import type { NavigationState } from "./types.js";
/**
 * Computes the current navigation state of a scroller via native reads. Uses
 * the cached, scroll-invariant marker list and geometry when available so the
 * per-frame work on the scroll hot loop is free of DOM queries, style reads,
 * sorts, and allocations — only the scroll metrics are read live.
 */
export declare function getNavigationState(scroller: HTMLElement): NavigationState;
type Subscriber = (state: NavigationState) => void;
/**
 * Subscribes to everything that can change the navigation state (scrolling,
 * snap settling, resizes, and added/removed slides) and pushes a fresh
 * `NavigationState` to the callback, coalesced to one update per frame. Returns
 * a cleanup function that removes the subscriber.
 *
 * Ref-counted per scroller: multiple controls pointing at the same scroller
 * share one observer set and one frame loop, computing the state once and
 * fanning it out to every subscriber. The observers (and the per-scroller snap
 * cache they maintain — off the scroll path, since snap geometry only changes
 * on resize/mutation) are torn down once the last subscriber unsubscribes.
 */
export declare function observeNavigationState(scroller: HTMLElement, callback: Subscriber): () => void;
export {};