org.opengis.style.Halo Maven / Gradle / Ivy
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/*
* 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;
/**
* A Halo is a type of Fill that is applied to the backgrounds of font glyphs. The use of halos
* greatly improves the readability of text labels.
*
* @version Symbology Encoding
* Implementation Specification 1.1.0
* @author Open Geospatial Consortium
* @author Johann Sorel (Geomatys)
* @author Chris Dillard (SYS Technologies)
* @since GeoAPI 2.2
*/
@XmlElement("Halo")
public interface Halo {
/**
* Returns the object that indicates how the halo area around the text should be filled.
*
* The default halo fill is solid white (Color “#FFFFFF”). The glyph’s fill is plotted on top
* of the halo. The default font fill is solid black (Color “#000000”).
*
* @return Fill or null
*/
@XmlElement("Fill")
Fill getFill();
/**
* Returns the expression that will be evaluated to get the pixel radius of the halo around the
* text.
*
*
The Radius element gives the absolute size of a halo radius in pixels encoded as a
* floating-point number. The radius is taken from the outside edge of a font glyph to extend
* the area of coverage of the glyph (and the inside edge of “holes” in the glyphs). The halo of
* a text label is considered to be a single shape. The default radius is one pixel. Negative
* values are not allowed.
*
* @return Expression or null
*/
@XmlElement("Radius")
Expression getRadius();
/**
* calls the visit method of a StyleVisitor
*
* @param visitor the style visitor
*/
@Extension
Object accept(StyleVisitor visitor, Object extraData);
}