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.
/***
 * 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 org.objectweb.asm.util;

import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;

An AnnotationVisitor that checks that its methods are properly used. 
Author:
Eric Bruneton/**
 * An {@link AnnotationVisitor} that checks that its methods are properly used.
 * 
 * @author Eric Bruneton
 */
public class CheckAnnotationAdapter extends AnnotationVisitor {

    private final boolean named;

    private boolean end;

    public CheckAnnotationAdapter(final AnnotationVisitor av) {
        this(av, true);
    }

    CheckAnnotationAdapter(final AnnotationVisitor av, final boolean named) {
        super(Opcodes.ASM4, av);
        this.named = named;
    }

    @Override
    public void visit(final String name, final Object value) {
        checkEnd();
        checkName(name);
        if (!(value instanceof Byte || value instanceof Boolean
                || value instanceof Character || value instanceof Short
                || value instanceof Integer || value instanceof Long
                || value instanceof Float || value instanceof Double
                || value instanceof String || value instanceof Type
                || value instanceof byte[] || value instanceof boolean[]
                || value instanceof char[] || value instanceof short[]
                || value instanceof int[] || value instanceof long[]
                || value instanceof float[] || value instanceof double[])) {
            throw new IllegalArgumentException("Invalid annotation value");
        }
        if (value instanceof Type) {
            int sort = ((Type) value).getSort();
            if (sort != Type.OBJECT && sort != Type.ARRAY) {
                throw new IllegalArgumentException("Invalid annotation value");
            }
        }
        if (av != null) {
            av.visit(name, value);
        }
    }

    @Override
    public void visitEnum(final String name, final String desc,
            final String value) {
        checkEnd();
        checkName(name);
        CheckMethodAdapter.checkDesc(desc, false);
        if (value == null) {
            throw new IllegalArgumentException("Invalid enum value");
        }
        if (av != null) {
            av.visitEnum(name, desc, value);
        }
    }

    @Override
    public AnnotationVisitor visitAnnotation(final String name,
            final String desc) {
        checkEnd();
        checkName(name);
        CheckMethodAdapter.checkDesc(desc, false);
        return new CheckAnnotationAdapter(av == null ? null
                : av.visitAnnotation(name, desc));
    }

    @Override
    public AnnotationVisitor visitArray(final String name) {
        checkEnd();
        checkName(name);
        return new CheckAnnotationAdapter(av == null ? null
                : av.visitArray(name), false);
    }

    @Override
    public void visitEnd() {
        checkEnd();
        end = true;
        if (av != null) {
            av.visitEnd();
        }
    }

    private void checkEnd() {
        if (end) {
            throw new IllegalStateException(
                    "Cannot call a visit method after visitEnd has been called");
        }
    }

    private void checkName(final String name) {
        if (named && name == null) {
            throw new IllegalArgumentException(
                    "Annotation value name must not be null");
        }
    }
}