org.opengis.geometry.primitive.Ring Maven / Gradle / Ivy

/*
 *    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 static org.opengis.annotation.Obligation.*;
import static org.opengis.annotation.Specification.*;

import org.opengis.annotation.UML;
import org.opengis.geometry.complex.CompositeCurve;

/**
 * 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.
 *
 * 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.
 *
 * @version ISO 19107
 * @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();
}