/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2011, Open Source Geospatial Foundation (OSGeo)
* (C) 2008, Open Geospatial Consortium Inc.
*
* All Rights Reserved. http://www.opengis.org/legal/
*/
package org.opengis.style;
import org.opengis.annotation.Extension;
import org.opengis.annotation.XmlElement;
import org.opengis.filter.expression.Expression;
/**
* The Displacement gives the X and Y displacements from the original geometry. This
* element may be used to avoid over-plotting of multiple PolygonSymbolizers for one
* geometry or supplying "shadows" of polygon gemeotries. The displacements are in units
* of pixels above and to the right of the point. The default displacement is X=0, Y=0.
*
*
* @source $URL: http://svn.osgeo.org/geotools/branches/2.7.x/modules/library/opengis/src/main/java/org/opengis/style/Displacement.java $
* @version <A HREF="http://www.opengeospatial.org/standards/symbol">Symbology Encoding Implementation Specification 1.1.0</A>
* @author Open Geospatial Consortium
* @author Johann Sorel (Geomatys)
* @author Ian Turton, CCG
* @since GeoAPI 2.2
*/
@XmlElement("Displacement")
public interface Displacement {
/**
* Returns an expression that computes a pixel offset from the geometry
* point. This offset point is where the text's anchor point gets
* located. If this expression is null, the default offset of zero is
* used.
*
* @return Expression
*/
@XmlElement("DisplacementX")
Expression getDisplacementX();
/**
* Returns an expression that computes a pixel offset from the geometry
* point. This offset point is where the text's anchor point gets
* located. If this expression is null, the default offset of zero is
* used.
*
* @return Expression
*/
@XmlElement("DisplacementY")
Expression getDisplacementY();
/**
* calls the visit method of a StyleVisitor
*
* @param visitor the style visitor
*/
@Extension
Object accept(StyleVisitor visitor, Object extraData);
}