class Reline::LineEditor

def just_move_cursor
  prompt, prompt_width, prompt_list = check_multiline_prompt(@buffer_of_lines)
  move_cursor_up(@started_from)
  new_first_line_started_from =
    if @line_index.zero?
      0
    else
      calculate_height_by_lines(@buffer_of_lines[0..(@line_index - 1)], prompt_list || prompt)
    end
  first_line_diff = new_first_line_started_from - @first_line_started_from
  @cursor, @cursor_max, _, @byte_pointer = calculate_nearest_cursor(@buffer_of_lines[@line_index], @cursor, @started_from, @byte_pointer, false)
  new_started_from = calculate_height_by_width(prompt_width + @cursor) - 1
  calculate_scroll_partial_screen(@highest_in_all, new_first_line_started_from + new_started_from)
  @previous_line_index = nil
  @line = @buffer_of_lines[@line_index]
  if @rerender_all
    rerender_all_lines
    @rerender_all = false
    true
  else
    @first_line_started_from = new_first_line_started_from
    @started_from = new_started_from
    move_cursor_down(first_line_diff + @started_from)
    Reline::IOGate.move_cursor_column((prompt_width + @cursor) % @screen_size.last)
    false
  end
end