/**
   * @param placeNameServiceSet the set of PlaceNameService objects that PlaceNameLayer will render.
   * @throws IllegalArgumentException if {@link
   *     gov.nasa.worldwind.layers.placename.PlaceNameServiceSet} is null
   */
  public PlaceNameLayer(PlaceNameServiceSet placeNameServiceSet) {
    if (placeNameServiceSet == null) {
      String message = Logging.getMessage("nullValue.PlaceNameServiceSetIsNull");
      Logging.logger().fine(message);
      throw new IllegalArgumentException(message);
    }

    //
    this.placeNameServiceSet = placeNameServiceSet.deepCopy();
    for (int i = 0; i < this.placeNameServiceSet.getServiceCount(); i++) {
      // todo do this for long as well and pick min
      int calc1 =
          (int)
              (PlaceNameService.TILING_SECTOR.getDeltaLatDegrees()
                  / this.placeNameServiceSet
                      .getService(i)
                      .getTileDelta()
                      .getLatitude()
                      .getDegrees());
      int numLevels = (int) Math.log(calc1);
      navTiles.add(
          new NavigationTile(
              this.placeNameServiceSet.getService(i),
              PlaceNameService.TILING_SECTOR,
              numLevels,
              "top"));
    }

    if (!WorldWind.getMemoryCacheSet().containsCache(Tile.class.getName())) {
      long size = Configuration.getLongValue(AVKey.PLACENAME_LAYER_CACHE_SIZE, 2000000L);
      MemoryCache cache = new BasicMemoryCache((long) (0.85 * size), size);
      cache.setName("Placename Tiles");
      WorldWind.getMemoryCacheSet().addCache(Tile.class.getName(), cache);
    }
  }
 protected void buildSubNavTiles() {
   if (level > 0) {
     // split sector, create a navTile for each quad
     Sector[] subSectors = this.navSector.subdivide();
     for (int j = 0; j < subSectors.length; j++) {
       subNavTiles.add(
           new NavigationTile(placeNameService, subSectors[j], level - 1, this.id + "." + j));
     }
   }
 }
 public List<Tile> getTiles() {
   if (tileKeys.isEmpty()) {
     Tile[] tiles = buildTiles(this.placeNameService, this);
     // load tileKeys
     for (Tile t : tiles) {
       tileKeys.add(t.getFileCachePath());
       WorldWind.getMemoryCache(Tile.class.getName()).add(t.getFileCachePath(), t);
     }
     return Arrays.asList(tiles);
   } else {
     List<Tile> dataTiles = new ArrayList<Tile>();
     for (String s : tileKeys) {
       Tile t = (Tile) WorldWind.getMemoryCache(Tile.class.getName()).getObject(s);
       if (t != null) {
         dataTiles.add(t);
       }
     }
     return dataTiles;
   }
 }