upgrade go-mpris-server; gracefully handle no dbus connection

backend/mpris.go

@@ -18,8 +18,9 @@ var (
 	_ types.OrgMprisMediaPlayer2Adapter       = (*MPRISHandler)(nil)
 	_ types.OrgMprisMediaPlayer2PlayerAdapter = (*MPRISHandler)(nil)
 )
+
 var (
-	notImplemented = errors.New("not implemented")
+	errNotImplemented = errors.New("not implemented")
 )
 
 type MPRISHandler struct {
@@ -33,6 +34,7 @@ type MPRISHandler struct {
 	// Function to look up the artwork URL for a given track ID
 	ArtURLLookup func(trackID string) (string, error)
 
+	connErr    error
 	playerName string
 	p          *player.Player
 	pm         *PlaybackManager
@@ -41,20 +43,26 @@ type MPRISHandler struct {
 }
 
 func NewMPRISHandler(playerName string, p *player.Player, pm *PlaybackManager) *MPRISHandler {
-	m := &MPRISHandler{playerName: playerName, p: p, pm: pm}
+	m := &MPRISHandler{playerName: playerName, p: p, pm: pm, connErr: errors.New("not started")}
 	m.s = server.NewServer(playerName, m, m)
 	m.evt = events.NewEventHandler(m.s)
 
 	m.p.OnSeek(func() {
+		if m.connErr == nil {
 			pos := secondsToMicroseconds(m.p.GetStatus().TimePos)
 			m.evt.Player.OnSeek(pos)
+		}
 	})
 	m.pm.OnSongChange(func(_, _ *mediaprovider.Track) {
+		if m.connErr == nil {
 			m.evt.Player.OnTitle()
+		}
 	})
 	emitPlayStatus := func() {
+		if m.connErr == nil {
 			m.evt.Player.OnPlayPause()
 		}
+	}
 	m.p.OnStopped(emitPlayStatus)
 	m.p.OnPlaying(emitPlayStatus)
 	m.p.OnPaused(emitPlayStatus)
@@ -64,12 +72,19 @@ func NewMPRISHandler(playerName string, p *player.Player, pm *PlaybackManager) *
 
 // Starts listening for MPRIS events.
 func (m *MPRISHandler) Start() {
-	go m.s.Listen()
+	m.connErr = nil
+	go func() {
+		// exits early with err if unable to establish D-Bus connection
+		m.connErr = m.s.Listen()
+	}()
 }
 
 // Stops listening for MPRIS events and releases any D-Bus resources.
 func (m *MPRISHandler) Shutdown() {
+	if m.connErr == nil {
 		m.s.Stop()
+		m.connErr = errors.New("stopped")
+	}
 }
 
 // OrgMprisMediaPlayer2Adapter implementation
@@ -152,11 +167,11 @@ func (m *MPRISHandler) Seek(offset types.Microseconds) error {
 }
 
 func (m *MPRISHandler) SetPosition(trackId string, position types.Microseconds) error {
-	return notImplemented
+	return errNotImplemented
 }
 
 func (m *MPRISHandler) OpenUri(uri string) error {
-	return notImplemented
+	return errNotImplemented
 }
 
 func (m *MPRISHandler) PlaybackStatus() (types.PlaybackStatus, error) {
@@ -176,7 +191,7 @@ func (m *MPRISHandler) Rate() (float64, error) {
 }
 
 func (m *MPRISHandler) SetRate(float64) error {
-	return notImplemented
+	return errNotImplemented
 }
 
 func (m *MPRISHandler) Metadata() (types.Metadata, error) {
@@ -214,7 +229,7 @@ func (m *MPRISHandler) Volume() (float64, error) {
 }
 
 func (m *MPRISHandler) SetVolume(float64) error {
-	return notImplemented
+	return errNotImplemented
 }
 
 func (m *MPRISHandler) Position() (int64, error) {

go.mod

@@ -9,8 +9,10 @@ require (
 	github.com/dweymouth/go-mpv v0.0.0-20230406003141-7f1858e503ee
 	github.com/dweymouth/go-subsonic v0.0.0-20230614154319-792d18c75fb4
 	github.com/fsnotify/fsnotify v1.6.0
+	github.com/godbus/dbus/v5 v5.1.0
 	github.com/google/uuid v1.3.0
 	github.com/pelletier/go-toml/v2 v2.0.8
+	github.com/quarckster/go-mpris-server v1.0.1
 	github.com/zalando/go-keyring v0.2.1
 	golang.org/x/net v0.0.0-20220722155237-a158d28d115b
 )
@@ -27,13 +29,11 @@ require (
 	github.com/go-gl/gl v0.0.0-20211210172815-726fda9656d6 // indirect
 	github.com/go-gl/glfw/v3.3/glfw v0.0.0-20221017161538-93cebf72946b // indirect
 	github.com/go-text/typesetting v0.0.0-20230405155246-bf9c697c6e16 // indirect
-	github.com/godbus/dbus/v5 v5.1.0 // indirect
 	github.com/goki/freetype v0.0.0-20220119013949-7a161fd3728c // indirect
 	github.com/gopherjs/gopherjs v1.17.2 // indirect
 	github.com/jsummers/gobmp v0.0.0-20151104160322-e2ba15ffa76e // indirect
 	github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/quarckster/go-mpris-server v1.0.0 // indirect
 	github.com/srwiley/oksvg v0.0.0-20220731023508-a61f04f16b76 // indirect
 	github.com/srwiley/rasterx v0.0.0-20210519020934-456a8d69b780 // indirect
 	github.com/stretchr/testify v1.8.3 // indirect

go.sum

@@ -265,8 +265,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/posener/complete v1.1.1/go.mod h1:em0nMJCgc9GFtwrmVmEMR/ZL6WyhyjMBndrE9hABlRI=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
-github.com/quarckster/go-mpris-server v1.0.0 h1:9EKh8Ink7d3OigBLXGlRJ0jDJi+O6T/XMroA5Gl4c5Q=
-github.com/quarckster/go-mpris-server v1.0.0/go.mod h1:2b4IdrpnEoEfU+6fQKjYhAgdvsiz4JxmTpDAUrMJVO4=
+github.com/quarckster/go-mpris-server v1.0.1 h1:JAbVBJK1ijjwEH4gfaOtwfElDVuaBPnWyi8rZJEHOxc=
+github.com/quarckster/go-mpris-server v1.0.1/go.mod h1:2b4IdrpnEoEfU+6fQKjYhAgdvsiz4JxmTpDAUrMJVO4=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=