eZ\Publish\Core\Helper\ContentPreviewHelper::isPreviewActive PHP Method

    public function isPreviewActive()
    {
        return $this->previewActive;
    }

 /**
  * Renders the legacy website toolbar template.
  *
  * If the logged in user doesn't have the required permission, an empty response is returned
  *
  * @param mixed $locationId
  * @param Request $request
  *
  * @return Response
  */
 public function websiteToolbarAction($locationId, Request $request)
 {
     $response = new Response();
     if (isset($this->csrfProvider)) {
         $parameters['form_token'] = $this->csrfProvider->generateCsrfToken('legacy');
     }
     if ($this->previewHelper->isPreviewActive()) {
         $template = 'design:parts/website_toolbar_versionview.tpl';
         $previewedContent = $authValueObject = $this->previewHelper->getPreviewedContent();
         $previewedVersionInfo = $previewedContent->versionInfo;
         $parameters = array('object' => $previewedContent, 'version' => $previewedVersionInfo, 'language' => $previewedVersionInfo->initialLanguageCode, 'is_creator' => $previewedVersionInfo->creatorId === $this->getRepository()->getCurrentUser()->id);
     } elseif ($locationId === null) {
         return $response;
     } else {
         $authValueObject = $this->loadContentByLocationId($locationId);
         $template = 'design:parts/website_toolbar.tpl';
         $parameters = array('current_node_id' => $locationId, 'redirect_uri' => $request->attributes->get('semanticPathinfo'));
     }
     $authorizationAttribute = new AuthorizationAttribute('websitetoolbar', 'use', array('valueObject' => $authValueObject));
     if (!$this->authChecker->isGranted($authorizationAttribute)) {
         return $response;
     }
     $response->setContent($this->legacyTemplateEngine->render($template, $parameters));
     return $response;
 }