From 1a5fc2bbe2a729eb499340223854317c7ddcf9ac Mon Sep 17 00:00:00 2001
From: Ming Ming <nkming2@gmail.com>
Date: Fri, 9 Jul 2021 02:35:32 +0800
Subject: [PATCH] Use stable sort for album

---
 lib/entity/album/sort_provider.dart | 2 +-
 lib/iterable_extension.dart         | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/entity/album/sort_provider.dart b/lib/entity/album/sort_provider.dart
index 6ccba036..ddc56ef1 100644
--- a/lib/entity/album/sort_provider.dart
+++ b/lib/entity/album/sort_provider.dart
@@ -137,7 +137,7 @@ class AlbumTimeSortProvider extends AlbumReversibleSortProvider {
           return Tuple2(
               prevFileTime ?? DateTime.fromMillisecondsSinceEpoch(0), e);
         })
-        .sorted((x, y) {
+        .stableSorted((x, y) {
           if (isAscending) {
             return x.item1.compareTo(y.item1);
           } else {
diff --git a/lib/iterable_extension.dart b/lib/iterable_extension.dart
index 09cb68c5..f6b0c91e 100644
--- a/lib/iterable_extension.dart
+++ b/lib/iterable_extension.dart
@@ -1,9 +1,17 @@
+import 'package:flutter/foundation.dart';
 import 'package:tuple/tuple.dart';
 
 extension IterableExtension<T> on Iterable<T> {
   /// Return a new sorted list
   List<T> sorted([int compare(T a, T b)]) => this.toList()..sort(compare);
 
+  /// Return a new stable sorted list
+  List<T> stableSorted([int compare(T a, T b)]) {
+    final tmp = this.toList();
+    mergeSort(tmp, compare: compare);
+    return tmp;
+  }
+
   /// Return a string representation of this iterable by joining the result of
   /// toString for each items
   String toReadableString() => "[${join(', ')}]";