import { ComputedRef, MaybeRefOrGetter } from 'vue';
/**
 * Shared lifecycle callbacks exposed by headless scroller composables.
 */
export interface ScrollerCallbacks {
    onResize?: () => void;
    onVisible?: () => void;
    onHidden?: () => void;
    onUpdate?: (startIndex: number, endIndex: number, visibleStartIndex: number, visibleEndIndex: number) => void;
}
/**
 * Shared activation flag for headless scroller composables.
 */
export interface ScrollerOptionEnabled {
    /**
     * When `false`, the composable mounts in a passive state: no watchers,
     * observers, scroll/resize listeners, RAFs, or timers are attached, and
     * exported reactive sources stay at their inert defaults. Toggling back
     * to `true` re-arms the scroller without remounting the consumer.
     *
     * Useful for call sites that want a stable composable invocation but
     * conditionally render virtualized output (e.g. an opt-in `virtualize`
     * prop on a wrapping component).
     *
     * @default true
     */
    enabled?: MaybeRefOrGetter<boolean>;
}
/**
 * Common single-object inputs for headless scroller composables.
 *
 * `scrollParent` overrides the auto-detected scroll parent used by page mode
 * (issue #928). Accepts an `HTMLElement` to listen and measure against, or
 * `Window` to force the page itself as the viewport. When omitted, the
 * scroller walks the DOM via `getScrollParent` for the nearest overflow:auto
 * ancestor and falls back to `window`.
 */
export interface ScrollerOptionElements {
    el?: MaybeRefOrGetter<HTMLElement | undefined>;
    before?: MaybeRefOrGetter<HTMLElement | undefined>;
    after?: MaybeRefOrGetter<HTMLElement | undefined>;
    scrollParent?: MaybeRefOrGetter<HTMLElement | Window | undefined>;
}
/**
 * Common single-object callback hooks for headless scroller composables.
 */
export interface ScrollerOptionCallbacks extends ScrollerCallbacks {
}
/**
 * Normalized element refs and callback hooks resolved from either object or legacy positional inputs.
 */
export interface NormalizedScrollerInputs {
    el: ComputedRef<HTMLElement | undefined>;
    before: ComputedRef<HTMLElement | undefined>;
    after: ComputedRef<HTMLElement | undefined>;
    scrollParent: ComputedRef<HTMLElement | Window | undefined>;
    callbacks: ScrollerCallbacks;
}
/**
 * Cache single-object scroller options so getter-based callers do not rebuild the object on every access.
 */
export declare function resolveScrollerOptions<TOptions>(options: MaybeRefOrGetter<TOptions>): ComputedRef<TOptions>;
/**
 * Resolve shared scroller inputs while keeping `items` and DOM refs as separate reactive sources.
 */
export declare function normalizeScrollerInputs<TOptions extends ScrollerOptionElements & ScrollerOptionCallbacks>(options: MaybeRefOrGetter<TOptions>, el?: MaybeRefOrGetter<HTMLElement | undefined>, before?: MaybeRefOrGetter<HTMLElement | undefined>, after?: MaybeRefOrGetter<HTMLElement | undefined>, callbacks?: ScrollerCallbacks): NormalizedScrollerInputs;