/*
 * @(#)AttributeInfo.java	1.4 95/08/16 Chuck McManis
 *
 * Copyright (c) 1996 Chuck McManis, All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL purposes and without
 * fee is hereby granted provided that this copyright notice
 * appears in all copies.
 *
 * CHUCK MCMANIS MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY
 * OF THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. CHUCK MCMANIS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING,
 * MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 */

package util;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;

/**
 * This class defines the generic Attribute type for Java class files.
 * It is a little bit smart in that for some Attributes it can display
 * them intelligently if it also has access to the constant pool of the
 * current class.
 *
 * @version 	1.4, 16 Aug 1995
 * @author	Chuck McManis
 * @see		ClassFile
 */
public class AttributeInfo {
    ConstantPoolInfo	name;	// attribute name
    byte		data[]; // attribute's contents

    public AttributeInfo(ConstantPoolInfo newName, byte newData[]) {
	name = name;
	data = newData;
    }

    public AttributeInfo() {
    }

    public boolean read(DataInputStream di, ConstantPoolInfo pool[])
	throws IOException {
	int len;

	name = pool[di.readShort()];
	len = di.readInt();
	data = new byte[len];
	len  = di.read(data);
	if (len != data.length)
	    return (false);
	return (true);
    }

    public void write(DataOutputStream dos, ConstantPoolInfo pool[])
	throws IOException, Exception {
	dos.writeShort(ConstantPoolInfo.indexOf(name, pool));
	dos.writeInt(data.length);
	dos.write(data, 0, data.length);
    }

    short indexFromBytes(byte a[]) {
	return (short)(((a[0] << 8) & (0xff << 8)) |
		       ((a[1] << 0) & (0xff << 0)));
    }

    public String toString(ConstantPoolInfo pool[]) {
	StringBuffer x = new StringBuffer();
	String type = name.toString();
	ConstantPoolInfo item;

	if (type.compareTo("ConstantValue") == 0) {
	    item = pool[indexFromBytes(data)];
	    return (item.toString());
	} else if (type.compareTo("SourceFile") == 0) {
	    item = pool[indexFromBytes(data)];
	    return (item.toString());
	} else {
	    x.append(type+"<"+data.length+" bytes>");
	}
	return (x.toString());
    }

    public String toBoolean(ConstantPoolInfo pool[]) {
	ConstantPoolInfo item = pool[indexFromBytes(data)];

	if (item.intValue == 0)
	    return ("= false");
	return ("= true");
    }

    public String toString() {
	return (name.toString()+" <"+data.length+" bytes>");
    }
}