feat!: rewrote the GUI and model for better testability

The Model was getting unmaintanable mess. This is an attempt to refactor/rewrite the Model so that data of certain type is exposed in standardized way, offering certain standard manipulations for that data type, and on the GUI side, certain standard widgets to tied to that data.

This rewrite closes #72, #106 and #120.

cmd/sointu-play/main.go

@@ -87,7 +87,7 @@ func main() {
 				return fmt.Errorf("the song could not be parsed as .json (%v) or .yml (%v)", errJSON, errYaml)
 			}
 		}
-		buffer, err := sointu.Play(bridge.NativeSynther{}, song) // render the song to calculate its length
+		buffer, err := sointu.Play(bridge.NativeSynther{}, song, nil) // render the song to calculate its length
 		if err != nil {
 			return fmt.Errorf("sointu.Play failed: %v", err)
 		}

cmd/sointu-track/main.go

@@ -33,16 +33,16 @@ var memprofile = flag.String("memprofile", "", "write memory profile to `file`")
 
 func main() {
 	flag.Parse()
+	var f *os.File
 	if *cpuprofile != "" {
-		f, err := os.Create(*cpuprofile)
+		var err error
+		f, err = os.Create(*cpuprofile)
 		if err != nil {
 			log.Fatal("could not create CPU profile: ", err)
 		}
-		defer f.Close() // error handling omitted for example
 		if err := pprof.StartCPUProfile(f); err != nil {
 			log.Fatal("could not start CPU profile: ", err)
 		}
-		defer pprof.StopCPUProfile()
 	}
 	audioContext, err := oto.NewContext()
 	if err != nil {
@@ -50,15 +50,12 @@ func main() {
 		os.Exit(1)
 	}
 	defer audioContext.Close()
-	modelMessages := make(chan interface{}, 1024)
-	playerMessages := make(chan tracker.PlayerMessage, 1024)
 	recoveryFile := ""
 	if configDir, err := os.UserConfigDir(); err == nil {
 		recoveryFile = filepath.Join(configDir, "Sointu", "sointu-track-recovery")
 	}
-	model := tracker.NewModel(modelMessages, playerMessages, recoveryFile)
-	player := tracker.NewPlayer(cmd.MainSynther, playerMessages, modelMessages)
-	tracker := gioui.NewTracker(model, cmd.MainSynther)
+	model, player := tracker.NewModelPlayer(cmd.MainSynther, recoveryFile)
+	tracker := gioui.NewTracker(model)
 	output := audioContext.Output()
 	defer output.Close()
 	go func() {
@@ -71,6 +68,10 @@ func main() {
 	}()
 	go func() {
 		tracker.Main()
+		if *cpuprofile != "" {
+			pprof.StopCPUProfile()
+			f.Close()
+		}
 		if *memprofile != "" {
 			f, err := os.Create(*memprofile)
 			if err != nil {

cmd/sointu-vsti/main.go

@@ -54,19 +54,16 @@ func init() {
 		version = int32(100)
 	)
 	vst2.PluginAllocator = func(h vst2.Host) (vst2.Plugin, vst2.Dispatcher) {
-		modelMessages := make(chan interface{}, 1024)
-		playerMessages := make(chan tracker.PlayerMessage, 1024)
 		recoveryFile := ""
 		if configDir, err := os.UserConfigDir(); err == nil {
 			randBytes := make([]byte, 16)
 			rand.Read(randBytes)
 			recoveryFile = filepath.Join(configDir, "Sointu", "sointu-vsti-recovery-"+hex.EncodeToString(randBytes))
 		}
-		model := tracker.NewModel(modelMessages, playerMessages, recoveryFile)
-		player := tracker.NewPlayer(cmd.MainSynther, playerMessages, modelMessages)
-		tracker := gioui.NewTracker(model, cmd.MainSynther)
-		tracker.SetInstrEnlarged(true) // start the vsti with the instrument editor enlarged
-		go tracker.Main()
+		model, player := tracker.NewModelPlayer(cmd.MainSynther, recoveryFile)
+		t := gioui.NewTracker(model)
+		tracker.Bool{BoolData: (*tracker.InstrEnlarged)(model)}.Set(true)
+		go t.Main()
 		context := VSTIProcessContext{host: h}
 		buf := make(sointu.AudioBuffer, 1024)
 		return vst2.Plugin{
@@ -110,14 +107,16 @@ func init() {
 					}
 				},
 				CloseFunc: func() {
-					tracker.Quit(true)
-					tracker.WaitQuitted()
+					t.Exec() <- func() { t.ForceQuit().Do() }
+					t.WaitQuitted()
 				},
 				GetChunkFunc: func(isPreset bool) []byte {
-					return tracker.SafeMarshalRecovery()
+					retChn := make(chan []byte)
+					t.Exec() <- func() { retChn <- t.MarshalRecovery() }
+					return <-retChn
 				},
 				SetChunkFunc: func(data []byte, isPreset bool) {
-					tracker.SafeUnmarshalRecovery(data)
+					t.Exec() <- func() { t.UnmarshalRecovery(data) }
 				},
 			}