/**
 * This can either be a query selector string, a specific HTMLElement, or a
 * function that finds a specific HTMLElement to focus.
 */
export declare type FocusFallback = string | HTMLElement | (() => HTMLElement | null) | null | undefined;
/**
 * This hook is used to focus the previous element when a component unmounts.
 * The default behavior is to store the current activeElement within the
 * document when the component mounts and then try to focus it again when the
 * component unmounts.  You can also provide your own HTMLElement to focus when
 * unmounting.
 *
 * During the unmount phase, it will wait for an animation frame before checking
 * if the fallback element still exists within the page. If it doesn't, it will
 * use the fallback query/element/function to attempt to find another element to
 * focus. If the element exists within the page, it will then finally be
 * focused.
 *
 * The animation frame is unfortunately required for keyboard users as pressing
 * enter key will click the previous element immediately on focus as well.
 *
 * @param disabled Boolean if the focus behavior should be disabled.
 * @param fallback The fallback query, element, or function to use if the
 * previous element no longer exists in the DOM.
 * @param previousElement An optional previous element to focus. If this is
 * omitted, the `document.activeElement` will be used instead.
 */
export default function usePreviousFocus(disabled: boolean, fallback?: FocusFallback, previousElement?: HTMLElement | null): void;