// **********************************************************************// // <copyright>// //  BBN Technologies//  10 Moulton Street//  Cambridge, MA 02138//  (617) 873-8000// //  Copyright (C) BBNT Solutions LLC. All rights reserved.// // </copyright>// **********************************************************************// // $Source: /cvs/distapps/openmap/src/openmap/com/bbn/openmap/layer/vpf/DcwCrossTileID.java,v $// $RCSfile: DcwCrossTileID.java,v $// $Revision: 1.2.2.2 $// $Date: 2005/08/09 21:17:52 $// $Author: dietrick $// // **********************************************************************package com.bbn.openmap.layer.vpf;import java.io.EOFException;import java.io.IOException;import com.bbn.openmap.MoreMath;import com.bbn.openmap.io.FormatException;import com.bbn.openmap.io.BinaryFile;/** * Encapsulate the VPF Cross-Tile identifier primitive datatype. The * cross-tile identifier relates map features that cross multiple * tiles. <br> * Note: Mil-Std-2407 cross tile ids have a fourth, unused field. This * class will read that field, but does not use it. */public class DcwCrossTileID {    /** the 1-byte length specifier for the rest of the values... */    //private int funkyDcwKeyValue = -1;    /** the key for this tile */    final public int currentTileKey;    /** the id for the connected tile */    final public int nextTileID;    /** the key in the adjoining tile */    final public int nextTileKey;    /** unused value in VPF... */    //private int unusedDcwKey = -1;    /**     * Construct a DcwCrossTileID     *      * @param currentTileKey primitive ID in current tile     * @param nextTileID tile ID     * @param nextTileKey primitive ID in nextTileID     */    public DcwCrossTileID(int currentTileKey, int nextTileID, int nextTileKey) {        this.currentTileKey = currentTileKey;        this.nextTileID = nextTileID;        this.nextTileKey = nextTileKey;    }    /**     * Construct a DcwCrossTileID from the specified input stream.     *      * @param in the filestream to construct from     * @exception FormatException some error was detected while     *            reading the info for the column.     * @exception EOFException EOF was encountered before reading any     *            data     */    public DcwCrossTileID(BinaryFile in) throws FormatException, EOFException {        int format;        try {            format = in.read();        } catch (IOException ioe) {            throw new FormatException(ioe.getMessage());        }        if (format == -1) {            throw new EOFException();        }        try {            currentTileKey = readIntegerByKey(in, format >> 6);            nextTileID = readIntegerByKey(in, format >> 4);            nextTileKey = readIntegerByKey(in, format >> 2);            /*int unusedDcwKey = */readIntegerByKey(in, format);        } catch (EOFException e) {            throw new FormatException("DcwCrossTileID: unexpected EOD "                    + e.getMessage());        }    }    /**     * Reads an integer from the input stream     *      * @param in the stream to read from     * @param key specifies the number of bytes to read (based on     *        bottom 2 bits)     * @return the integer read. (-1 for a zero-length field)     * @exception FormatException internal consistency failure     * @exception EOFException hit end-of-file while reading data     */    private int readIntegerByKey(BinaryFile in, int key)            throws FormatException, EOFException {        switch (key & 0x3) {        case 0:            return -1;        case 1: {            int byteval;            try {                byteval = in.read();            } catch (IOException ioe) {                throw new FormatException(ioe.getMessage());            }            if (byteval == -1) {                throw new EOFException();            }            return byteval;        }        case 2:            return MoreMath.signedToInt(in.readShort());        case 3:            return in.readInteger();        }        throw new FormatException("This can't happen");    }    /**     * produce a nice printed version of all our contained information     *      * @return a nice little string     */    public String toString() {        StringBuffer output = new StringBuffer();        output.append(currentTileKey).append("/");        if ((nextTileID != -1) && (nextTileKey != -1)) {            output.append(nextTileID).append(",");            output.append(nextTileKey);        }        return output.toString();    }}