Issue #3037204 by starlight-sparkle, atowl, dww, kim.pepper: If upload...

use Drupal\Core\Render\Element;

use Drupal\Core\Render\ElementInfoManagerInterface;

use Drupal\Core\StringTranslation\TranslatableMarkup;

use Drupal\Core\Url;

use Drupal\file\Element\ManagedFile;

use Drupal\file\Entity\File;

use Symfony\Component\DependencyInjection\ContainerInterface;

   * {@inheritdoc}

   */

  public function settingsForm(array $form, FormStateInterface $form_state) {

    $element['notice'] = [

      '#type' => 'container',

      '#markup' => $this->t('The UploadProgress PHP extension must be enabled to configure the progress indicator. Check the <a href=":status">status report</a> for more information.', [':status' => Url::fromRoute('system.status')->toString()]),

      '#weight' => 16,

      '#access' => !extension_loaded('uploadprogress'),

      '#attributes' => [

        'role' => 'status',

      ],

    ];

    $element['progress_indicator'] = [

      '#type' => 'radios',

      '#title' => $this->t('Progress indicator'),

      '#default_value' => $this->getSetting('progress_indicator'),

      '#description' => $this->t('The throbber display does not show the status of uploads but takes up less space. The progress bar is helpful for monitoring progress on large uploads.'),

      '#weight' => 16,

      '#access' => extension_loaded('uploadprogress'),

      '#disabled' => !extension_loaded('uploadprogress'),

    ];

    return $element;

  }