import * as React from 'react'; import { ConfigConsumerProps } from '../config-provider'; export interface BackTopProps { visibilityHeight?: number; onClick?: React.MouseEventHandler; target?: () => HTMLElement | Window; prefixCls?: string; className?: string; style?: React.CSSProperties; visible?: boolean; } export default class BackTop extends React.Component { static defaultProps: { visibilityHeight: number; }; scrollEvent: any; constructor(props: BackTopProps); componentDidMount(): void; componentWillUnmount(): void; scrollToTop: (e: React.MouseEvent) => void; handleScroll: () => void; renderBackTop: ({ getPrefixCls }: ConfigConsumerProps) => JSX.Element; render(): JSX.Element; }