public void setList(@Nullable SortedList<T> list) {
        mList = list;
        notifyDataSetChanged();
    }
A simple adapter which also inserts a header item ".." to handle going up to the parent folder.

@param <T> the type which is used, for example a normal java File object.
android/modules/module_filepicker/src/main/java/com/nononsenseapps/filepicker/FileItemAdapter.java