export declare const off: (element: any, event: any, handler: any) => void;
export declare const on: (element: any, event: any, handler: any) => void;
export declare function preventDefault(e: Event): void;
type objectKeyOnlyCss = {
  [k in keyof CSSStyleDeclaration]?: any;
};
export declare function setStyle(imgElement: HTMLElement | null, styleObj: objectKeyOnlyCss): void;
export declare function setProperties(imgElement: HTMLElement | null, properties: object): void;
export declare function getElementRect(el: Element | null): DOMRect;
export declare function nextTick(fn: () => void): void;
/**
 * check element is hidden by css
 * @param el check el
 * @param  bubblingLevel The level to look up from the current element
 * @returns {boolean}
 */
export declare function isElementHiddenByCss(el: Element | null, bubblingLevel: number): boolean;
/**
 * 判断一个元素是否出现在当前视口中
 * @param el 要判断的元素
 * @returns {boolean}
 */
export declare function isElementInViewport(el: any, bubblingLevel: number): boolean;
export declare function setDataset(el: HTMLElement, key: string, value: string): void;
export declare const slotAssignedElements: (nodes: any[]) => any[];
export declare const addEventListener: (el: any, eventName: string, callback: any, opts?: any) => any;
export {};