import * as React from 'react' ; import { CircularProgress , Theme } from '@material-ui/core' ; import makeStyles from '@material-ui/core/styles/makeStyles' ; const useStyles = makeStyles ( ( theme ) => ( { root : { display : 'flex' , justifyContent : 'center' , } , loader : { margin : theme . spacing ( 3 ) , } , } ) ) ; const TimelineLoading = ( ) => { const classes = useStyles ( ) ; return ( < div className = { classes . root } > < CircularProgress className = { classes . loader } color = "primary" / > < /div>); } ; export { TimelineLoading } ;