coverageattributetable.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.

                // Part of the URL solution...
                // This makes sure that the tileid can be used
                // for the index. If the tile is not good, then
                // nullTile will be set. If it is good, it will be
                // replaced. This will end up putting nullTile at
                // index 1 if the tileid is 1.
                while (tileid > tileArrayList.size() - 1) {
                    tileArrayList.add(nullTile);
                }
                // End of solution addition part...

                if (!goodTile) {
                    // Commenting out line is part of the solution,
                    // the
                    // spot is already marked with a nullTile object.
                    //                  containedTiles[tileid] = null;
                    continue;
                }

                float westlon = ((Number) fbrv.get(fbrcols[0])).floatValue();
                float southlat = ((Number) fbrv.get(fbrcols[1])).floatValue();
                float eastlon = ((Number) fbrv.get(fbrcols[2])).floatValue();
                float northlat = ((Number) fbrv.get(fbrcols[3])).floatValue();

                //  Again, URL solution...
                //              containedTiles[tileid] = new
                // TileDirectory(tilename, tileid,
                //                                                         northlat, southlat,
                //                                                         eastlon, westlon);

                tileArrayList.set(tileid,
                        new TileDirectory(tilename, tileid, northlat, southlat, eastlon, westlon));

            }
            aft.close();
            fbr.close();

            // And this is the resolution of the solution, taking
            // the ArrayList and converting it to a TileDirectory
            // array.
            containedTiles = new TileDirectory[tileArrayList.size()];
            Iterator it = tileArrayList.iterator();
            int cnt = 0;
            while (it.hasNext()) {
                Object obj = it.next();
                if (obj == nullTile) {
                    containedTiles[cnt++] = null;
                } else {
                    containedTiles[cnt++] = (TileDirectory) obj;
                }
            }

        } catch (FormatException f) {
            //probably (hopefully?) untiled coverage...
            containedTiles = null;
        }
    }

    /**
     * Get the description of a coverage type
     * 
     * @param covname the name of the coverage type
     * @return the coverage description from the VPF database. A null
     *         return value indicates an unknown coverage type
     */
    public String getCoverageDescription(String covname) {
        CoverageEntry ce = (CoverageEntry) coverages.get(covname);
        return (ce == null) ? null : ce.getDescription();
    }

    /**
     * Get the topology level of a coverage.
     * 
     * @param covname the name of the coverage type
     * @return the topology level of the coverage (-1 if not a valid
     *         coverage)
     */
    public int getCoverageTopologyLevel(String covname) {
        CoverageEntry ce = (CoverageEntry) coverages.get(covname);
        return (ce == null) ? -1 : ce.getTopologyLevel();
    }

    /**
     * Get the CoverageTable for a particular coverage type
     * 
     * @param covname the name of the coverage type
     * @return the associated coverage table (possibly null)
     */
    public CoverageTable getCoverageTable(String covname) {
        CoverageEntry ce = (CoverageEntry) coverages.get(covname);
        if (ce != null) {
            if (ce.getCoverageTable() == null) {
                ce.setCoverageTable(new CoverageTable(dirpath, covname.intern(), this));
                if (Debug.debugging("vpf")) {
                    Debug.output("Created new CoverageTable for " + covname
                            + ": " + ce.description);
                }
            } else {
                if (Debug.debugging("vpf")) {
                    Debug.output("Using cached CoverageTable for " + covname
                            + ": " + ce.description);
                }
            }
            return ce.getCoverageTable();
        }
        return null;
    }
    
    public CoverageTable getCoverageTableForFeature(String featureName) {
        for (Iterator it = coverages.keySet().iterator(); it.hasNext();) {
            String key = (String)it.next();
            CoverageEntry ce = (CoverageEntry)coverages.get(key);
            Debug.output("CoverageTable: got " + ce + " for " + key);
            CoverageTable ct = ce.getCoverageTable();
            if (ct != null) {
                if (ct.getFeatureClassInfo(featureName) != null) {
                    return ct;
                }
            } else {
                Debug.output("no coverage table for " + ce);
            }
        }
        return null;
    }

    /**
     * get a list of tiles in the bounding region
     * 
     * @param n northern boundary
     * @param s southern boundary
     * @param e eating foundry
     * @param w wheat bread
     * @return a vector of TileDirectories
     */
    public List tilesInRegion(float n, float s, float e, float w) {
        if (containedTiles == null) {
            return null;
        }
        List retval = new ArrayList();
        int numTiles = containedTiles.length;
        for (int i = 0; i < numTiles; i++) {
            TileDirectory tile = containedTiles[i];
            if (tile != null && tile.inRegion(n, s, e, w)) {
                retval.add(tile);
            }
        }
        return retval;
    }

    /**
     * Get the TileDirectory with the given ID number.
     */
    public TileDirectory getTileWithID(int id) {
        try {
            return containedTiles[id];
        } catch (ArrayIndexOutOfBoundsException aioobe) {
            return null;
        }
    }

    /**
     * Know that the tile id are the integers used in the tileref.aft
     * file. May return null if the format of the id is bad, or if the
     * tile doesn't really exist (that really shouldn't happen).
     */
    public TileDirectory getTileWithID(String id) {
        try {
            return getTileWithID(Integer.parseInt(id));
        } catch (NumberFormatException nfe) {
            return null;
        }
    }

    /**
     * Find out if this library uses tiled data
     * 
     * @return true for tiled data
     */
    public boolean isTiledData() {
        return (containedTiles != null);

    }

    /**
     * Return the list of coverages this library has
     * 
     * @return the list of coverages (DCW would include "po", "dn";
     *         VMAP would have "bnd", "tran", etc.)
     */
    public String[] getCoverageNames() {
        return (String[]) coverages.keySet()
                .toArray(Constants.EMPTY_STRING_ARRAY);
    }

    /**
     * A utility class to hold information about one coverage type.
     * Only the associated coverage table may be modified after
     * construction.
     */
    public static class CoverageEntry {
        /** the VPF topology level of this coverage type */
        private final int tLevel;
        /** the VPF description string of this coverage type */
        private final String description;
        /** the CoverageTable for this coverage type */
        private CoverageTable covtable;

        /**
         * Create a coverage entry without a coverage table
         * 
         * @param topologyLevel the topology level for this
         *        coverageentry
         * @param desc the description for this entry
         */
        public CoverageEntry(int topologyLevel, String desc) {
            this(topologyLevel, desc, null);
        }

        /**
         * Create a coverage entry with an initial coverage table
         * 
         * @param topologyLevel the topology level for this
         *        coverageentry
         * @param desc the description for this entry
         * @param covtable the coveragetable for this entry
         */
        public CoverageEntry(int topologyLevel, String desc,
                CoverageTable covtable) {
            this.tLevel = topologyLevel;
            this.description = desc;
            this.covtable = covtable;
        }

        /**
         * Get the topology level for this entry
         */
        public int getTopologyLevel() {
            return tLevel;
        }

        /**
         * Get the description for this entry
         */
        public String getDescription() {
            return description;
        }

        /**
         * Get the associated coveragetable
         */
        public CoverageTable getCoverageTable() {
            return covtable;
        }

        /**
         * Set the associated coveragetable
         * 
         * @param covtable the new coveragetable
         */
        /* package */void setCoverageTable(CoverageTable covtable) {
            this.covtable = covtable;
        }
    }
}