/**
   * We handle radio button selections by enabling and disabling various controls. There are only
   * two sources of these events that we care about.
   */
  @Override
  protected void radioButtonSelected(Object source) {
    if (source == existingApplicationRadioButton || source == createNewApplicationRadioButton) {
      boolean isCreatingNewApplication =
          (Boolean) createNewApplicationRadioButtonObservable.getValue();

      existingApplicationCombo.setEnabled(!isCreatingNewApplication);
      newApplicationNameText.setEnabled(isCreatingNewApplication);
      newApplicationDescriptionText.setEnabled(isCreatingNewApplication);
    }
  }