/*
 * Copyright  2000-2004 The Apache Software Foundation
 *
 *  Licensed 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. 
 *
 */
package org.apache.bcel.classfile;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import org.apache.bcel.Constants;

/**
 * This class is derived from <em>Attribute</em> and denotes that this class
 * is an Inner class of another.
 * to the source file of this class.
 * It is instantiated from the <em>Attribute.readAttribute()</em> method.
 *
 * @version $Id: InnerClasses.java 386056 2006-03-15 11:31:56Z tcurdt $
 * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
 * @see     Attribute
 */
public final class InnerClasses extends Attribute {

    private InnerClass[] inner_classes;
    private int number_of_classes;


    /**
     * Initialize from another object. Note that both objects use the same
     * references (shallow copy). Use clone() for a physical copy.
     */
    public InnerClasses(InnerClasses c) {
        this(c.getNameIndex(), c.getLength(), c.getInnerClasses(), c.getConstantPool());
    }


    /**
     * @param name_index Index in constant pool to CONSTANT_Utf8
     * @param length Content length in bytes
     * @param inner_classes array of inner classes attributes
     * @param constant_pool Array of constants
     */
    public InnerClasses(int name_index, int length, InnerClass[] inner_classes,
            ConstantPool constant_pool) {
        super(Constants.ATTR_INNER_CLASSES, name_index, length, constant_pool);
        setInnerClasses(inner_classes);
    }


    /**
     * Construct object from file stream.
     *
     * @param name_index Index in constant pool to CONSTANT_Utf8
     * @param length Content length in bytes
     * @param file Input stream
     * @param constant_pool Array of constants
     * @throws IOException
     */
    InnerClasses(int name_index, int length, DataInputStream file, ConstantPool constant_pool)
            throws IOException {
        this(name_index, length, (InnerClass[]) null, constant_pool);
        number_of_classes = file.readUnsignedShort();
        inner_classes = new InnerClass[number_of_classes];
        for (int i = 0; i < number_of_classes; i++) {
            inner_classes[i] = new InnerClass(file);
        }
    }


    /**
     * Called by objects that are traversing the nodes of the tree implicitely
     * defined by the contents of a Java class. I.e., the hierarchy of methods,
     * fields, attributes, etc. spawns a tree of objects.
     *
     * @param v Visitor object
     */
    public void accept( Visitor v ) {
        v.visitInnerClasses(this);
    }


    /**
     * Dump source file attribute to file stream in binary format.
     *
     * @param file Output file stream
     * @throws IOException
     */
    public final void dump( DataOutputStream file ) throws IOException {
        super.dump(file);
        file.writeShort(number_of_classes);
        for (int i = 0; i < number_of_classes; i++) {
            inner_classes[i].dump(file);
        }
    }


    /**
     * @return array of inner class "records"
     */
    public final InnerClass[] getInnerClasses() {
        return inner_classes;
    }


    /**
     * @param inner_classes the array of inner classes
     */
    public final void setInnerClasses( InnerClass[] inner_classes ) {
        this.inner_classes = inner_classes;
        number_of_classes = (inner_classes == null) ? 0 : inner_classes.length;
    }


    /**
     * @return String representation.
     */
    public final String toString() {
        StringBuffer buf = new StringBuffer();
        for (int i = 0; i < number_of_classes; i++) {
            buf.append(inner_classes[i].toString(constant_pool)).append("\n");
        }
        return buf.toString();
    }


    /**
     * @return deep copy of this attribute
     */
    public Attribute copy( ConstantPool _constant_pool ) {
        InnerClasses c = (InnerClasses) clone();
        c.inner_classes = new InnerClass[number_of_classes];
        for (int i = 0; i < number_of_classes; i++) {
            c.inner_classes[i] = inner_classes[i].copy();
        }
        c.constant_pool = _constant_pool;
        return c;
    }
}
