Subversion Repositories mkgmap

/*
 * Copyright (C) 2007 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 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.
 *
 *
 * Author: Steve Ratcliffe
 * Create date: Dec 15, 2007
 */
package uk.me.parabola.imgfmt.app;

import java.io.IOException;

/**
 * Represents an item size the position where those items start and the
 * total size of the section.
 */
public class Section {
        private char itemSize;
        private int size;
        private int position;
        private Section link;
        private int extraValue;

        public Section() {
        }

        public Section(char itemSize) {
                this.itemSize = itemSize;
        }

        public Section(Section link, char itemSize) {
                this.itemSize = itemSize;
                this.link = link;
        }

        public Section(Section link) {
                this.link = link;
        }

        public void inc() {
                size += itemSize;
        }

        public char getItemSize() {
                return itemSize;
        }

        public void setItemSize(char itemSize) {
                this.itemSize = itemSize;
        }

        public int getSize() {
                return size;
        }

        public void setSize(int size) {
                this.size = size;
        }

        /**
         * Get the start position of this section.  If this is linked to another
         * section, then we return the end address of that section.
         * @return The first offset for this section.
         */
        public int getPosition() {
                if (link != null)
                        return link.getEndPos();
                return position;
        }

        public void setPosition(int position) {
                this.position = position;
                // Setting a position breaks the link
                this.link = null;
        }

        /**
         * Get the position of the end of the section.
         * @return The offset of the end of the section relative to the beginning
         * of the application file.
         */
        public int getEndPos() {
                return getPosition() + size;
        }

        public String toString() {
                return "pos=" + getPosition() + ", size=" + size + ", itemSize=" + itemSize;
        }

        /**
         * Get the number of items in the section.  This should only be called
         * if the itemSize is set.
         * @return The number of items in the section, or zero if this is not
         * a fixed size item kind of section.
         */
        public int getNumItems() {
                if (itemSize == 0)
                        return 0;
               
                return size/ (int) itemSize;
        }

        protected int getExtraValue() {
                return extraValue;
        }

        public void setExtraValue(int extraValue) {
                this.extraValue = extraValue;
        }

        public void readSectionInfo(ImgFileReader reader, boolean withItemSize) {
                setPosition(reader.getInt());
                setSize(reader.getInt());
                if (withItemSize)
                        setItemSize(reader.getChar());
        }

        public SectionWriter makeSectionWriter(ImgFileWriter writer) {
                setPosition(writer.position());
                return new SectionWriter(writer, this);
        }

        public void writeSectionInfo(ImgFileWriter writer) {
                writeSectionInfo(writer, false);
        }

        public void writeSectionInfo(ImgFileWriter writer, boolean withItemSize) {
                writeSectionInfo(writer, withItemSize, false);
        }

        public void writeSectionInfo(ImgFileWriter writer, boolean withItemSize, boolean withExtraValue) {
                writer.putInt(getPosition());
                writer.putInt(getSize());
                if (withItemSize || getItemSize() > 0)
                        writer.putChar(getItemSize());
                if (withExtraValue)
                        writer.putInt(getExtraValue());
        }

        public static void close(ImgFileWriter writer) {
                assert writer instanceof SectionWriter;
                try {
                        writer.close();
                } catch (IOException e) {
                        // ignore as this is only for section writers.
                }
        }
}