drupal/core/themes/claro/claro.theme

<?php

/**
 * @file
 * Functions to support theming in the Claro theme.
 */

use Drupal\claro\ClaroPreRender;
use Drupal\Component\Utility\Html;
use Drupal\Component\Utility\NestedArray;
use Drupal\Component\Utility\UrlHelper;
use Drupal\Core\Entity\EntityForm;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Link;
use Drupal\Core\Render\Element;
use Drupal\Core\Template\Attribute;
use Drupal\Core\Url;
use Drupal\media\MediaForm;
use Drupal\file\FileInterface;
use Drupal\views\Form\ViewsForm;
use Drupal\views\ViewExecutable;
use Drupal\views_ui\Form\Ajax\ViewsFormInterface;

/**
 * Implements hook_theme_suggestions_HOOK_alter() for form_element.
 */
function claro_theme_suggestions_form_element_alter(&$suggestions, $variables) {
  if (!empty($variables['element']['#type'])) {
    $suggestions[] = 'form_element__' . $variables['element']['#type'];
  }
}

/**
 * Implements hook_theme_suggestions_HOOK_alter() for details.
 */
function claro_theme_suggestions_details_alter(&$suggestions, $variables) {
  if (!empty($variables['element']['#vertical_tab_item'])) {
    $suggestions[] = 'details__vertical_tabs';
  }
}

/**
 * Implements hook_preprocess_HOOK() for menu-local-tasks templates.
 *
 * Use preprocess hook to set #attached to child elements because they will be
 * processed by Twig and \Drupal::service('renderer')->render() will be invoked.
 */
function claro_preprocess_menu_local_tasks(&$variables) {
  if (!empty($variables['primary'])) {
    $variables['primary']['#attached'] = [
      'library' => [
        'claro/drupal.nav-tabs',
      ],
    ];
  }
  elseif (!empty($variables['secondary'])) {
    $variables['secondary']['#attached'] = [
      'library' => [
        'claro/drupal.nav-tabs',
      ],
    ];
  }

  foreach (Element::children($variables['primary']) as $key) {
    $variables['primary'][$key]['#level'] = 'primary';
  }
  foreach (Element::children($variables['secondary']) as $key) {
    $variables['secondary'][$key]['#level'] = 'secondary';
  }
}

/**
 * Implements hook_preprocess_HOOK() for menu-local-task templates.
 */
function claro_preprocess_menu_local_task(&$variables) {
  $variables['link']['#options']['attributes']['class'][] = 'tabs__link';
  $variables['link']['#options']['attributes']['class'][] = 'js-tabs-link';

  // Ensure is-active class is set when the tab is active. The generic active
  // link handler applies stricter comparison rules than what is necessary for
  // tabs.
  if (isset($variables['is_active']) && $variables['is_active'] === TRUE) {
    $variables['link']['#options']['attributes']['class'][] = 'is-active';
  }

  if (isset($variables['element']['#level'])) {
    $variables['level'] = $variables['element']['#level'];
  }
}

/**
 * Implements hook_preprocess_HOOK() for menu-local-task Views UI templates.
 */
function claro_preprocess_menu_local_task__views_ui(&$variables) {
  // Remove 'tabs__link' without adding a new class because it couldn't be used
  // reliably.
  // @see https://www.drupal.org/node/3051605
  $link_class_index = array_search('tabs__link', $variables['link']['#options']['attributes']['class']);
  if ($link_class_index !== FALSE) {
    unset($variables['link']['#options']['attributes']['class'][$link_class_index]);
  }
}

/**
 * Implements template_preprocess_HOOK() for node_add_list.
 *
 * Makes node_add_list variables compatible with entity_add_list.
 */
function claro_preprocess_node_add_list(&$variables) {
  if (!empty($variables['content'])) {
    /** @var \Drupal\node\NodeTypeInterface $type */
    foreach ($variables['content'] as $type) {
      $label = $type->label();
      $description = $type->getDescription();
      $type_id = $type->id();
      $add_url = Url::fromRoute('node.add', ['node_type' => $type_id]);
      $variables['bundles'][$type_id] = [
        'label' => $label,
        'add_link' => Link::fromTextAndUrl($label, $add_url),
        'description' => [],
      ];
      if (!empty($description)) {
        $variables['bundles'][$type_id]['description'] = [
          '#markup' => $description,
        ];
      }
    }
    $variables['attributes']['class'][] = 'node-type-list';
  }
}

/**
 * Implements template_preprocess_HOOK() for block_content_add_list.
 *
 * Makes block_content_add_list variables compatible with entity_add_list.
 */
function claro_preprocess_block_content_add_list(&$variables) {
  if (!empty($variables['content'])) {
    $query = \Drupal::request()->query->all();
    /** @var \Drupal\block_content\BlockContentTypeInterface $type */
    foreach ($variables['content'] as $type) {
      $label = $type->label();
      $description = $type->getDescription();
      $type_id = $type->id();
      $add_url = Url::fromRoute('block_content.add_form', [
        'block_content_type' => $type_id,
      ], [
        'query' => $query,
      ]);
      $variables['bundles'][$type_id] = [
        'label' => $label,
        'add_link' => Link::fromTextAndUrl($label, $add_url),
        'description' => [],
      ];

      if (!empty($description)) {
        $variables['bundles'][$type_id]['description'] = [
          '#markup' => $description,
        ];
      }
    }
  }
}

/**
 * Implements template_preprocess_HOOK() for entity_add_list.
 */
function claro_preprocess_entity_add_list(&$variables) {
  // Remove description if empty.
  foreach ($variables['bundles'] as $type_id => $values) {
    if (isset($values['description']['#markup']) && empty($values['description']['#markup'])) {
      $variables['bundles'][$type_id]['description'] = [];
    }
  }
}

/**
 * Implements hook_preprocess_block() for block content.
 *
 * Disables contextual links for all blocks except for layout builder blocks.
 */
function claro_preprocess_block(&$variables) {
  if (isset($variables['title_suffix']['contextual_links']) && !isset($variables['elements']['#contextual_links']['layout_builder_block'])) {
    unset($variables['title_suffix']['contextual_links']);
    unset($variables['elements']['#contextual_links']);

    $variables['attributes']['class'] = array_diff($variables['attributes']['class'], ['contextual-region']);
  }
}

/**
 * Implements template_preprocess_HOOK() for admin_block.
 */
function claro_preprocess_admin_block(&$variables) {
  if (!empty($variables['block']['content'])) {
    $variables['block']['content']['#attributes']['class'][] = 'admin-list--panel';
  }
}

/**
 * Implements template_preprocess_HOOK() for admin_block.
 */
function claro_preprocess_admin_block_content(&$variables) {
  foreach ($variables['content'] as &$item) {
    $link_attributes = $item['url']->getOption('attributes') ?: [];
    $link_attributes['class'][] = 'admin-item__link';
    $item['url']->setOption('attributes', $link_attributes);
    $item['link'] = Link::fromTextAndUrl($item['title'], $item['url']);

    if (empty($item['description']) || empty($item['description']['#markup'])) {
      unset($item['description']);
    }
  }
}

/**
 * Implements hook_preprocess_HOOK() for menu-local-action templates.
 */
function claro_preprocess_menu_local_action(array &$variables) {
  $variables['link']['#options']['attributes']['class'][] = 'button--primary';
  $variables['attributes']['class'][] = 'local-actions__item';
  $legacy_class_key = array_search('button-action', $variables['link']['#options']['attributes']['class']);

  if ($legacy_class_key !== FALSE) {
    $variables['link']['#options']['attributes']['class'][$legacy_class_key] = 'button--action';
  }
}

/**
 * Implements hook_element_info_alter().
 */
function claro_element_info_alter(&$type) {
  // Add a pre-render function that handles the sidebar of the node form.
  // @todo Refactor when https://www.drupal.org/node/3056089 is in.
  if (isset($type['container'])) {
    $container_pre_renders = !empty($type['container']['#pre_render']) ? $type['container']['#pre_render'] : [];
    array_unshift($container_pre_renders, [ClaroPreRender::class, 'container']);

    $type['container']['#pre_render'] = $container_pre_renders;
  }

  // @todo Refactor when https://www.drupal.org/node/3016343 is fixed.
  if (isset($type['text_format'])) {
    $type['text_format']['#pre_render'][] = [ClaroPreRender::class, 'textFormat'];
  }

  // Add a pre-render function for Operations to set #dropbutton_type.
  if (isset($type['operations'])) {
    // In Claro, Operations should always use the extrasmall dropbutton variant.
    // To add CSS classes based on variants, the element must have the
    // #dropbutton_type property before it is processed by
    // \Drupal\Core\Render\Element\Dropbutton::preRenderDropbutton(). This
    // ensures #dropbutton_type is available to preRenderDropbutton().
    $operations_pre_renders = !empty($type['operations']['#pre_render']) ? $type['operations']['#pre_render'] : [];
    array_unshift($operations_pre_renders, [ClaroPreRender::class, 'operations']);

    $type['operations']['#pre_render'] = $operations_pre_renders;
  }

  if (isset($type['vertical_tabs'])) {
    $type['vertical_tabs']['#pre_render'][] = [ClaroPreRender::class, 'verticalTabs'];
  }

  // Add a pre-render to managed_file.
  if (isset($type['managed_file'])) {
    $type['managed_file']['#pre_render'][] = [ClaroPreRender::class, 'managedFile'];
  }

  // Add a pre-render to status_messages to alter the placeholder markup.
  if (isset($type['status_messages'])) {
    $type['status_messages']['#pre_render'][] = [ClaroPreRender::class, 'messagePlaceholder'];
  }
}

/**
 * Implements template_preprocess_filter_guidelines().
 */
function claro_preprocess_filter_guidelines(&$variables) {
  // Fix filter guidelines selector issue of 'filter/drupal.filter'.
  // @todo Remove when https://www.drupal.org/node/2881212 is fixed.
  $variables['attributes']['class'][] = 'filter-guidelines-item';
  $variables['attributes']['class'][] = 'filter-guidelines-' . $variables['format']->id();
}

/**
 * Implements template_preprocess_text_format_wrapper().
 *
 * @todo Remove when https://www.drupal.org/node/3016343 is fixed.
 */
function claro_preprocess_text_format_wrapper(&$variables) {
  $description_attributes = [];
  if (!empty($variables['attributes']['id'])) {
    $description_attributes['id'] = $variables['attributes']['aria-describedby'] = $variables['attributes']['id'];
    unset($variables['attributes']['id']);
  }
  $variables['description_attributes'] = new Attribute($description_attributes);
}

/**
 * Implements hook_theme_registry_alter().
 */
function claro_theme_registry_alter(&$theme_registry) {
  if (!empty($theme_registry['admin_block_content'])) {
    $theme_registry['admin_block_content']['variables']['attributes'] = [];
  }

  // @todo Remove when https://www.drupal.org/node/3016346 is fixed.
  if (!empty($theme_registry['text_format_wrapper'])) {
    $theme_registry['text_format_wrapper']['variables']['disabled'] = FALSE;
  }
}

/**
 * Implements hook_preprocess_install_page().
 */
function claro_preprocess_install_page(&$variables) {
  // Claro has custom styling for the install page.
  $variables['#attached']['library'][] = 'claro/install-page';
}

/**
 * Implements hook_preprocess_maintenance_page().
 */
function claro_preprocess_maintenance_page(&$variables) {
  // Claro has custom styling for the maintenance page.
  $variables['#attached']['library'][] = 'claro/maintenance-page';
}

/**
 * Implements hook_theme_suggestions_maintenance_page_alter().
 */
function claro_theme_suggestions_maintenance_page_alter(&$suggestions) {
  try {
    $is_front = \Drupal::service('path.matcher')->isFrontPage();
  }
  catch (Exception $e) {
    // An exception could mean that the database is offline. This scenario
    // should also be rendered using the frontpage template.
    $is_front = TRUE;
  }

  if ($is_front) {
    // Add theme suggestion for maintenance page rendered as front page. This
    // allows separating different applications such as update.php from the
    // actual maintenance page.
    $suggestions[] = 'maintenance_page__front';
  }
}

/**
 * Implements hook_preprocess_HOOK() for details.
 *
 * @todo Revisit when https://www.drupal.org/node/3056089 is in.
 */
function claro_preprocess_details(&$variables) {
  $element = $variables['element'];

  if (!empty($element['#accordion_item'])) {
    // Details should appear as an accordion item.
    $variables['accordion_item'] = TRUE;
  }

  if (!empty($element['#accordion'])) {
    // Details should appear as a standalone accordion.
    $variables['accordion'] = TRUE;
  }

  if (!empty($element['#theme']) &&  $element['#theme'] === 'file_widget_multiple') {
    // Mark the details required if needed. If the file widget allows uploading
    // multiple files, the required state is checked by checking the state of
    // the first child.
    $variables['required'] = $element[0]['#required'] ?? !empty($element['#required']);

    // If the error is the same as the one in the multiple field widget element,
    // we have to avoid displaying it twice. Stark has this issue as well.
    // @todo revisit when https://www.drupal.org/node/3084906 is fixed.
    if (isset($element['#errors']) && isset($variables['errors']) && $element['#errors'] === $variables['errors']) {
      unset($variables['errors']);
    }
  }

  $variables['disabled'] = !empty($element['#disabled']);
}

/**
 * Implements hook_form_alter().
 */
function claro_form_alter(array &$form, FormStateInterface $form_state, $form_id) {
  $build_info = $form_state->getBuildInfo();
  $form_object = $form_state->getFormObject();

  // Make entity forms delete link use the action-link component.
  if (isset($form['actions']['delete']['#type']) && $form['actions']['delete']['#type'] === 'link' && !empty($build_info['callback_object']) && $build_info['callback_object'] instanceof EntityForm) {
    $form['actions']['delete'] = _claro_convert_link_to_action_link($form['actions']['delete'], 'trash', 'default', 'danger');
  }

  if (($form_object instanceof ViewsForm || $form_object instanceof ViewsFormInterface) && isset($form['override']['#prefix'])) {
    // Replace form--inline class so positioning of override form elements don't
    // have to depend on floats.
    $form['override']['#prefix'] = str_replace('form--inline', 'form--flex', $form['override']['#prefix']);
  }

  if ($form_object instanceof ViewsForm && strpos($form_object->getBaseFormId(), 'views_form_media_library') === 0) {
    if (isset($form['header'])) {
      $form['header']['#attributes']['class'][] = 'media-library-views-form__header';
      $form['header']['media_bulk_form']['#attributes']['class'][] = 'media-library-views-form__bulk_form';
    }
    $form['actions']['submit']['#attributes']['class'] = ['media-library-select'];
    $form['#attributes']['class'][] = 'media-library-views-form';
  }

  if ($form_object instanceof ViewsForm && !empty($form['header'])) {
    $view = $form_state->getBuildInfo()['args'][0];
    $view_title = $view->getTitle();

    // Determine if the Views form includes a bulk operations form. If it does,
    // move it to the bottom and remove the second bulk operations submit.
    foreach (Element::children($form['header']) as $key) {
      if (strpos($key, '_bulk_form') !== FALSE) {
        // Move the bulk actions form from the header to its own container.
        $form['bulk_actions_container'] = $form['header'][$key];
        unset($form['header'][$key]);

        // Remove the supplementary bulk operations submit button as it appears
        // in the same location the form was moved to.
        unset($form['actions']);

        $form['bulk_actions_container']['#attributes']['data-drupal-views-bulk-actions'] = '';
        $form['bulk_actions_container']['#attributes']['class'][] = 'views-bulk-actions';
        $form['bulk_actions_container']['actions']['submit']['#button_type'] = 'primary';
        $form['bulk_actions_container']['actions']['submit']['#attributes']['class'][] = 'button--small';
        $label = t('Perform actions on the selected items in the %view_title view', ['%view_title' => $view_title]);
        $label_id = $key . '_group_label';

        // Group the bulk actions select and submit elements, and add a label
        // that makes the purpose of these elements more clear to
        // screenreaders.
        $form['bulk_actions_container']['#attributes']['role'] = 'group';
        $form['bulk_actions_container']['#attributes']['aria-labelledby'] = $label_id;
        $form['bulk_actions_container']['group_label'] = [
          '#type' => 'container',
          '#markup' => $label,
          '#attributes' => [
            'id' => $label_id,
            'class' => ['visually-hidden'],
          ],
          '#weight' => -1,
        ];

        // Add a status label for counting the number of items selected.
        $form['bulk_actions_container']['status'] = [
          '#type' => 'container',
          '#markup' => t('No items selected'),
          '#weight' => -1,
          '#attributes' => [
            'class' => [
              'js-views-bulk-actions-status',
              'views-bulk-actions__item',
              'views-bulk-actions__item--status',
              'js-show',
            ],
            'data-drupal-views-bulk-actions-status' => '',
          ],
        ];

        // Loop through bulk actions items and add the needed CSS classes.
        $bulk_action_item_keys = Element::children($form['bulk_actions_container'], TRUE);
        $bulk_last_key = NULL;
        $bulk_child_before_actions_key = NULL;
        foreach ($bulk_action_item_keys as $bulk_action_item_key) {
          if (!empty($form['bulk_actions_container'][$bulk_action_item_key]['#type'])) {
            if ($form['bulk_actions_container'][$bulk_action_item_key]['#type'] === 'actions') {
              // We need the key of the element that precedes the actions
              // element.
              $bulk_child_before_actions_key = $bulk_last_key;
              $form['bulk_actions_container'][$bulk_action_item_key]['#attributes']['class'][] = 'views-bulk-actions__item';
            }

            if (!in_array($form['bulk_actions_container'][$bulk_action_item_key]['#type'], ['hidden', 'actions'])) {
              $form['bulk_actions_container'][$bulk_action_item_key]['#wrapper_attributes']['class'][] = 'views-bulk-actions__item';
              $bulk_last_key = $bulk_action_item_key;
            }
          }
        }

        if ($bulk_child_before_actions_key) {
          $form['bulk_actions_container'][$bulk_child_before_actions_key]['#wrapper_attributes']['class'][] = 'views-bulk-actions__item--preceding-actions';
        }
      }
    }
  }
}

/**
 * Implements hook_preprocess_HOOK() for links.
 */
function claro_preprocess_links(&$variables) {
  foreach ($variables['links'] as $links_item) {
    if (!empty($links_item['link']) && !empty($links_item['link']['#url']) && $links_item['link']['#url'] instanceof Url) {
      if ($links_item['link']['#url']->isRouted()) {
        switch ($links_item['link']['#url']->getRouteName()) {
          case 'system.theme_settings_theme':
            $links_item['link'] = _claro_convert_link_to_action_link($links_item['link'], 'cog', 'small');
            break;

          case 'system.theme_uninstall':
            $links_item['link'] = _claro_convert_link_to_action_link($links_item['link'], 'ex', 'small');
            break;

          case 'system.theme_set_default':
            $links_item['link'] = _claro_convert_link_to_action_link($links_item['link'], 'checkmark', 'small');
            break;

          case 'system.theme_install':
            $links_item['link'] = _claro_convert_link_to_action_link($links_item['link'], 'plus', 'small');
            break;

        }
      }
    }
  }

  // This makes it so array keys of #links items are added as a class. This
  // functionality was removed in Drupal 8.1, but still necessary in some
  // instances.
  // @todo remove in https://drupal.org/node/3120962
  if (!empty($variables['links'])) {
    foreach ($variables['links'] as $key => $value) {
      if (!is_numeric($key)) {
        $class = Html::getClass($key);
        $variables['links'][$key]['attributes']->addClass($class);
      }
    }
  }
}

/**
 * Converts a link render element to an action link.
 *
 * This helper merges every attributes from $link['#attributes'], from
 * $link['#options']['attributes'] and from the Url object's.
 *
 * @param array $link
 *   Link renderable array.
 * @param string|null $icon_name
 *   The name of the needed icon. When specified, a CSS class will be added with
 *   the following pattern: 'action-link--icon-[icon_name]'. If the needed icon
 *   is not implemented in CSS, no icon will be added.
 *   Currently available icons are:
 *    - checkmark,
 *    - cog,
 *    - ex,
 *    - plus,
 *    - trash.
 * @param string $size
 *   Name of the small action link variant. Defaults to 'default'.
 *   Supported sizes are:
 *    - default,
 *    - small,
 *    - extrasmall.
 * @param string $variant
 *   Variant of the action link. Supported variants are 'default' and 'danger'.
 *   Defaults to 'default'.
 *
 * @return array
 *   The link renderable converted to action link.
 */
function _claro_convert_link_to_action_link(array $link, $icon_name = NULL, $size = 'default', $variant = 'default') {
  // Early opt-out if we cannot do anything.
  if (empty($link['#type']) || $link['#type'] !== 'link' || empty($link['#url'])) {
    return $link;
  }

  // \Drupal\Core\Render\Element\Link::preRenderLink adds $link['#attributes']
  // to $link[#options]['attributes'] if it is not empty, but it does not merges
  // the 'class' subkey deeply.
  // Because of this, when $link[#options]['attributes']['class'] is set, the
  // classes defined in $link['#attributes']['class'] are ignored.
  //
  // To keep this behavior we repeat this for action-link, which means that this
  // conversion happens a bit earlier. We unset $link['#attributes'] to prevent
  // Link::preRenderLink() doing the same, because for action-links, that would
  // be needless.
  $link += ['#options' => []];
  if (isset($link['#attributes'])) {
    $link['#options'] += [
      'attributes' => [],
    ];
    $link['#options']['attributes'] += $link['#attributes'];
    unset($link['#attributes']);
  }
  $link['#options'] += ['attributes' => []];
  $link['#options']['attributes'] += ['class' => []];

  // Determine the needed (type) variant.
  $variants_supported = ['default', 'danger'];
  $variant = is_string($variant) && in_array($variant, $variants_supported) ? $variant : reset($variants_supported);

  // Remove button, button modifier CSS classes and other unwanted ones.
  $link['#options']['attributes']['class'] = array_diff($link['#options']['attributes']['class'], [
    'button',
    'button--action',
    'button--primary',
    'button--danger',
    'button--small',
    'button--extrasmall',
    'link',
  ]);

  // Adding the needed CSS classes.
  $link['#options']['attributes']['class'][] = 'action-link';

  // Add the variant-modifier CSS class only if the variant is not the default.
  if ($variant !== reset($variants_supported)) {
    $link['#options']['attributes']['class'][] = Html::getClass("action-link--$variant");
  }

  // Add the icon modifier CSS class.
  if (!empty($icon_name)) {
    $link['#options']['attributes']['class'][] = Html::getClass("action-link--icon-$icon_name");
  }

  if ($size && in_array($size, ['small', 'extrasmall'])) {
    $link['#options']['attributes']['class'][] = Html::getClass("action-link--$size");
  }

  // If the provided $link is an item of the 'links' theme function, then only
  // the attributes of the Url object are processed during rendering.
  $url_attributes = $link['#url']->getOption('attributes') ?: [];
  $url_attributes = NestedArray::mergeDeep($url_attributes, $link['#options']['attributes']);
  $link['#url']->setOption('attributes', $url_attributes);

  return $link;
}

/**
 * Implements hook_form_BASE_FORM_ID_alter() for \Drupal\node\NodeForm.
 *
 * Changes vertical tabs to container.
 */
function claro_form_node_form_alter(&$form, FormStateInterface $form_state) {
  $form['#theme'] = ['node_edit_form'];
  $form['#attached']['library'][] = 'claro/node-form';

  $form['advanced']['#type'] = 'container';
  $form['advanced']['#accordion'] = TRUE;
  $form['meta']['#type'] = 'container';
  $form['meta']['#access'] = TRUE;

  $form['revision_information']['#type'] = 'container';
  $form['revision_information']['#group'] = 'meta';
  $form['revision_information']['#attributes']['class'][] = 'entity-meta__revision';
}

/**
 * Implements hook_form_BASE_FORM_ID_alter() for \Drupal\media\MediaForm.
 */
function claro_form_media_form_alter(&$form, FormStateInterface $form_state) {
  // Only attach CSS from core if this form comes from Media core, and not from
  // the contrib Media Entity 1.x branch.
  if (\Drupal::moduleHandler()->moduleExists('media') && $form_state->getFormObject() instanceof MediaForm) {
    // @todo Revisit after https://www.drupal.org/node/2892304 is in. It
    // introduces a footer region to these forms which will allow for us to
    // display a top border over the published checkbox by defining a
    // media-edit-form.html.twig template the same way node does.
    $form['#attached']['library'][] = 'claro/media-form';
  }
}

/**
 * Implements hook_views_ui_display_top_alter().
 */
function claro_views_ui_display_top_alter(&$element) {
  // @todo remove this after https://www.drupal.org/node/3051605 has been
  //   solved.
  $element['tabs']['#prefix'] = preg_replace('/(class="(.+\s)?)tabs(\s.+"|")/', '$1views-tabs$3', $element['tabs']['#prefix']);
  $element['tabs']['#prefix'] = preg_replace('/(class="(.+\s)?)secondary(\s.+"|")/', '$1views-tabs--secondary$3', $element['tabs']['#prefix']);

  foreach (Element::children($element['tabs']) as $tab) {
    $element['tabs'][$tab]['#theme'] = 'menu_local_task__views_ui';
  }

  // Change top extra actions to use the small dropbutton variant.
  // @todo Revisit after https://www.drupal.org/node/3057581 is added.
  if (!empty($element['extra_actions'])) {
    $element['extra_actions']['#dropbutton_type'] = 'small';
  }

  // Add a class to each item in the add display dropdown so they can be styled
  // with a single selector.
  if (isset($element['add_display'])) {
    foreach ($element['add_display'] as &$display_item) {
      if (isset($display_item['#type']) && in_array($display_item['#type'], ['submit', 'button'], TRUE)) {
        $display_item['#attributes']['class'][] = 'views-tabs__action-list-button';
      }
    }
  }

  // Rearrange top bar contents so floats aren't necessary for positioning.
  if (isset($element['extra_actions'], $element['tabs'], $element['add_display'])) {
    $element['extra_actions']['#weight'] = 10;
    $element['extra_actions']['#theme_wrappers'] = [
      'container' => [
        '#attributes' => [
          'class' => ['views-display-top__extra-actions-wrapper'],
        ],
      ],
    ];

    $element['#attributes']['class'] = array_diff($element['#attributes']['class'], ['clearfix']);
  }

}

/**
 * Implements hook_views_ui_display_tab_alter().
 */
function claro_views_ui_display_tab_alter(&$element) {
  // We process the dropbutton-like element on views edit form's
  // display settings top section.
  //
  // That element should be a regular Dropbutton.
  //
  // After that the reported issue is fixed and the element is rendered with
  // the Dropbutton type, we just have to set it's '#dropbutton_type' to
  // 'extrasmall'.
  //
  // @todo: revisit after https://www.drupal.org/node/3057577 is fixed.
  $dummy_dropbutton = &$element['details']['top']['actions'];

  if ($dummy_dropbutton) {
    $child_keys = Element::children($dummy_dropbutton);
    $prefix_regex = '/(<.*class\s*= *["\']?)([^"\']*)(.*)/i';
    $child_count = 0;

    foreach ($child_keys as $key) {
      if (in_array($key, ['prefix', 'suffix'])) {
        continue;
      }
      $nested_child_keys = Element::children($dummy_dropbutton[$key], TRUE);

      if (!empty($nested_child_keys)) {
        foreach ($nested_child_keys as $nested_key) {
          $child_count++;
          $prefix = $dummy_dropbutton[$key][$nested_key]['#prefix'];
          $dummy_dropbutton[$key][$nested_key]['#prefix'] = preg_replace($prefix_regex, '$1$2 dropbutton__item$3', $prefix);
        }
      }
      else {
        $child_count++;
        $prefix = $dummy_dropbutton[$key]['#prefix'];
        $dummy_dropbutton[$key]['#prefix'] = preg_replace($prefix_regex, '$1$2 dropbutton__item$3', $prefix);
      }
    }

    if (!empty($dummy_dropbutton['prefix']) && !empty($dummy_dropbutton['prefix']['#markup'])) {
      $classes = 'dropbutton--extrasmall ';
      $classes .= ($child_count > 1) ? 'dropbutton--multiple' : 'dropbutton--single';
      $prefix = $dummy_dropbutton['prefix']['#markup'];
      $dummy_dropbutton['prefix']['#markup'] = preg_replace($prefix_regex, '$1$2 ' . $classes . '$3', $prefix);
    }
  }

  // If the top details have both actions and title, the `actions` weights need
  // to be adjusted so the DOM order matches the order of appearance.
  if (isset($element['details']['top']['actions'], $element['details']['top']['display_title'])) {
    $top = &$element['details']['top'];
    $top['actions']['#weight'] = 10;
    $top['#attributes']['class'] = array_diff($top['#attributes']['class'], ['clearfix']);
  }
}

/**
 * Implements hook_preprocess_HOOK() for views_exposed_form.
 */
function claro_preprocess_views_exposed_form(&$variables) {
  $form = &$variables['form'];

  // Add BEM classes for items in the form.
  // Sorted keys.
  $child_keys = Element::children($form, TRUE);
  $last_key = NULL;
  $child_before_actions_key = NULL;

  foreach ($child_keys as $child_key) {
    if (!empty($form[$child_key]['#type'])) {
      if ($form[$child_key]['#type'] === 'actions') {
        // We need the key of the element that precedes the actions element.
        $child_before_actions_key = $last_key;
        $form[$child_key]['#attributes']['class'][] = 'views-exposed-form__item';
        $form[$child_key]['#attributes']['class'][] = 'views-exposed-form__item--actions';
      }

      if (!in_array($form[$child_key]['#type'], ['hidden', 'actions'])) {
        $form[$child_key]['#wrapper_attributes']['class'][] = 'views-exposed-form__item';
        $last_key = $child_key;
      }
    }
  }

  if ($child_before_actions_key) {
    // Add a modifier class to the item that precedes the form actions.
    $form[$child_before_actions_key]['#wrapper_attributes']['class'][] = 'views-exposed-form__item--preceding-actions';
  }
}

/**
 * Implements hook_form_FORM_ID_alter() for views_exposed_form.
 */
function claro_form_views_exposed_form_alter(&$form, FormStateInterface $form_state) {
  $view = $form_state->getStorage()['view'];
  $view_title = $view->getTitle();

  // Add a label so screenreaders can identify the purpose of the exposed form
  // without having to scan content that appears further down the page.
  $form['#attributes']['aria-label'] = t('Filter the contents of the %view_title view', ['%view_title' => $view_title]);
}

/**
 * Implements hook_form_FORM_ID_alter() for the system_modules form.
 */
function claro_form_system_modules_alter(&$form, FormStateInterface $form_state) {
  if (isset($form['filters'])) {
    $form['filters']['#attributes']['class'][] = 'modules-table-filter';
    if (isset($form['filters']['text'])) {
      unset($form['filters']['text']['#title_display']);
      $form['filters']['text']['#title'] = t('Filter');
    }
  }

  // Convert module links to action links.
  foreach (Element::children($form['modules']) as $key) {
    $link_key_to_action_link_type = [
      'help' => 'questionmark',
      'permissions' => 'key',
      'configure' => 'cog',
    ];
    if (isset($form['modules'][$key]['#type']) && $form['modules'][$key]['#type'] === 'details') {
      $form['modules'][$key]['#module_package_listing'] = TRUE;
      foreach (Element::children($form['modules'][$key]) as $module_key) {
        if (isset($form['modules'][$key][$module_key]['links'])) {
          foreach ($form['modules'][$key][$module_key]['links'] as $link_key => &$link) {
            if (array_key_exists($link_key, $link_key_to_action_link_type)) {
              $action_link_type = $link_key_to_action_link_type[$link_key];
              $link['#options']['attributes']['class'][] = 'action-link';
              $link['#options']['attributes']['class'][] = 'action-link--small';
              $link['#options']['attributes']['class'][] = "action-link--icon-$action_link_type";
            }
          }
        }
      }
    }
  }
}

/**
 * Implements hook_preprocess_form_element().
 */
function claro_preprocess_form_element(&$variables) {
  if (!empty($variables['element']['#errors'])) {
    $variables['label']['#attributes']['class'][] = 'has-error';
  }

  if ($variables['disabled']) {
    $variables['label']['#attributes']['class'][] = 'is-disabled';

    if (!empty($variables['description']['attributes'])) {
      $variables['description']['attributes']->addClass('is-disabled');
    }
  }
}

/**
 * Implements template_preprocess_HOOK() for input.
 */
function claro_preprocess_input(&$variables) {
  if (
    !empty($variables['element']['#title_display']) &&
    $variables['element']['#title_display'] === 'attribute' &&
    !empty((string) $variables['element']['#title'])
  ) {
    $variables['attributes']['title'] = (string) $variables['element']['#title'];
  }

  $type_api = $variables['element']['#type'];
  $type_html = $variables['attributes']['type'];
  $text_types_html = [
    'text',
    'email',
    'tel',
    'number',
    'search',
    'password',
    'date',
    'time',
    'file',
    'color',
    'datetime-local',
    'url',
    'month',
    'week',
  ];

  if (in_array($type_html, $text_types_html)) {
    $variables['attributes']['class'][] = 'form-element';
    $variables['attributes']['class'][] = Html::getClass('form-element--type-' . $type_html);
    $variables['attributes']['class'][] = Html::getClass('form-element--api-' . $type_api);

    if (!empty($variables['element']['#autocomplete_route_name'])) {
      $variables['autocomplete_message'] = t('Loading…');
    }
  }

  if (in_array($type_html, ['checkbox', 'radio'])) {
    $variables['attributes']['class'][] = 'form-boolean';
    $variables['attributes']['class'][] = Html::getClass('form-boolean--type-' . $type_html);
  }
}

/**
 * Implements template_preprocess_HOOK() for select.
 */
function claro_preprocess_select(&$variables) {
  if (!empty($variables['element']['#title_display']) && $variables['element']['#title_display'] === 'attribute' && !empty((string) $variables['element']['#title'])) {
    $variables['attributes']['title'] = (string) $variables['element']['#title'];
  }

  $variables['attributes']['class'][] = 'form-element';
  $variables['attributes']['class'][] = $variables['element']['#multiple'] ?
    'form-element--type-select-multiple' :
    'form-element--type-select';

  if (in_array('block-region-select', $variables['attributes']['class'])) {
    $variables['attributes']['class'][] = 'form-element--extrasmall';
  }
}

/**
 * Implements template_preprocess_HOOK() for datetime_wrapper.
 */
function claro_preprocess_datetime_wrapper(&$variables) {
  if (!empty($variables['element']['#errors'])) {
    $variables['title_attributes']['class'][] = 'has-error';
  }

  if (!empty($variables['element']['#disabled'])) {
    $variables['title_attributes']['class'][] = 'is-disabled';

    if (!empty($variables['description_attributes'])) {
      $variables['description_attributes']->addClass('is-disabled');
    }
  }
}

/**
 * Implements template_preprocess_HOOK() for fieldset.
 */
function claro_preprocess_fieldset(&$variables) {
  $element = $variables['element'];
  $composite_types = ['checkboxes', 'radios'];

  if (!empty($element['#type']) && in_array($element['#type'], $composite_types) && !empty($variables['element']['#children_errors'])) {
    $variables['legend_span']['attributes']->addClass('has-error');
  }

  if (!empty($element['#disabled'])) {
    $variables['legend_span']['attributes']->addClass('is-disabled');

    if (!empty($variables['description']) && !empty($variables['description']['attributes'])) {
      $variables['description']['attributes']->addClass('is-disabled');
    }
  }

  // Remove 'container-inline' class from the main attributes and add a flag
  // instead.
  // @todo remove this after https://www.drupal.org/node/3059593 has been
  //   resolved.
  if (!empty($variables['attributes']['class'])) {
    $container_inline_key = array_search('container-inline', $variables['attributes']['class']);

    if ($container_inline_key !== FALSE) {
      unset($variables['attributes']['class'][$container_inline_key]);
      $variables['inline_items'] = TRUE;
    }
  }
}

/**
 * Implements hook_preprocess_HOOK() for field_multiple_value_form.
 */
function claro_preprocess_field_multiple_value_form(&$variables) {
  // Make disabled available for the template.
  $variables['disabled'] = !empty($variables['element']['#disabled']);

  if ($variables['multiple']) {
    // Add an additional CSS class for the field label table cell.
    // This repeats the logic of template_preprocess_field_multiple_value_form()
    // without using '#prefix' and '#suffix' for the wrapper element.
    //
    // If the field is multiple, we don't have to check the existence of the
    // table header cell.
    //
    // @see template_preprocess_field_multiple_value_form().
    $header_attributes = ['class' => ['form-item__label', 'form-item__label--multiple-value-form']];
    if (!empty($variables['element']['#required'])) {
      $header_attributes['class'][] = 'js-form-required';
      $header_attributes['class'][] = 'form-required';
    }
    // Using array_key_first() for addressing the first header cell would be
    // more elegant here, but we can rely on the related theme.inc preprocess.
    $variables['table']['#header'][0]['data'] = [
      '#type' => 'html_tag',
      '#tag' => 'h4',
      '#value' => $variables['element']['#title'],
      '#attributes' => $header_attributes,
    ];

    if ($variables['disabled']) {
      $variables['table']['#attributes']['class'][] = 'tabledrag-disabled';
      $variables['table']['#attributes']['class'][] = 'js-tabledrag-disabled';

      // We will add the 'is-disabled' CSS class to the disabled table header
      // cells.
      $header_attributes['class'][] = 'is-disabled';
      foreach ($variables['table']['#header'] as &$cell) {
        if (is_array($cell) && isset($cell['data'])) {
          $cell = $cell + ['class' => []];
          $cell['class'][] = 'is-disabled';
        }
        else {
          // We have to modify the structure of this header cell.
          $cell = [
            'data' => $cell,
            'class' => ['is-disabled'],
          ];
        }
      }
    }

    // Make add-more button smaller.
    if (!empty($variables['button'])) {
      $variables['button']['#attributes']['class'][] = 'button--small';
    }
  }
}

/**
 * Implements hook_preprocess_HOOK() for form_element__password_confirm.
 */
function claro_preprocess_form_element__password_confirm(&$variables) {
  // Add CSS classes needed for theming the password confirm widget.
  $variables['attributes']['class'][] = 'password-confirm';
  $variables['attributes']['class'][] = 'is-initial';
  $variables['attributes']['class'][] = 'is-password-empty';
  $variables['attributes']['class'][] = 'is-confirm-empty';
}

/**
 * Implements hook_preprocess_HOOK() for form_element__password.
 */
function claro_preprocess_form_element__password(&$variables) {
  if (!empty($variables['element']['#array_parents']) && in_array('pass1', $variables['element']['#array_parents'], TRUE)) {
    // This is the main password form element.
    $variables['attributes']['class'][] = 'password-confirm__password';
  }

  if (!empty($variables['element']['#array_parents']) && in_array('pass2', $variables['element']['#array_parents'], TRUE)) {
    // This is the password confirm form element.
    $variables['attributes']['class'][] = 'password-confirm__confirm';
  }
}

/**
 * Implements template_preprocess_HOOK() for filter_tips.
 */
function claro_preprocess_filter_tips(&$variables) {
  $variables['#attached']['library'][] = 'filter/drupal.filter';
}

/**
 * Implements template_preprocess_HOOK() for table.
 */
function claro_preprocess_table(&$variables) {
  // Adding table sort indicator CSS class for inactive sort link.
  // @todo Revisit after https://www.drupal.org/node/3025726 or
  // https://www.drupal.org/node/1973418 is in.
  if (!empty($variables['header'])) {
    foreach ($variables['header'] as &$header_cell) {
      if ($header_cell['content'] instanceof Link) {
        $query = $header_cell['content']->getUrl()->getOption('query') ?: [];

        if (isset($query['order']) && isset($query['sort'])) {
          $header_cell['attributes']->addClass('sortable-heading');
        }
      }
    }
  }

  // Mark the whole table and the first cells if rows are draggable.
  if (!empty($variables['rows'])) {
    $draggable_row_found = FALSE;
    foreach ($variables['rows'] as &$row) {
      /** @var \Drupal\Core\Template\Attribute $row['attributes'] */
      if (!empty($row['attributes']) && $row['attributes']->hasClass('draggable')) {
        if (!$draggable_row_found) {
          $variables['attributes']['class'][] = 'draggable-table';
          $draggable_row_found = TRUE;
        }

        reset($row['cells']);
        $first_cell_key = key($row['cells']);
        // The 'attributes' key is always here and it is an
        // \Drupal\Core\Template\Attribute.
        // @see template_preprocess_table();
        $row['cells'][$first_cell_key]['attributes']->addClass('tabledrag-cell');

        // Check that the first cell is empty or not.
        if (empty($row['cells'][$first_cell_key]) || empty($row['cells'][$first_cell_key]['content'])) {
          $row['cells'][$first_cell_key]['attributes']->addClass('tabledrag-cell--only-drag');
        }
      }
    }
  }
}

/**
 * Implements template_preprocess_HOOK() for field_ui_table.
 */
function claro_preprocess_field_ui_table(&$variables) {
  claro_preprocess_table($variables);
}

/**
 * Implements template_preprocess_HOOK() for views_view_table.
 *
 * @todo Revisit after https://www.drupal.org/node/3025726 or
 * https://www.drupal.org/node/1973418 is in.
 */
function claro_preprocess_views_view_table(&$variables) {
  if (!empty($variables['header'])) {
    foreach ($variables['header'] as &$header_cell) {
      if (!empty($header_cell['url'])) {
        $parsed_url = UrlHelper::parse($header_cell['url']);
        $query = !empty($parsed_url['query']) ? $parsed_url['query'] : [];

        if (isset($query['order']) && isset($query['sort'])) {
          $header_cell['attributes']->addClass('sortable-heading');
        }
      }
    }
  }
}

/**
 * Implements hook_preprocess_HOOK() for links__dropbutton.
 */
function claro_preprocess_links__dropbutton(&$variables) {
  // Add the right CSS class for the dropbutton list that helps reducing FOUC.
  if (!empty($variables['links'])) {
    $variables['attributes']['class'][] = count($variables['links']) > 1
      ? 'dropbutton--multiple'
      : 'dropbutton--single';
  }

  foreach ($variables['links'] as &$link_data) {
    $link_data['attributes']->addClass('dropbutton__item');
  }
}

/**
 * Implements hook_preprocess_HOOK() for views_ui_display_tab_bucket.
 */
function claro_preprocess_views_ui_display_tab_bucket(&$variables) {
  // Instead of re-styling Views UI dropbuttons with module-specific CSS styles,
  // change dropbutton variants to the extra small version.
  // @todo Revisit after https://www.drupal.org/node/3057581 is added.
  if (!empty($variables['actions']) && $variables['actions']['#type'] === 'dropbutton') {
    $variables['actions']['#dropbutton_type'] = 'extrasmall';
  }
}

/**
 * Implements hook_preprocess_HOOK() for status_messages.
 */
function claro_preprocess_status_messages(&$variables) {
  $variables['title_ids'] = [];
  foreach ($variables['message_list'] as $message_type => $messages) {
    $variables['title_ids'][$message_type] = Html::getUniqueId("message-$message_type-title");
  }
}

/**
 * Implements hook_preprocess_HOOK() for system_themes_page.
 */
function claro_preprocess_system_themes_page(&$variables) {
  if (!empty($variables['theme_groups'])) {
    foreach ($variables['theme_groups'] as &$theme_group) {
      if (!empty($theme_group['themes'])) {
        foreach ($theme_group['themes'] as &$theme_card) {
          /**
           * @todo Remove dependency on attributes after
           *   https://www.drupal.org/project/drupal/issues/2511548 has been
           *   resolved.
           */
          if (isset($theme_card['screenshot']['#attributes']) && $theme_card['screenshot']['#attributes'] instanceof Attribute && $theme_card['screenshot']['#attributes']->hasClass('no-screenshot')) {
            unset($theme_card['screenshot']);
          }

          $theme_card['title_id'] = Html::getUniqueId($theme_card['name'] . '-label');
          $description_is_empty = empty((string) $theme_card['description']);

          // Set description_id only if the description is not empty.
          if (!$description_is_empty) {
            $theme_card['description_id'] = Html::getUniqueId($theme_card['name'] . '-description');
          }

          if (!empty($theme_card['operations']) && !empty($theme_card['operations']['#theme']) && $theme_card['operations']['#theme'] === 'links') {
            $theme_card['operations']['#theme'] = 'links__action_links';
          }
        }
      }
    }
  }
}

/**
 * Implements hook_preprocess_HOOK() for links__action_links.
 */
function claro_preprocess_links__action_links(&$variables) {
  $variables['attributes']['class'][] = 'action-links';
  foreach ($variables['links'] as $delta => $link_item) {
    $variables['links'][$delta]['attributes']->addClass('action-links__item');
  }
}

/**
 * Implements hook_preprocess_HOOK() for file_managed_file.
 */
function claro_preprocess_file_managed_file(&$variables) {
  // Produce the same renderable element structure as image widget has.
  $child_keys = Element::children($variables['element']);
  foreach ($child_keys as $child_key) {
    $variables['data'][$child_key] = $variables['element'][$child_key];
  }

  _claro_preprocess_file_and_image_widget($variables);
}

/**
 * Implements hook_preprocess_HOOK() for file_widget_multiple.
 */
function claro_preprocess_file_widget_multiple(&$variables) {
  $has_upload = FALSE;

  if (isset($variables['table']['#type']) && $variables['table']['#type'] === 'table') {
    // Add a variant class for the table.
    $variables['table']['#attributes']['class'][] = 'table-file-multiple-widget';

    // Mark table disabled if the field widget is disabled.
    if (isset($variables['element']['#disabled']) && $variables['element']['#disabled']) {
      $variables['table']['#attributes']['class'][] = 'tabledrag-disabled';
      $variables['table']['#attributes']['class'][] = 'js-tabledrag-disabled';

      // We will add the 'is-disabled' CSS class to the disabled table header
      // cells.
      foreach ($variables['table']['#header'] as &$cell) {
        if (is_array($cell) && isset($cell['data'])) {
          $cell = $cell + ['class' => []];
          $cell['class'][] = 'is-disabled';
        }
        else {
          // We have to modify the structure of this header cell.
          $cell = [
            'data' => $cell,
            'class' => ['is-disabled'],
          ];
        }
      }
    }

    // Mark operations column cells with a CSS class.
    if (isset($variables['table']['#rows']) && is_array($variables['table']['#rows'])) {
      foreach ($variables['table']['#rows'] as $row_key => $row) {
        if (isset($row['data']) && is_array($row['data'])) {
          $last_cell = end($row['data']);
          $last_cell_key = key($row['data']);

          if (is_array($last_cell['data'])) {
            foreach ($last_cell['data'] as $last_cell_item) {
              if (isset($last_cell_item['#attributes']['class']) && is_array($last_cell_item['#attributes']['class']) && in_array('remove-button', $last_cell_item['#attributes']['class'])) {
                $variables['table']['#rows'][$row_key]['data'][$last_cell_key] += ['class' => []];
                $variables['table']['#rows'][$row_key]['data'][$last_cell_key]['class'][] = 'file-operations-cell';
                break 1;
              }
            }
          }
        }
      }
    }

    // Add a CSS class to the table if an upload widget is present.
    // This is required for removing the border of the last table row.
    if (!empty($variables['element'])) {
      $element_keys = Element::children($variables['element']);

      foreach ($element_keys as $delta) {
        if (!isset($variables['element'][$delta]['upload']['#access']) || $variables['element'][$delta]['upload']['#access'] !== FALSE) {
          $has_upload = TRUE;
          break 1;
        }
      }
    }
    $variables['table']['#attributes']['class'][] = $has_upload ? 'table-file-multiple-widget--has-upload' : 'table-file-multiple-widget--no-upload';
  }

  $table_is_not_empty = isset($variables['table']['#rows']) && !empty($variables['table']['#rows']);
  $table_is_accessible = !isset($variables['table']['#access']) || (isset($variables['table']['#access']) && $variables['table']['#access'] !== FALSE);
  $variables['has_table'] = $table_is_not_empty && $table_is_accessible;
}

/**
 * Implements hook_preprocess_HOOK() for image_widget.
 */
function claro_preprocess_image_widget(&$variables) {
  // This prevents image widget templates from rendering preview container HTML
  // to users that do not have permission to access these previews.
  // @todo revisit in https://drupal.org/node/953034
  // @todo revisit in https://drupal.org/node/3114318
  if (isset($variables['data']['preview']['#access']) && $variables['data']['preview']['#access'] === FALSE) {
    unset($variables['data']['preview']);
  }

  _claro_preprocess_file_and_image_widget($variables);
}

/**
 * Helper pre-process callback for file_managed_file and image_widget.
 *
 * @param array $variables
 *   The renderable array of image and file widgets, with 'element' and 'data'
 *   keys.
 */
function _claro_preprocess_file_and_image_widget(array &$variables) {
  $element = $variables['element'];
  $main_item_keys = [
    'upload',
    'upload_button',
    'remove_button',
  ];

  // Calculate helper values for the template.
  $upload_is_accessible = !isset($element['upload']['#access']) || $element['upload']['#access'] !== FALSE;
  $is_multiple = !empty($element['#cardinality']) && $element['#cardinality'] !== 1;
  $has_value = isset($element['#value']['fids']) && !empty($element['#value']['fids']);

  // File widget properties.
  $display_can_be_displayed = !empty($element['#display_field']);
  // Display is rendered in a separate table cell for multiple value widgets.
  $display_is_visible = $display_can_be_displayed && !$is_multiple && isset($element['display']['#type']) && $element['display']['#type'] !== 'hidden';
  $description_can_be_displayed = !empty($element['#description_field']);
  $description_is_visible = $description_can_be_displayed && isset($element['description']);

  // Image widget properties.
  $alt_can_be_displayed = !empty($element['#alt_field']);
  $alt_is_visible = $alt_can_be_displayed && (!isset($element['alt']['#access']) || $element['alt']['#access'] !== FALSE);
  $title_can_be_displayed = !empty($element['#title_field']);
  $title_is_visible = $title_can_be_displayed && (!isset($element['title']['#access']) || $element['title']['#access'] !== FALSE);

  $variables['multiple'] = $is_multiple;
  $variables['upload'] = $upload_is_accessible;
  $variables['has_value'] = $has_value;
  $variables['has_meta'] = $alt_is_visible || $title_is_visible || $display_is_visible || $description_is_visible;
  $variables['display'] = $display_is_visible;

  // Render file upload input and upload button (or file name and remove button,
  // if the field is not empty) in an emphasized div.
  foreach ($variables['data'] as $key => $item) {
    $item_is_filename = isset($item['filename']['#file']) && $item['filename']['#file'] instanceof FileInterface;

    // Move filename to main items.
    if ($item_is_filename) {
      $variables['main_items']['filename'] = $item;
      unset($variables['data'][$key]);
      continue;
    }

    // Move buttons, upload input and hidden items to main items.
    if (in_array($key, $main_item_keys)) {
      $variables['main_items'][$key] = $item;
      unset($variables['data'][$key]);
    }
  }
}

/**
 * Implements hook_preprocess_views_view_fields().
 *
 * This targets each rendered media item in the grid display of the media
 * library's modal dialog.
 */
function claro_preprocess_views_view_fields__media_library(array &$variables) {
  // Add classes to media rendered entity field so it can be targeted for
  // styling. Adding this class in a template is very difficult to do.
  if (isset($variables['fields']['rendered_entity']->wrapper_attributes)) {
    $variables['fields']['rendered_entity']->wrapper_attributes->addClass('media-library-item__click-to-select-trigger');
  }
}

/**
 * Implements hook_form_BASE_FORM_ID_alter().
 */
function claro_form_media_library_add_form_alter(array &$form, FormStateInterface $form_state) {
  $form['#attributes']['class'][] = 'media-library-add-form';
  $form['#attached']['library'][] = 'claro/media_library.theme';

  // If there are unsaved media items, apply styling classes to various parts
  // of the form.
  if (isset($form['media'])) {
    $form['#attributes']['class'][] = 'media-library-add-form--with-input';

    // Put a wrapper around the informational message above the unsaved media
    // items.
    $form['description']['#template'] = '<p class="media-library-add-form__description">{{ text }}</p>';
  }
  else {
    $form['#attributes']['class'][] = 'media-library-add-form--without-input';
  }
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function claro_form_media_library_add_form_upload_alter(array &$form, FormStateInterface $form_state) {
  $form['#attributes']['class'][] = 'media-library-add-form--upload';
  if (isset($form['container']['upload'])) {
    // Set this flag so we can prevent the details element from being added
    // in \Drupal\claro\ClaroPreRender::managedFile.
    $form['container']['upload']['#do_not_wrap_in_details'] = TRUE;
  }
  if (isset($form['container'])) {
    $form['container']['#attributes']['class'][] = 'media-library-add-form__input-wrapper';
  }
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function claro_form_media_library_add_form_oembed_alter(array &$form, FormStateInterface $form_state) {
  $form['#attributes']['class'][] = 'media-library-add-form--oembed';

  // If no media items have been added yet, add a couple of styling classes
  // to the initial URL form.
  if (isset($form['container'])) {
    $form['container']['#attributes']['class'][] = 'media-library-add-form__input-wrapper';
    $form['container']['url']['#attributes']['class'][] = 'media-library-add-form-oembed-url';
    $form['container']['submit']['#attributes']['class'][] = 'media-library-add-form-oembed-submit';
  }
}

/**
 * Implements hook_preprocess_item_list__media_library_add_form_media_list().
 *
 * This targets each new, unsaved media item added to the media library, before
 * they are saved.
 */
function claro_preprocess_item_list__media_library_add_form_media_list(array &$variables) {
  foreach ($variables['items'] as &$item) {
    $item['value']['preview']['#attributes']['class'][] = 'media-library-add-form__preview';
    $item['value']['fields']['#attributes']['class'][] = 'media-library-add-form__fields';
    $item['value']['remove_button']['#attributes']['class'][] = 'media-library-add-form__remove-button';

    $item['value']['remove_button']['#attributes']['class'][] = 'button--extrasmall';
    // #source_field_name is set by AddFormBase::buildEntityFormElement()
    // to help themes and form_alter hooks identify the source field.
    $fields = &$item['value']['fields'];
    $source_field_name = $fields['#source_field_name'];

    // Set this flag so we can remove the details element.
    $fields[$source_field_name]['widget'][0]['#do_not_wrap_in_details'] = TRUE;

    if (isset($fields[$source_field_name])) {
      $fields[$source_field_name]['#attributes']['class'][] = 'media-library-add-form__source-field';
    }
  }
}

/**
 * Implements hook_preprocess_media_library_item__widget().
 *
 * This targets each media item selected in an entity reference field.
 */
function claro_preprocess_media_library_item__widget(array &$variables) {
  $variables['content']['remove_button']['#attributes']['class'][] = 'media-library-item__remove';
  $variables['content']['remove_button']['#attributes']['class'][] = 'icon-link';
}

/**
 * Implements hook_preprocess_media_library_item__small().
 *
 * This targets each pre-selected media item selected when adding new media in
 * the modal media library dialog.
 */
function claro_preprocess_media_library_item__small(array &$variables) {
  $variables['content']['select']['#attributes']['class'][] = 'media-library-item__click-to-select-checkbox';
}

/**
 * @todo Remove this when https://www.drupal.org/project/drupal/issues/2999549
 * lands.
 *
 * @see \Drupal\media_library\Plugin\Field\FieldWidget\MediaLibraryWidget::formElement()
 */
function claro_preprocess_fieldset__media_library_widget(array &$variables) {
  if (isset($variables['prefix']['weight_toggle'])) {
    $variables['prefix']['weight_toggle']['#attributes']['class'][] = 'action-link';
    $variables['prefix']['weight_toggle']['#attributes']['class'][] = 'action-link--extrasmall';
    $variables['prefix']['weight_toggle']['#attributes']['class'][] = 'action-link--icon-show';
    $variables['prefix']['weight_toggle']['#attributes']['class'][] = 'media-library-widget__toggle-weight';
  }
  if (isset($variables['suffix']['open_button'])) {
    $variables['suffix']['open_button']['#attributes']['class'][] = 'media-library-open-button';
  }
}

/**
 * Implements hook_views_pre_render().
 */
function claro_views_pre_render(ViewExecutable $view) {
  $add_classes = function (&$option, array $classes_to_add) {
    $classes = preg_split('/\s+/', $option);
    $classes = array_filter($classes);
    $classes = array_merge($classes, $classes_to_add);
    $option = implode(' ', array_unique($classes));
  };

  if ($view->id() === 'media_library') {
    if ($view->display_handler->options['defaults']['css_class']) {
      $add_classes($view->displayHandlers->get('default')->options['css_class'], ['media-library-view']);
    }
    else {
      $add_classes($view->display_handler->options['css_class'], ['media-library-view']);
    }

    if ($view->current_display === 'page') {
      if (array_key_exists('media_bulk_form', $view->field)) {
        $add_classes($view->field['media_bulk_form']->options['element_class'], ['media-library-item__click-to-select-checkbox']);
      }
      if (array_key_exists('rendered_entity', $view->field)) {
        $add_classes($view->field['rendered_entity']->options['element_class'], ['media-library-item__content']);
      }
      if (array_key_exists('edit_media', $view->field)) {
        $add_classes($view->field['edit_media']->options['alter']['link_class'], ['media-library-item__edit']);
        $add_classes($view->field['edit_media']->options['alter']['link_class'], ['icon-link']);
      }
      if (array_key_exists('delete_media', $view->field)) {
        $add_classes($view->field['delete_media']->options['alter']['link_class'], ['media-library-item__remove']);
        $add_classes($view->field['delete_media']->options['alter']['link_class'], ['icon-link']);
      }
    }
    elseif (strpos($view->current_display, 'widget') === 0) {
      if (array_key_exists('rendered_entity', $view->field)) {
        $add_classes($view->field['rendered_entity']->options['element_class'], ['media-library-item__content']);
      }
      if (array_key_exists('media_library_select_form', $view->field)) {
        $add_classes($view->field['media_library_select_form']->options['element_wrapper_class'], ['media-library-item__click-to-select-checkbox']);
      }

      if ($view->display_handler->options['defaults']['css_class']) {
        $add_classes($view->displayHandlers->get('default')->options['css_class'], ['media-library-view--widget']);
      }
      else {
        $add_classes($view->display_handler->options['css_class'], ['media-library-view--widget']);
      }
    }
  }
}

/**
 * Implements hook_preprocess_links__media_library_menu().
 *
 * This targets the menu of available media types in the media library's modal
 * dialog.
 *
 * @todo Do this in the relevant template once
 *   https://www.drupal.org/project/drupal/issues/3088856 is resolved.
 */
function claro_preprocess_links__media_library_menu(array &$variables) {
  foreach ($variables['links'] as &$link) {
    // Add a class to the Media Library menu items.
    $link['attributes']->addClass('media-library-menu__item');
    $link['link']['#options']['attributes']['class'][] = 'media-library-menu__link';
  }
}

/**
 * Implements hook_form_FORM_ID_alter() for the Views UI rearrange filter form.
 */
function claro_preprocess_views_ui_rearrange_filter_form(array &$variables) {
  foreach ($variables['table']['#rows'] as &$row) {
    // Remove the container-inline class from the operator table cell.
    if (isset($row['data'][0]['class'])) {
      $row['data'][0]['class'] = array_diff($row['data'][0]['class'], ['container-inline']);
    }
  }
}

/**
 * Implements hook_form_FORM_ID_alter() for the Views UI config form.
 */
function claro_form_views_ui_config_item_form_alter(array &$form, FormStateInterface $form_state) {
  $type = $form_state->get('type');

  if ($type === 'filter') {
    // Remove clearfix classes from several elements. They add unwanted
    // whitespace and are no longer needed because uses of `float:` in this form
    // have been removed.
    // @todo Many of the changes to classes within this conditional may not be
    // needed or require refactoring in https://drupal.org/node/3164890
    unset($form['options']['clear_markup_start']);
    unset($form['options']['clear_markup_end']);
    $form['options']['expose_button']['#prefix'] = str_replace('clearfix', '', $form['options']['expose_button']['#prefix']);
    if (isset($form['options']['group_button']['#prefix'])) {
      $form['options']['group_button']['#prefix'] = str_replace('clearfix', '', $form['options']['group_button']['#prefix']);
    }

    // Remove `views-(direction)-(amount)` classes, replace with
    // `views-group-box--operator`, and add a `views-config-group-region`
    // wrapper.
    if (isset($form['options']['operator']['#prefix'])) {
      foreach (['views-left-30', 'views-left-40'] as $left_class) {
        if (strpos($form['options']['operator']['#prefix'], $left_class) !== FALSE) {
          $form['options']['operator']['#prefix'] = '<div class="views-config-group-region">' . str_replace($left_class, 'views-group-box--operator', $form['options']['operator']['#prefix']);
          $form['options']['value']['#suffix'] = $form['options']['value']['#suffix'] . '</div>';
        }
      }
    }

    // Some instances of this form input have an added wrapper that needs to be
    // removed in order to style these forms consistently.
    // @see \Drupal\views\Plugin\views\filter\InOperator::valueForm
    $wrapper_div_to_remove = '<div id="edit-options-value-wrapper">';
    if (isset($form['options']['value']['#prefix']) && strpos($form['options']['value']['#prefix'], $wrapper_div_to_remove) !== FALSE) {
      $form['options']['value']['#prefix'] = str_replace($wrapper_div_to_remove, '', $form['options']['value']['#prefix']);
      $form['options']['value']['#suffix'] = preg_replace('/<\/div>/', '', $form['options']['value']['#suffix'], 1);
    }

    if (isset($form['options']['value']['#prefix'])) {
      foreach (['views-right-70', 'views-right-60'] as $right_class) {
        if (strpos($form['options']['value']['#prefix'], $right_class) !== FALSE) {
          $form['options']['value']['#prefix'] = str_replace($right_class, 'views-group-box--value', $form['options']['value']['#prefix']);
        }
      }
    }

    // If the form includes a `value` field, the `.views-group-box--value` and
    // `.views-group-box` classes must be present in a wrapper div. Add them
    // here if it they are not yet present.
    if (!isset($form['options']['value']['#prefix']) || strpos($form['options']['value']['#prefix'], 'views-group-box--value') === FALSE) {
      $prefix = $form['options']['value']['#prefix'] ?? '';
      $suffix = $form['options']['value']['#suffix'] ?? '';
      $form['options']['value']['#prefix'] = '<div class="views-group-box views-group-box--value">' . $prefix;
      $form['options']['value']['#suffix'] = $suffix . '</div>';
    }

    // If operator or value have no children, remove them from the render array
    // so their prefixes and suffixes aren't added without any content.
    foreach (['operator', 'value'] as $form_item) {
      if (isset($form['options'][$form_item]) && count($form['options'][$form_item]) === 2 && isset($form['options'][$form_item]['#prefix']) && $form['options'][$form_item]['#suffix']) {
        unset($form['options'][$form_item]);
      }
    }
  }
}

/**
 * Implements hook_form_FORM_ID_alter() for Views UI add handler form.
 */
function claro_form_views_ui_add_handler_form_alter(array &$form, FormStateInterface $form_state) {
  // Remove container-inline class to allow more control over styling.
  if (isset($form['selected']['#attributes']['class'])) {
    $form['selected']['#attributes']['class'] = array_diff($form['selected']['#attributes']['class'], ['container-inline']);
  }
  // Move all form elements in controls to its parent, this places them all in
  // the same div, which makes it possible to position them with flex styling
  // instead of floats.
  if (isset($form['override']['controls'])) {
    foreach (Element::children($form['override']['controls']) as $key) {
      $form['override']["controls_$key"] = $form['override']['controls'][$key];

      // The wrapper array for controls is removed after this loop completes.
      // The wrapper ensured that its child elements were hidden in browsers
      // without JavaScript. To replicate this functionality, the `.js-show`
      // class is added to each item previously contained in the wrapper.
      if (isset($form['override']['controls']['#id']) && $form['override']['controls']['#id'] === 'views-filterable-options-controls') {
        $form['override']["controls_$key"]['#wrapper_attributes']['class'][] = 'js-show';
      }
    }

    unset($form['override']['controls']);
  }
}

/**
 * Implements hook_preprocess_toolbar().
 *
 * This is also called by system_preprocess_toolbar() in instances where Claro
 * is the admin theme but not the active theme.
 *
 * @see system_preprocess_toolbar()
 */
function claro_preprocess_toolbar(&$variables, $hook, $info) {
  $variables['attributes']['data-drupal-claro-processed-toolbar'] = TRUE;
}

/**
 * Called by system.module via its hook_library_info_alter().
 *
 * If the active theme is not Claro, but Claro is the admin theme, this alters
 * the toolbar library config so Claro's toolbar stylesheets are used.
 *
 * @see system_library_info_alter()
 */
function claro_system_module_invoked_library_info_alter(&$libraries, $extension) {
  if ($extension === 'toolbar') {
    $claro_info = \Drupal::service('theme_handler')->listInfo()['claro']->info;
    $path_prefix = '/core/themes/claro/';
    $claro_toolbar_overrides = $claro_info['libraries-override']['toolbar/toolbar'];
    foreach ($claro_toolbar_overrides['css'] as $concern => $overrides) {
      foreach ($claro_toolbar_overrides['css'][$concern] as $key => $value) {
        $config = $libraries['toolbar']['css'][$concern][$key];
        $libraries['toolbar']['css'][$concern][$path_prefix . $value] = $config;
        unset($libraries['toolbar']['css'][$concern][$key]);
      }
    }
    $claro_toolbar_menu_overrides = $claro_info['libraries-override']['toolbar/toolbar.menu'];
    foreach ($claro_toolbar_menu_overrides['css'] as $concern => $overrides) {
      foreach ($claro_toolbar_menu_overrides['css'][$concern] as $key => $value) {
        $config = $libraries['toolbar.menu']['css'][$concern][$key];
        $libraries['toolbar.menu']['css'][$concern][$path_prefix . $value] = $config;
        unset($libraries['toolbar.menu']['css'][$concern][$key]);
      }
    }
  }
}

/**
 * Called by system.module via its hook_theme_registry_alter().
 *
 * If the active theme is not Claro, but Claro is the admin theme, this alters
 * the registry so Claro's toolbar templates are used.
 *
 * @see system_theme_registry_alter()
 */
function claro_system_module_invoked_theme_registry_alter(array &$theme_registry) {
  foreach (['toolbar', 'menu__toolbar'] as $registry_item) {
    if (isset($theme_registry[$registry_item])) {
      $theme_registry[$registry_item]['path'] = 'core/themes/claro/templates/navigation';
    }
  }
}