Application: gvSIG desktop » gvSIG projections

import java.util.List;

import java.util.Set;

import org.gvsig.proj.catalogue.cs.CoordinateSystemAxis;

import org.gvsig.proj.catalogue.datum.Datum;

 * Definition of a Coordinate Reference System (CRS).

 * A CRS defines how a set of coordinates relate to real positions (on earth, on other

 * planet or in the space). A CRS defines the number of coordinate axis, its name, order and

 * direction, its units, the mathematical model used to define the geometric figure (ellipsoid)

 * to approximate the shape of the earth, the relationship of this mathematical model with the

 * earth (datum), among other concepts and parameters. Some CRSs include a projection, which

 * defines a mathematical model to approximate the surface of an area of the earth using a

 * planar surface.

 * 

 * Note that a set of coordinates is meaningless if their CRS is not defined, as these

 * values can refer to different locations on the Earth depending on the CRS being used.

 * 

 * @author  Cesar Martinez Izquierdo

public interface CRSDefinition {

     * A common name for this coordinate reference system

     * 

     * @return the name, or {@code null} if none.

     */

	String getName();

    /**

     * Gets a code that references an unambiguous definition of the coordinate reference

     * system for some authority. Examples: "EPSG:4326", "EPSG:25830".

     * 

     * @return the identifier which was used to instantiate the object, or the

     * identifier that more closely matches the information used to instantiate

     * the object (e.g. if derived from an WKT definition)

     */

    String getIdentifier();

    /**

     * Gets the list of identifiers which describe this coordinate reference system

     * definition.

     *

     * @return the list of object identifiers, or an empty collection if there is none.

     */

    Set<String> getIdentifiers();

    /**

     * FIXME: GeoAPI

    /**

     * Textual description of the coordinate reference system, including remarks

     * and its scope. 

     *

     * @return the description, or {@code null} if none.

     */

    String getDescription();

    /**

     * Some CRSs include a projection, which defines a mathematical model to approximate

     * the surface of an area of the earth using a planar surface. CRS including a

     * projection are called projected CRSs

     * 

     * @return true if the CRS is projected, false otherwise

     */

    boolean isProjected();

    /**

     * Gets the type of coordinate reference system

     * 

     * @return

     */

    CRSType getType();

    /**

     * FIXME: GeoAPI

     * Returns a <cite>Well-Known Text</cite> (WKT) for this object.

     * Well-Known Texts (WKT) may come in two formats:

     *

     * <ul>

     *   <li>The current standard, WKT 2, is defined by ISO 19162.</li>

     *   <li>The legacy format, WKT 1, was defined by {@linkplain org.opengis.annotation.Specification#OGC_01009 OGC 01-009}

     *       and is shown using Extended Backus Naur Form (EBNF) <a href="doc-files/WKT.html">here</a>.</li>

     * </ul>

     *

     * Implementations are encouraged to format according the most recent standard.

     * This operation may fail if unsupported or if this instance contains elements that do not have

     * WKT representation.

     *

     * @return the Well-Known Text (WKT) for this object.

     * @throws UnsupportedOperationException if this object can not be formatted as WKT.

     *

     * @departure extension

     *   This method is not part of the OGC specification. It has been added in order to provide

     *   the converse of the <code>CRSFactory.createFromWKT(String)</code> method, which is

     *   defined in OGC 01-009.

     *

     * @see org.opengis.referencing.crs.CRSFactory#createFromWKT(String)

     */

	String toWKT() throws UnsupportedOperationException;

	/**

	* FIXME: GeoAPI & review definition

    * The ordered list of coordinate reference systems.

    *

    * @return the ordered list of coordinate reference systems.

    *

    * @departure generalization

    *   ISO 19111 said <cite>"nesting of compound CRSs shall not be permitted; the individual single systems

    *   shall be aggregated together"</cite>. However this approach causes data lost: it is difficult to add

    *   a temporal CRS to an existing three-dimensional compound CRS without loosing the name and identifiers

    *   of the 3D CRS, unless nesting is permitted. It is programmatically easier to convert nested CRSs to a

    *   flat list of single CRSs when needed than to reconstruct the 3D CRS from the single components.

    *   Consequently GeoAPI has been keep conformant with the legacy OGC 01-009 specification in this aspect,

    *   which were allowing nested compound CRS.

    *

    * @since 2.3

    */

	List<CRSDefinition> getComponents();

	/**

	 * Gets the number of axis of the associated CoordinateSystem

	 * 

	 * @return

	 */

	int getAxisCount();

	/**

	 * Returns the axis for the associated coordinate system at the specified dimension,

	 * as officially defined by the authority. 

	 * 

	 * @param dimension

	 * @return

	 * @throws IndexOutOfBoundsException

	 */

	CoordinateSystemAxis getAxis(int dimension) throws IndexOutOfBoundsException;

	/**

	 * Returns the axis for the associated coordinate system at the specified

	 * dimension as internally used by gvSIG, which will sometimes differ from

	 * the order officially defined by the authority.

	 * 

	 * The internal order is used for convenience and performance. gvSIG geometries

	 * and gvSIG coordinate transformations always expect coordinates to be provided

	 * using the internal order (xy axis order). However, some

	 * protocols or formats require the coordinates to be encoded using the

	 * official order. 

	 * 

	 * @param dimension

	 * @return

	 * @throws IndexOutOfBoundsException

	 */

	CoordinateSystemAxis getAxisInternal(int dimension) throws IndexOutOfBoundsException;

     * For derived CRSs, it returns the base coordinate reference system.

     * @return the base coordinate reference system or null if the CRS is not

     * derived

     * @see CRSType#isDerived()

     * @see CRSType#ProjectedCRSType

     * @see CRSType#OtherDerivedCRSType

     */

	CRSDefinition getBaseCRS();

    /**

     * For derived CRSs, it returns the conversion from the {@linkplain #getBaseCRS() base CRS}

     * to this CRS.

     * @return the conversion from the base CRS or null if the CRS is not derived

     *

     * @see CRSType#isDerived()

     * @see CRSType#ProjectedCRSType

     * @see CRSType#OtherDerivedCRSType

	TransformationDefinition getConversionFromBase();

    /**

     * Returns the datum associated directly or indirectly to this CRS.

     * In the case of a derived CRS, this method returns the

     * datum of the {@linkplain #getBaseCRS() base CRS}. In the case of

     * a compound CRS, it returns the datum associated to the horizontal component.

     *

     * @return the datum

     */

    Datum getDatum();