/**
 * Registry of active droppable zones for keyboard navigation (#24).
 *
 * Droppables register on mount and unregister on destroy. Keyboard sessions
 * query this list (sorted by geometry) instead of inventing list indexes.
 *
 * @module dnd-registry
 */
import type { DragDropState } from '../types/index.js';
export type DroppableDirection = 'vertical' | 'horizontal' | 'grid';
export interface DroppableRegistration {
    /** DOM node for this drop zone */
    element: HTMLElement;
    /** Container id (same as droppable options.container) */
    container: string;
    direction: DroppableDirection;
    disabled: boolean;
    /**
     * Apply or clear visual hover for keyboard preview.
     * position is used for drop indicators when hovering.
     */
    setKeyboardHover: (active: boolean, position?: 'before' | 'after' | null) => void;
    /**
     * Commit a drop using the same pipeline as pointer/HTML5.
     * Receives a snapshot of dndState at drop time.
     */
    commitDrop: (state: DragDropState) => void | Promise<void>;
}
export declare function registerDroppable(entry: DroppableRegistration): void;
export declare function unregisterDroppable(entry: DroppableRegistration): void;
export declare function getRegisteredDroppables(): DroppableRegistration[];
/**
 * Returns enabled droppables sorted along an axis for keyboard stepping.
 * Nested parents that fully contain a registered child are omitted so the
 * deepest zones win (same spirit as #27).
 */
export declare function listKeyboardTargets(direction?: DroppableDirection): DroppableRegistration[];
/**
 * Find the index of a registration that owns `element` or contains it.
 */
export declare function indexOfElement(targets: DroppableRegistration[], element: HTMLElement | null): number;
/** Clear keyboard hover on all registered droppables. */
export declare function clearAllKeyboardHovers(): void;
/** Testing helpers */
export declare const _testing: {
    clearAll(): void;
    size(): number;
};