class Display

class Display extends ViewsFormBase {
    
    /**
     * Constructs a new Display object.
     */
    public function __construct($type = NULL) {
        $this->setType($type);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFormKey() {
        return 'display';
    }
    
    /**
     * {@inheritdoc}
     *
     * @todo Remove this and switch all usage of $form_state->get('section') to
     *   $form_state->get('type').
     */
    public function getFormState(ViewEntityInterface $view, $display_id, $js) {
        $form_state = parent::getFormState($view, $display_id, $js);
        $form_state->set('section', $this->type);
        return $form_state;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getForm(ViewEntityInterface $view, $display_id, $js, $type = NULL) {
        $this->setType($type);
        return parent::getForm($view, $display_id, $js);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'views_ui_edit_display_form';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        $view = $form_state->get('view');
        $display_id = $form_state->get('display_id');
        $executable = $view->getExecutable();
        if (!$executable->setDisplay($display_id)) {
            $form['markup'] = [
                '#markup' => $this->t('Invalid display id @display', [
                    '@display' => $display_id,
                ]),
            ];
            return $form;
        }
        // Get form from the handler.
        $form['options'] = [
            '#theme_wrappers' => [
                'container',
            ],
            '#attributes' => [
                'class' => [
                    'scroll',
                ],
                'data-drupal-views-scroll' => TRUE,
            ],
        ];
        $executable->display_handler
            ->buildOptionsForm($form['options'], $form_state);
        // The handler options form sets $form['#title'], which we need on the entire
        // $form instead of just the ['options'] section.
        $form['#title'] = $form['options']['#title'];
        unset($form['options']['#title']);
        // Move the override dropdown out of the scrollable section of the form.
        if (isset($form['options']['override'])) {
            $form['override'] = $form['options']['override'];
            unset($form['options']['override']);
        }
        $name = $form_state->get('update_name');
        $view->getStandardButtons($form, $form_state, 'views_ui_edit_display_form', $name);
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function validateForm(array &$form, FormStateInterface $form_state) {
        $view = $form_state->get('view');
        $display_id = $form_state->get('display_id');
        $view->getExecutable()->displayHandlers
            ->get($display_id)
            ->validateOptionsForm($form['options'], $form_state);
        if ($form_state->getErrors()) {
            $form_state->set('rerender', TRUE);
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
        $view = $form_state->get('view');
        $display_id = $form_state->get('display_id');
        $view->getExecutable()->displayHandlers
            ->get($display_id)
            ->submitOptionsForm($form['options'], $form_state);
        $view->cacheSet();
    }

}