The navigator both provides context in a potentially confusing situation and simultaneously provides a direct navigation idiom where a user may move the rectangle to focus on a different part of the song.

• 该导航器不仅为可能产生混乱的情况提供了清晰的情境信息，同时用户也可以拖动它来提供直接的导航操作，移动到歌曲的任何一段上。