Merge branch 'worktree-agent-a89309a856c8f4947' into integration

ui/dr-ui/src/lib.rs

@@ -583,8 +583,24 @@ pub(crate) fn sync_rows(
         // curve must be drawn whatever shape it is in.
         rows.set_vec(current);
         curve_moved = true;
+
+        // The curves the widget can switch between, named. They can only
+        // change with the operation set, which is what this branch means, so
+        // the walk that derives them is not on the parameter-event path.
+        let channels: Vec<slint::SharedString> = match session.borrow().as_ref() {
+            Some(s) => s.curve_channels().into_iter().map(Into::into).collect(),
+            None => Vec::new(),
+        };
+        window.set_curve_channels(slint::ModelRc::new(slint::VecModel::from(channels)));
     }
 
+    // Which curve is plotted, on every pass. Picking one that happens to be
+    // shaped like the last — two untouched curves are both the diagonal —
+    // moves no point, so this cannot ride on the resample below: the chips
+    // would go on highlighting the curve the user just navigated away from.
+    let channel = session.borrow().as_ref().map_or(0, |s| s.curve_channel());
+    window.set_curve_channel(channel);
+
     if !curve_moved {
         return;
     }
@@ -1804,6 +1820,24 @@ pub fn run(paths: Vec<PathBuf>) -> Result<()> {
             redraw(&w);
         });
     }
+    {
+        // Which of the curve's curves the plot is showing. **No redraw**, and
+        // that is the whole character of this control: it changes no
+        // parameter, so the photograph is already correct on screen and
+        // recomputing it would be a frame spent to produce the same pixels.
+        // For the same reason it records no history step — there is nothing
+        // to undo — and the sidecar never hears about it.
+        let weak = window.as_weak();
+        let session = session.clone();
+        let rows = rows.clone();
+        window.on_curve_channel_picked(move |index| {
+            let Some(w) = weak.upgrade() else { return };
+            if let Some(s) = session.borrow_mut().as_mut() {
+                s.set_curve_channel(index);
+            }
+            sync_rows(&w, &rows, &session);
+        });
+    }
 
     // ---- undo and redo (FR-DEV-5) ---------------------------------------
     //