private void clearResults() {
    if (adapter != null) {
      boolean wasSelection = !selectionStrategy.isEmpty();
      boolean wasData = !adapter.isEmpty();

      loadingStrategy.clearResults();
      selectionStrategy.clear();
      adapter.notifyDataSetChanged();

      // Tell anyone who cares the data and selection has changed, if they have.
      if (wasData && onDataChangedListener != null) {
        onDataChangedListener.onDataChanged(PickerFragment.this);
      }
      if (wasSelection && onSelectionChangedListener != null) {
        onSelectionChangedListener.onSelectionChanged(PickerFragment.this);
      }
    }
  }