Make downloads happen in BeatmapManager.

osu.Desktop.Tests/Visual/TestCasePlaySongSelect.cs

@@ -32,7 +32,7 @@ namespace osu.Desktop.Tests.Visual
                 backingDatabase.CreateTable<StoreVersion>();
 
                 rulesets = new RulesetStore(backingDatabase);
-                manager = new BeatmapManager(storage, null, backingDatabase, rulesets);
+                manager = new BeatmapManager(storage, null, backingDatabase, rulesets, null);
 
                 for (int i = 0; i < 100; i += 10)
                     manager.Import(createTestBeatmapSet(i));

osu.Game/Beatmaps/BeatmapManager.cs

@@ -20,6 +20,9 @@ using osu.Game.IPC;
 using osu.Game.Overlays.Notifications;
 using osu.Game.Rulesets;
 using SQLite.Net;
+using osu.Game.Online.API.Requests;
+using System.Threading.Tasks;
+using osu.Game.Online.API;
 
 namespace osu.Game.Beatmaps
 {
@@ -63,6 +66,10 @@ namespace osu.Game.Beatmaps
 
         private readonly BeatmapStore beatmaps;
 
+        private readonly APIAccess api;
+
+        private readonly Dictionary<BeatmapSetInfo, DownloadBeatmapSetRequest> downloadsMap;
+
         // ReSharper disable once NotAccessedField.Local (we should keep a reference to this so it is not finalised)
         private BeatmapIPCChannel ipc;
 
@@ -76,7 +83,7 @@ namespace osu.Game.Beatmaps
         /// </summary>
         public Func<Storage> GetStableStorage { private get; set; }
 
-        public BeatmapManager(Storage storage, FileStore files, SQLiteConnection connection, RulesetStore rulesets, IIpcHost importHost = null)
+        public BeatmapManager(Storage storage, FileStore files, SQLiteConnection connection, RulesetStore rulesets, APIAccess api, IIpcHost importHost = null)
         {
             beatmaps = new BeatmapStore(connection);
             beatmaps.BeatmapSetAdded += s => BeatmapSetAdded?.Invoke(s);
@@ -88,9 +95,12 @@ namespace osu.Game.Beatmaps
             this.files = files;
             this.connection = connection;
             this.rulesets = rulesets;
+            this.api = api;
 
             if (importHost != null)
                 ipc = new BeatmapIPCChannel(importHost, this);
+
+            downloadsMap = new Dictionary<BeatmapSetInfo, DownloadBeatmapSetRequest>();
         }
 
         /// <summary>
@@ -177,6 +187,68 @@ namespace osu.Game.Beatmaps
             beatmaps.Add(beatmapSetInfo);
         }
 
+        /// <summary>
+        /// Download a beatmap
+        /// </summary>
+        /// <param name="beatmapSetInfo">The beatmap to be downloaded</param>
+        public DownloadBeatmapSetRequest Download(BeatmapSetInfo beatmapSetInfo)
+        {
+            if (api == null || downloadsMap.ContainsKey(beatmapSetInfo)) return null;
+
+            ProgressNotification downloadNotification = new ProgressNotification
+            {
+                Text = $"Downloading {beatmapSetInfo.Metadata.Artist} - {beatmapSetInfo.Metadata.Title}",
+            };
+
+            var request = new DownloadBeatmapSetRequest(beatmapSetInfo);
+
+            request.DownloadProgressed += progress =>
+            {
+                downloadNotification.State = ProgressNotificationState.Active;
+                downloadNotification.Progress = progress;
+            };
+
+            request.Success += data =>
+            {
+                downloadNotification.State = ProgressNotificationState.Completed;
+
+                using (var stream = new MemoryStream(data))
+                using (var archive = new OszArchiveReader(stream))
+                    Import(archive);
+
+                downloadsMap.Remove(beatmapSetInfo);
+            };
+
+            request.Failure += data =>
+            {
+                downloadNotification.State = ProgressNotificationState.Completed;
+                Logger.Error(data, "Failed to get beatmap download information");
+                downloadsMap.Remove(beatmapSetInfo);
+            };
+
+            downloadNotification.CancelRequested += () =>
+            {
+                Logger.Log("Cancel requested");
+                downloadsMap.Remove(beatmapSetInfo);
+                return true;
+            };
+
+            downloadsMap[beatmapSetInfo] = request;
+            PostNotification?.Invoke(downloadNotification);
+
+            // don't run in the main api queue as this is a long-running task.
+            Task.Run(() => request.Perform(api));
+
+            return request;
+        }
+
+        /// <summary>
+        /// Check if a beatmap is already downloading.
+        /// </summary>
+        /// <param name="beatmap">The <see cref="BeatmapSetInfo"/>to check against.</param>
+        /// <returns>true if a download request already exists, false if it doesn't.</returns>
+        public bool IsDownloading(BeatmapSetInfo beatmap) => downloadsMap.ContainsKey(beatmap);
+
         /// <summary>
         /// Delete a beatmap from the manager.
         /// Is a no-op for already deleted beatmaps.

osu.Game/Online/API/Requests/DownloadBeatmapSetRequest.cs

@@ -0,0 +1,21 @@
+using osu.Game.Beatmaps;
+using System;
+
+namespace osu.Game.Online.API.Requests
+{
+    public class DownloadBeatmapSetRequest : APIDownloadRequest
+    {
+        private readonly BeatmapSetInfo beatmapSet;
+
+        public Action<float> DownloadProgressed;
+
+        public DownloadBeatmapSetRequest(BeatmapSetInfo beatmapSet)
+        {
+            this.beatmapSet = beatmapSet;
+
+            Progress += (current, total) => DownloadProgressed?.Invoke((float) current / total);
+        }
+
+        protected override string Target => $@"beatmapsets/{beatmapSet.OnlineBeatmapSetID}/download";
+    }
+}

osu.Game/OsuGameBase.cs

@@ -106,9 +106,15 @@ namespace osu.Game
 
             connection.CreateTable<StoreVersion>();
 
+            dependencies.Cache(API = new APIAccess
+            {
+                Username = LocalConfig.Get<string>(OsuSetting.Username),
+                Token = LocalConfig.Get<string>(OsuSetting.Token)
+            });
+
             dependencies.Cache(RulesetStore = new RulesetStore(connection));
             dependencies.Cache(FileStore = new FileStore(connection, Host.Storage));
-            dependencies.Cache(BeatmapManager = new BeatmapManager(Host.Storage, FileStore, connection, RulesetStore, Host));
+            dependencies.Cache(BeatmapManager = new BeatmapManager(Host.Storage, FileStore, connection, RulesetStore, API, Host));
             dependencies.Cache(ScoreStore = new ScoreStore(Host.Storage, connection, Host, BeatmapManager, RulesetStore));
             dependencies.Cache(KeyBindingStore = new KeyBindingStore(connection, RulesetStore));
             dependencies.Cache(new OsuColour());
@@ -144,12 +150,6 @@ namespace osu.Game
             Beatmap = new NonNullableBindable<WorkingBeatmap>(defaultBeatmap);
             BeatmapManager.DefaultBeatmap = defaultBeatmap;
 
-            dependencies.Cache(API = new APIAccess
-            {
-                Username = LocalConfig.Get<string>(OsuSetting.Username),
-                Token = LocalConfig.Get<string>(OsuSetting.Token)
-            });
-
             Beatmap.ValueChanged += b =>
             {
                 // compare to last beatmap as sometimes the two may share a track representation (optimisation, see WorkingBeatmap.TransferTo)

osu.Game/Overlays/Direct/DirectPanel.cs

@@ -115,23 +115,8 @@ namespace osu.Game.Overlays.Direct
             base.OnHoverLost(state);
         }
 
-        // this should eventually be moved to a more central place, like BeatmapManager.
-        private DownloadBeatmapSetRequest downloadRequest;
-
         protected void StartDownload()
         {
-            if (api == null) return;
-
-            // we already have an active download running.
-            if (downloadRequest != null)
-            {
-                content.MoveToX(-5, 50, Easing.OutSine).Then()
-                       .MoveToX(5, 100, Easing.InOutSine).Then()
-                       .MoveToX(-5, 100, Easing.InOutSine).Then()
-                       .MoveToX(0, 50, Easing.InSine).Then();
-                return;
-            }
-
             if (!api.LocalUser.Value.IsSupporter)
             {
                 notifications.Post(new SimpleNotification
@@ -142,25 +127,28 @@ namespace osu.Game.Overlays.Direct
                 return;
             }
 
+            // we already have an active download running.
+            if (beatmaps.IsDownloading(SetInfo))
+            {
+                content.MoveToX(-5, 50, Easing.OutSine).Then()
+                       .MoveToX(5, 100, Easing.InOutSine).Then()
+                       .MoveToX(-5, 100, Easing.InOutSine).Then()
+                       .MoveToX(0, 50, Easing.InSine).Then();
+                return;
+            }
+
+            var downloadRequest = beatmaps.Download(SetInfo);
+
             progressBar.FadeIn(400, Easing.OutQuint);
             progressBar.ResizeHeightTo(4, 400, Easing.OutQuint);
 
             progressBar.Current.Value = 0;
 
-            ProgressNotification downloadNotification = new ProgressNotification
-            {
-                Text = $"Downloading {SetInfo.Metadata.Artist} - {SetInfo.Metadata.Title}",
-            };
-
-            downloadRequest = new DownloadBeatmapSetRequest(SetInfo);
             downloadRequest.Failure += e =>
             {
                 progressBar.Current.Value = 0;
                 progressBar.FadeOut(500);
-                downloadNotification.State = ProgressNotificationState.Completed;
                 Logger.Error(e, "Failed to get beatmap download information");
-
-                downloadRequest = null;
             };
 
             downloadRequest.Progress += (current, total) =>
@@ -169,45 +157,13 @@ namespace osu.Game.Overlays.Direct
 
                 progressBar.Current.Value = progress;
 
-                downloadNotification.State = ProgressNotificationState.Active;
-                downloadNotification.Progress = progress;
             };
 
             downloadRequest.Success += data =>
             {
                 progressBar.Current.Value = 1;
                 progressBar.FadeOut(500);
-
-                downloadNotification.State = ProgressNotificationState.Completed;
-
-                using (var stream = new MemoryStream(data))
-                using (var archive = new OszArchiveReader(stream))
-                    beatmaps.Import(archive);
             };
-
-            downloadNotification.CancelRequested += () =>
-            {
-                downloadRequest.Cancel();
-                downloadRequest = null;
-                return true;
-            };
-
-            notifications.Post(downloadNotification);
-
-            // don't run in the main api queue as this is a long-running task.
-            Task.Run(() => downloadRequest.Perform(api));
-        }
-
-        public class DownloadBeatmapSetRequest : APIDownloadRequest
-        {
-            private readonly BeatmapSetInfo beatmapSet;
-
-            public DownloadBeatmapSetRequest(BeatmapSetInfo beatmapSet)
-            {
-                this.beatmapSet = beatmapSet;
-            }
-
-            protected override string Target => $@"beatmapsets/{beatmapSet.OnlineBeatmapSetID}/download";
         }
 
         protected override void LoadComplete()

osu.Game/osu.Game.csproj

@@ -98,6 +98,7 @@
     <Compile Include="Input\Bindings\GlobalKeyBindingInputManager.cs" />
     <Compile Include="IO\FileStore.cs" />
     <Compile Include="IO\FileInfo.cs" />
+    <Compile Include="Online\API\Requests\DownloadBeatmapSetRequest.cs" />
     <Compile Include="Online\API\Requests\GetUsersRequest.cs" />
     <Compile Include="Online\API\Requests\PostMessageRequest.cs" />
     <Compile Include="Online\Chat\ErrorMessage.cs" />