wip: build arranger out of freestanding functions

app/src/view/view_track.rs

@@ -0,0 +1,56 @@
+use crate::*;
+
+pub(crate) fn per_track_top <'a, T: Content<TuiOut> + 'a, U: TracksSizes<'a>> (
+    width:    u16,
+    tracks:   impl Fn() -> U + Send + Sync + 'a,
+    callback: impl Fn(usize, &'a Track)->T + Send + Sync + 'a
+) -> impl Content<TuiOut> + 'a {
+    Align::x(Tui::bg(Reset, Map::new(tracks, move|(index, track, x1, x2), _|{
+        let width = (x2 - x1) as u16;
+        map_east(x1 as u16, width, Fixed::x(width, Tui::fg_bg(
+            track.color.lightest.rgb,
+            track.color.base.rgb,
+            callback(index, track)
+        )))
+    })))
+}
+
+pub(crate) fn per_track <'a, T: Content<TuiOut> + 'a, U: TracksSizes<'a>> (
+    width:    u16,
+    tracks:   impl Fn() -> U + Send + Sync + 'a,
+    callback: impl Fn(usize, &'a Track)->T + Send + Sync + 'a
+) -> impl Content<TuiOut> + 'a {
+    per_track_top(width, tracks, move|index, track|Fill::y(Align::y(callback(index, track))))
+}
+
+pub(crate) fn view_tracks <'a, T, U> (
+    w_mid:        u16,
+    w_side:       u16,
+    track_count:  &'a Arc<RwLock<String>>,
+    tracks_sizes: U,
+    selected:     Option<usize>,
+    editing:      bool,
+) -> impl Content<TuiOut> + use<'a, T, U> where
+    T: TracksSizes<'a>, U: Fn()->T + Send + Sync + 'a
+{
+    let callback = |t, track|view_track_header(t, track, selected == Some(t));
+    Tryptich::center(1)
+        .left(w_side, button_3("t", "track", track_count, editing))
+        .middle(w_mid, per_track(w_mid, tracks_sizes, callback))
+        .right(w_side, button_2("T", "add track", editing))
+}
+
+fn view_track_header <'a> (t: usize, track: &'a Track, active: bool) -> impl Content<TuiOut> + use<'a> {
+    let fg  = track.color.lightest.rgb;
+    let bg  = if active { track.color.light.rgb } else { track.color.base.rgb };
+    let bg2 = Reset;//if t > 0 { self.tracks()[t - 1].color.base.rgb } else { Reset };
+    wrap(bg, fg, Tui::bold(true, Fill::x(Align::nw(&track.name))))
+}
+
+#[cfg(test)] #[test] fn test_view_track () {
+    let mut output = TuiOut::default();
+    output.area[2] = 9;
+    output.area[3] = 9;
+
+    Content::render(&view_tracks(), &mut output);
+}