src/main/java/org/apache/maven/shared/dependency/analyzer/asm/DefaultClassVisitor.java

package org.apache.maven.shared.dependency.analyzer.asm;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import org.objectweb.asm.*;
import org.objectweb.asm.signature.SignatureReader;
import org.objectweb.asm.signature.SignatureVisitor;


/**
 * Computes the set of classes referenced by visited code.
 * Inspired by <code>org.objectweb.asm.depend.DependencyVisitor</code> in the ASM dependencies example.
 *
 * @author <a href="mailto:markhobson@gmail.com">Mark Hobson</a>
 * @version $Id$
 */
public class DefaultClassVisitor extends ClassVisitor
{
    // fields -----------------------------------------------------------------

    private final ResultCollector resultCollector;

    private final SignatureVisitor signatureVisitor;

    private final AnnotationVisitor annotationVisitor;

    private final FieldVisitor fieldVisitor;

    private final MethodVisitor methodVisitor;

    // constructors -----------------------------------------------------------

    public DefaultClassVisitor(SignatureVisitor signatureVisitor, AnnotationVisitor annotationVisitor, FieldVisitor fieldVisitor, MethodVisitor methodVisitor, ResultCollector resultCollector)
    {
        super(Opcodes.ASM5);
        this.signatureVisitor = signatureVisitor;
        this.annotationVisitor = annotationVisitor;
        this.fieldVisitor = fieldVisitor;
        this.methodVisitor = methodVisitor;
        this.resultCollector = resultCollector;
    }

    public void visit( final int version, final int access, final String name, final String signature,
                       final String superName, final String[] interfaces )
    {
        if ( signature == null )
        {
            resultCollector.addName(superName);
            resultCollector.addNames(interfaces);
        }
        else
        {
            addSignature( signature );
        }
    }

    public AnnotationVisitor visitAnnotation( final String desc, final boolean visible )
    {
        resultCollector.addDesc(desc);
        
        return annotationVisitor;
    }

    public FieldVisitor visitField( final int access, final String name, final String desc, final String signature,
                                    final Object value )
    {
        if ( signature == null )
        {
            resultCollector.addDesc(desc);
        }
        else
        {
            addTypeSignature(signature);
        }

        if ( value instanceof Type )
        {
            resultCollector.addType((Type) value);
        }

        return fieldVisitor;
    }

    public MethodVisitor visitMethod( final int access, final String name, final String desc, final String signature,
                                      final String[] exceptions )
    {
        if ( signature == null )
        {
            resultCollector.addMethodDesc(desc);
        }
        else
        {
            addSignature(signature);
        }

        resultCollector.addNames( exceptions );

        return methodVisitor;
    }


    // private methods --------------------------------------------------------

    private void addSignature( final String signature )
    {
        if ( signature != null )
        {
            new SignatureReader( signature ).accept( signatureVisitor );
        }
    }

    private void addTypeSignature( final String signature )
    {
        if ( signature != null )
        {
            new SignatureReader( signature ).acceptType( signatureVisitor );
        }
    }
}