Subversion Repositories display

/*
 * Copyright (C) 2015 Steve Ratcliffe
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3 or
 * version 2 as published by the Free Software Foundation.
 *
 * This program 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.
 */
package test.files;

import java.io.IOException;

import uk.me.parabola.imgfmt.ReadFailedException;
import uk.me.parabola.imgfmt.app.ImgFileReader;


public class ByteImgFileReader implements ImgFileReader {
        private final byte[] bytes;
        private int offset;

        public ByteImgFileReader(byte[] bytes) {
                this.bytes = bytes;
        }

        /**
         * Get the position.  Needed because may not be reflected in the underlying
         * file if being buffered.
         *
         * @return The logical position within the file.
         */
        @Override
        public long position() {
                return offset;
        }

        /**
         * Set the position of the file.
         *
         * @param pos The new position in the file.
         */
        @Override
        public void position(long pos) {
                offset = (int) pos;
        }

        /**
         * Read in a single byte.
         *
         * @return The byte that was read.
         */
        @Override
        public byte get() throws ReadFailedException {
                return bytes[offset++];
        }

        @Override
        public int get1u() throws ReadFailedException {
                return bytes[offset++] & 0xff;
        }

        @Override
        public int get1s() throws ReadFailedException {
                return bytes[offset++];
        }

        /**
         * Read in two bytes.  Done in the correct byte order.
         *
         * @return The 2 byte integer that was read.
         */
        @Override
        public int get2u() throws ReadFailedException {
                byte b1 = bytes[offset++];
                byte b2 = bytes[offset++];
                return (char) (((b2 & 0xff) << 8) + (b1 & 0xff));
        }

        @Override
        public int get2s() throws ReadFailedException {
                byte b1 = bytes[offset++];
                byte b2 = bytes[offset++];
                return (b2 << 8) | (b1 & 0xff);
        }

        /**
         * Get a 3byte signed quantity.
         *
         * @return The value read.
         * @throws ReadFailedException When the file cannot be read.
         */
        @Override
        public int get3s() throws ReadFailedException {
                int val = get3u();
                if ((val & 0x800000) != 0)
                        val |= 0xff000000;
                return val;
        }

        /**
         * Get a 3byte unsigned quantity.
         *
         * @return The value read.
         * @throws ReadFailedException When the file cannot be read.
         */
        @Override
        public int get3u() throws ReadFailedException {
                byte b1 = bytes[offset++];
                byte b2 = bytes[offset++];
                byte b3 = bytes[offset++];
                return ((b3 & 0xff) << 16) + ((b2 & 0xff) << 8) + (b1 & 0xff);
        }

        /**
         * Read in a 4 byte value.
         *
         * @return A 4 byte integer.
         */
        @Override
        public int get4() throws ReadFailedException {
                throw new UnsupportedOperationException();
        }

        /**
         * Read a variable sized integer.  The size is given.
         *
         * @param n The size of the integer to read. Must be 1 to 4.
         * @return The integer which will not be sign extended if it is less
         * than 4 bytes long.
         */
        @Override
        public int getNu(int n) throws ReadFailedException {
                throw new UnsupportedOperationException();
        }

        /**
         * Read in an arbitrary length sequence of bytes.
         *
         * @param len The number of bytes to read.
         */
        @Override
        public byte[] get(int len) throws ReadFailedException {
                byte[] res = new byte[len];
                System.arraycopy(bytes, offset, res, 0, len);
                offset += len;
                return res;
        }

        /**
         * Read a zero terminated string from the file.
         *
         * @return A string
         * @throws ReadFailedException For failures.
         */
        @Override
        public byte[] getZString() throws ReadFailedException {
                throw new UnsupportedOperationException();
        }

        /**
         * Read in a string of digits in the compressed base 11 format that is used
         * for phone numbers in the POI section.
         *
         * @param firstChar
         * @param delimiter This will replace all digit 11 characters.  Usually a
         * '-' to separate numbers in a telephone.  No doubt there is a different
         * standard in each country.
         * @return A phone number possibly containing the delimiter character.
         */
        @Override
        public String getBase11str(byte firstChar, char delimiter) {
                throw new UnsupportedOperationException();
        }

        /**
         * Closes this stream and releases any system resources associated
         * with it. If the stream is already closed then invoking this
         * method has no effect.
         *
         * @throws IOException if an I/O error occurs
         */
        @Override
        public void close() throws IOException {
                // Nothing to do.
        }
}