#6 burst support (samsung camera naming pattern)

lib/model/entry.dart

@@ -4,6 +4,7 @@ import 'package:aves/geo/countries.dart';
 import 'package:aves/model/entry_cache.dart';
 import 'package:aves/model/favourites.dart';
 import 'package:aves/model/metadata.dart';
+import 'package:aves/model/multipage.dart';
 import 'package:aves/model/settings/settings.dart';
 import 'package:aves/model/video/metadata.dart';
 import 'package:aves/ref/mime_types.dart';
@@ -39,6 +40,8 @@ class AvesEntry {
   CatalogMetadata? _catalogMetadata;
   AddressDetails? _addressDetails;
 
+  List<AvesEntry>? burstEntries;
+
   final AChangeNotifier imageChangeNotifier = AChangeNotifier(), metadataChangeNotifier = AChangeNotifier(), addressChangeNotifier = AChangeNotifier();
 
   // TODO TLAD make it dynamic if it depends on OS/lib versions
@@ -64,6 +67,7 @@ class AvesEntry {
     required int? dateModifiedSecs,
     required this.sourceDateTakenMillis,
     required int? durationMillis,
+    this.burstEntries,
   }) {
     this.path = path;
     this.sourceTitle = sourceTitle;
@@ -80,6 +84,7 @@ class AvesEntry {
     String? path,
     int? contentId,
     int? dateModifiedSecs,
+    List<AvesEntry>? burstEntries,
   }) {
     final copyContentId = contentId ?? this.contentId;
     final copied = AvesEntry(
@@ -96,6 +101,7 @@ class AvesEntry {
       dateModifiedSecs: dateModifiedSecs ?? this.dateModifiedSecs,
       sourceDateTakenMillis: sourceDateTakenMillis,
       durationMillis: durationMillis,
+      burstEntries: burstEntries ?? this.burstEntries,
     )
       ..catalogMetadata = _catalogMetadata?.copyWith(contentId: copyContentId)
       ..addressDetails = _addressDetails?.copyWith(contentId: copyContentId);
@@ -228,10 +234,6 @@ class AvesEntry {
 
   bool get is360 => _catalogMetadata?.is360 ?? false;
 
-  bool get isMultiPage => _catalogMetadata?.isMultiPage ?? false;
-
-  bool get isMotionPhoto => isMultiPage && mimeType == MimeTypes.jpeg;
-
   bool get canEdit => path != null;
 
   bool get canRotateAndFlip => canEdit && canEditExif;
@@ -652,6 +654,51 @@ class AvesEntry {
     }
   }
 
+  // multipage
+
+  static final _burstFilenamePattern = RegExp(r'^(\d{8}_\d{6})_(\d+)$');
+
+  bool get isMultiPage => (_catalogMetadata?.isMultiPage ?? false) || isBurst;
+
+  bool get isBurst => burstEntries?.isNotEmpty == true;
+
+  bool get isMotionPhoto => isMultiPage && !isBurst && mimeType == MimeTypes.jpeg;
+
+  String? get burstKey {
+    if (filenameWithoutExtension != null) {
+      final match = _burstFilenamePattern.firstMatch(filenameWithoutExtension!);
+      if (match != null) {
+        return '$directory/${match.group(1)}';
+      }
+    }
+    return null;
+  }
+
+  Future<MultiPageInfo?> getMultiPageInfo() async {
+    if (isBurst) {
+      return MultiPageInfo(
+        mainEntry: this,
+        pages: burstEntries!
+            .mapIndexed((index, entry) => SinglePageInfo(
+                  index: index,
+                  pageId: entry.contentId!,
+                  isDefault: index == 0,
+                  uri: entry.uri,
+                  mimeType: entry.mimeType,
+                  width: entry.width,
+                  height: entry.height,
+                  rotationDegrees: entry.rotationDegrees,
+                  durationMillis: entry.durationMillis,
+                ))
+            .toList(),
+      );
+    } else {
+      return await metadataService.getMultiPageInfo(this);
+    }
+  }
+
+  // sort
+
   // compare by:
   // 1) title ascending
   // 2) extension ascending

lib/model/multipage.dart

@@ -22,6 +22,14 @@ class MultiPageInfo {
         final firstPage = _pages.removeAt(0);
         _pages.insert(0, firstPage.copyWith(isDefault: true));
       }
+
+      final burstEntries = mainEntry.burstEntries;
+      if (burstEntries != null) {
+        _pageEntries.addEntries(pages.map((pageInfo) {
+          final pageEntry = burstEntries.firstWhere((entry) => entry.uri == pageInfo.uri);
+          return MapEntry(pageInfo, pageEntry);
+        }));
+      }
     }
   }
 

lib/model/settings/settings.dart

@@ -212,9 +212,9 @@ class Settings extends ChangeNotifier {
 
   // collection
 
-  EntryGroupFactor get collectionGroupFactor => getEnumOrDefault(collectionGroupFactorKey, EntryGroupFactor.month, EntryGroupFactor.values);
+  EntryGroupFactor get collectionSectionFactor => getEnumOrDefault(collectionGroupFactorKey, EntryGroupFactor.month, EntryGroupFactor.values);
 
-  set collectionGroupFactor(EntryGroupFactor newValue) => setAndNotify(collectionGroupFactorKey, newValue.toString());
+  set collectionSectionFactor(EntryGroupFactor newValue) => setAndNotify(collectionGroupFactorKey, newValue.toString());
 
   EntrySortFactor get collectionSortFactor => getEnumOrDefault(collectionSortFactorKey, EntrySortFactor.date, EntrySortFactor.values);
 

lib/model/source/collection_lens.dart

@@ -13,6 +13,7 @@ import 'package:aves/model/source/location.dart';
 import 'package:aves/model/source/section_keys.dart';
 import 'package:aves/model/source/tag.dart';
 import 'package:aves/utils/change_notifier.dart';
+import 'package:aves/utils/collection_utils.dart';
 import 'package:collection/collection.dart';
 import 'package:flutter/foundation.dart';
 
@@ -21,9 +22,9 @@ import 'enums.dart';
 class CollectionLens with ChangeNotifier {
   final CollectionSource source;
   final Set<CollectionFilter> filters;
-  EntryGroupFactor groupFactor;
+  EntryGroupFactor sectionFactor;
   EntrySortFactor sortFactor;
-  final AChangeNotifier filterChangeNotifier = AChangeNotifier(), sortGroupChangeNotifier = AChangeNotifier();
+  final AChangeNotifier filterChangeNotifier = AChangeNotifier(), sortSectionChangeNotifier = AChangeNotifier();
   final List<StreamSubscription> _subscriptions = [];
   int? id;
   bool listenToSource;
@@ -38,7 +39,7 @@ class CollectionLens with ChangeNotifier {
     this.id,
     this.listenToSource = true,
   })  : filters = (filters ?? {}).whereNotNull().toSet(),
-        groupFactor = settings.collectionGroupFactor,
+        sectionFactor = settings.collectionSectionFactor,
         sortFactor = settings.collectionSortFactor {
     id ??= hashCode;
     if (listenToSource) {
@@ -73,7 +74,7 @@ class CollectionLens with ChangeNotifier {
 
   int get entryCount => _filteredSortedEntries.length;
 
-  // sorted as displayed to the user, i.e. sorted then grouped, not an absolute order on all entries
+  // sorted as displayed to the user, i.e. sorted then sectioned, not an absolute order on all entries
   List<AvesEntry>? _sortedEntries;
 
   List<AvesEntry> get sortedEntries {
@@ -84,9 +85,9 @@ class CollectionLens with ChangeNotifier {
   bool get showHeaders {
     if (sortFactor == EntrySortFactor.size) return false;
 
-    if (sortFactor == EntrySortFactor.date && groupFactor == EntryGroupFactor.none) return false;
+    if (sortFactor == EntrySortFactor.date && sectionFactor == EntryGroupFactor.none) return false;
 
-    final albumSections = sortFactor == EntrySortFactor.name || (sortFactor == EntrySortFactor.date && groupFactor == EntryGroupFactor.album);
+    final albumSections = sortFactor == EntrySortFactor.name || (sortFactor == EntrySortFactor.date && sectionFactor == EntryGroupFactor.album);
     final filterByAlbum = filters.any((f) => f is AlbumFilter);
     if (albumSections && filterByAlbum) return false;
 
@@ -113,9 +114,33 @@ class CollectionLens with ChangeNotifier {
     filterChangeNotifier.notifyListeners();
   }
 
+  final bool groupBursts = true;
+
   void _applyFilters() {
     final entries = source.visibleEntries;
     _filteredSortedEntries = List.of(filters.isEmpty ? entries : entries.where((entry) => filters.every((filter) => filter.test(entry))));
+
+    if (groupBursts) {
+      _groupBursts();
+    }
+  }
+
+  void _groupBursts() {
+    final byBurstKey = groupBy<AvesEntry, String?>(_filteredSortedEntries, (entry) => entry.burstKey).whereNotNullKey();
+    byBurstKey.forEach((burstKey, entries) {
+      if (entries.length > 1) {
+        entries.sort(AvesEntry.compareByName);
+        final mainEntry = entries.first;
+        final burstEntry = mainEntry.copyWith(burstEntries: entries);
+
+        entries.skip(1).toList().forEach((subEntry) {
+          _filteredSortedEntries.remove(subEntry);
+        });
+        final index = _filteredSortedEntries.indexOf(mainEntry);
+        _filteredSortedEntries.removeAt(index);
+        _filteredSortedEntries.insert(index, burstEntry);
+      }
+    });
   }
 
   void _applySort() {
@@ -132,10 +157,10 @@ class CollectionLens with ChangeNotifier {
     }
   }
 
-  void _applyGroup() {
+  void _applySection() {
     switch (sortFactor) {
       case EntrySortFactor.date:
-        switch (groupFactor) {
+        switch (sectionFactor) {
           case EntryGroupFactor.album:
             sections = groupBy<AvesEntry, EntryAlbumSectionKey>(_filteredSortedEntries, (entry) => EntryAlbumSectionKey(entry.directory));
             break;
@@ -168,11 +193,11 @@ class CollectionLens with ChangeNotifier {
   }
 
   // metadata change should also trigger a full refresh
-  // as dates impact sorting and grouping
+  // as dates impact sorting and sectioning
   void _refresh() {
     _applyFilters();
     _applySort();
-    _applyGroup();
+    _applySection();
   }
 
   void _onFavouritesChanged() {
@@ -183,21 +208,21 @@ class CollectionLens with ChangeNotifier {
 
   void _onSettingsChanged() {
     final newSortFactor = settings.collectionSortFactor;
-    final newGroupFactor = settings.collectionGroupFactor;
+    final newSectionFactor = settings.collectionSectionFactor;
 
     final needSort = sortFactor != newSortFactor;
-    final needGroup = needSort || groupFactor != newGroupFactor;
+    final needSection = needSort || sectionFactor != newSectionFactor;
 
     if (needSort) {
       sortFactor = newSortFactor;
       _applySort();
     }
-    if (needGroup) {
+    if (needSection) {
-      groupFactor = newGroupFactor;
+      sectionFactor = newSectionFactor;
-      _applyGroup();
+      _applySection();
     }
-    if (needSort || needGroup) {
+    if (needSort || needSection) {
-      sortGroupChangeNotifier.notifyListeners();
+      sortSectionChangeNotifier.notifyListeners();
     }
   }
 
@@ -206,8 +231,27 @@ class CollectionLens with ChangeNotifier {
   }
 
   void onEntryRemoved(Set<AvesEntry> entries) {
+    if (groupBursts) {
+      // find impacted burst groups
+      final obsoleteBurstEntries = <AvesEntry>{};
+      final burstKeys = entries.map((entry) => entry.burstKey).whereNotNull().toSet();
+      if (burstKeys.isNotEmpty) {
+        _filteredSortedEntries.where((entry) => entry.isBurst && burstKeys.contains(entry.burstKey)).forEach((mainEntry) {
+          final subEntries = mainEntry.burstEntries!;
+          // remove the deleted sub-entries
+          subEntries.removeWhere(entries.contains);
+          if (subEntries.isEmpty) {
+            // remove the burst entry itself
+            obsoleteBurstEntries.add(mainEntry);
+          }
+          // TODO TLAD [burst] recreate the burst main entry if the first sub-entry got deleted
+        });
+        entries.addAll(obsoleteBurstEntries);
+      }
+    }
+
     // we should remove obsolete entries and sections
-    // but do not apply sort/group
+    // but do not apply sort/section
     // as section order change would surprise the user while browsing
     _filteredSortedEntries.removeWhere(entries.contains);
     _sortedEntries?.removeWhere(entries.contains);

lib/services/metadata_service.dart

@@ -105,7 +105,7 @@ class PlatformMetadataService implements MetadataService {
         'uri': entry.uri,
         'sizeBytes': entry.sizeBytes,
       });
-      final pageMaps = (result as List).cast<Map>();
+      final pageMaps = ((result as List?) ?? []).cast<Map>();
       if (entry.isMotionPhoto && pageMaps.isNotEmpty) {
         final imagePage = pageMaps[0];
         imagePage['width'] = entry.width;

lib/widgets/collection/app_bar.dart

@@ -302,7 +302,7 @@ class _CollectionAppBarState extends State<CollectionAppBar> with SingleTickerPr
         final value = await showDialog<EntryGroupFactor>(
           context: context,
           builder: (context) => AvesSelectionDialog<EntryGroupFactor>(
-            initialValue: settings.collectionGroupFactor,
+            initialValue: settings.collectionSectionFactor,
             options: {
               EntryGroupFactor.album: context.l10n.collectionGroupAlbum,
               EntryGroupFactor.month: context.l10n.collectionGroupMonth,
@@ -315,7 +315,7 @@ class _CollectionAppBarState extends State<CollectionAppBar> with SingleTickerPr
         // wait for the dialog to hide as applying the change may block the UI
         await Future.delayed(Durations.dialogTransitionAnimation * timeDilation);
         if (value != null) {
-          settings.collectionGroupFactor = value;
+          settings.collectionSectionFactor = value;
         }
         break;
       case CollectionAction.sort:

lib/widgets/collection/collection_grid.dart

@@ -267,13 +267,13 @@ class _CollectionScrollViewState extends State<_CollectionScrollView> {
 
   void _registerWidget(_CollectionScrollView widget) {
     widget.collection.filterChangeNotifier.addListener(_scrollToTop);
-    widget.collection.sortGroupChangeNotifier.addListener(_scrollToTop);
+    widget.collection.sortSectionChangeNotifier.addListener(_scrollToTop);
     widget.scrollController.addListener(_onScrollChange);
   }
 
   void _unregisterWidget(_CollectionScrollView widget) {
     widget.collection.filterChangeNotifier.removeListener(_scrollToTop);
-    widget.collection.sortGroupChangeNotifier.removeListener(_scrollToTop);
+    widget.collection.sortSectionChangeNotifier.removeListener(_scrollToTop);
     widget.scrollController.removeListener(_onScrollChange);
   }
 

lib/widgets/collection/draggable_thumb_label.dart

@@ -25,7 +25,7 @@ class CollectionDraggableThumbLabel extends StatelessWidget {
       lineBuilder: (context, entry) {
         switch (collection.sortFactor) {
           case EntrySortFactor.date:
-            switch (collection.groupFactor) {
+            switch (collection.sectionFactor) {
               case EntryGroupFactor.album:
                 return [
                   DraggableThumbLabel.formatMonthThumbLabel(context, entry.bestDate),

lib/widgets/collection/entry_set_action_delegate.dart

@@ -8,6 +8,7 @@ import 'package:aves/model/filters/album.dart';
 import 'package:aves/model/highlight.dart';
 import 'package:aves/model/selection.dart';
 import 'package:aves/model/source/collection_lens.dart';
+import 'package:aves/model/source/collection_source.dart';
 import 'package:aves/services/android_app_service.dart';
 import 'package:aves/services/image_op_events.dart';
 import 'package:aves/services/services.dart';
@@ -33,10 +34,7 @@ class EntrySetActionDelegate with FeedbackMixin, PermissionAwareMixin, SizeAware
         _showDeleteDialog(context);
         break;
       case EntryAction.share:
-        final selection = context.read<Selection<AvesEntry>>().selection;
+        _share(context);
-        AndroidAppService.shareEntries(selection).then((success) {
-          if (!success) showNoMatchingAppDialog(context);
-        });
         break;
       default:
         break;
@@ -59,18 +57,31 @@ class EntrySetActionDelegate with FeedbackMixin, PermissionAwareMixin, SizeAware
     }
   }
 
-  void _refreshMetadata(BuildContext context) {
+  Set<AvesEntry> _getExpandedSelectedItems(Selection<AvesEntry> selection) {
-    final collection = context.read<CollectionLens>();
+    return selection.selection.expand((entry) => entry.burstEntries ?? {entry}).toSet();
+  }
+
+  void _share(BuildContext context) {
     final selection = context.read<Selection<AvesEntry>>();
-    collection.source.refreshMetadata(selection.selection);
+    final selectedItems = _getExpandedSelectedItems(selection);
+    AndroidAppService.shareEntries(selectedItems).then((success) {
+      if (!success) showNoMatchingAppDialog(context);
+    });
+  }
+
+  void _refreshMetadata(BuildContext context) {
+    final source = context.read<CollectionSource>();
+    final selection = context.read<Selection<AvesEntry>>();
+    final selectedItems = _getExpandedSelectedItems(selection);
+
+    source.refreshMetadata(selectedItems);
     selection.browse();
   }
 
   Future<void> _moveSelection(BuildContext context, {required MoveType moveType}) async {
-    final collection = context.read<CollectionLens>();
+    final source = context.read<CollectionSource>();
-    final source = collection.source;
     final selection = context.read<Selection<AvesEntry>>();
-    final selectedItems = selection.selection;
+    final selectedItems = _getExpandedSelectedItems(selection);
 
     final selectionDirs = selectedItems.map((e) => e.directory).whereNotNull().toSet();
     if (moveType == MoveType.move) {
@@ -144,6 +155,7 @@ class EntrySetActionDelegate with FeedbackMixin, PermissionAwareMixin, SizeAware
               label: context.l10n.showButtonLabel,
               onPressed: () async {
                 final highlightInfo = context.read<HighlightInfo>();
+                final collection = context.read<CollectionLens>();
                 var targetCollection = collection;
                 if (collection.filters.any((f) => f is AlbumFilter)) {
                   final filter = AlbumFilter(destinationAlbum, source.getAlbumDisplayName(context, destinationAlbum));
@@ -179,10 +191,9 @@ class EntrySetActionDelegate with FeedbackMixin, PermissionAwareMixin, SizeAware
   }
 
   Future<void> _showDeleteDialog(BuildContext context) async {
-    final collection = context.read<CollectionLens>();
+    final source = context.read<CollectionSource>();
-    final source = collection.source;
     final selection = context.read<Selection<AvesEntry>>();
-    final selectedItems = selection.selection;
+    final selectedItems = _getExpandedSelectedItems(selection);
     final selectionDirs = selectedItems.map((e) => e.directory).whereNotNull().toSet();
     final todoCount = selectedItems.length;
 

lib/widgets/collection/grid/headers/any.dart

@@ -36,7 +36,7 @@ class CollectionSectionHeader extends StatelessWidget {
   Widget? _buildHeader(BuildContext context) {
     switch (collection.sortFactor) {
       case EntrySortFactor.date:
-        switch (collection.groupFactor) {
+        switch (collection.sectionFactor) {
           case EntryGroupFactor.album:
             return _buildAlbumHeader(context);
           case EntryGroupFactor.month:

lib/widgets/collection/grid/thumbnail.dart

@@ -76,7 +76,7 @@ class InteractiveThumbnail extends StatelessWidget {
             id: collection.id,
             listenToSource: false,
           );
-          assert(viewerCollection.sortedEntries.contains(entry));
+          assert(viewerCollection.sortedEntries.map((e) => e.contentId).contains(entry.contentId));
           return EntryViewerPage(
             collection: viewerCollection,
             initialEntry: entry,

lib/widgets/collection/thumbnail/decorated.dart

@@ -11,7 +11,7 @@ class DecoratedThumbnail extends StatelessWidget {
   final double tileExtent;
   final CollectionLens? collection;
   final ValueNotifier<bool>? cancellableNotifier;
-  final bool selectable, highlightable;
+  final bool selectable, highlightable, hero;
 
   static final Color borderColor = Colors.grey.shade700;
   static final double borderWidth = AvesBorder.borderWidth;
@@ -24,6 +24,7 @@ class DecoratedThumbnail extends StatelessWidget {
     this.cancellableNotifier,
     this.selectable = true,
     this.highlightable = true,
+    this.hero = true,
   }) : super(key: key);
 
   @override
@@ -33,7 +34,7 @@ class DecoratedThumbnail extends StatelessWidget {
     // hero tag should include a collection identifier, so that it animates
     // between different views of the entry in the same collection (e.g. thumbnails <-> viewer)
     // but not between different collection instances, even with the same attributes (e.g. reloading collection page via drawer)
-    final heroTag = hashValues(collection?.id, entry);
+    final heroTag = hero ? hashValues(collection?.id, entry.uri) : null;
     final isSvg = entry.isSvg;
     Widget child = ThumbnailImage(
       entry: entry,

lib/widgets/collection/thumbnail/overlay.dart

@@ -28,10 +28,10 @@ class ThumbnailEntryOverlay extends StatelessWidget {
         const AnimatedImageIcon()
       else ...[
         if (entry.isRaw && context.select<GridThemeData, bool>((t) => t.showRaw)) const RawIcon(),
-        if (entry.isMultiPage) MultiPageIcon(entry: entry),
         if (entry.isGeotiff) const GeotiffIcon(),
         if (entry.is360) const SphericalImageIcon(),
-      ]
+      ],
+      if (entry.isMultiPage) MultiPageIcon(entry: entry),
     ];
     if (children.isEmpty) return const SizedBox.shrink();
     if (children.length == 1) return children.first;

lib/widgets/common/identity/aves_icons.dart

@@ -112,10 +112,21 @@ class MultiPageIcon extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    IconData icon;
+    String? text;
+    if (entry.isMotionPhoto) {
+      icon = AIcons.motionPhoto;
+    } else {
+      if(entry.isBurst) {
+        text = '${entry.burstEntries?.length}';
+      }
+      icon = AIcons.multiPage;
+    }
     return OverlayIcon(
-      icon: entry.isMotionPhoto ? AIcons.motionPhoto : AIcons.multiPage,
+      icon: icon,
       size: context.select<GridThemeData, double>((t) => t.iconSize),
       iconScale: .8,
+      text: text,
     );
   }
 }

lib/widgets/stats/stats.dart

@@ -28,10 +28,9 @@ class StatsPage extends StatelessWidget {
 
   final CollectionSource source;
   final CollectionLens? parentCollection;
+  late final Set<AvesEntry> entries;
   final Map<String, int> entryCountPerCountry = {}, entryCountPerPlace = {}, entryCountPerTag = {};
 
-  Set<AvesEntry> get entries => parentCollection?.sortedEntries.toSet() ?? source.visibleEntries;
-
   static const mimeDonutMinWidth = 124.0;
 
   StatsPage({
@@ -39,6 +38,7 @@ class StatsPage extends StatelessWidget {
     required this.source,
     this.parentCollection,
   }) : super(key: key) {
+    entries = parentCollection?.sortedEntries.expand((entry) => entry.burstEntries ?? {entry}).toSet() ?? source.visibleEntries;
     entries.forEach((entry) {
       if (entry.hasAddress) {
         final address = entry.addressDetails!;

lib/widgets/viewer/entry_action_delegate.dart

@@ -182,7 +182,7 @@ class EntryActionDelegate with FeedbackMixin, PermissionAwareMixin, SizeAwareMix
 
     final selection = <AvesEntry>{};
     if (entry.isMultiPage) {
-      final multiPageInfo = await metadataService.getMultiPageInfo(entry);
+      final multiPageInfo = await entry.getMultiPageInfo();
       if (multiPageInfo != null) {
         if (entry.isMotionPhoto) {
           await multiPageInfo.extractMotionPhotoVideo();

lib/widgets/viewer/entry_horizontal_pager.dart

@@ -1,9 +1,9 @@
 import 'package:aves/model/entry.dart';
-import 'package:aves/model/multipage.dart';
 import 'package:aves/model/source/collection_lens.dart';
 import 'package:aves/widgets/common/magnifier/pan/gesture_detector_scope.dart';
 import 'package:aves/widgets/common/magnifier/pan/scroll_physics.dart';
 import 'package:aves/widgets/viewer/multipage/conductor.dart';
+import 'package:aves/widgets/viewer/page_entry_builder.dart';
 import 'package:aves/widgets/viewer/visual/entry_page_view.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
@@ -12,7 +12,7 @@ class MultiEntryScroller extends StatefulWidget {
   final CollectionLens collection;
   final PageController pageController;
   final ValueChanged<int> onPageChanged;
-  final void Function(String uri) onViewDisposed;
+  final void Function(AvesEntry mainEntry, AvesEntry? pageEntry) onViewDisposed;
 
   const MultiEntryScroller({
     Key? key,
@@ -44,27 +44,14 @@ class _MultiEntryScrollerState extends State<MultiEntryScroller> with AutomaticK
         physics: const MagnifierScrollerPhysics(parent: BouncingScrollPhysics()),
         onPageChanged: widget.onPageChanged,
         itemBuilder: (context, index) {
-          final entry = entries[index];
+          final mainEntry = entries[index];
 
-          Widget? child;
+          var child = mainEntry.isMultiPage
-          if (entry.isMultiPage) {
+              ? PageEntryBuilder(
-            final multiPageController = context.read<MultiPageConductor>().getController(entry);
+                  multiPageController: context.read<MultiPageConductor>().getController(mainEntry),
-            if (multiPageController != null) {
+                  builder: (pageEntry) => _buildViewer(mainEntry, pageEntry: pageEntry),
-              child = StreamBuilder<MultiPageInfo?>(
+                )
-                stream: multiPageController.infoStream,
+              : _buildViewer(mainEntry);
-                builder: (context, snapshot) {
-                  final multiPageInfo = multiPageController.info;
-                  return ValueListenableBuilder<int?>(
-                    valueListenable: multiPageController.pageNotifier,
-                    builder: (context, page, child) {
-                      return _buildViewer(entry, pageEntry: multiPageInfo?.getPageEntryByIndex(page));
-                    },
-                  );
-                },
-              );
-            }
-          }
-          child ??= _buildViewer(entry);
 
           child = AnimatedBuilder(
             animation: pageController,
@@ -93,17 +80,11 @@ class _MultiEntryScrollerState extends State<MultiEntryScroller> with AutomaticK
   }
 
   Widget _buildViewer(AvesEntry mainEntry, {AvesEntry? pageEntry}) {
-    return Selector<MediaQueryData, Size>(
+    return EntryPageView(
-      selector: (c, mq) => mq.size,
+      key: const Key('imageview'),
-      builder: (c, mqSize, child) {
+      mainEntry: mainEntry,
-        return EntryPageView(
+      pageEntry: pageEntry ?? mainEntry,
-          key: const Key('imageview'),
+      onDisposed: () => widget.onViewDisposed(mainEntry, pageEntry),
-          mainEntry: mainEntry,
-          pageEntry: pageEntry ?? mainEntry,
-          viewportSize: mqSize,
-          onDisposed: () => widget.onViewDisposed(mainEntry.uri),
-        );
-      },
     );
   }
 
@@ -130,25 +111,12 @@ class _SingleEntryScrollerState extends State<SingleEntryScroller> with Automati
   Widget build(BuildContext context) {
     super.build(context);
 
-    Widget? child;
+    var child = mainEntry.isMultiPage
-    if (mainEntry.isMultiPage) {
+        ? PageEntryBuilder(
-      final multiPageController = context.read<MultiPageConductor>().getController(mainEntry);
+            multiPageController: context.read<MultiPageConductor>().getController(mainEntry),
-      if (multiPageController != null) {
+            builder: (pageEntry) => _buildViewer(pageEntry: pageEntry),
-        child = StreamBuilder<MultiPageInfo?>(
+          )
-          stream: multiPageController.infoStream,
+        : _buildViewer();
-          builder: (context, snapshot) {
-            final multiPageInfo = multiPageController.info;
-            return ValueListenableBuilder<int?>(
-              valueListenable: multiPageController.pageNotifier,
-              builder: (context, page, child) {
-                return _buildViewer(pageEntry: multiPageInfo?.getPageEntryByIndex(page));
-              },
-            );
-          },
-        );
-      }
-    }
-    child ??= _buildViewer();
 
     return MagnifierGestureDetectorScope(
       axis: const [Axis.vertical],
@@ -157,15 +125,9 @@ class _SingleEntryScrollerState extends State<SingleEntryScroller> with Automati
   }
 
   Widget _buildViewer({AvesEntry? pageEntry}) {
-    return Selector<MediaQueryData, Size>(
+    return EntryPageView(
-      selector: (c, mq) => mq.size,
+      mainEntry: mainEntry,
-      builder: (c, mqSize, child) {
+      pageEntry: pageEntry ?? mainEntry,
-        return EntryPageView(
-          mainEntry: mainEntry,
-          pageEntry: pageEntry ?? mainEntry,
-          viewportSize: mqSize,
-        );
-      },
     );
   }
 

lib/widgets/viewer/entry_vertical_pager.dart

@@ -18,7 +18,7 @@ class ViewerVerticalPageView extends StatefulWidget {
   final PageController horizontalPager, verticalPager;
   final void Function(int page) onVerticalPageChanged, onHorizontalPageChanged;
   final VoidCallback onImagePageRequested;
-  final void Function(String uri) onViewDisposed;
+  final void Function(AvesEntry mainEntry, AvesEntry? pageEntry) onViewDisposed;
 
   const ViewerVerticalPageView({
     Key? key,

lib/widgets/viewer/entry_viewer_page.dart

@@ -4,6 +4,7 @@ import 'package:aves/widgets/common/providers/media_query_data_provider.dart';
 import 'package:aves/widgets/viewer/entry_viewer_stack.dart';
 import 'package:aves/widgets/viewer/multipage/conductor.dart';
 import 'package:aves/widgets/viewer/video/conductor.dart';
+import 'package:aves/widgets/viewer/visual/conductor.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
@@ -23,15 +24,13 @@ class EntryViewerPage extends StatelessWidget {
   Widget build(BuildContext context) {
     return MediaQueryDataProvider(
       child: Scaffold(
-        body: Provider<VideoConductor>(
+        body: ViewStateConductorProvider(
-          create: (context) => VideoConductor(),
+          child: VideoConductorProvider(
-          dispose: (context, value) => value.dispose(),
+            child: MultiPageConductorProvider(
-          child: Provider<MultiPageConductor>(
+              child: EntryViewerStack(
-            create: (context) => MultiPageConductor(),
+                collection: collection,
-            dispose: (context, value) => value.dispose(),
+                initialEntry: initialEntry,
-            child: EntryViewerStack(
+              ),
-              collection: collection,
-              initialEntry: initialEntry,
             ),
           ),
         ),
@@ -41,3 +40,61 @@ class EntryViewerPage extends StatelessWidget {
     );
   }
 }
+
+class ViewStateConductorProvider extends StatelessWidget {
+  final Widget? child;
+
+  const ViewStateConductorProvider({
+    Key? key,
+    this.child,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return ProxyProvider<MediaQueryData, ViewStateConductor>(
+      create: (context) => ViewStateConductor(),
+      update: (context, mq, value) {
+        value!.viewportSize = mq.size;
+        return value;
+      },
+      dispose: (context, value) => value.dispose(),
+      child: child,
+    );
+  }
+}
+
+class VideoConductorProvider extends StatelessWidget {
+  final Widget? child;
+
+  const VideoConductorProvider({
+    Key? key,
+    this.child,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Provider<VideoConductor>(
+      create: (context) => VideoConductor(),
+      dispose: (context, value) => value.dispose(),
+      child: child,
+    );
+  }
+}
+
+class MultiPageConductorProvider extends StatelessWidget {
+  final Widget? child;
+
+  const MultiPageConductorProvider({
+    Key? key,
+    this.child,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Provider<MultiPageConductor>(
+      create: (context) => MultiPageConductor(),
+      dispose: (context, value) => value.dispose(),
+      child: child,
+    );
+  }
+}

lib/widgets/viewer/entry_viewer_stack.dart

@@ -3,7 +3,6 @@ import 'dart:math';
 import 'package:aves/model/entry.dart';
 import 'package:aves/model/filters/filters.dart';
 import 'package:aves/model/highlight.dart';
-import 'package:aves/model/multipage.dart';
 import 'package:aves/model/settings/enums.dart';
 import 'package:aves/model/settings/settings.dart';
 import 'package:aves/model/source/collection_lens.dart';
@@ -24,17 +23,17 @@ import 'package:aves/widgets/viewer/overlay/bottom/panorama.dart';
 import 'package:aves/widgets/viewer/overlay/bottom/video.dart';
 import 'package:aves/widgets/viewer/overlay/notifications.dart';
 import 'package:aves/widgets/viewer/overlay/top.dart';
+import 'package:aves/widgets/viewer/page_entry_builder.dart';
 import 'package:aves/widgets/viewer/video/conductor.dart';
 import 'package:aves/widgets/viewer/video/controller.dart';
 import 'package:aves/widgets/viewer/video_action_delegate.dart';
-import 'package:aves/widgets/viewer/visual/state.dart';
+import 'package:aves/widgets/viewer/visual/conductor.dart';
 import 'package:collection/collection.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
 import 'package:flutter/services.dart';
 import 'package:provider/provider.dart';
-import 'package:tuple/tuple.dart';
 
 class EntryViewerStack extends StatefulWidget {
   final CollectionLens? collection;
@@ -62,7 +61,6 @@ class _EntryViewerStackState extends State<EntryViewerStack> with FeedbackMixin,
   late Animation<Offset> _bottomOverlayOffset;
   EdgeInsets? _frozenViewInsets, _frozenViewPadding;
   late VideoActionDelegate _videoActionDelegate;
-  final List<Tuple2<String, ValueNotifier<ViewState>>> _viewStateNotifiers = [];
   final Map<MultiPageController, Future<void> Function()> _multiPageControllerPageListeners = {};
   final ValueNotifier<HeroInfo?> _heroInfoNotifier = ValueNotifier(null);
   bool _isEntryTracked = true;
@@ -90,7 +88,11 @@ class _EntryViewerStackState extends State<EntryViewerStack> with FeedbackMixin,
     }
 
     // make sure initial entry is actually among the filtered collection entries
-    final entry = entries.contains(widget.initialEntry) ? widget.initialEntry : entries.firstOrNull;
+    // `initialEntry` may be a dynamic burst entry from another collection lens
+    // so it is, strictly speaking, not contained in the lens used by the viewer,
+    // but it can be found by content ID
+    final initialEntry = widget.initialEntry;
+    final entry = entries.firstWhereOrNull((v) => v.contentId == initialEntry.contentId) ?? entries.firstOrNull;
     // opening hero, with viewer as target
     _heroInfoNotifier.value = HeroInfo(collection?.id, entry);
     _entryNotifier.value = entry;
@@ -169,6 +171,7 @@ class _EntryViewerStackState extends State<EntryViewerStack> with FeedbackMixin,
 
   @override
   Widget build(BuildContext context) {
+    final viewStateConductor = context.read<ViewStateConductor>();
     return WillPopScope(
       onWillPop: () {
         if (_currentVerticalPage.value == infoPage) {
@@ -186,8 +189,6 @@ class _EntryViewerStackState extends State<EntryViewerStack> with FeedbackMixin,
           onNotification: (dynamic notification) {
             if (notification is FilterSelectedNotification) {
               _goToCollection(notification.filter);
-            } else if (notification is ViewStateNotification) {
-              _updateViewState(notification.uri, notification.viewState);
             } else if (notification is EntryDeletedNotification) {
               _onEntryDeleted(context, notification.entry);
             }
@@ -208,7 +209,7 @@ class _EntryViewerStackState extends State<EntryViewerStack> with FeedbackMixin,
                   onVerticalPageChanged: _onVerticalPageChanged,
                   onHorizontalPageChanged: _onHorizontalPageChanged,
                   onImagePageRequested: () => _goToVerticalPage(imagePage),
-                  onViewDisposed: (uri) => _updateViewState(uri, null),
+                  onViewDisposed: (mainEntry, pageEntry) => viewStateConductor.reset(pageEntry ?? mainEntry),
                 ),
                 _buildTopOverlay(),
                 _buildBottomOverlay(),
@@ -221,23 +222,14 @@ class _EntryViewerStackState extends State<EntryViewerStack> with FeedbackMixin,
     );
   }
 
-  void _updateViewState(String uri, ViewState? viewState) {
-    final viewStateNotifier = _viewStateNotifiers.firstWhereOrNull((kv) => kv.item1 == uri)?.item2;
-    viewStateNotifier?.value = viewState ?? ViewState.zero;
-  }
-
   Widget _buildTopOverlay() {
     Widget child = ValueListenableBuilder<AvesEntry?>(
       valueListenable: _entryNotifier,
       builder: (context, mainEntry, child) {
         if (mainEntry == null) return const SizedBox.shrink();
 
-        return NotificationListener<ShowInfoNotification>(
+        Widget _buildContent({AvesEntry? pageEntry}) {
-          onNotification: (notification) {
+          return EmbeddedDataOpener(
-            _goToVerticalPage(infoPage);
-            return true;
-          },
-          child: EmbeddedDataOpener(
             entry: mainEntry,
             child: ViewerTopOverlay(
               mainEntry: mainEntry,
@@ -245,9 +237,21 @@ class _EntryViewerStackState extends State<EntryViewerStack> with FeedbackMixin,
               canToggleFavourite: hasCollection,
               viewInsets: _frozenViewInsets,
               viewPadding: _frozenViewPadding,
-              viewStateNotifier: _viewStateNotifiers.firstWhereOrNull((kv) => kv.item1 == mainEntry.uri)?.item2,
             ),
-          ),
+          );
+        }
+
+        return NotificationListener<ShowInfoNotification>(
+          onNotification: (notification) {
+            _goToVerticalPage(infoPage);
+            return true;
+          },
+          child: mainEntry.isMultiPage
+              ? PageEntryBuilder(
+                  multiPageController: context.read<MultiPageConductor>().getController(mainEntry),
+                  builder: (pageEntry) => _buildContent(pageEntry: pageEntry),
+                )
+              : _buildContent(),
         );
       },
     );
@@ -282,14 +286,17 @@ class _EntryViewerStackState extends State<EntryViewerStack> with FeedbackMixin,
       valueListenable: _entryNotifier,
       builder: (context, mainEntry, child) {
         if (mainEntry == null) return const SizedBox.shrink();
+        final multiPageController = mainEntry.isMultiPage ? context.read<MultiPageConductor>().getController(mainEntry) : null;
 
-        Widget? _buildExtraBottomOverlay(AvesEntry pageEntry) {
+        Widget? _buildExtraBottomOverlay({AvesEntry? pageEntry}) {
+          final targetEntry = pageEntry ?? mainEntry;
+          Widget? child;
           // a 360 video is both a video and a panorama but only the video controls are displayed
-          if (pageEntry.isVideo) {
+          if (targetEntry.isVideo) {
-            return Selector<VideoConductor, AvesVideoController?>(
+            child = Selector<VideoConductor, AvesVideoController?>(
-              selector: (context, vc) => vc.getController(pageEntry),
+              selector: (context, vc) => vc.getController(targetEntry),
               builder: (context, videoController, child) => VideoControlOverlay(
-                entry: pageEntry,
+                entry: targetEntry,
                 controller: videoController,
                 scale: _bottomOverlayScale,
                 onActionSelected: (action) {
@@ -299,40 +306,31 @@ class _EntryViewerStackState extends State<EntryViewerStack> with FeedbackMixin,
                 },
               ),
             );
-          } else if (pageEntry.is360) {
+          } else if (targetEntry.is360) {
-            return PanoramaOverlay(
+            child = PanoramaOverlay(
-              entry: pageEntry,
+              entry: targetEntry,
               scale: _bottomOverlayScale,
             );
           }
-          return null;
+          return child != null
+              ? ExtraBottomOverlay(
+                  viewInsets: _frozenViewInsets,
+                  viewPadding: _frozenViewPadding,
+                  child: child,
+                )
+              : null;
         }
 
-        final multiPageController = mainEntry.isMultiPage ? context.read<MultiPageConductor>().getController(mainEntry) : null;
+        final extraBottomOverlay = mainEntry.isMultiPage
-        final extraBottomOverlay = multiPageController != null
+            ? PageEntryBuilder(
-            ? StreamBuilder<MultiPageInfo?>(
+                multiPageController: multiPageController,
-                stream: multiPageController.infoStream,
+                builder: (pageEntry) => _buildExtraBottomOverlay(pageEntry: pageEntry) ?? const SizedBox(),
-                builder: (context, snapshot) {
+              )
-                  final multiPageInfo = multiPageController.info;
+            : _buildExtraBottomOverlay();
-                  if (multiPageInfo == null) return const SizedBox.shrink();
-                  return ValueListenableBuilder<int?>(
-                    valueListenable: multiPageController.pageNotifier,
-                    builder: (context, page, child) {
-                      final pageEntry = multiPageInfo.getPageEntryByIndex(page);
-                      return _buildExtraBottomOverlay(pageEntry) ?? const SizedBox();
-                    },
-                  );
-                })
-            : _buildExtraBottomOverlay(mainEntry);
 
         return Column(
           children: [
-            if (extraBottomOverlay != null)
+            if (extraBottomOverlay != null) extraBottomOverlay,
-              ExtraBottomOverlay(
-                viewInsets: _frozenViewInsets,
-                viewPadding: _frozenViewPadding,
-                child: extraBottomOverlay,
-              ),
             SlideTransition(
               position: _bottomOverlayOffset,
               child: ViewerBottomOverlay(
@@ -564,7 +562,6 @@ class _EntryViewerStackState extends State<EntryViewerStack> with FeedbackMixin,
   Future<void> _initEntryControllers(AvesEntry? entry) async {
     if (entry == null) return;
 
-    _initViewStateController(entry);
     if (entry.isVideo) {
       await _initVideoController(entry);
     }
@@ -581,20 +578,6 @@ class _EntryViewerStackState extends State<EntryViewerStack> with FeedbackMixin,
     }
   }
 
-  void _initViewStateController(AvesEntry entry) {
-    final uri = entry.uri;
-    var controller = _viewStateNotifiers.firstWhereOrNull((kv) => kv.item1 == uri);
-    if (controller != null) {
-      _viewStateNotifiers.remove(controller);
-    } else {
-      controller = Tuple2(uri, ValueNotifier<ViewState>(ViewState.zero));
-    }
-    _viewStateNotifiers.insert(0, controller);
-    while (_viewStateNotifiers.length > 3) {
-      _viewStateNotifiers.removeLast().item2.dispose();
-    }
-  }
-
   Future<void> _initVideoController(AvesEntry entry) async {
     final controller = context.read<VideoConductor>().getOrCreateController(entry);
     setState(() {});

lib/widgets/viewer/info/info_page.dart

@@ -10,6 +10,8 @@ import 'package:aves/widgets/viewer/info/info_app_bar.dart';
 import 'package:aves/widgets/viewer/info/location_section.dart';
 import 'package:aves/widgets/viewer/info/metadata/metadata_section.dart';
 import 'package:aves/widgets/viewer/info/notifications.dart';
+import 'package:aves/widgets/viewer/multipage/conductor.dart';
+import 'package:aves/widgets/viewer/page_entry_builder.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
@@ -33,9 +35,7 @@ class _InfoPageState extends State<InfoPage> {
   final ScrollController _scrollController = ScrollController();
   bool _scrollStartFromTop = false;
 
-  CollectionLens? get collection => widget.collection;
+  static const splitScreenWidthThreshold = 600;
-
-  AvesEntry? get entry => widget.entryNotifier.value;
 
   @override
   Widget build(BuildContext context) {
@@ -51,20 +51,31 @@ class _InfoPageState extends State<InfoPage> {
                 builder: (c, mqWidth, child) {
                   return ValueListenableBuilder<AvesEntry?>(
                     valueListenable: widget.entryNotifier,
-                    builder: (context, entry, child) {
+                    builder: (context, mainEntry, child) {
-                      return entry != null
+                      if (mainEntry != null) {
-                          ? EmbeddedDataOpener(
+                        Widget _buildContent({AvesEntry? pageEntry}) {
-                              entry: entry,
+                          final targetEntry = pageEntry ?? mainEntry;
-                              child: _InfoPageContent(
+                          return EmbeddedDataOpener(
-                                collection: collection,
+                            entry: targetEntry,
-                                entry: entry,
+                            child: _InfoPageContent(
-                                isScrollingNotifier: widget.isScrollingNotifier,
+                              collection: widget.collection,
-                                scrollController: _scrollController,
+                              entry: targetEntry,
-                                split: mqWidth > 600,
+                              isScrollingNotifier: widget.isScrollingNotifier,
-                                goToViewer: _goToViewer,
+                              scrollController: _scrollController,
-                              ),
+                              split: mqWidth > splitScreenWidthThreshold,
-                            )
+                              goToViewer: _goToViewer,
-                          : const SizedBox.shrink();
+                            ),
+                          );
+                        }
+
+                        return mainEntry.isBurst
+                            ? PageEntryBuilder(
+                                multiPageController: context.read<MultiPageConductor>().getController(mainEntry),
+                                builder: (pageEntry) => _buildContent(pageEntry: pageEntry),
+                              )
+                            : _buildContent();
+                      }
+                      return const SizedBox();
                     },
                   );
                 },

lib/widgets/viewer/multipage/controller.dart

@@ -2,7 +2,6 @@ import 'dart:async';
 
 import 'package:aves/model/entry.dart';
 import 'package:aves/model/multipage.dart';
-import 'package:aves/services/services.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 
@@ -24,9 +23,9 @@ class MultiPageController {
   set page(int? page) => pageNotifier.value = page;
 
   MultiPageController(this.entry) {
-    metadataService.getMultiPageInfo(entry).then((value) {
+    entry.getMultiPageInfo().then((value) {
       if (value == null || _disposed) return;
-      pageNotifier.value = value.defaultPage!.index;
+      pageNotifier.value = value.defaultPage?.index ?? 0;
       _info = value;
       _infoStreamController.add(_info);
     });

lib/widgets/viewer/overlay/bottom/common.dart

@@ -14,6 +14,7 @@ import 'package:aves/widgets/common/fx/blurred.dart';
 import 'package:aves/widgets/viewer/multipage/controller.dart';
 import 'package:aves/widgets/viewer/overlay/bottom/multipage.dart';
 import 'package:aves/widgets/viewer/overlay/common.dart';
+import 'package:aves/widgets/viewer/page_entry_builder.dart';
 import 'package:decorated_icon/decorated_icon.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
@@ -107,30 +108,23 @@ class _ViewerBottomOverlayState extends State<ViewerBottomOverlay> {
                   _lastEntry = entry;
                 }
                 if (_lastEntry == null) return const SizedBox.shrink();
+                final mainEntry = _lastEntry!;
 
-                Widget _buildContent({MultiPageInfo? multiPageInfo, int? page}) => _BottomOverlayContent(
+                Widget _buildContent({AvesEntry? pageEntry}) => _BottomOverlayContent(
-                      mainEntry: _lastEntry!,
+                      mainEntry: mainEntry,
-                      pageEntry: multiPageInfo?.getPageEntryByIndex(page) ?? _lastEntry!,
+                      pageEntry: pageEntry ?? mainEntry,
                       details: _lastDetails,
                       position: widget.showPosition ? '${widget.index + 1}/${widget.entries.length}' : null,
                       availableWidth: availableWidth,
                       multiPageController: multiPageController,
                     );
 
-                if (multiPageController == null) return _buildContent();
+                return multiPageController != null
-
+                    ? PageEntryBuilder(
-                return StreamBuilder<MultiPageInfo?>(
+                        multiPageController: multiPageController!,
-                  stream: multiPageController!.infoStream,
+                        builder: (pageEntry) => _buildContent(pageEntry: pageEntry),
-                  builder: (context, snapshot) {
+                      )
-                    final multiPageInfo = multiPageController!.info;
+                    : _buildContent();
-                    return ValueListenableBuilder<int?>(
-                      valueListenable: multiPageController!.pageNotifier,
-                      builder: (context, page, child) {
-                        return _buildContent(multiPageInfo: multiPageInfo, page: page);
-                      },
-                    );
-                  },
-                );
               },
             ),
           );
@@ -370,7 +364,7 @@ class _PositionTitleRow extends StatelessWidget {
           // but fail to get information about these pages
           final pageCount = multiPageInfo.pageCount;
           if (pageCount > 0) {
-            final page = multiPageInfo.getById(entry.pageId) ?? multiPageInfo.defaultPage;
+            final page = multiPageInfo.getById(entry.pageId ?? entry.contentId) ?? multiPageInfo.defaultPage;
             pagePosition = '${(page?.index ?? 0) + 1}/$pageCount';
           }
         }

lib/widgets/viewer/overlay/bottom/multipage.dart

@@ -5,8 +5,10 @@ import 'package:aves/theme/durations.dart';
 import 'package:aves/widgets/collection/thumbnail/decorated.dart';
 import 'package:aves/widgets/common/grid/theme.dart';
 import 'package:aves/widgets/viewer/multipage/controller.dart';
+import 'package:aves/widgets/viewer/visual/conductor.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
 
 class MultiPageOverlay extends StatefulWidget {
   final MultiPageController controller;
@@ -126,6 +128,7 @@ class _MultiPageOverlayState extends State<MultiPageOverlay> {
                         cancellableNotifier: _cancellableNotifier,
                         selectable: false,
                         highlightable: false,
+                        hero: false,
                       ),
                     ),
                     IgnorePointer(
@@ -148,9 +151,18 @@ class _MultiPageOverlayState extends State<MultiPageOverlay> {
     );
   }
 
+  void _setPage(int newPage) {
+    final oldPage = controller.page;
+    if (oldPage == newPage) return;
+
+    final oldPageEntry = controller.info!.getPageEntryByIndex(oldPage);
+    controller.page = newPage;
+    context.read<ViewStateConductor>().reset(oldPageEntry);
+  }
+
   Future<void> _goToPage(int page) async {
     _syncScroll = false;
-    controller.page = page;
+    _setPage(page);
     await _scrollController.animateTo(
       pageToScrollOffset(page),
       duration: Durations.viewerOverlayPageScrollAnimation,
@@ -161,7 +173,7 @@ class _MultiPageOverlayState extends State<MultiPageOverlay> {
 
   void _onScrollChange() {
     if (_syncScroll) {
-      controller.page = scrollOffsetToPage(_scrollController.offset);
+      _setPage(scrollOffsetToPage(_scrollController.offset));
     }
   }
 

lib/widgets/viewer/overlay/top.dart

@@ -1,7 +1,6 @@
 import 'package:aves/model/actions/entry_actions.dart';
 import 'package:aves/model/entry.dart';
 import 'package:aves/model/favourites.dart';
-import 'package:aves/model/multipage.dart';
 import 'package:aves/model/settings/settings.dart';
 import 'package:aves/theme/durations.dart';
 import 'package:aves/theme/icons.dart';
@@ -12,7 +11,8 @@ import 'package:aves/widgets/viewer/entry_action_delegate.dart';
 import 'package:aves/widgets/viewer/multipage/conductor.dart';
 import 'package:aves/widgets/viewer/overlay/common.dart';
 import 'package:aves/widgets/viewer/overlay/minimap.dart';
-import 'package:aves/widgets/viewer/visual/state.dart';
+import 'package:aves/widgets/viewer/page_entry_builder.dart';
+import 'package:aves/widgets/viewer/visual/conductor.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
@@ -23,7 +23,6 @@ class ViewerTopOverlay extends StatelessWidget {
   final Animation<double> scale;
   final EdgeInsets? viewInsets, viewPadding;
   final bool canToggleFavourite;
-  final ValueNotifier<ViewState>? viewStateNotifier;
 
   static const double outerPadding = 8;
   static const double innerPadding = 8;
@@ -35,7 +34,6 @@ class ViewerTopOverlay extends StatelessWidget {
     required this.canToggleFavourite,
     required this.viewInsets,
     required this.viewPadding,
-    required this.viewStateNotifier,
   }) : super(key: key);
 
   @override
@@ -50,33 +48,19 @@ class ViewerTopOverlay extends StatelessWidget {
             final buttonWidth = OverlayButton.getSize(context);
             final availableCount = ((mqWidth - outerPadding * 2 - buttonWidth) / (buttonWidth + innerPadding)).floor();
 
-            Widget? child;
+            return mainEntry.isMultiPage
-            if (mainEntry.isMultiPage) {
+                ? PageEntryBuilder(
-              final multiPageController = context.read<MultiPageConductor>().getController(mainEntry);
+                    multiPageController: context.read<MultiPageConductor>().getController(mainEntry),
-              if (multiPageController != null) {
+                    builder: (pageEntry) => _buildOverlay(context, availableCount, mainEntry, pageEntry: pageEntry),
-                child = StreamBuilder<MultiPageInfo?>(
+                  )
-                  stream: multiPageController.infoStream,
+                : _buildOverlay(context, availableCount, mainEntry);
-                  builder: (context, snapshot) {
-                    final multiPageInfo = multiPageController.info;
-                    return ValueListenableBuilder<int?>(
-                      valueListenable: multiPageController.pageNotifier,
-                      builder: (context, page, child) {
-                        return _buildOverlay(availableCount, mainEntry, pageEntry: multiPageInfo?.getPageEntryByIndex(page));
-                      },
-                    );
-                  },
-                );
-              }
-            }
-
-            return child ??= _buildOverlay(availableCount, mainEntry);
           },
         ),
       ),
     );
   }
 
-  Widget _buildOverlay(int availableCount, AvesEntry mainEntry, {AvesEntry? pageEntry}) {
+  Widget _buildOverlay(BuildContext context, int availableCount, AvesEntry mainEntry, {AvesEntry? pageEntry}) {
     pageEntry ??= mainEntry;
 
     bool _canDo(EntryAction action) {
@@ -130,22 +114,25 @@ class ViewerTopOverlay extends StatelessWidget {
       },
     );
 
-    return settings.showOverlayMinimap && viewStateNotifier != null
+    if (settings.showOverlayMinimap) {
-        ? Column(
+      final viewStateConductor = context.read<ViewStateConductor>();
-            crossAxisAlignment: CrossAxisAlignment.start,
+      final viewStateNotifier = viewStateConductor.getOrCreateController(pageEntry);
-            children: [
+      return Column(
-              buttonRow,
+        crossAxisAlignment: CrossAxisAlignment.start,
-              const SizedBox(height: 8),
+        children: [
-              FadeTransition(
+          buttonRow,
-                opacity: scale,
+          const SizedBox(height: 8),
-                child: Minimap(
+          FadeTransition(
-                  entry: pageEntry,
+            opacity: scale,
-                  viewStateNotifier: viewStateNotifier!,
+            child: Minimap(
-                ),
+              entry: pageEntry,
-              )
+              viewStateNotifier: viewStateNotifier,
-            ],
+            ),
           )
-        : buttonRow;
+        ],
+      );
+    }
+    return buttonRow;
   }
 }
 
@@ -154,6 +141,8 @@ class _TopOverlayRow extends StatelessWidget {
   final Animation<double> scale;
   final AvesEntry mainEntry, pageEntry;
 
+  AvesEntry get favouriteTargetEntry => mainEntry.isBurst ? pageEntry : mainEntry;
+
   const _TopOverlayRow({
     Key? key,
     required this.quickActions,
@@ -204,7 +193,7 @@ class _TopOverlayRow extends StatelessWidget {
     switch (action) {
       case EntryAction.toggleFavourite:
         child = _FavouriteToggler(
-          entry: mainEntry,
+          entry: favouriteTargetEntry,
           onPressed: onPressed,
         );
         break;
@@ -250,7 +239,7 @@ class _TopOverlayRow extends StatelessWidget {
       // in app actions
       case EntryAction.toggleFavourite:
         child = _FavouriteToggler(
-          entry: mainEntry,
+          entry: favouriteTargetEntry,
           isMenuItem: true,
         );
         break;
@@ -300,7 +289,7 @@ class _TopOverlayRow extends StatelessWidget {
 
   void _onActionSelected(BuildContext context, EntryAction action) {
     var targetEntry = mainEntry;
-    if (mainEntry.isMultiPage && EntryActions.pageActions.contains(action)) {
+    if (mainEntry.isMultiPage && (mainEntry.isBurst || EntryActions.pageActions.contains(action))) {
       final multiPageController = context.read<MultiPageConductor>().getController(mainEntry);
       if (multiPageController != null) {
         final multiPageInfo = multiPageController.info;

lib/widgets/viewer/page_entry_builder.dart

@@ -0,0 +1,35 @@
+import 'package:aves/model/entry.dart';
+import 'package:aves/model/multipage.dart';
+import 'package:aves/widgets/viewer/multipage/controller.dart';
+import 'package:flutter/widgets.dart';
+
+class PageEntryBuilder extends StatelessWidget {
+  final MultiPageController? multiPageController;
+  final Widget Function(AvesEntry? pageEntry) builder;
+
+  const PageEntryBuilder({
+    Key? key,
+    required this.multiPageController,
+    required this.builder,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    final controller = multiPageController;
+    return controller != null
+        ? StreamBuilder<MultiPageInfo?>(
+            stream: controller.infoStream,
+            builder: (context, snapshot) {
+              final multiPageInfo = controller.info;
+              return ValueListenableBuilder<int?>(
+                valueListenable: controller.pageNotifier,
+                builder: (context, page, child) {
+                  final pageEntry = multiPageInfo?.getPageEntryByIndex(page);
+                  return builder(pageEntry);
+                },
+              );
+            },
+          )
+        : builder(null);
+  }
+}

lib/widgets/viewer/printer.dart

@@ -48,7 +48,7 @@ class EntryPrinter with FeedbackMixin {
     }
 
     if (entry.isMultiPage && !entry.isMotionPhoto) {
-      final multiPageInfo = await metadataService.getMultiPageInfo(entry);
+      final multiPageInfo = await entry.getMultiPageInfo();
       if (multiPageInfo != null) {
         final pageCount = multiPageInfo.pageCount;
         if (pageCount > 1) {

lib/widgets/viewer/visual/conductor.dart

@@ -0,0 +1,59 @@
+import 'package:aves/model/entry.dart';
+import 'package:aves/widgets/common/magnifier/scale/scale_boundaries.dart';
+import 'package:aves/widgets/common/magnifier/scale/scale_level.dart';
+import 'package:aves/widgets/viewer/visual/state.dart';
+import 'package:collection/collection.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/rendering.dart';
+import 'package:tuple/tuple.dart';
+
+class ViewStateConductor {
+  final List<Tuple2<String, ValueNotifier<ViewState>>> _controllers = [];
+  Size _viewportSize = Size.zero;
+
+  static const maxControllerCount = 3;
+
+  Future<void> dispose() async {
+    _controllers.clear();
+  }
+
+  set viewportSize(Size size) => _viewportSize = size;
+
+  ValueNotifier<ViewState> getOrCreateController(AvesEntry entry) {
+    var controller = _controllers.firstOrNull;
+    if (controller == null || controller.item1 != entry.uri) {
+      controller = _controllers.firstWhereOrNull((kv) => kv.item1 == entry.uri);
+      if (controller != null) {
+        _controllers.remove(controller);
+      } else {
+        // try to initialize the view state to match magnifier initial state
+        const initialScale = ScaleLevel(ref: ScaleReference.contained);
+        final initialValue = ViewState(
+          Offset.zero,
+          ScaleBoundaries(
+            minScale: initialScale,
+            maxScale: initialScale,
+            initialScale: initialScale,
+            viewportSize: _viewportSize,
+            childSize: entry.displaySize,
+          ).initialScale,
+          _viewportSize,
+        );
+        controller = Tuple2(entry.uri, ValueNotifier<ViewState>(initialValue));
+      }
+      _controllers.insert(0, controller);
+      while (_controllers.length > maxControllerCount) {
+        _controllers.removeLast().item2.dispose();
+      }
+    }
+    return controller.item2;
+  }
+
+  void reset(AvesEntry entry) {
+    final uris = <AvesEntry>{
+      entry,
+      ...?entry.burstEntries,
+    }.map((v) => v.uri).toSet();
+    _controllers.removeWhere((kv) => uris.contains(kv.item1));
+  }
+}

lib/widgets/viewer/visual/entry_page_view.dart

@@ -14,6 +14,7 @@ import 'package:aves/widgets/viewer/hero.dart';
 import 'package:aves/widgets/viewer/overlay/notifications.dart';
 import 'package:aves/widgets/viewer/video/conductor.dart';
 import 'package:aves/widgets/viewer/video/controller.dart';
+import 'package:aves/widgets/viewer/visual/conductor.dart';
 import 'package:aves/widgets/viewer/visual/error.dart';
 import 'package:aves/widgets/viewer/visual/raster.dart';
 import 'package:aves/widgets/viewer/visual/state.dart';
@@ -26,7 +27,6 @@ import 'package:provider/provider.dart';
 
 class EntryPageView extends StatefulWidget {
   final AvesEntry mainEntry, pageEntry;
-  final Size viewportSize;
   final VoidCallback? onDisposed;
 
   static const decorationCheckSize = 20.0;
@@ -35,7 +35,6 @@ class EntryPageView extends StatefulWidget {
     Key? key,
     required this.mainEntry,
     required this.pageEntry,
-    required this.viewportSize,
     this.onDisposed,
   }) : super(key: key);
 
@@ -44,16 +43,14 @@ class EntryPageView extends StatefulWidget {
 }
 
 class _EntryPageViewState extends State<EntryPageView> {
+  late ValueNotifier<ViewState> _viewStateNotifier;
   late MagnifierController _magnifierController;
-  final ValueNotifier<ViewState> _viewStateNotifier = ValueNotifier(ViewState.zero);
   final List<StreamSubscription> _subscriptions = [];
 
   AvesEntry get mainEntry => widget.mainEntry;
 
   AvesEntry get entry => widget.pageEntry;
 
-  Size get viewportSize => widget.viewportSize;
-
   static const initialScale = ScaleLevel(ref: ScaleReference.contained);
   static const minScale = ScaleLevel(ref: ScaleReference.contained);
   static const maxScale = ScaleLevel(factor: 2.0);
@@ -68,9 +65,7 @@ class _EntryPageViewState extends State<EntryPageView> {
   void didUpdateWidget(covariant EntryPageView oldWidget) {
     super.didUpdateWidget(oldWidget);
 
-    if (oldWidget.pageEntry.uri != widget.pageEntry.uri || oldWidget.pageEntry.displaySize != widget.pageEntry.displaySize) {
+    if (oldWidget.pageEntry != widget.pageEntry) {
-      // do not reset the magnifier view state unless main entry or page entry dimensions change,
-      // in effect locking the zoom & position when browsing entry pages of the same size
       _unregisterWidget();
       _registerWidget();
     }
@@ -84,19 +79,7 @@ class _EntryPageViewState extends State<EntryPageView> {
   }
 
   void _registerWidget() {
-    // try to initialize the view state to match magnifier initial state
+    _viewStateNotifier = context.read<ViewStateConductor>().getOrCreateController(entry);
-    _viewStateNotifier.value = ViewState(
-      Offset.zero,
-      ScaleBoundaries(
-        minScale: minScale,
-        maxScale: maxScale,
-        initialScale: initialScale,
-        viewportSize: viewportSize,
-        childSize: entry.displaySize,
-      ).initialScale,
-      viewportSize,
-    );
-
     _magnifierController = MagnifierController();
     _subscriptions.add(_magnifierController.stateStream.listen(_onViewStateChanged));
     _subscriptions.add(_magnifierController.scaleBoundariesStream.listen(_onViewScaleBoundariesChanged));
@@ -134,7 +117,7 @@ class _EntryPageViewState extends State<EntryPageView> {
 
     return Consumer<HeroInfo?>(
       builder: (context, info, child) => Hero(
-        tag: info != null && info.entry == mainEntry ? hashValues(info.collectionId, mainEntry) : hashCode,
+        tag: info != null && info.entry == mainEntry ? hashValues(info.collectionId, mainEntry.uri) : hashCode,
         transitionOnUserGestures: true,
         child: child!,
       ),
@@ -241,7 +224,7 @@ class _EntryPageViewState extends State<EntryPageView> {
   }) {
     return Magnifier(
       // key includes modified date to refresh when the image is modified by metadata (e.g. rotated)
-      key: ValueKey('${entry.pageId}_${entry.dateModifiedSecs}'),
+      key: ValueKey('${entry.uri}_${entry.pageId}_${entry.dateModifiedSecs}'),
       controller: _magnifierController,
       childSize: displaySize ?? entry.displaySize,
       minScale: minScale,
@@ -260,14 +243,12 @@ class _EntryPageViewState extends State<EntryPageView> {
     final current = _viewStateNotifier.value;
     final viewState = ViewState(v.position, v.scale, current.viewportSize);
     _viewStateNotifier.value = viewState;
-    ViewStateNotification(entry.uri, viewState).dispatch(context);
   }
 
   void _onViewScaleBoundariesChanged(ScaleBoundaries v) {
     final current = _viewStateNotifier.value;
     final viewState = ViewState(current.position, current.scale, v.viewportSize);
     _viewStateNotifier.value = viewState;
-    ViewStateNotification(entry.uri, viewState).dispatch(context);
   }
 
   static ScaleState _vectorScaleStateCycle(ScaleState actual) {

lib/widgets/viewer/visual/state.dart

@@ -13,13 +13,3 @@ class ViewState {
   @override
   String toString() => '$runtimeType#${shortHash(this)}{position=$position, scale=$scale, viewportSize=$viewportSize}';
 }
-
-class ViewStateNotification extends Notification {
-  final String uri;
-  final ViewState viewState;
-
-  const ViewStateNotification(this.uri, this.viewState);
-
-  @override
-  String toString() => '$runtimeType#${shortHash(this)}{uri=$uri, viewState=$viewState}';
-}