public void processChecked() {
   try {
     Value value = getMapValue(_keys, CHECKED);
     if (!value.isNull() && value.getString().equals("true")) {
       _isChecked = true;
     } else _isChecked = false;
   } catch (Exception e) {
     throw new EvaluateException("Invalid attribute for check-box");
   }
 }
  public void processCheckChangedListener() {
    Value listener = getMapValue(_keys, CHECK_CHECKED_LISTENER);
    if (!listener.isNull() && listener.isString()) {
      final String base = listener.getString();
      _changeListener =
          new CompoundButton.OnCheckedChangeListener() {

            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
              String total =
                  String.format("(let ((is-checked %1$s)) %2$s)", (isChecked) ? "1" : "F", base);
              _lispInterpreter.evaluateExpression(total, true);
            }
          };
    }
    if (encapsulated != null)
      ((CompoundButton) encapsulated).setOnCheckedChangeListener(_changeListener);
  }