Scroll up button

Scroll up button

import React from 'react';
import Button from '@material-ui/core/Button';
import ExpandLessIcon from '@material-ui/icons/ExpandLess';

class ScrollUpButton extends React.Component {
    constructor(props) {
        super(props);
        this.state = {
            scrollC: 0
        };

        this.handleScrolltoTop = this.handleScrolltoTop.bind(this);
        this.onScroll = this.onScroll.bind(this);
    }

    componentDidMount() {
        window.addEventListener("scroll", this.onScroll);
    }

    onScroll() {
        this.setState({
            scrollC: window.scrollY
        });
    }
    
    handleScrolltoTop() {
        if(window !== undefined) {
            window.scrollTo({top: 0, behavior: (this.props.behavior?this.props.behavior:'auto')})
        }
    }

    render() {

        const { 
            IconSize,
            appearCoordinate,
        } = this.props;

        return(
            <React.Fragment>

                <div>

                {this.state.scrollC > (appearCoordinate?appearCoordinate:1200) ?
                    <Button 
                        onClick={this.handleScrolltoTop}
                    >
                        <ExpandLessIcon style={{fontSize:IconSize?IconSize:'60px'}}/>
                    </Button>:''
                }

                </div>

            </React.Fragment>
        )
    }
}

export default ScrollUpButton;