/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2011, Open Source Geospatial Foundation (OSGeo)
* (C) 2003-2005, Open Geospatial Consortium Inc.
*
* All Rights Reserved. http://www.opengis.org/legal/
*/
package org.opengis.geometry.primitive;
import org.opengis.geometry.complex.CompositeCurve;
import org.opengis.annotation.UML;
import static org.opengis.annotation.Obligation.*;
import static org.opengis.annotation.Specification.*;
/**
* Represent a single connected component of a {@linkplain SurfaceBoundary surface boundary}.
* It consists of a number of references to {@linkplain OrientableCurve orientable curves}
* connected in a cycle (an object whose boundary is empty). A {@code Ring} is structurally
* similar to a {@linkplain CompositeCurve composite curve} in that the end point of each
* {@linkplain OrientableCurve orientable curve} in the sequence is the start point of the next
* {@linkplain OrientableCurve orientable curve} in the sequence. Since the sequence is circular,
* there is no exception to this rule. Each ring, like all boundaries is a cycle and each ring is
* simple.
* <p>
* Even though each {@code Ring} is simple, the boundary need not be simple. The easiest
* case of this is where one of the interior rings of a surface is tangent to its exterior ring.
* Implementations may enforce stronger restrictions on the interaction of boundary elements.
*
*
* @source $URL: http://svn.osgeo.org/geotools/trunk/modules/library/opengis/src/main/java/org/opengis/geometry/primitive/Ring.java $
* @version <A HREF="http://www.opengeospatial.org/standards/as">ISO 19107</A>
* @author Martin Desruisseaux (IRD)
* @since GeoAPI 1.0
*
* @see SurfaceBoundary
* @see Shell
*/
@UML(identifier="GM_Ring", specification=ISO_19107)
public interface Ring extends CompositeCurve {
/**
* Always returns {@code true} since ring objects are simples.
*
* @return Always {@code true}.
*/
@UML(identifier="isSimple", obligation=MANDATORY, specification=ISO_19107)
boolean isSimple();
}