/*
 * 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.
 */

package org.apache.bcel.classfile;

import java.io.DataInput;
import java.io.DataOutputStream;
import java.io.IOException;

import org.apache.bcel.Const;

This class is derived from Attribute and records the classes and interfaces that
are authorized to claim membership in the nest hosted by the current class or interface.
There may be at most one NestMembers attribute in a ClassFile structure.
See Also:
Attribute/**
 * This class is derived from <em>Attribute</em> and records the classes and interfaces that
 * are authorized to claim membership in the nest hosted by the current class or interface.
 * There may be at most one NestMembers attribute in a ClassFile structure.
 *
 * @see     Attribute
 */
public final class NestMembers extends Attribute {

    private int[] classes;


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


    
Params:
name_index – Index in constant pool
length – Content length in bytes
classes – Table of indices in constant pool
constant_pool – Array of constants/**
     * @param name_index Index in constant pool
     * @param length Content length in bytes
     * @param classes Table of indices in constant pool
     * @param constant_pool Array of constants
     */
    public NestMembers(final int name_index, final int length, final int[] classes,
            final ConstantPool constant_pool) {
        super(Const.ATTR_NEST_MEMBERS, name_index, length, constant_pool);
        this.classes = classes != null ? classes : new int[0];
    }


    
Construct object from input stream.
Params:
name_index – Index in constant pool
length – Content length in bytes
input – Input stream
constant_pool – Array of constants
Throws:
IOException – /**
     * Construct object from input stream.
     * @param name_index Index in constant pool
     * @param length Content length in bytes
     * @param input Input stream
     * @param constant_pool Array of constants
     * @throws IOException
     */
    NestMembers(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool) throws IOException {
        this(name_index, length, (int[]) null, constant_pool);
        final int number_of_classes = input.readUnsignedShort();
        classes = new int[number_of_classes];
        for (int i = 0; i < number_of_classes; i++) {
            classes[i] = input.readUnsignedShort();
        }
    }


    
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.
Params:
v – Visitor object/**
     * 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
     */
    @Override
    public void accept( final Visitor v ) {
        v.visitNestMembers(this);
    }


    
Dump NestMembers attribute to file stream in binary format.
Params:
file – Output file stream
Throws:
IOException – /**
     * Dump NestMembers attribute to file stream in binary format.
     *
     * @param file Output file stream
     * @throws IOException
     */
    @Override
    public void dump( final DataOutputStream file ) throws IOException {
        super.dump(file);
        file.writeShort(classes.length);
        for (final int index : classes) {
            file.writeShort(index);
        }
    }


    
Returns:
array of indices into constant pool of class names./**
     * @return array of indices into constant pool of class names.
     */
    public int[] getClasses() {
        return classes;
    }


    
Returns:
Length of classes table./**
     * @return Length of classes table.
     */
    public int getNumberClasses() {
        return classes == null ? 0 : classes.length;
    }


    
Returns:
string array of class names/**
     * @return string array of class names
     */
    public String[] getClassNames() {
        final String[] names = new String[classes.length];
        for (int i = 0; i < classes.length; i++) {
            names[i] = super.getConstantPool().getConstantString(classes[i],
                    Const.CONSTANT_Class).replace('/', '.');
        }
        return names;
    }


    
Params:
classes – the list of class indexes
Also redefines number_of_classes according to table length./**
     * @param classes the list of class indexes
     * Also redefines number_of_classes according to table length.
     */
    public void setClasses( final int[] classes ) {
        this.classes = classes != null ? classes : new int[0];
    }


    
Returns:
String representation, i.e., a list of classes./**
     * @return String representation, i.e., a list of classes.
     */
    @Override
    public String toString() {
        final StringBuilder buf = new StringBuilder();
        buf.append("NestMembers(");
        buf.append(classes.length);
        buf.append("):\n");
        for (final int index : classes) {
            final String class_name = super.getConstantPool().getConstantString(index, Const.CONSTANT_Class);
            buf.append("  ").append(Utility.compactClassName(class_name, false)).append("\n");
        }
        return buf.substring(0, buf.length()-1); // remove the last newline
    }


    
Returns:
deep copy of this attribute/**
     * @return deep copy of this attribute
     */
    @Override
    public Attribute copy( final ConstantPool _constant_pool ) {
        final NestMembers c = (NestMembers) clone();
        if (classes != null) {
            c.classes = new int[classes.length];
            System.arraycopy(classes, 0, c.classes, 0,
                    classes.length);
        }
        c.setConstantPool(_constant_pool);
        return c;
    }
}