Add tooltip text for offset adjustment slider

osu.Game/Localisation/BeatmapOffsetControlStrings.cs

@@ -29,6 +29,16 @@ namespace osu.Game.Localisation
         /// </summary>
         public static LocalisableString CalibrateUsingLastPlay => new TranslatableString(getKey(@"calibrate_using_last_play"), @"Calibrate using last play");
 
+        /// <summary>
+        /// "(hit objects appear later)"
+        /// </summary>
+        public static LocalisableString HitObjectsAppearLater => new TranslatableString(getKey(@"hit_objects_appear_later"), @"(hit objects appear later)");
+
+        /// <summary>
+        /// "(hit objects appear earlier)"
+        /// </summary>
+        public static LocalisableString HitObjectsAppearEarlier => new TranslatableString(getKey(@"hit_objects_appear_earlier"), @"(hit objects appear earlier)");
+
         private static string getKey(string key) => $@"{prefix}:{key}";
     }
 }

osu.Game/Screens/Play/PlayerSettings/BeatmapOffsetControl.cs

@@ -3,12 +3,14 @@
 
 using System;
 using System.ComponentModel;
+using System.Diagnostics;
 using System.Linq;
 using System.Threading.Tasks;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
+using osu.Framework.Localisation;
 using osu.Framework.Utils;
 using osu.Game.Beatmaps;
 using osu.Game.Database;
@@ -71,7 +73,7 @@ namespace osu.Game.Screens.Play.PlayerSettings
                 Spacing = new Vector2(10),
                 Children = new Drawable[]
                 {
-                    new PlayerSliderBar<double>
+                    new OffsetSliderBar
                     {
                         KeyboardStep = 5,
                         LabelText = BeatmapOffsetControlStrings.BeatmapOffset,
@@ -88,6 +90,30 @@ namespace osu.Game.Screens.Play.PlayerSettings
             };
         }
 
+        public class OffsetSliderBar : PlayerSliderBar<double>
+        {
+            protected override Drawable CreateControl() => new CustomSliderBar();
+
+            protected class CustomSliderBar : SliderBar
+            {
+                protected override LocalisableString GetTooltipText(double value)
+                {
+                    return value == 0
+                        ? new TranslatableString("_", @"{0} ms", base.GetTooltipText(value))
+                        : new TranslatableString("_", @"{0} ms {1}", base.GetTooltipText(value), getEarlyLateText(value));
+                }
+
+                private LocalisableString getEarlyLateText(double value)
+                {
+                    Debug.Assert(value != 0);
+
+                    return value > 0
+                        ? BeatmapOffsetControlStrings.HitObjectsAppearLater
+                        : BeatmapOffsetControlStrings.HitObjectsAppearEarlier;
+                }
+            }
+        }
+
         protected override void LoadComplete()
         {
             base.LoadComplete();

osu.Game/Screens/Play/PlayerSettings/PlayerSliderBar.cs

@@ -15,13 +15,15 @@ namespace osu.Game.Screens.Play.PlayerSettings
     {
         public OsuSliderBar<T> Bar => (OsuSliderBar<T>)Control;
 
-        protected override Drawable CreateControl() => new SliderBar
+        protected override Drawable CreateControl() => new SliderBar();
-        {
-            RelativeSizeAxes = Axes.X
-        };
 
-        private class SliderBar : OsuSliderBar<T>
+        protected class SliderBar : OsuSliderBar<T>
         {
+            public SliderBar()
+            {
+                RelativeSizeAxes = Axes.X;
+            }
+
             [BackgroundDependencyLoader]
             private void load(OsuColour colours)
             {