fix(studio): repeat audio FX reveal requests

Author: vanceingalls

packages/studio/src/components/editor/propertyPanelFxSection.test.tsx

@@ -162,6 +162,48 @@ afterEach(() => {
 });
 
 describe("FxSection chain", () => {
+  it("scrolls again when the same open parameter is revealed twice", () => {
+    const descriptor = Object.getOwnPropertyDescriptor(HTMLElement.prototype, "scrollIntoView");
+    const scrollIntoView = vi.fn();
+    Object.defineProperty(HTMLElement.prototype, "scrollIntoView", {
+      configurable: true,
+      value: scrollIntoView,
+    });
+    const chain: HfAudioFxChain = {
+      version: 1,
+      nodes: [
+        {
+          type: "lowpass",
+          id: "filter-1",
+          enabled: true,
+          params: defaultAudioFxParams("lowpass"),
+        },
+      ],
+    };
+    const renderFxSection = (revealNonce: number) => (
+      <FxSection
+        chain={chain}
+        onChainChange={vi.fn()}
+        onCarveChange={vi.fn()}
+        carve={null}
+        sourceOptions={[]}
+        revealTarget="fx.filter-1.frequency"
+        revealNonce={revealNonce}
+      />
+    );
+
+    try {
+      const { root } = renderInto(renderFxSection(1));
+      expect(scrollIntoView).toHaveBeenCalledTimes(1);
+
+      act(() => root.render(renderFxSection(2)));
+      expect(scrollIntoView).toHaveBeenCalledTimes(2);
+    } finally {
+      if (descriptor) Object.defineProperty(HTMLElement.prototype, "scrollIntoView", descriptor);
+      else Reflect.deleteProperty(HTMLElement.prototype, "scrollIntoView");
+    }
+  });
+
   it("says so when the track has no effects", () => {
     const { host } = mount();
     // "other", because the carve module is in the rack whenever a voice exists.

packages/studio/src/components/editor/propertyPanelFxSection.tsx

@@ -323,16 +323,12 @@ export function FxSection({
   }, [handBuilt, eqIds.length, showCarve]);
   const [openEq, setOpenEq] = useState<string | null>(null);
 
-  /**
-   * The parameter a reveal request asked for, held until its row is on screen.
-   *
-   * Set during render rather than in an effect, the way the Motion panel
-   * consumes its own focus request: the surface must open on the SAME commit
-   * the request lands on, or the scroll below runs against a row that has not
-   * mounted yet.
-   */
+  /** The reveal request held until its row is mounted and scrolled. */
   const [consumedRevealNonce, setConsumedRevealNonce] = useState<number | null>(null);
-  const pendingRevealRef = useRef<string | null>(null);
+  const [pendingReveal, setPendingReveal] = useState<{
+    nonce: number;
+    target: string;
+  } | null>(null);
   const rootRef = useRef<HTMLDivElement | null>(null);
   if (revealNonce != null && revealNonce !== consumedRevealNonce) {
     setConsumedRevealNonce(revealNonce);
@@ -351,27 +347,26 @@ export function FxSection({
           return next;
         });
       }
-      pendingRevealRef.current = revealTarget ?? null;
     }
+    setPendingReveal(where && revealTarget ? { nonce: revealNonce, target: revealTarget } : null);
   }
 
   /**
    * Scroll the revealed parameter into view once its row has actually mounted.
    *
-   * Keyed on the surfaces the block above opens, not on the request: the row
-   * appears on the commit AFTER they change, so scrolling in the same pass would
-   * miss it. Cleared once used, so a later re-render does not yank the panel
-   * back to a parameter the author has since scrolled away from.
+   * The request itself is a dependency so a second click on an already-open
+   * surface still scrolls. It is cleared once used, so a later unrelated
+   * re-render does not yank the panel back to an old parameter.
    */
   useEffect(() => {
-    const target = pendingRevealRef.current;
+    const target = pendingReveal?.target;
     if (target && scrollRevealedRowIntoView(rootRef.current, target, chain)) {
-      pendingRevealRef.current = null;
+      setPendingReveal(null);
     }
     // `chain` is deliberately not a dependency: it changes on every knob edit,
     // and re-running then would scroll the panel while the author is dragging.
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [openNode, openEq, carveOpen, collapsedRuns]);
+  }, [openNode, openEq, carveOpen, collapsedRuns, pendingReveal]);
 
   const addEq = useCallback(() => {
     clearAudition();

packages/studio/src/components/editor/useFxCarve.ts

@@ -37,11 +37,6 @@ import { carveLanes, measureCarve, mintCarveNodes } from "./useFxCarveNodes.js";
 import { spanOf } from "./propertyPanelAudioFxGroupUtils.js";
 import type { AudioTrackOption } from "./propertyPanelFxCarveModule.js";
 
-/**
- * Rate the carve source is decoded at. Analysis is self-consistent because it
- * reads the decoded buffer's own rate, so this only has to be a sane audio rate.
- */
-
 /**
  * Which carve setting actually moved, by comparing the two snapshots.
  *