvider communityProvider;
   final NavBarProvider navBarProvider;
@@ -282,7 +285,7 @@ class EventPageProvider with ChangeNotifier {
       password: 'password',
     );
 
-    await Future.delayed(Duration(seconds: 5));
+    await Future.delayed(_guestAccountSetupDelay);
 
     // Register
     await joinEvent(showConfirm: false);
@@ -337,6 +340,7 @@ class EventPageProvider with ChangeNotifier {
         cancelText: appLocalizationService.getLocalization().no,
       ).show();
       if (cancelParticipation) {
+        if (!navigatorState.mounted) return;
         await alertOnError(
           navigatorState.context,
           () => firestoreEventService.removeParticipant(

client/lib/features/events/features/event_page/presentation/views/event_page.dart

@@ -94,6 +94,10 @@ class EventPage extends StatefulWidget {
 }
 
 class EventPageState extends State<EventPage> implements EventPageView {
+  // How long after the scheduled start time the join-event graphic remains
+  // visible, giving participants a window to join a meeting already in progress.
+  static const int _kHoursAfterEventToShow = 2;
+
   EventProvider get _eventProvider => EventProvider.watch(context);
 
   Event get event => _eventProvider.event;
@@ -240,7 +244,8 @@ class EventPageState extends State<EventPage> implements EventPageView {
     final now = clockService.now();
     final beforeMeetingCutoff =
         scheduled.subtract(Duration(minutes: kMinutesBeforeEventToJoin));
-    final afterMeetingCutoff = scheduled.add(Duration(hours: 2));
+    final afterMeetingCutoff =
+        scheduled.add(Duration(hours: _kHoursAfterEventToShow));
 
     return now.isAfter(beforeMeetingCutoff) && now.isBefore(afterMeetingCutoff);
   }
@@ -260,7 +265,7 @@ class EventPageState extends State<EventPage> implements EventPageView {
                   Positioned.fill(
                     child: ProxiedImage(
                       null,
-                      asset: AppAsset('media/background.gif'),
+                      asset: AppAsset.backgroundGif(),
                       fit: BoxFit.cover,
                       loadingColor: Colors.transparent,
                     ),