/*

 * Copyright 1996-2002 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package sun.io;

/**

 * A table driven conversion from byte to char for single byte  character sets.

 * The needed data tables will reside in a character set specific subclass.

 *

 * @author Lloyd Honomichl

 * @author Asmus Freytag

 */

public abstract class ByteToCharSingleByte extends ByteToCharConverter {

    /**

     * Mapping table. Values supplied by subclass

     */

    protected String byteToCharTable;

    public String getByteToCharTable() {

        return byteToCharTable;

    }

    public int flush(char[] output, int outStart, int outEnd) {

        byteOff = charOff = 0;

        return 0;

    }

    /**

     * Converts bytes to characters according to the selected character

     * encoding.

     * Maintains internal state, so that conversions that result in

     * exceptions can be restarted by calling convert again, with

     * appropriately modified parameters.

     * Call reset before converting input that is not a continuation of

     * the previous call.

     * @return the number of characters written to output.

     * @param input byte array containing text in character set

     * @param inStart offset in input array

     * @param inEnd offset of last byte to be converted

     * @param output character array to receive conversion result

     * @param outStart starting offset

     * @param outEnd offset of last character to be written to

     * @throw MalformedInputException for any sequence of bytes that is

     * illegal for the input character set, including any partial multi-byte

     * sequence which occurs at the end of an input buffer.

     * @throw UnsupportedCharacterException for any sequence of bytes that

     * contain a character not supported in the current conversion.

     * @throw BufferFullException whenever the output buffer is full

     * before the input is exhausted.

     * @see #reset

     */

    public int convert(byte[] input, int inOff, int inEnd,

                       char[] output, int outOff, int outEnd)

        throws UnknownCharacterException,

               MalformedInputException,

               ConversionBufferFullException

    {

        char    outputChar;

        int     byteIndex;

        charOff = outOff;

        byteOff = inOff;

        // Loop until we hit the end of the input

        while(byteOff < inEnd) {

            byteIndex = input[byteOff];

            /* old source

             *outputChar = byteToCharTable[input[byteOff] + 128];

             */

            // Lookup the output character

            outputChar = getUnicode(byteIndex);

            // Is the output unmappable?

            if (outputChar == '\uFFFD') {

                if (subMode) {

                    outputChar = subChars[0];

                } else {

                    badInputLength = 1;

                    throw new UnknownCharacterException();

                }

            }

            // If we don't have room for the output, throw an exception

            if (charOff >= outEnd)

                throw new ConversionBufferFullException();

            // Put the character in the output buffer

            output[charOff]= outputChar;

            charOff++;

            byteOff++;

        }

        // Return the length written to the output buffer

        return charOff-outOff;

    }

    protected char getUnicode(int byteIndex) {

        int n = byteIndex + 128;

        if (n >= byteToCharTable.length() || n < 0)

            return '\uFFFD';

        return byteToCharTable.charAt(n);

    }

    /**

     *  Resets the converter.

     *  Call this method to reset the converter to its initial state

     */

    public void reset() {

        byteOff = charOff = 0;

    }

}