more appmode logic

crates/app/src/model.rs

@@ -363,6 +363,38 @@ has_player!(|self: Track|self.player);
 
 impl Track {
     pub const MIN_WIDTH: usize = 9;
+    /// Create a new track containing a sequencer.
+    pub fn new_sequencer () -> Self {
+        let mut track = Self::default();
+        track.devices.push(Device::Sequencer(MidiPlayer::default()));
+        track
+    }
+    /// Create a new track containing a sequencer and sampler.
+    pub fn new_groovebox (
+        jack:       &Jack,
+        midi_from:  &[PortConnect],
+        audio_from: &[&[PortConnect];2],
+        audio_to:   &[&[PortConnect];2],
+    ) -> Usually<Self> {
+        let mut track = Self::new_sequencer();
+        track.devices.push(Device::Sampler(
+            Sampler::new(jack, &"sampler", midi_from, audio_from, audio_to)?
+        ));
+        Ok(track)
+    }
+    /// Create a new track containing a sampler.
+    pub fn new_sampler (
+        jack:       &Jack,
+        midi_from:  &[PortConnect],
+        audio_from: &[&[PortConnect];2],
+        audio_to:   &[&[PortConnect];2],
+    ) -> Usually<Self> {
+        let mut track = Self::default();
+        track.devices.push(Device::Sampler(
+            Sampler::new(jack, &"sampler", midi_from, audio_from, audio_to)?
+        ));
+        Ok(track)
+    }
     pub fn width_inc (&mut self) {
         self.width += 1;
     }