function setActive(direct) {
    /*
      Gets all of the song container elements.
    */
    var songContainers = document.getElementsByClassName("amplitude-song-container");

    /*
    Removes all of the active song containrs.
    */
    for (var i = 0; i < songContainers.length; i++) {
      songContainers[i].classList.remove("amplitude-active-song-container");
    }

    /*
    Finds the active index and adds the active song container to the element
    that represents the song at the index.
    */
    if (_config2.default.active_playlist == "" || _config2.default.active_playlist == null) {
      var activeIndex = "";

      /*
        If we click directly on the song element, we ignore
        whether it's in shuffle or not.
      */
      if (direct) {
        activeIndex = _config2.default.active_index;
      } else {
        if (_config2.default.shuffle_on) {
          activeIndex = _config2.default.shuffle_list[_config2.default.active_index].index;
        } else {
          activeIndex = _config2.default.active_index;
        }
      }

      if (document.querySelectorAll('.amplitude-song-container[data-amplitude-song-index="' + activeIndex + '"]')) {
        var _songContainers = document.querySelectorAll('.amplitude-song-container[data-amplitude-song-index="' + activeIndex + '"]');

        for (var _i = 0; _i < _songContainers.length; _i++) {
          if (!_songContainers[_i].hasAttribute("data-amplitude-playlist")) {
            _songContainers[_i].classList.add("amplitude-active-song-container");
          }
        }
      }
    } else {
      /*
        If we have an active playlist or the action took place directly on the
        song element, we ignore the shuffle.
      */
      if (_config2.default.active_playlist != null && _config2.default.active_playlist != "" || direct) {
        var activePlaylistIndex = _config2.default.playlists[_config2.default.active_playlist].active_index;
      } else {
        var activePlaylistIndex = "";

        if (_config2.default.playlists[_config2.default.active_playlist].shuffle) {
          activePlaylistIndex = _config2.default.playlists[_config2.default.active_playlist].shuffle_list[_config2.default.playlists[_config2.default.active_playlist].active_index].index;
        } else {
          activePlaylistIndex = _config2.default.playlists[_config2.default.active_playlist].active_index;
        }
      }

      if (document.querySelectorAll('.amplitude-song-container[data-amplitude-song-index="' + activePlaylistIndex + '"][data-amplitude-playlist="' + _config2.default.active_playlist + '"]')) {
        var _songContainers2 = document.querySelectorAll('.amplitude-song-container[data-amplitude-song-index="' + activePlaylistIndex + '"][data-amplitude-playlist="' + _config2.default.active_playlist + '"]');

        for (var _i2 = 0; _i2 < _songContainers2.length; _i2++) {
          _songContainers2[_i2].classList.add("amplitude-active-song-container");
        }
      }
    }
  }
Applies the class 'amplitude-active-song-container' to the element
containing visual information regarding the active song.

@prop {boolean} direct - Determines if it was a direct click on the song. We
then don't care if shuffle is on or not.

@access public