import type { ReactiveController, ReactiveControllerHost } from 'lit';
/**
 * Configuration for {@link ListboxNavController}. All accessors are read lazily,
 * so the host can back them with getters over its own reactive state.
 */
export interface ListboxNavConfig {
    /** Stable id of the `role="listbox"`; option ids derive from it. */
    listboxId: string;
    /** Number of currently navigable options. */
    getCount: () => number;
    /** Whether the option at `index` is disabled (skipped while navigating). */
    isDisabled: (index: number) => boolean;
    /** Whether the listbox is currently open. */
    isOpen: () => boolean;
    /** Open the listbox — called when a navigation key is pressed while closed. */
    open: () => void;
    /** The rendered option elements, in order, for scroll-into-view. */
    getOptionElements: () => ArrayLike<HTMLElement> | null | undefined;
}
/**
 * Owns roving `aria-activedescendant` navigation for the combobox/listbox
 * pattern: Arrow Up/Down move a virtual cursor over a `role="listbox"` while DOM
 * focus stays on the host input, skipping disabled options and scrolling the
 * active one into view. Enter/Escape/Tab stay with the host, which owns
 * commit/close semantics.
 *
 * Home/End are intentionally not handled — an editable combobox reserves them
 * for the text cursor (ARIA APG). Shared by `l-combobox` and (future) `l-select`.
 */
export declare class ListboxNavController implements ReactiveController {
    private host;
    private config;
    /** Index of the active option, or `-1` when none is active. */
    activeIndex: number;
    constructor(host: ReactiveControllerHost, config: ListboxNavConfig);
    hostConnected(): void;
    /** The DOM id for the option at `index` (matches the rendered option `id`). */
    optionId(index: number): string;
    /** `aria-activedescendant` value for the input, or `undefined` when none. */
    get activeDescendant(): string | undefined;
    /** Clear the active option. */
    reset(): void;
    /** Set the active option explicitly (e.g. pre-activate the current value). */
    setActive(index: number): void;
    /** Move the active option by `diff`, opening the listbox first if closed. */
    move(diff: 1 | -1): void;
    /**
     * Handle a keydown for listbox navigation. Returns `true` when the key was
     * consumed, so the host can early-return before its own Enter/Escape/Tab
     * handling.
     */
    onKeyDown(e: KeyboardEvent): boolean;
    private _step;
    private _scrollActiveIntoView;
}
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