001package ball.annotation.processing;
002/*-
003 * ##########################################################################
004 * Utilities
005 * $Id: TargetMustHaveModifiers.java 6099 2020-06-03 17:01:31Z ball $
006 * $HeadURL: svn+ssh://svn.hcf.dev/var/spool/scm/repository.svn/ball-util/trunk/src/main/java/ball/annotation/processing/TargetMustHaveModifiers.java $
007 * %%
008 * Copyright (C) 2008 - 2020 Allen D. Ball
009 * %%
010 * Licensed under the Apache License, Version 2.0 (the "License");
011 * you may not use this file except in compliance with the License.
012 * You may obtain a copy of the License at
013 *
014 *      http://www.apache.org/licenses/LICENSE-2.0
015 *
016 * Unless required by applicable law or agreed to in writing, software
017 * distributed under the License is distributed on an "AS IS" BASIS,
018 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
019 * See the License for the specific language governing permissions and
020 * limitations under the License.
021 * ##########################################################################
022 */
023import ball.annotation.ServiceProviderFor;
024import java.lang.annotation.Documented;
025import java.lang.annotation.Retention;
026import java.lang.annotation.Target;
027import javax.annotation.processing.Processor;
028import javax.annotation.processing.RoundEnvironment;
029import javax.lang.model.element.AnnotationMirror;
030import javax.lang.model.element.AnnotationValue;
031import javax.lang.model.element.Element;
032import javax.lang.model.element.Modifier;
033import javax.lang.model.element.TypeElement;
034import lombok.NoArgsConstructor;
035import lombok.ToString;
036
037import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
038import static java.lang.annotation.RetentionPolicy.RUNTIME;
039import static javax.tools.Diagnostic.Kind.ERROR;
040
041/**
042 * {@link java.lang.annotation.Annotation} to specify {@link Modifier}s an
043 * annotated {@link Element} must extend.
044 *
045 * @see AnnotatedProcessor
046 *
047 * @author {@link.uri mailto:ball@hcf.dev Allen D. Ball}
048 * @version $Revision: 6099 $
049 */
050@Documented
051@Retention(RUNTIME)
052@Target(ANNOTATION_TYPE)
053public @interface TargetMustHaveModifiers {
054    Modifier[] value();
055
056    /**
057     * {@link Processor} implementation.
058     */
059    @ServiceProviderFor({ Processor.class })
060    @For({ TargetMustHaveModifiers.class })
061    @NoArgsConstructor @ToString
062    public static class ProcessorImpl extends AnnotatedProcessor {
063        @Override
064        public void process(RoundEnvironment roundEnv,
065                            TypeElement annotation, Element element) {
066            super.process(roundEnv, annotation, element);
067
068            AnnotationMirror mirror = getAnnotationMirror(element, annotation);
069            AnnotationValue value = getAnnotationValue(mirror, "value");
070
071            if (isEmptyArray(value)) {
072                print(ERROR, element, mirror, value, "value() is empty");
073            }
074        }
075    }
076}