class VariantBase

abstract class VariantBase extends PluginBase implements VariantInterface {
    use PluginDependencyTrait;
    use RefinableCacheableDependencyTrait;
    
    /**
     * {@inheritdoc}
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition) {
        parent::__construct($configuration, $plugin_id, $plugin_definition);
        $this->setConfiguration($configuration);
    }
    
    /**
     * {@inheritdoc}
     */
    public function label() {
        return $this->configuration['label'];
    }
    
    /**
     * {@inheritdoc}
     */
    public function adminLabel() {
        return $this->pluginDefinition['admin_label'];
    }
    
    /**
     * {@inheritdoc}
     */
    public function id() {
        return $this->configuration['uuid'];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getWeight() {
        return (int) $this->configuration['weight'];
    }
    
    /**
     * {@inheritdoc}
     */
    public function setWeight($weight) {
        $this->configuration['weight'] = (int) $weight;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getConfiguration() {
        return [
            'id' => $this->getPluginId(),
        ] + $this->configuration;
    }
    
    /**
     * {@inheritdoc}
     */
    public function setConfiguration(array $configuration) {
        $this->configuration = $configuration + $this->defaultConfiguration();
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function defaultConfiguration() {
        return [
            'label' => '',
            'uuid' => '',
            'weight' => 0,
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function calculateDependencies() {
        return $this->dependencies;
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
        $form['label'] = [
            '#type' => 'textfield',
            '#title' => $this->t('Label'),
            '#description' => $this->t('The label for this display variant.'),
            '#default_value' => $this->label(),
            '#maxlength' => '255',
        ];
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function validateConfigurationForm(array &$form, FormStateInterface $form_state) {
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
        $this->configuration['label'] = $form_state->getValue('label');
    }
    
    /**
     * {@inheritdoc}
     */
    public function access(AccountInterface $account = NULL) {
        return TRUE;
    }

}