Add basic track reloading support while inside the editor

osu.Game/Overlays/MusicController.cs

@@ -81,6 +81,11 @@ namespace osu.Game.Overlays
             mods.BindValueChanged(_ => ResetTrackAdjustments(), true);
         }
 
+        /// <summary>
+        /// Forcefully reload the current <see cref="WorkingBeatmap"/>'s track from disk.
+        /// </summary>
+        public void ForceReloadCurrentBeatmap() => changeTrack();
+
         /// <summary>
         /// Change the position of a <see cref="BeatmapSetInfo"/> in the current playlist.
         /// </summary>

osu.Game/Screens/Edit/Editor.cs

@@ -43,6 +43,7 @@ using osuTK.Input;
 namespace osu.Game.Screens.Edit
 {
     [Cached(typeof(IBeatSnapProvider))]
+    [Cached]
     public class Editor : ScreenWithBeatmapBackground, IKeyBindingHandler<GlobalAction>, IKeyBindingHandler<PlatformAction>, IBeatSnapProvider
     {
         public override float BackgroundParallaxAmount => 0.1f;
@@ -91,6 +92,9 @@ namespace osu.Game.Screens.Edit
         [Resolved]
         private IAPIProvider api { get; set; }
 
+        [Resolved]
+        private MusicController music { get; set; }
+
         [BackgroundDependencyLoader]
         private void load(OsuColour colours, GameHost host)
         {
@@ -98,9 +102,9 @@ namespace osu.Game.Screens.Edit
             beatDivisor.BindValueChanged(divisor => Beatmap.Value.BeatmapInfo.BeatDivisor = divisor.NewValue);
 
             // Todo: should probably be done at a DrawableRuleset level to share logic with Player.
-            var sourceClock = (IAdjustableClock)Beatmap.Value.Track ?? new StopwatchClock();
             clock = new EditorClock(Beatmap.Value, beatDivisor) { IsCoupled = false };
-            clock.ChangeSource(sourceClock);
+
+            UpdateClockSource();
 
             dependencies.CacheAs(clock);
             AddInternal(clock);
@@ -271,6 +275,15 @@ namespace osu.Game.Screens.Edit
             bottomBackground.Colour = colours.Gray2;
         }
 
+        /// <summary>
+        /// If the beatmap's track has changed, this method must be called to keep the editor in a valid state.
+        /// </summary>
+        public void UpdateClockSource()
+        {
+            var sourceClock = (IAdjustableClock)Beatmap.Value.Track ?? new StopwatchClock();
+            clock.ChangeSource(sourceClock);
+        }
+
         protected void Save()
         {
             // apply any set-level metadata changes.

osu.Game/Screens/Edit/EditorClock.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Linq;
+using osu.Framework.Audio.Track;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Transforms;
 using osu.Framework.Utils;
@@ -17,7 +18,7 @@ namespace osu.Game.Screens.Edit
     /// </summary>
     public class EditorClock : Component, IFrameBasedClock, IAdjustableClock, ISourceChangeableClock
     {
-        public readonly double TrackLength;
+        public double TrackLength;
 
         public ControlPointInfo ControlPointInfo;
 
@@ -190,7 +191,11 @@ namespace osu.Game.Screens.Edit
 
         public FrameTimeInfo TimeInfo => underlyingClock.TimeInfo;
 
-        public void ChangeSource(IClock source) => underlyingClock.ChangeSource(source);
+        public void ChangeSource(IClock source)
+        {
+            underlyingClock.ChangeSource(source);
+            TrackLength = (source as Track)?.Length ?? 60000;
+        }
 
         public IClock Source => underlyingClock.Source;
 

osu.Game/Screens/Edit/Setup/SetupScreen.cs

@@ -18,6 +18,7 @@ using osu.Game.Graphics.Sprites;
 using osu.Game.Graphics.UserInterface;
 using osu.Game.Graphics.UserInterfaceV2;
 using osu.Game.IO;
+using osu.Game.Overlays;
 using osuTK;
 using FileInfo = System.IO.FileInfo;
 
@@ -139,6 +140,12 @@ namespace osu.Game.Screens.Edit.Setup
         [Resolved]
         private FileStore files { get; set; }
 
+        [Resolved]
+        private MusicController music { get; set; }
+
+        [Resolved]
+        private Editor editor { get; set; }
+
         private void audioTrackChanged(ValueChangedEvent<string> filePath)
         {
             var info = new FileInfo(filePath.NewValue);
@@ -173,6 +180,10 @@ namespace osu.Game.Screens.Edit.Setup
             });
 
             Beatmap.Value.Metadata.AudioFile = info.Name;
+
+            music.ForceReloadCurrentBeatmap();
+
+            editor.UpdateClockSource();
         }
 
         private void onCommit(TextBox sender, bool newText)