def find(str)
      index = items.index {|i| i.index > current_row && i.name.start_with?(str)} || items.index {|i| i.name.start_with? str}
      move_cursor index if index
    end
def find(str)
      index = items.index {|i| i.index > current_row && i.name.start_with?(str)} || items.index {|i| i.name.start_with? str}
      move_cursor index if index
    end
Focus at the first file or directory of which name starts with the given String.