function handleFocus(evt) {
    if (evt.type === 'focusin') {
      addClass(evt.target, 'focus');
    } else if (evt.type === 'focusout') {
      removeClass(evt.target, 'focus');
    }
  } // Helper functons to minimize runtime memory footprint when lots of buttons on page
// Focus handler for toggle buttons.  Needs class of 'focus' when focused.
Focus handler for toggle buttons.  Needs class of 'focus' when focused.
Focus handler for toggle buttons . Needs class of ' focus ' when focused .
function handleFocus(evt) {
    if (evt.type === 'focusin') {
      addClass(evt.target, 'focus');
    } else if (evt.type === 'focusout') {
      removeClass(evt.target, 'focus');
    }
  } 
function handleFocus ( evt ) { if ( evt . type === 'focusin' ) { addClass ( evt . target , 'focus' ) ; } else if ( evt . type === 'focusout' ) { removeClass ( evt . target , 'focus' ) ; } }
Focus handler for toggle buttons.
Focus handler for toggle buttons .
// Helper functons to minimize runtime memory footprint when lots of buttons on page