Give TestWorkingBeatmap a reference clock

osu.Game.Rulesets.Taiko.Tests/TestCaseTaikoPlayfield.cs

@@ -78,7 +78,7 @@ namespace osu.Game.Rulesets.Taiko.Tests
                     Ruleset = new TaikoRuleset().RulesetInfo
                 },
                 ControlPointInfo = controlPointInfo
-            });
+            }, Clock);
 
             Add(playfieldContainer = new Container
             {

osu.Game.Tests/Visual/TestCaseEditorCompose.cs

@@ -19,7 +19,7 @@ namespace osu.Game.Tests.Visual
         [BackgroundDependencyLoader]
         private void load()
         {
-            Beatmap.Value = new TestWorkingBeatmap(new OsuRuleset().RulesetInfo);
+            Beatmap.Value = new TestWorkingBeatmap(new OsuRuleset().RulesetInfo, Clock);
             Child = new ComposeScreen();
         }
     }

osu.Game.Tests/Visual/TestCaseEditorSeekSnapping.cs

@@ -48,7 +48,7 @@ namespace osu.Game.Tests.Visual
                 }
             };
 
-            Beatmap.Value = new TestWorkingBeatmap(testBeatmap);
+            Beatmap.Value = new TestWorkingBeatmap(testBeatmap, Clock);
 
             Child = new TimingPointVisualiser(testBeatmap, 5000) { Clock = Clock };
         }

osu.Game.Tests/Visual/TestCaseEditorSummaryTimeline.cs

@@ -21,7 +21,7 @@ namespace osu.Game.Tests.Visual
         [BackgroundDependencyLoader]
         private void load()
         {
-            Beatmap.Value = new TestWorkingBeatmap(new OsuRuleset().RulesetInfo);
+            Beatmap.Value = new TestWorkingBeatmap(new OsuRuleset().RulesetInfo, Clock);
 
             Add(new SummaryTimeline
             {

osu.Game.Tests/Visual/TestCasePlaybackControl.cs

@@ -29,7 +29,7 @@ namespace osu.Game.Tests.Visual
                 Size = new Vector2(200,100)
             };
 
-            Beatmap.Value = new TestWorkingBeatmap(new Beatmap());
+            Beatmap.Value = new TestWorkingBeatmap(new Beatmap(), Clock);
 
             Child = playback;
         }

osu.Game/Tests/Beatmaps/TestWorkingBeatmap.cs

@@ -1,29 +1,106 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System;
 using osu.Framework.Audio.Track;
 using osu.Framework.Graphics.Textures;
+using osu.Framework.Timing;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets;
+using osuTK;
 
 namespace osu.Game.Tests.Beatmaps
 {
     public class TestWorkingBeatmap : WorkingBeatmap
     {
-        public TestWorkingBeatmap(RulesetInfo ruleset)
+        private readonly TrackVirtualManual track;
-            : this(new TestBeatmap(ruleset))
+        private readonly IBeatmap beatmap;
+
+        /// <summary>
+        /// Create an instance which creates a <see cref="TestBeatmap"/> for the provided ruleset when requested.
+        /// </summary>
+        /// <param name="ruleset">The target ruleset.</param>
+        /// <param name="referenceClock">An optional clock which should be used instead of a stopwatch for virtual time progression.</param>
+        public TestWorkingBeatmap(RulesetInfo ruleset, IFrameBasedClock referenceClock)
+            : this(new TestBeatmap(ruleset), referenceClock)
         {
         }
 
-        public TestWorkingBeatmap(IBeatmap beatmap)
+        /// <summary>
+        /// Create an instance which provides the <see cref="IBeatmap"/> when requested.
+        /// </summary>
+        /// <param name="beatmap">The beatmap</param>
+        /// <param name="referenceClock">An optional clock which should be used instead of a stopwatch for virtual time progression.</param>
+        public TestWorkingBeatmap(IBeatmap beatmap, IFrameBasedClock referenceClock = null)
             : base(beatmap.BeatmapInfo)
         {
             this.beatmap = beatmap;
+
+            if (referenceClock != null)
+                track = new TrackVirtualManual(referenceClock);
         }
 
-        private readonly IBeatmap beatmap;
         protected override IBeatmap GetBeatmap() => beatmap;
         protected override Texture GetBackground() => null;
-        protected override Track GetTrack() => null;
+        protected override Track GetTrack() => track;
+    }
+
+    /// <summary>
+    /// A virtual track which tracks a reference clock.
+    /// </summary>
+    public class TrackVirtualManual : Track
+    {
+        private readonly IFrameBasedClock referenceClock;
+        private readonly ManualClock clock;
+
+        private bool running;
+        private double offset;
+
+        public TrackVirtualManual(IFrameBasedClock referenceClock)
+        {
+            this.referenceClock = referenceClock;
+            Length = double.PositiveInfinity;
+            clock = new ManualClock();
+        }
+
+        public override bool Seek(double seek)
+        {
+            offset = MathHelper.Clamp(seek, 0, Length) - referenceClock.CurrentTime;
+            return true;
+        }
+
+        public override void Start()
+        {
+            running = true;
+            Seek(0);
+        }
+
+        public override void Reset()
+        {
+            Seek(0);
+            base.Reset();
+        }
+
+        public override void Stop()
+        {
+            running = false;
+        }
+
+        public override bool IsRunning => running;
+
+        public override double CurrentTime => running ? clock.CurrentTime : 0;
+
+        protected override void UpdateState()
+        {
+            base.UpdateState();
+
+            clock.CurrentTime = Math.Min(referenceClock.CurrentTime + offset, Length);
+
+            if (CurrentTime >= Length)
+            {
+                Stop();
+                RaiseCompleted();
+            }
+        }
     }
 }

osu.Game/Tests/Visual/EditorTestCase.cs

@@ -24,7 +24,7 @@ namespace osu.Game.Tests.Visual
         [BackgroundDependencyLoader]
         private void load()
         {
-            Beatmap.Value = new TestWorkingBeatmap(ruleset.RulesetInfo);
+            Beatmap.Value = new TestWorkingBeatmap(ruleset.RulesetInfo, Clock);
 
             LoadComponentAsync(new Editor(), LoadScreen);
         }

osu.Game/Tests/Visual/TestCasePlayer.cs

@@ -99,7 +99,7 @@ namespace osu.Game.Tests.Visual
         private Player loadPlayerFor(Ruleset r)
         {
             var beatmap = CreateBeatmap(r);
-            var working = new TestWorkingBeatmap(beatmap);
+            var working = new TestWorkingBeatmap(beatmap, Clock);
 
             workingWeakReferences.Add(working);