/**
 * A helper class for checking whether the tab key is being pressed, and whether
 * the direction is reversed (by having shift pressed).
 *
 * @category Helper
 */
export declare class TabKeyHelper {
    private lastTabEvent;
    private tabState;
    private references;
    private downListener;
    private upListener;
    private focusListener;
    private blurListener;
    private windowFocused;
    private waitQueue;
    constructor();
    private handleTabEvent;
    get pressed(): boolean;
    get directionReversed(): boolean;
    isTabInitiatedFocus(): Promise<boolean>;
    ref(key: unknown): void;
    unref(key: unknown): void;
}
/**
 * Get the global TabKeyHelper
 *
 * @category Helper
 */
export declare function getTabKeyHelper(): TabKeyHelper;