[Jason Morse (JasonVMo)]

Platforms Impacted

• iOS
• macOS
• win32 (Office)
• windows
• android

Description of changes

Adds the agentic Popover (#4236), Menu (#4232), MenuButton (#4231), and Dropdown (#4224) on macOS (Fabric and Paper), Windows Fabric, and Office Win32, built from owner-approved contracts. All four are exported from the @fluentui-react-native/components root along with their public types. Popover, Menu, MenuButton, Dropdown, MenuItem, ListboxItem, and Input are ratified as implemented: every requirement names realized evidence.

Summary

• Popover (Components: Generate Popover #4236): a Button trigger slot and a token-styled surface in native-core's modern Callout, with
  controlled or uncontrolled presence, entry focus on the first eligible content or a fallback surface stop, and focus
  return on Escape or caller close.
• Menu (Components: Generate Menu #4232) and MenuButton (Components: Generate MenuButton #4231): a shared popup family with two-level submenus declared through MenuItem's
  submenu prop, hover-open with platform delays, type-ahead, Home and End, discoverable disabled rows (R2), and native
  Tab continuation. MenuButton composes Button with a static chevron.
• Dropdown (Components: Generate Dropdown #4224): a combobox trigger with Input's outline or underline chrome opens a list of ListboxItem
  options, with single or multiple selection, controlled or uncontrolled selection and presence, a placeholder, and a
  count summary. ListboxItem gains a value prop that binds it to the list.
• Native-core: the modern Callout gained first and last entry focus, truthful dismissal reasons,
  tabNavigation with the tab-forward and tab-backward reasons, transparent content-drawn surfaces, nested-popup
  close and light-dismiss rules, and Paper command ordering through UI-manager blocks. Windows Fabric gained rounded
  popup windows with platform shadows, anchor-press handling, and a Tab message hook. New /win32 Callout and
  FocusZone adapters target the Office host's legacy registrations.
• Shared popup controllers: Popover, Menu, and Dropdown read one platform popup host (common/popupHost) instead
  of five adapter files each, and share a presence latch (usePopupPresence). Menu and Dropdown also share the
  list-popup trigger controller (usePopupTrigger), the popup layout styles, and the ref and handler composition helpers.
  Dropdown reuses Input's visual-state resolution. Behavior is unchanged.
• Framework Base and leaves: disabledFocusable for MenuItem, Input's variant focus treatment, and shared
  triggerExpandActions that declare Win32 Expand and Collapse.
• Desktop driver: Windows window activation accepts owned popups, subtree walks retry on closing popups, and
  layout characters type as virtual keys.

Findings worth reviewing

• Yoga's default errata let flexGrow rows fill a fit-content popup to the window width. Menu and Dropdown size their
  content with a row wrapper that uses overflow: 'scroll', and host nested popups in a wide absolute View.
• Callout's popup-wide first/last search stops at a focusable FocusZone, so Menu entry focus uses FocusZone
  commands.
• macOS Paper insets ScrollView content by the size of legacy scrollers (the style used while a mouse is attached),
  even while they are hidden. The Dropdown list therefore never requests a horizontal scroller and requests a vertical
  one only while its options overflow. Before this, Paper options were 17 points narrower than the list and the list
  was 17 points taller than its options. Fabric always uses overlay scrollers.
• RNW's portal lays out its child as a layout root, so Dropdown's trigger-width floor is a zero-height child rather
  than minWidth.
• The Callout placement regressions assumed room below the anchor. On the hosted runner's small display, the owner
  window sat low enough that native placement correctly flipped the popup above the anchor, which put it 267 points
  off. The regressions now move the owner window to the top of its screen first and restore it afterward.
• Popover keeps its own trigger logic. It requests no pointer focus, holds focus per presentation, falls back to the
  surface, and does not restore focus after an assistive collapse. On Win32 it also keeps the raw Callout, because
  requestFocus('first') is unsupported when initialFocus is 'none'.
• macOS driver: switchToWindow makes the owner window key, so story cases send keys before reading popup semantics,
  or act with the pointer inside the popup.

Deferred divergences and follow-ups

Item	Components	Tracking
Owner-relative Tab and Shift+Tab	Popover, Menu, Dropdown	#4377. Shift+Tab from a list or menu focuses the trigger instead of the view before it.
Edge margins	Popover, Menu, Dropdown	#4375. Native clamping aligns popups with the work-area edge without a margin.
Submenu intent on macOS	Menu	menu-submenu-intent: hover switching is delay-only; add a native pointer-travel signal.
Motion and the Popover arrow	All	Presentation is instant, which equals reduced motion. Revisit when Flex motion is final.
Context menus and point anchors	Menu	#4383 (D13).
Office Win32 host improvements	All	#4384 (R1, R3): honor gapSpace, per-pixel transparency, classified dismissals, FocusZone Home and End, trigger restoration on close, Tab past the owner, and one pointer enter without a leave. Each lets an adapter drop a workaround.
Dropdown tag strip	Dropdown	dropdown-token-strip: needs a reviewed Tag-based design.
RNmacOS renderer patch	MenuItem, Input, Dropdown	The root Yarn patch to RNmacOS 0.81.9 (Fabric AX roles and state, TextInput Tab stop, read-only editor) must go upstream or into each consuming host before release.
Office Apple runtime	All	test:apple-integration is a source probe; no Office runtime has run these components.
Controlled close veto	Popover	A caller that vetoes a trigger close keeps a stale close cause until the next open; recorded, not observed natively.
Win32 popup shadow	All	A one-pixel shadow artifact can appear at a bottom corner of the Win32 popup.

Known pre-existing failures

• Windows lint-repo (Knip): knip.config.ts builds workspace keys with backslashes, so imported dependencies in
  unchanged packages read as unused. It passes on macOS.
• Windows components-input--focus-treatment failed before this work.
• The Windows node test controller occasionally exits with 0xC0000409 after the Dropdown Default story while the app
  stays responsive; reruns pass.

Verification

Shared popup controllers and CI fix (5f36f17), macOS, October 22, 2026

Check	Result
Fabric smoke --macos --mode stories-and-tests	Passed, zero skips: Dropdown 8/8, Menu 8/8, MenuButton 4/4, MenuItem 3/3, Popover 5/5, Input 4/4, native-modern-callout 16/16.
Paper prep --macos --paper, then smoke --macos --paper with the same selectors	Passed, zero skips: the same counts.
CI Callout placement failure (y off by 267)	Reproduced locally with the owner window low on the display; it passes after the fix on both renderers.
yarn workspace @fluentui-react-native/components test, lint, check:spec-contracts, report:spec-source-drift --offline --write	Passed: 66 suites, 561 tests; 24 contracts; the drift report is unchanged.
yarn workspace @fluentui-react-native/native-core test and lint	Passed: story typecheck, ownership, and 56 Jest tests.
yarn clean-lage-cache then yarn lage buildci	Passed: 171 tasks, none skipped or failed; also yarn change:check and git diff --check.
PR CI at 5f36f17	Passed: all 18 checks, including macOS and macOS Paper Storybook, Windows and Win32 Storybook, and iOS.

Final commit (5cdbcad), macOS

Check	Result
yarn workspace @fluentui-react-native/components test	Passed: 66 suites, 561 tests, including the root-export test.
check:spec-contracts and report:spec-source-drift --offline --write	Passed: 24 contracts validated.
yarn clean-lage-cache then yarn lage buildci	Passed: 171 tasks, none failed or skipped.

Validation: macOS, October 21, 2026

macOS 27.0.1 (26A434), arm64, Xcode 26.4.1, Swift 6.3.1, RNmacOS 0.81.9 with the checked-in patch, Keyboard navigation
on (AppleKeyboardUIMode=3). Storybook commands use
yarn workspace @fluentui-react-native/agentic-components-storybook with STORYBOOK_SMOKE_TAG=story.

Check	Result
Fabric storybook prep --macos, build --macos, smoke --macos --mode stories-and-tests	Passed, zero skips: Dropdown 8/8, Menu 8/8, MenuButton 4/4, MenuItem 3/3, Popover 5/5, native-modern-callout 16/16, native-callout 2/2, native-modern-focuszone 4/4, components-*--*focus* 16/16; 199 stories rendered.
Paper prep --macos --paper, build --macos --paper, then the same selectors with --paper	Passed, zero skips: the same counts. One native-modern-callout run hit a driver pointer-move error; the rerun passed 16/16.
Dropdown list measurement after the scroller fix, both renderers	Observed: a 240×250 list with 230-point-wide, 40-point-tall options inside 4-point padding and a 1-point border.
Driver captures of the Dropdown trigger gallery, the open list, and the focus ring	Observed: outline and underline, sizes, selected, error, and disabled triggers render correctly; the ring is correct once its animation settles.
yarn workspace @fluentui-react-native/native-core test:apple-integration	Passed.
Components test, lint, check:spec-contracts	Passed: 66 suites, 561 tests, 8 snapshots.
yarn clean-lage-cache then yarn lage buildci	Passed: 171 tasks, zero skipped, pending, aborted, or failed; also storybook bundle --macos, app lint, yarn check-agent-instructions, yarn change:check, git diff --check.
ListboxItem story cases	None defined; its stories render. LBI-006 runs through the Dropdown cases.

Validation: Windows Fabric and Office Win32, October 19 to 21, 2026

Check	Result
Windows smoke --windows, Menu, MenuButton, MenuItem, Popover, Callout, and FocusZone	Passed: Menu 8/8, MenuButton 4/4, MenuItem 3/3, Popover 5/5, native-callout 2/2, native-modern-callout 16/16, native-modern-focuszone 4/4.
Win32 smoke --win32, Menu family, Popover, and native-callout	Passed: Menu 8/8, MenuButton 4/4, MenuItem 3/3, Popover 5/5, Callout 2/2.
desktop-focus cases on Menu, MenuButton, MenuItem, Popover, ListboxItem, and Dropdown	Passed: 26/26 on Windows Fabric and 26/26 on Office Win32, before the macOS changes to the Dropdown cases.
Components, native-core, and desktop-driver lint and test; check:spec-contracts	Passed: components 560 tests; native-core 18 ownership and 56 Jest tests; driver 61 with 3 skipped.
yarn clean-lage-cache then yarn lage buildci	Knip failed, pre-existing on Windows (backslash workspace keys). Every other target passed; a deadline-sensitive storybook-desktop contract passed when rerun alone.

Windows Fabric and Office Win32 rerun at 8e32a1a, October 21, 2026

Check	Result
smoke --windows and smoke --win32: Dropdown, Menu, MenuButton, MenuItem, Popover	Passed on both, zero skips: Dropdown 8/8 (including the new Tab and Shift+Tab, trigger-close, and LongList cases), Menu 8/8, MenuButton 4/4, MenuItem 3/3, Popover 5/5.
Full indexed-story traversal	Passed: 192 stories on Windows, 166 on Win32, including ListboxItem.
First Win32 attempt	Node controller exited with 0xC0000409 after 14 passing cases; the full retry passed without source changes.

Not run

• Interactive Windows Fabric and Office Win32 smokes of the shared popup controllers (5f36f17). The refactor
  replaces the Windows and Win32 adapters with common/popupHost.windows.ts and .win32.ts, and hosted CI disables
  keyboard and physical clicks on those lanes. Rerun the popup-family desktop-focus cases on the Windows machine.
• VoiceOver, Narrator, and accessibility-action invocation on any endpoint.
• Office runtime hosts on macOS; the high-contrast, scaling, and theme matrix.

The four components are exported before VoiceOver, Narrator, and visual-matrix qualification. The RNmacOS patch is still a release gate.

Before	After
No Popover, Menu, MenuButton, or Dropdown in the agentic components package	All four are implemented and exported on macOS, Windows, and Win32

Pull request checklist

This PR has considered (when applicable):

• Automated Tests
• Documentation and examples
• Keyboard Accessibility
• Voiceover
• Internationalization and Right-to-left Layouts

[github-actions]

Bundle size report

Tree-shaken, minified production esbuild bundles with React and React Native runtimes externalized.

Scenario	Modules-Mac (Δ)	Modules-Win (Δ)	Size-Mac (Δ)	Size-Win (Δ)
components-button	64 (+2)	65 (+2)	50.63k (+687b)	50.55k (+687b)
components-catalog	214 (+55)	215 (+55)	205.49k (+50.22k)	205.41k (+50.22k)
design-theme-state	34 (+1)	35 (+1)	30.15k (+42b)	30.08k (+42b)
design-themed-root	38 (+1)	39 (+1)	32.12k (+42b)	32.04k (+42b)
design-color-lib	6 (+0)	6 (+0)	6.33k (+0b)	6.33k (+0b)
design-theme-state-legacy-source	35 (+1)	36 (+1)	31.81k (+42b)	31.73k (+42b)
design-legacy-theme-from-flex	58 (+1)	59 (+1)	97.77k (+42b)	97.63k (+42b)

The job is advisory: size changes are reported but do not fail the pull request. Bundle or analysis errors still fail.

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