@Override
 protected void onResume() {
   super.onResume();
   back_btn.setVisibility(ImageButton.VISIBLE);
   TextView top_title_tv = (TextView) this.getParent().findViewById(R.id.top_title);
   top_title_tv.setText(R.string.menu_local_music);
   adapter.notifyDataSetChanged();
 }
 @Override
 protected Set<Integer> getPopUpMenu() {
   if (adapter.getCheckedBoxPositionIds().size() > 0) {
     popUpMenu.add(PopupMenu.ADD_TO.getMenu());
   } else {
     popUpMenu.remove(PopupMenu.ADD_TO.getMenu());
   }
   return popUpMenu;
 }