ChangeSortTypeSnippet.java

//somewhere in activity
private void showSortOptionsDialog() {
  ArrayAdapter<String> adapter =
      new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, new String[] {
          "Timestamp", "Category", "Author", "Content"
      });
  new AlertDialog.Builder(this).setAdapter(adapter, new DialogInterface.OnClickListener() {
    @Override public void onClick(DialogInterface dialogInterface, int position) {
      ArticleSortOptionsActivity.this.newSortType = position;
    }
  }).setOnDismissListener(new DialogInterface.OnDismissListener() {
    @Override public void onDismiss(DialogInterface dialogInterface) {
      if (ArticleSortOptionsActivity.this.newSortType
          != ArticleSortOptionsActivity.this.sortType) {
        runOnUiThread(new Runnable() {
          @Override public void run() {
            ArticleSortOptionsActivity.this.sortType =
                ArticleSortOptionsActivity.this.newSortType;
            ArticleSortOptionsActivity.this.dataset.changeSortType(
                ArticleSortOptionsActivity.this.sortType);
          }
        });
      }
    }
  }).show();
}

//somewhere in Dataset
public void changeSortType(int sortType) {
  this.sortType = sortType;
  List<Article> items = new ArrayList<>();
  for (int j = 0; j < sortedList.size(); j++) {
    items.add(sortedList.get(j));
  }
  sortedList.clear();
  sortedList.addAll(items);
  sortedList.endBatchedUpdates();
}