Update to 0.16.0-alpha

We use the RawImageDataProvider here to pass the already downloaded
image onto this transform, to avoid fetching it from MPD again. The
180x180 size artwork is plenty big enough to use as source for the 32x32
queue/dragged song artwork.

Persephone.xcodeproj/project.pbxproj

@@ -53,9 +53,11 @@
 		E44051A0227BB0AB0090CD6F /* UIState.swift in Sources */ = {isa = PBXBuildFile; fileRef = E440519F227BB0AB0090CD6F /* UIState.swift */; };
 		E442CCCD2347E73C00004E0C /* Artist.swift in Sources */ = {isa = PBXBuildFile; fileRef = E442CCCC2347E73C00004E0C /* Artist.swift */; };
 		E450AD7E222620A10091BED3 /* Album.swift in Sources */ = {isa = PBXBuildFile; fileRef = E450AD7D222620A10091BED3 /* Album.swift */; };
-		E450AD9522262DF10091BED3 /* CoverArtQueue.swift in Sources */ = {isa = PBXBuildFile; fileRef = E450AD9422262DF10091BED3 /* CoverArtQueue.swift */; };
 		E451E36B22BD214D008BE9B2 /* DraggedSongType.swift in Sources */ = {isa = PBXBuildFile; fileRef = E451E36A22BD214D008BE9B2 /* DraggedSongType.swift */; };
 		E451E36E22BD2501008BE9B2 /* DraggedSong.swift in Sources */ = {isa = PBXBuildFile; fileRef = E451E36C22BD23DB008BE9B2 /* DraggedSong.swift */; };
+		E453825223FA0186007F6BFC /* VolumeControlView.swift in Sources */ = {isa = PBXBuildFile; fileRef = E453825023FA0186007F6BFC /* VolumeControlView.swift */; };
+		E453825323FA0186007F6BFC /* VolumeControlView.xib in Resources */ = {isa = PBXBuildFile; fileRef = E453825123FA0186007F6BFC /* VolumeControlView.xib */; };
+		E453825523FA347C007F6BFC /* MPDClient+Mixer.swift in Sources */ = {isa = PBXBuildFile; fileRef = E453825423FA347C007F6BFC /* MPDClient+Mixer.swift */; };
 		E45878382296173C00586A1C /* AlbumDetailSongRowView.swift in Sources */ = {isa = PBXBuildFile; fileRef = E45878372296173C00586A1C /* AlbumDetailSongRowView.swift */; };
 		E45962C62241A78500FC1A1E /* MPDCommand.swift in Sources */ = {isa = PBXBuildFile; fileRef = E45962C52241A78500FC1A1E /* MPDCommand.swift */; };
 		E45E4FDA22515D87004B537F /* CHANGELOG.md in Resources */ = {isa = PBXBuildFile; fileRef = E45E4FD722515D87004B537F /* CHANGELOG.md */; };
@@ -81,6 +83,8 @@
 		E4A642DA22090CBE00067D21 /* MPDStatus.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4A642D922090CBE00067D21 /* MPDStatus.swift */; };
 		E4A83BEF2221F8CF0098FED6 /* CoverArtPrefsController.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4A83BEE2221F8CF0098FED6 /* CoverArtPrefsController.swift */; };
 		E4A83BF12221FAA00098FED6 /* PreferencesViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4A83BF02221FAA00098FED6 /* PreferencesViewController.swift */; };
+		E4B079C723E5E0AD0044B6D3 /* libmpdclient.2.dylib in Frameworks */ = {isa = PBXBuildFile; fileRef = E41B22BF21FB6BBA00D544F6 /* libmpdclient.2.dylib */; };
+		E4B079C823E5E0AD0044B6D3 /* libmpdclient.2.dylib in Embed Libraries */ = {isa = PBXBuildFile; fileRef = E41B22BF21FB6BBA00D544F6 /* libmpdclient.2.dylib */; settings = {ATTRIBUTES = (CodeSignOnCopy, ); }; };
 		E4B11B53226928F20075461B /* AppState.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4B11B52226928F20075461B /* AppState.swift */; };
 		E4B11B61226A4C000075461B /* PlayerReducer.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4B11B60226A4BFF0075461B /* PlayerReducer.swift */; };
 		E4B11B63226A4C510075461B /* AppReducer.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4B11B62226A4C510075461B /* AppReducer.swift */; };
@@ -90,8 +94,6 @@
 		E4B11B73226A6C770075461B /* TrackTimer.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4B11B72226A6C770075461B /* TrackTimer.swift */; };
 		E4B11B75226CC4D30075461B /* QueueReducer.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4B11B74226CC4D30075461B /* QueueReducer.swift */; };
 		E4B11B79226D346B0075461B /* AlbumListReducer.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4B11B78226D346B0075461B /* AlbumListReducer.swift */; };
-		E4B11BA62274E44A0075461B /* libmpdclient.2.dylib in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = E41B22BF21FB6BBA00D544F6 /* libmpdclient.2.dylib */; settings = {ATTRIBUTES = (CodeSignOnCopy, ); }; };
-		E4B11BA72274E4500075461B /* libmpdclient.2.dylib in Frameworks */ = {isa = PBXBuildFile; fileRef = E41B22BF21FB6BBA00D544F6 /* libmpdclient.2.dylib */; };
 		E4B11BA92274EDE30075461B /* Loading.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4B11BA82274EDE30075461B /* Loading.swift */; };
 		E4B11BB62275374B0075461B /* UserNotificationsController.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4B11BB52275374B0075461B /* UserNotificationsController.swift */; };
 		E4B11BB8227538FA0075461B /* CurrentCoverArtView.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4B11BB7227538FA0075461B /* CurrentCoverArtView.swift */; };
@@ -100,11 +102,14 @@
 		E4B11BC22275EE410075461B /* AlbumListActions.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4B11BC12275EE410075461B /* AlbumListActions.swift */; };
 		E4B3DF6523D66A4400728F6B /* QueueSongCoverView.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4B3DF6423D66A4400728F6B /* QueueSongCoverView.swift */; };
 		E4B5AE7E22F4C49600CCEC65 /* MPDServerDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4B5AE7D22F4C49600CCEC65 /* MPDServerDelegate.swift */; };
+		E4BB7F8F23E5E7BC00906E2F /* MPDAlbumArtImageDataProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4BB7F8E23E5E7BC00906E2F /* MPDAlbumArtImageDataProvider.swift */; };
+		E4BB7F9323E9150A00906E2F /* CoverArtService.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4BB7F9223E9150A00906E2F /* CoverArtService.swift */; };
 		E4BBD2F323357C0700702C16 /* ArtistListState.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4BBD2F223357C0700702C16 /* ArtistListState.swift */; };
 		E4C8B53C22342005009A20F3 /* PreferencesWindowController.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4C8B53B22342005009A20F3 /* PreferencesWindowController.swift */; };
 		E4C8B53E22349002009A20F3 /* MPDIdle.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4C8B53D22349002009A20F3 /* MPDIdle.swift */; };
 		E4D3BFA622B419C000C56F48 /* QueueViewController+NSOutlineViewDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4D3BFA522B419C000C56F48 /* QueueViewController+NSOutlineViewDelegate.swift */; };
 		E4DA820623D6236200C1EE58 /* NSSize.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4DA820523D6236200C1EE58 /* NSSize.swift */; };
+		E4DCCFAE23E4DB5D009A8113 /* MPDClientWrapper.c in Sources */ = {isa = PBXBuildFile; fileRef = E4DCCFAD23E4DB5D009A8113 /* MPDClientWrapper.c */; };
 		E4E7A6AD22AAAF98006D566C /* AlbumDetailView+NSTableViewDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4E7A6AC22AAAF98006D566C /* AlbumDetailView+NSTableViewDelegate.swift */; };
 		E4E8CC902204EC7F0024217A /* Delegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4E8CC8F2204EC7F0024217A /* Delegate.swift */; };
 		E4E8CC922204F4B80024217A /* QueueViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4E8CC912204F4B80024217A /* QueueViewController.swift */; };
@@ -151,15 +156,15 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
-		E4B11BA52274E43B0075461B /* Embed Frameworks */ = {
+		E4B079C923E5E0AD0044B6D3 /* Embed Libraries */ = {
 			isa = PBXCopyFilesBuildPhase;
 			buildActionMask = 2147483647;
 			dstPath = "";
 			dstSubfolderSpec = 10;
 			files = (
-				E4B11BA62274E44A0075461B /* libmpdclient.2.dylib in Embed Frameworks */,
+				E4B079C823E5E0AD0044B6D3 /* libmpdclient.2.dylib in Embed Libraries */,
 			);
-			name = "Embed Frameworks";
+			name = "Embed Libraries";
 			runOnlyForDeploymentPostprocessing = 0;
 		};
 /* End PBXCopyFilesBuildPhase section */
@@ -254,10 +259,12 @@
 		E440519F227BB0AB0090CD6F /* UIState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UIState.swift; sourceTree = "<group>"; };
 		E442CCCC2347E73C00004E0C /* Artist.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Artist.swift; sourceTree = "<group>"; };
 		E450AD7D222620A10091BED3 /* Album.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Album.swift; sourceTree = "<group>"; };
-		E450AD9422262DF10091BED3 /* CoverArtQueue.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CoverArtQueue.swift; sourceTree = "<group>"; };
 		E450AD9E2229B9BC0091BED3 /* PersephoneBridgingHeader.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = PersephoneBridgingHeader.h; sourceTree = "<group>"; };
 		E451E36A22BD214D008BE9B2 /* DraggedSongType.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DraggedSongType.swift; sourceTree = "<group>"; };
 		E451E36C22BD23DB008BE9B2 /* DraggedSong.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DraggedSong.swift; sourceTree = "<group>"; };
+		E453825023FA0186007F6BFC /* VolumeControlView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = VolumeControlView.swift; sourceTree = "<group>"; };
+		E453825123FA0186007F6BFC /* VolumeControlView.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; path = VolumeControlView.xib; sourceTree = "<group>"; };
+		E453825423FA347C007F6BFC /* MPDClient+Mixer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "MPDClient+Mixer.swift"; sourceTree = "<group>"; };
 		E45878372296173C00586A1C /* AlbumDetailSongRowView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AlbumDetailSongRowView.swift; sourceTree = "<group>"; };
 		E45962C52241A78500FC1A1E /* MPDCommand.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MPDCommand.swift; sourceTree = "<group>"; };
 		E45E4FD722515D87004B537F /* CHANGELOG.md */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = net.daringfireball.markdown; path = CHANGELOG.md; sourceTree = SOURCE_ROOT; };
@@ -294,11 +301,16 @@
 		E4B11BC12275EE410075461B /* AlbumListActions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AlbumListActions.swift; sourceTree = "<group>"; };
 		E4B3DF6423D66A4400728F6B /* QueueSongCoverView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = QueueSongCoverView.swift; sourceTree = "<group>"; };
 		E4B5AE7D22F4C49600CCEC65 /* MPDServerDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MPDServerDelegate.swift; sourceTree = "<group>"; };
+		E4BB7F8E23E5E7BC00906E2F /* MPDAlbumArtImageDataProvider.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MPDAlbumArtImageDataProvider.swift; sourceTree = "<group>"; };
+		E4BB7F9223E9150A00906E2F /* CoverArtService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CoverArtService.swift; sourceTree = "<group>"; };
 		E4BBD2F223357C0700702C16 /* ArtistListState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ArtistListState.swift; sourceTree = "<group>"; };
 		E4C8B53B22342005009A20F3 /* PreferencesWindowController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PreferencesWindowController.swift; sourceTree = "<group>"; };
 		E4C8B53D22349002009A20F3 /* MPDIdle.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MPDIdle.swift; sourceTree = "<group>"; };
 		E4D3BFA522B419C000C56F48 /* QueueViewController+NSOutlineViewDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "QueueViewController+NSOutlineViewDelegate.swift"; sourceTree = "<group>"; };
 		E4DA820523D6236200C1EE58 /* NSSize.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NSSize.swift; sourceTree = "<group>"; };
+		E4DCCFAB23E4DB5D009A8113 /* Persephone-Bridging-Header.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "Persephone-Bridging-Header.h"; sourceTree = "<group>"; };
+		E4DCCFAC23E4DB5D009A8113 /* MPDClientWrapper.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = MPDClientWrapper.h; sourceTree = "<group>"; };
+		E4DCCFAD23E4DB5D009A8113 /* MPDClientWrapper.c */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.c; path = MPDClientWrapper.c; sourceTree = "<group>"; };
 		E4E7A6AC22AAAF98006D566C /* AlbumDetailView+NSTableViewDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "AlbumDetailView+NSTableViewDelegate.swift"; sourceTree = "<group>"; };
 		E4E8CC8F2204EC7F0024217A /* Delegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Delegate.swift; sourceTree = "<group>"; };
 		E4E8CC912204F4B80024217A /* QueueViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = QueueViewController.swift; sourceTree = "<group>"; };
@@ -322,12 +334,12 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
-				E4B11BA72274E4500075461B /* libmpdclient.2.dylib in Frameworks */,
 				E49A5485233E5ADC00EED353 /* Differ in Frameworks */,
 				E4677C48233E60E70041474F /* MediaKeyTap in Frameworks */,
 				E43BECA0238835DC00CAF1EB /* Kingfisher in Frameworks */,
 				E49A548E233E5B6000EED353 /* SwiftyJSON in Frameworks */,
 				E4E96D13233E630800AFD36F /* PMKFoundation in Frameworks */,
+				E4B079C723E5E0AD0044B6D3 /* libmpdclient.2.dylib in Frameworks */,
 				E49A5482233E580800EED353 /* PromiseKit in Frameworks */,
 				E49A548B233E5B2D00EED353 /* CryptoSwift in Frameworks */,
 				E49A5488233E5B0000EED353 /* ReSwift in Frameworks */,
@@ -387,7 +399,6 @@
 				E40786242110CE70006887B1 /* Info.plist */,
 				E4F6B461221E124700ACF42A /* Models */,
 				E4A642DB220912FA00067D21 /* MPDClient */,
-				E450AD8922262B420091BED3 /* Operations */,
 				E40786252110CE70006887B1 /* Persephone.entitlements */,
 				E450AD9E2229B9BC0091BED3 /* PersephoneBridgingHeader.h */,
 				E4A83BF2222207BE0098FED6 /* Services */,
@@ -441,11 +452,15 @@
 				E42410B52241B956005ED6DF /* MPDClient+Database.swift */,
 				E41E5304223BFB0700173814 /* MPDClient+Error.swift */,
 				E41E5302223BF9C300173814 /* MPDClient+Idle.swift */,
+				E453825423FA347C007F6BFC /* MPDClient+Mixer.swift */,
 				E41E5300223BF99300173814 /* MPDClient+Queue.swift */,
 				E42A4D5022E2167E001C6CAD /* MPDClient+Songs.swift */,
-				E408D3BD220E03EE0006D9BE /* RawRepresentable.swift */,
 				E41E5306223C019100173814 /* MPDClient+Status.swift */,
 				E41E52FE223BF95E00173814 /* MPDClient+Transport.swift */,
+				E4DCCFAD23E4DB5D009A8113 /* MPDClientWrapper.c */,
+				E4DCCFAC23E4DB5D009A8113 /* MPDClientWrapper.h */,
+				E4DCCFAB23E4DB5D009A8113 /* Persephone-Bridging-Header.h */,
+				E408D3BD220E03EE0006D9BE /* RawRepresentable.swift */,
 			);
 			path = Extensions;
 			sourceTree = "<group>";
@@ -512,6 +527,7 @@
 		E442CCC42347D5B900004E0C /* Components */ = {
 			isa = PBXGroup;
 			children = (
+				E453824D23F9F700007F6BFC /* VolumeControl */,
 				E442CCCB2347D77A00004E0C /* Browser */,
 				E4A83BEC2221F5DD0098FED6 /* Preferences */,
 				E442CCC62347D5E700004E0C /* Queue */,
@@ -574,6 +590,7 @@
 		E442CCC92347D6FD00004E0C /* Shared */ = {
 			isa = PBXGroup;
 			children = (
+				E4BB7F8D23E5E7A300906E2F /* ImageDataProviders */,
 				E4E13C2C2350D8CB00092A6E /* Layouts */,
 				E408D3B7220DE8CC0006D9BE /* Extensions */,
 				E489E3A222B9D31800CA8CBD /* DraggedSongView.swift */,
@@ -594,12 +611,13 @@
 			path = Browser;
 			sourceTree = "<group>";
 		};
-		E450AD8922262B420091BED3 /* Operations */ = {
+		E453824D23F9F700007F6BFC /* VolumeControl */ = {
 			isa = PBXGroup;
 			children = (
-				E450AD9422262DF10091BED3 /* CoverArtQueue.swift */,
+				E453825023FA0186007F6BFC /* VolumeControlView.swift */,
+				E453825123FA0186007F6BFC /* VolumeControlView.xib */,
 			);
-			path = Operations;
+			path = VolumeControl;
 			sourceTree = "<group>";
 		};
 		E4A642DB220912FA00067D21 /* MPDClient */ = {
@@ -628,6 +646,7 @@
 			isa = PBXGroup;
 			children = (
 				E439109722640213002982E9 /* SongNotifierService.swift */,
+				E4BB7F9223E9150A00906E2F /* CoverArtService.swift */,
 			);
 			path = Services;
 			sourceTree = "<group>";
@@ -675,6 +694,14 @@
 			path = Actions;
 			sourceTree = "<group>";
 		};
+		E4BB7F8D23E5E7A300906E2F /* ImageDataProviders */ = {
+			isa = PBXGroup;
+			children = (
+				E4BB7F8E23E5E7BC00906E2F /* MPDAlbumArtImageDataProvider.swift */,
+			);
+			path = ImageDataProviders;
+			sourceTree = "<group>";
+		};
 		E4D1B594220BA2490026F233 /* Models */ = {
 			isa = PBXGroup;
 			children = (
@@ -735,7 +762,7 @@
 				E40786162110CE6E006887B1 /* Resources */,
 				E42A98F122430936004D8180 /* ShellScript */,
 				E421AC9B221F7319008B2449 /* CopyFiles */,
-				E4B11BA52274E43B0075461B /* Embed Frameworks */,
+				E4B079C923E5E0AD0044B6D3 /* Embed Libraries */,
 			);
 			buildRules = (
 			);
@@ -804,7 +831,7 @@
 				TargetAttributes = {
 					E40786172110CE6E006887B1 = {
 						CreatedOnToolsVersion = 9.4.1;
-						LastSwiftMigration = 1020;
+						LastSwiftMigration = 1130;
 						SystemCapabilities = {
 							com.apple.HardenedRuntime = {
 								enabled = 1;
@@ -863,6 +890,7 @@
 			files = (
 				E45E4FDB22515D87004B537F /* Brewfile in Resources */,
 				E42A8F3B22176D6400A13ED9 /* LICENSE.md in Resources */,
+				E453825323FA0186007F6BFC /* VolumeControlView.xib in Resources */,
 				E45E4FDA22515D87004B537F /* CHANGELOG.md in Resources */,
 				E43B67AB22909793007DCF55 /* AlbumDetailView.xib in Resources */,
 				E489E3A522B9D31800CA8CBD /* DraggedSongView.xib in Resources */,
@@ -933,13 +961,14 @@
 				E4B11B63226A4C510075461B /* AppReducer.swift in Sources */,
 				E41E5307223C019100173814 /* MPDClient+Status.swift in Sources */,
 				E442CCCD2347E73C00004E0C /* Artist.swift in Sources */,
+				E4DCCFAE23E4DB5D009A8113 /* MPDClientWrapper.c in Sources */,
 				E41E530B223C033700173814 /* MPDClient+Album.swift in Sources */,
 				E42410B62241B956005ED6DF /* MPDClient+Database.swift in Sources */,
+				E4BB7F8F23E5E7BC00906E2F /* MPDAlbumArtImageDataProvider.swift in Sources */,
 				E4235640228623D2001216D6 /* QueueSongInfoView.swift in Sources */,
 				E451E36E22BD2501008BE9B2 /* DraggedSong.swift in Sources */,
 				E4A642DA22090CBE00067D21 /* MPDStatus.swift in Sources */,
 				E4B11BC02275EE150075461B /* QueueActions.swift in Sources */,
-				E450AD9522262DF10091BED3 /* CoverArtQueue.swift in Sources */,
 				E43B67AD229194CD007DCF55 /* AlbumTracksDataSource.swift in Sources */,
 				E41E52FD223BF87300173814 /* MPDClient+Connection.swift in Sources */,
 				E450AD7E222620A10091BED3 /* Album.swift in Sources */,
@@ -968,6 +997,7 @@
 				E419E2872249B96600216A8C /* Song.swift in Sources */,
 				E451E36B22BD214D008BE9B2 /* DraggedSongType.swift in Sources */,
 				E4BBD2F323357C0700702C16 /* ArtistListState.swift in Sources */,
+				E453825223FA0186007F6BFC /* VolumeControlView.swift in Sources */,
 				E44051A0227BB0AB0090CD6F /* UIState.swift in Sources */,
 				E4FF718E2276010E00D4C412 /* PreferencesState.swift in Sources */,
 				E439109822640213002982E9 /* SongNotifierService.swift in Sources */,
@@ -978,6 +1008,7 @@
 				E4F26F7923411B1500D45FF9 /* ArtistReducer.swift in Sources */,
 				E4B11B73226A6C770075461B /* TrackTimer.swift in Sources */,
 				E44051942278765A0090CD6F /* App.swift in Sources */,
+				E4BB7F9323E9150A00906E2F /* CoverArtService.swift in Sources */,
 				E4B11B79226D346B0075461B /* AlbumListReducer.swift in Sources */,
 				E47E2FE52220AA0700F747E6 /* FlexibleGridViewLayout.swift in Sources */,
 				E41E52FF223BF95E00173814 /* MPDClient+Transport.swift in Sources */,
@@ -985,6 +1016,7 @@
 				E47E2FD122205C4600F747E6 /* MainSplitViewController.swift in Sources */,
 				E4B5AE7E22F4C49600CCEC65 /* MPDServerDelegate.swift in Sources */,
 				E4B11BB8227538FA0075461B /* CurrentCoverArtView.swift in Sources */,
+				E453825523FA347C007F6BFC /* MPDClient+Mixer.swift in Sources */,
 				E4E8CC9A22075D370024217A /* MPDSong.swift in Sources */,
 				E41EA46C221636AF0068EF46 /* GeneralPrefsViewController.swift in Sources */,
 				E4E8CC902204EC7F0024217A /* Delegate.swift in Sources */,
@@ -1173,6 +1205,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
+				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_IDENTITY = "Apple Development";
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
@@ -1188,10 +1221,12 @@
 					"$(inherited)",
 					"$(PROJECT_DIR)/libmpdclient/output",
 				);
-				MARKETING_VERSION = "0.15.2-alpha";
+				MARKETING_VERSION = "0.16.0-alpha";
 				PRODUCT_BUNDLE_IDENTIFIER = me.danbarber.Persephone;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE_SPECIFIER = "";
+				SWIFT_OBJC_BRIDGING_HEADER = "Persephone/MPDClient/Extensions/Persephone-Bridging-Header.h";
+				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
 				SWIFT_VERSION = 5.0;
 				SYSTEM_HEADER_SEARCH_PATHS = Persephone/include;
 				USER_HEADER_SEARCH_PATHS = libmpdclient/output;
@@ -1202,6 +1237,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
+				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_IDENTITY = "Apple Development";
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
@@ -1217,10 +1253,11 @@
 					"$(inherited)",
 					"$(PROJECT_DIR)/libmpdclient/output",
 				);
-				MARKETING_VERSION = "0.15.2-alpha";
+				MARKETING_VERSION = "0.16.0-alpha";
 				PRODUCT_BUNDLE_IDENTIFIER = me.danbarber.Persephone;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE_SPECIFIER = "";
+				SWIFT_OBJC_BRIDGING_HEADER = "Persephone/MPDClient/Extensions/Persephone-Bridging-Header.h";
 				SWIFT_VERSION = 5.0;
 				SYSTEM_HEADER_SEARCH_PATHS = Persephone/include;
 				USER_HEADER_SEARCH_PATHS = libmpdclient/output;

Persephone.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -6,8 +6,8 @@
         "repositoryURL": "https://github.com/krzyzanowskim/CryptoSwift",
         "state": {
           "branch": null,
-          "revision": "3a2acbb32ab68215ee1596ee6004da8e90c3721b",
-          "version": "1.0.0"
+          "revision": "a44caef0550c346e0ab9172f7c9a3852c1833599",
+          "version": "1.3.0"
         }
       },
       {
@@ -15,8 +15,8 @@
         "repositoryURL": "https://github.com/tonyarnold/Differ",
         "state": {
           "branch": null,
-          "revision": "e2cca36e7258dd8add88ae46b5ea56509b066e21",
-          "version": "1.4.3"
+          "revision": "dd5d4bfb1c27012d4790e877b29847d2ab9d989b",
+          "version": "1.4.4"
         }
       },
       {
@@ -24,8 +24,8 @@
         "repositoryURL": "https://github.com/PromiseKit/Foundation",
         "state": {
           "branch": null,
-          "revision": "ee06d95342a5007de2fffd898f4f35de026842ac",
-          "version": "3.3.3"
+          "revision": "1a276e598dac59489ed904887e0740fa75e571e0",
+          "version": "3.3.4"
         }
       },
       {
@@ -33,8 +33,8 @@
         "repositoryURL": "https://github.com/onevcat/Kingfisher.git",
         "state": {
           "branch": null,
-          "revision": "8ef6ca8b1b767ac2400762ed2f2bf75ddea3de5b",
-          "version": "5.10.1"
+          "revision": "44bfa76787a0f07e4d5ae3304e9d4f631fd519bd",
+          "version": "5.13.0"
         }
       },
       {
@@ -51,8 +51,8 @@
         "repositoryURL": "https://github.com/mxcl/PromiseKit",
         "state": {
           "branch": null,
-          "revision": "4d8d1287d2e50c53a9f8430ffe88925292838c57",
-          "version": "6.11.0"
+          "revision": "f14f16cc2602afec1030e4f492100d6d43dca544",
+          "version": "6.13.1"
         }
       },
       {

Persephone.xcodeproj/xcshareddata/xcschemes/Persephone.xcscheme

@@ -27,6 +27,15 @@
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       shouldUseLaunchSchemeArgsEnv = "YES">
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "E40786172110CE6E006887B1"
+            BuildableName = "Persephone.app"
+            BlueprintName = "Persephone"
+            ReferencedContainer = "container:Persephone.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
       <Testables>
          <TestableReference
             skipped = "NO">
@@ -49,17 +58,6 @@
             </BuildableReference>
          </TestableReference>
       </Testables>
-      <MacroExpansion>
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "E40786172110CE6E006887B1"
-            BuildableName = "Persephone.app"
-            BlueprintName = "Persephone"
-            ReferencedContainer = "container:Persephone.xcodeproj">
-         </BuildableReference>
-      </MacroExpansion>
-      <AdditionalOptions>
-      </AdditionalOptions>
    </TestAction>
    <LaunchAction
       buildConfiguration = "Debug"
@@ -81,8 +79,6 @@
             ReferencedContainer = "container:Persephone.xcodeproj">
          </BuildableReference>
       </BuildableProductRunnable>
-      <AdditionalOptions>
-      </AdditionalOptions>
    </LaunchAction>
    <ProfileAction
       buildConfiguration = "Release"

Persephone/Assets.xcassets/speakerDisabled.imageset/Contents.json

@@ -0,0 +1,25 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "speakerDisabled.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "speakerDisabled@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  },
+  "properties" : {
+    "template-rendering-intent" : "template"
+  }
+}

Persephone/Assets.xcassets/speakerHigh.imageset/Contents.json

@@ -0,0 +1,25 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "speakerHigh.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "speakerHigh@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  },
+  "properties" : {
+    "template-rendering-intent" : "template"
+  }
+}

Persephone/Assets.xcassets/speakerLow.imageset/Contents.json

@@ -0,0 +1,25 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "speakerLow.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "speakerLow@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  },
+  "properties" : {
+    "template-rendering-intent" : "template"
+  }
+}

Persephone/Assets.xcassets/speakerMid.imageset/Contents.json

@@ -0,0 +1,25 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "speakerMid.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "speakerMid@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  },
+  "properties" : {
+    "template-rendering-intent" : "template"
+  }
+}

Persephone/Assets.xcassets/speakerOff.imageset/Contents.json

@@ -0,0 +1,25 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "speakerOff.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "speakerOff@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  },
+  "properties" : {
+    "template-rendering-intent" : "template"
+  }
+}

Persephone/Components/Browser/Album Browser/AlbumViewItem.swift

@@ -56,10 +56,14 @@ class AlbumViewItem: NSCollectionViewItem {
   }
 
   func setAlbumCover(_ album: Album) {
-    guard let imagePath = album.coverArtFilePath else { return }
+    guard let song = album.mpdAlbum.firstSong
+      else { return }
+
+    let provider = MPDAlbumArtImageDataProvider(
+      songUri: song.uriString,
+      cacheKey: album.hash
+    )
 
-    let imageURL = URL(fileURLWithPath: imagePath)
-    let provider = LocalFileImageDataProvider(fileURL: imageURL)
     albumCoverView.kf.setImage(
       with: .provider(provider),
       placeholder: NSImage.defaultCoverArt,
@@ -67,7 +71,34 @@ class AlbumViewItem: NSCollectionViewItem {
         .processor(DownsamplingImageProcessor(size: .albumListCoverSize)),
         .scaleFactor(2),
       ]
-    )
+    ) { result in
+      switch result {
+      case .success(let imageResult):
+        guard let imageData = imageResult.image.tiffRepresentation
+          else { return }
+        
+        let rawProvider = RawImageDataProvider(
+          data: imageData,
+          cacheKey: album.hash
+        )
+        
+        self.cacheSmallCover(provider: rawProvider)
+
+      case .failure(_):
+        break
+      }
+    }
+  }
+  
+  func cacheSmallCover(provider: ImageDataProvider) {
+    _ = KingfisherManager.shared.retrieveImage(
+      with: .provider(provider),
+      options: [
+        .memoryCacheExpiration(.never),
+        .processor(DownsamplingImageProcessor(size: .queueSongCoverSize)),
+        .scaleFactor(2),
+      ]
+    ) { result in }
   }
 
   func setAppearance(selected isSelected: Bool) {
@@ -88,6 +119,18 @@ class AlbumViewItem: NSCollectionViewItem {
       boxLayer.backgroundColor = albumCoverBox.layer?.borderColor
     }
   }
+  
+  func refreshAlbumArt() {
+    guard let album = album,
+      let mpdSong = album.mpdAlbum.firstSong
+      else { return }
+      
+    let song = Song(mpdSong: mpdSong)
+    
+    CoverArtService(song: song).refresh {
+      self.setAlbumCover(album)
+    }
+  }
 
   @IBAction func showAlbumDetail(_ sender: NSButton) {
     guard let album = album else { return }
@@ -121,4 +164,8 @@ class AlbumViewItem: NSCollectionViewItem {
 
     App.mpdClient.addAlbumToQueue(album: album.mpdAlbum, at: queueLength)
   }
+
+  @IBAction func refreshAlbumArtMenuAction(_ sender: NSMenuItem) {
+    refreshAlbumArt()
+  }
 }

Persephone/Components/Browser/Album Browser/AlbumViewItem.xib

@@ -35,7 +35,7 @@
                                 </shadow>
                                 <buttonCell key="cell" type="square" bezelStyle="shadowlessSquare" image="defaultCoverArt" imagePosition="only" alignment="center" lineBreakMode="truncatingTail" refusesFirstResponder="YES" state="on" transparent="YES" imageScaling="proportionallyUpOrDown" inset="2" id="t8A-Hz-L38">
                                     <behavior key="behavior" pushIn="YES" lightByBackground="YES" lightByGray="YES"/>
-                                    <font key="font" metaFont="label" size="13"/>
+                                    <font key="font" metaFont="system"/>
                                 </buttonCell>
                                 <connections>
                                     <action selector="showAlbumDetail:" target="-2" id="A4Q-gb-B45"/>
@@ -54,7 +54,7 @@
                 <textField identifier="albumTitle" horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="KEh-NL-c2W">
                     <rect key="frame" x="8" y="28" width="142" height="17"/>
                     <textFieldCell key="cell" lineBreakMode="truncatingTail" title="Label" id="pDs-0t-e1j">
-                        <font key="font" metaFont="label" size="13"/>
+                        <font key="font" metaFont="system"/>
                         <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
                         <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
                     </textFieldCell>
@@ -62,7 +62,7 @@
                 <textField identifier="albumArtist" horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="5Uu-j1-qyT">
                     <rect key="frame" x="8" y="10" width="142" height="16"/>
                     <textFieldCell key="cell" lineBreakMode="truncatingTail" title="Label" id="yZn-e9-zyP">
-                        <font key="font" metaFont="label" size="13"/>
+                        <font key="font" metaFont="system"/>
                         <color key="textColor" name="secondaryLabelColor" catalog="System" colorSpace="catalog"/>
                         <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
                     </textFieldCell>
@@ -98,6 +98,13 @@
                         <action selector="addAlbumToQueueMenuAction:" target="-2" id="6wW-oR-ykh"/>
                     </connections>
                 </menuItem>
+                <menuItem isSeparatorItem="YES" id="g9v-9R-xDB"/>
+                <menuItem title="Refresh album art" id="4Ld-db-wka">
+                    <modifierMask key="keyEquivalentModifierMask"/>
+                    <connections>
+                        <action selector="refreshAlbumArtMenuAction:" target="-2" id="wyO-Dn-k9r"/>
+                    </connections>
+                </menuItem>
             </items>
             <point key="canvasLocation" x="191" y="38"/>
         </menu>

Persephone/Components/Browser/Album Detail/AlbumDetailView.swift

@@ -116,27 +116,27 @@ class AlbumDetailView: NSViewController {
     App.mpdClient.getAlbumSongs(for: album.mpdAlbum) { [weak self] (mpdSongs: [MPDClient.MPDSong]) in
       guard let self = self else { return }
 
-      self.dataSource.setAlbumSongs(
-        mpdSongs.map { Song(mpdSong: $0) }
-      )
-
       DispatchQueue.main.async {
+        self.dataSource.setAlbumSongs(
+          mpdSongs.map { Song(mpdSong: $0) }
+        )
+
         self.albumTracksView.reloadData()
+
+        guard let mpdSong = album.mpdAlbum.firstSong
+          else { return }
+
+        self.getBigCoverArt(song: Song(mpdSong: mpdSong), album: album)
       }
-
-      guard let song = self.dataSource.albumSongs.first?.song ??
-        self.dataSource.albumSongs[1].song
-        else { return }
-
-      self.getBigCoverArt(song: song, album: album)
     }
   }
 
   func getBigCoverArt(song: Song, album: Album) {
-    guard let imagePath = album.coverArtFilePath else { return }
+    let provider = MPDAlbumArtImageDataProvider(
+      songUri: song.mpdSong.uriString,
+      cacheKey: album.hash
+    )
 
-    let imageURL = URL(fileURLWithPath: imagePath)
-    let provider = LocalFileImageDataProvider(fileURL: imageURL)
     albumCoverView.kf.setImage(
       with: .provider(provider),
       placeholder: NSImage.defaultCoverArt,
@@ -145,18 +145,6 @@ class AlbumDetailView: NSViewController {
         .scaleFactor(2),
       ]
     )
-
-    cacheSmallCover(provider: provider)
-  }
-  
-  func cacheSmallCover(provider: ImageDataProvider) {
-    _ = KingfisherManager.shared.retrieveImage(
-      with: .provider(provider),
-      options: [
-        .processor(DownsamplingImageProcessor(size: .queueSongCoverSize)),
-        .scaleFactor(2),
-      ]
-    ) { result in }
   }
 
   func setAppearance() {

Persephone/Components/Browser/Album Detail/AlbumTracksDataSource.swift

@@ -50,7 +50,8 @@ class AlbumTracksDataSource: NSObject, NSTableViewDataSource {
         type: .albumSongItem(song.mpdSong.uriString),
         title: song.title,
         artist: song.artist,
-        cover: song.album.coverArtFilePath
+        album: song.album.title,
+        uri: song.mpdSong.uriString
       ),
       ofType: .songPasteboardType
     )
@@ -69,10 +70,11 @@ class AlbumTracksDataSource: NSObject, NSTableViewDataSource {
     ) { draggingItem, index, stop in
       guard let item = draggingItem.item as? NSPasteboardItem,
         let draggedSong = item.draggedSong(forType: .songPasteboardType),
-        case let (title?, artist?, cover?) = (
+        case let (title, artist, album, uri) = (
           draggedSong.title,
           draggedSong.artist,
-          draggedSong.cover
+          draggedSong.album,
+          draggedSong.uri
         )
         else { return }
 
@@ -81,7 +83,8 @@ class AlbumTracksDataSource: NSObject, NSTableViewDataSource {
         let draggedSongView = DraggedSongView(
           title: title,
           artist: artist,
-          cover: cover
+          album: album,
+          uri: uri
         )
 
         component.contents = draggedSongView.view.image()

Persephone/Components/Preferences/CoverArtPrefsController.swift

@@ -7,15 +7,12 @@
 //
 
 import AppKit
+import Kingfisher
 
 class CoverArtPrefsController: NSViewController {
   override func viewDidLoad() {
     super.viewDidLoad()
 
-    if let mpdLibraryDir = App.store.state.preferencesState.mpdLibraryDir {
-      mpdLibraryDirField.stringValue = mpdLibraryDir
-    }
-
     if App.store.state.preferencesState.fetchMissingArtworkFromInternet {
       fetchMissingArtworkFromInternet.state = .on
     } else {
@@ -33,12 +30,6 @@ class CoverArtPrefsController: NSViewController {
     self.parent?.view.window?.title = title
   }
 
-  @IBAction func updateMpdLibraryDir(_ sender: NSTextField) {
-    App.store.dispatch(UpdateMPDLibraryDir(mpdLibraryDir: sender.stringValue))
-  }
-
-  @IBOutlet var mpdLibraryDirField: NSTextField!
-
   @IBAction func updateFetchMissingArtworkFromInternet(_ sender: NSButton) {
     App.store.dispatch(
       UpdateFetchMissingArtworkFromInternet(
@@ -47,5 +38,10 @@ class CoverArtPrefsController: NSViewController {
     )
   }
 
+  @IBAction func clearAlbumArtCache(_ sender: NSButton) {
+    KingfisherManager.shared.cache.clearDiskCache()
+    KingfisherManager.shared.cache.clearMemoryCache()
+  }
+  
   @IBOutlet var fetchMissingArtworkFromInternet: NSButton!
 }

Persephone/Components/Queue/CurrentCoverArtView.swift

@@ -17,13 +17,23 @@ class CurrentCoverArtView: NSImageView {
     App.store.subscribe(self) {
       $0.select { $0.playerState.currentSong }
     }
+    
+    NotificationCenter.default.addObserver(self, selector: #selector(didReloadAlbumArt), name: .didReloadAlbumArt, object: nil)
+  }
+  
+  @objc func didReloadAlbumArt() {
+    guard let song = App.store.state.playerState.currentSong
+      else { return }
+    
+    setSongImage(song)
   }
 
-  func setAlbumImage(_ album: Album) {
-    guard let imagePath = album.coverArtFilePath else { return }
+  func setSongImage(_ song: Song) {
+    let provider = MPDAlbumArtImageDataProvider(
+      songUri: song.mpdSong.uriString,
+      cacheKey: song.album.hash
+    )
 
-    let imageURL = URL(fileURLWithPath: imagePath)
-    let provider = LocalFileImageDataProvider(fileURL: imageURL)
     kf.setImage(
       with: .provider(provider),
       placeholder: NSImage.defaultCoverArt,
@@ -44,6 +54,6 @@ extension CurrentCoverArtView: StoreSubscriber {
       return
     }
     
-    setAlbumImage(song.album)
+    setSongImage(song)
   }
 }

Persephone/Components/Queue/QueueDataSource.swift

@@ -44,7 +44,8 @@ class QueueDataSource: NSObject, NSOutlineViewDataSource {
         type: .queueItem(queueItem.queuePos),
         title: queueItem.song.title,
         artist: queueItem.song.artist,
-        cover: queueItem.song.album.coverArtFilePath
+        album: queueItem.song.album.title,
+        uri: queueItem.song.mpdSong.uriString
       ),
       ofType: .songPasteboardType
     )
@@ -128,10 +129,11 @@ class QueueDataSource: NSObject, NSOutlineViewDataSource {
       guard let item = draggingItem.item as? NSPasteboardItem,
         let data = item.data(forType: .songPasteboardType),
         let draggedSong = try? PropertyListDecoder().decode(DraggedSong.self, from: data),
-        case let (title?, artist?, cover?) = (
+        case let (title, artist, album, uri) = (
           draggedSong.title,
           draggedSong.artist,
-          draggedSong.cover
+          draggedSong.album,
+          draggedSong.uri
         )
         else { return }
 
@@ -140,7 +142,8 @@ class QueueDataSource: NSObject, NSOutlineViewDataSource {
         let draggedSongView = DraggedSongView(
           title: title,
           artist: artist,
-          cover: cover
+          album: album,
+          uri: uri
         )
 
         let view = draggedSongView.view

Persephone/Components/Queue/QueueSongCoverView.swift

@@ -60,14 +60,15 @@ class QueueSongCoverView: NSTableCellView {
   }
 
   func setSong(_ queueItem: QueueItem, queueIcon: NSImage?) {
-    guard let imagePath = queueItem.song.album.coverArtFilePath
-      else { return }
+    let song = queueItem.song
 
     isPlaying = queueItem.isPlaying
-
-    let imageURL = URL(fileURLWithPath: imagePath)
-    let provider = LocalFileImageDataProvider(fileURL: imageURL)
     
+    let provider = MPDAlbumArtImageDataProvider(
+      songUri: song.mpdSong.uriString,
+      cacheKey: song.album.hash
+    )
+
     queueSongCover.kf.setImage(
       with: .provider(provider),
       placeholder: NSImage.defaultCoverArt,

Persephone/Components/Queue/QueueViewController.swift

@@ -24,6 +24,7 @@ class QueueViewController: NSViewController {
 
     NotificationCenter.default.addObserver(self, selector: #selector(didConnect), name: .didConnect, object: nil)
     NotificationCenter.default.addObserver(self, selector: #selector(willDisconnect), name: .willDisconnect, object: nil)
+    NotificationCenter.default.addObserver(self, selector: #selector(didReloadAlbumArt), name: .didReloadAlbumArt, object: nil)
 
     queueView.dataSource = dataSource
     queueView.columnAutoresizingStyle = .sequentialColumnAutoresizingStyle
@@ -61,6 +62,10 @@ class QueueViewController: NSViewController {
       App.store.dispatch(UpdateQueueAction(queue: []))
     }
   }
+  
+  @objc func didReloadAlbumArt() {
+    queueView.reloadData()
+  }
 
   @IBAction func playTrack(_ sender: Any) {
     let queuePos = queueView.selectedRow

Persephone/Components/Shared/DraggedSongView.swift

@@ -16,12 +16,14 @@ class DraggedSongView: NSViewController {
   
   private let songTitle: String
   private let songArtist: String
-  private let songCover: String?
+  private let songAlbum: String
+  private let songUri: String
 
-  init(title: String, artist: String, cover: String? = nil) {
+  init(title: String, artist: String, album: String, uri: String) {
     songTitle = title
     songArtist = artist
-    songCover = cover
+    songAlbum = album
+    songUri = uri
 
     super.init(nibName: nil, bundle: nil)
   }
@@ -58,11 +60,13 @@ class DraggedSongView: NSViewController {
   }
   
   func setCoverArt() {
-    guard let imagePath = songCover else { return }
+    let mpdAlbum = MPDClient.MPDAlbum(title: songAlbum, artist: songArtist)
+
+    let provider = MPDAlbumArtImageDataProvider(
+      songUri: songUri,
+      cacheKey: Album(mpdAlbum: mpdAlbum).hash
+    )
 
-    let imageURL = URL(fileURLWithPath: imagePath)
-    let provider = LocalFileImageDataProvider(fileURL: imageURL)
-    
     coverImage.kf.setImage(
       with: .provider(provider),
       placeholder: NSImage.defaultCoverArt,

Persephone/Components/Shared/Extensions/NSImage.swift

@@ -15,34 +15,10 @@ extension NSImage {
   static let queuePauseIcon = NSImage(named: "queuePauseButton")
   
   static let defaultCoverArt = NSImage(named: "defaultCoverArt")
-
-  func toFitBox(size: NSSize) -> NSImage {
-    var newSize: NSSize = NSSize.zero
-    let aspectRatio = self.size.width / self.size.height
-    let boxAspectRatio = size.width / size.height
-
-    if aspectRatio > boxAspectRatio {
-      newSize = NSSize(width: size.width, height: size.width / aspectRatio)
-    } else {
-      newSize = NSSize(width: size.height * aspectRatio, height: size.height)
-    }
-
-    let newImage = NSImage(size: newSize)
-    newImage.lockFocus()
-    self.draw(in: newImage.alignmentRect)
-    newImage.unlockFocus()
-    return newImage
-  }
-
-  func jpegData(compressionQuality: CGFloat) -> Data? {
-    guard let image = cgImage(forProposedRect: nil, context: nil, hints: nil)
-      else { return nil }
-
-    let bitmapImageRep = NSBitmapImageRep(cgImage: image)
-
-    return bitmapImageRep.representation(
-      using: .jpeg,
-      properties: [.compressionFactor: compressionQuality]
-    )
-  }
+  
+  static let speakerDisabled = NSImage(named: "speakerDisabled")
+  static let speakerOff = NSImage(named: "speakerOff")
+  static let speakerLow = NSImage(named: "speakerLow")
+  static let speakerMid = NSImage(named: "speakerMid")
+  static let speakerHigh = NSImage(named: "speakerHigh")
 }

Persephone/Components/Shared/Extensions/Notification.swift

@@ -11,4 +11,5 @@ import Foundation
 extension Notification.Name {
   static let didConnect = Notification.Name("MPDClientDidConnect")
   static let willDisconnect = Notification.Name("MPDClientWillDisconnect")
+  static let didReloadAlbumArt = Notification.Name("MPDDidReloadAlbumArt")
 }

Persephone/Components/Shared/ImageDataProviders/MPDAlbumArtImageDataProvider.swift

@@ -0,0 +1,34 @@
+//
+//  MPDAlbumArtImageDataProvider.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2/1/20.
+//  Copyright © 2020 Dan Barber. All rights reserved.
+//
+
+import Foundation
+import Kingfisher
+
+public struct MPDAlbumArtImageDataProvider: ImageDataProvider {
+  let songUri: String
+
+  init(songUri: String, cacheKey: String) {
+    self.songUri = songUri
+    self.cacheKey = cacheKey
+  }
+
+  public var cacheKey: String
+
+  public func data(handler: @escaping (Result<Data, Error>) -> Void) {
+    App.mpdClient.fetchAlbumArt(songUri: songUri, imageData: nil) { imageData in
+      guard let imageData = imageData
+        else { return }
+
+      handler(.success(imageData))
+    }
+  }
+
+  public var contentURL: String? {
+    return songUri
+  }
+}

Persephone/Components/Shared/UserNotificationsController.swift

@@ -18,14 +18,16 @@ class UserNotificationsController {
   }
 
   func notifyTrack(_ state: Song?) {
-    guard let currentSong = state,
-      let coverArtFilePath = currentSong.album.coverArtFilePath,
+    guard let song = state,
       let status = App.mpdClient.status,
       status.state == .playing
       else { return }
+    
+    let provider = MPDAlbumArtImageDataProvider(
+      songUri: song.mpdSong.uriString,
+      cacheKey: song.album.hash
+    )
 
-    let imageURL = URL(fileURLWithPath: coverArtFilePath)
-    let provider = LocalFileImageDataProvider(fileURL: imageURL)
     _ = KingfisherManager.shared.retrieveImage(
       with: .provider(provider),
       options: [
@@ -35,7 +37,7 @@ class UserNotificationsController {
     ) { result in
       switch result {
       case .success(let value):
-        SongNotifierService(song: currentSong, image: value.image)
+        SongNotifierService(song: song, image: value.image)
           .deliver()
       case .failure:
         break

Persephone/Components/VolumeControl/VolumeControlView.swift

@@ -0,0 +1,45 @@
+  //
+//  VolumeControlView.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2/16/20.
+//  Copyright © 2020 Dan Barber. All rights reserved.
+//
+
+import AppKit
+import ReSwift
+
+class VolumeControlView: NSViewController {
+  static let shared = VolumeControlView()
+  static let popover = NSPopover()
+  
+  var currentVolume: Int = 0
+
+  override func viewDidLoad() {
+    super.viewDidLoad()
+    
+    App.store.subscribe(self) {
+      $0.select { $0.playerState }
+    }
+  }
+  
+  @IBAction func volumeSliderAction(_ sender: NSSlider) {
+    let newVolume = sender.integerValue
+
+    if newVolume != currentVolume {
+      App.mpdClient.setVolume(to: newVolume)
+      currentVolume = newVolume
+    }
+  }
+  
+  @IBOutlet var volumeSlider: NSSlider!
+}
+  
+extension VolumeControlView: StoreSubscriber {
+  typealias StoreSubscriberStateType = PlayerState
+  
+  func newState(state: StoreSubscriberStateType) {
+    volumeSlider.integerValue = state.volume
+    currentVolume = state.volume
+  }
+}

Persephone/Components/VolumeControl/VolumeControlView.xib

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="15705" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
+    <dependencies>
+        <deployment identifier="macosx"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="15705"/>
+        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
+    </dependencies>
+    <objects>
+        <customObject id="-2" userLabel="File's Owner" customClass="VolumeControlView" customModule="Persephone" customModuleProvider="target">
+            <connections>
+                <outlet property="view" destination="Hz6-mo-xeY" id="0bl-1N-x8E"/>
+                <outlet property="volumeSlider" destination="E78-vZ-qV0" id="7qP-Fm-MDY"/>
+            </connections>
+        </customObject>
+        <customObject id="-1" userLabel="First Responder" customClass="FirstResponder"/>
+        <customObject id="-3" userLabel="Application" customClass="NSObject"/>
+        <customView id="Hz6-mo-xeY">
+            <rect key="frame" x="0.0" y="0.0" width="36" height="145"/>
+            <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
+            <subviews>
+                <slider horizontalHuggingPriority="750" fixedFrame="YES" translatesAutoresizingMaskIntoConstraints="NO" id="E78-vZ-qV0" userLabel="Volume Slider">
+                    <rect key="frame" x="9" y="12" width="19" height="121"/>
+                    <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
+                    <sliderCell key="cell" continuous="YES" alignment="left" maxValue="100" doubleValue="50" tickMarkPosition="right" sliderType="linear" id="22u-9w-IXT"/>
+                    <connections>
+                        <action selector="volumeSliderAction:" target="-2" id="1yh-vH-sgN"/>
+                    </connections>
+                </slider>
+            </subviews>
+            <point key="canvasLocation" x="-83" y="90.5"/>
+        </customView>
+    </objects>
+</document>

Persephone/Components/Window/Base.lproj/Main.storyboard

@@ -208,7 +208,7 @@
                                         <rect key="frame" x="0.0" y="14" width="153" height="24"/>
                                         <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
                                         <segmentedCell key="cell" borderStyle="border" alignment="left" style="texturedRounded" trackingMode="momentary" id="EBk-sD-nG7">
-                                            <font key="font" metaFont="system"/>
+                                            <font key="font" metaFont="label" size="13"/>
                                             <segments>
                                                 <segment image="prevTrackButton" width="32" enabled="NO"/>
                                                 <segment image="playButton" width="48" enabled="NO" tag="1"/>
@@ -230,7 +230,7 @@
                                         <rect key="frame" x="16" y="14" width="55" height="17"/>
                                         <autoresizingMask key="autoresizingMask"/>
                                         <textFieldCell key="cell" lineBreakMode="clipping" alignment="right" placeholderString="8:88:88" id="g0c-k5-wCA">
-                                            <font key="font" metaFont="system"/>
+                                            <font key="font" metaFont="label" size="13"/>
                                             <color key="textColor" name="tertiaryLabelColor" catalog="System" colorSpace="catalog"/>
                                             <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
                                         </textFieldCell>
@@ -257,7 +257,7 @@
                                         <rect key="frame" x="16" y="14" width="60" height="17"/>
                                         <autoresizingMask key="autoresizingMask"/>
                                         <textFieldCell key="cell" lineBreakMode="clipping" alignment="left" placeholderString="-8:88:88" id="XUa-pD-s5c">
-                                            <font key="font" metaFont="system"/>
+                                            <font key="font" metaFont="label" size="13"/>
                                             <color key="textColor" name="tertiaryLabelColor" catalog="System" colorSpace="catalog"/>
                                             <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
                                         </textFieldCell>
@@ -277,9 +277,9 @@
                                     <button key="view" verticalHuggingPriority="750" id="E8L-uK-XT0">
                                         <rect key="frame" x="2" y="14" width="42" height="24"/>
                                         <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
-                                        <buttonCell key="cell" type="roundTextured" bezelStyle="texturedRounded" image="shuffleButton" imagePosition="only" alignment="center" lineBreakMode="truncatingTail" borderStyle="border" inset="2" id="YNb-hd-ax8">
+                                        <buttonCell key="cell" type="roundTextured" bezelStyle="texturedRounded" image="shuffleButton" imagePosition="overlaps" alignment="center" lineBreakMode="truncatingTail" borderStyle="border" inset="2" id="YNb-hd-ax8">
                                             <behavior key="behavior" pushIn="YES" changeContents="YES" lightByContents="YES"/>
-                                            <font key="font" metaFont="system"/>
+                                            <font key="font" metaFont="label" size="13"/>
                                         </buttonCell>
                                         <connections>
                                             <action selector="handleShuffleButton:" target="B8D-0N-5wS" id="THd-0g-fmb"/>
@@ -295,7 +295,7 @@
                                         <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
                                         <buttonCell key="cell" type="roundTextured" bezelStyle="texturedRounded" image="repeatButton" imagePosition="only" alignment="center" lineBreakMode="truncatingTail" borderStyle="border" inset="2" id="1bu-vK-3Hb">
                                             <behavior key="behavior" pushIn="YES" changeContents="YES" lightByContents="YES"/>
-                                            <font key="font" metaFont="system"/>
+                                            <font key="font" metaFont="label" size="13"/>
                                         </buttonCell>
                                         <connections>
                                             <action selector="handleRepeatButton:" target="B8D-0N-5wS" id="EN2-u4-DNl"/>
@@ -308,7 +308,7 @@
                                         <rect key="frame" x="0.0" y="14" width="96" height="22"/>
                                         <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
                                         <searchFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" selectable="YES" editable="YES" borderStyle="bezel" usesSingleLineMode="YES" bezelStyle="round" id="F3N-3P-tS3">
-                                            <font key="font" metaFont="system"/>
+                                            <font key="font" metaFont="label" size="13"/>
                                             <color key="textColor" name="controlTextColor" catalog="System" colorSpace="catalog"/>
                                             <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
                                         </searchFieldCell>
@@ -317,6 +317,20 @@
                                         </connections>
                                     </searchField>
                                 </toolbarItem>
+                                <toolbarItem implicitItemIdentifier="01E8DA80-2BDE-49F9-B311-69876CF0AE8E" label="Volume" paletteLabel="Volume" image="speakerHigh" sizingBehavior="auto" id="cMg-Mj-j7q">
+                                    <nil key="toolTip"/>
+                                    <button key="view" verticalHuggingPriority="750" id="cfN-LI-Cab">
+                                        <rect key="frame" x="2" y="14" width="42" height="24"/>
+                                        <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
+                                        <buttonCell key="cell" type="roundTextured" bezelStyle="texturedRounded" image="speakerHigh" imagePosition="overlaps" alignment="center" borderStyle="border" imageScaling="proportionallyDown" inset="2" id="bJh-X9-7q0">
+                                            <behavior key="behavior" pushIn="YES" lightByBackground="YES" lightByGray="YES"/>
+                                            <font key="font" metaFont="label" size="13"/>
+                                        </buttonCell>
+                                        <connections>
+                                            <action selector="showVolumeControl:" target="B8D-0N-5wS" id="UoW-fa-jBM"/>
+                                        </connections>
+                                    </button>
+                                </toolbarItem>
                             </allowedToolbarItems>
                             <defaultToolbarItems>
                                 <toolbarItem reference="p3r-ty-Pxf"/>
@@ -329,6 +343,8 @@
                                 <toolbarItem reference="s1h-EC-nvL"/>
                                 <toolbarItem reference="5U7-UV-xn2"/>
                                 <toolbarItem reference="9ol-aR-mzv"/>
+                                <toolbarItem reference="cMg-Mj-j7q"/>
+                                <toolbarItem reference="mhg-16-CNM"/>
                                 <toolbarItem reference="FRe-rR-Ulo"/>
                             </defaultToolbarItems>
                         </toolbar>
@@ -345,6 +361,7 @@
                         <outlet property="trackProgressBar" destination="KMy-xf-rmN" id="a67-JU-cyQ"/>
                         <outlet property="trackRemaining" destination="9WZ-ij-lrb" id="0pH-d7-wvD"/>
                         <outlet property="transportControls" destination="EBk-sD-nG7" id="yOo-58-Fby"/>
+                        <outlet property="volumeState" destination="cfN-LI-Cab" id="hrE-SY-J9E"/>
                         <segue destination="fnD-7K-pHK" kind="relationship" relationship="window.shadowedContentViewController" id="fQQ-kB-KVc"/>
                     </connections>
                 </windowController>
@@ -409,7 +426,7 @@
                     <tabView key="tabView" type="noTabsNoBorder" id="6dC-M0-oC5">
                         <rect key="frame" x="0.0" y="0.0" width="418" height="300"/>
                         <autoresizingMask key="autoresizingMask"/>
-                        <font key="font" metaFont="system"/>
+                        <font key="font" metaFont="label" size="13"/>
                         <connections>
                             <outlet property="delegate" destination="zhe-qh-Mal" id="LUL-qN-JlP"/>
                         </connections>
@@ -429,93 +446,47 @@
             <objects>
                 <viewController title="Cover Art" id="3C9-vU-zjZ" userLabel="Cover Art" customClass="CoverArtPrefsController" customModule="Persephone" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" id="PyK-v2-kus">
-                        <rect key="frame" x="0.0" y="0.0" width="524" height="168"/>
+                        <rect key="frame" x="0.0" y="0.0" width="420" height="103"/>
                         <autoresizingMask key="autoresizingMask"/>
                         <subviews>
-                            <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="zZn-Rm-e1f">
-                                <rect key="frame" x="53" y="129" width="104" height="16"/>
-                                <textFieldCell key="cell" lineBreakMode="clipping" title="Music Directory:" id="sPn-V6-CfK">
-                                    <font key="font" usesAppearanceFont="YES"/>
-                                    <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
-                                    <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
-                                </textFieldCell>
-                            </textField>
-                            <textField verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="gDk-ca-eOa">
-                                <rect key="frame" x="162" y="125" width="288" height="21"/>
-                                <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" selectable="YES" editable="YES" sendsActionOnEndEditing="YES" borderStyle="bezel" placeholderString="~/Music" drawsBackground="YES" id="7WZ-b7-GUs">
-                                    <font key="font" metaFont="system"/>
-                                    <color key="textColor" name="controlTextColor" catalog="System" colorSpace="catalog"/>
-                                    <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
-                                </textFieldCell>
-                                <connections>
-                                    <action selector="updateMpdLibraryDir:" target="3C9-vU-zjZ" id="3Ta-fH-5Zh"/>
-                                </connections>
-                            </textField>
                             <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="pRL-MG-1Be">
-                                <rect key="frame" x="160" y="94" width="264" height="18"/>
+                                <rect key="frame" x="82" y="67" width="264" height="18"/>
+                                <constraints>
+                                    <constraint firstAttribute="width" constant="260" id="PJN-iZ-3RV"/>
+                                </constraints>
                                 <buttonCell key="cell" type="check" title="Fetch missing artwork from MusicBrainz" bezelStyle="regularSquare" imagePosition="left" enabled="NO" inset="2" id="LpD-Ew-HMd">
                                     <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
-                                    <font key="font" metaFont="system"/>
+                                    <font key="font" metaFont="label" size="13"/>
                                 </buttonCell>
                                 <connections>
                                     <action selector="updateFetchMissingArtworkFromInternet:" target="3C9-vU-zjZ" id="I7x-9V-xJr"/>
                                 </connections>
                             </button>
-                            <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="z1g-nP-ksw">
-                                <rect key="frame" x="160" y="63" width="264" height="18"/>
-                                <constraints>
-                                    <constraint firstAttribute="width" constant="260" id="gK0-aW-CJy"/>
-                                </constraints>
-                                <buttonCell key="cell" type="check" title="Save fetched artwork to music directory" bezelStyle="regularSquare" imagePosition="left" enabled="NO" inset="2" id="ZeZ-O4-vjS">
-                                    <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
-                                    <font key="font" metaFont="system"/>
+                            <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="mXh-kY-tMC">
+                                <rect key="frame" x="78" y="21" width="185" height="32"/>
+                                <buttonCell key="cell" type="push" title="Clear album art cache..." bezelStyle="rounded" alignment="center" borderStyle="border" imageScaling="proportionallyDown" inset="2" id="l81-SG-7mf">
+                                    <behavior key="behavior" pushIn="YES" lightByBackground="YES" lightByGray="YES"/>
+                                    <font key="font" metaFont="label" size="13"/>
                                 </buttonCell>
+                                <connections>
+                                    <action selector="clearAlbumArtCache:" target="3C9-vU-zjZ" id="tXg-rz-lvh"/>
+                                </connections>
                             </button>
-                            <textField verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="xgS-Kg-8KR">
-                                <rect key="frame" x="162" y="26" width="144" height="21"/>
-                                <constraints>
-                                    <constraint firstAttribute="width" constant="144" id="DSX-th-Wn1"/>
-                                </constraints>
-                                <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" selectable="YES" editable="YES" enabled="NO" sendsActionOnEndEditing="YES" borderStyle="bezel" placeholderString="folder.jpg" drawsBackground="YES" id="nKF-YI-xBL">
-                                    <font key="font" metaFont="system"/>
-                                    <color key="textColor" name="controlTextColor" catalog="System" colorSpace="catalog"/>
-                                    <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
-                                </textFieldCell>
-                            </textField>
-                            <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="SmH-w6-5QI">
-                                <rect key="frame" x="37" y="30" width="119" height="16"/>
-                                <textFieldCell key="cell" lineBreakMode="clipping" enabled="NO" alignment="right" title="Cover art filename:" id="b4u-u7-iWD">
-                                    <font key="font" metaFont="system"/>
-                                    <color key="textColor" name="secondaryLabelColor" catalog="System" colorSpace="catalog"/>
-                                    <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
-                                </textFieldCell>
-                            </textField>
                         </subviews>
                         <constraints>
-                            <constraint firstItem="pRL-MG-1Be" firstAttribute="centerX" secondItem="z1g-nP-ksw" secondAttribute="centerX" id="0Ev-Ia-XBO"/>
-                            <constraint firstItem="gDk-ca-eOa" firstAttribute="leading" secondItem="pRL-MG-1Be" secondAttribute="leading" id="1jd-wZ-a4Q"/>
-                            <constraint firstItem="pRL-MG-1Be" firstAttribute="leading" secondItem="z1g-nP-ksw" secondAttribute="leading" id="3tZ-Ub-RaT"/>
-                            <constraint firstItem="gDk-ca-eOa" firstAttribute="leading" secondItem="zZn-Rm-e1f" secondAttribute="trailing" constant="7" id="C0m-yx-gXh"/>
-                            <constraint firstItem="z1g-nP-ksw" firstAttribute="leading" secondItem="xgS-Kg-8KR" secondAttribute="leading" id="Dkv-ai-X2G"/>
-                            <constraint firstItem="xgS-Kg-8KR" firstAttribute="leading" secondItem="SmH-w6-5QI" secondAttribute="trailing" constant="8" symbolic="YES" id="KQk-nr-H8y"/>
-                            <constraint firstItem="zZn-Rm-e1f" firstAttribute="leading" secondItem="PyK-v2-kus" secondAttribute="leading" constant="55" id="OzK-MR-zuB"/>
-                            <constraint firstAttribute="bottom" secondItem="SmH-w6-5QI" secondAttribute="bottom" constant="30" id="aBY-Ny-jPe"/>
-                            <constraint firstItem="pRL-MG-1Be" firstAttribute="top" secondItem="gDk-ca-eOa" secondAttribute="bottom" constant="15" id="dKy-uC-r43"/>
-                            <constraint firstItem="xgS-Kg-8KR" firstAttribute="top" secondItem="z1g-nP-ksw" secondAttribute="bottom" constant="18" id="lfR-Im-bd4"/>
-                            <constraint firstAttribute="trailing" secondItem="gDk-ca-eOa" secondAttribute="trailing" constant="74" id="n8X-T2-tXA"/>
-                            <constraint firstAttribute="bottom" secondItem="xgS-Kg-8KR" secondAttribute="bottom" constant="26" id="oXZ-qo-HwX"/>
-                            <constraint firstItem="SmH-w6-5QI" firstAttribute="top" secondItem="zZn-Rm-e1f" secondAttribute="bottom" constant="83" id="qhC-mD-Bvw"/>
-                            <constraint firstItem="z1g-nP-ksw" firstAttribute="top" secondItem="pRL-MG-1Be" secondAttribute="bottom" constant="17" id="sTP-hk-zfU"/>
+                            <constraint firstItem="pRL-MG-1Be" firstAttribute="leading" secondItem="PyK-v2-kus" secondAttribute="leading" constant="84" id="81s-YL-o8A"/>
+                            <constraint firstAttribute="bottom" secondItem="pRL-MG-1Be" secondAttribute="bottom" constant="69" id="L7b-jE-keG"/>
+                            <constraint firstItem="mXh-kY-tMC" firstAttribute="leading" secondItem="pRL-MG-1Be" secondAttribute="leading" id="b9X-hO-aYJ"/>
+                            <constraint firstAttribute="bottom" secondItem="mXh-kY-tMC" secondAttribute="bottom" constant="28" id="ras-nE-Oq8"/>
                         </constraints>
                     </view>
                     <connections>
                         <outlet property="fetchMissingArtworkFromInternet" destination="pRL-MG-1Be" id="Xcp-sb-iZm"/>
-                        <outlet property="mpdLibraryDirField" destination="gDk-ca-eOa" id="myi-BQ-0NS"/>
                     </connections>
                 </viewController>
                 <customObject id="KzD-E3-lpA" userLabel="First Responder" customClass="NSResponder" sceneMemberID="firstResponder"/>
             </objects>
-            <point key="canvasLocation" x="1459" y="-242"/>
+            <point key="canvasLocation" x="1407" y="-274.5"/>
         </scene>
         <!--View Controller-->
         <scene sceneID="VvW-vT-alQ">
@@ -528,7 +499,7 @@
                         <subviews>
                             <tabView type="noTabsNoBorder" initialItem="XgS-cX-SDH" translatesAutoresizingMaskIntoConstraints="NO" id="ARv-cj-xlz">
                                 <rect key="frame" x="0.0" y="0.0" width="478" height="558"/>
-                                <font key="font" metaFont="system"/>
+                                <font key="font" metaFont="label" size="13"/>
                                 <tabViewItems>
                                     <tabViewItem label="Albums" identifier="" id="XgS-cX-SDH">
                                         <view key="view" id="hB7-hN-SbB">
@@ -593,7 +564,7 @@
                                         <real key="minimum" value="0.0"/>
                                         <real key="maximum" value="65535"/>
                                     </numberFormatter>
-                                    <font key="font" metaFont="system"/>
+                                    <font key="font" metaFont="label" size="13"/>
                                     <color key="textColor" name="controlTextColor" catalog="System" colorSpace="catalog"/>
                                     <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
                                 </textFieldCell>
@@ -604,7 +575,7 @@
                             <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="kvB-99-zwY">
                                 <rect key="frame" x="76" y="61" width="80" height="16"/>
                                 <textFieldCell key="cell" lineBreakMode="clipping" alignment="right" title="Server Host:" id="AVi-g9-Irz">
-                                    <font key="font" metaFont="system"/>
+                                    <font key="font" metaFont="label" size="13"/>
                                     <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
                                     <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
                                 </textFieldCell>
@@ -615,7 +586,7 @@
                                     <constraint firstAttribute="width" constant="72" id="Of6-Ls-knP"/>
                                 </constraints>
                                 <textFieldCell key="cell" lineBreakMode="clipping" alignment="right" title="Server Port:" id="DgA-xT-2ir">
-                                    <font key="font" metaFont="system"/>
+                                    <font key="font" metaFont="label" size="13"/>
                                     <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
                                     <color key="backgroundColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
                                 </textFieldCell>
@@ -647,18 +618,18 @@
             <objects>
                 <viewController id="KIP-rq-4dM" customClass="QueueViewController" customModule="Persephone" customModuleProvider="target" sceneMemberID="viewController">
                     <splitView key="view" misplaced="YES" dividerStyle="thin" id="84I-w3-Mxl">
-                        <rect key="frame" x="0.0" y="0.0" width="329" height="543"/>
+                        <rect key="frame" x="0.0" y="0.0" width="329" height="498"/>
                         <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
                         <subviews>
                             <scrollView borderType="none" autohidesScrollers="YES" horizontalLineScroll="42" horizontalPageScroll="10" verticalLineScroll="42" verticalPageScroll="10" usesPredominantAxisScrolling="NO" id="S3o-nF-NN7">
-                                <rect key="frame" x="0.0" y="0.0" width="329" height="217"/>
+                                <rect key="frame" x="0.0" y="0.0" width="329" height="198"/>
                                 <autoresizingMask key="autoresizingMask" flexibleMaxY="YES"/>
                                 <clipView key="contentView" drawsBackground="NO" id="WI8-Pw-03L">
-                                    <rect key="frame" x="0.0" y="0.0" width="329" height="217"/>
+                                    <rect key="frame" x="0.0" y="0.0" width="329" height="198"/>
                                     <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                     <subviews>
                                         <outlineView verticalHuggingPriority="750" allowsExpansionToolTips="YES" columnAutoresizingStyle="lastColumnOnly" selectionHighlightStyle="sourceList" multipleSelection="NO" autosaveColumns="NO" rowHeight="42" rowSizeStyle="automatic" viewBased="YES" indentationMarkerFollowsCell="NO" outlineTableColumn="0Co-uF-CCB" id="jEJ-jg-fll">
-                                            <rect key="frame" x="0.0" y="0.0" width="329" height="217"/>
+                                            <rect key="frame" x="0.0" y="0.0" width="329" height="198"/>
                                             <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                             <size key="intercellSpacing" width="3" height="0.0"/>
                                             <color key="backgroundColor" name="_sourceListBackgroundColor" catalog="System" colorSpace="catalog"/>
@@ -666,12 +637,11 @@
                                             <tableColumns>
                                                 <tableColumn identifier="songCoverColumn" width="43" minWidth="42" maxWidth="1000" id="0Co-uF-CCB" userLabel="Position">
                                                     <tableHeaderCell key="headerCell" lineBreakMode="truncatingTail" borderStyle="border">
-                                                        <font key="font" metaFont="message" size="11"/>
                                                         <color key="textColor" name="headerTextColor" catalog="System" colorSpace="catalog"/>
                                                         <color key="backgroundColor" name="headerColor" catalog="System" colorSpace="catalog"/>
                                                     </tableHeaderCell>
                                                     <textFieldCell key="dataCell" lineBreakMode="truncatingTail" selectable="YES" editable="YES" title="Text Cell" id="99v-Rb-3kv">
-                                                        <font key="font" metaFont="system"/>
+                                                        <font key="font" metaFont="label" size="13"/>
                                                         <color key="textColor" name="controlTextColor" catalog="System" colorSpace="catalog"/>
                                                         <color key="backgroundColor" name="controlBackgroundColor" catalog="System" colorSpace="catalog"/>
                                                     </textFieldCell>
@@ -712,12 +682,11 @@
                                                 </tableColumn>
                                                 <tableColumn identifier="songInfoColumn" width="213" minWidth="10" maxWidth="3.4028234663852886e+38" id="HP0-ty-PFY" userLabel="Song Info">
                                                     <tableHeaderCell key="headerCell" lineBreakMode="truncatingTail" borderStyle="border" alignment="left">
-                                                        <font key="font" metaFont="message" size="11"/>
                                                         <color key="textColor" name="headerTextColor" catalog="System" colorSpace="catalog"/>
                                                         <color key="backgroundColor" white="0.0" alpha="0.0" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                                                     </tableHeaderCell>
                                                     <textFieldCell key="dataCell" lineBreakMode="truncatingTail" selectable="YES" editable="YES" alignment="left" title="Text Cell" id="zb2-QK-DhK">
-                                                        <font key="font" metaFont="system"/>
+                                                        <font key="font" metaFont="label" size="13"/>
                                                         <color key="textColor" name="controlTextColor" catalog="System" colorSpace="catalog"/>
                                                         <color key="backgroundColor" name="controlBackgroundColor" catalog="System" colorSpace="catalog"/>
                                                     </textFieldCell>
@@ -738,7 +707,7 @@
                                                                 <textField verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="i0h-bn-auJ" userLabel="Song Title View">
                                                                     <rect key="frame" x="1" y="23" width="211" height="16"/>
                                                                     <textFieldCell key="cell" lineBreakMode="truncatingTail" sendsActionOnEndEditing="YES" title="Song Title" id="ei8-1e-ErK">
-                                                                        <font key="font" metaFont="system"/>
+                                                                        <font key="font" metaFont="label" size="13"/>
                                                                         <color key="textColor" name="controlTextColor" catalog="System" colorSpace="catalog"/>
                                                                         <color key="backgroundColor" name="controlColor" catalog="System" colorSpace="catalog"/>
                                                                     </textFieldCell>
@@ -761,12 +730,11 @@
                                                 </tableColumn>
                                                 <tableColumn identifier="songDurationColumn" width="64" minWidth="64" maxWidth="64" id="8O6-ox-kx2" userLabel="Duration">
                                                     <tableHeaderCell key="headerCell" lineBreakMode="truncatingTail" borderStyle="border" alignment="left">
-                                                        <font key="font" metaFont="message" size="11"/>
                                                         <color key="textColor" name="headerTextColor" catalog="System" colorSpace="catalog"/>
                                                         <color key="backgroundColor" white="0.0" alpha="0.0" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                                                     </tableHeaderCell>
                                                     <textFieldCell key="dataCell" lineBreakMode="truncatingTail" selectable="YES" editable="YES" alignment="left" title="Text Cell" id="JOa-Mc-ceQ">
-                                                        <font key="font" metaFont="system"/>
+                                                        <font key="font" metaFont="label" size="13"/>
                                                         <color key="textColor" name="controlTextColor" catalog="System" colorSpace="catalog"/>
                                                         <color key="backgroundColor" name="controlBackgroundColor" catalog="System" colorSpace="catalog"/>
                                                     </textFieldCell>
@@ -783,7 +751,7 @@
                                                                         <constraint firstAttribute="height" constant="17" id="grB-CG-1vJ"/>
                                                                     </constraints>
                                                                     <textFieldCell key="cell" lineBreakMode="truncatingTail" sendsActionOnEndEditing="YES" alignment="right" title="88:88" id="JnJ-sF-vCP">
-                                                                        <font key="font" metaFont="system"/>
+                                                                        <font key="font" metaFont="label" size="13"/>
                                                                         <color key="textColor" name="secondaryLabelColor" catalog="System" colorSpace="catalog"/>
                                                                         <color key="backgroundColor" name="controlColor" catalog="System" colorSpace="catalog"/>
                                                                     </textFieldCell>
@@ -824,7 +792,7 @@
                                 </scroller>
                             </scrollView>
                             <customView misplaced="YES" id="iUb-eV-Qws">
-                                <rect key="frame" x="0.0" y="218" width="329" height="325"/>
+                                <rect key="frame" x="0.0" y="199" width="329" height="299"/>
                                 <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
                                 <subviews>
                                     <imageView horizontalHuggingPriority="251" verticalHuggingPriority="251" horizontalCompressionResistancePriority="250" verticalCompressionResistancePriority="250" translatesAutoresizingMaskIntoConstraints="NO" id="Dw3-M5-tWY" customClass="CurrentCoverArtView" customModule="Persephone" customModuleProvider="target">
@@ -932,6 +900,7 @@
         <image name="prevTrackButton" width="17" height="17"/>
         <image name="repeatButton" width="17" height="17"/>
         <image name="shuffleButton" width="17" height="17"/>
+        <image name="speakerHigh" width="21" height="17"/>
         <image name="stopButton" width="17" height="17"/>
     </resources>
 </document>

Persephone/Components/Window/WindowController.swift

@@ -27,6 +27,8 @@ class WindowController: NSWindowController {
   @IBOutlet var shuffleState: NSButton!
   @IBOutlet var repeatState: NSButton!
 
+  @IBOutlet var volumeState: NSButton!
+
   @IBOutlet weak var searchQuery: NSSearchField!
 
   override func windowDidLoad() {
@@ -120,6 +122,25 @@ class WindowController: NSWindowController {
 
     trackRemaining.stringValue = time.formattedTime
   }
+  
+  func setVolumeControlIcon(_ state: PlayerState) {
+    volumeState.isEnabled = state.volume != -1
+
+    switch state.volume {
+    case -1:
+      volumeState.image = .speakerDisabled
+    case 0..<5:
+      volumeState.image = .speakerOff
+    case 5..<40:
+      volumeState.image = .speakerLow
+    case 40..<70:
+      volumeState.image = .speakerMid
+    case 70...100:
+      volumeState.image = .speakerHigh
+    default:
+      break
+    }
+  }
     
   @objc func willDisconnect() {
     DispatchQueue.main.async {
@@ -176,6 +197,16 @@ class WindowController: NSWindowController {
   @IBAction func handleSearchQuery(_ sender: NSSearchField) {
     App.store.dispatch(SetSearchQuery(searchQuery: sender.stringValue))
   }
+  
+  @IBAction func showVolumeControl(_ sender: NSButton) {
+    VolumeControlView.popover.contentViewController = VolumeControlView.shared
+    VolumeControlView.popover.behavior = .transient
+    VolumeControlView.popover.show(
+      relativeTo: sender.bounds,
+      of: sender,
+      preferredEdge: .maxY
+    )
+  }
 }
 
 extension WindowController: NSWindowDelegate {
@@ -201,6 +232,7 @@ extension WindowController: StoreSubscriber {
       self.setShuffleRepeatState(state.playerState)
       self.setTrackProgressControls(state.playerState)
       self.setDatabaseUpdatingIndicator(state.uiState)
+      self.setVolumeControlIcon(state.playerState)
     }
   }
 }

Persephone/MPDClient/Extensions/MPDClient+Album.swift

@@ -74,8 +74,8 @@ extension MPDClient {
       let mpdAlbum = MPDAlbum(
         title: mpdSong.album.title,
         artist: mpdSong.artist,
-        date: mpdSong.date,
-        path: mpdSong.path
+        firstSong: mpdSong,
+        date: mpdSong.date
       )
       if (mpdAlbum != albums.last) {
         albums.append(mpdAlbum)

Persephone/MPDClient/Extensions/MPDClient+Command.swift

@@ -46,6 +46,11 @@ extension MPDClient {
       guard let repeatState = userData["repeatState"] as? Bool
         else { return }
       sendRepeatState(repeatState: repeatState)
+      
+    case .setVolume:
+      guard let volume = userData["volume"] as? Int
+        else { return }
+      sendSetVolume(to: volume)
 
     // Database commands
     case .updateDatabase:
@@ -119,6 +124,22 @@ extension MPDClient {
         else { return }
 
       albumSongs(for: album, callback: callback)
+      
+      // Song commands
+      case .fetchAlbumArt:
+        guard let songUri = userData["songUri"] as? String,
+          let offset = userData["offset"] as? Int32,
+          let callback = userData["callback"] as? (Data?) -> Void
+          else { return }
+      
+        let imageData = userData["imageData"] as? Data? ?? nil
+        
+        sendFetchAlbumArt(
+          forUri: songUri,
+          imageData: imageData,
+          offset: offset,
+          callback: callback
+        )
     }
     
   }
@@ -126,6 +147,7 @@ extension MPDClient {
   func enqueueCommand(
     command: MPDCommand,
     priority: BlockOperation.QueuePriority = .normal,
+    forceIdle: Bool = false,
     userData: Dictionary<String, Any> = [:]
   ) {
     guard isConnected else { return }
@@ -135,8 +157,9 @@ extension MPDClient {
     let commandOperation = BlockOperation() { [unowned self] in
       self.sendCommand(command: command, userData: userData)
 
-      self.idle()
+      self.idle(forceIdle)
     }
+
     commandOperation.queuePriority = priority
     commandQueue.addOperation(commandOperation)
   }

Persephone/MPDClient/Extensions/MPDClient+Idle.swift

@@ -11,58 +11,81 @@ import mpdclient
 
 extension MPDClient {
   func noIdle() {
-    if isIdle {
-      mpd_send_noidle(connection)
-      isIdle = false
+    do {
+      idleLock.lock()
+      defer { idleLock.unlock() }
+      if isIdle {
+        mpd_send_noidle(connection)
+        isIdle = false
+      }
     }
   }
 
-  func idle() {
-    if !self.isIdle && self.commandQueue.operationCount == 1 {
-      mpd_send_idle(self.connection)
-      self.isIdle = true
+  func idle(_ force: Bool = false) {
+    let shouldIdle: Bool
+  
+    do {
+      idleLock.lock()
+      defer { idleLock.unlock() }
+      shouldIdle = (!isIdle && commandQueue.operationCount == 1) || force
+      if shouldIdle {
+        mpd_send_idle(connection)
+        self.isIdle = true
+      }
+    }
 
-      let result = mpd_recv_idle(self.connection, true)
-      self.handleIdleResult(result)
+    if shouldIdle {
+      let result = mpd_recv_idle(connection, true)
+      handleIdleResult(result)
     }
   }
 
   func handleIdleResult(_ result: mpd_idle) {
-    isIdle = false
-    
     let mpdIdle = MPDIdle(rawValue: result.rawValue)
+    let wasIdle: Bool
 
-    if mpdIdle.contains(.database) {
-      self.fetchAllAlbums()
+    do {
+      idleLock.lock()
+      defer { idleLock.unlock() }
+      wasIdle = isIdle
+      isIdle = false
     }
-    if mpdIdle.contains(.queue) {
-      self.fetchQueue()
-      self.fetchStatus()
 
-      self.delegate?.didUpdateQueue(mpdClient: self, queue: self.queue)
-      if let status = self.status {
-        self.delegate?.didUpdateQueuePos(mpdClient: self, song: status.song)
+    if wasIdle {
+      if mpdIdle.contains(.database) {
+        self.fetchAllAlbums()
       }
-    }
-    if mpdIdle.contains(.player) || mpdIdle.contains(.options) {
-      self.fetchStatus()
+      if mpdIdle.contains(.queue) {
+        self.fetchQueue()
+        self.fetchStatus()
 
-      if let status = self.status {
-        self.delegate?.didUpdateStatus(mpdClient: self, status: status)
-        self.delegate?.didUpdateQueuePos(mpdClient: self, song: status.song)
+        self.delegate?.didUpdateQueue(mpdClient: self, queue: self.queue)
+        if let status = self.status {
+          self.delegate?.didUpdateQueuePos(mpdClient: self, song: status.song)
+        }
       }
-    }
-    if mpdIdle.contains(.update) {
-      self.fetchStatus()
+      if mpdIdle.contains(.player) ||
+         mpdIdle.contains(.options) ||
+         mpdIdle.contains(.mixer) {
+        self.fetchStatus()
 
-      if self.status?.updating ?? false {
-        self.delegate?.willStartDatabaseUpdate(mpdClient: self)
-      } else {
-        self.delegate?.didFinishDatabaseUpdate(mpdClient: self)
+        if let status = self.status {
+          self.delegate?.didUpdateStatus(mpdClient: self, status: status)
+          self.delegate?.didUpdateQueuePos(mpdClient: self, song: status.song)
+        }
+      }
+      if mpdIdle.contains(.update) {
+        self.fetchStatus()
+
+        if self.status?.updating ?? false {
+          self.delegate?.willStartDatabaseUpdate(mpdClient: self)
+        } else {
+          self.delegate?.didFinishDatabaseUpdate(mpdClient: self)
+        }
+      }
+      if !mpdIdle.isEmpty {
+        self.idle()
       }
-    }
-    if !mpdIdle.isEmpty {
-      self.idle()
     }
   }
 }

Persephone/MPDClient/Extensions/MPDClient+Mixer.swift

@@ -0,0 +1,24 @@
+//
+//  MPDClient+Mixer.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2/16/20.
+//  Copyright © 2020 Dan Barber. All rights reserved.
+//
+
+import Foundation
+import mpdclient
+
+extension MPDClient {
+  func setVolume(to volume: Int) {
+    enqueueCommand(
+      command: .setVolume,
+      priority: .high,
+      userData: ["volume": volume]
+    )
+  }
+  
+  func sendSetVolume(to volume: Int) {
+    mpd_run_set_volume(connection, UInt32(volume))
+  }
+}

Persephone/MPDClient/Extensions/MPDClient+Queue.swift

@@ -19,27 +19,51 @@ extension MPDClient {
   }
 
   func playTrack(at queuePos: Int) {
-    enqueueCommand(command: .playTrack, userData: ["queuePos": queuePos])
+    enqueueCommand(
+      command: .playTrack,
+      forceIdle: true,
+      userData: ["queuePos": queuePos]
+    )
   }
 
   func appendSong(_ song: MPDSong) {
-    enqueueCommand(command: .appendSong, userData: ["song": song])
+    enqueueCommand(
+      command: .appendSong,
+      forceIdle: true,
+      userData: ["song": song]
+    )
   }
 
   func removeSong(at queuePos: Int) {
-    enqueueCommand(command: .removeSong, userData: ["queuePos": queuePos])
+    enqueueCommand(
+      command: .removeSong,
+      forceIdle: true,
+      userData: ["queuePos": queuePos]
+    )
   }
 
   func moveSongInQueue(at queuePos: Int, to newQueuePos: Int) {
-    enqueueCommand(command: .moveSongInQueue, userData: ["oldQueuePos": queuePos, "newQueuePos": newQueuePos])
+    enqueueCommand(
+      command: .moveSongInQueue,
+      forceIdle: true,
+      userData: ["oldQueuePos": queuePos, "newQueuePos": newQueuePos]
+    )
   }
 
   func addSongToQueue(songUri: String, at queuePos: Int) {
-    enqueueCommand(command: .addSongToQueue, userData: ["uri": songUri, "queuePos": queuePos])
+    enqueueCommand(
+      command: .addSongToQueue,
+      forceIdle: true,
+      userData: ["uri": songUri, "queuePos": queuePos]
+    )
   }
 
   func addAlbumToQueue(album: MPDAlbum, at queuePos: Int) {
-    enqueueCommand(command: .addAlbumToQueue, userData: ["album": album, "queuePos": queuePos])
+    enqueueCommand(
+      command: .addAlbumToQueue,
+      forceIdle: true,
+      userData: ["album": album, "queuePos": queuePos]
+    )
   }
 
   func sendPlayTrack(at queuePos: Int) {

Persephone/MPDClient/Extensions/MPDClient+Songs.swift

@@ -10,19 +10,80 @@ import Foundation
 import mpdclient
 
 extension MPDClient {
+  func fetchAlbumArt(
+    songUri: String,
+    imageData: Data?,
+    offset: Int32 = 0,
+    callback: @escaping (Data?) -> Void
+  ) {
+    enqueueCommand(
+      command: .fetchAlbumArt,
+      priority: .low,
+      userData: [
+        "songUri": songUri,
+        "callback": callback,
+        "imageData": imageData as Any,
+        "offset": offset,
+      ]
+    )
+  }
+  
   func searchSongs(_ terms: [MPDClient.MPDTag: String]) -> [MPDSong] {
     var songs: [MPDSong] = []
 
-    mpd_search_db_songs(self.connection, true)
+    mpd_search_db_songs(connection, true)
     for (tag, term) in terms {
-      mpd_search_add_tag_constraint(self.connection, MPD_OPERATOR_DEFAULT, tag.mpdTag(), term)
+      mpd_search_add_tag_constraint(connection, MPD_OPERATOR_DEFAULT, tag.mpdTag(), term)
     }
-    mpd_search_commit(self.connection)
+    mpd_search_commit(connection)
 
-    while let song = mpd_recv_song(self.connection) {
+    while let song = mpd_recv_song(connection) {
       songs.append(MPDSong(song))
     }
 
     return songs
   }
+  
+  func sendFetchAlbumArt(
+    forUri songUri: String,
+    imageData: Data?,
+    offset: Int32,
+    callback: @escaping (Data?) -> Void
+  ) -> Void {
+    var size: Int?
+    
+    mpd_send_albumart(connection, songUri, String(offset))
+    
+    guard let sizePair = mpd_recv_pair(connection) else {
+      mpd_connection_clear_error(connection)
+      return
+    }
+    size = Int(MPDPair(sizePair).value)
+    mpd_return_pair(connection, sizePair)
+
+    var data = imageData ?? Data(count: size!)
+          
+    let binaryPair = MPDPair(mpd_recv_pair(connection))
+    let chunkSize = Int(binaryPair.value)!
+    mpd_return_pair(connection, binaryPair.pair)
+    
+    _ = data[offset...].withUnsafeMutableBytes { (pointer) in
+      mpd_recv_binary(connection, pointer.baseAddress, chunkSize)
+    }
+    
+    guard mpd_response_finish(connection) else { return }
+    
+    let newOffset = offset + Int32(chunkSize)
+    
+    if newOffset < size! {
+      fetchAlbumArt(
+        songUri: songUri,
+        imageData: data,
+        offset: newOffset,
+        callback: callback
+      )
+    } else {
+      callback(data)
+    }
+  }
 }

Persephone/MPDClient/Extensions/MPDClient+Transport.swift

@@ -11,24 +11,42 @@ import mpdclient
 
 extension MPDClient {
   func playPause() {
-    enqueueCommand(command: .playPause)
+    enqueueCommand(
+      command: .playPause,
+      priority: .high,
+      forceIdle: true
+    )
   }
 
   func stop() {
-    enqueueCommand(command: .stop)
+    enqueueCommand(
+      command: .stop,
+      priority: .high,
+      forceIdle: true
+    )
   }
 
   func prevTrack() {
-    enqueueCommand(command: .prevTrack)
+    enqueueCommand(
+      command: .prevTrack,
+      priority: .high,
+      forceIdle: true
+    )
   }
 
   func nextTrack() {
-    enqueueCommand(command: .nextTrack)
+    enqueueCommand(
+      command: .nextTrack,
+      priority: .high,
+      forceIdle: true
+    )
   }
 
   func seekCurrentSong(timeInSeconds: Float) {
     enqueueCommand(
       command: .seekCurrentSong,
+      priority: .high,
+      forceIdle: true,
       userData: ["timeInSeconds": timeInSeconds]
     )
   }
@@ -36,6 +54,8 @@ extension MPDClient {
   func setShuffleState(shuffleState: Bool) {
     enqueueCommand(
       command: .setShuffleState,
+      priority: .high,
+      forceIdle: true,
       userData: ["shuffleState": shuffleState]
     )
   }
@@ -43,6 +63,8 @@ extension MPDClient {
   func setRepeatState(repeatState: Bool) {
     enqueueCommand(
       command: .setRepeatState,
+      priority: .high,
+      forceIdle: true,
       userData: ["repeatState": repeatState]
     )
   }

Persephone/MPDClient/Extensions/MPDClientWrapper.c

@@ -0,0 +1,15 @@
+//
+//  MPDClientWrapper.c
+//  Persephone
+//
+//  Created by Daniel Barber on 1/31/20.
+//  Copyright © 2020 Dan Barber. All rights reserved.
+//
+
+#include "MPDClientWrapper.h"
+
+int
+mpd_send_albumart(struct mpd_connection *connection, const char * uri, const char * offset)
+{
+  return mpd_send_command(connection, "albumart", uri, offset, NULL);
+}

Persephone/MPDClient/Extensions/MPDClientWrapper.h

@@ -0,0 +1,12 @@
+//
+//  MPDClientWrapper.h
+//  Persephone
+//
+//  Created by Daniel Barber on 1/31/20.
+//  Copyright © 2020 Dan Barber. All rights reserved.
+//
+
+#include <mpd/client.h>
+
+int
+mpd_send_albumart(struct mpd_connection *connection, const char * uri, const char * offset);

Persephone/MPDClient/Extensions/Persephone-Bridging-Header.h

@@ -0,0 +1,5 @@
+//
+//  Use this file to import your target's public headers that you would like to expose to Swift.
+//
+
+#import "MPDClientWrapper.h"

Persephone/MPDClient/MPDClient.swift

@@ -21,6 +21,8 @@ class MPDClient {
   var queue: [MPDSong] = []
 
   let commandQueue = OperationQueue()
+  
+  let idleLock = NSLock()
 
   init(withDelegate delegate: MPDClientDelegate?) {
     commandQueue.maxConcurrentOperationCount = 1

Persephone/MPDClient/Models/MPDAlbum.swift

@@ -12,8 +12,8 @@ extension MPDClient {
   struct MPDAlbum: Equatable {
     let title: String
     let artist: String
+    var firstSong: MPDSong?
     var date: String?
-    var path: String?
 
     static func == (lhs: MPDAlbum, rhs: MPDAlbum) -> Bool {
       return lhs.title == rhs.title &&

Persephone/MPDClient/Models/MPDCommand.swift

@@ -22,6 +22,8 @@ extension MPDClient {
 
     case setShuffleState
     case setRepeatState
+    
+    case setVolume
 
     // Database commands
     case updateDatabase
@@ -48,5 +50,8 @@ extension MPDClient {
     case playAlbum
     case getAlbumFirstSong
     case getAlbumSongs
+    
+    // Song commands
+    case fetchAlbumArt
   }
 }

Persephone/MPDClient/Models/MPDSong.swift

@@ -37,8 +37,7 @@ extension MPDClient {
       return MPDAlbum(
         title: getTag(.album),
         artist: artist,
-        date: date,
-        path: path
+        date: date
       )
     }
 
@@ -54,11 +53,6 @@ extension MPDClient {
       return getTag(.date)
     }
 
-    var path: String {
-      return NSString(string: uriString)
-        .deletingLastPathComponent
-    }
-
     func getTag(_ tagType: MPDTag) -> String {
       guard let tag = mpd_song_get_tag(song, tagType.mpdTag(), 0)
         else { return "" }

Persephone/MPDClient/Models/MPDStatus.swift

@@ -57,6 +57,10 @@ extension MPDClient {
     var repeatState: Bool {
       return mpd_status_get_repeat(status)
     }
+    
+    var volume: Int {
+      return Int(mpd_status_get_volume(status))
+    }
 
     var updating: Bool {
       let updating = mpd_status_get_update_id(status)

Persephone/Models/Album.swift

@@ -32,29 +32,6 @@ struct Album {
   var hash: String {
     return "\(title) - \(artist)".sha1()
   }
-
-  var coverArtFilenames: [String] {
-    return [
-      "cover.jpg",
-      "folder.jpg",
-      "\(artist) - \(title).jpg",
-      "cover.png",
-      "folder.png",
-      "\(artist) - \(title ).png",
-    ]
-  }
-
-  var coverArtFilePath: String? {
-    let musicDir = App.store.state.preferencesState.expandedMpdLibraryDir
-    guard let albumPath = mpdAlbum.path else { return nil }
-
-    return coverArtFilenames
-      .lazy
-      .map { "\(musicDir)/\(albumPath)/\($0)" }
-      .first {
-        FileManager.default.fileExists(atPath: $0)
-      }
-  }
 }
 
 extension Album: Equatable {

Persephone/Models/DraggedSong.swift

@@ -8,7 +8,8 @@
 
 struct DraggedSong: Codable {
   var type: DraggedSongType
-  var title: String?
-  var artist: String?
-  var cover: String?
+  var title: String
+  var artist: String
+  var album: String
+  var uri: String
 }

Persephone/Operations/CoverArtQueue.swift

@@ -1,23 +0,0 @@
-//
-//  CoverArtQueue.swift
-//  Persephone
-//
-//  Created by Daniel Barber on 2019/2/26.
-//  Copyright © 2019 Dan Barber. All rights reserved.
-//
-
-import AppKit
-
-class CoverArtQueue {
-  static let shared = CoverArtQueue()
-
-  let queue = DispatchQueue(label: "CoverArtQueue")
-  var lastDispatchedTime = DispatchTime(uptimeNanoseconds: 0) - 1
-
-  func addToQueue(workItem: DispatchWorkItem) {
-    let dispatchTime = max(lastDispatchedTime + 1, DispatchTime(uptimeNanoseconds: 0))
-    lastDispatchedTime = dispatchTime
-
-    queue.asyncAfter(deadline: dispatchTime, execute: workItem)
-  }
-}

Persephone/Services/CoverArtService.swift

@@ -0,0 +1,83 @@
+//
+//  CoverArtService.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2/3/20.
+//  Copyright © 2020 Dan Barber. All rights reserved.
+//
+
+import Foundation
+import PromiseKit
+import Kingfisher
+
+struct CoverArtService {
+  let song: Song
+  let provider: MPDAlbumArtImageDataProvider
+  
+  init(song: Song) {
+    self.song = song
+
+    provider = MPDAlbumArtImageDataProvider(
+      songUri: song.mpdSong.uriString,
+      cacheKey: song.album.hash
+    )
+  }
+  
+  func refreshAlbumListArt() -> Promise<Any> {
+    return Promise<Any> { seal in
+      _ = KingfisherManager.shared.retrieveImage(
+        with: .provider(provider),
+        options: [
+          .forceRefresh,
+          .memoryCacheExpiration(.never),
+          .processor(DownsamplingImageProcessor(size: .albumListCoverSize)),
+          .scaleFactor(2),
+        ]
+      ) { result in
+        seal.fulfill(result)
+      }
+    }
+  }
+  
+  func refreshCurrentlyPlayingArt() -> Promise<Any> {
+    return Promise<Any> { seal in
+      _ = KingfisherManager.shared.retrieveImage(
+        with: .provider(provider),
+        options: [
+          .forceRefresh,
+          .memoryCacheExpiration(.never),
+          .processor(DownsamplingImageProcessor(size: .currentlyPlayingCoverSize)),
+          .scaleFactor(2),
+          .callbackQueue(.mainAsync)
+        ]
+      ) { result in
+        seal.fulfill(result)
+      }
+    }
+  }
+  
+  func refreshQueueSongArt() -> Promise<Any> {
+    return Promise<Any> { seal in
+      _ = KingfisherManager.shared.retrieveImage(
+        with: .provider(provider),
+        options: [
+          .forceRefresh,
+          .memoryCacheExpiration(.never),
+          .processor(DownsamplingImageProcessor(size: .queueSongCoverSize)),
+          .scaleFactor(2),
+        ]
+      ) { result in
+        seal.fulfill(result)
+      }
+    }
+  }
+  
+  func refresh(callback: @escaping () -> Void?) {
+    _ = firstly {
+      when(fulfilled: refreshAlbumListArt(), refreshQueueSongArt(), refreshCurrentlyPlayingArt())
+    }.done { _, _, _ in
+      NotificationCenter.default.post(name: .didReloadAlbumArt, object: nil)
+      callback()
+    }
+  }
+}

Persephone/State/Actions/PlayerActions.swift

@@ -20,3 +20,7 @@ struct UpdateElapsedTimeAction: Action {
 struct UpdateStatusAction: Action {
   var status: MPDClient.MPDStatus
 }
+
+struct UpdateVolumeAction: Action {
+  var volume: Int
+}

Persephone/State/Actions/PreferencesActions.swift

@@ -16,10 +16,6 @@ struct UpdateServerPort: Action {
   var port: Int?
 }
 
-struct UpdateMPDLibraryDir: Action {
-  var mpdLibraryDir: String?
-}
-
 struct UpdateFetchMissingArtworkFromInternet: Action {
   var fetchMissingArtworkFromInternet: Bool
 }

Persephone/State/PlayerState.swift

@@ -16,6 +16,8 @@ struct PlayerState: StateType {
   var state: MPDClient.MPDStatus.State?
   var shuffleState: Bool = false
   var repeatState: Bool = false
+  
+  var volume: Int = 0
 
   var totalTime: UInt?
   var elapsedTimeMs: UInt?
@@ -23,10 +25,11 @@ struct PlayerState: StateType {
 
 extension PlayerState: Equatable {
   static func == (lhs: PlayerState, rhs: PlayerState) -> Bool {
-    return (lhs.state == rhs.state) &&
-      (lhs.totalTime == rhs.totalTime) &&
-      (lhs.elapsedTimeMs == rhs.elapsedTimeMs) &&
-      (lhs.shuffleState == rhs.shuffleState) &&
-      (lhs.repeatState == rhs.repeatState)
+    return lhs.state == rhs.state &&
+      lhs.totalTime == rhs.totalTime &&
+      lhs.elapsedTimeMs == rhs.elapsedTimeMs &&
+      lhs.shuffleState == rhs.shuffleState &&
+      lhs.repeatState == rhs.repeatState &&
+      lhs.volume == rhs.volume
   }
 }

Persephone/State/PreferencesState.swift

@@ -13,17 +13,6 @@ struct PreferencesState: StateType, Equatable {
   let preferences = UserDefaults.standard
 
   var mpdServer: MPDServer
-  let mpdLibraryDirDefault = "~/Music"
-
-  var mpdLibraryDir: String?
-
-  var mpdLibraryDirOrDefault: String {
-    return mpdLibraryDir ?? mpdLibraryDirDefault
-  }
-
-  var expandedMpdLibraryDir: String {
-    return NSString(string: mpdLibraryDirOrDefault).expandingTildeInPath
-  }
 
   var fetchMissingArtworkFromInternet: Bool
 
@@ -32,7 +21,6 @@ struct PreferencesState: StateType, Equatable {
       host: preferences.string(forKey: "mpdHost"),
       port: preferences.value(forKey: "mpdPort") as? Int
     )
-    self.mpdLibraryDir = preferences.string(forKey: "mpdLibraryDir")
     self.fetchMissingArtworkFromInternet = preferences.bool(
       forKey: "fetchMissingArtworkFromInternet"
     )
@@ -45,7 +33,6 @@ struct PreferencesState: StateType, Equatable {
     } else {
       preferences.removeObject(forKey: "mpdPort")
     }
-    preferences.set(mpdLibraryDir, forKey: "mpdLibraryDir")
     preferences.set(fetchMissingArtworkFromInternet, forKey: "fetchMissingArtworkFromInternet")
   }
 }

Persephone/State/Reducers/PlayerReducer.swift

@@ -20,6 +20,7 @@ func playerReducer(action: Action, state: PlayerState?) -> PlayerState {
     state.elapsedTimeMs = action.status.elapsedTimeMs
     state.shuffleState = action.status.shuffleState
     state.repeatState = action.status.repeatState
+    state.volume = action.status.volume
 
     if state.state == .playing {
       App.trackTimer.start(elapsedTimeMs: state.elapsedTimeMs)

Persephone/State/Reducers/PreferencesReducer.swift

@@ -20,9 +20,6 @@ func preferencesReducer(action: Action, state: PreferencesState?) -> Preferences
   case let action as UpdateServerPort:
     state.mpdServer.port = action.port
 
-  case let action as UpdateMPDLibraryDir:
-    state.mpdLibraryDir = action.mpdLibraryDir
-
   case is SavePreferences:
     state.save()