/**
 * Coordinates every mounted `Sticky` so ones that overlap horizontally stack
 * underneath each other (in DOM order) instead of pinning to the same spot.
 * Non-overlapping ones (e.g. side-by-side halves under a full-width one) land
 * at the same top instead of being pushed down by each other.
 */
export interface StickyStackMetrics {
    /** Current (unstuck-flow) top of the root element, from getBoundingClientRect. */
    top: number;
    left: number;
    width: number;
    contentHeight: number;
    /** The element this entry sticks relative to (its scroll parent), or null for the viewport.
     *  Stacking only considers overlap between entries sharing the same container — two Stickies
     *  in unrelated scroll panels should never push each other down just because they happen to
     *  share horizontal DOM coordinates. */
    container: HTMLElement | null;
    /** The element the entry is confined to, or null when nothing confines it.
     *  Entries sharing one leave together. */
    boundary: HTMLElement | null;
    /** Bottom edge of that element (less its inset), in the same coordinate space as `top`. */
    boundaryBottom: number | null;
}
export interface StickyStackEntry {
    node: HTMLElement;
    offsetTop: number;
    disabled: boolean;
    getMetrics: () => StickyStackMetrics | null;
}
export interface StickyStackResult {
    isStuck: boolean;
    /** Effective `top` to pin at while stuck — offsetTop plus the height of any stuck, overlapping entries above it. */
    top: number;
}
type ResultListener = (result: StickyStackResult) => void;
declare class StickyStack {
    private entries;
    private listeners;
    private results;
    private rafId;
    private listenerCount;
    schedule: () => void;
    register(entry: StickyStackEntry, onChange: ResultListener): symbol;
    updateEntry(id: symbol, patch: Partial<Pick<StickyStackEntry, 'offsetTop' | 'disabled'>>): void;
    unregister(id: symbol): void;
    recompute: () => void;
    private startListening;
    private stopListening;
}
export declare const stickyStack: StickyStack;
export {};