@withViewPort装饰器如何在React中工作?

我正在阅读此装饰程序,发现@withViewPort用法为:

import React from 'react';
import withViewport from 'react-decorators/withViewport';

@withViewport
class MyComponent {
  render() {
    let { width, height } = this.props.viewport;
    return <div>Viewport: {width + 'x' + height}</div>;
  }
}

React.render(<MyComponent />, document.body);

@withViewPort装饰器是如何工作的?它有状态吗?在调整窗口大小时,这些状态会改变吗?