wip: refactor arranger to device

crates/engine/src/midi/midi_out.rs

@@ -0,0 +1,33 @@
+use crate::*;
+
+impl<T: Has<Vec<JackMidiOut>>> HasMidiOuts for T {
+    fn midi_outs (&self) -> &Vec<JackMidiOut> {
+        self.get()
+    }
+    fn midi_outs_mut (&mut self) -> &mut Vec<JackMidiOut> {
+        self.get_mut()
+    }
+}
+
+
+/// Trait for thing that may output MIDI.
+pub trait HasMidiOuts {
+    fn midi_outs (&self) -> &Vec<JackMidiOut>;
+    fn midi_outs_mut (&mut self) -> &mut Vec<JackMidiOut>;
+    fn midi_outs_with_sizes <'a> (&'a self) ->
+        impl Iterator<Item=(usize, &Arc<str>, &[PortConnect], usize, usize)> + Send + Sync + 'a
+    {
+        let mut y = 0;
+        self.midi_outs().iter().enumerate().map(move|(i, output)|{
+            let height = 1 + output.conn().len();
+            let data   = (i, output.name(), output.conn(), y, y + height);
+            y += height;
+            data
+        })
+    }
+    fn midi_out_add (&mut self, jack: &Jack) -> Usually<()> {
+        let index = self.midi_outs().len();
+        self.midi_outs_mut().push(JackMidiOut::new(&jack, &format!("{index}/M"), &[])?);
+        Ok(())
+    }
+}