Merge pull request #11818 from peppy/fix-default-preview-time

Fix preview point not being set correctly for beatmaps which don't specify an explicit time value

osu.Game/Beatmaps/BeatmapMetadata.cs

@@ -51,7 +51,12 @@ namespace osu.Game.Beatmaps
         [JsonProperty(@"tags")]
         public string Tags { get; set; }
 
+        /// <summary>
+        /// The time in milliseconds to begin playing the track for preview purposes.
+        /// If -1, the track should begin playing at 40% of its length.
+        /// </summary>
         public int PreviewTime { get; set; }
+
         public string AudioFile { get; set; }
         public string BackgroundFile { get; set; }
 

osu.Game/Beatmaps/WorkingBeatmap.cs

@@ -266,6 +266,26 @@ namespace osu.Game.Beatmaps
         [NotNull]
         public Track LoadTrack() => loadedTrack = GetBeatmapTrack() ?? GetVirtualTrack(1000);
 
+        /// <summary>
+        /// Reads the correct track restart point from beatmap metadata and sets looping to enabled.
+        /// </summary>
+        public void PrepareTrackForPreviewLooping()
+        {
+            Track.Looping = true;
+            Track.RestartPoint = Metadata.PreviewTime;
+
+            if (Track.RestartPoint == -1)
+            {
+                if (!Track.IsLoaded)
+                {
+                    // force length to be populated (https://github.com/ppy/osu-framework/issues/4202)
+                    Track.Seek(Track.CurrentTime);
+                }
+
+                Track.RestartPoint = 0.4f * Track.Length;
+            }
+        }
+
         /// <summary>
         /// Transfer a valid audio track into this working beatmap. Used as an optimisation to avoid reload / track swap
         /// across difficulties in the same beatmap set.

osu.Game/Screens/Menu/IntroScreen.cs

@@ -168,7 +168,7 @@ namespace osu.Game.Screens.Menu
         {
             // Only start the current track if it is the menu music. A beatmap's track is started when entering the Main Menu.
             if (UsingThemedIntro)
-                Track.Restart();
+                Track.Start();
         }
 
         protected override void LogoArriving(OsuLogo logo, bool resuming)

osu.Game/Screens/Menu/MainMenu.cs

@@ -179,14 +179,15 @@ namespace osu.Game.Screens.Menu
             base.OnEntering(last);
             buttons.FadeInFromZero(500);
 
-            var metadata = Beatmap.Value.Metadata;
-
             if (last is IntroScreen && musicController.TrackLoaded)
             {
-                if (!musicController.CurrentTrack.IsRunning)
+                var track = musicController.CurrentTrack;
+
+                // presume the track is the current beatmap's track. not sure how correct this assumption is but it has worked until now.
+                if (!track.IsRunning)
                 {
-                    musicController.CurrentTrack.Seek(metadata.PreviewTime != -1 ? metadata.PreviewTime : 0.4f * musicController.CurrentTrack.Length);
-                    musicController.CurrentTrack.Start();
+                    Beatmap.Value.PrepareTrackForPreviewLooping();
+                    track.Restart();
                 }
             }
 

osu.Game/Screens/OnlinePlay/Match/RoomSubScreen.cs

@@ -173,9 +173,7 @@ namespace osu.Game.Screens.OnlinePlay.Match
 
             if (track != null)
             {
-                track.RestartPoint = Beatmap.Value.Metadata.PreviewTime;
-                track.Looping = true;
-
+                Beatmap.Value.PrepareTrackForPreviewLooping();
                 music?.EnsurePlayingSomething();
             }
         }
@@ -185,10 +183,7 @@ namespace osu.Game.Screens.OnlinePlay.Match
             var track = Beatmap?.Value?.Track;
 
             if (track != null)
-            {
                 track.Looping = false;
-                track.RestartPoint = 0;
-            }
         }
     }
 }

osu.Game/Screens/Select/SongSelect.cs

@@ -648,8 +648,9 @@ namespace osu.Game.Screens.Select
         {
             Debug.Assert(!isHandlingLooping);
 
-            music.CurrentTrack.Looping = isHandlingLooping = true;
+            isHandlingLooping = true;
 
+            ensureTrackLooping(Beatmap.Value, TrackChangeDirection.None);
             music.TrackChanged += ensureTrackLooping;
         }
 
@@ -665,7 +666,7 @@ namespace osu.Game.Screens.Select
         }
 
         private void ensureTrackLooping(WorkingBeatmap beatmap, TrackChangeDirection changeDirection)
-            => music.CurrentTrack.Looping = true;
+            => beatmap.PrepareTrackForPreviewLooping();
 
         public override bool OnBackButton()
         {
@@ -719,8 +720,6 @@ namespace osu.Game.Screens.Select
 
             bool isNewTrack = !lastTrack.TryGetTarget(out var last) || last != track;
 
-            track.RestartPoint = Beatmap.Value.Metadata.PreviewTime;
-
             if (!track.IsRunning && (music.UserPauseRequested != true || isNewTrack))
                 music.Play(true);