feat(mobile): lazy loading of assets (#2413)

mobile/lib/shared/models/album.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/cupertino.dart';
+import 'package:immich_mobile/modules/home/ui/asset_grid/asset_grid_data_structure.dart';
 import 'package:immich_mobile/shared/models/asset.dart';
 import 'package:immich_mobile/shared/models/store.dart';
 import 'package:immich_mobile/shared/models/user.dart';
@@ -34,10 +35,10 @@ class Album {
   final IsarLinks<User> sharedUsers = IsarLinks<User>();
   final IsarLinks<Asset> assets = IsarLinks<Asset>();
 
-  List<Asset> _sortedAssets = [];
+  RenderList _renderList = RenderList.empty();
 
   @ignore
-  List<Asset> get sortedAssets => _sortedAssets;
+  RenderList get renderList => _renderList;
 
   @ignore
   bool get isRemote => remoteId != null;
@@ -69,8 +70,14 @@ class Album {
     return name.join(' ');
   }
 
-  Future<void> loadSortedAssets() async {
-    _sortedAssets = await assets.filter().sortByFileCreatedAt().findAll();
+  Stream<void> watchRenderList(GroupAssetsBy groupAssetsBy) async* {
+    final query = assets.filter().sortByFileCreatedAt();
+    _renderList = await RenderList.fromQuery(query, groupAssetsBy);
+    yield _renderList;
+    await for (final _ in query.watchLazy()) {
+      _renderList = await RenderList.fromQuery(query, groupAssetsBy);
+      yield _renderList;
+    }
   }
 
   @override

mobile/lib/shared/models/asset.dart

@@ -225,7 +225,6 @@ class Asset {
         a.isLocal && !isLocal ||
         width == null && a.width != null ||
         height == null && a.height != null ||
-        exifInfo == null && a.exifInfo != null ||
         livePhotoVideoId == null && a.livePhotoVideoId != null ||
         !isRemote && a.isRemote && isFavorite != a.isFavorite ||
         !isRemote && a.isRemote && isArchived != a.isArchived;

mobile/lib/shared/models/exif_info.dart

@@ -114,6 +114,45 @@ class ExifInfo {
         country: country ?? this.country,
         description: description ?? this.description,
       );
+
+  @override
+  bool operator ==(other) {
+    if (other is! ExifInfo) return false;
+    return id == other.id &&
+        fileSize == other.fileSize &&
+        make == other.make &&
+        model == other.model &&
+        lens == other.lens &&
+        f == other.f &&
+        mm == other.mm &&
+        iso == other.iso &&
+        exposureSeconds == other.exposureSeconds &&
+        lat == other.lat &&
+        long == other.long &&
+        city == other.city &&
+        state == other.state &&
+        country == other.country &&
+        description == other.description;
+  }
+
+  @override
+  @ignore
+  int get hashCode =>
+      id.hashCode ^
+      fileSize.hashCode ^
+      make.hashCode ^
+      model.hashCode ^
+      lens.hashCode ^
+      f.hashCode ^
+      mm.hashCode ^
+      iso.hashCode ^
+      exposureSeconds.hashCode ^
+      lat.hashCode ^
+      long.hashCode ^
+      city.hashCode ^
+      state.hashCode ^
+      country.hashCode ^
+      description.hashCode;
 }
 
 double? _exposureTimeToSeconds(String? s) {

mobile/lib/shared/models/store.dart

@@ -35,6 +35,10 @@ class Store {
     return value;
   }
 
+  /// Watches a specific key for changes
+  static Stream<T?> watch<T>(StoreKey<T> key) =>
+      _db.storeValues.watchObject(key.id).map((e) => e?._extract(key));
+
   /// Returns the stored value for the given key (possibly null)
   static T? tryGet<T>(StoreKey<T> key) => _cache[key.id];