// Parent Component

class Root extends React.Component {
  constructor(props) {
    super(props);
    this.state = { refresh: true };
    // Parents non-state variable.
    this.submitBtnVisibility = { visibility1: 1, visibility2: 2 };

  }

  componentDidMount() {
    console.log("Root componentDidMount ");
  }

  componentDidUpdate(prevProps, prevState) {
    console.log("Root componentDidUpdate ", prevProps, prevState);
  }

  handleonclick = () => {
    console.log(" Root Btn Clicked");
    //this.setState({ var1: 5 });  -> If I enable this line , child is getting rendered
    this.submitBtnVisibility.visibility1 = 5;
  };
  render() {
    console.log(" Root Render ");

    return (
      <div className={classes.uploadContainerArea}>
        <Btncomponent visibility={this.submitBtnVisibility} />
        <button className={classes.btnroot} onClick={this.handleonclick}>
          {" "}
          Root Btn{" "}
        </button>
      </div>
    );
  }
}

// Child Component

class Btncomponent extends React.Component {
  constructor(props) {
    super(props);
    this.state = { Btnprops: this.props.visibility };
  }

  componentDidMount() {
    console.log("Btncomponent componentDidMount ");
  }

  componentDidUpdate(prevProps, prevState) {
    console.log("Btncomponent componentDidUpdate ", prevProps, prevState);
  }

  static getDerivedStateFromProps(props, state) {
    console.log(" getDerivedStateFromProps ");
    return null;
  }
  shouldComponentUpdate(nextProps, nextState) {
    console.log(" shouldComponentUpdate ");
    return true;
  }
  getSnapshotBeforeUpdate(prevProps, prevState) {
    console.log(" getSnapshotBeforeUpdate ");
    return null;
  }
  render() {
    console.log(" Btncomponent Render ", this.props);

    return <button type="button"> {this.props.visibility.visibility1} </button>;
  }
}