1  export function attachScrollHandler(playlistElement, scrollHandler, scrollHandlerAttached) {
 2    if (scrollHandlerAttached || !playlistElement) {
 3      return scrollHandlerAttached;
 4    }
 5  
 6    playlistElement.addEventListener('scroll', scrollHandler);
 7  
 8    scrollHandler();
 9  
10    return true;
11  }
12  
13  export function detachScrollHandler(playlistElement, scrollHandler, scrollHandlerAttached) {
14    if (!scrollHandlerAttached || !playlistElement) {
15      return scrollHandlerAttached;
16    }
17  
18    playlistElement.removeEventListener('scroll', scrollHandler);
19  
20    return false;
21  }