Fix #614: Update go-upnpcast for device discovery fix

backend/playbackengine.go

@@ -102,7 +102,6 @@ type playbackEngine struct {
 	onPaused           []func()
 	onStopped          []func()
 	onPlaying          []func()
-	onPlayerChange     []func()
 	onQueueChange      []func()
 }
 
@@ -171,10 +170,6 @@ func (p *playbackEngine) unregisterPlayerCallbacks(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.CurrentPlayer().GetStatus()
@@ -209,7 +204,6 @@ func (p *playbackEngine) SetPlayer(pl player.BasePlayer) error {
 		p.playTrackAt(p.nowPlayingIdx, p.pendingPlayerChangeStatus.TimePos)
 		p.pendingPlayerChange = false
 	}
-	p.invokeNoArgCallbacks(p.onPlayerChange)
 	vol := pl.GetVolume()
 	if oldVol != vol {
 		for _, cb := range p.onVolumeChange {

backend/playbackmanager.go

@@ -37,6 +37,7 @@ type PlaybackManager struct {
 	currentRemotePlayer *RemotePlaybackDevice
 
 	onWaveformImgUpdate []func(*WaveformImage)
+	onPlayerChange      []func()
 
 	lastPlayTime         float64
 	lastPlayingID        string
@@ -252,6 +253,14 @@ func (p *PlaybackManager) CurrentRemotePlayer() *RemotePlaybackDevice {
 }
 
 func (p *PlaybackManager) SetRemotePlayer(rp *RemotePlaybackDevice) error {
+	// Even in case of failure, call onPlayerChange callbacks to update UI
+	// (such as enabling/disabling cast button)
+	defer func() {
+		for _, cb := range p.onPlayerChange {
+			cb()
+		}
+	}()
+
 	p.cmdQueue.Clear()
 	if rp == nil {
 		if err := p.engine.SetPlayer(p.localPlayer); err != nil {
@@ -278,7 +287,7 @@ func (p *PlaybackManager) CurrentPlayer() player.BasePlayer {
 }
 
 func (p *PlaybackManager) OnPlayerChange(cb func()) {
-	p.engine.onPlayerChange = append(p.engine.onPlayerChange, cb)
+	p.onPlayerChange = append(p.onPlayerChange, cb)
 }
 
 func (p *PlaybackManager) OnWaveformImgUpdate(cb func(*WaveformImage)) {