001package org.apache.tapestry5.internal.plastic;
002
003import java.lang.annotation.Annotation;
004import java.lang.annotation.Inherited;
005
006import org.apache.tapestry5.plastic.AnnotationAccess;
007
008/**
009 * Delegating annotation access is used when resolving annotations on a class; it searches the primary
010 * annotation access and if not found there (and {@link Inherited} is on the annotation being searched),
011 * it searches in the inherited access.
012 */
013public class DelegatingAnnotationAccess implements AnnotationAccess
014{
015    private final AnnotationAccess primary;
016
017    private final AnnotationAccess inherited;
018
019    public DelegatingAnnotationAccess(AnnotationAccess primary, AnnotationAccess inherited)
020    {
021        this.primary = primary;
022        this.inherited = inherited;
023    }
024
025    private boolean isInherited(Class<? extends Annotation> annotationType)
026    {
027        return annotationType.getAnnotation(Inherited.class) != null;
028    }
029
030    public <T extends Annotation> boolean hasAnnotation(Class<T> annotationType)
031    {
032        if (primary.hasAnnotation(annotationType))
033            return true;
034
035        return isInherited(annotationType) && inherited.hasAnnotation(annotationType);
036    }
037
038    public <T extends Annotation> T getAnnotation(Class<T> annotationType)
039    {
040        T fromPrimary = primary.getAnnotation(annotationType);
041
042        if (fromPrimary != null)
043            return fromPrimary;
044
045        return isInherited(annotationType) ? inherited.getAnnotation(annotationType) : null;
046    }
047}