/**
 * 获取或者设置是否由按下键盘获取到焦点
 *
 * @param {boolean?} pressed
 */
export declare function focusKeyPressed(pressed?: boolean): boolean;
export declare function detectKeyboardFocus(instance: {
    keyboardFocusCheckTime: number;
    keyboardFocusMaxCheckTimes: number;
    keyboardFocusTimeout: number;
}, element: HTMLElement, callback: () => void, attempt?: number): void;
export declare function isFocusKey(event: KeyboardEvent): boolean;
export declare function onKeyup(event: KeyboardEvent): void;
export declare function listenForFocusKeys(): void;