featureclassinfo.java

openmap java写的开源数字地图程序. 用applet实现,可以像google map 那样放大缩小地图.

// **********************************************************************
// 
// <copyright>
// 
//  BBN Technologies
//  10 Moulton Street
//  Cambridge, MA 02138
//  [phone]
// 
//  Copyright (C) BBNT Solutions LLC. All rights reserved.
// 
// </copyright>
// **********************************************************************
// 
// $Source: /cvs/distapps/openmap/src/openmap/com/bbn/openmap/layer/vpf/FeatureClassInfo.java,v $
// $RCSfile: FeatureClassInfo.java,v $
// $Revision: 1.3.2.4 $
// $Date: 2005/08/11 21:03:13 $
// $Author: dietrick $
// 
// **********************************************************************

package com.bbn.openmap.layer.vpf;

import java.util.ArrayList;
import java.util.List;

import com.bbn.openmap.io.FormatException;
import com.bbn.openmap.util.Debug;

/**
 * This class wraps a feature type file (potext.tft, polbndl.lft, etc)
 * from VPF. It maintains sufficient information about the table it is
 * indexed from so that it can take a List of values, rather than a
 * single value. It also knows about its containing CoverageTable so
 * it can look up information in int.vdt and char.vdt.
 */
public class FeatureClassInfo extends DcwRecordFile implements
        TerminatingRunnable, com.bbn.openmap.io.Closable {

    /** the table to look up .vdt info from */
    final private CoverageTable ctable;
    /**
     * The name of our column from the primitive table (e.g.
     * potext.tft_id). This is the name of the column that will let
     * you know, in the primitive file (like edg), what type of
     * primitive (featurewise) is being reprensented on that row. This
     * field does not always exist! If it doesn't, all the features in
     * the file are rendered.
     */
    final private String columnname;

    /** the column number in the primitive table for columnname */
    private int mycolumn = -1;
    /** true means the object has run(), false otherwise */
    private boolean fullInit = false;

    /** things constructed with deferred initialization get queued here */
    // private static RunQueue tq = new RunQueue(true, Thread.MIN_PRIORITY, true);

    /** temporary list for use in getDescription() */
    final private List tmpVec = new ArrayList();

    // Feature Classes cross reference each other. For any feature
    // class name, you can have:
    //
    // 1) a DcwRecordFile (EdgeTable, NodeTable, AreaTable,
    // TextTable), with a certain column used as an ID, reference a
    // FeatureTable with a column that uses that ID.
    //
    // 2) a FeatureTable (.pft, .aft, .lft, .tft) using a column
    // holding an ID, referencing a DcwRecordFile with a column
    // holding that ID.
    //
    // The FeatureTable shows, for a particular feature type, the
    // individual primitive features for that particular feature type,
    // their FACC code, what tile that feature resides in, and the
    // feature ID number in that tile.
    //
    // The DcwRecordFile contains the actual data for the primitive,
    // and each DceRecordFile contains like feature primitives (edges,
    // areas, text, points). Each line in the DcwRecordFile contains
    // the ID number of the primitive,

    /**
     * Construct a FeatureClassInfo.
     * 
     * @param cthis the CoverageTable to use for vdt lookups
     * @param colname the column name from the primitive table
     * @param tablepath the directory of the feature table
     * @param ftname the name of the feature type
     * @exception FormatException some error was encountered
     */
    public FeatureClassInfo(CoverageTable cthis, String colname,
            String tablepath, String ftname) throws FormatException {
        super(tablepath + ftname, true); //defer initialization

        if (Debug.debugging("vpf.fci")) {
            Debug.output("FCI: set to peruse (" + filename
                    + ")\n\tcreated with colname (" + colname
                    + ")\n\ttablepath (" + tablepath + ")\n\tftname (" + ftname
                    + ")");
        }

        ctable = cthis;
        columnname = colname.toLowerCase().intern();
    }

    /** the name of the primitive file: edg, fac, end, cnd */
    protected String tileFileName;
    /** the name of the column with the primitive id */
    protected String tileFileColName;
    /** the type of feature this table represents */
    protected char featureType;

    /**
     * Construct a FeatureClassInfo that can be used for feature
     * search
     * 
     * @param cthis the CoverageTable to use for vdt lookups
     * @param colname the column name from the primitive table
     * @param tablepath the directory of the feature table
     * @param ftname the name of the feature type
     * @param tileDirFile the name of the primitive file
     * @param tileDirFileColName the name of the primitive id column
     * @exception FormatException some error was encountered
     */
    public FeatureClassInfo(CoverageTable cthis, String colname,
            String tablepath, String ftname, String tileDirFile,
            String tileDirFileColName) throws FormatException {

        super(tablepath + ftname, false); //don't defer
        // initialization
        fullInit = true;

        ctable = cthis;
        columnname = colname.toLowerCase().intern();

        tileFileName = tileDirFile;
        tileFileColName = tileDirFileColName;

        if ("fac".equals(tileFileName)) {
            featureType = CoverageTable.AREA_FEATURETYPE;
        } else if ("end".equals(tileFileName)) {
            featureType = CoverageTable.EPOINT_FEATURETYPE;
        } else if ("cnd".equals(tileFileName)) {
            featureType = CoverageTable.CPOINT_FEATURETYPE;
        } else if ("txt".equals(tileFileName)) {
            featureType = CoverageTable.TEXT_FEATURETYPE;
        } else if ("edg".equals(tileFileName)) {
            featureType = CoverageTable.EDGE_FEATURETYPE;
        } else {
            featureType = CoverageTable.SKIP_FEATURETYPE;
        }

        if (Debug.debugging("vpf.fci")) {
            Debug.output("FCI: set to peruse (" + filename
                    + ")\n\tcreated with column name (" + colname
                    + ")\n\ttile directory file (" + tileDirFile
                    + ")\n\ttile id column (" + tileDirFileColName + ")");
        }
    }

    /**
     * Returns a TilingAdapter suitable for retrieving primitive ids
     * from records in this feature table.
     * 
     * @return a tilingadapter or null
     */
    public TilingAdapter getTilingAdapter() {
        return getTilingAdapter(TILE_ID_COLUMN_NAME, tileFileColName);
    }

    /** the name of the column where tiling information lives */
    public final static String TILE_ID_COLUMN_NAME = "tile_id";

    /**
     * Returns the file name (no path info) of the thematic index for
     * the tile_id column.
     */
    public String getTileThematicFileName() {
        if (columnInfo != null) {
            int colId = getTileIdIndex();
            if (colId != -1) {
                return columnInfo[colId].getThematicIndexName();
            }
        }
        return null;
    }

    /** the thematic index for the tile_id column */
    protected DcwThematicIndex thematicIndex = null;

    /**
     * Causes the thematic index for the tile_id column to be
     * initilized.
     * 
     * @param path the path to the directory where the index lives
     * @return true if a thematic index is available, false if not
     */
    public synchronized boolean initThematicIndex(String path) {
        try {
            if (thematicIndex == null) {
                // See if we can use the thematic index to see which
                // tiles
                // have the features we want.
                String thematicIndexName = getTileThematicFileName();
                if (thematicIndexName != null) {
                    thematicIndex = new DcwThematicIndex(path
                            + thematicIndexName, byteorder);
                }
            }
        } catch (FormatException fe) {
            if (Debug.debugging("vpf.FormatException")) {
                Debug.output("FeatureClassInfo.initTI: " + fe.getClass() + " "
                        + fe.getMessage());
            }
            return false;
        }
        return (thematicIndex != null);
    }

    /**
     * Returns the thematic index for the tile_id column, if it has
     * been initialized.
     * 
     * @return null or a themaitc index for the column
     */
    public DcwThematicIndex getThematicIndex() {
        return thematicIndex;
    }

    /**
     * Returns the column position of the tile_id column.
     * 
     * @see DcwRecordFile#whatColumn(String)
     */
    public int getTileIdIndex() {
        return whatColumn(TILE_ID_COLUMN_NAME);
    }

    /**
     * Returns the column position of the f_code column.
     * 
     * @see DcwRecordFile#whatColumn(String)