content: import React from 'react';
  import PropTypes from 'prop-types';
  import clsx from 'clsx';
  import RadioButtonUncheckedIcon from '../internal/svg-icons/RadioButtonUnchecked';
  import RadioButtonCheckedIcon from '../internal/svg-icons/RadioButtonChecked';
  import withStyles from '../styles/withStyles';
  
  export const styles = theme => ({
    root: {
      position: 'relative',
      display: 'flex',
      '&$checked $layer': {
        transform: 'scale(1)',
        transition: theme.transitions.create('transform', {
          easing: theme.transitions.easing.easeOut,
          duration: theme.transitions.duration.shortest,
        }),
      },
    },
    layer: {
      left: 0,
      position: 'absolute',
      transform: 'scale(0)',
      transition: theme.transitions.create('transform', {
        easing: theme.transitions.easing.easeIn,
        duration: theme.transitions.duration.shortest,
      }),
    },
    checked: {},
  });
  
  /**
   * @ignore - internal component.
   */
  function RadioButtonIcon(props) {
    const { checked, classes } = props;
  
    return (
      <div className={clsx(classes.root, { [classes.checked]: checked })}>
        <RadioButtonUncheckedIcon />
        <RadioButtonCheckedIcon className={classes.layer} />
      </div>
    );
  }
  
  RadioButtonIcon.propTypes = {
    /**
     * If `true`, the component is checked.
     */
    checked: PropTypes.bool,
    /**
     * Override or extend the styles applied to the component.
     * See [CSS API](#css) below for more details.
     */
    classes: PropTypes.object.isRequired,
  };
  
  export default withStyles(styles, { name: 'PrivateRadioButtonIcon' })(RadioButtonIcon);
  