wip: modularize once again

jack/src/jack_audio.rs

@@ -0,0 +1,26 @@
+use crate::*;
+
+/// Implement [Audio]: provide JACK callbacks.
+#[macro_export] macro_rules! audio {
+    (|$self:ident:$Struct:ident$(<$($L:lifetime),*$($T:ident$(:$U:path)?),*>)?,$c:ident,$s:ident|$cb:expr) => {
+        impl $(<$($L),*$($T $(: $U)?),*>)? Audio for $Struct $(<$($L),*$($T),*>)? {
+            #[inline] fn process (&mut $self, $c: &Client, $s: &ProcessScope) -> Control { $cb }
+        }
+    }
+}
+
+/// Trait for thing that has a JACK process callback.
+pub trait Audio: Send + Sync {
+    fn process (&mut self, _: &Client, _: &ProcessScope) -> Control {
+        Control::Continue
+    }
+    fn callback (
+        state: &Arc<RwLock<Self>>, client: &Client, scope: &ProcessScope
+    ) -> Control where Self: Sized {
+        if let Ok(mut state) = state.write() {
+            state.process(client, scope)
+        } else {
+            Control::Quit
+        }
+    }
+}