i dont know why that worked

src/device/transport.rs

@@ -2,21 +2,19 @@ use crate::prelude::*;
 
 pub struct Transport {
     name:      String,
-    transport: Option<::jack::Transport>,
-    bpm:       f64,
+    transport: ::jack::Transport,
     timesig:   (f32, f32),
+    bpm:       f64,
 }
 
 impl Transport {
-    pub fn new ()
-        -> Result<DynamicDevice<Self>, Box<dyn Error>>
-    {
-        //let transport = client.transport();
-        Ok(DynamicDevice::new(render, handle, |_|{}, Self {
-            name:      "Transport".into(),
-            bpm:       113.0,
+    pub fn new (name: &str) -> Result<DynamicDevice<Self>, Box<dyn Error>> {
+        let (client, _) = Client::new(name, ClientOptions::NO_START_SERVER)?;
+        Ok(DynamicDevice::new(render, handle, process, Self {
+            name:      name.into(),
+            transport: client.transport(),
             timesig:   (4.0, 4.0),
-            transport: None,
+            bpm:       113.0,
         }))
     }
 
@@ -24,7 +22,7 @@ impl Transport {
     }
 
     pub fn play_or_pause (&mut self) -> Result<(), Box<dyn Error>> {
-        match self.transport.as_ref().unwrap().query_state()? {
+        match self.transport.query_state()? {
             TransportState::Stopped => self.play(),
             TransportState::Rolling => self.stop(),
             _ => Ok(())
@@ -32,14 +30,18 @@ impl Transport {
     }
 
     pub fn play (&mut self) -> Result<(), Box<dyn Error>> {
-        Ok(self.transport.as_ref().unwrap().start()?)
+        Ok(self.transport.start()?)
     }
 
     pub fn stop (&mut self) -> Result<(), Box<dyn Error>> {
-        Ok(self.transport.as_ref().unwrap().stop()?)
+        Ok(self.transport.stop()?)
     }
 }
 
+pub fn process (state: &mut Transport, client: &Client, scope: &ProcessScope) -> Control {
+    Control::Continue
+}
+
 pub fn render (state: &Transport, buf: &mut Buffer, mut area: Rect)
     -> Usually<Rect>
 {
@@ -220,7 +222,7 @@ pub fn render (state: &Transport, buf: &mut Buffer, mut area: Rect)
     //Ok(())
 //}
 
-pub fn handle (state: &mut Transport, event: &EngineEvent) -> Result<(), Box<dyn Error>> {
+pub fn handle (state: &mut Transport, event: &AppEvent) -> Result<(), Box<dyn Error>> {
     Ok(())
 }
 
@@ -231,9 +233,9 @@ pub const ACTIONS: [(&'static str, &'static str);4] = [
     ("(Shift-)Space", "⯈ Play/pause"),
 ];
 
-struct Notifications;
+struct TransportJack;
 
-impl NotificationHandler for Notifications {
+impl NotificationHandler for TransportJack {
     fn thread_init (&self, _: &Client) {
     }