package org.trails.descriptor.annotation;

 import org.apache.commons.lang.Validate;

 import org.trails.descriptor.IPropertyDescriptor;

 /**

  * Creates a {@link InitialValueDescriptorExtension} using the

  * information retrieved from a {@link InitialValue} annotation.

  *

  * @author pruggia

  */

 public class InitialValueAnnotationHandler extends AbstractAnnotationHandler

                 implements DescriptorAnnotationHandler<InitialValue, IPropertyDescriptor>

 {

         /**

          * Creates a {@link InitialValueDescriptorExtension} and adds it to

          * the property descriptor.

          *

          * @param annotation Annotation added to the property. It cannot be null.

          * @param descriptor The property descriptor. It cannot be null.

          * @return The provided descriptor with the extension added.

          */

         public IPropertyDescriptor decorateFromAnnotation(final InitialValue annotation,

                                                                                                           final IPropertyDescriptor descriptor)

         {

                 Validate.notNull(annotation, "The annotation cannot be null");

                 Validate.notNull(descriptor, "The descriptor cannot be null");

                 InitialValueDescriptorExtension extension = new InitialValueDescriptorExtension(annotation.value());

                 descriptor.addExtension(InitialValueDescriptorExtension.class

                                 .getName(), extension);

                 return descriptor;

         }

 }