disable cast button while player switch in progress

backend/playbackengine.go

@@ -142,6 +142,10 @@ func (p *playbackEngine) registerPlayerCallbacks(pl player.BasePlayer) {
 }
 
 func (p *playbackEngine) SetPlayer(pl player.BasePlayer) error {
+	// even if we don't successfully change players,
+	// make sure UI updates if needed (eg enabling cast button)
+	defer p.invokeNoArgCallbacks(p.onPlayerChange)
+
 	needToUnpause := false
 
 	stat := p.PlayerStatus()

ui/controller/controller.go

@@ -151,10 +151,11 @@ func (m *Controller) HaveModal() bool {
 	return m.haveModal
 }
 
-func (m *Controller) ShowCastMenu() {
+func (m *Controller) ShowCastMenu(onPendingPlayerChange func()) {
 	rp := m.App.PlaybackManager.CurrentRemotePlayer()
 	devices := m.App.PlaybackManager.RemotePlayers()
 	local := fyne.NewMenuItem(lang.L("Local player"), func() {
+		onPendingPlayerChange()
 		go func() {
 			if err := m.App.PlaybackManager.SetRemotePlayer(nil); err != nil {
 				fyne.Do(func() { m.ToastProvider.ShowErrorToast("Failed to disconnect from remote player") })
@@ -168,6 +169,7 @@ func (m *Controller) ShowCastMenu() {
 	for _, d := range devices {
 		_d := d
 		item := fyne.NewMenuItem(d.Name, func() {
+			onPendingPlayerChange()
 			go func() {
 				if err := m.App.PlaybackManager.SetRemotePlayer(&_d); err != nil {
 					fyne.Do(func() { m.ToastProvider.ShowErrorToast("Failed to connect to " + _d.Name) })

ui/widgets/auxcontrols.go

@@ -98,7 +98,12 @@ func (a *AuxControls) SetLoopMode(mode backend.LoopMode) {
 	}
 }
 
+func (a *AuxControls) DisableCastButton() {
+	a.cast.Disable()
+}
+
 func (a *AuxControls) SetIsRemotePlayer(isRemote bool) {
+	a.cast.Enable()
 	a.cast.Highlighted = isRemote
 	a.cast.Refresh()
 }
@@ -115,8 +120,10 @@ func (a *AuxControls) OnShowPlayQueue(f func()) {
 	a.showQueue.OnTapped = f
 }
 
-func (a *AuxControls) OnShowCastMenu(f func()) {
+func (a *AuxControls) OnShowCastMenu(f func(func())) {
-	a.cast.OnTapped = f
+	a.cast.OnTapped = func() {
+		f(a.DisableCastButton)
+	}
 }
 
 type volumeSlider struct {