class MenuListBuilder

class MenuListBuilder extends ConfigEntityListBuilder {
    
    /**
     * {@inheritdoc}
     */
    protected function getEntityIds() {
        $query = $this->getStorage()
            ->getQuery()
            ->sort('label', 'ASC');
        // Only add the pager if a limit is specified.
        if ($this->limit) {
            $query->pager($this->limit);
        }
        return $query->execute();
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildHeader() {
        $header['title'] = t('Title');
        $header['description'] = [
            'data' => t('Description'),
            'class' => [
                RESPONSIVE_PRIORITY_MEDIUM,
            ],
        ];
        return $header + parent::buildHeader();
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildRow(EntityInterface $entity) {
        $row['title'] = [
            'data' => $entity->label(),
            'class' => [
                'menu-label',
            ],
        ];
        $row['description']['data'] = [
            '#markup' => $entity->getDescription(),
        ];
        return $row + parent::buildRow($entity);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDefaultOperations(EntityInterface $entity) {
        $operations = parent::getDefaultOperations($entity);
        if (isset($operations['edit'])) {
            $operations['edit']['title'] = t('Edit menu');
            $operations['add'] = [
                'title' => t('Add link'),
                'weight' => 20,
                'url' => $entity->toUrl('add-link-form'),
                'query' => [
                    'destination' => $entity->toUrl('edit-form')
                        ->toString(),
                ],
            ];
        }
        if (isset($operations['delete'])) {
            $operations['delete']['title'] = t('Delete menu');
        }
        return $operations;
    }
    
    /**
     * {@inheritdoc}
     */
    protected function ensureDestination(Url $url) {
        // We don't want to add the destination URL here, as it means we get
        // redirected back to the list-builder after adding/deleting menu links from
        // a menu.
        return $url;
    }
    
    /**
     * {@inheritdoc}
     */
    public function render() {
        $build = parent::render();
        $build['#attached']['library'][] = "menu_ui/drupal.menu_ui.adminforms";
        return $build;
    }

}