private void updateEditButton() {
    if (myEditButton != null) {
      final JdkComboBoxItem selectedItem = getSelectedItem();
      if (selectedItem instanceof ProjectJdkComboBoxItem && myProject != null) {
        myEditButton.setEnabled(ProjectStructureConfigurable.getInstance(myProject).getProjectJdksModel().getProjectSdk() != null);
      }
      else {
        myEditButton.setEnabled(selectedItem != null && selectedItem.getJdk() != null);
      }
    }
  }
private void updateEditButton()