Move the focus to the next element in the list. If the last element is currently focused, loop to the first element.
Move the focus to the previous element in the list. If the first element is currently focused, loop to the last element.
Possibly delete the element at the focus, then move the element on the
left to the focus. If no element is on the left, focus on the element to
the right. If the deletion will cause the list to be empty, return