@Override
  public void setEnabled(final boolean enabled) {
    if (mainComposite == null) {
      return;
    }

    objects.setEnabled(enabled);
    libraries.setEnabled(enabled);
    librarySearchPath.setEnabled(enabled);
    disablePredefinedExtrnalDirs.setEnabled(enabled);
  }
  @Override
  public void performDefaults() {
    if (mainComposite == null) {
      return;
    }

    objects.setEnabled(true);
    objects.setValues(new String[] {});

    libraries.setEnabled(true);
    libraries.setValues(new String[] {});

    librarySearchPath.setEnabled(true);
    librarySearchPath.setValues(new String[] {});

    disablePredefinedExtrnalDirs.setEnabled(true);
    disablePredefinedExtrnalDirs.setSelection(false);
  }