Move the responsibility of filtering to an album

lib/models/album.dart

@@ -1,8 +1,10 @@
+import 'package:photos/models/filters/gallery_items_filter.dart';
 import 'package:photos/models/photo.dart';
 
 class Album {
   final String name;
   final List<Photo> photos;
+  final GalleryItemsFilter filter;
 
-  Album(this.name, this.photos);
+  Album(this.name, this.photos, this.filter);
 }

lib/models/filters/favorite_items_filter.dart

@@ -0,0 +1,10 @@
+import 'package:photos/favorite_photos_repository.dart';
+import 'package:photos/models/filters/gallery_items_filter.dart';
+import 'package:photos/models/photo.dart';
+
+class FavoriteItemsFilter implements GalleryItemsFilter {
+  @override
+  bool shouldInclude(Photo photo) {
+    return FavoritePhotosRepository.instance.isLiked(photo);
+  }
+}

lib/models/filters/folder_name_filter.dart

@@ -0,0 +1,14 @@
+import 'package:photos/models/filters/gallery_items_filter.dart';
+import 'package:photos/models/photo.dart';
+import 'package:path/path.dart' as path;
+
+class FolderNameFilter implements GalleryItemsFilter {
+  final String folderName;
+
+  FolderNameFilter(this.folderName);
+
+  @override
+  bool shouldInclude(Photo photo) {
+    return path.basename(photo.pathName) == folderName;
+  }
+}

lib/models/filters/important_items_filter.dart

@@ -1,7 +1,7 @@
 import 'dart:io';
 
+import 'package:photos/models/filters/gallery_items_filter.dart';
 import 'package:photos/models/photo.dart';
-import 'package:photos/utils/gallery_items_filter.dart';
 import 'package:path/path.dart';
 
 class ImportantItemsFilter implements GalleryItemsFilter {

lib/ui/album_list_widget.dart

@@ -4,8 +4,10 @@ import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
 import 'package:photos/favorite_photos_repository.dart';
 import 'package:photos/models/album.dart';
+import 'package:photos/models/filters/favorite_items_filter.dart';
+import 'package:photos/models/filters/folder_name_filter.dart';
 import 'package:photos/models/photo.dart';
-import 'package:photos/ui/album_widget.dart';
+import 'package:photos/ui/album_page.dart';
 import 'package:photos/ui/thumbnail_widget.dart';
 import 'package:path/path.dart' as path;
 
@@ -42,7 +44,7 @@ class _AlbumListWidgetState extends State<AlbumListWidget> {
 
   List<Album> _getAlbums(List<Photo> photos) {
     final albumMap = new LinkedHashMap<String, List<Photo>>();
-    final favorites = Album("Favorites", List<Photo>());
+    final favorites = Album("Favorites", List<Photo>(), FavoriteItemsFilter());
     for (Photo photo in photos) {
       final folder = path.basename(photo.pathName);
       if (!albumMap.containsKey(folder)) {
@@ -59,7 +61,8 @@ class _AlbumListWidgetState extends State<AlbumListWidget> {
       albums.add(favorites);
     }
     for (String albumName in albumMap.keys) {
-      albums.add(Album(albumName, albumMap[albumName]));
+      albums.add(
+          Album(albumName, albumMap[albumName], FolderNameFilter(albumName)));
     }
     return albums;
   }

lib/ui/album_page.dart

@@ -1,6 +1,11 @@
+import 'dart:async';
+
 import 'package:flutter/material.dart';
+import 'package:photos/core/event_bus.dart';
+import 'package:photos/events/local_photos_updated_event.dart';
 import 'package:photos/models/album.dart';
 import 'package:photos/models/photo.dart';
+import 'package:photos/photo_repository.dart';
 import 'package:photos/ui/gallery.dart';
 import 'package:photos/ui/gallery_app_bar_widget.dart';
 import 'package:logging/logging.dart';
@@ -17,6 +22,15 @@ class AlbumPage extends StatefulWidget {
 class _AlbumPageState extends State<AlbumPage> {
   final logger = Logger("AlbumPageState");
   Set<Photo> _selectedPhotos = Set<Photo>();
+  StreamSubscription<LocalPhotosUpdatedEvent> _subscription;
+
+  @override
+  void initState() {
+    _subscription = Bus.instance.on<LocalPhotosUpdatedEvent>().listen((event) {
+      setState(() {});
+    });
+    super.initState();
+  }
 
   @override
   Widget build(Object context) {
@@ -29,18 +43,9 @@ class _AlbumPageState extends State<AlbumPage> {
             _selectedPhotos.clear();
           });
         },
-        onPhotosDeleted: (deletedPhotos) {
-          setState(() {
-            for (Photo deletedPhoto in deletedPhotos) {
-              var index = widget.album.photos.indexOf(deletedPhoto);
-              logger.info("Deleting " + index.toString());
-              widget.album.photos.removeAt(index);
-            }
-          });
-        },
       ),
       body: Gallery(
-        widget.album.photos,
+        _getFilteredPhotos(PhotoRepository.instance.photos),
         _selectedPhotos,
         photoSelectionChangeCallback: (Set<Photo> selectedPhotos) {
           setState(() {
@@ -50,4 +55,20 @@ class _AlbumPageState extends State<AlbumPage> {
       ),
     );
   }
+
+  List<Photo> _getFilteredPhotos(List<Photo> unfilteredPhotos) {
+    final List<Photo> filteredPhotos = List<Photo>();
+    for (Photo photo in unfilteredPhotos) {
+      if (widget.album.filter.shouldInclude(photo)) {
+        filteredPhotos.add(photo);
+      }
+    }
+    return filteredPhotos;
+  }
+
+  @override
+  void dispose() {
+    _subscription.cancel();
+    super.dispose();
+  }
 }

lib/ui/gallery_app_bar_widget.dart

@@ -16,10 +16,8 @@ class GalleryAppBarWidget extends StatefulWidget
   final String title;
   final Set<Photo> selectedPhotos;
   final Function() onSelectionClear;
-  final Function(List<Photo>) onPhotosDeleted;
 
-  GalleryAppBarWidget(this.title, this.selectedPhotos,
-      {this.onSelectionClear, this.onPhotosDeleted});
+  GalleryAppBarWidget(this.title, this.selectedPhotos, {this.onSelectionClear});
 
   @override
   _GalleryAppBarWidgetState createState() => _GalleryAppBarWidgetState();
@@ -139,9 +137,6 @@ class _GalleryAppBarWidgetState extends State<GalleryAppBarWidget> {
     }
     Navigator.of(context, rootNavigator: true).pop();
     PhotoRepository.instance.reloadPhotos();
-    if (widget.onPhotosDeleted != null) {
-      widget.onPhotosDeleted(widget.selectedPhotos.toList());
-    }
     _clearSelectedPhotos();
   }
 

lib/ui/home_widget.dart

@@ -6,13 +6,13 @@ import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
 import 'package:photos/core/event_bus.dart';
 import 'package:photos/events/local_photos_updated_event.dart';
+import 'package:photos/models/filters/important_items_filter.dart';
 import 'package:photos/models/photo.dart';
 import 'package:photos/photo_repository.dart';
 import 'package:photos/ui/album_list_widget.dart';
 import 'package:photos/ui/gallery.dart';
 import 'package:photos/ui/gallery_app_bar_widget.dart';
 import 'package:photos/ui/loading_widget.dart';
-import 'package:photos/utils/important_items_filter.dart';
 import 'package:photos/utils/logging_util.dart';
 import 'package:shake/shake.dart';
 import 'package:logging/logging.dart';