001 /*
002 * Copyright 2005-2006 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package javax.lang.model.util;
027
028 import javax.lang.model.type.*;
029 import javax.annotation.processing.SupportedSourceVersion;
030 import javax.lang.model.SourceVersion;
031 import static javax.lang.model.SourceVersion.*;
032
033 /**
034 * A simple visitor of types with default behavior appropriate for the
035 * {@link SourceVersion#RELEASE_6 RELEASE_6} source version.
036 *
037 * Visit methods corresponding to {@code RELEASE_6} language
038 * constructs call {@link #defaultAction}, passing their arguments to
039 * {@code defaultAction}'s corresponding parameters.
040 *
041 * <p> Methods in this class may be overridden subject to their
042 * general contract. Note that annotating methods in concrete
043 * subclasses with {@link java.lang.Override @Override} will help
044 * ensure that methods are overridden as intended.
045 *
046 * <p> <b>WARNING:</b> The {@code TypeVisitor} interface implemented
047 * by this class may have methods added to it in the future to
048 * accommodate new, currently unknown, language structures added to
049 * future versions of the Java™ programming language.
050 * Therefore, methods whose names begin with {@code "visit"} may be
051 * added to this class in the future; to avoid incompatibilities,
052 * classes which extend this class should not declare any instance
053 * methods with names beginning with {@code "visit"}.
054 *
055 * <p>When such a new visit method is added, the default
056 * implementation in this class will be to call the {@link
057 * #visitUnknown visitUnknown} method. A new simple type visitor
058 * class will also be introduced to correspond to the new language
059 * level; this visitor will have different default behavior for the
060 * visit method in question. When the new visitor is introduced, all
061 * or portions of this visitor may be deprecated.
062 *
063 * @param <R> the return type of this visitor's methods. Use {@link
064 * Void} for visitors that do not need to return results.
065 * @param <P> the type of the additional parameter to this visitor's
066 * methods. Use {@code Void} for visitors that do not need an
067 * additional parameter.
068 *
069 * @author Joseph D. Darcy
070 * @author Scott Seligman
071 * @author Peter von der Ahé
072 * @version 1.13 07/05/05
073 * @since 1.6
074 */
075 @SupportedSourceVersion(RELEASE_6)
076 public class SimpleTypeVisitor6<R, P> extends
077 AbstractTypeVisitor6<R, P> {
078 /**
079 * Default value to be returned; {@link #defaultAction
080 * defaultAction} returns this value unless the method is
081 * overridden.
082 */
083 protected final R DEFAULT_VALUE;
084
085 /**
086 * Constructor for concrete subclasses; uses {@code null} for the
087 * default value.
088 */
089 protected SimpleTypeVisitor6() {
090 DEFAULT_VALUE = null;
091 }
092
093 /**
094 * Constructor for concrete subclasses; uses the argument for the
095 * default value.
096 *
097 * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}
098 */
099 protected SimpleTypeVisitor6(R defaultValue) {
100 DEFAULT_VALUE = defaultValue;
101 }
102
103 /**
104 * The default action for visit methods. The implementation in
105 * this class just returns {@link #DEFAULT_VALUE}; subclasses will
106 * commonly override this method.
107 */
108 protected R defaultAction(TypeMirror e, P p) {
109 return DEFAULT_VALUE;
110 }
111
112 /**
113 * {@inheritDoc} This implementation calls {@code defaultAction}.
114 *
115 * @param t {@inheritDoc}
116 * @param p {@inheritDoc}
117 * @return the result of {@code defaultAction}
118 */
119 public R visitPrimitive(PrimitiveType t, P p) {
120 return defaultAction(t, p);
121 }
122
123 /**
124 * {@inheritDoc} This implementation calls {@code defaultAction}.
125 *
126 * @param t {@inheritDoc}
127 * @param p {@inheritDoc}
128 * @return the result of {@code defaultAction}
129 */
130 public R visitNull(NullType t, P p) {
131 return defaultAction(t, p);
132 }
133
134 /**
135 * {@inheritDoc} This implementation calls {@code defaultAction}.
136 *
137 * @param t {@inheritDoc}
138 * @param p {@inheritDoc}
139 * @return the result of {@code defaultAction}
140 */
141 public R visitArray(ArrayType t, P p) {
142 return defaultAction(t, p);
143 }
144
145 /**
146 * {@inheritDoc} This implementation calls {@code defaultAction}.
147 *
148 * @param t {@inheritDoc}
149 * @param p {@inheritDoc}
150 * @return the result of {@code defaultAction}
151 */
152 public R visitDeclared(DeclaredType t, P p) {
153 return defaultAction(t, p);
154 }
155
156 /**
157 * {@inheritDoc} This implementation calls {@code defaultAction}.
158 *
159 * @param t {@inheritDoc}
160 * @param p {@inheritDoc}
161 * @return the result of {@code defaultAction}
162 */
163 public R visitError(ErrorType t, P p) {
164 return defaultAction(t, p);
165 }
166
167 /**
168 * {@inheritDoc} This implementation calls {@code defaultAction}.
169 *
170 * @param t {@inheritDoc}
171 * @param p {@inheritDoc}
172 * @return the result of {@code defaultAction}
173 */
174 public R visitTypeVariable(TypeVariable t, P p) {
175 return defaultAction(t, p);
176 }
177
178 /**
179 * {@inheritDoc} This implementation calls {@code defaultAction}.
180 *
181 * @param t {@inheritDoc}
182 * @param p {@inheritDoc}
183 * @return the result of {@code defaultAction}
184 */
185 public R visitWildcard(WildcardType t, P p) {
186 return defaultAction(t, p);
187 }
188
189 /**
190 * {@inheritDoc} This implementation calls {@code defaultAction}.
191 *
192 * @param t {@inheritDoc}
193 * @param p {@inheritDoc}
194 * @return the result of {@code defaultAction}
195 */
196 public R visitExecutable(ExecutableType t, P p) {
197 return defaultAction(t, p);
198 }
199
200 /**
201 * {@inheritDoc} This implementation calls {@code defaultAction}.
202 *
203 * @param t {@inheritDoc}
204 * @param p {@inheritDoc}
205 * @return the result of {@code defaultAction}
206 */
207 public R visitNoType(NoType t, P p) {
208 return defaultAction(t, p);
209 }
210 }
|