001/* -*- mode: Java; c-basic-offset: 2; indent-tabs-mode: nil; coding: utf-8-unix -*-
002 *
003 * Copyright © 2018 microBean.
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
014 * implied.  See the License for the specific language governing
015 * permissions and limitations under the License.
016 */
017package org.microbean.kubernetes.controller.cdi.annotation;
018
019import java.lang.annotation.Documented;
020import java.lang.annotation.ElementType;
021import java.lang.annotation.Retention;
022import java.lang.annotation.RetentionPolicy;
023import java.lang.annotation.Target;
024
025import javax.inject.Qualifier;
026
027import javax.enterprise.util.AnnotationLiteral;
028
029/**
030 * A {@link Qualifier} that can be used only on an observer method's
031 * <a
032 * href="http://docs.jboss.org/cdi/spec/2.0/cdi-spec.html#observer_method_event_parameter">event
033 * parameter</a> that is also annotated with an annotation annotated
034 * with {@link KubernetesEventSelector}, thus indicating that the
035 * observer method is interested in being notified of the
036 * <em>addition</em> of certain Kubernetes resources.
037 *
038 * @author <a href="https://about.me/lairdnelson"
039 * target="_parent">Laird Nelson</a>
040 *
041 * @see KubernetesEventSelector
042 */
043@Documented
044@Qualifier
045@Retention(value = RetentionPolicy.RUNTIME)
046@Target({ ElementType.PARAMETER })
047public @interface Added {
048
049  /**
050   * Whether the observer method should be notified in the case of
051   * <em>synchronization events</em>.
052   *
053   * @return true if the observer method should be notified in the case of
054   * <em>synchronization events</em>, {@code false} otherwise
055   */
056  boolean synchronization() default false;
057
058
059  /*
060   * Inner and nested classes.
061   */
062
063
064  /**
065   * An {@link AnnotationLiteral} that implements {@link Added}.
066   *
067   * @author <a href="https://about.me/lairdnelson"
068   * target="_parent">Laird Nelson</a>
069   */
070  public static final class Literal extends AnnotationLiteral<Added> implements Added {
071
072
073    /*
074     * Static fields.
075     */
076
077
078    private static final long serialVersionUID = 1L;
079
080    private static final Added WITH_SYNCHRONIZATION = new Literal(true);
081
082    private static final Added WITHOUT_SYNCHRONIZATION = new Literal(false);
083
084
085    /*
086     * Instance fields.
087     */
088
089
090    private final boolean synchronization;
091
092
093    /*
094     * Constructors.
095     */
096
097
098    private Literal(final boolean synchronization) {
099      super();
100      this.synchronization = synchronization;
101    }
102
103
104    /*
105     * Instance methods.
106     */
107
108
109    /**
110     * Whether the observer method should be notified in the case of
111     * <em>synchronization events</em>.
112     *
113     * @return true if the observer method should be notified in the case of
114     * <em>synchronization events</em>, {@code false} otherwise
115     */
116    @Override
117    public final boolean synchronization() {
118      return this.synchronization;
119    }
120
121
122    /*
123     * Static methods.
124     */
125
126
127    /**
128     * Returns an {@link Added} instance whose {@link
129     * #synchronization() synchronization} element is {@code true}.
130     *
131     * <p>This method never returns {@code null}.</p>
132     *
133     * @return a non-{@code null} {@link Added}
134     */
135    public static Added withSynchronization() {
136      return WITH_SYNCHRONIZATION;
137    }
138
139    /**
140     * Returns an {@link Added} instance whose {@link
141     * #synchronization() synchronization} element is {@code false}.
142     *
143     * <p>This method never returns {@code null}.</p>
144     *
145     * @return a non-{@code null} {@link Added}
146     */
147    public static Added withoutSynchronization() {
148      return WITHOUT_SYNCHRONIZATION;
149    }
150
151  }
152
153}