import { BaseTreeItem } from './tree-item.base.js';
import { TreeItemAppearance, TreeItemSize } from './tree-item.options.js';
/**
 * The Fluent Tree Item Element. Implements {@link @microsoft/fast-foundation#BaseTreeItem}.
 *
 * @tag fluent-tree-item
 *
 * @slot - The default slot. Accepts the content of the tree item.
 * @slot start - Content shown before the item label.
 * @slot end - Content shown after the item label.
 * @slot aside - Content shown at the far end of the row.
 * @slot item - Child tree items.
 *
 * @csspart positioning-region - The container for item content and aside regions.
 * @csspart content - The item content region.
 * @csspart chevron - The expand/collapse indicator region.
 * @csspart aside - The trailing aside region.
 * @csspart items - The child items group region.
 *
 * @fires { ToggleEvent } toggle - Fired when expanded state toggles.
 * @fires { Event } change - Fired when selected state changes.
 *
 */
export declare class TreeItem extends BaseTreeItem {
    /**
     * The size of the tree item element
     * @public
     */
    size: TreeItemSize;
    /**
     * Handles changes to the size attribute
     * we update the child tree items' size based on the size
     *  @internal
     */
    protected sizeChanged(): void;
    /**
     * The size of the tree item element
     * @public
     */
    appearance: TreeItemAppearance;
    /**
     * Handles changes to the appearance attribute
     *
     * @internal
     */
    protected appearanceChanged(): void;
    /**
     * child tree items supered change event
     * @internal
     */
    childTreeItemsChanged(): void;
    /**
     * 1. Update the child items' size based on the tree's size
     * 2. Update the child items' appearance based on the tree's appearance
     *
     * @public
     */
    updateSizeAndAppearance(): void;
}