From 7340e423f1e86a1247eaeb3a3b7d8faa474391a3 Mon Sep 17 00:00:00 2001
From: andy840119 <andy840119@gmail.com>
Date: Sun, 8 Nov 2020 15:32:40 +0900
Subject: [PATCH] Handle batch change at single method.

---
 .../Edit/Singers/SingerManager.cs             | 68 ++++++++++++++++---
 1 file changed, 58 insertions(+), 10 deletions(-)

diff --git a/osu.Game.Rulesets.Karaoke/Edit/Singers/SingerManager.cs b/osu.Game.Rulesets.Karaoke/Edit/Singers/SingerManager.cs
index b23ac424c..633c16010 100644
--- a/osu.Game.Rulesets.Karaoke/Edit/Singers/SingerManager.cs
+++ b/osu.Game.Rulesets.Karaoke/Edit/Singers/SingerManager.cs
@@ -11,6 +11,7 @@
 using osu.Game.Rulesets.Karaoke.Beatmaps.Metadatas;
 using osu.Game.Rulesets.Karaoke.Objects;
 using osu.Game.Screens.Edit;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 
@@ -22,6 +23,9 @@ public class SingerManager : Component
 
         public readonly BindableList<Singer> Singers = new BindableList<Singer>();
 
+        [Resolved(CanBeNull = true)]
+        private IEditorChangeHandler changeHandler { get; set; }
+
         [Resolved]
         private EditorBeatmap beatmap { get; set; }
 
@@ -54,22 +58,66 @@ public IEnumerable<MenuItem> CreateSingerContextMenu(List<Lyric> lyrics)
             bool allSingerInLyric(Singer singer) => lyrics.All(lyric => SingerInLyric(singer, lyric));
         }
 
-        public void AddSingerToLyric(Singer singer, Lyric lyric)
+        public void AddSingerToLyric(Singer singer, Lyric lyric) => AddSingersToLyrics(new List<Singer> { singer }, new List<Lyric> { lyric });
+        public void AddSingersToLyrics(List<Singer> singers, List<Lyric> lyrics)
         {
-            if (SingerInLyric(singer, lyric))
-                return;
+            if (!(singers?.Any() ?? false))
+                throw new ArgumentNullException($"{nameof(singers)} cannot be numm or empty.");
+
+            if (!(lyrics?.Any() ?? false))
+                throw new ArgumentNullException($"{nameof(lyrics)} cannot be numm or empty.");
+
+            changeHandler?.BeginChange();
+
+            foreach (var lyric in lyrics)
+            {
+                foreach (var singer in singers)
+                {
+                    addSingerToLyric(singer, lyric);
+                }
+            }
+
+            changeHandler?.EndChange();
 
-            var existSingerList = lyric.Singers?.ToList() ?? new List<int>();
-            existSingerList.Add(singer.ID);
-            lyric.Singers = existSingerList.ToArray();
+            void addSingerToLyric(Singer singer, Lyric lyric)
+            {
+                if (SingerInLyric(singer, lyric))
+                    return;
+
+                var existSingerList = lyric.Singers?.ToList() ?? new List<int>();
+                existSingerList.Add(singer.ID);
+                lyric.Singers = existSingerList.ToArray();
+            }
         }
 
-        public void RemoveSingerToLyric(Singer singer, Lyric lyric)
+        public void RemoveSingerToLyric(Singer singer, Lyric lyric) => RemoveSingersToLyrics(new List<Singer> { singer }, new List<Lyric> { lyric });
+        public void RemoveSingersToLyrics(List<Singer> singers, List<Lyric> lyrics)
         {
-            if (!SingerInLyric(singer, lyric))
-                return;
+            if (!(singers?.Any() ?? false))
+                throw new ArgumentNullException($"{nameof(singers)} cannot be numm or empty.");
 
-            lyric.Singers = lyric.Singers?.Where(x => x != singer.ID).ToArray();
+            if (!(lyrics?.Any() ?? false))
+                throw new ArgumentNullException($"{nameof(lyrics)} cannot be numm or empty.");
+
+            changeHandler?.BeginChange();
+
+            foreach (var lyric in lyrics)
+            {
+                foreach (var singer in singers)
+                {
+                    removeSingerToLyric(singer, lyric);
+                }
+            }
+
+            changeHandler?.EndChange();
+
+            void removeSingerToLyric(Singer singer, Lyric lyric)
+            {
+                if (!SingerInLyric(singer, lyric))
+                    return;
+
+                lyric.Singers = lyric.Singers?.Where(x => x != singer.ID).ToArray();
+            }
         }
 
         public bool SingerInLyric(Singer singer, Lyric lyric)