From 303cc62ee7c8eec32cb9cd4522202bb3cbdf512d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Wed, 6 Jan 2021 21:57:54 +0100
Subject: [PATCH] Transfer flags indicating if settings were changed

---
 .../Mods/CatchModDifficultyAdjust.cs           |  4 ++--
 .../Mods/OsuModDifficultyAdjust.cs             |  4 ++--
 osu.Game/Rulesets/Mods/ModDifficultyAdjust.cs  | 18 +++++++++++++++---
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/osu.Game.Rulesets.Catch/Mods/CatchModDifficultyAdjust.cs b/osu.Game.Rulesets.Catch/Mods/CatchModDifficultyAdjust.cs
index acdd0a420c..438d17dbc5 100644
--- a/osu.Game.Rulesets.Catch/Mods/CatchModDifficultyAdjust.cs
+++ b/osu.Game.Rulesets.Catch/Mods/CatchModDifficultyAdjust.cs
@@ -59,8 +59,8 @@ namespace osu.Game.Rulesets.Catch.Mods
         {
             base.ApplySettings(difficulty);
 
-            difficulty.CircleSize = CircleSize.Value;
-            difficulty.ApproachRate = ApproachRate.Value;
+            ApplySetting(CircleSize, cs => difficulty.CircleSize = cs);
+            ApplySetting(ApproachRate, ar => difficulty.ApproachRate = ar);
         }
     }
 }
diff --git a/osu.Game.Rulesets.Osu/Mods/OsuModDifficultyAdjust.cs b/osu.Game.Rulesets.Osu/Mods/OsuModDifficultyAdjust.cs
index ff995e38ce..a638234dbd 100644
--- a/osu.Game.Rulesets.Osu/Mods/OsuModDifficultyAdjust.cs
+++ b/osu.Game.Rulesets.Osu/Mods/OsuModDifficultyAdjust.cs
@@ -59,8 +59,8 @@ namespace osu.Game.Rulesets.Osu.Mods
         {
             base.ApplySettings(difficulty);
 
-            difficulty.CircleSize = CircleSize.Value;
-            difficulty.ApproachRate = ApproachRate.Value;
+            ApplySetting(CircleSize, cs => difficulty.CircleSize = cs);
+            ApplySetting(ApproachRate, ar => difficulty.ApproachRate = ar);
         }
     }
 }
diff --git a/osu.Game/Rulesets/Mods/ModDifficultyAdjust.cs b/osu.Game/Rulesets/Mods/ModDifficultyAdjust.cs
index 72a4bb297f..a531e885db 100644
--- a/osu.Game/Rulesets/Mods/ModDifficultyAdjust.cs
+++ b/osu.Game/Rulesets/Mods/ModDifficultyAdjust.cs
@@ -116,18 +116,30 @@ namespace osu.Game.Rulesets.Mods
 
         internal override void CopyAdjustedSetting(IBindable target, object source)
         {
-            userChangedSettings[target] = true;
+            // if the value is non-bindable, it's presumably coming from an external source (like the API) - therefore presume it is not default.
+            // if the value is bindable, defer to the source's IsDefault to be able to tell.
+            userChangedSettings[target] = !(source is IBindable bindableSource) || !bindableSource.IsDefault;
             base.CopyAdjustedSetting(target, source);
         }
 
+        /// <summary>
+        /// Applies a setting from a configuration bindable using <paramref name="applyFunc"/>, if it has been changed by the user.
+        /// </summary>
+        protected void ApplySetting<T>(BindableNumber<T> setting, Action<T> applyFunc)
+            where T : struct, IComparable<T>, IConvertible, IEquatable<T>
+        {
+            if (userChangedSettings.TryGetValue(setting, out bool userChangedSetting) && userChangedSetting)
+                applyFunc.Invoke(setting.Value);
+        }
+
         /// <summary>
         /// Apply all custom settings to the provided beatmap.
         /// </summary>
         /// <param name="difficulty">The beatmap to have settings applied.</param>
         protected virtual void ApplySettings(BeatmapDifficulty difficulty)
         {
-            difficulty.DrainRate = DrainRate.Value;
-            difficulty.OverallDifficulty = OverallDifficulty.Value;
+            ApplySetting(DrainRate, dr => difficulty.DrainRate = dr);
+            ApplySetting(OverallDifficulty, od => difficulty.OverallDifficulty = od);
         }
     }
 }