content: import React from 'react';
  import PropTypes from 'prop-types';
  import clsx from 'clsx';
  import withStyles from '../styles/withStyles';
  import ButtonBase from '../ButtonBase';
  import unsupportedProp from '../utils/unsupportedProp';
  
  export const styles = theme => ({
    /* Styles applied to the root element. */
    root: {
      transition: theme.transitions.create(['color', 'padding-top'], {
        duration: theme.transitions.duration.short,
      }),
      padding: '6px 12px 8px',
      minWidth: 80,
      maxWidth: 168,
      color: theme.palette.text.secondary,
      flex: '1',
      '&$iconOnly': {
        paddingTop: 16,
      },
      '&$selected': {
        paddingTop: 6,
        color: theme.palette.primary.main,
      },
    },
    /* Pseudo-class applied to the root element if selected. */
    selected: {},
    /* Pseudo-class applied to the root element if `showLabel={false}` and not selected. */
    iconOnly: {},
    /* Styles applied to the span element that wraps the icon and label. */
    wrapper: {
      display: 'inline-flex',
      alignItems: 'center',
      justifyContent: 'center',
      width: '100%',
      flexDirection: 'column',
    },
    /* Styles applied to the label's span element. */
    label: {
      fontFamily: theme.typography.fontFamily,
      fontSize: theme.typography.pxToRem(12),
      opacity: 1,
      transition: 'font-size 0.2s, opacity 0.2s',
      transitionDelay: '0.1s',
      '&$iconOnly': {
        opacity: 0,
        transitionDelay: '0s',
      },
      '&$selected': {
        fontSize: theme.typography.pxToRem(14),
      },
    },
  });
  
  const BottomNavigationAction = React.forwardRef(function BottomNavigationAction(props, ref) {
    const {
      classes,
      className,
      icon,
      label,
      onChange,
      onClick,
      selected,
      showLabel,
      value,
      ...other
    } = props;
  
    const handleChange = event => {
      if (onChange) {
        onChange(event, value);
      }
  
      if (onClick) {
        onClick(event);
      }
    };
  
    return (
      <ButtonBase
        ref={ref}
        className={clsx(
          classes.root,
          {
            [classes.selected]: selected,
            [classes.iconOnly]: !showLabel && !selected,
          },
          className,
        )}
        focusRipple
        onClick={handleChange}
        {...other}
      >
        <span className={classes.wrapper}>
          {icon}
          <span
            className={clsx(classes.label, {
              [classes.selected]: selected,
              [classes.iconOnly]: !showLabel && !selected,
            })}
          >
            {label}
          </span>
        </span>
      </ButtonBase>
    );
  });
  
  BottomNavigationAction.propTypes = {
    /**
     * This prop isn't supported.
     * Use the `component` prop if you need to change the children structure.
     */
    children: unsupportedProp,
    /**
     * Override or extend the styles applied to the component.
     * See [CSS API](#css) below for more details.
     */
    classes: PropTypes.object.isRequired,
    /**
     * @ignore
     */
    className: PropTypes.string,
    /**
     * The icon element.
     */
    icon: PropTypes.node,
    /**
     * The label element.
     */
    label: PropTypes.node,
    /**
     * @ignore
     */
    onChange: PropTypes.func,
    /**
     * @ignore
     */
    onClick: PropTypes.func,
    /**
     * @ignore
     */
    selected: PropTypes.bool,
    /**
     * If `true`, the `BottomNavigationAction` will show its label.
     * By default, only the selected `BottomNavigationAction`
     * inside `BottomNavigation` will show its label.
     */
    showLabel: PropTypes.bool,
    /**
     * You can provide your own value. Otherwise, we fallback to the child position index.
     */
    value: PropTypes.any,
  };
  
  export default withStyles(styles, { name: 'MuiBottomNavigationAction' })(BottomNavigationAction);
  