device/webcam: implement IsRunning method for webcam

device/webcam/webcam.go

@@ -67,6 +67,7 @@ type Webcam struct {
 	cfg       config.Config
 	cmd       *exec.Cmd
 	done      chan struct{}
+	isRunning bool
 }
 
 // New returns a new Webcam.
@@ -161,6 +162,8 @@ func (w *Webcam) Start() error {
 		return fmt.Errorf("could not pipe command error: %w", err)
 	}
 
+	w.isRunning = true
+
 	go func() {
 		for {
 			select {
@@ -202,7 +205,12 @@ func (w *Webcam) Stop() error {
 	if err != nil {
 		return fmt.Errorf("could not kill ffmpeg process: %w", err)
 	}
-	return w.out.Close()
+	err = w.out.Close()
+	if err == nil {
+		w.isRunning = false
+		return nil
+	}
+	return err
 }
 
 // Read implements io.Reader. If the pipe is nil a read error is returned.
@@ -215,6 +223,5 @@ func (w *Webcam) Read(p []byte) (int, error) {
 
 // IsRunning is used to determine if the webcam is running.
 func (w *Webcam) IsRunning() bool {
-	panic("not implemented")
-	return false
+	return w.isRunning
 }