class Controls

class Controls extends ViewsSlideshowWidgetTypeBase {
    
    /**
     * {@inheritdoc}
     */
    public function defaultConfiguration() {
        return parent::defaultConfiguration() + [
            'type' => [
                'default' => 0,
            ],
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
        $form = parent::buildConfigurationForm($form, $form_state);
        
        /**
         * @var \Drupal\Component\Plugin\PluginManagerInterface
         */
        $widgetManager = \Drupal::service('plugin.manager.views_slideshow.widget');
        $widgets = $widgetManager->getDefinitions($this->getPluginId());
        if (!empty($widgets)) {
            $options = [];
            foreach ($widgets as $widgetId => $widgetInfo) {
                $options[$widgetId] = $widgetInfo['label'];
            }
            // Need to wrap this so it indents correctly.
            $form['views_slideshow_controls_wrapper'] = [
                '#markup' => '<div class="vs-dependent">',
            ];
            // Create the widget type field.
            $form['type'] = [
                '#type' => 'select',
                '#title' => $this->t('Controls Type'),
                '#description' => $this->t('Style of the controls'),
                '#default_value' => $this->getConfiguration()['type'],
                '#options' => $options,
                '#states' => [
                    'visible' => [
                        ':input[name="' . $this->getConfiguration()['dependency'] . '[enable]"]' => [
                            'checked' => TRUE,
                        ],
                    ],
                ],
            ];
            foreach ($widgets 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'];
                $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['controls_wrapper_close'] = [
                '#markup' => '</div>',
            ];
        }
        else {
            $form['enable_controls'] = [
                '#markup' => 'There are no controls available.',
            ];
        }
        return $form;
    }

}