From 843497a70849aa2f804695330ffc956777f67dbc Mon Sep 17 00:00:00 2001
From: Ming Ming <nkming2@gmail.com>
Date: Wed, 4 May 2022 01:37:10 +0800
Subject: [PATCH] Streamline code

---
 app/lib/event/native_event.dart               | 8 +++-----
 app/lib/stream_extension.dart                 | 3 +++
 app/lib/use_case/remove.dart                  | 6 ++----
 app/lib/use_case/unshare_file_from_album.dart | 4 ++--
 4 files changed, 10 insertions(+), 11 deletions(-)
 create mode 100644 app/lib/stream_extension.dart

diff --git a/app/lib/event/native_event.dart b/app/lib/event/native_event.dart
index f1069ba4..1fcaa54f 100644
--- a/app/lib/event/native_event.dart
+++ b/app/lib/event/native_event.dart
@@ -2,6 +2,7 @@ import 'dart:async';
 import 'dart:convert';
 
 import 'package:logging/logging.dart';
+import 'package:nc_photos/stream_extension.dart';
 import 'package:nc_photos_plugin/nc_photos_plugin.dart';
 
 class NativeEventListener<T> {
@@ -12,10 +13,7 @@ class NativeEventListener<T> {
       _log.warning("[begin] Already listening");
       return;
     }
-    _subscription = _mappedStream
-        .where((event) => event is T)
-        .cast<T>()
-        .listen(listener);
+    _subscription = _mappedStream.whereType<T>().listen(listener);
   }
 
   void end() {
@@ -28,7 +26,7 @@ class NativeEventListener<T> {
   }
 
   static late final _mappedStream =
-      NativeEvent.stream.where((event) => event is NativeEventObject).map((ev) {
+      NativeEvent.stream.whereType<NativeEventObject>().map((ev) {
     switch (ev.event) {
       case FileExifUpdatedEvent._id:
         return FileExifUpdatedEvent.fromEvent(ev);
diff --git a/app/lib/stream_extension.dart b/app/lib/stream_extension.dart
new file mode 100644
index 00000000..c80a17e6
--- /dev/null
+++ b/app/lib/stream_extension.dart
@@ -0,0 +1,3 @@
+extension StreamExtension on Stream {
+  Stream<U> whereType<U>() => where((event) => event is U).cast<U>();
+}
diff --git a/app/lib/use_case/remove.dart b/app/lib/use_case/remove.dart
index b75e458e..e7cddc3c 100644
--- a/app/lib/use_case/remove.dart
+++ b/app/lib/use_case/remove.dart
@@ -11,6 +11,7 @@ import 'package:nc_photos/entity/album/provider.dart';
 import 'package:nc_photos/entity/file.dart';
 import 'package:nc_photos/event/event.dart';
 import 'package:nc_photos/iterable_extension.dart';
+import 'package:nc_photos/stream_extension.dart';
 import 'package:nc_photos/use_case/list_album.dart';
 import 'package:nc_photos/use_case/list_share.dart';
 import 'package:nc_photos/use_case/remove_from_album.dart';
@@ -54,10 +55,7 @@ class Remove {
   }
 
   Future<void> _cleanUpAlbums(Account account, List<File> removes) async {
-    final albums = await ListAlbum(_c)(account)
-        .where((event) => event is Album)
-        .cast<Album>()
-        .toList();
+    final albums = await ListAlbum(_c)(account).whereType<Album>().toList();
     // figure out which files need to be unshared with whom
     final unshares = <FileServerIdentityComparator, Set<CiString>>{};
     // clean up only make sense for static albums
diff --git a/app/lib/use_case/unshare_file_from_album.dart b/app/lib/use_case/unshare_file_from_album.dart
index c060e05b..04049dc0 100644
--- a/app/lib/use_case/unshare_file_from_album.dart
+++ b/app/lib/use_case/unshare_file_from_album.dart
@@ -8,6 +8,7 @@ import 'package:nc_photos/entity/album/item.dart';
 import 'package:nc_photos/entity/album/provider.dart';
 import 'package:nc_photos/entity/file.dart';
 import 'package:nc_photos/entity/share.dart';
+import 'package:nc_photos/stream_extension.dart';
 import 'package:nc_photos/use_case/list_album.dart';
 import 'package:nc_photos/use_case/list_share.dart';
 import 'package:nc_photos/use_case/remove_share.dart';
@@ -35,8 +36,7 @@ class UnshareFileFromAlbum {
         "[call] Unshare ${files.length} files from album '${album.name}' with ${unshareWith.length} users");
     // list albums with shares identical to any element in [unshareWith]
     final otherAlbums = await ListAlbum(_c)(account)
-        .where((event) => event is Album)
-        .cast<Album>()
+        .whereType<Album>()
         .where((a) =>
             !a.albumFile!.compareServerIdentity(album.albumFile!) &&
             a.provider is AlbumStaticProvider &&