import { ReactiveController, ReactiveElement } from 'lit';
/**
 * Adds expanded support for interactive custom elements including CSS State psuedo-selector :state(expanded) and aria-expanded.
 * https://developer.mozilla.org/en-US/docs/Web/API/ElementInternals/states
 * https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Attributes/aria-expanded
 */
export declare function stateExpanded<T extends Expanded>(): ClassDecorator;
export type Expanded = ReactiveElement & {
    expanded: boolean;
    readOnly?: boolean;
    _internals?: ElementInternals;
};
export declare class StateExpandedController<T extends Expanded> implements ReactiveController {
    private host;
    constructor(host: T);
    hostConnected(): void;
    hostUpdated(): void;
}
