feat(mobile): keep search results visible

Search results are replaced with a spinner when loading the next page,
which is quite jarring. Search results now remain visible when loading
the next page with a spinner at the bottom. The next page also loads
sooner, which makes it feel a lot smoother.

mobile/lib/domain/models/search_result.model.dart

@@ -3,30 +3,21 @@ import 'package:immich_mobile/domain/models/asset/base_asset.model.dart';
 
 class SearchResult {
   final List<BaseAsset> assets;
-  final double scrollOffset;
   final int? nextPage;
 
-  const SearchResult({required this.assets, this.scrollOffset = 0.0, this.nextPage});
-
-  SearchResult copyWith({List<BaseAsset>? assets, int? nextPage, double? scrollOffset}) {
-    return SearchResult(
-      assets: assets ?? this.assets,
-      nextPage: nextPage ?? this.nextPage,
-      scrollOffset: scrollOffset ?? this.scrollOffset,
-    );
-  }
+  const SearchResult({required this.assets, this.nextPage});
 
   @override
-  String toString() => 'SearchResult(assets: ${assets.length}, nextPage: $nextPage, scrollOffset: $scrollOffset)';
+  String toString() => 'SearchResult(assets: ${assets.length}, nextPage: $nextPage)';
 
   @override
   bool operator ==(covariant SearchResult other) {
     if (identical(this, other)) return true;
     final listEquals = const DeepCollectionEquality().equals;
 
-    return listEquals(other.assets, assets) && other.nextPage == nextPage && other.scrollOffset == scrollOffset;
+    return listEquals(other.assets, assets) && other.nextPage == nextPage;
   }
 
   @override
-  int get hashCode => assets.hashCode ^ nextPage.hashCode ^ scrollOffset.hashCode;
+  int get hashCode => assets.hashCode ^ nextPage.hashCode;
 }

mobile/lib/domain/services/timeline.service.dart

@@ -78,6 +78,9 @@ class TimelineFactory {
   TimelineService fromAssets(List<BaseAsset> assets, TimelineOrigin type) =>
       TimelineService(_timelineRepository.fromAssets(assets, type));
 
+  TimelineService fromAssetStream(List<BaseAsset> Function() getAssets, Stream<int> assetCount, TimelineOrigin type) =>
+      TimelineService(_timelineRepository.fromAssetStream(getAssets, assetCount, type));
+
   TimelineService fromAssetsWithBuckets(List<BaseAsset> assets, TimelineOrigin type) =>
       TimelineService(_timelineRepository.fromAssetsWithBuckets(assets, type));
 
@@ -112,7 +115,7 @@ class TimelineService {
 
         if (totalAssets == 0) {
           _bufferOffset = 0;
-          _buffer.clear();
+          _buffer = [];
         } else {
           final int offset;
           final int count;

mobile/lib/infrastructure/repositories/timeline.repository.dart

@@ -275,6 +275,19 @@ class DriftTimelineRepository extends DriftDatabaseRepository {
     origin: origin,
   );
 
+  TimelineQuery fromAssetStream(List<BaseAsset> Function() getAssets, Stream<int> assetCount, TimelineOrigin origin) =>
+      (
+        bucketSource: () async* {
+          yield _generateBuckets(getAssets().length);
+          yield* assetCount.map(_generateBuckets);
+        },
+        assetSource: (offset, count) {
+          final assets = getAssets();
+          return Future.value(assets.skip(offset).take(count).toList(growable: false));
+        },
+        origin: origin,
+      );
+
   TimelineQuery fromAssetsWithBuckets(List<BaseAsset> assets, TimelineOrigin origin) {
     // Sort assets by date descending and group by day
     final sorted = List<BaseAsset>.from(assets)..sort((a, b) => b.createdAt.compareTo(a.createdAt));

mobile/lib/presentation/pages/search/drift_search.page.dart

@@ -80,51 +80,28 @@ class DriftSearchPage extends HookConsumerWidget {
     final ratingCurrentFilterWidget = useState<Widget?>(null);
     final displayOptionCurrentFilterWidget = useState<Widget?>(null);
 
-    final isSearching = useState(false);
-
     final userPreferences = ref.watch(userMetadataPreferencesProvider);
 
-    SnackBar searchInfoSnackBar(String message) {
-      return SnackBar(
-        content: Text(message, style: context.textTheme.labelLarge),
-        showCloseIcon: true,
-        behavior: SnackBarBehavior.fixed,
-        closeIconColor: context.colorScheme.onSurface,
-      );
-    }
-
-    searchFilter(SearchFilter filter) async {
-      if (filter.isEmpty) {
-        return;
-      }
-
+    searchFilter(SearchFilter filter) {
       if (preFilter == null && filter == previousFilter.value) {
         return;
       }
 
-      isSearching.value = true;
-      ref.watch(paginatedSearchProvider.notifier).clear();
-      final hasResult = await ref.watch(paginatedSearchProvider.notifier).search(filter);
+      ref.read(paginatedSearchProvider.notifier).clear();
 
-      if (!hasResult) {
-        context.showSnackBar(searchInfoSnackBar('search_no_result'.t(context: context)));
+      if (filter.isEmpty) {
+        previousFilter.value = null;
+        return;
       }
 
+      unawaited(ref.read(paginatedSearchProvider.notifier).search(filter));
       previousFilter.value = filter;
-      isSearching.value = false;
     }
 
     search() => searchFilter(filter.value);
 
-    loadMoreSearchResult() async {
-      isSearching.value = true;
-      final hasResult = await ref.watch(paginatedSearchProvider.notifier).search(filter.value);
-
-      if (!hasResult) {
-        context.showSnackBar(searchInfoSnackBar('search_no_more_result'.t(context: context)));
-      }
-
-      isSearching.value = false;
+    loadMoreSearchResults() {
+      unawaited(ref.read(paginatedSearchProvider.notifier).search(filter.value));
     }
 
     searchPreFilter() {
@@ -742,10 +719,10 @@ class DriftSearchPage extends HookConsumerWidget {
               ),
             ),
           ),
-          if (isSearching.value)
-            const SliverFillRemaining(hasScrollBody: false, child: Center(child: CircularProgressIndicator()))
+          if (filter.value.isEmpty)
+            const _SearchSuggestions()
           else
-            _SearchResultGrid(onScrollEnd: loadMoreSearchResult),
+            _SearchResultGrid(onScrollEnd: loadMoreSearchResults),
         ],
       ),
     );
@@ -757,45 +734,86 @@ class _SearchResultGrid extends ConsumerWidget {
 
   const _SearchResultGrid({required this.onScrollEnd});
 
-  @override
-  Widget build(BuildContext context, WidgetRef ref) {
-    final assets = ref.watch(paginatedSearchProvider.select((s) => s.assets));
+  bool _onScrollUpdateNotification(ScrollNotification notification) {
+    final metrics = notification.metrics;
 
-    if (assets.isEmpty) {
-      return const _SearchEmptyContent();
+    if (metrics.axis != Axis.vertical) return false;
+
+    final isBottomSheet = notification.context?.findAncestorWidgetOfExactType<DraggableScrollableSheet>() != null;
+    final remaining = metrics.maxScrollExtent - metrics.pixels;
+
+    if (remaining < metrics.viewportDimension && !isBottomSheet) {
+      onScrollEnd();
     }
 
-    return NotificationListener<ScrollEndNotification>(
-      onNotification: (notification) {
-        final isBottomSheetNotification =
-            notification.context?.findAncestorWidgetOfExactType<DraggableScrollableSheet>() != null;
+    return false;
+  }
 
-        final metrics = notification.metrics;
-        final isVerticalScroll = metrics.axis == Axis.vertical;
+  Widget? _bottomWidget(BuildContext context, WidgetRef ref) {
+    final isLoading = ref.watch(paginatedSearchProvider.select((s) => s.isLoading));
 
-        if (metrics.pixels >= metrics.maxScrollExtent && isVerticalScroll && !isBottomSheetNotification) {
-          onScrollEnd();
-          ref.read(paginatedSearchProvider.notifier).setScrollOffset(metrics.maxScrollExtent);
-        }
+    if (isLoading) {
+      return const SliverToBoxAdapter(
+        child: Padding(
+          padding: EdgeInsets.symmetric(vertical: 32),
+          child: Center(child: SizedBox.square(dimension: 32, child: CircularProgressIndicator(strokeWidth: 3))),
+        ),
+      );
+    }
 
-        return true;
-      },
+    final hasMore = ref.watch(paginatedSearchProvider.select((s) => s.nextPage != null));
+
+    if (hasMore) return null;
+
+    return SliverToBoxAdapter(
+      child: Padding(
+        padding: const EdgeInsets.symmetric(vertical: 32),
+        child: Center(
+          child: Text(
+            'search_no_more_result'.t(context: context),
+            style: context.textTheme.bodyMedium?.copyWith(color: context.colorScheme.onSurfaceVariant),
+          ),
+        ),
+      ),
+    );
+  }
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final hasAssets = ref.watch(paginatedSearchProvider.select((s) => s.assets.isNotEmpty));
+    final isLoading = ref.watch(paginatedSearchProvider.select((s) => s.isLoading));
+
+    if (!hasAssets) {
+      return isLoading
+          ? const SliverFillRemaining(hasScrollBody: false, child: Center(child: CircularProgressIndicator()))
+          : const _SearchNoResults();
+    }
+
+    return NotificationListener<ScrollUpdateNotification>(
+      onNotification: _onScrollUpdateNotification,
       child: SliverFillRemaining(
         child: ProviderScope(
           overrides: [
             timelineServiceProvider.overrideWith((ref) {
-              final timelineService = ref.watch(timelineFactoryProvider).fromAssets(assets, TimelineOrigin.search);
-              ref.onDispose(timelineService.dispose);
-              return timelineService;
+              final notifier = ref.read(paginatedSearchProvider.notifier);
+              final service = ref
+                  .watch(timelineFactoryProvider)
+                  .fromAssetStream(
+                    () => ref.read(paginatedSearchProvider).assets,
+                    notifier.assetCount,
+                    TimelineOrigin.search,
+                  );
+              ref.onDispose(service.dispose);
+              return service;
             }),
           ],
           child: Timeline(
-            key: ValueKey(assets.length),
             groupBy: GroupAssetsBy.none,
             appBar: null,
             bottomSheet: const GeneralBottomSheet(minChildSize: 0.20),
             snapToMonth: false,
-            initialScrollOffset: ref.read(paginatedSearchProvider.select((s) => s.scrollOffset)),
+            loadingWidget: const SizedBox.shrink(),
+            bottomSliverWidget: _bottomWidget(context, ref),
           ),
         ),
       ),
@@ -803,8 +821,35 @@ class _SearchResultGrid extends ConsumerWidget {
   }
 }
 
-class _SearchEmptyContent extends StatelessWidget {
-  const _SearchEmptyContent();
+class _SearchNoResults extends StatelessWidget {
+  const _SearchNoResults();
+
+  @override
+  Widget build(BuildContext context) {
+    return SliverFillRemaining(
+      hasScrollBody: false,
+      child: Container(
+        alignment: Alignment.center,
+        padding: const EdgeInsets.all(48),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Icon(Icons.search_off_rounded, size: 72, color: context.colorScheme.onSurfaceVariant),
+            const SizedBox(height: 24),
+            Text(
+              'search_no_result'.t(context: context),
+              textAlign: TextAlign.center,
+              style: context.textTheme.bodyLarge?.copyWith(color: context.colorScheme.onSurfaceVariant),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class _SearchSuggestions extends StatelessWidget {
+  const _SearchSuggestions();
 
   @override
   Widget build(BuildContext context) {

mobile/lib/presentation/pages/search/paginated_search.provider.dart

@@ -1,5 +1,7 @@
+import 'dart:async';
+
 import 'package:hooks_riverpod/hooks_riverpod.dart';
-import 'package:immich_mobile/domain/models/search_result.model.dart';
+import 'package:immich_mobile/domain/models/asset/base_asset.model.dart';
 import 'package:immich_mobile/domain/services/search.service.dart';
 import 'package:immich_mobile/models/search/search_filter.model.dart';
 import 'package:immich_mobile/providers/infrastructure/search.provider.dart';
@@ -21,40 +23,52 @@ class SearchFilterProvider extends Notifier<SearchFilter?> {
   }
 }
 
-final paginatedSearchProvider = StateNotifierProvider<PaginatedSearchNotifier, SearchResult>(
+class SearchState {
+  final List<BaseAsset> assets;
+  final int? nextPage;
+  final bool isLoading;
+
+  const SearchState({this.assets = const [], this.nextPage = 1, this.isLoading = false});
+}
+
+final paginatedSearchProvider = StateNotifierProvider<PaginatedSearchNotifier, SearchState>(
   (ref) => PaginatedSearchNotifier(ref.watch(searchServiceProvider)),
 );
 
-class PaginatedSearchNotifier extends StateNotifier<SearchResult> {
+class PaginatedSearchNotifier extends StateNotifier<SearchState> {
   final SearchService _searchService;
+  final _assetCountController = StreamController<int>.broadcast();
 
-  PaginatedSearchNotifier(this._searchService) : super(const SearchResult(assets: [], nextPage: 1));
+  PaginatedSearchNotifier(this._searchService) : super(const SearchState());
 
-  Future<bool> search(SearchFilter filter) async {
-    if (state.nextPage == null) {
-      return false;
-    }
+  Stream<int> get assetCount => _assetCountController.stream;
+
+  Future<void> search(SearchFilter filter) async {
+    if (state.nextPage == null || state.isLoading) return;
+
+    state = SearchState(assets: state.assets, nextPage: state.nextPage, isLoading: true);
 
     final result = await _searchService.search(filter, state.nextPage!);
 
     if (result == null) {
-      return false;
+      state = SearchState(assets: state.assets, nextPage: state.nextPage);
+      return;
     }
 
-    state = SearchResult(
-      assets: [...state.assets, ...result.assets],
-      nextPage: result.nextPage,
-      scrollOffset: state.scrollOffset,
-    );
+    final assets = [...state.assets, ...result.assets];
+    state = SearchState(assets: assets, nextPage: result.nextPage);
 
-    return true;
+    _assetCountController.add(assets.length);
   }
 
-  void setScrollOffset(double offset) {
-    state = state.copyWith(scrollOffset: offset);
+  void clear() {
+    state = const SearchState();
+    _assetCountController.add(0);
   }
 
-  clear() {
-    state = const SearchResult(assets: [], nextPage: 1, scrollOffset: 0.0);
+  @override
+  void dispose() {
+    _assetCountController.close();
+    super.dispose();
   }
 }

mobile/lib/presentation/widgets/timeline/constants.dart

@@ -5,6 +5,7 @@ const Size kTimelineFixedTileExtent = Size.square(256);
 const double kTimelineSpacing = 2.0;
 const int kTimelineColumnCount = 3;
 
+const double kScrubberThumbHeight = 48.0;
 const Duration kTimelineScrubberFadeInDuration = Duration(milliseconds: 300);
 const Duration kTimelineScrubberFadeOutDuration = Duration(milliseconds: 800);
 

mobile/lib/presentation/widgets/timeline/scrubber.widget.dart

@@ -530,12 +530,14 @@ class _CircularThumb extends StatelessWidget {
         elevation: 4.0,
         color: backgroundColor,
         borderRadius: const BorderRadius.only(
-          topLeft: Radius.circular(48.0),
-          bottomLeft: Radius.circular(48.0),
+          topLeft: Radius.circular(kScrubberThumbHeight),
+          bottomLeft: Radius.circular(kScrubberThumbHeight),
           topRight: Radius.circular(4.0),
           bottomRight: Radius.circular(4.0),
         ),
-        child: Container(constraints: BoxConstraints.tight(const Size(48.0 * 0.6, 48.0))),
+        child: Container(
+          constraints: BoxConstraints.tight(const Size(kScrubberThumbHeight * 0.6, kScrubberThumbHeight)),
+        ),
       ),
     );
   }

mobile/lib/presentation/widgets/timeline/timeline.widget.dart

@@ -17,6 +17,7 @@ import 'package:immich_mobile/extensions/asyncvalue_extensions.dart';
 import 'package:immich_mobile/extensions/build_context_extensions.dart';
 import 'package:immich_mobile/presentation/widgets/action_buttons/download_status_floating_button.widget.dart';
 import 'package:immich_mobile/presentation/widgets/bottom_sheet/general_bottom_sheet.widget.dart';
+import 'package:immich_mobile/presentation/widgets/timeline/constants.dart';
 import 'package:immich_mobile/presentation/widgets/timeline/scrubber.widget.dart';
 import 'package:immich_mobile/presentation/widgets/timeline/segment.model.dart';
 import 'package:immich_mobile/presentation/widgets/timeline/timeline.state.dart';
@@ -34,6 +35,7 @@ class Timeline extends StatelessWidget {
     super.key,
     this.topSliverWidget,
     this.topSliverWidgetHeight,
+    this.bottomSliverWidget,
     this.showStorageIndicator = false,
     this.withStack = false,
     this.appBar = const ImmichSliverAppBar(floating: true, pinned: false, snap: false),
@@ -41,13 +43,14 @@ class Timeline extends StatelessWidget {
     this.groupBy,
     this.withScrubber = true,
     this.snapToMonth = true,
-    this.initialScrollOffset,
     this.readOnly = false,
     this.persistentBottomBar = false,
+    this.loadingWidget,
   });
 
   final Widget? topSliverWidget;
   final double? topSliverWidgetHeight;
+  final Widget? bottomSliverWidget;
   final bool showStorageIndicator;
   final Widget? appBar;
   final Widget? bottomSheet;
@@ -55,9 +58,9 @@ class Timeline extends StatelessWidget {
   final GroupAssetsBy? groupBy;
   final bool withScrubber;
   final bool snapToMonth;
-  final double? initialScrollOffset;
   final bool readOnly;
   final bool persistentBottomBar;
+  final Widget? loadingWidget;
 
   @override
   Widget build(BuildContext context) {
@@ -82,13 +85,14 @@ class Timeline extends StatelessWidget {
           child: _SliverTimeline(
             topSliverWidget: topSliverWidget,
             topSliverWidgetHeight: topSliverWidgetHeight,
+            bottomSliverWidget: bottomSliverWidget,
             appBar: appBar,
             bottomSheet: bottomSheet,
             withScrubber: withScrubber,
             persistentBottomBar: persistentBottomBar,
             snapToMonth: snapToMonth,
-            initialScrollOffset: initialScrollOffset,
             maxWidth: constraints.maxWidth,
+            loadingWidget: loadingWidget,
           ),
         ),
       ),
@@ -111,24 +115,26 @@ class _SliverTimeline extends ConsumerStatefulWidget {
   const _SliverTimeline({
     this.topSliverWidget,
     this.topSliverWidgetHeight,
+    this.bottomSliverWidget,
     this.appBar,
     this.bottomSheet,
     this.withScrubber = true,
     this.persistentBottomBar = false,
     this.snapToMonth = true,
-    this.initialScrollOffset,
     this.maxWidth,
+    this.loadingWidget,
   });
 
   final Widget? topSliverWidget;
   final double? topSliverWidgetHeight;
+  final Widget? bottomSliverWidget;
   final Widget? appBar;
   final Widget? bottomSheet;
   final bool withScrubber;
   final bool persistentBottomBar;
   final bool snapToMonth;
-  final double? initialScrollOffset;
   final double? maxWidth;
+  final Widget? loadingWidget;
 
   @override
   ConsumerState createState() => _SliverTimelineState();
@@ -152,10 +158,7 @@ class _SliverTimelineState extends ConsumerState<_SliverTimeline> {
   @override
   void initState() {
     super.initState();
-    _scrollController = ScrollController(
-      initialScrollOffset: widget.initialScrollOffset ?? 0.0,
-      onAttach: _restoreAssetPosition,
-    );
+    _scrollController = ScrollController(onAttach: _restoreAssetPosition);
     _eventSubscription = EventStream.shared.listen(_onEvent);
 
     final currentTilesPerRow = ref.read(settingsProvider).get(Setting.tilesPerRow);
@@ -373,6 +376,7 @@ class _SliverTimelineState extends ConsumerState<_SliverTimeline> {
         }
       },
       child: asyncSegments.widgetWhen(
+        onLoading: widget.loadingWidget != null ? () => widget.loadingWidget! : null,
         onData: (segments) {
           final childCount = (segments.lastOrNull?.lastIndex ?? -1) + 1;
           final double appBarExpandedHeight = widget.appBar != null && widget.appBar is MesmerizingSliverAppBar
@@ -380,12 +384,9 @@ class _SliverTimelineState extends ConsumerState<_SliverTimeline> {
               : 0;
           final topPadding = context.padding.top + (widget.appBar == null ? 0 : kToolbarHeight) + 10;
 
-          const scrubberBottomPadding = 100.0;
           const bottomSheetOpenModifier = 120.0;
-          final bottomPadding =
-              context.padding.bottom +
-              (widget.appBar == null ? 0 : scrubberBottomPadding) +
-              (isMultiSelectEnabled ? bottomSheetOpenModifier : 0);
+          final contentBottomPadding = context.padding.bottom + (isMultiSelectEnabled ? bottomSheetOpenModifier : 0);
+          final scrubberBottomPadding = contentBottomPadding + kScrubberThumbHeight;
 
           final grid = CustomScrollView(
             primary: true,
@@ -408,7 +409,8 @@ class _SliverTimelineState extends ConsumerState<_SliverTimeline> {
                   addRepaintBoundaries: false,
                 ),
               ),
-              SliverPadding(padding: EdgeInsets.only(bottom: bottomPadding)),
+              if (widget.bottomSliverWidget != null) widget.bottomSliverWidget!,
+              SliverPadding(padding: EdgeInsets.only(bottom: contentBottomPadding)),
             ],
           );
 
@@ -419,7 +421,7 @@ class _SliverTimelineState extends ConsumerState<_SliverTimeline> {
               layoutSegments: segments,
               timelineHeight: maxHeight,
               topPadding: topPadding,
-              bottomPadding: bottomPadding,
+              bottomPadding: scrubberBottomPadding,
               monthSegmentSnappingOffset: widget.topSliverWidgetHeight ?? 0 + appBarExpandedHeight,
               hasAppBar: widget.appBar != null,
               child: grid,