Pager.php

<?php

namespace Drupal\views_slideshow\Plugin\ViewsSlideshowWidgetType;

use Drupal\Core\Form\FormStateInterface;
use Drupal\views_slideshow\ViewsSlideshowWidgetTypeBase;

/**
 * Provides a pager widget type.
 *
 * @ViewsSlideshowWidgetType(
 *   id = "views_slideshow_pager",
 *   label = @Translation("Pager"),
 *   accepts = {
 *     "transitionBegin" = {"required" = TRUE},
 *     "goToSlide",
 *     "previousSlide",
 *     "nextSlide"
 *   },
 *   calls = {"goToSlide", "pause", "play"}
 * )
 */
class Pager extends ViewsSlideshowWidgetTypeBase {
    
    /**
     * {@inheritdoc}
     */
    public function defaultConfiguration() {
        $options = parent::defaultConfiguration() + [
            'type' => [
                'default' => 0,
            ],
            'views_slideshow_pager_numbered_hover' => [
                'default' => 0,
            ],
            'views_slideshow_pager_numbered_click_to_page' => [
                'default' => 0,
            ],
            'views_slideshow_pager_thumbnails_hover' => [
                'default' => 0,
            ],
            'views_slideshow_pager_thumbnails_click_to_page' => [
                'default' => 0,
            ],
        ];
        
        /**
         * @var \Drupal\Component\Plugin\PluginManagerInterface
         */
        $widgetManager = \Drupal::service('plugin.manager.views_slideshow.widget');
        // Get default configuration of all Pager plugins.
        foreach ($widgetManager->getDefinitions($this->getPluginId()) as $widget_id => $widget_info) {
            $options += $widgetManager->createInstance($widget_id, [])
                ->defaultConfiguration();
        }
        return $options;
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
        $form = parent::buildConfigurationForm($form, $form_state);
        $view = $form_state->get('view')
            ->get('executable');
        
        /**
         * @var \Drupal\Component\Plugin\PluginManagerInterface
         */
        $widgetManager = \Drupal::service('plugin.manager.views_slideshow.widget');
        // Determine if this widget type is compatible with any slideshow type.
        $widgets = [];
        foreach ($widgetManager->getDefinitions($this->getPluginId()) as $widget_id => $widget_info) {
            if ($widgetManager->createInstance($widget_id, [])
                ->checkCompatiblity($view)) {
                $widgets[$widget_id] = $widget_info['label'];
            }
        }
        if (!empty($widgets)) {
            // Need to wrap this so it indents correctly.
            $form['views_slideshow_pager_wrapper'] = [
                '#markup' => '<div class="vs-dependent">',
            ];
            // Create the widget type field.
            $form['type'] = [
                '#type' => 'select',
                '#title' => $this->t('Pager Type'),
                '#description' => $this->t('Style of the pager'),
                '#default_value' => $this->getConfiguration()['type'],
                '#options' => $widgets,
                '#states' => [
                    'visible' => [
                        ':input[name="' . $this->getConfiguration()['dependency'] . '[enable]"]' => [
                            'checked' => TRUE,
                        ],
                    ],
                ],
            ];
            foreach ($widgetManager->getDefinitions() as $widget_id => $widget_info) {
                // Get the current configuration of this widget.
                $configuration = [];
                if (!empty($this->getConfiguration()[$widget_id])) {
                    $configuration = $this->getConfiguration()[$widget_id];
                }
                $configuration['dependency'] = $this->getConfiguration()['dependency'];
                $configuration['view'] = $view;
                $instance = $widgetManager->createInstance($widget_id, $configuration);
                // Get the configuration form of this widget type.
                $form[$widget_id] = isset($form[$widget_id]) ? $form[$widget_id] : [];
                $form[$widget_id] = $instance->buildConfigurationForm($form[$widget_id], $form_state);
            }
            $form['views_slideshow_pager_wrapper_close'] = [
                '#markup' => '</div>',
            ];
        }
        else {
            $form['enable_pager'] = [
                '#markup' => 'There are no pagers available.',
            ];
        }
        return $form;
    }

}