import { TreeOptions } from './tree.types';
interface TreeNode {
    el: HTMLElement;
    value: string;
    checkbox: HTMLInputElement | null;
    toggle: HTMLElement | null;
    group: HTMLElement | null;
    parent: TreeNode | null;
    children: TreeNode[];
}
/**
 * Headless tree / nested list. Handles expand-collapse, tri-state checkbox
 * selection with parent/child propagation, ARIA wiring and keyboard navigation.
 *
 * Markup:
 * ```html
 * <ul data-c42-tree>
 *   <li data-c42-tree-item data-value="p1">
 *     <div data-c42-tree-row>
 *       <button data-c42-tree-toggle></button>
 *       <input type="checkbox" data-c42-tree-checkbox /> Parent
 *     </div>
 *     <ul data-c42-tree-group>
 *       <li data-c42-tree-item data-value="c1">
 *         <div data-c42-tree-row><input type="checkbox" data-c42-tree-checkbox /> Child</div>
 *       </li>
 *     </ul>
 *   </li>
 * </ul>
 * ```
 */
export declare class Tree {
    private readonly root;
    private readonly treeSelection;
    private readonly expandAll;
    private nodes;
    private cleanups;
    constructor(root: HTMLElement, options?: TreeOptions);
    private init;
    private build;
    private get flat();
    private setupNode;
    private setExpanded;
    toggleNode(node: TreeNode): void;
    private onCheckboxChange;
    private propagateDown;
    private recomputeAncestors;
    private recomputeNode;
    private recomputeAll;
    private visibleNodes;
    private nodeFromActive;
    private focusNode;
    private onKeydown;
    private emit;
    get value(): string[];
    on<E extends Event = Event>(event: string, handler: (event: E) => void): () => void;
    destroy(): void;
}
export {};