001    /*
002     *    GeoAPI - Java interfaces for OGC/ISO standards
003     *    http://www.geoapi.org
004     *
005     *    Copyright (C) 2004-2012 Open Geospatial Consortium, Inc.
006     *    All Rights Reserved. http://www.opengeospatial.org/ogc/legal
007     *
008     *    Permission to use, copy, and modify this software and its documentation, with
009     *    or without modification, for any purpose and without fee or royalty is hereby
010     *    granted, provided that you include the following on ALL copies of the software
011     *    and documentation or portions thereof, including modifications, that you make:
012     *
013     *    1. The full text of this NOTICE in a location viewable to users of the
014     *       redistributed or derivative work.
015     *    2. Notice of any changes or modifications to the OGC files, including the
016     *       date changes were made.
017     *
018     *    THIS SOFTWARE AND DOCUMENTATION IS PROVIDED "AS IS," AND COPYRIGHT HOLDERS MAKE
019     *    NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
020     *    TO, WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT
021     *    THE USE OF THE SOFTWARE OR DOCUMENTATION WILL NOT INFRINGE ANY THIRD PARTY
022     *    PATENTS, COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS.
023     *
024     *    COPYRIGHT HOLDERS WILL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL OR
025     *    CONSEQUENTIAL DAMAGES ARISING OUT OF ANY USE OF THE SOFTWARE OR DOCUMENTATION.
026     *
027     *    The name and trademarks of copyright holders may NOT be used in advertising or
028     *    publicity pertaining to the software without specific, written prior permission.
029     *    Title to copyright in this software and any associated documentation will at all
030     *    times remain with copyright holders.
031     */
032    package org.opengis.geometry.primitive;
033    
034    import org.opengis.geometry.complex.CompositeCurve;
035    import org.opengis.annotation.UML;
036    
037    import static org.opengis.annotation.Obligation.*;
038    import static org.opengis.annotation.Specification.*;
039    
040    
041    /**
042     * Represent a single connected component of a {@linkplain SurfaceBoundary surface boundary}.
043     * It consists of a number of references to {@linkplain OrientableCurve orientable curves}
044     * connected in a cycle (an object whose boundary is empty). A {@code Ring} is structurally
045     * similar to a {@linkplain CompositeCurve composite curve} in that the end point of each
046     * {@linkplain OrientableCurve orientable curve} in the sequence is the start point of the next
047     * {@linkplain OrientableCurve orientable curve} in the sequence. Since the sequence is circular,
048     * there is no exception to this rule. Each ring, like all boundaries is a cycle and each ring is
049     * simple.
050     * <p>
051     * Even though each {@code Ring} is simple, the boundary need not be simple. The easiest
052     * case of this is where one of the interior rings of a surface is tangent to its exterior ring.
053     * Implementations may enforce stronger restrictions on the interaction of boundary elements.
054     *
055     * @version <A HREF="http://www.opengeospatial.org/standards/as">ISO 19107</A>
056     * @author Martin Desruisseaux (IRD)
057     * @since GeoAPI 1.0
058     *
059     * @see SurfaceBoundary
060     * @see Shell
061     */
062    @UML(identifier="GM_Ring", specification=ISO_19107)
063    public interface Ring extends CompositeCurve {
064        /**
065         * Always returns {@code true} since ring objects are simples.
066         *
067         * @return Always {@code true}.
068         */
069        @UML(identifier="isSimple", obligation=MANDATORY, specification=ISO_19107)
070        boolean isSimple();
071    }