ContentLanguageSettingsForm::buildForm

public ContentLanguageSettingsForm::buildForm(array $form, FormStateInterface $form_state)

public function buildForm(array $form, FormStateInterface $form_state) {
  $entity_types = $this->entityManager->getDefinitions();
  $labels = array();
  $default = array();

  $bundles = $this->entityManager->getAllBundleInfo();
  $language_configuration = array();
  foreach ($entity_types as $entity_type_id => $entity_type) {
    if (!$entity_type instanceof ContentEntityTypeInterface || !$entity_type->hasKey('langcode') || !isset($bundles[$entity_type_id])) {
      continue;
    }
    $labels[$entity_type_id] = $entity_type->getLabel() ? : $entity_type_id;
    $default[$entity_type_id] = FALSE;

    // Check whether we have any custom setting.
    foreach ($bundles[$entity_type_id] as $bundle => $bundle_info) {
      $config = ContentLanguageSettings::loadByEntityTypeBundle($entity_type_id, $bundle);
      if (!$config->isDefaultConfiguration()) {
        $default[$entity_type_id] = $entity_type_id;
      }
      $language_configuration[$entity_type_id][$bundle] = $config;
    }
  }

  asort($labels);

  $form = array(
    '#labels' => $labels,
    '#attached' => array(
      'library' => array(
        'language/drupal.language.admin',
      ),
    ),
    '#attributes' => array(
      'class' => 'language-content-settings-form',
    ),
  );

  $form['entity_types'] = array(
    '#title' => $this->t('Custom language settings'),
    '#type' => 'checkboxes',
    '#options' => $labels,
    '#default_value' => $default,
  );

  $form['settings'] = array('#tree' => TRUE);

  foreach ($labels as $entity_type_id => $label) {
    $entity_type = $entity_types[$entity_type_id];

    $form['settings'][$entity_type_id] = array(
      '#title' => $label,
      '#type' => 'container',
      '#entity_type' => $entity_type_id,
      '#theme' => 'language_content_settings_table',
      '#bundle_label' => $entity_type->getBundleLabel() ? : $label,
      '#states' => array(
        'visible' => array(
          ':input[name="entity_types[' . $entity_type_id . ']"]' => array('checked' => TRUE),
        ),
      ),
    );

    foreach ($bundles[$entity_type_id] as $bundle => $bundle_info) {
      $form['settings'][$entity_type_id][$bundle]['settings'] = array(
        '#type' => 'item',
        '#label' => $bundle_info['label'],
        'language' => array(
          '#type' => 'language_configuration',
          '#entity_information' => array(
            'entity_type' => $entity_type_id,
            'bundle' => $bundle,
          ),
          '#default_value' => $language_configuration[$entity_type_id][$bundle],
        ),
      );
    }
  }

  $form['actions']['#type'] = 'actions';
  $form['actions']['submit'] = array(
    '#type' => 'submit',
    '#value' => $this->t('Save configuration'),
    '#button_type' => 'primary',
  );

  return $form;
}