From 03c4ffb4e5eb69abb4573f07b97bacb8538f8159 Mon Sep 17 00:00:00 2001
From: SergeantPanda <chester.cullen@gmail.com>
Date: Fri, 27 Feb 2026 15:47:09 -0600
Subject: [PATCH] Bug Fix: Applying any filter that temporarily empties the
 channel list (e.g. switching directly between two channel groups, or typing a
 search query that matches nothing) caused the guide to show a blank/empty
 view with no programs visible. The `VariableSizeList` unmounts when
 `filteredChannels` becomes empty, destroying its DOM node and resetting
 `scrollLeft` to 0. On remount the scroll position was never restored because
 `initialScrollComplete` was still `true`. Fixed by saving the user's current
 scroll position when the channel list empties mid-transition, then restoring
 it once new channels have loaded. On first load the guide still scrolls to
 the current time as before.

---
 CHANGELOG.md                 |  1 +
 frontend/src/pages/Guide.jsx | 52 +++++++++++++++++++++++++++++++-----
 2 files changed, 46 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8b3ffbb3..074f6beb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - Channel table onboarding shown when filter returns zero results: The channel store refactor changed to loading only channel IDs instead of full channel objects, leaving `Object.keys(channels).length` always `0` and incorrectly triggering the onboarding state on any empty filter. Fixed by checking `channelIds.length` instead.
+- TV Guide scrolls to position 0 when a filter yields no results: Applying any filter that temporarily empties the channel list (e.g. switching directly between two channel groups, or typing a search query that matches nothing) caused the guide to show a blank/empty view with no programs visible. The `VariableSizeList` unmounts when `filteredChannels` becomes empty, destroying its DOM node and resetting `scrollLeft` to 0. On remount the scroll position was never restored because `initialScrollComplete` was still `true`. Fixed by saving the user's current scroll position when the channel list empties mid-transition, then restoring it once new channels have loaded. On first load the guide still scrolls to the current time as before.
 
 ## [0.20.1] - 2026-02-26
 
diff --git a/frontend/src/pages/Guide.jsx b/frontend/src/pages/Guide.jsx
index c59185f4..310ab78f 100644
--- a/frontend/src/pages/Guide.jsx
+++ b/frontend/src/pages/Guide.jsx
@@ -9,7 +9,7 @@ import React, {
 } from 'react';
 import useChannelsStore from '../store/channels';
 import useLogosStore from '../store/logos';
-import useVideoStore from '../store/useVideoStore'; // NEW import
+import useVideoStore from '../store/useVideoStore';
 import useSettingsStore from '../store/settings';
 import {
   ActionIcon,
@@ -232,7 +232,13 @@ export default function TVChannelGuide({ startDate, endDate }) {
     return () => {
       cancelled = true;
     };
-  }, [channelGroups, searchQuery, selectedGroupId, selectedProfileId]);
+  }, [
+    allowAllGroups,
+    channelGroups,
+    searchQuery,
+    selectedGroupId,
+    selectedProfileId,
+  ]);
 
   // Apply filters when search, group, or profile changes
   const filteredChannels = useMemo(() => {
@@ -609,14 +615,46 @@ export default function TVChannelGuide({ startDate, endDate }) {
     });
   }, []);
 
-  // Scroll to the nearest half-hour mark ONLY on initial load
-  useEffect(() => {
-    if (programs.length > 0 && !initialScrollComplete) {
-      syncScrollLeft(calculateScrollPosition(now, start));
+  // Holds the scroll position to restore after a filter-induced remount.
+  // null means "use the default scroll-to-now on first load".
+  const savedScrollLeftRef = useRef(null);
 
+  // When channels become empty (filter transition unmounts the list), save the
+  // current scroll position so we can restore it once new channels arrive.
+  // Only save if the initial scroll has already happened — otherwise the saved
+  // position would be 0 (the DOM default) and we'd skip the scroll-to-now.
+  useEffect(() => {
+    if (filteredChannels.length === 0) {
+      if (initialScrollComplete) {
+        savedScrollLeftRef.current = guideScrollLeftRef.current;
+      }
+      setInitialScrollComplete(false);
+    }
+  }, [filteredChannels.length, initialScrollComplete]);
+
+  // Scroll on initial load, or restore saved position after a filter transition.
+  // Guard with guideRef.current — the VariableSizeList outer div is null while
+  // unmounted, so we must wait until it remounts before calling syncScrollLeft.
+  useEffect(() => {
+    if (programs.length > 0 && !initialScrollComplete && guideRef.current) {
+      if (savedScrollLeftRef.current !== null) {
+        // Restore where the user was before the filter change
+        syncScrollLeft(savedScrollLeftRef.current);
+        savedScrollLeftRef.current = null;
+      } else {
+        // Genuine first load — scroll to current time
+        syncScrollLeft(calculateScrollPosition(now, start));
+      }
       setInitialScrollComplete(true);
     }
-  }, [programs, start, now, initialScrollComplete, syncScrollLeft]);
+  }, [
+    programs,
+    start,
+    now,
+    initialScrollComplete,
+    syncScrollLeft,
+    filteredChannels.length,
+  ]);
 
   const findChannelByTvgId = useCallback(
     (tvgId) => matchChannelByTvgId(channelIdByTvgId, channelById, tvgId),