systematizing jack handlers

src/device/mixer.rs

@@ -2,7 +2,7 @@ use crate::prelude::*;
 
 pub struct Mixer {
     name:            String,
-    jack:            Jack<Notifications>,
+    jack:            Jack<MixerJack>,
     tracks:          Vec<Track>,
     selected_track:  usize,
     selected_column: usize,
@@ -14,14 +14,9 @@ impl Mixer {
             name,
             ClientOptions::NO_START_SERVER
         )?;
-        let jack = client.activate_async(
-            Notifications,
-            ClosureProcessHandler::new(Box::new(
-                move |_: &Client, _: &ProcessScope| -> Control {
-                    Control::Continue
-                }) as Box<dyn FnMut(&Client, &ProcessScope)->Control + Send>
-            )
-        )?;
+        let jack = MixerJack.activate(client, ClosureProcessHandler::new(Box::new(
+            move|client: &Client, scope: &ProcessScope|process(client, scope)
+        ) as BoxedProcessHandler))?;
         Ok(DynamicDevice::new(render, handle, |_|{}, Self {
             name: name.into(),
             selected_column: 0,
@@ -41,6 +36,13 @@ impl Mixer {
     }
 }
 
+pub fn process (
+    client: &Client,
+    scope:  &ProcessScope
+) -> Control {
+    Control::Continue
+}
+
 pub fn render (state: &Mixer, buf: &mut Buffer, mut area: Rect)
     -> Usually<Rect>
 {
@@ -211,9 +213,17 @@ impl Track {
     }
 }
 
-pub struct Notifications;
+pub struct MixerJack;
 
-impl NotificationHandler for Notifications {
+impl MixerJack {
+    fn activate <P> (self, client: Client, handler: P) -> Usually<AsyncClient<Self, P>>
+        where P: 'static + Send + ::jack::ProcessHandler
+    {
+        Ok(client.activate_async(self, handler)?)
+    }
+}
+
+impl NotificationHandler for MixerJack {
     fn thread_init (&self, _: &Client) {
     }
 
@@ -254,7 +264,7 @@ impl NotificationHandler for Notifications {
     //fn handle (&mut self, engine: &mut TUI<W>) -> Result<Option<bool>> {
         //Ok(None)
     //}
-//}
+//
 
 //impl<W: Write> Output<TUI<W>, [u16;2]> for Mixer {
     //fn render (&self, envine: &mut TUI<W>) -> Result<Option<[u16;2]>> {