Playlist Support is functional:

    Allow multiple playlist directories.
    Always add the BeatDrop playlist folder.
    Playlist show in order defined in the playlist file.
    Handle bad or unknown base64 data for now.

SongBrowserPlugin/DataAccess/Playlist.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace SongBrowserPlugin.DataAccess
+{
+    public class Playlist
+    {
+        public String playlistTitle { get; set; }
+        public String playlistAuthor { get; set; }
+        public string image { get; set; }
+        public List<PlaylistSong> songs { get; set; }
+
+        public String playlistPath;
+    }
+}

SongBrowserPlugin/DataAccess/PlaylistReader.cs

@@ -0,0 +1,104 @@
+using SimpleJSON;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+
+namespace SongBrowserPlugin.DataAccess
+{
+    public class PlaylistsReader
+    {
+        private static Logger _log = new Logger("PlaylistReader");
+
+        private List<String> _PlaylistsDirectories = new List<string>();
+
+        private List<Playlist> _CachedPlaylists;
+
+        public List<Playlist> Playlists
+        {
+            get
+            {
+                return _CachedPlaylists;
+            }
+        }
+
+        public PlaylistsReader(String playlistsDirectory)
+        {
+            _PlaylistsDirectories.Add(playlistsDirectory);
+
+            // Hack, add beatdrop location
+            String localAppDataPath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+            String beatDropPlaylistPath = Path.Combine(localAppDataPath, "Programs", "BeatDrop", "playlists");
+
+            _PlaylistsDirectories.Add(beatDropPlaylistPath);
+        }
+
+        public void UpdatePlaylists()
+        {           
+            _CachedPlaylists = new List<Playlist>();
+
+            foreach (String path in _PlaylistsDirectories)
+            {
+                _log.Debug("Reading playlists located at: {0}", path);
+                if (!Directory.Exists(path))
+                {
+                    _log.Info("Playlist path does not exist: {0}", path);
+                    continue;
+                }
+
+                string[] files = Directory.GetFiles(path);
+                foreach (string file in files)
+                {
+                    _log.Debug("Checking file {0}", file);
+                    if (Path.GetExtension(file) == ".json")
+                    {
+                        Playlist p = ParsePlaylist(file);
+                        _CachedPlaylists.Add(p);
+                    }
+                }
+            }
+        }
+
+        public static Playlist ParsePlaylist(String path)
+        {
+            try
+            {
+                if (!File.Exists(path))
+                {
+                    _log.Debug("Playlist file no longer exists: {0}", path);
+                    return null;
+                }
+
+                _log.Debug("Parsing playlist at {0}", path);
+                String json = File.ReadAllText(path);
+                Playlist playlist = new Playlist();
+
+                JSONNode playlistNode = JSON.Parse(json);
+
+                playlist.image = playlistNode["image"];
+                playlist.playlistTitle = playlistNode["playlistTitle"];
+                playlist.playlistAuthor = playlistNode["playlistAuthor"];
+                playlist.songs = new List<PlaylistSong>();
+
+                foreach (JSONNode node in playlistNode["songs"].AsArray)
+                {
+                    PlaylistSong song = new PlaylistSong();
+                    song.key = node["key"];
+                    song.songName = node["songName"];
+
+                    playlist.songs.Add(song);
+                }
+
+                playlist.playlistPath = path;
+                return playlist;
+            }
+            catch (Exception e)
+            {
+                _log.Exception("Exception parsing playlist: ", e);
+            }
+
+            return null;
+        }
+    }
+}

SongBrowserPlugin/DataAccess/PlaylistSong.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace SongBrowserPlugin.DataAccess
+{
+    public class PlaylistSong
+    {
+        public int key { get; set; }
+        public String songName { get; set; }
+    }
+}

SongBrowserPlugin/DataAccess/SongBrowserSettings.cs

@@ -13,10 +13,11 @@ public enum SongSortMode
         Author,
         Favorites,
         Original,
-        Newest,
+        Newest,        
         PlayCount,
         Difficulty,
         Random,
+        Playlist,
         Search
     }
 
@@ -29,7 +30,7 @@ public class SongBrowserSettings
 
         public String currentLevelId = default(String);
         public String currentDirectory = default(String);
-
+        public String currentPlaylistFile = default(String);
 
         [NonSerialized]
         private static Logger Log = new Logger("SongBrowserSettings");

SongBrowserPlugin/Logger.cs

@@ -15,7 +15,7 @@ public enum LogLevel
     public class Logger
     {
         private string loggerName;
-        private LogLevel _LogLevel = LogLevel.Info;
+        private LogLevel _LogLevel = LogLevel.Trace;
         private ConsoleColor _defaultFgColor;
 
         public Logger(string _name)

SongBrowserPlugin/SongBrowserApplication.cs

@@ -156,6 +156,14 @@ public static void InvokeBeatSaberButton(String buttonName)
         /// </summary>
         private void LateUpdate()
         {
+            // playlists
+            if (Input.GetKeyDown(KeyCode.P))
+            {
+                MainMenuViewController mainView = Resources.FindObjectsOfTypeAll<MainMenuViewController>().First();
+                PlaylistFlowCoordinator view = UIBuilder.CreateFlowCoordinator<PlaylistFlowCoordinator>("PlaylistFlowCoordinator");
+                view.Present(mainView);
+            }
+
             // z,x,c,v can be used to get into a song, b will hit continue button after song ends
             if (Input.GetKeyDown(KeyCode.Z))
             {

SongBrowserPlugin/SongBrowserModel.cs

@@ -93,6 +93,7 @@ public class SongBrowserModel
         private Dictionary<string, int> _weights;
         private Dictionary<String, DirectoryNode> _directoryTree;
         private Stack<DirectoryNode> _directoryStack = new Stack<DirectoryNode>();
+
         private GameplayMode _currentGamePlayMode;
 
         /// <summary>
@@ -161,6 +162,9 @@ public String LastSelectedLevelId
             }
         }
 
+        /// <summary>
+        /// Get the last known directory the user visited.
+        /// </summary>
         public String CurrentDirectory
         {
             get
@@ -175,6 +179,30 @@ public String CurrentDirectory
             }
         }
 
+        private Playlist _currentPlaylist;
+
+        /// <summary>
+        /// Manage the current playlist if one exists.
+        /// </summary>
+        public Playlist CurrentPlaylist
+        {
+            get
+            {
+                if (_currentPlaylist == null)
+                {
+                    _currentPlaylist = PlaylistsReader.ParsePlaylist(this._settings.currentPlaylistFile);
+                }
+
+                return _currentPlaylist;
+            }
+
+            set
+            {
+                _settings.currentPlaylistFile = value.playlistPath;
+                _currentPlaylist = value;
+            }
+        }
+
 
         /// <summary>
         /// Constructor.
@@ -453,11 +481,19 @@ private void ProcessSongList()
                 }
             }*/
 
-            Stopwatch stopwatch = Stopwatch.StartNew();
-
-            _log.Debug("Showing songs for directory: {0}", _directoryStack.Peek().Key);
-            List<StandardLevelSO> songList = _directoryStack.Peek().Levels;
+            Stopwatch stopwatch = Stopwatch.StartNew();           
 
+            List<StandardLevelSO> songList = null;
+            if (this._settings.sortMode == SongSortMode.Playlist && this.CurrentPlaylist != null)
+            {                
+                songList = null;
+            }
+            else
+            {
+                _log.Debug("Showing songs for directory: {0}", _directoryStack.Peek().Key);
+                songList = _directoryStack.Peek().Levels;
+            }
+
             switch (_settings.sortMode)
             {
                 case SongSortMode.Favorites:
@@ -484,6 +520,9 @@ private void ProcessSongList()
                 case SongSortMode.Search:
                     SortSearch(songList);
                     break;
+                case SongSortMode.Playlist:
+                    SortPlaylist();
+                    break;
                 case SongSortMode.Default:
                 default:
                     SortSongName(songList);
@@ -675,5 +714,19 @@ private void SortSongName(List<StandardLevelSO> levels)
                 .ThenBy(x => x.songAuthorName)
                 .ToList();
         }
+
+        private void SortPlaylist()
+        {
+            _log.Debug("Showing songs for playlist: {0}", this.CurrentPlaylist);
+            List<String> playlistNameListOrdered = this.CurrentPlaylist.songs.Select(x => x.songName).ToList();
+            Dictionary<String, int> songNameToIndex = playlistNameListOrdered.Select((val, index) => new { Index = index, Value = val }).ToDictionary(i => i.Value, i => i.Index);
+            HashSet<String> songNames = new HashSet<String>(playlistNameListOrdered);
+            SongLoaderPlugin.OverrideClasses.CustomLevelCollectionsForGameplayModes collections = SongLoaderPlugin.SongLoader.Instance.GetPrivateField<SongLoaderPlugin.OverrideClasses.CustomLevelCollectionsForGameplayModes>("_customLevelCollectionsForGameplayModes");
+            List<StandardLevelSO> songList = collections.GetLevels(_currentGamePlayMode).Where(x => songNames.Contains(x.songName)).ToList();
+            _sortedSongs = songList
+                .AsQueryable()
+                .OrderBy(x => songNameToIndex[x.songName])
+                .ToList();
+        }
     }
 }

SongBrowserPlugin/SongBrowserPlugin.csproj

@@ -70,6 +70,9 @@
     <Reference Include="UnityEngine.JSONSerializeModule, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null">
       <HintPath>D:\Games\Steam\SteamApps\common\Beat Saber\Beat Saber_Data\Managed\UnityEngine.JSONSerializeModule.dll</HintPath>
     </Reference>
+    <Reference Include="UnityEngine.Networking">
+      <HintPath>D:\Games\Steam\SteamApps\common\Beat Saber\Beat Saber_Data\Managed\UnityEngine.Networking.dll</HintPath>
+    </Reference>
     <Reference Include="UnityEngine.TextRenderingModule, Version=0.0.0.0, Culture=neutral, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
       <HintPath>D:\Games\Steam\SteamApps\common\Beat Saber\Beat Saber_Data\Managed\UnityEngine.TextRenderingModule.dll</HintPath>
@@ -86,14 +89,32 @@
       <SpecificVersion>False</SpecificVersion>
       <HintPath>D:\Games\Steam\SteamApps\common\Beat Saber\Beat Saber_Data\Managed\UnityEngine.UIModule.dll</HintPath>
     </Reference>
+    <Reference Include="UnityEngine.UnityWebRequestModule, Version=0.0.0.0, Culture=neutral, processorArchitecture=MSIL">
+      <SpecificVersion>False</SpecificVersion>
+      <HintPath>D:\Games\Steam\SteamApps\common\Beat Saber\Beat Saber_Data\Managed\UnityEngine.UnityWebRequestModule.dll</HintPath>
+    </Reference>
+    <Reference Include="UnityEngine.UnityWebRequestWWWModule, Version=0.0.0.0, Culture=neutral, processorArchitecture=MSIL">
+      <SpecificVersion>False</SpecificVersion>
+      <HintPath>D:\Games\Steam\SteamApps\common\Beat Saber\Beat Saber_Data\Managed\UnityEngine.UnityWebRequestWWWModule.dll</HintPath>
+    </Reference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="BeatSaverApi\BeatSaverApi.cs" />
+    <Compile Include="BeatSaverApi\BeatSaverAPIResults.cs" />
+    <Compile Include="DataAccess\Playlist.cs" />
+    <Compile Include="DataAccess\PlaylistReader.cs" />
+    <Compile Include="DataAccess\PlaylistSong.cs" />
     <Compile Include="Logger.cs" />
     <Compile Include="SongBrowserApplication.cs" />
     <Compile Include="Plugin.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="SongBrowserModel.cs" />
     <Compile Include="DataAccess\SongBrowserSettings.cs" />
+    <Compile Include="UI\Playlists\PlaylistDetailViewController.cs" />
+    <Compile Include="UI\Playlists\PlaylistFlowCoordinator.cs" />
+    <Compile Include="UI\Playlists\PlaylistSelectionListViewController.cs" />
+    <Compile Include="UI\Playlists\PlaylistSelectionNavigationController.cs" />
+    <Compile Include="UI\Playlists\PlaylistTableView.cs" />
     <Compile Include="UI\Base64Sprites.cs" />
     <Compile Include="UI\CustomUIKeyboard.cs" />
     <Compile Include="UI\SearchKeyboardViewController.cs" />

SongBrowserPlugin/UI/Base64Sprites.cs

@@ -14,8 +14,24 @@ class Base64Sprites
 
         public static Sprite Base64ToSprite(string base64)
         {
-            Texture2D tex = Base64ToTexture2D(base64);
-            return Sprite.Create(tex, new Rect(0, 0, tex.width, tex.height), (Vector2.one / 2f));
+            if (base64.StartsWith("data:image/png;base64,"))
+            {
+                base64 = base64.Remove(0, "data:image/png;base64,".Length);
+            }
+
+            Sprite s = null;
+            try
+            {
+                Texture2D tex = Base64ToTexture2D(base64);
+                s = Sprite.Create(tex, new Rect(0, 0, tex.width, tex.height), (Vector2.one / 2f));
+            }
+            catch (Exception e)
+            {
+                Console.WriteLine("Exception loading texture from base64 data.");
+                s = null;
+            }
+
+            return s;
         }
 
         public static Texture2D Base64ToTexture2D(string encodedData)