How to change the style of one element when I hover another element (ReactJS)?

Question

So basically when i hover over "drive" option which is a h1, i want a div container to appear that contains several other in detail options. Then if i click on "ride" option which is another h1, i want a div to appear as well that has more details and options. Only one can be chosen at a time, either ride/drive, but if i hover over ride, then the div that appears needs to stay until the mouse is off the div, if i hover over drive, then the drive div needs to appear. Hope you guys can help! Here is my code

import React, { Component } from 'react';
import './App.css';

class Header extends Component {
  render() {
    return (
      <div className="Nav">
        <header className="Nav-header">
          <h1 className="Nav-title">Halcon</h1>
          <p className="Nav-drive"><a href="*" className="Nav-link" onMouseEnter={this.mouseOver.bind(this)} onMouseLeave={this.mouseOut.bind(this)}>Drive</a></p>
          <p className="Nav-seperator">|</p>
          <p className="Nav-ride"><a href="*" className="Nav-link">Ride</a></p>
        </header>
         // Div i want to appear if Drive is hovered
        <div className="Drive-toggle">
          <h3>Why drive with us?</h3>
          <h3>Safety</h3>
          <h3>Requirements to Drive</h3>
          <h3>Driver App</h3>
          <h3>Driver - Log In</h3>
        </div>
        // Div i want to appear if Ride is hovered
        <div className="Ride-toggle">
          <h3>Why drive with us?</h3>
          <h3>Safety</h3>
          <h3>Requirements to Drive</h3>
          <h3>Driver App</h3>
          <h3>Driver - Log In</h3>
        </div>

      </div>
    );
  }
}

export default Header;

Answer 1

You can use the state to store a Boolean value of hovered, and use the onMouseEnter and onMouseLeave to update the state.

Then you can render a style, a CSS class or a component conditionally.

Here is a small running example:

class App extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      hovered: false
    };
  }

  onMouseEnter = e => {
    this.setState({ hovered: true });
  };

  onMouseLeave = e => {
    this.setState({ hovered: false });
  };

  render() {
    const { hovered } = this.state;
    const style = hovered ? { backgroundColor: "#333", color: "#fff" } : {};
    return (
      <div>
        <div onMouseEnter={this.onMouseEnter} onMouseLeave={this.onMouseLeave}>
          Hover over me!
        </div>
        <hr />
        <div style={style}>Was it hovered?</div>
        <hr />
        {hovered && <div>Yes!!</div>}
      </div>
    );
  }
}

ReactDOM.render(<App />, document.getElementById("root"));

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="root"></div>