PreferencesFragment.java 文件源码

private void disableLastCheckedPref() {
  Collection<CheckBoxPreference> checked = new ArrayList<CheckBoxPreference>(3);
  if (decode1D.isChecked()) {
    checked.add(decode1D);
  }
  if (decodeQR.isChecked()) {
    checked.add(decodeQR);
  }
  if (decodeDataMatrix.isChecked()) {
    checked.add(decodeDataMatrix);
  }
  boolean disable = checked.size() < 2;
  CheckBoxPreference[] checkBoxPreferences = {decode1D, decodeQR, decodeDataMatrix};
  for (CheckBoxPreference pref : checkBoxPreferences) {
    pref.setEnabled(!(disable && checked.contains(pref)));
  }
}