Headless Core — Carousel

Powers Carousel internally. No autoplay timer, no swipe/drag handling, and no transform/scroll math — those are real DOM/timing concerns the consuming component owns. This factory only tracks which index is active and hands back the ARIA wiring.

Usage

import { createCarousel } from '@andersseen/headless-components/carousel';

const carousel = createCarousel({
  slideCount: 5,
  defaultIndex: 0,
  onIndexChange: index => console.log('Active slide:', index),
});

carousel.actions.goToNext();
carousel.queries.isActive(1); // true after the call above

Config

Option	Type	Default	Notes
slideCount	number	0
defaultIndex	number	0	Normalized modulo slideCount on creation.
autoplay	boolean	false	Just a state flag — starting/stopping a timer from it is up to you.
interval	number (ms)	—	Accepted by the config type; not read internally — same reasoning as autoplay.
onIndexChange	(index: number) => void	—

State

activeIndex, slideCount, autoplay.

Actions & queries

Member	Signature	Notes
actions.goToNext() / goToPrev()	() => void	Wraps around at either end.
actions.goToSlide(index)	(index: number) => void	Also wraps — negative or out-of-range indexes are normalized modulo slideCount.
actions.setSlideCount(count)	(count: number) => void	Resets activeIndex to 0 if it’s now out of range.
actions.setAutoplay(v)	(autoplay: boolean) => void
queries.isActive(index)	(index: number) => boolean

Prop-getters

Getter	Returns
getTrackProps(trackId)	aria-live ('off' while autoplay, else 'polite'), aria-label: 'Slides'
getSlideProps(index, label?)	role: 'group', aria-roledescription: 'slide', aria-label (defaults to Slide N), aria-hidden (true for every non-active slide)
getPrevButtonProps(trackId) / getNextButtonProps(trackId)	aria-controls: trackId, aria-label

aria-live switching off during autoplay is deliberate — a screen reader shouldn’t announce every auto-advance, only manual navigation.

Live example

Prev Next

Next steps

Primitives — every factory above follows the same state/subscribe/actions/queries/prop-getter shape this one does.