const React = window.React; class HitBox extends React.Component { state = { x: 0, y: 0, }; static defaultProps = { onMouseMove: n => n, }; onMove = event => { this.setState({x: event.clientX, y: event.clientY}); this.props.onMouseMove(event); }; render() { const {x, y} = this.state; const boxStyle = { padding: '10px 20px', border: '1px solid #d9d9d9', margin: '10px 0 20px', }; return (

Trace your mouse over this box.

Last movement: {x},{y}

); } } export default HitBox;