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/* * @(#)SimpleElementVisitor6.java 1.7 06/08/15 * * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */ package javax.lang.model.util; import javax.lang.model.element.*; import javax.annotation.processing.SupportedSourceVersion; import static javax.lang.model.element.ElementKind.*; import javax.lang.model.SourceVersion; import static javax.lang.model.SourceVersion.*; /** * A simple visitor of program elements with default behavior * appropriate for the {@link SourceVersion#RELEASE_6 RELEASE_6} * source version. * * Visit methods corresponding to {@code RELEASE_6} language * constructs call {@link #defaultAction}, passing their arguments to * {@code defaultAction}'s corresponding parameters. * * <p> Methods in this class may be overridden subject to their * general contract. Note that annotating methods in concrete * subclasses with {@link java.lang.Override @Override} will help * ensure that methods are overridden as intended. * * <p> <b>WARNING:</b> The {@code ElementVisitor} interface * implemented by this class may have methods added to it in the * future to accommodate new, currently unknown, language structures * added to future versions of the Java™ programming language. * Therefore, methods whose names begin with {@code "visit"} may be * added to this class in the future; to avoid incompatibilities, * classes which extend this class should not declare any instance * methods with names beginning with {@code "visit"}. * * <p>When such a new visit method is added, the default * implementation in this class will be to call the {@link * #visitUnknown visitUnknown} method. A new simple element visitor * class will also be introduced to correspond to the new language * level; this visitor will have different default behavior for the * visit method in question. When the new visitor is introduced, all * or portions of this visitor may be deprecated. * * @param <R> the return type of this visitor's methods. Use {@code Void} * for visitors that do not need to return results. * @param <P> the type of the additional parameter to this visitor's methods. Use {@code Void} * for visitors that do not need an additional parameter. * * @author Joseph D. Darcy * @author Scott Seligman * @author Peter von der Ahé * @version 1.7 06/08/15 * @since 1.6 */ @SupportedSourceVersion(RELEASE_6) public class SimpleElementVisitor6<R, P> extends AbstractElementVisitor6<R, P> { /** * Default value to be returned; {@link #defaultAction * defaultAction} returns this value unless the method is * overridden. */ protected final R DEFAULT_VALUE; /** * Constructor for concrete subclasses; uses {@code null} for the * default value. */ protected SimpleElementVisitor6(){ DEFAULT_VALUE = null; } /** * Constructor for concrete subclasses; uses the argument for the * default value. * * @param defaultValue the value to assign to {@link #DEFAULT_VALUE} */ protected SimpleElementVisitor6(R defaultValue){ DEFAULT_VALUE = defaultValue; } /** * The default action for visit methods. The implementation in * this class just returns {@link #DEFAULT_VALUE}; subclasses will * commonly override this method. * * @param e the element to process * @param p a visitor-specified parameter * @return {@code DEFAULT_VALUE} unless overridden */ protected R defaultAction(Element e, P p) { return DEFAULT_VALUE; } /** * {@inheritDoc} This implementation calls {@code defaultAction}. * * @param e {@inheritDoc} * @param p {@inheritDoc} * @return the result of {@code defaultAction} */ public R visitPackage(PackageElement e, P p) { return defaultAction(e, p); } /** * {@inheritDoc} This implementation calls {@code defaultAction}. * * @param e {@inheritDoc} * @param p {@inheritDoc} * @return the result of {@code defaultAction} */ public R visitType(TypeElement e, P p) { return defaultAction(e, p); } /** * {@inheritDoc} This implementation calls {@code defaultAction}. * * @param e {@inheritDoc} * @param p {@inheritDoc} * @return the result of {@code defaultAction} */ public R visitVariable(VariableElement e, P p) { return defaultAction(e, p); } /** * {@inheritDoc} This implementation calls {@code defaultAction}. * * @param e {@inheritDoc} * @param p {@inheritDoc} * @return the result of {@code defaultAction} */ public R visitExecutable(ExecutableElement e, P p) { return defaultAction(e, p); } /** * {@inheritDoc} This implementation calls {@code defaultAction}. * * @param e {@inheritDoc} * @param p {@inheritDoc} * @return the result of {@code defaultAction} */ public R visitTypeParameter(TypeParameterElement e, P p) { return defaultAction(e, p); } }