Introduce favorites

lib/favorite_photos_repository.dart

@@ -0,0 +1,40 @@
+import 'package:photos/models/photo.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+class FavoritePhotosRepository {
+  static final _favoritePhotoIdsKey = "favorite_photo_ids";
+  FavoritePhotosRepository._privateConstructor();
+  static FavoritePhotosRepository instance =
+      FavoritePhotosRepository._privateConstructor();
+
+  SharedPreferences _preferences;
+
+  Future<void> init() async {
+    _preferences = await SharedPreferences.getInstance();
+  }
+
+  bool isLiked(Photo photo) {
+    return _getLiked().contains(photo.generatedId.toString());
+  }
+
+  Future<bool> setLiked(Photo photo, bool isLiked) {
+    final liked = _getLiked();
+    if (isLiked) {
+      liked.add(photo.generatedId.toString());
+    } else {
+      liked.remove(photo.generatedId.toString());
+    }
+    return _preferences
+        .setStringList(_favoritePhotoIdsKey, liked.toList())
+        .then((_) => isLiked);
+  }
+
+  Set<String> _getLiked() {
+    final value = _preferences.getStringList(_favoritePhotoIdsKey);
+    if (value == null) {
+      return Set<String>();
+    } else {
+      return value.toSet();
+    }
+  }
+}

lib/main.dart

@@ -4,6 +4,7 @@ import 'package:flutter/material.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:photos/core/constants.dart';
 import 'package:photos/core/configuration.dart';
+import 'package:photos/favorite_photos_repository.dart';
 import 'package:photos/photo_sync_manager.dart';
 import 'package:photos/ui/home_widget.dart';
 import 'package:sentry/sentry.dart';
@@ -26,6 +27,7 @@ void _main() {
   WidgetsFlutterBinding.ensureInitialized();
 
   Configuration.instance.init();
+  FavoritePhotosRepository.instance.init();
   PhotoSyncManager.instance.sync();
 
   final SentryClient sentry = new SentryClient(dsn: SENTRY_DSN);

lib/ui/album_list_widget.dart

@@ -2,6 +2,7 @@ import 'dart:collection';
 
 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/photo.dart';
 import 'package:photos/ui/album_widget.dart';
@@ -41,14 +42,22 @@ class _AlbumListWidgetState extends State<AlbumListWidget> {
 
   List<Album> _getAlbums(List<Photo> photos) {
     final albumMap = new LinkedHashMap<String, List<Photo>>();
+    final favorites = Album("Favorites", List<Photo>());
     for (Photo photo in photos) {
       final folder = path.basename(photo.pathName);
       if (!albumMap.containsKey(folder)) {
         albumMap[folder] = new List<Photo>();
       }
       albumMap[folder].add(photo);
+
+      if (FavoritePhotosRepository.instance.isLiked(photo)) {
+        favorites.photos.add(photo);
+      }
     }
     List<Album> albums = new List<Album>();
+    if (favorites.photos.isNotEmpty) {
+      albums.add(favorites);
+    }
     for (String albumName in albumMap.keys) {
       albums.add(Album(albumName, albumMap[albumName]));
     }

lib/ui/detail_page.dart

@@ -1,6 +1,8 @@
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
+import 'package:like_button/like_button.dart';
 import 'package:photos/core/cache/lru_map.dart';
+import 'package:photos/favorite_photos_repository.dart';
 import 'package:photos/models/photo.dart';
 import 'package:photos/ui/extents_page_view.dart';
 import 'package:photos/ui/zoomable_image.dart';
@@ -18,7 +20,7 @@ class DetailPage extends StatefulWidget {
 }
 
 class _DetailPageState extends State<DetailPage> {
-  final logger = Logger("DetailPageState");
+  final _logger = Logger("DetailPageState");
   bool _shouldDisableScroll = false;
   List<Photo> _photos;
   int _selectedIndex = 0;
@@ -35,7 +37,7 @@ class _DetailPageState extends State<DetailPage> {
 
   @override
   Widget build(BuildContext context) {
-    logger.info("Opening " +
+    _logger.info("Opening " +
         _photos[_selectedIndex].toString() +
         ". " +
         _selectedIndex.toString() +
@@ -73,8 +75,9 @@ class _DetailPageState extends State<DetailPage> {
       },
       extents: 1,
       onPageChanged: (int index) {
-        logger.info("onPageChanged to " + index.toString());
-        _selectedIndex = index;
+        setState(() {
+          _selectedIndex = index;
+        });
       },
       physics: _shouldDisableScroll
           ? NeverScrollableScrollPhysics()
@@ -87,6 +90,7 @@ class _DetailPageState extends State<DetailPage> {
   AppBar _buildAppBar() {
     return AppBar(
       actions: <Widget>[
+        _getFavoriteButton(),
         IconButton(
           icon: Icon(Icons.share),
           onPressed: () async {
@@ -96,4 +100,14 @@ class _DetailPageState extends State<DetailPage> {
       ],
     );
   }
+
+  Widget _getFavoriteButton() {
+    final photo = _photos[_selectedIndex];
+    return LikeButton(
+      isLiked: FavoritePhotosRepository.instance.isLiked(photo),
+      onTap: (oldValue) {
+        return FavoritePhotosRepository.instance.setLiked(photo, !oldValue);
+      },
+    );
+  }
 }

pubspec.lock

@@ -21,35 +21,28 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.4.1"
+    version: "2.4.0"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.0"
+    version: "1.0.5"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.3"
-  clock:
-    dependency: transitive
-    description:
-      name: clock
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.1"
+    version: "1.1.2"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.14.12"
+    version: "1.14.11"
   connectivity:
     dependency: "direct main"
     description:
@@ -127,13 +120,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.1.1"
-  fake_async:
-    dependency: transitive
-    description:
-      name: fake_async
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -212,6 +198,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "3.0.1"
+  like_button:
+    dependency: "direct main"
+    description:
+      name: like_button
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.2.0"
   local_image_provider:
     dependency: "direct main"
     description:
@@ -253,7 +246,7 @@ packages:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.7.0"
+    version: "1.6.4"
   path_provider:
     dependency: "direct main"
     description:
@@ -281,7 +274,7 @@ packages:
       name: pedantic
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.9.0"
+    version: "1.8.0+1"
   petitparser:
     dependency: transitive
     description:
@@ -324,6 +317,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "3.2.0"
+  quiver:
+    dependency: transitive
+    description:
+      name: quiver
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.5"
   sensors:
     dependency: transitive
     description:
@@ -384,7 +384,7 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.7.0"
+    version: "1.5.5"
   sqflite:
     dependency: "direct main"
     description:
@@ -447,7 +447,7 @@ packages:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.15"
+    version: "0.2.11"
   toast:
     dependency: "direct main"
     description:

pubspec.yaml

@@ -45,6 +45,7 @@ dependencies:
   shake: ^0.1.0
   archive: ^2.0.11
   flutter_email_sender: ^3.0.1
+  like_button: ^0.2.0
 
 dev_dependencies:
   flutter_test: