Added easier getter for device kind.

device.go

@@ -22,6 +22,10 @@ type Device interface {
 	Close()
 }
 
+type kindGetter interface {
+	GetKind() Kind
+}
+
 type createOutputDeviceFunc func(settings Settings) (Device, error)
 
 type deviceDetails struct {
@@ -32,8 +36,8 @@ type deviceDetails struct {
 
 // GetKind returns the kind for the passed in device
 func GetKind(d Device) Kind {
-	if dev, ok := d.(*deviceDetails); ok {
-		return dev.kind
+	if dev, ok := d.(kindGetter); ok {
+		return dev.GetKind()
 	}
 	return KindNone
 }
@@ -50,15 +54,14 @@ func CreateOutputDevice(settings Settings) (Device, error) {
 		if err != nil {
 			return nil, err
 		}
-		dev.(*device).deviceDetails = details
 		return dev, nil
 	}
 
 	return nil, errors.Wrap(ErrDeviceNotSupported, settings.Name)
 }
 
 type device struct {
-	deviceDetails
+	Device
 
 	onRowOutput DisplayFunc
 }

device_directsound.go

@@ -26,6 +26,10 @@ type dsoundDevice struct {
 	mix mixing.Mixer
 }
 
+func (d *dsoundDevice) GetKind() Kind {
+	return KindSoundCard
+}
+
 func newDSoundDevice(settings Settings) (Device, error) {
 	d := dsoundDevice{
 		device: device{

device_file.go

@@ -16,6 +16,10 @@ type fileDevice struct {
 	device
 }
 
+func (d *fileDevice) GetKind() Kind {
+	return KindFile
+}
+
 // Name returns the device name
 func (d *fileDevice) Name() string {
 	return fileName

device_pulseaudio.go

@@ -19,6 +19,10 @@ type pulseaudioDevice struct {
 	pa  *pulseaudio.Client
 }
 
+func (d *pulseaudioDevice) GetKind() Kind {
+	return KindSoundCard
+}
+
 func newPulseAudioDevice(settings Settings) (Device, error) {
 	d := pulseaudioDevice{
 		device: device{

device_winmm.go

@@ -20,6 +20,10 @@ type winmmDevice struct {
 	waveout *winmm.WaveOut
 }
 
+func (d *winmmDevice) GetKind() Kind {
+	return KindSoundCard
+}
+
 func newWinMMDevice(settings Settings) (Device, error) {
 	d := winmmDevice{
 		device: device{