/**
   * Handle any clicks on {@link ExpandableListAdapter} children, which usually mean toggling its
   * visible state.
   */
  @Override
  public boolean onChildClick(
      ExpandableListView parent, View view, int groupPosition, int childPosition, long id) {
    final CheckBox checkbox = (CheckBox) view.findViewById(android.R.id.checkbox);

    final AccountDisplay account = (AccountDisplay) mAdapter.getGroup(groupPosition);
    final GroupDelta child = (GroupDelta) mAdapter.getChild(groupPosition, childPosition);
    if (child != null) {
      checkbox.toggle();
      child.putVisible(checkbox.isChecked());
    } else {
      // Open context menu for bringing back unsynced
      this.openContextMenu(view);
    }
    return true;
  }