Maps Features

This section describes the main changes that have been made to Views Maps since version 4.

See also the Views Maps Classes code changes.

Load-On-Demand Framework

The following features are added:

  • A new class has been added to simplify the creation of tile loaders: the IlvMapTileLoader class. This class includes all standard rendering features and tile loading for all tile loaders.

  • IlvLookAheadFeatureIterator: Defines the interface for IlvMapFeatureIterator that has the ability to fetch the ID of the next feature before reading it, allowing you to skip the next feature if it is not needed.

  • Load-On-Demand for Shapefiles: Support for load-on-demand on ESRI Shapefiles has been added. To load Shapefiles on demand, a new type of file, with the .idx extension, has been introduced. These files contain the spatial indexes associated with Shapefiles.

The following classes have been added to support the load-on-demand feature:

IlvShapeFileIndex: To read the newly introduced ShapeFile index files (.shx extension)

IlvShapeSpatialIndex: To read the newly introduced spatial index files (.idx extension).

IlvShapeFileTileLoader: The tile loader for Shapefiles, to create load-on-demand layers when used in conjunction with IlvTiledLayer.

IlvShapeFileLayer: A tiled Shapefile layer that can be saved in an .ilv file.

The IlvShapeFileTiler class has been added to generate the spatial index files.

New Supported Formats

Support for loading single GeoTIFF files or tiled GeoTIFF files has been added.

The following classes have been added to support the GeoTIFF format:

  • IlvGeoTIFFReader: Reader for GeoTIFF files.

  • IlvGeoTIFFTileLoader: Tile loader for loading tiled GeoTIFF files.

  • IlvGeoTIFFLayer: A tiled GeoTIFF layer that can be saved in an .ilv file.

  • IlvGeoTIFFTiler: A class to produce tiled GeoTIFF file.

The ability to read image files has been added. The image formats supported are those supported by Views.

  • IlvImageReader: A class to read single image file.

  • IlvImageTileLoader: A class to read a set of images, each image representing a tile in a tiled data set.

  • IlvImageLayer: A tiled image layer that can be saved in an .ilv file.

File Name Resolution

A file name resolver mechanism has been added. This mechanism is used by the tile loaders to resolve pathnames.

The following classes support the file name resolver mechanism:

  • IlvMapDataPathManager: A class to manage path resolvers.

  • IlvDefaultDataPathResolver: A default implementation of an IlvMapDataPathResolver which looks for files in a directory.

  • IlvMapDataPathResolver: The abstract base class for all path resolvers.

Oracle Spatial

  • IlvObjectSDOWriter::setCheckingStringAttributes enables/disables the checking of String attributes.

  • IlvDefaultObjectSDOTileLoader::setRequestParameters sets some parameters in order to tune the request that is used by an IlvTile.

  • IlvObjectSDOUtil::GetLayerExtent computes the extent (the global bounding box of all geometries) of an SDO layer.

Samples

  • A new sample to show how to read and tile ShapeFile files has been added.

  • A new sample to show how to read and tile GeoTIFF files has been added.

  • A new sample to show how to read mutiresolution tiled data set (Shapefile and image) has been added.

  • The shape sample can now tile a Shapefile for load-on-demand.

MapBuilder

The following new features are added:

  • The MapBuilder is now able to read multiresolution data found in the data CD.

  • An Overview has been added.

  • The new legend enables the dragging/dropping of layers to change their order of appearance.

  • The new menu active on the legend allows you to dynamically change the rendering palette of each layer.

  • It now supports GeoTIFF and Shapefile load-on-demand.