/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file:

 *

 * ASM: a very small and fast Java bytecode manipulation framework

 * Copyright (c) 2000-2011 INRIA, France Telecom

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. Neither the name of the copyright holders nor the names of its

 *    contributors may be used to endorse or promote products derived from

 *    this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF

 * THE POSSIBILITY OF SUCH DAMAGE.

 */

package jdk.internal.org.objectweb.asm;

/**

 * A visitor to visit a Java annotation. The methods of this class must be

 * called in the following order: ( <tt>visit</tt> | <tt>visitEnum</tt> |

 * <tt>visitAnnotation</tt> | <tt>visitArray</tt> )* <tt>visitEnd</tt>.

 *

 * @author Eric Bruneton

 * @author Eugene Kuleshov

 */

public abstract class AnnotationVisitor {

    /**

     * The ASM API version implemented by this visitor. The value of this field

     * must be one of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.

     */

    protected final int api;

    /**

     * The annotation visitor to which this visitor must delegate method calls.

     * May be null.

     */

    protected AnnotationVisitor av;

    /**

     * Constructs a new {@link AnnotationVisitor}.

     *

     * @param api

     *            the ASM API version implemented by this visitor. Must be one

     *            of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.

     */

    public AnnotationVisitor(final int api) {

        this(api, null);

    }

    /**

     * Constructs a new {@link AnnotationVisitor}.

     *

     * @param api

     *            the ASM API version implemented by this visitor. Must be one

     *            of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.

     * @param av

     *            the annotation visitor to which this visitor must delegate

     *            method calls. May be null.

     */

    public AnnotationVisitor(final int api, final AnnotationVisitor av) {

        if (api != Opcodes.ASM4 && api != Opcodes.ASM5) {

            throw new IllegalArgumentException();

        }

        this.api = api;

        this.av = av;

    }

    /**

     * Visits a primitive value of the annotation.

     *

     * @param name

     *            the value name.

     * @param value

     *            the actual value, whose type must be {@link Byte},

     *            {@link Boolean}, {@link Character}, {@link Short},

     *            {@link Integer} , {@link Long}, {@link Float}, {@link Double},

     *            {@link String} or {@link Type} or OBJECT or ARRAY sort. This

     *            value can also be an array of byte, boolean, short, char, int,

     *            long, float or double values (this is equivalent to using

     *            {@link #visitArray visitArray} and visiting each array element

     *            in turn, but is more convenient).

     */

    public void visit(String name, Object value) {

        if (av != null) {

            av.visit(name, value);

        }

    }

    /**

     * Visits an enumeration value of the annotation.

     *

     * @param name

     *            the value name.

     * @param desc

     *            the class descriptor of the enumeration class.

     * @param value

     *            the actual enumeration value.

     */

    public void visitEnum(String name, String desc, String value) {

        if (av != null) {

            av.visitEnum(name, desc, value);

        }

    }

    /**

     * Visits a nested annotation value of the annotation.

     *

     * @param name

     *            the value name.

     * @param desc

     *            the class descriptor of the nested annotation class.

     * @return a visitor to visit the actual nested annotation value, or

     *         <tt>null</tt> if this visitor is not interested in visiting this

     *         nested annotation. <i>The nested annotation value must be fully

     *         visited before calling other methods on this annotation

     *         visitor</i>.

     */

    public AnnotationVisitor visitAnnotation(String name, String desc) {

        if (av != null) {

            return av.visitAnnotation(name, desc);

        }

        return null;

    }

    /**

     * Visits an array value of the annotation. Note that arrays of primitive

     * types (such as byte, boolean, short, char, int, long, float or double)

     * can be passed as value to {@link #visit visit}. This is what

     * {@link ClassReader} does.

     *

     * @param name

     *            the value name.

     * @return a visitor to visit the actual array value elements, or

     *         <tt>null</tt> if this visitor is not interested in visiting these

     *         values. The 'name' parameters passed to the methods of this

     *         visitor are ignored. <i>All the array values must be visited

     *         before calling other methods on this annotation visitor</i>.

     */

    public AnnotationVisitor visitArray(String name) {

        if (av != null) {

            return av.visitArray(name);

        }

        return null;

    }

    /**

     * Visits the end of the annotation.

     */

    public void visitEnd() {

        if (av != null) {

            av.visitEnd();

        }

    }

}