Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\Theme;
Chris@0: 
Chris@0: use Drupal\Core\Access\AccessResult;
Chris@0: use Drupal\Core\Extension\ThemeHandlerInterface;
Chris@0: use Drupal\Core\Routing\Access\AccessInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * Provides access checking for themes for routing and theme negotiation.
Chris@0:  */
Chris@0: class ThemeAccessCheck implements AccessInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * The theme handler.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Extension\ThemeHandlerInterface
Chris@0:    */
Chris@0:   protected $themeHandler;
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a \Drupal\Core\Theme\Registry object.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Extension\ThemeHandlerInterface $theme_handler
Chris@0:    *   The theme handler.
Chris@0:    */
Chris@0:   public function __construct(ThemeHandlerInterface $theme_handler) {
Chris@0:     $this->themeHandler = $theme_handler;
Chris@0:   }
Chris@17: 
Chris@0:   /**
Chris@0:    * Checks access to the theme for routing.
Chris@0:    *
Chris@0:    * @param string $theme
Chris@0:    *   The name of a theme.
Chris@0:    *
Chris@0:    * @return \Drupal\Core\Access\AccessResultInterface
Chris@0:    *   The access result.
Chris@0:    */
Chris@0:   public function access($theme) {
Chris@0:     // Cacheable until the theme settings are modified.
Chris@0:     return AccessResult::allowedIf($this->checkAccess($theme))->addCacheTags(['config:' . $theme . '.settings']);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Indicates whether the theme is accessible based on whether it is installed.
Chris@0:    *
Chris@0:    * @param string $theme
Chris@0:    *   The name of a theme.
Chris@0:    *
Chris@0:    * @return bool
Chris@0:    *   TRUE if the theme is installed, FALSE otherwise.
Chris@0:    */
Chris@0:   public function checkAccess($theme) {
Chris@0:     $themes = $this->themeHandler->listInfo();
Chris@0:     return !empty($themes[$theme]->status);
Chris@0:   }
Chris@0: 
Chris@0: }