Module org.opengis.geoapi

Package org.opengis.geometry.coordinate

Interface Position

All Known Subinterfaces:

DirectPosition

@UML(identifier="GM_Position",
     specification=ISO_19107)
public interface Position

A type consisting of either a direct position or of a point from which a direct position shall be obtained. The use of this data type allows the identification of a position either directly as a coordinate (variant direct) or indirectly as a point (variant indirect).

Since:

1.0

Departure from OGC/ISO abstract specification:

Departure due to constraint of the Java language

ISO 19107 defines Position as a union of DirectPosition and Point but unions are not allowed in Java. GeoAPI defines Position as the base interface of both types so the two conditional accessor methods, getPoint() and getDirectPosition(), can be replaced by an instanceof check. However, the getDirectPosition() has been retained with different semantics, conceptually returning a DirectPosition at the same location. The conditionality has also been changed to mandatory since all three types conceptually have a well defined location.

Method Summary

Modifier and Type	Method	Description
DirectPosition	getDirectPosition()	Returns the direct position.

Method Details

getDirectPosition

@UML(identifier="direct",
     obligation=CONDITIONAL,
     specification=ISO_19107)
DirectPosition getDirectPosition()

Returns the direct position. This method shall never returns null, but may returns this if invoked on an object which is already a DirectPosition instance.

Returns:

The direct position (may be this).

Since:

2.2