import { ElementRef, EventEmitter } from '@angular/core';
import { TreeNodeEndDirective } from './tree-node-end.directive';
import * as i0 from "@angular/core";
/** A node of an `epag-tree`. */
export interface EpagTreeNode {
    /** Unique across the whole tree. */
    id: string;
    /** Text shown on the row, and the row's accessible name. */
    label: string;
    /** Child nodes. A node with this array, even an empty one, is a folder; without it, a leaf. */
    children?: EpagTreeNode[];
    /** When true, the user can select the node. Defaults to false. */
    selectable?: boolean;
}
/** A node drawn as a folder. */
type FolderNode = EpagTreeNode & {
    children: EpagTreeNode[];
};
/**
 * Hierarchical data drawn as expandable rows, with single selection.
 *
 * Name the tree with `aria-label` or `aria-labelledby` on `<epag-tree>` itself.
 *
 * @example
 * ```html
 * <epag-tree
 *   aria-label="Accounts"
 *   [nodes]="accounts"
 *   [(selectedId)]="selectedAccountId"
 *   [(expandedIds)]="expandedIds">
 * </epag-tree>
 * ```
 */
export declare class TreeComponent {
    private readonly host;
    /**
     * The top-level nodes. Pass a new array to change the tree: the component uses OnPush, so
     * nodes or children changed in place are not picked up.
     */
    nodes: EpagTreeNode[];
    /** Id of the selected node, or null when nothing is selected. */
    set selectedId(id: string | null | undefined);
    /** Emits the id of the node the user selects. */
    readonly selectedIdChange: EventEmitter<string>;
    /** Ids of the nodes whose children are shown. */
    set expandedIds(ids: string[] | null | undefined);
    /** Emits every expanded id whenever the user expands or collapses a node. */
    readonly expandedIdsChange: EventEmitter<string[]>;
    protected readonly role = "tree";
    /** Template drawn at the end of every row. */
    protected nodeEnd?: TreeNodeEndDirective;
    /** The row the user last moved focus to; it keeps the tab stop while focus stays in the tree. */
    protected activeId: string | null;
    private readonly treeId;
    /** Node id → a key safe inside DOM ids: node ids may hold spaces, which split ARIA id lists. */
    private readonly domKeys;
    private expanded;
    private selected;
    /** The selection as the host last passed it, which may lag behind `selected`. */
    private hostSelected;
    private cachedView?;
    constructor(host: ElementRef<HTMLElement>);
    /** The one row a Tab keypress lands on (roving tabindex). */
    protected get tabStopId(): string | undefined;
    protected onKeydown(event: KeyboardEvent): void;
    /** Once focus leaves the tree, coming back lands on the selected row, not the last one visited. */
    protected onFocusout(event: FocusEvent): void;
    protected onRowClick(event: MouseEvent, node: EpagTreeNode): void;
    protected onChevronClick(event: MouseEvent, node: EpagTreeNode): void;
    protected trackById(_index: number, node: EpagTreeNode): string;
    protected labelId(node: EpagTreeNode): string;
    protected endId(node: EpagTreeNode): string;
    protected isFolder(node: EpagTreeNode): node is FolderNode;
    protected isExpanded(node: EpagTreeNode): boolean;
    protected isSelected(node: EpagTreeNode): boolean;
    /**
     * The rendered rows and the tab stop. Every row reads the tab stop on every change detection,
     * so they are derived once per state change rather than once per row.
     */
    private view;
    /** What clicking a row, or pressing Enter or Space on it, does: select it, else expand or collapse it. */
    private activate;
    /** Whether an element is one of this tree's rows, rather than a row of a tree nested inside it. */
    private ownsRow;
    private domKey;
    private focusNode;
    private select;
    private toggle;
    static ɵfac: i0.ɵɵFactoryDeclaration<TreeComponent, never>;
    static ɵcmp: i0.ɵɵComponentDeclaration<TreeComponent, "epag-tree", never, { "nodes": { "alias": "nodes"; "required": false; }; "selectedId": { "alias": "selectedId"; "required": false; }; "expandedIds": { "alias": "expandedIds"; "required": false; }; }, { "selectedIdChange": "selectedIdChange"; "expandedIdsChange": "expandedIdsChange"; }, ["nodeEnd"], never, false, never>;
}
export {};