function handleFocusIndexChange (newIndex, oldIndex) {
    if (newIndex === oldIndex) return;
    if (!getElements().tabs[ newIndex ]) return;
    adjustOffset();
    redirectFocus();
  }
function handleFocusIndexChange (newIndex, oldIndex) {
    if (newIndex === oldIndex) return;
    if (!getElements().tabs[ newIndex ]) return;
    adjustOffset();
    redirectFocus();
  }
function handleFocusIndexChange ( newIndex , oldIndex ) { if ( newIndex === oldIndex ) return ; if ( ! getElements ( ) . tabs [ newIndex ] ) return ; adjustOffset ( ) ; redirectFocus ( ) ; }
Update the UI whenever `ctrl.focusIndex` is updated
@param {number} newIndex
@param {number} oldIndex
Update the UI whenever ctrl . focusIndex is updated
Handle focus index change