Add initial game-wide beatmap flow.

osu.Game/Beatmaps/Drawable/BeatmapGroup.cs

@@ -2,6 +2,7 @@
 //Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using osu.Framework;
 using osu.Framework.Graphics;
@@ -27,6 +28,8 @@ namespace osu.Game.Beatmaps.Drawable
 
         private BeatmapGroupState state;
 
+        public IEnumerable<BeatmapPanel> BeatmapPanels;
+
         public BeatmapGroupState State
         {
             get { return state; }
@@ -62,6 +65,16 @@ namespace osu.Game.Beatmaps.Drawable
             AutoSizeAxes = Axes.Y;
             RelativeSizeAxes = Axes.X;
 
+            BeatmapPanels = beatmapSet.Beatmaps.Select(b =>
+                new BeatmapPanel(this.beatmapSet, b)
+                {
+                    GainedSelection = panelGainedSelection,
+                    Anchor = Anchor.TopRight,
+                    Origin = Anchor.TopRight,
+                    RelativeSizeAxes = Axes.X,
+                });
+                
+
             Children = new[]
             {
                 new FlowContainer
@@ -87,15 +100,7 @@ namespace osu.Game.Beatmaps.Drawable
                             Spacing = new Vector2(0, 5),
                             Direction = FlowDirection.VerticalOnly,
                             Alpha = 0,
-                            Children = this.beatmapSet.Beatmaps.Select(b =>
+                            Children = BeatmapPanels
-                                new BeatmapPanel(this.beatmapSet, b)
-                                {
-                                    GainedSelection = panelGainedSelection,
-                                    Anchor = Anchor.TopRight,
-                                    Origin = Anchor.TopRight,
-                                    RelativeSizeAxes = Axes.X,
-                                }
-                            )
                         }
                     }
                 }

osu.Game/Beatmaps/WorkingBeatmap.cs

@@ -17,8 +17,8 @@ namespace osu.Game.Beatmaps
         {
             get
             {
-                if (track == null)
+                if (track != null) return track;
-                {
+
                 try
                 {
                     var trackData = Reader.ReadFile(Beatmap.Metadata.AudioFile);
@@ -26,7 +26,6 @@ namespace osu.Game.Beatmaps
                         track = new AudioTrackBass(trackData);
                 }
                 catch { }
-                }
 
                 return track;
             }

osu.Game/Database/BeatmapDatabase.cs

@@ -136,7 +136,7 @@ namespace osu.Game.Database
             return Query<BeatmapSetInfo>().Where(s => s.BeatmapSetID == id).FirstOrDefault();
         }
 
-        public WorkingBeatmap GetBeatmapData(BeatmapInfo beatmapInfo)
+        public WorkingBeatmap GetWorkingBeatmap(BeatmapInfo beatmapInfo)
         {
             var beatmapSet = Query<BeatmapSetInfo>().Where(s => s.BeatmapSetID == beatmapInfo.BeatmapSetID).FirstOrDefault();
             if (beatmapSet == null)
@@ -150,7 +150,7 @@ namespace osu.Game.Database
 
         public Beatmap GetBeatmap(BeatmapInfo beatmapInfo)
         {
-            using (WorkingBeatmap data = GetBeatmapData(beatmapInfo))
+            using (WorkingBeatmap data = GetWorkingBeatmap(beatmapInfo))
                 return data.Beatmap;
         }
 

osu.Game/Database/BeatmapInfo.cs

@@ -7,7 +7,7 @@ using SQLiteNetExtensions.Attributes;
 
 namespace osu.Game.Database
 {
-    public class BeatmapInfo
+    public class BeatmapInfo : IEquatable<BeatmapInfo>
     {
         [PrimaryKey]
         public int BeatmapID { get; set; }
@@ -64,5 +64,10 @@ namespace osu.Game.Database
         
         // Metadata
         public string Version { get; set; }
+
+        public bool Equals(BeatmapInfo other)
+        {
+            return BeatmapID == other?.BeatmapID;
+        }
     }
 }

osu.Game/GameModes/Menu/Intro.cs

@@ -10,6 +10,8 @@ using osu.Framework.Graphics.Transformations;
 using osu.Game.GameModes.Backgrounds;
 using OpenTK.Graphics;
 using osu.Framework;
+using osu.Framework.Configuration;
+using osu.Game.Beatmaps;
 
 namespace osu.Game.GameModes.Menu
 {

osu.Game/GameModes/OsuGameMode.cs

@@ -3,17 +3,20 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using osu.Framework.Configuration;
 using osu.Framework.GameModes;
 using osu.Framework.Graphics.Containers;
+using osu.Game.Beatmaps;
 using osu.Game.Graphics.Background;
 using osu.Game.Graphics.Containers;
 
 namespace osu.Game.GameModes
 {
-    public class OsuGameMode : GameMode
+    public abstract class OsuGameMode : GameMode
     {
         internal BackgroundMode Background { get; private set; }
 
@@ -23,6 +26,64 @@ namespace osu.Game.GameModes
         /// </summary>
         protected virtual BackgroundMode CreateBackground() => null;
 
+        private bool boundToBeatmap;
+        private Bindable<WorkingBeatmap> beatmap;
+
+        public WorkingBeatmap Beatmap
+        {
+            get
+            {
+                bindBeatmap();
+                return beatmap.Value;
+            }
+            set
+            {
+                bindBeatmap();
+                beatmap.Value = value;
+            }
+        }
+
+        private void bindBeatmap()
+        {
+            if (beatmap == null)
+                beatmap = new Bindable<WorkingBeatmap>();
+
+            if (!boundToBeatmap)
+            {
+                beatmap.ValueChanged += beatmap_ValueChanged;
+                boundToBeatmap = true;
+            }
+        }
+
+        protected override void Dispose(bool isDisposing)
+        {
+            if (boundToBeatmap)
+                beatmap.ValueChanged -= beatmap_ValueChanged;
+
+            base.Dispose(isDisposing);
+        }
+
+        private void beatmap_ValueChanged(object sender, EventArgs e)
+        {
+            OnBeatmapChanged(beatmap.Value);
+        }
+
+        public override bool Push(GameMode mode)
+        {
+            OsuGameMode nextOsu = mode as OsuGameMode;
+            if (nextOsu != null)
+            {
+                nextOsu.beatmap = beatmap;
+            }
+
+            return base.Push(mode);
+        }
+
+        protected virtual void OnBeatmapChanged(WorkingBeatmap beatmap)
+        {
+
+        }
+
         protected override void OnEntering(GameMode last)
         {
             OsuGameMode lastOsu = last as OsuGameMode;

osu.Game/GameModes/Play/PlaySongSelect.cs

@@ -16,8 +16,11 @@ using OpenTK;
 using OpenTK.Graphics;
 using osu.Framework.Graphics.UserInterface;
 using System.Threading.Tasks;
+using osu.Framework.Audio.Track;
 using osu.Game.Beatmaps.Drawable;
 using osu.Framework.Extensions.IEnumerableExtensions;
+using osu.Game.Beatmaps;
+using osu.Framework.GameModes;
 
 namespace osu.Game.GameModes.Play
 {
@@ -26,10 +29,12 @@ namespace osu.Game.GameModes.Play
         private Bindable<PlayMode> playMode;
         private BeatmapDatabase database;
         private BeatmapGroup selectedBeatmapGroup;
+        private BeatmapInfo selectedBeatmapInfo;
         // TODO: use currently selected track as bg
         protected override BackgroundMode CreateBackground() => new BackgroundModeCustom(@"Backgrounds/bg4");
         private ScrollContainer scrollContainer;
-        private FlowContainer setList;
+        private FlowContainer beatmapSetFlow;
+        private TrackManager trackManager;
 
         /// <param name="database">Optionally provide a database to use instead of the OsuGame one.</param>
         public PlaySongSelect(BeatmapDatabase database = null)
@@ -73,7 +78,7 @@ namespace osu.Game.GameModes.Play
                     Origin = Anchor.CentreRight,
                     Children = new Drawable[]
                     {
-                        setList = new FlowContainer
+                        beatmapSetFlow = new FlowContainer
                         {
                             Padding = new MarginPadding { Left = 25, Top = 25, Bottom = 25 + bottomToolHeight },
                             RelativeSizeAxes = Axes.X,
@@ -123,7 +128,7 @@ namespace osu.Game.GameModes.Play
             if (osuGame != null)
             {
                 playMode = osuGame.PlayMode;
-                playMode.ValueChanged += PlayMode_ValueChanged;
+                playMode.ValueChanged += playMode_ValueChanged;
                 // Temporary:
                 scrollContainer.Padding = new MarginPadding { Top = osuGame.Toolbar.Height };
             }
@@ -133,22 +138,68 @@ namespace osu.Game.GameModes.Play
 
             database.BeatmapSetAdded += s => Schedule(() => addBeatmapSet(s));
 
+            trackManager = game.Audio.Track;
+
             Task.Factory.StartNew(addBeatmapSets);
         }
 
+        protected override void OnEntering(GameMode last)
+        {
+            base.OnEntering(last);
+            ensurePlayingSelected();
+        }
+
+        protected override void OnResuming(GameMode last)
+        {
+            ensurePlayingSelected();
+
+            base.OnResuming(last);
+        }
+
         protected override void Dispose(bool isDisposing)
         {
             base.Dispose(isDisposing);
             if (playMode != null)
-                playMode.ValueChanged -= PlayMode_ValueChanged;
+                playMode.ValueChanged -= playMode_ValueChanged;
         }
 
-        private void PlayMode_ValueChanged(object sender, EventArgs e)
+        private void playMode_ValueChanged(object sender, EventArgs e)
         {
         }
 
-        private void selectBeatmap(BeatmapGroup group, BeatmapInfo beatmap)
+        protected override void OnBeatmapChanged(WorkingBeatmap beatmap)
         {
+            base.OnBeatmapChanged(beatmap);
+            selectBeatmap(beatmap.Beatmap.BeatmapInfo);
+        }
+
+        private void selectBeatmap(BeatmapInfo beatmap)
+        {
+            if (beatmap.Equals(selectedBeatmapInfo))
+                return;
+
+            beatmapSetFlow.Children.Cast<BeatmapGroup>().First(b =>
+            {
+                var panel = b.BeatmapPanels.FirstOrDefault(p => p.Beatmap.Equals(beatmap));
+                panel?.TriggerClick();
+                return panel != null;
+            });
+        }
+
+        /// <summary>
+        /// selection has been changed as the result of interaction with the carousel.
+        /// </summary>
+        private void selectionChanged(BeatmapGroup group, BeatmapInfo beatmap)
+        {
+            selectedBeatmapInfo = beatmap;
+
+            if (!beatmap.Equals(Beatmap?.Beatmap?.BeatmapInfo))
+            {
+                Beatmap = database.GetWorkingBeatmap(beatmap);
+            }
+
+            ensurePlayingSelected();
+
             if (selectedBeatmapGroup == group)
                 return;
 
@@ -158,6 +209,17 @@ namespace osu.Game.GameModes.Play
             selectedBeatmapGroup = group;
         }
 
+        private void ensurePlayingSelected()
+        {
+            var track = Beatmap?.Track;
+
+            if (track != null)
+            {
+                trackManager.SetExclusive(track);
+                track.Start();
+            }
+        }
+
         private void addBeatmapSet(BeatmapSetInfo beatmapSet)
         {
             beatmapSet = database.GetWithChildren<BeatmapSetInfo>(beatmapSet.BeatmapSetID);
@@ -165,9 +227,9 @@ namespace osu.Game.GameModes.Play
             beatmapSet.Beatmaps = beatmapSet.Beatmaps.OrderBy(b => b.BaseDifficulty.OverallDifficulty).ToList();
             Schedule(() =>
             {
-                var group = new BeatmapGroup(beatmapSet) { SelectionChanged = selectBeatmap };
+                var group = new BeatmapGroup(beatmapSet) { SelectionChanged = selectionChanged };
-                setList.Add(group);
+                beatmapSetFlow.Add(group);
-                if (setList.Children.Count() == 1)
+                if (beatmapSetFlow.Children.Count() == 1)
                     group.State = BeatmapGroupState.Expanded;
             });
         }

osu.Game/GameModes/Play/Player.cs

@@ -22,7 +22,6 @@ namespace osu.Game.GameModes.Play
         protected override BackgroundMode CreateBackground() => new BackgroundModeCustom(@"Backgrounds/bg4");
 
         public BeatmapInfo BeatmapInfo;
-        public WorkingBeatmap Beatmap;
 
         public PlayMode PreferredPlayMode;
 
@@ -31,16 +30,13 @@ namespace osu.Game.GameModes.Play
         private InterpolatingFramedClock playerClock;
         private IAdjustableClock sourceClock;
 
-        protected override void Dispose(bool isDisposing)
-        {
-            Beatmap?.Dispose();
-            base.Dispose(isDisposing);
-        }
-
         protected override bool OnExiting(GameMode next)
+        {
+            if (next == null)
             {
                 //eagerly dispose as the finalizer runs too late right now.
                 Beatmap?.Dispose();
+            }
 
             return base.OnExiting(next);
         }
@@ -52,7 +48,7 @@ namespace osu.Game.GameModes.Play
             try
             {
                 if (Beatmap == null)
-                    Beatmap = ((OsuGame)game).Beatmaps.GetBeatmapData(BeatmapInfo);
+                    Beatmap = ((OsuGame)game).Beatmaps.GetWorkingBeatmap(BeatmapInfo);
             }
             catch
             {
@@ -69,27 +65,28 @@ namespace osu.Game.GameModes.Play
                 sourceClock = track;
             }
 
-            sourceClock = (IAdjustableClock)Beatmap.Track ?? new StopwatchClock();
+            sourceClock = (IAdjustableClock)track ?? new StopwatchClock();
             playerClock = new InterpolatingFramedClock(sourceClock);
 
             Schedule(() =>
             {
+                sourceClock.Reset();
                 sourceClock.Start();
             });
 
             HitRenderer hitRenderer;
             ScoreOverlay scoreOverlay;
 
-            if (Beatmap.Beatmap.BeatmapInfo?.Mode > PlayMode.Osu)
+            var beatmap = Beatmap.Beatmap;
+
+            if (beatmap.BeatmapInfo?.Mode > PlayMode.Osu)
             {
                 //we only support osu! mode for now because the hitobject parsing is crappy and needs a refactor.
                 Exit();
                 return;
             }
 
-            PlayMode usablePlayMode = Beatmap.Beatmap.BeatmapInfo?.Mode > PlayMode.Osu ? Beatmap.Beatmap.BeatmapInfo.Mode : PreferredPlayMode;
+            PlayMode usablePlayMode = beatmap.BeatmapInfo?.Mode > PlayMode.Osu ? beatmap.BeatmapInfo.Mode : PreferredPlayMode;
-
-
 
             switch (usablePlayMode)
             {
@@ -98,7 +95,7 @@ namespace osu.Game.GameModes.Play
 
                     hitRenderer = new OsuHitRenderer
                     {
-                        Objects = Beatmap.Beatmap.HitObjects,
+                        Objects = beatmap.HitObjects,
                         Anchor = Anchor.Centre,
                         Origin = Anchor.Centre
                     };
@@ -108,7 +105,7 @@ namespace osu.Game.GameModes.Play
 
                     hitRenderer = new TaikoHitRenderer
                     {
-                        Objects = Beatmap.Beatmap.HitObjects,
+                        Objects = beatmap.HitObjects,
                         Anchor = Anchor.Centre,
                         Origin = Anchor.Centre
                     };
@@ -118,7 +115,7 @@ namespace osu.Game.GameModes.Play
 
                     hitRenderer = new CatchHitRenderer
                     {
-                        Objects = Beatmap.Beatmap.HitObjects,
+                        Objects = beatmap.HitObjects,
                         Anchor = Anchor.Centre,
                         Origin = Anchor.Centre
                     };
@@ -128,7 +125,7 @@ namespace osu.Game.GameModes.Play
 
                     hitRenderer = new ManiaHitRenderer
                     {
-                        Objects = Beatmap.Beatmap.HitObjects,
+                        Objects = beatmap.HitObjects,
                         Anchor = Anchor.Centre,
                         Origin = Anchor.Centre
                     };

osu.Game/OsuGame.cs

@@ -70,7 +70,10 @@ namespace osu.Game
                     RelativeSizeAxes = Axes.Both,
                     ActivateRequested = delegate { volume.Show(); }
                 },
-                intro = new Intro(),
+                intro = new Intro
+                {
+                    Beatmap = Beatmap
+                },
                 Toolbar = new Toolbar
                 {
                     OnHome = delegate { MainMenu?.MakeCurrent(); },

osu.Game/OsuGameBase.cs

@@ -1,10 +1,13 @@
-using osu.Framework;
+using System;
+using osu.Framework;
+using osu.Framework.Configuration;
 using osu.Framework.GameModes;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Cursor;
 using osu.Framework.Graphics.Textures;
 using osu.Framework.IO.Stores;
+using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.IO;
 using osu.Game.Configuration;
 using osu.Game.Database;
@@ -32,6 +35,8 @@ namespace osu.Game
 
         public CursorContainer Cursor;
 
+        public readonly Bindable<WorkingBeatmap> Beatmap = new Bindable<WorkingBeatmap>();
+
         public OsuGameBase()
         {
             AddInternal(ratioContainer = new RatioAdjust());
@@ -41,6 +46,13 @@ namespace osu.Game
                 Options = new Options(),
                 Cursor = new OsuCursorContainer()
             };
+
+            Beatmap.ValueChanged += Beatmap_ValueChanged;
+        }
+
+        private void Beatmap_ValueChanged(object sender, EventArgs e)
+        {
+            throw new NotImplementedException();
         }
 
         public override void Load(BaseGame game)