use compound web sticky patch

- Compound 10.3.0 bounds a menu by the space it has and scrolls what
  doesn't fit, within a boundary the app passes. The menus pass the call
  area, 16px in from its sides, rather than measuring its width.
- The 296px width is the menu's own style. Compound gives that style only
  to the dropdown, so menuIsDrawer, which copied its phone rule, goes.
- Compound draws the menu's frame over its content, so nothing that
  scrolls can hide it in Safari: the list, headings and meter no longer
  keep a border width clear of it, and the checks that they did go.
- The device list is Compound's scroll area, so it fades out at the
  foot with Compound's chevron while there is more below.
- The microphone menu's meter sticks at that foot, with rows scrolling
  under it as before, so the list has no fade above it: Compound's is a
  mask fixed to the list's edge, while a bounce at the top carries the
  meter with the rows. The band under the meter is filled, or rows would
  show there. The edge fades from where the chevron starts, so a bounce
  fades the meter out before it reaches the chevron. A row reached by
  keyboard stays above the meter.
- The list's height is still its share of the call.
- The component harness leaves the host's stylesheets unscoped, Compound's
  among them, as a host does: scoped, they never reached the menu, which is
  portalled out of Element Call's root.
- Its specs check only Element Call's own document styles on the host
  page, and find the device list within Compound's scroll area.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

component/build/scopeStylesToRoot.test.ts

@@ -109,4 +109,12 @@ describe("scopeStylesToRoot", () => {
       ".a .b_abc12:hover { border: 0 }",
     );
   });
+
+  it("leaves an excluded stylesheet as it is", async () => {
+    const css = "body { margin: 0 } .menu { color: red }";
+    const result = await postcss([
+      scopeStylesToRoot({ exclude: [/host\.css$/] }),
+    ]).process(css, { from: "/app/host.css" });
+    expect(result.css).toBe(css);
+  });
 });

component/build/scopeStylesToRoot.ts

@@ -60,12 +60,18 @@ const IS_ROOT = `:where(${ROOT_SELECTOR})`;
  * tokens, the component styles, the fonts — is not in this build at all: the
  * host supplies it, unscoped, along with its copy of Compound.
  */
-export function scopeStylesToRoot(): Plugin {
+interface Options {
+  /** Stylesheets left as they are: a host's own, which it doesn't scope. */
+  exclude?: RegExp[];
+}
+
+export function scopeStylesToRoot({ exclude = [] }: Options = {}): Plugin {
   return {
     postcssPlugin: "element-call-scope-styles-to-root",
     Once(root) {
-      const isModule =
-        root.source?.input.file?.endsWith(".module.css") ?? false;
+      const file = root.source?.input.file ?? "";
+      if (exclude.some((pattern) => pattern.test(file))) return;
+      const isModule = file.endsWith(".module.css");
       root.walkRules((rule) => {
         if (isRelative(rule)) return;
         rule.selector = (isModule ? scopeBare : scopeAll).processSync(

docker-compose-playwright.yml

@@ -19,7 +19,7 @@ services:
       - ./backend/playwright_homeserver-othersite.yaml:/data/cfg/homeserver.yaml:Z
   element-web:
     # Pin to a SHA so that upstream cannot break our tests. Renovate handles regular updates.
-    image: ghcr.io/element-hq/element-web:develop@sha256:b2a5a30afb4f583a7560448b005d8332bee29672f15826e4a995b393058f0291
+    image: ghcr.io/element-hq/element-web:develop@sha256:79e47d8d5a93848403cb83042a405d8ed233a7727c499fa53b4b39a80f090be4
   element-web-1:
     # Pin to a SHA so that upstream cannot break our tests. Renovate handles regular updates.
-    image: ghcr.io/element-hq/element-web:develop@sha256:b2a5a30afb4f583a7560448b005d8332bee29672f15826e4a995b393058f0291
+    image: ghcr.io/element-hq/element-web:develop@sha256:79e47d8d5a93848403cb83042a405d8ed233a7727c499fa53b4b39a80f090be4

package.json

@@ -88,7 +88,7 @@
     "@typescript-eslint/utils": "^8.61.0",
     "@use-gesture/react": "^10.2.11",
     "@vector-im/compound-design-tokens": "^11.0.0",
-    "@vector-im/compound-web": "^10.4.0",
+    "@vector-im/compound-web": "github:element-hq/compound-web#c0578aab8ea2f2016f9e6a3dbd2d95f2737b635c",
     "@vitejs/plugin-react": "^6.0.2",
     "@vitest/browser-playwright": "^4.1.5",
     "@vitest/coverage-v8": "^4.0.18",

playwright/component/component-call.spec.ts

@@ -125,25 +125,24 @@ test("leaves the host's own page unstyled", async ({ page }) => {
     timeout: 60_000,
   });
 
-  // Element Call's stylesheet is written for a page of its own: normalize.css
-  // gives `html` a line height, Compound gives `body` its font and feature
-  // settings, and the design tokens live on `:root`. None of that may reach the
-  // host's document — the harness sets none of these itself, so anything other
-  // than the browser's defaults here came from us.
+  // Element Call's page-wide CSS (normalize.css and the tokens in base.css)
+  // should not reach the host's page. Compound CSS that gets loaded to EW (host)
+  // on the other hand should impact the host. So probe with styles only Element Call sets:
+  // - A fresh <sub> keeps the browser's `vertical-align: sub` unless
+  //   normalize.css leaked; it turns that into `baseline`.
+  // - `--font-scale` is Element Call's own token, so `:root` must not have it.
   const host = await page.evaluate(() => {
-    const html = getComputedStyle(document.documentElement);
-    const body = getComputedStyle(document.body);
+    const sub = document.body.appendChild(document.createElement("sub"));
+    const verticalAlign = getComputedStyle(sub).verticalAlign;
+    sub.remove();
     return {
-      lineHeight: html.lineHeight,
-      fontFeatureSettings: body.fontFeatureSettings,
-      token: html.getPropertyValue("--cpd-color-text-primary"),
+      verticalAlign,
+      token: getComputedStyle(document.documentElement).getPropertyValue(
+        "--font-scale",
+      ),
     };
   });
-  expect(host).toEqual({
-    lineHeight: "normal",
-    fontFeatureSettings: "normal",
-    token: "",
-  });
+  expect(host).toEqual({ verticalAlign: "sub", token: "" });
 
   // While inside the container, the same rules do apply
   const root = panes.first().locator("[data-element-call-root]");

playwright/widget/test-helpers.ts

@@ -159,7 +159,7 @@ export class TestHelpers {
   public static async dismissStartupToasts(page: Page): Promise<void> {
     const expectedToasts = [
       { title: "Failed to load service worker", button: "OK" },
-      { title: "Back up your chats", button: "Dismiss" },
+      { title: "Back up your chats", button: "Not now" },
       { title: "Turn on key storage", button: "Dismiss" },
       { title: "Element does not support this browser", button: "Dismiss" },
     ];
@@ -178,7 +178,11 @@ export class TestHelpers {
         );
 
         if (toastConfig) {
-          await toast.getByRole("button", { name: toastConfig.button }).click();
+          // Bounded so that a renamed button leaves the toast in place and the
+          // next step reports it, instead of hanging until the test timeout.
+          await toast
+            .getByRole("button", { name: toastConfig.button })
+            .click({ timeout: 5000 });
         } else {
           // Unknown toast. We don't want to act on unknown toasts
           break;

pnpm-lock.yaml

@@ -134,8 +134,8 @@ importers:
         specifier: ^11.0.0
         version: 11.3.1(@types/react@19.2.18)(react@19.2.8)
       '@vector-im/compound-web':
-        specifier: ^10.4.0
-        version: 10.4.0(@fontsource/inconsolata@5.3.0)(@fontsource/inter@5.3.0)(@types/react-dom@19.2.5(@types/react@19.2.18))(@types/react@19.2.18)(@vector-im/compound-design-tokens@11.3.1(@types/react@19.2.18)(react@19.2.8))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
+        specifier: github:element-hq/compound-web#c0578aab8ea2f2016f9e6a3dbd2d95f2737b635c
+        version: https://codeload.github.com/element-hq/compound-web/tar.gz/c0578aab8ea2f2016f9e6a3dbd2d95f2737b635c(@fontsource/inconsolata@5.3.0)(@fontsource/inter@5.3.0)(@types/react-dom@19.2.5(@types/react@19.2.18))(@types/react@19.2.18)(@vector-im/compound-design-tokens@11.3.1(@types/react@19.2.18)(react@19.2.8))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
       '@vitejs/plugin-react':
         specifier: ^6.0.2
         version: 6.1.1(@rolldown/plugin-babel@0.2.3(@babel/core@7.29.7(supports-color@7.2.0))(@babel/runtime@8.0.0)(rolldown@1.2.15)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0)))(babel-plugin-react-compiler@1.0.0)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0))
@@ -408,10 +408,6 @@ packages:
     resolution: {integrity: sha512-B3lYAs2nkKskbgQ1nfy8Ma9ao9Q1rntTAQHrzzyDuj+TSO+X3le6PfWwqDvodsb+OumE10eMFfuMCTQSQ5iuIQ==}
     engines: {node: '>=6.9.0'}
 
-  '@babel/traverse@7.29.8':
-    resolution: {integrity: sha512-I5z7H3bf/41ktsNVLtpN0wAa336HkqIHQ5BuPLEhTkt1jVSyZpeNKIzTgEWmlxjdg81R0IgUCcaE+Ok3NvrfZg==}
-    engines: {node: '>=6.9.0'}
-
   '@babel/types@7.29.11':
     resolution: {integrity: sha512-WCsemW40Cpc6gouC1SrY6PBaZ+oLRlEVY9XBvZBI7il/HyUrb2nJ505wE1MHEFyDZNnrWDEuy4jL50WVHfTTSQ==}
     engines: {node: '>=6.9.0'}
@@ -3314,8 +3310,9 @@ packages:
       react:
         optional: true
 
-  '@vector-im/compound-web@10.4.0':
-    resolution: {integrity: sha512-Tt5hsNK7ulhGdRuy9lzSm5C+T8M/4O4kLDFLkaU+Hi1kVWj6tj/5awW+U+GvtpWRh5llbHN2HRCh79+gQhek+A==}
+  '@vector-im/compound-web@https://codeload.github.com/element-hq/compound-web/tar.gz/c0578aab8ea2f2016f9e6a3dbd2d95f2737b635c':
+    resolution: {gitHosted: true, integrity: sha512-I2CWgw36c/P1EZJYuc8+rOaALkSnl4UDtANua2/ICyTiAGRiMgbJw49/gUJV1ElMqqAR/bK0o4bcqNVg7wA+vA==, tarball: https://codeload.github.com/element-hq/compound-web/tar.gz/c0578aab8ea2f2016f9e6a3dbd2d95f2737b635c}
+    version: 10.4.0
     peerDependencies:
       '@fontsource/inconsolata': ^5
       '@fontsource/inter': ^5
@@ -3421,11 +3418,6 @@ packages:
     engines: {node: '>=0.4.0'}
     hasBin: true
 
-  acorn@8.18.0:
-    resolution: {integrity: sha512-lGq+9yr1/GuAWaVYIHRjvvySG5/4VfKIvC8EWxStPdcDh/Ka7FG3twP6v4d5BkravUilhIAsG4Qj83t02LWUPQ==}
-    engines: {node: '>=0.4.0'}
-    hasBin: true
-
   acorn@8.19.0:
     resolution: {integrity: sha512-oJlA3XiRm7Cyk6qFD2Jn8ak9B7jSy0qy00ADO3+8dpT0LSjFihQYv4C02LFCSYJV3Q37xYwwRy5m+IpIiUzqWw==}
     engines: {node: '>=0.4.0'}
@@ -6357,10 +6349,10 @@ snapshots:
       '@babel/helper-compilation-targets': 7.29.7
       '@babel/helper-module-transforms': 7.29.7(@babel/core@7.29.7(supports-color@7.2.0))(supports-color@7.2.0)
       '@babel/helpers': 7.29.7
-      '@babel/parser': 7.29.8
+      '@babel/parser': 7.29.11
       '@babel/template': 7.29.7
-      '@babel/traverse': 7.29.8(supports-color@7.2.0)
-      '@babel/types': 7.29.8
+      '@babel/traverse': 7.29.10(supports-color@7.2.0)
+      '@babel/types': 7.29.11
       '@jridgewell/remapping': 2.3.5
       convert-source-map: 2.0.0
       debug: 4.4.3(supports-color@7.2.0)
@@ -6372,8 +6364,8 @@ snapshots:
 
   '@babel/generator@7.29.8':
     dependencies:
-      '@babel/parser': 7.29.8
-      '@babel/types': 7.29.8
+      '@babel/parser': 7.29.11
+      '@babel/types': 7.29.11
       '@jridgewell/gen-mapping': 0.3.13
       '@jridgewell/trace-mapping': 0.3.31
       jsesc: 3.1.0
@@ -6390,8 +6382,8 @@ snapshots:
 
   '@babel/helper-module-imports@7.29.7(supports-color@7.2.0)':
     dependencies:
-      '@babel/traverse': 7.29.8(supports-color@7.2.0)
-      '@babel/types': 7.29.8
+      '@babel/traverse': 7.29.10(supports-color@7.2.0)
+      '@babel/types': 7.29.11
     transitivePeerDependencies:
       - supports-color
 
@@ -6400,7 +6392,7 @@ snapshots:
       '@babel/core': 7.29.7(supports-color@7.2.0)
       '@babel/helper-module-imports': 7.29.7(supports-color@7.2.0)
       '@babel/helper-validator-identifier': 7.29.7
-      '@babel/traverse': 7.29.8(supports-color@7.2.0)
+      '@babel/traverse': 7.29.10(supports-color@7.2.0)
     transitivePeerDependencies:
       - supports-color
 
@@ -6417,7 +6409,7 @@ snapshots:
   '@babel/helpers@7.29.7':
     dependencies:
       '@babel/template': 7.29.7
-      '@babel/types': 7.29.8
+      '@babel/types': 7.29.11
 
   '@babel/parser@7.29.11':
     dependencies:
@@ -6438,8 +6430,8 @@ snapshots:
   '@babel/template@7.29.7':
     dependencies:
       '@babel/code-frame': 7.29.7
-      '@babel/parser': 7.29.8
-      '@babel/types': 7.29.8
+      '@babel/parser': 7.29.11
+      '@babel/types': 7.29.11
 
   '@babel/traverse@7.29.10(supports-color@7.2.0)':
     dependencies:
@@ -6448,19 +6440,7 @@ snapshots:
       '@babel/helper-globals': 7.29.7
       '@babel/parser': 7.29.11
       '@babel/template': 7.29.7
-      '@babel/types': 7.29.8
-      debug: 4.4.3(supports-color@7.2.0)
-    transitivePeerDependencies:
-      - supports-color
-
-  '@babel/traverse@7.29.8(supports-color@7.2.0)':
-    dependencies:
-      '@babel/code-frame': 7.29.7
-      '@babel/generator': 7.29.8
-      '@babel/helper-globals': 7.29.7
-      '@babel/parser': 7.29.8
-      '@babel/template': 7.29.7
-      '@babel/types': 7.29.8
+      '@babel/types': 7.29.11
       debug: 4.4.3(supports-color@7.2.0)
     transitivePeerDependencies:
       - supports-color
@@ -8903,7 +8883,7 @@ snapshots:
       '@types/react': 19.2.18
       react: 19.2.8
 
-  '@vector-im/compound-web@10.4.0(@fontsource/inconsolata@5.3.0)(@fontsource/inter@5.3.0)(@types/react-dom@19.2.5(@types/react@19.2.18))(@types/react@19.2.18)(@vector-im/compound-design-tokens@11.3.1(@types/react@19.2.18)(react@19.2.8))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)':
+  '@vector-im/compound-web@https://codeload.github.com/element-hq/compound-web/tar.gz/c0578aab8ea2f2016f9e6a3dbd2d95f2737b635c(@fontsource/inconsolata@5.3.0)(@fontsource/inter@5.3.0)(@types/react-dom@19.2.5(@types/react@19.2.18))(@types/react@19.2.18)(@vector-im/compound-design-tokens@11.3.1(@types/react@19.2.18)(react@19.2.8))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)':
     dependencies:
       '@floating-ui/react': 0.27.20(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
       '@floating-ui/react-dom': 2.1.9(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
@@ -9055,14 +9035,12 @@ snapshots:
 
   '@webcontainer/env@1.1.1': {}
 
-  acorn-jsx@5.3.2(acorn@8.18.0):
+  acorn-jsx@5.3.2(acorn@8.19.0):
     dependencies:
-      acorn: 8.18.0
+      acorn: 8.19.0
 
   acorn@8.16.0: {}
 
-  acorn@8.18.0: {}
-
   acorn@8.19.0: {}
 
   agent-base@6.0.2(supports-color@7.2.0):
@@ -9733,8 +9711,8 @@ snapshots:
 
   espree@9.6.1:
     dependencies:
-      acorn: 8.18.0
-      acorn-jsx: 5.3.2(acorn@8.18.0)
+      acorn: 8.19.0
+      acorn-jsx: 5.3.2(acorn@8.19.0)
       eslint-visitor-keys: 3.4.3
 
   esprima@4.0.1: {}
@@ -11701,7 +11679,7 @@ snapshots:
   terser@5.46.1:
     dependencies:
       '@jridgewell/source-map': 0.3.11
-      acorn: 8.18.0
+      acorn: 8.19.0
       commander: 2.20.3
       source-map-support: 0.5.21
 

pnpm-workspace.yaml

@@ -14,6 +14,7 @@ allowBuilds:
   "core-js": true
   "esbuild": true
   "matrix-js-sdk@git+https://github.com/matrix-org/matrix-js-sdk.git": true
+  "@vector-im/compound-web@git+https://github.com/element-hq/compound-web.git": true
   "protobufjs": true
 overrides:
   # We need compatible versions of RxJS in our dependencies and LiveKit's dependencies, but

src/AppBar.module.css

@@ -7,6 +7,7 @@
   padding-top: env(safe-area-inset-top);
   opacity: 1;
   transition: opacity 0.15s;
+  text-align: center;
 }
 
 /* Pseudo-element for the gradient background */
@@ -52,7 +53,7 @@
     ". . ."
     "primaryButton title secondaryButton"
     ". . .";
-  place-items: center;
+  place-items: center stretch;
   column-gap: var(--cpd-space-2x);
 }
 

src/components/MediaMuteAndSwitchButton.module.css

@@ -36,20 +36,15 @@ Please see LICENSE in the repository root for full details.
   }
 }
 
+/* The width design sets: a long device name wraps. */
 .menu {
-  display: flex;
-  flex-direction: column;
+  inline-size: 296px;
 }
 
-/* Only the device lists scroll, bounded by the measured call area: the menu is
-   portalled out of the root, so CSS can't size it against the call. */
+/* Its share of the measured call area: the menu is portalled out of the root,
+   so CSS can't size it against the call. */
 .deviceList {
-  overflow-y: auto;
-  min-block-size: 0;
   max-block-size: var(--device-list-max-height);
-  /* Keeps a row reached by keyboard clear of the sticky heading and meter. */
-  scroll-padding-block: var(--device-list-scroll-padding-start, 0)
-    var(--device-list-scroll-padding-end, 0);
 }
 
 /* Compound's heading rule heads each section; the design adds space below it. */
@@ -62,25 +57,6 @@ Please see LICENSE in the repository root for full details.
   margin-block-start: var(--cpd-space-7x);
 }
 
-/* Sticky within its own section. Opaque and inset a border width so it doesn't
-   paint over the menu's outline. */
-.sectionHeading {
-  position: sticky;
-  inset-block-start: 0;
-  background: var(--cpd-color-bg-canvas-default);
-  margin-inline: var(--cpd-border-width-1);
-  margin-block-start: var(--cpd-border-width-1);
-}
-
-/* Sticky at the foot of the microphone section; opaque and inset as above. */
-.stickyMeter {
-  position: sticky;
-  inset-block-end: 0;
-  background: var(--cpd-color-bg-canvas-default);
-  margin-inline: var(--cpd-border-width-1);
-  margin-block-end: var(--cpd-border-width-1);
-}
-
 /* Radix focuses whatever the pointer is over, so the browser's ring would
    follow the mouse. Replaced by one shown only for keyboard focus. */
 .menu [role^="menuitem"]:focus,

src/components/MediaMuteAndSwitchButton.stories.tsx

@@ -65,8 +65,10 @@ const WithACallArea: FC<{ children: ReactNode }> = ({ children }) => {
     <div
       ref={setCallArea}
       style={{
-        // A call's size: anything smaller makes a short device list scroll.
+        // A call's size: anything smaller makes a short device list scroll, and
+        // a narrower one narrows the menu.
         blockSize: 720,
+        inlineSize: 1024,
         display: "flex",
         alignItems: "flex-end",
         justifyContent: "center",
@@ -97,6 +99,10 @@ const meta = {
 export default meta;
 type Story = StoryObj<typeof meta>;
 
+// By place: Compound's section heading is aria-hidden, as its group carries
+// the name.
+const SECTION_HEADING = "[role='group'] > [aria-hidden]";
+
 export const Default: Story = {
   args: {
     iconsAndLabels: "audio",
@@ -219,9 +225,8 @@ export const SpeakerAndMicrophoneSections: Story = {
     await expect(
       document.body.querySelectorAll("[role='separator']"),
     ).toHaveLength(0);
-    const headings = document.body.querySelectorAll<HTMLElement>(
-      `.${styles.sectionHeading}`,
-    );
+    const headings =
+      document.body.querySelectorAll<HTMLElement>(SECTION_HEADING);
     await expect(headings).toHaveLength(2);
     const frame = menu.getBoundingClientRect();
     for (const heading of headings) {
@@ -256,6 +261,37 @@ export const SpeakerAndMicrophoneSections: Story = {
   },
 };
 
+/** A long name wraps rather than widening the menu, which design sets. */
+export const LongDeviceNameWraps: Story = {
+  args: {
+    ...SpeakerAndMicrophoneSections.args,
+    outputOptions: [
+      {
+        label: {
+          type: "name",
+          name: "Logitech BRIO 4K Ultra HD Pro Business Webcam Speakers (046d:085e)",
+        },
+        id: "long",
+      },
+      { label: { type: "name", name: "Headset" }, id: "spk2" },
+    ],
+    selectedOutputOption: "long",
+  },
+  play: async ({ canvasElement }) => {
+    const canvas = within(canvasElement);
+    await userEvent.click(canvas.getByRole("button", { name: "Microphone" }));
+    const body = within(document.body);
+    const long = await body.findByRole("menuitemradio", { name: /Logitech/ });
+    const short = await body.findByRole("menuitemradio", { name: "Headset" });
+
+    const menu = document.body.querySelector("[role='menu']")!;
+    await expect(Math.round(menu.getBoundingClientRect().width)).toBe(296);
+    await expect(long.getBoundingClientRect().height).toBeGreaterThan(
+      short.getBoundingClientRect().height,
+    );
+  },
+};
+
 export const OutputCannotBeChosen: Story = {
   args: {
     ...Default.args,
@@ -402,14 +438,14 @@ export const ManyDevices: Story = {
     await userEvent.click(canvas.getByRole("button", { name: "Microphone" }));
     const menu = within(document.body);
 
-    // The sticky wrapper rather than the meter: without a fake microphone (as on
+    // The meter's box rather than its level: without a fake microphone (as on
     // WebKit) the meter shows a message instead of a level.
     const list = document.body.querySelector<HTMLElement>(
       `.${styles.deviceList}`,
     )!;
     const sticky = await waitFor(() => {
       const element = document.body.querySelector<HTMLElement>(
-        `.${styles.stickyMeter}`,
+        `.${meterStyles.meter}`,
       );
       if (element === null) throw new Error("the meter has not rendered yet");
       return element;
@@ -436,10 +472,6 @@ export const ManyDevices: Story = {
       .getBoundingClientRect();
     await expect(frame.top).toBeGreaterThanOrEqual(0);
     await expect(frame.bottom).toBeLessThanOrEqual(window.innerHeight + 1);
-
-    // The meter is the menu's one opaque part, so it must stay inside the frame.
-    await expect(pinned.left).toBeGreaterThan(frame.left);
-    await expect(pinned.right).toBeLessThan(frame.right);
   },
 };
 
@@ -536,7 +568,7 @@ export const KeyboardReachesEveryDevice: Story = {
 
     const meter = await waitFor(() => {
       const element = document.body.querySelector<HTMLElement>(
-        `.${styles.stickyMeter}`,
+        `.${meterStyles.meter}`,
       );
       if (element === null) throw new Error("the meter has not rendered yet");
       return element;
@@ -545,9 +577,7 @@ export const KeyboardReachesEveryDevice: Story = {
     // Drawn over the list: the sticky headings and the meter.
     const overlays = [
       meter,
-      ...document.body.querySelectorAll<HTMLElement>(
-        `.${styles.sectionHeading}`,
-      ),
+      ...document.body.querySelectorAll<HTMLElement>(SECTION_HEADING),
     ];
     const items = within(document.body).getAllByRole("menuitemradio");
 
@@ -591,10 +621,7 @@ export const HeadingsStayWhileScrolling: Story = {
       `.${styles.deviceList}`,
     )!;
     const group = await menu.findByRole("group", { name: "Microphone" });
-    // By class: the heading is aria-hidden, and its group carries the name.
-    const heading = group.querySelector<HTMLElement>(
-      `.${styles.sectionHeading}`,
-    )!;
+    const heading = group.querySelector<HTMLElement>(":scope > [aria-hidden]")!;
 
     // Far enough that the heading is only on screen if it is stuck there.
     list.scrollTop +=
@@ -607,13 +634,6 @@ export const HeadingsStayWhileScrolling: Story = {
     await expect(heading.getBoundingClientRect().bottom).toBeGreaterThan(
       scrollport.top,
     );
-    // Clear of the menu's frame.
-    const frame = document.body
-      .querySelector("[role='menu']")!
-      .getBoundingClientRect();
-    await expect(heading.getBoundingClientRect().left).toBeGreaterThan(
-      frame.left,
-    );
   },
 };
 

src/components/MediaMuteAndSwitchButton.tsx

@@ -17,7 +17,8 @@ import {
   Button,
   Menu,
   MenuItem,
-  MenuTitle,
+  MenuScrollArea,
+  MenuScrollSection,
   RadioInput,
   ToggleMenuItem,
 } from "@vector-im/compound-web";
@@ -84,6 +85,9 @@ const LIST_SHARE_OF_CALL = 0.6;
 /** Smallest device list height in px, so a short call still shows more than one device. */
 const MIN_LIST_HEIGHT = 160;
 
+/** Space kept between the menu and the call area's sides. */
+const MENU_MARGIN = 16;
+
 export const MediaMuteAndSwitchButton: FC<MediaMuteAndSwitchButtonProps> = ({
   enabled,
   busy,
@@ -157,18 +161,18 @@ export const MediaMuteAndSwitchButton: FC<MediaMuteAndSwitchButtonProps> = ({
     return (): void => subscription.unsubscribe();
   }, [menuOpen, rootElement]);
 
-  // Kept clear at the list's foot, so a row reached by keyboard isn't under
-  // the meter.
-  const [meterHeight, meter] = useMeasuredHeight();
-
-  // Likewise at its head, for the sticky headings.
-  const [headingHeight, heading] = useMeasuredHeight();
-
   useEffect(() => {
     if (menuOpen) devices.requestDeviceNames(); // No-op after the first call
   }, [menuOpen, devices]);
 
-  const MuteButton = iconsAndLabels === "audio" ? MicButton : VideoButton;
+  const audioMeter = iconsAndLabels === "audio" && (
+    <LiveMicrophoneLevelMeter
+      deviceId={selectedOption}
+      // Only while open, so the microphone isn't held all call.
+      active={menuOpen}
+    />
+  );
+  const MuteButton = audioMeter ? MicButton : VideoButton;
   const button = (
     <MuteButton
       enabled={enabled ?? false}
@@ -179,9 +183,7 @@ export const MediaMuteAndSwitchButton: FC<MediaMuteAndSwitchButtonProps> = ({
         e.stopPropagation();
       }}
       disabled={isBusy || onMuteClick === undefined}
-      data-testid={
-        iconsAndLabels === "audio" ? "incall_mute" : "incall_videomute"
-      }
+      data-testid={audioMeter ? "incall_mute" : "incall_videomute"}
     />
   );
 
@@ -326,6 +328,8 @@ export const MediaMuteAndSwitchButton: FC<MediaMuteAndSwitchButtonProps> = ({
         open={menuOpen}
         onOpenChange={onOpenChange}
         side="top"
+        collisionBoundary={rootElement}
+        collisionPadding={MENU_MARGIN}
         trigger={
           <Button
             iconOnly
@@ -340,66 +344,41 @@ export const MediaMuteAndSwitchButton: FC<MediaMuteAndSwitchButtonProps> = ({
           />
         }
       >
-        <div
+        <MenuScrollArea
           ref={trackFocusSource}
-          // Keeps the items the menu's own children for assistive tech.
-          role="none"
           className={styles.deviceList}
           data-testid="device-list"
           style={
             {
               "--device-list-max-height":
                 listMaxHeight === undefined ? undefined : `${listMaxHeight}px`,
-              "--device-list-scroll-padding-end":
-                meterHeight === undefined ? undefined : `${meterHeight}px`,
-              "--device-list-scroll-padding-start":
-                headingHeight === undefined ? undefined : `${headingHeight}px`,
             } as CSSProperties
           }
         >
-          {iconsAndLabels === "audio" && speakerOptions && (
-            <>
-              {/* A menu may only contain items, separators and groups, so each
-                  heading is a hidden part of a named group. */}
-              <div role="group" aria-label={t("settings.devices.speaker")}>
-                <div aria-hidden className={styles.sectionHeading}>
-                  <MenuTitle title={t("settings.devices.speaker")} />
-                </div>
-                {deviceItems(
-                  "output",
-                  speakerOptions,
-                  selectedSpeaker,
-                  onSelectOutput,
-                  (n) => t("settings.devices.speaker_numbered", { n }),
-                )}
-              </div>
-            </>
-          )}
-          <div role="group" aria-label={optionsButtonLabel}>
-            <div ref={heading} aria-hidden className={styles.sectionHeading}>
-              <MenuTitle title={optionsButtonLabel} />
-            </div>
-            {/* Apart from the heading, so the sticky meter can't ride over it. */}
-            <div role="none">
+          {audioMeter && speakerOptions && (
+            <MenuScrollSection title={t("settings.devices.speaker")}>
               {deviceItems(
-                "input",
-                options,
-                selectedOption,
-                onSelect,
-                numberedLabel,
+                "output",
+                speakerOptions,
+                selectedSpeaker,
+                onSelectOutput,
+                (n) => t("settings.devices.speaker_numbered", { n }),
               )}
-              {iconsAndLabels === "audio" && (
-                <LiveMicrophoneLevelMeter
-                  ref={meter}
-                  deviceId={selectedOption}
-                  // Only while open, so the microphone isn't held all call.
-                  active={menuOpen}
-                  className={styles.stickyMeter}
-                />
-              )}
-            </div>
-          </div>
-        </div>
+            </MenuScrollSection>
+          )}
+          <MenuScrollSection
+            title={optionsButtonLabel}
+            stickyBottomItem={audioMeter}
+          >
+            {deviceItems(
+              "input",
+              options,
+              selectedOption,
+              onSelect,
+              numberedLabel,
+            )}
+          </MenuScrollSection>
+        </MenuScrollArea>
         {toggles.length > 0 && <hr />}
         {toggles.map((toggle) => (
           <ToggleMenuItem
@@ -416,25 +395,3 @@ export const MediaMuteAndSwitchButton: FC<MediaMuteAndSwitchButtonProps> = ({
     </div>
   );
 };
-
-/** Follows an element's height. */
-function useMeasuredHeight(): [
-  number | undefined,
-  (element: HTMLElement | null) => (() => void) | undefined,
-] {
-  const [height, setHeight] = useState<number>();
-  const ref = useCallback(
-    (element: HTMLElement | null): (() => void) | undefined => {
-      if (element === null) return;
-      const subscription = observeElementSize$(element)
-        .pipe(
-          map((size) => size.height),
-          distinctUntilChanged(),
-        )
-        .subscribe(setHeight);
-      return (): void => subscription.unsubscribe();
-    },
-    [],
-  );
-  return [height, ref];
-}

src/components/MicrophoneLevelMeter.module.css

@@ -16,10 +16,10 @@ Please see LICENSE in the repository root for full details.
   align-items: center;
   gap: var(--cpd-space-3x);
   padding-block: var(--cpd-space-2x);
-  /* Centres the icon on the radio column: less the row's inset border and half
-     the icon's extra width. Checked in the MeterAlignsWithTheDeviceRows story. */
+  /* Centres the icon on the radio column: less half the icon's extra width.
+     Checked in the MeterAlignsWithTheDeviceRows story. */
   padding-inline-start: calc(
-    var(--cpd-space-4x) - var(--cpd-border-width-1) -
+    var(--cpd-space-4x) -
       (var(--meter-icon-size) - var(--device-control-size)) / 2
   );
   padding-inline-end: calc(var(--cpd-space-4x) * 2 + var(--cpd-space-2x));

src/components/MicrophoneLevelMeter.tsx

@@ -5,17 +5,9 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */
 
-import {
-  useCallback,
-  useLayoutEffect,
-  useRef,
-  useState,
-  type FC,
-  type Ref,
-} from "react";
+import { useCallback, useLayoutEffect, useRef, useState, type FC } from "react";
 import { Text } from "@vector-im/compound-web";
 import { MicOnIcon } from "@vector-im/compound-design-tokens/assets/web/icons";
-import classNames from "classnames";
 import { useTranslation } from "react-i18next";
 
 import { distinctUntilChanged, map } from "rxjs";
@@ -30,8 +22,6 @@ export interface LiveMicrophoneLevelMeterProps {
   deviceId: string | undefined;
   /** Whether to hold a capture at all. */
   active: boolean;
-  className?: string;
-  ref?: Ref<HTMLDivElement>;
 }
 
 /**
@@ -41,24 +31,18 @@ export interface LiveMicrophoneLevelMeterProps {
 export const LiveMicrophoneLevelMeter: FC<LiveMicrophoneLevelMeterProps> = ({
   deviceId,
   active,
-  className,
-  ref,
 }) => {
   const state = useMicrophoneLevel(deviceId, active);
-  return <MicrophoneLevelMeter state={state} className={className} ref={ref} />;
+  return <MicrophoneLevelMeter state={state} />;
 };
 
 export interface MicrophoneLevelMeterProps {
   state: MicrophoneState;
-  className?: string;
-  ref?: Ref<HTMLDivElement>;
 }
 
 /** The input level of a microphone, or why there is none. */
 export const MicrophoneLevelMeter: FC<MicrophoneLevelMeterProps> = ({
   state,
-  className,
-  ref,
 }) => {
   const { t } = useTranslation();
   // Bars keep one size, so their count follows the width. Starts full so the
@@ -104,7 +88,7 @@ export const MicrophoneLevelMeter: FC<MicrophoneLevelMeterProps> = ({
   }, [state, barCount, t]);
 
   return (
-    <div ref={ref} className={classNames(styles.meter, className)}>
+    <div className={styles.meter}>
       <MicOnIcon className={styles.icon} aria-hidden />
       {state.type !== "level" ? (
         <Text size="sm" className={styles.message}>

vite-component-dev.config.ts

@@ -38,8 +38,21 @@ export default defineConfig(({ mode }) => {
     ...base,
     root: "component/dev",
     // The same scoping the library build applies, so the harness shows what a
-    // host will get — including whether its own page is left alone
-    css: { postcss: { plugins: [scopeStylesToRoot()] } },
+    // host will get — including whether its own page is left alone. The host's
+    // own stylesheets, Compound's among them, stay unscoped, as on a real host.
+    css: {
+      postcss: {
+        plugins: [
+          scopeStylesToRoot({
+            exclude: [
+              /component[\\/]dev[\\/]/,
+              /@vector-im[\\/]compound-/,
+              /@fontsource[\\/]/,
+            ],
+          }),
+        ],
+      },
+    },
     // So that the harness can read the same config.json the standalone app
     // does, if the developer has written one
     publicDir: "../../public",