/*
 * $Id: ZCharDecoder.java 536 2008-02-19 06:03:27Z weiju $
 * 
 * Created on 2005/09/23
 * Copyright 2005-2008 by Wei-ju Wu
 * This file is part of The Z-machine Preservation Project (ZMPP).
 *
 * ZMPP is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * ZMPP is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with ZMPP.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.zmpp.encoding;

import org.zmpp.base.Memory;

/**
 * This interface provides decoding for the Z character encoding into the Java
 * character system. It is important to point out that there is a difference
 * between Z characters and the ZCSII encoding. Where ZSCII is a character set
 * that is similar to ASCII/iso-8859-1, the Z characters are a encoded form of
 * characters in memory that provide some degree of compression and encryption.
 *
 * ZCharConverter uses the alphabet tables specified in the Z machine standards
 * document 1.0, section 3.
 *
 * @author Wei-ju Wu
 * @version 1.0
 */
public interface ZCharDecoder {

    /**
     * This interface defines the abstract access to an abbreviations table in
     * memory, this will be used for decoding if needed.
     */
    public interface AbbreviationsTable {

        int getWordAddress(int entryNum);
    }

    /**
     * Performs a ZSCII decoding at the specified position of the given memory
     * object, this method is exclusively designed to deal with the problems of
     * dictionary entries. These can be cropped, leaving the string in a state,
     * that can not be decoded properly otherwise. If the provided length is 0,
     * the semantics are equal to the method without the length parameter.
     *
     * @param memory a Memory object
     * @param address the address of the string
     * @param length the maximum length in bytes
     * @return the decoded string
     */
    ZsciiString decode2Zscii(Memory memory, int address, int length);

    /**
     * Decodes the given byte value to the specified buffer using the working
     * alphabet.
     *
     * @param zchar a z encoded character, needs to be a non-shift character
     */
    char decodeZChar(char zchar);

    /**
     * Returns the ZStringTranslator.
     *
     * @return the translator
     */
    ZCharTranslator getTranslator();
}