Refactors the music player.

OpenRA.Game/Game.cs

@@ -286,7 +286,6 @@ namespace OpenRA
 			Console.WriteLine("Loading mod: {0}", mod);
 			Settings.Game.Mod = mod;
 
-			Sound.StopMusic();
 			Sound.StopVideo();
 			Sound.Initialize();
 

OpenRA.Game/OpenRA.Game.csproj

@@ -182,6 +182,7 @@
     <Compile Include="Traits\Util.cs" />
     <Compile Include="Traits\ValidateOrder.cs" />
     <Compile Include="Traits\World\Country.cs" />
+    <Compile Include="Traits\World\MusicPlaylist.cs" />
     <Compile Include="Traits\World\ResourceType.cs" />
     <Compile Include="Traits\World\ScreenShaker.cs" />
     <Compile Include="Traits\World\Shroud.cs" />

OpenRA.Game/Traits/World/MusicPlaylist.cs

@@ -0,0 +1,150 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2015 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation. For more information,
+ * see COPYING.
+ */
+#endregion
+
+using System;
+using System.Linq;
+using OpenRA.GameRules;
+
+namespace OpenRA.Traits
+{
+	[Desc("Trait for music handling. Attach this to the world actor.")]
+	public class MusicPlaylistInfo : ITraitInfo
+	{
+		public readonly string StartingMusic = null;
+		public readonly bool LoopStartingMusic = false;
+
+		public object Create(ActorInitializer init) { return new MusicPlaylist(init.World, this); }
+	}
+
+	public class MusicPlaylist : INotifyActorDisposing
+	{
+		readonly MusicInfo[] random;
+		readonly MusicInfo[] playlist;
+
+		public readonly bool IsMusicAvailable;
+
+		MusicInfo currentSong;
+		bool repeat;
+
+		public MusicPlaylist(World world, MusicPlaylistInfo info)
+		{
+			IsMusicAvailable = world.Map.Rules.InstalledMusic.Any();
+
+			playlist = world.Map.Rules.InstalledMusic.Select(a => a.Value).ToArray();
+
+			if (!IsMusicAvailable)
+				return;
+
+			random = playlist.Shuffle(Game.CosmeticRandom).ToArray();
+
+			if (Game.Settings.Sound.MapMusic
+				&& !string.IsNullOrEmpty(info.StartingMusic)
+				&& world.Map.Rules.Music.ContainsKey(info.StartingMusic)
+				&& world.Map.Rules.Music[info.StartingMusic].Exists)
+			{
+				currentSong = world.Map.Rules.Music[info.StartingMusic];
+				repeat = info.LoopStartingMusic;
+			}
+			else
+			{
+				currentSong = Game.Settings.Sound.Shuffle ? random.First() : playlist.First();
+				repeat = Game.Settings.Sound.Repeat;
+			}
+
+			Play();
+		}
+
+		public MusicInfo CurrentSong()
+		{
+			return currentSong;
+		}
+
+		public MusicInfo[] AvailablePlaylist()
+		{
+			// TO-DO: add filter options for Race-specific music
+			return playlist;
+		}
+
+		void Play()
+		{
+			if (currentSong == null || !IsMusicAvailable)
+				return;
+
+			Sound.PlayMusicThen(currentSong, () =>
+			{
+				if (!repeat)
+					currentSong = GetNextSong();
+
+				Play();
+			});
+		}
+
+		public void Play(MusicInfo music)
+		{
+			if (music == null || !IsMusicAvailable)
+				return;
+
+			currentSong = music;
+			repeat = Game.Settings.Sound.Repeat;
+
+			Sound.PlayMusicThen(music, () =>
+			{
+				if (!repeat)
+					currentSong = GetNextSong();
+
+				Play();
+			});
+		}
+
+		public void Play(MusicInfo music, Action onComplete)
+		{
+			if (music == null || !IsMusicAvailable)
+				return;
+
+			currentSong = music;
+			Sound.PlayMusicThen(music, onComplete);
+		}
+
+		public MusicInfo GetNextSong()
+		{
+			return GetSong(false);
+		}
+
+		public MusicInfo GetPrevSong()
+		{
+			return GetSong(true);
+		}
+
+		MusicInfo GetSong(bool reverse)
+		{
+			if (!IsMusicAvailable)
+				return null;
+
+			var songs = Game.Settings.Sound.Shuffle ? random : playlist;
+
+			return reverse ? songs.SkipWhile(m => m != currentSong)
+				.Skip(1).FirstOrDefault() ?? songs.FirstOrDefault() :
+				songs.Reverse().SkipWhile(m => m != currentSong)
+				.Skip(1).FirstOrDefault() ?? songs.Reverse().FirstOrDefault();
+		}
+
+		public void Stop()
+		{
+			currentSong = null;
+			Sound.StopMusic();
+		}
+
+		public void Disposing(Actor self)
+		{
+			if (currentSong != null)
+				Stop();
+		}
+	}
+}

OpenRA.Game/World.cs

@@ -388,7 +388,6 @@ namespace OpenRA
 			frameEndActions.Clear();
 
 			Sound.StopAudio();
-			Sound.StopMusic();
 			Sound.StopVideo();
 
 			// Dispose newer actors first, and the world actor last

OpenRA.Mods.Common/Scripting/Global/MediaGlobal.cs

@@ -11,26 +11,28 @@
 using System;
 using System.Drawing;
 using System.IO;
-using System.Linq;
 using Eluant;
 using OpenRA.Effects;
 using OpenRA.FileFormats;
 using OpenRA.FileSystem;
-using OpenRA.GameRules;
 using OpenRA.Graphics;
 using OpenRA.Mods.Common.Effects;
 using OpenRA.Scripting;
+using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Scripting
 {
 	[ScriptGlobal("Media")]
 	public class MediaGlobal : ScriptGlobal
 	{
-		World world;
+		readonly World world;
+		readonly MusicPlaylist playlist;
+
 		public MediaGlobal(ScriptContext context)
 			: base(context)
 		{
 			world = context.World;
+			playlist = world.WorldActor.Trait<MusicPlaylist>();
 		}
 
 		[Desc("Play an announcer voice listed in notifications.yaml")]
@@ -51,23 +53,15 @@ namespace OpenRA.Mods.Common.Scripting
 			Sound.Play(file);
 		}
 
-		MusicInfo previousMusic;
 		Action onComplete;
 		[Desc("Play track defined in music.yaml or keep it empty for a random song.")]
 		public void PlayMusic(string track = null, LuaFunction func = null)
 		{
-			if (!Game.Settings.Sound.MapMusic)
-				return;
-
-			var music = world.Map.Rules.InstalledMusic.Select(a => a.Value).ToArray();
-			if (!music.Any())
+			if (!Game.Settings.Sound.MapMusic || !playlist.IsMusicAvailable)
 				return;
 
 			var musicInfo = !string.IsNullOrEmpty(track) ? world.Map.Rules.Music[track]
-			: Game.Settings.Sound.Repeat && previousMusic != null ? previousMusic
-			: Game.Settings.Sound.Shuffle ? music.Random(Game.CosmeticRandom)
-			: previousMusic == null ? music.First()
-			: music.SkipWhile(s => s != previousMusic).Skip(1).First();
+			: playlist.GetNextSong();
 
 			if (func != null)
 			{
@@ -84,19 +78,17 @@ namespace OpenRA.Mods.Common.Scripting
 						Context.FatalError(e.Message);
 					}
 				};
+
+				playlist.Play(musicInfo, onComplete);
 			}
 			else
-				onComplete = () => { };
-
-			Sound.PlayMusicThen(musicInfo, onComplete);
-
-			previousMusic = Sound.CurrentMusic;
+				playlist.Play(musicInfo);
 		}
 
 		[Desc("Stop the current song.")]
 		public void StopMusic()
 		{
-			Sound.StopMusic();
+			playlist.Stop();
 		}
 
 		Action onCompleteFullscreen;

OpenRA.Mods.Common/Widgets/Logic/MusicPlayerLogic.cs

@@ -18,29 +18,24 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 {
 	public class MusicPlayerLogic
 	{
-		readonly Ruleset modRules;
+		readonly ScrollPanelWidget musicList;
+		readonly ScrollItemWidget itemTemplate;
 
-		bool installed;
+		readonly MusicPlaylist musicPlaylist;
 		MusicInfo currentSong = null;
-		MusicInfo[] music;
-		MusicInfo[] random;
-		ScrollPanelWidget musicList;
-
-		ScrollItemWidget itemTemplate;
 
 		[ObjectCreator.UseCtor]
 		public MusicPlayerLogic(Widget widget, Ruleset modRules, World world, Action onExit)
 		{
-			this.modRules = modRules;
-
 			var panel = widget.Get("MUSIC_PANEL");
 
 			musicList = panel.Get<ScrollPanelWidget>("MUSIC_LIST");
 			itemTemplate = musicList.Get<ScrollItemWidget>("MUSIC_TEMPLATE");
+			musicPlaylist = world.WorldActor.Trait<MusicPlaylist>();
 
 			BuildMusicTable();
 
-			Func<bool> noMusic = () => !installed;
+			Func<bool> noMusic = () => !musicPlaylist.IsMusicAvailable;
 			panel.Get("NO_MUSIC_LABEL").IsVisible = noMusic;
 
 			var playButton = panel.Get<ButtonWidget>("BUTTON_PLAY");
@@ -54,15 +49,15 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 			pauseButton.IsVisible = () => Sound.MusicPlaying;
 
 			var stopButton = panel.Get<ButtonWidget>("BUTTON_STOP");
-			stopButton.OnClick = Sound.StopMusic;
+			stopButton.OnClick = () => { musicPlaylist.Stop(); };
 			stopButton.IsDisabled = noMusic;
 
 			var nextButton = panel.Get<ButtonWidget>("BUTTON_NEXT");
-			nextButton.OnClick = () => { currentSong = GetNextSong(); Play(); };
+			nextButton.OnClick = () => { currentSong = musicPlaylist.GetNextSong(); Play(); };
 			nextButton.IsDisabled = noMusic;
 
 			var prevButton = panel.Get<ButtonWidget>("BUTTON_PREV");
-			prevButton.OnClick = () => { currentSong = GetPrevSong(); Play(); };
+			prevButton.OnClick = () => { currentSong = musicPlaylist.GetPrevSong(); Play(); };
 			prevButton.IsDisabled = noMusic;
 
 			var shuffleCheckbox = panel.Get<CheckboxWidget>("SHUFFLE");
@@ -111,11 +106,13 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 
 		public void BuildMusicTable()
 		{
-			music = modRules.InstalledMusic.Select(a => a.Value).ToArray();
-			random = music.Shuffle(Game.CosmeticRandom).ToArray();
-			currentSong = Sound.CurrentMusic;
+			if (!musicPlaylist.IsMusicAvailable)
+				return;
+
+			var music = musicPlaylist.AvailablePlaylist();
+			currentSong = musicPlaylist.CurrentSong();
 			if (currentSong == null && music.Any())
-				currentSong = Game.Settings.Sound.Shuffle ? random.First() : music.First();
+				currentSong = musicPlaylist.GetNextSong();
 
 			musicList.RemoveChildren();
 			foreach (var s in music)
@@ -124,8 +121,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 				if (currentSong == null)
 					currentSong = song;
 
-				// TODO: We leak the currentSong MusicInfo across map load, so compare the Filename instead.
-				var item = ScrollItemWidget.Setup(song.Filename, itemTemplate, () => currentSong.Filename == song.Filename, () => { currentSong = song; Play(); }, () => { });
+				var item = ScrollItemWidget.Setup(song.Filename, itemTemplate, () => currentSong == song, () => { currentSong = song; Play(); }, () => { });
 				item.Get<LabelWidget>("TITLE").GetText = () => song.Title;
 				item.Get<LabelWidget>("LENGTH").GetText = () => SongLengthLabel(song);
 				musicList.AddChild(item);
@@ -133,8 +129,6 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 
 			if (currentSong != null)
 				musicList.ScrollToItem(currentSong.Filename);
-
-			installed = modRules.InstalledMusic.Any();
 		}
 
 		void Play()
@@ -143,38 +137,12 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 				return;
 
 			musicList.ScrollToItem(currentSong.Filename);
-
-			Sound.PlayMusicThen(currentSong, () =>
-			{
-				if (!Game.Settings.Sound.Repeat)
-					currentSong = GetNextSong();
-				Play();
-			});
+			musicPlaylist.Play(currentSong);
 		}
 
 		static string SongLengthLabel(MusicInfo song)
 		{
 			return "{0:D1}:{1:D2}".F(song.Length / 60, song.Length % 60);
 		}
-
-		MusicInfo GetNextSong()
-		{
-			if (!music.Any())
-				return null;
-
-			var songs = Game.Settings.Sound.Shuffle ? random : music;
-			return songs.SkipWhile(m => m != currentSong)
-				.Skip(1).FirstOrDefault() ?? songs.FirstOrDefault();
-		}
-
-		MusicInfo GetPrevSong()
-		{
-			if (!music.Any())
-				return null;
-
-			var songs = Game.Settings.Sound.Shuffle ? random : music;
-			return songs.Reverse().SkipWhile(m => m != currentSong)
-				.Skip(1).FirstOrDefault() ?? songs.Reverse().FirstOrDefault();
-		}
 	}
 }