class BlockDisplayVariant

abstract class BlockDisplayVariant extends VariantBase implements ContextAwareVariantInterface, ContainerFactoryPluginInterface, BlockVariantInterface {
    use AjaxFormTrait;
    use BlockVariantTrait;
    
    /**
     * The context handler.
     *
     * @var \Drupal\Core\Plugin\Context\ContextHandlerInterface
     */
    protected $contextHandler;
    
    /**
     * The UUID generator.
     *
     * @var \Drupal\Component\Uuid\UuidInterface
     */
    protected $uuidGenerator;
    
    /**
     * The current user.
     *
     * @var \Drupal\Core\Session\AccountInterface
     */
    protected $account;
    
    /**
     * The token service.
     *
     * @var \Drupal\Core\Utility\Token
     */
    protected $token;
    
    /**
     * An array of collected contexts.
     *
     * This is only used on runtime, and is not stored.
     *
     * @var \Drupal\Component\Plugin\Context\ContextInterface[]
     */
    protected $contexts = [];
    
    /**
     * Constructs a new BlockDisplayVariant.
     *
     * @param array $configuration
     *   A configuration array containing information about the plugin instance.
     * @param string $plugin_id
     *   The plugin ID for the plugin instance.
     * @param mixed $plugin_definition
     *   The plugin implementation definition.
     * @param \Drupal\Core\Plugin\Context\ContextHandlerInterface $context_handler
     *   The context handler.
     * @param \Drupal\Core\Session\AccountInterface $account
     *   The current user.
     * @param \Drupal\Component\Uuid\UuidInterface $uuid_generator
     *   The UUID generator.
     * @param \Drupal\Core\Utility\Token $token
     *   The token service.
     * @param \Drupal\Core\Block\BlockManagerInterface $block_manager
     *   The block manager.
     * @param \Drupal\Core\Condition\ConditionManager $condition_manager
     *   The condition manager.
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, ContextHandlerInterface $context_handler, AccountInterface $account, UuidInterface $uuid_generator, Token $token, BlockManagerInterface $block_manager, ConditionManager $condition_manager) {
        // Inject dependencies as early as possible, so they can be used in
        // configuration.
        $this->contextHandler = $context_handler;
        $this->account = $account;
        $this->uuidGenerator = $uuid_generator;
        $this->token = $token;
        $this->blockManager = $block_manager;
        $this->conditionManager = $condition_manager;
        parent::__construct($configuration, $plugin_id, $plugin_definition);
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
        return new static($configuration, $plugin_id, $plugin_definition, $container->get('context.handler'), $container->get('current_user'), $container->get('uuid'), $container->get('token'), $container->get('plugin.manager.block'), $container->get('plugin.manager.condition'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function defaultConfiguration() {
        return parent::defaultConfiguration() + [
            'blocks' => [],
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function calculateDependencies() {
        foreach ($this->getBlockCollection() as $instance) {
            $this->calculatePluginDependencies($instance);
        }
        return $this->dependencies;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getConfiguration() {
        return [
            'blocks' => $this->getBlockCollection()
                ->getConfiguration(),
        ] + parent::getConfiguration();
    }
    
    /**
     * {@inheritdoc}
     */
    public function setConfiguration(array $configuration) {
        // Preserve the uuid.
        if ($this->configuration && !empty($this->configuration['uuid'])) {
            $configuration['uuid'] = $this->configuration['uuid'];
        }
        parent::setConfiguration($configuration);
        $this->getBlockCollection()
            ->setConfiguration($this->configuration['blocks']);
        return $this;
    }
    
    /**
     * Gets the contexts.
     *
     * @return \Drupal\Component\Plugin\Context\ContextInterface[]
     *   An array of set contexts, keyed by context name.
     */
    public function getContexts() {
        return $this->contexts;
    }
    
    /**
     * Sets the contexts.
     *
     * @param \Drupal\Component\Plugin\Context\ContextInterface[] $contexts
     *   An array of contexts, keyed by context name.
     *
     * @return $this
     */
    public function setContexts(array $contexts) {
        $this->contexts = $contexts;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    protected function contextHandler() {
        return $this->contextHandler;
    }
    
    /**
     * {@inheritdoc}
     */
    protected function getBlockConfig() {
        return $this->configuration['blocks'];
    }
    
    /**
     * {@inheritdoc}
     */
    protected function uuidGenerator() {
        return $this->uuidGenerator;
    }
    
    /**
     * {@inheritdoc}
     */
    public function __sleep() {
        $vars = parent::__sleep();
        // Gathered contexts objects should not be serialized.
        if (($key = array_search('contexts', $vars)) !== FALSE) {
            unset($vars[$key]);
        }
        // The block plugin collection should also not be serialized, ensure that
        // configuration is synced back.
        if (($key = array_search('blockPluginCollection', $vars)) !== FALSE) {
            if ($this->blockPluginCollection) {
                $this->configuration['blocks'] = $this->blockPluginCollection
                    ->getConfiguration();
            }
            unset($vars[$key]);
        }
        return $vars;
    }

}