import type { Printable } from 'tree-dump';
import type { UiLifeCycles } from '../types';
export interface KeyControllerOpts {
    source: HTMLElement;
}
/**
 * Keeps track of all pressed down keys.
 */
export declare class KeyController implements UiLifeCycles, Printable {
    protected readonly opts: KeyControllerOpts;
    /**
     * All currently pressed keys.
     */
    readonly pressed: Set<string>;
    constructor(opts: KeyControllerOpts);
    start(): () => void;
    /** ----------------------------------------------------- {@link Printable} */
    toString(tab?: string): string;
}