react-tetris/src/components/keyboard/button/index.js

import React from 'react';
import cn from 'classnames';
import propTypes from 'prop-types';

import style from './index.less';
import { transform } from '../../../unit/const';

export default class Button extends React.Component {
  shouldComponentUpdate(nextProps) {
    return nextProps.active !== this.props.active;
  }
  render() {
    const {
      active, color, size, top, left, label, position, arrow,
    } = this.props;
    return (
      <div
        className={cn({ [style.button]: true, [style[color]]: true, [style[size]]: true })}
        style={{ top, left }}
      >
        <i
          className={cn({ [style.active]: active })}
          ref={(c) => { this.dom = c; }}
        />
        { size === 's1' && <em
          style={{
            [transform]: `${arrow} scale(1,2)`,
          }}
        /> }
        <span className={cn({ [style.position]: position })}>{label}</span>
      </div>
    );
  }
}

Button.propTypes = {
  color: propTypes.string.isRequired,
  size: propTypes.string.isRequired,
  top: propTypes.number.isRequired,
  left: propTypes.number.isRequired,
  label: propTypes.string.isRequired,
  position: propTypes.bool,
  arrow: propTypes.string,
  active: propTypes.bool.isRequired,
};