private void onListItemClick(ListView listView, View v, int position) {
    @SuppressWarnings("unchecked")
    T graphObject = (T) listView.getItemAtPosition(position);
    String id = adapter.getIdOfGraphObject(graphObject);
    selectionStrategy.toggleSelection(id);
    adapter.notifyDataSetChanged();

    if (onSelectionChangedListener != null) {
      onSelectionChangedListener.onSelectionChanged(PickerFragment.this);
    }
  }