import { Coords3D } from './coordinates';
/**
 * Keyboard event with a key code and coordinates if the device geometry can be figured out with any confidence.
 */
export type CoordinateKeyboardEvent = {
    code: string;
    coordinates?: Coords3D;
};
export type KeyupCallback = () => void;
export type KeydownCallback = (event: CoordinateKeyboardEvent) => KeyupCallback;
/**
 * Keyboard event listener that filters out repeated keydown events and normalizes keycodes to coordinates.
 * The Shift keys toggle 'sustain'.
 */
export declare class Keyboard {
    private keydownCallbacks;
    private keyupCallbacks;
    private activeKeys;
    private pendingKeys;
    private stickyKeys;
    private _keydown?;
    private _keyup?;
    private log;
    /**
     * Construct a new keyboard event listener.
     * @param autobind Start listening to "keydown" and "keyup" events immediately.
     * @param log Logging function.
     */
    constructor(autobind?: boolean, log?: (msg: string) => void);
    /**
     * Stop listening to "keydown" and "keyup" events if constructed with `autobind = true`.
     */
    dispose(): void;
    /**
     * Register a listener for processed keydown events.
     * @param listener Function to call when a new key is pressed.
     */
    addKeydownListener(listener: KeydownCallback): void;
    /**
     * Unregister a listener for processed keydown events.
     * @param listener Callback registered with {@link Keyboard.addKeydownListener}.
     */
    removeEventListener(listener: KeydownCallback): void;
    private fireKeydown;
    private fireKeyup;
    /**
     * Listener to be registered with `window.addEventListener("keydown", ...)`.
     * @param event Keyboard event of a key being pressed down.
     */
    keydown(event: KeyboardEvent): void;
    /**
     * Listener to be registered with `window.addEventListener("keyup", ...)`.
     * @param event Keyboard event of a pressed key being released.
     */
    keyup(event: KeyboardEvent): void;
    /**
     * Release keys sustained due to being pressed down with 'Shift'.
     */
    deactivate(): void;
}