remove some more string allocations from render loop

tek/src/lib.rs

@@ -534,18 +534,22 @@ impl Tek {
                 map_east(x1 as u16, w, border(Map::new(scenes, move|(_, scene, y1, y2), s| {
                     let last_color = last_color.clone();
                     let h = (1 + y2 - y1) as u16;
-                    let color = scene.color;
+                    let color    = scene.color;
-                    let (name, fg, bg) = if let Some(c) = &scene.clips[t] {
+                    let mut name = String::from("⏹ ");
-                        let c = c.read().unwrap();
+                    let mut fg   = Tui::g(64);
-                        (c.name.to_string(), c.color.lightest.rgb, c.color)
+                    let mut bg   = ItemPalette::G[32];
-                    } else {
+                    if let Some(clip) = &scene.clips[t] {
-                        ("⏹ ".to_string(), Tui::g(64), ItemPalette::G[32])
+                        let clip = clip.read().unwrap();
+                        name.clear();
+                        write!(&mut name, "{}", clip.name);
+                        fg = clip.color.lightest.rgb;
+                        bg = clip.color
                     };
                     let same_track = selected_track == Some(t+1);
                     let selected = same_track && Some(s+1) == selected_scene;
                     let neighbor = same_track && Some(s)   == selected_scene;
                     let active = editing && selected;
-                    let label = move||Tui::fg(fg, Push::x(1, Tui::bold(true, name.to_string())));
+                    let label = move||Tui::fg(fg, Push::x(1, Tui::bold(true, name.clone())));
                     let mid = if active { bg.light } else { bg.base };
                     let top = if neighbor { None } else { Some(last_color.read().unwrap().base.rgb) };
                     let mid = mid.rgb;
@@ -553,10 +557,10 @@ impl Tek {
                     *last_color.write().unwrap() = bg;
                     map_south(y1 as u16, h, Push::y(1, Fixed::y(h, Either::new(active,
                         Thunk::new(||Bsp::a(
-                            Fill::xy(Align::nw(button(" Tab ".into(), "".into()))),
+                            Fill::xy(Align::nw(button(" Tab ", ""))),
                             &self.editor)),
                         Thunk::new(move||Bsp::a(
-                            When::new(selected, Fill::y(Align::n(button(" Tab ".into(), "edit".into())))),
+                            When::new(selected, Fill::y(Align::n(button(" Tab ", "edit")))),
                             phat_sel_3(selected, label(), label(), top, mid, low)
                         )),
                     ))))
@@ -592,7 +596,7 @@ impl Tek {
     fn input_header <'a> (&'a self) -> ThunkBox<'a, TuiOut> {
         let fg = Tui::g(224);
         let bg = Tui::g(64);
-        (move||Bsp::s(Fill::x(Align::w(self.button(" I ".to_string(), format!(" midi ins ({})", self.midi_ins().len())))), self.midi_ins().get(0).map(|inp|Bsp::s(
+        (move||Bsp::s(Fill::x(Align::w(self.button(" I ", format!(" midi ins ({})", self.midi_ins().len())))), self.midi_ins().get(0).map(|inp|Bsp::s(
             Fill::x(Tui::bold(true, Tui::fg_bg(fg, bg, Align::w(inp.name.clone())))),
             inp.connect.get(0).map(|connect|Fill::x(Align::w(Tui::bold(false,
                 Tui::fg_bg(fg, bg, connect.info()))))),
@@ -601,17 +605,17 @@ impl Tek {
     fn output_header <'a> (&'a self) -> ThunkBox<'a, TuiOut> {
         let fg = Tui::g(224);
         let bg = Tui::g(64);
-        (move||Bsp::s(Fill::x(Align::w(self.button(" O ".to_string(), format!(" midi outs ({}) ", self.midi_outs().len())))), self.midi_outs().get(0).map(|out|Bsp::s(
+        (move||Bsp::s(Fill::x(Align::w(self.button(" O ", format!(" midi outs ({}) ", self.midi_outs().len())))), self.midi_outs().get(0).map(|out|Bsp::s(
             Fill::x(Tui::bold(true, Tui::fg_bg(fg, bg, Align::w(out.name.clone())))),
             out.connect.get(0).map(|connect|Fill::x(Align::w(Tui::bold(false,
                 Tui::fg_bg(fg, bg, connect.info()))))),
         ))).boxed()).into()
     }
     fn track_header <'a> (&'a self) -> ThunkBox<'a, TuiOut> {
-        let add_scene = ||self.button(" C-a ".to_string(), format!(" add scene ({}/{})",
+        let add_scene = ||self.button(" C-a ", format!(" add scene ({}/{})",
             self.selected.scene().unwrap_or(0),
             self.scenes().len()));
-        let add_track = ||self.button(" C-t ".to_string(), format!(" add track ({}/{})",
+        let add_track = ||self.button(" C-t ", format!(" add track ({}/{})",
             self.selected.track().unwrap_or(0),
             self.tracks().len()));
         (move||Tui::bg(Tui::g(32), Bsp::s(
@@ -619,7 +623,9 @@ impl Tek {
             Fill::x(Align::w(add_track())),
         )).boxed()).into()
     }
-    fn button (&self, key: String, label: String) -> impl Content<TuiOut> {
+    fn button <'a> (
+        &'a self, key: impl Content<TuiOut> + 'a, label: impl Content<TuiOut> + 'a
+    ) -> impl Content<TuiOut> + 'a {
         let compact = !self.is_editing();
         Tui::bold(true, Bsp::e(
             Margin::x(1, Tui::fg_bg(Tui::g(0), Tui::orange(), key)),
@@ -1269,7 +1275,7 @@ audio!(|self: Tek, client, scope|{
     self.perf.update(t0, scope);
     Control::Continue
 });
-fn button (key: String, label: String) -> impl Content<TuiOut> {
+fn button (key: &'static str, label: &'static str) -> impl Content<TuiOut> + 'static {
     Tui::bold(true, Bsp::e(
         Margin::x(1, Tui::fg_bg(Tui::g(0),   Tui::orange(), key)),
         Margin::x(1, Tui::fg_bg(Tui::g(255), Tui::g(96),    label)),