ensure casting playback stops when quitting app

backend/app.go

@@ -463,7 +463,7 @@ func (a *App) Shutdown() {
 		a.WinSMTC.Shutdown()
 	}
 	a.PlaybackManager.DisableCallbacks()
-	a.PlaybackManager.Stop() // will trigger scrobble check
+	a.PlaybackManager.Shutdown() // will trigger scrobble check
 	a.cancel()
 	a.LocalPlayer.Destroy()
 }

backend/playbackcommands.go

@@ -31,10 +31,11 @@ const (
 )
 
 type playbackCommand struct {
-	Type playbackCommandType
+	Type   playbackCommandType
-	Arg  any
+	Arg    any
-	Arg2 any
+	Arg2   any
-	Arg3 any
+	Arg3   any
+	OnDone func()
 }
 
 // playbackCommandQueue is a queue to accumulate player commands from the UI
@@ -65,6 +66,13 @@ func (c *playbackCommandQueue) Stop() {
 		playbackCommand{Type: cmdStop})
 }
 
+func (c *playbackCommandQueue) StopAndWait() {
+	done := make(chan struct{})
+	c.filterCommandsAndAdd([]playbackCommandType{cmdContinue, cmdPause, cmdStop},
+		playbackCommand{Type: cmdStop, OnDone: func() { close(done) }})
+	<-done
+}
+
 func (c *playbackCommandQueue) Continue() {
 	c.filterCommandsAndAdd([]playbackCommandType{cmdContinue, cmdPause, cmdStop},
 		playbackCommand{Type: cmdContinue})

backend/playbackmanager.go

@@ -512,6 +512,10 @@ func (p *PlaybackManager) Stop() {
 	p.cmdQueue.Stop()
 }
 
+func (p *PlaybackManager) Shutdown() {
+	p.cmdQueue.StopAndWait()
+}
+
 func (p *PlaybackManager) Pause() {
 	p.cmdQueue.Pause()
 }
@@ -662,6 +666,9 @@ func (p *PlaybackManager) runCmdQueue(ctx context.Context) {
 					mpv.ForceRestartPlayback()
 				}
 			}
+			if c.OnDone != nil {
+				c.OnDone()
+			}
 		}
 	}
 }