From c41896af27cbb62f9f25f227dad60ba292478fc2 Mon Sep 17 00:00:00 2001
From: Calin-Teodor <calin.chitu@8x8.com>
Date: Thu, 14 Nov 2024 15:37:47 +0200
Subject: [PATCH] feat(filmstrip): force visibility for visible remote
 participants when appState changes

---
 modules/UI/videolayout/LargeVideoManager.js |  1 -
 react/features/filmstrip/reducer.ts         | 17 +++++++++++++++--
 react/features/video-quality/subscriber.ts  |  9 +++++++++
 3 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/modules/UI/videolayout/LargeVideoManager.js b/modules/UI/videolayout/LargeVideoManager.js
index 3895e48740df..f140d9be7edd 100644
--- a/modules/UI/videolayout/LargeVideoManager.js
+++ b/modules/UI/videolayout/LargeVideoManager.js
@@ -11,7 +11,6 @@ import { createScreenSharingIssueEvent } from '../../../react/features/analytics
 import { sendAnalytics } from '../../../react/features/analytics/functions';
 import Avatar from '../../../react/features/base/avatar/components/Avatar';
 import theme from '../../../react/features/base/components/themes/participantsPaneTheme.json';
-import { getSsrcRewritingFeatureFlag } from '../../../react/features/base/config/functions.any';
 import i18next from '../../../react/features/base/i18n/i18next';
 import { JitsiTrackEvents } from '../../../react/features/base/lib-jitsi-meet';
 import { VIDEO_TYPE } from '../../../react/features/base/media/constants';
diff --git a/react/features/filmstrip/reducer.ts b/react/features/filmstrip/reducer.ts
index bd718835387d..8f737a00124b 100644
--- a/react/features/filmstrip/reducer.ts
+++ b/react/features/filmstrip/reducer.ts
@@ -1,3 +1,5 @@
+import { Platform } from 'react-native';
+
 import { PARTICIPANT_LEFT } from '../base/participants/actionTypes';
 import ReducerRegistry from '../base/redux/ReducerRegistry';
 
@@ -301,9 +303,20 @@ ReducerRegistry.register<IFilmstripState>(
                 }
             };
         case SET_VISIBLE_REMOTE_PARTICIPANTS: {
-            const { endIndex, startIndex } = action;
+            let { endIndex, startIndex } = action;
             const { remoteParticipants } = state;
-            const visibleRemoteParticipants = new Set(remoteParticipants.slice(startIndex, endIndex + 1));
+            let visibleRemoteParticipants = new Set(remoteParticipants.slice(startIndex, endIndex + 1));
+
+            // RN > 0.73 made us add this:
+            // Hack alert for iOS where we force visible remote participants
+            // _onViewableItemsChanged gets set to >= 1 when appState transitions from background to active.
+            if (navigator.product === 'ReactNative' && Platform.OS === 'ios') {
+                if (remoteParticipants.length > 1 && visibleRemoteParticipants.size >= 1) {
+                    startIndex = 0;
+                    endIndex = remoteParticipants.length;
+                    visibleRemoteParticipants = new Set(remoteParticipants);
+                }
+            }
 
             return {
                 ...state,
diff --git a/react/features/video-quality/subscriber.ts b/react/features/video-quality/subscriber.ts
index 66299d99e951..725a1f55dc9d 100644
--- a/react/features/video-quality/subscriber.ts
+++ b/react/features/video-quality/subscriber.ts
@@ -87,6 +87,15 @@ StateListenerRegistry.register(
         _updateReceiverVideoConstraints(store);
     });
 
+/**
+ * Handles the use case when the reducedUI is enabled.
+ */
+StateListenerRegistry.register(
+    /* selector */ state => state['features/base/responsive-ui'].reducedUI,
+    /* listener */ (reducedUI, store) => {
+        _updateReceiverVideoConstraints(store);
+    });
+
 /**
  * Updates the receiver constraints when the stage participants change.
  */