feat(ScrollArea): add getScrollElement virtualize option

[IgorShevchik]

Upstream

a84de85 — feat(ScrollArea): add getScrollElement virtualize option (#6650)

Change

Lets ScrollArea virtualize against an external ancestor scroll container instead of its own root viewport:

• new getScrollElement?: () => Element | null in ScrollAreaVirtualizeOptions (removed from the Omit exclusion)
• isExternalScroll computed + a getScrollElement() resolver (external el when provided, else rootRef.$el), used by the virtualizer
• getVirtualItemStyle subtracts scrollMargin from virtualItem.start in external mode (offset) so items sit inline
• resize-observer moved from a one-shot onMounted to watch(getScrollElement, …, { immediate: true }) so it re-observes when the scroll element changes (onMounted import dropped)
• root gets overflow: visible in external mode (it no longer owns the scroll)

Component — 1:1

b24ui's ScrollArea.vue matched upstream's pre-change structure; all script + the :style change applied verbatim (only the pre-existing b24ui.root class binding differs, untouched).

Tests

Added the with virtualize external scroll element renderEach case verbatim (getScrollElement: () => document.body, scrollMargin: 20). 2 snapshots regenerated — the new case renders style="overflow: visible;" on the root, the feature demonstrating itself. Full suite 5145 passed (+2 vs 5143) / 6 skipped.

Docs — adapted & trimmed (deviation)

Ported the ### With external scroll element md section (badge New, per b24ui convention, not upstream's Soon) with the same explanation + note/caution. The example is trimmed to the feature core: an external scroll container owning the scroll, a sticky header measured via useElementSize (border-box) feeding scrollMargin, and B24ScrollArea with { getScrollElement, scrollMargin, estimateSize, skipMeasurement } over B24PageCard/B24User rows (same dummyjson fetch b24ui's ScrollAreaInfiniteScrollExample already uses) + a "Top" button (B24Button, ArrowToTheTopIcon, color="air-tertiary").

Dropped upstream's incidental "find" toolbar (search input + prev/next-match buttons + result counter + UBadge/UFieldGroup) — demo sugar, not part of the feature, and its neutral/subtle/outline + iconify mappings carry design-judgment risk in a non-test-validated example. Can follow as a separate doc enhancement if wanted.

useElementSize is imported explicitly from @vueuse/core (not auto-imported in b24ui docs).

Maps (§4)

Added 3 icon-map.json entries: i-lucide-arrow-up-to-line → actions/ArrowToTheTopIcon, i-lucide-chevron-up → outline/ChevronTopSIcon (b24icons names up-chevrons "Top"), i-lucide-search → main/Search2Icon.

Verify (CI=true)

dev:prepare · lint · typecheck (docs example compiles) · test · build — all green.

Ledger

• .sync/log/a84de85….md — port rationale
• .sync/nuxt-ui.json — add a84de85 as port, advance cursor (= upstream v4 HEAD); reconcile prior df099a5 → PR chore(deps): update actions/checkout action to v7 #232 / 49d01ae6.

🤖 Generated with Claude Code

---

Generated by Claude Code