001    /*
002     *    GeoAPI - Java interfaces for OGC/ISO standards
003     *    http://www.geoapi.org
004     *
005     *    Copyright (C) 2008-2012 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.style;
033    
034    import org.opengis.annotation.Extension;
035    import org.opengis.annotation.XmlElement;
036    import org.opengis.filter.expression.Expression;
037    
038    
039    /**
040     * The Displacement gives the X and Y displacements from the original geometry. This
041     * element may be used to avoid over-plotting of multiple PolygonSymbolizers for one
042     * geometry or supplying "shadows" of polygon gemeotries. The displacements are in units
043     * of pixels above and to the right of the point. The default displacement is X=0, Y=0.
044     *
045     * @version <A HREF="http://www.opengeospatial.org/standards/symbol">Symbology Encoding Implementation Specification 1.1.0</A>
046     * @author Open Geospatial Consortium
047     * @author Johann Sorel (Geomatys)
048     * @author Ian Turton, CCG
049     * @since GeoAPI 2.2
050     */
051    @XmlElement("Displacement")
052    public interface Displacement {
053    
054        /**
055         * Returns an expression that computes a pixel offset from the geometry
056         * point.  This offset point is where the text's anchor point gets
057         * located. If this expression is null, the default offset of zero is
058         * used.
059         *
060         * @return Expression
061         */
062        @XmlElement("DisplacementX")
063        Expression getDisplacementX();
064    
065        /**
066         * Returns an expression that computes a pixel offset from the geometry
067         * point.  This offset point is where the text's anchor point gets
068         * located. If this expression is null, the default offset of zero is
069         * used.
070         *
071         * @return Expression
072         */
073        @XmlElement("DisplacementY")
074        Expression getDisplacementY();
075    
076        /**
077         * calls the visit method of a StyleVisitor
078         *
079         * @param visitor the style visitor
080         */
081        @Extension
082        Object accept(StyleVisitor visitor, Object extraData);
083        
084    }
085