/*
 *    GeoTools - OpenSource mapping toolkit
 *    http://geotools.org
 *    (C) 2002-2006, GeoTools Project Managment Committee (PMC)
 *
 *    This library is free software; you can redistribute it and/or
 *    modify it under the terms of the GNU Lesser General Public
 *    License as published by the Free Software Foundation;
 *    version 2.1 of the License.
 *
 *    This library is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *    Lesser General Public License for more details.
 */

/*
 * Geotools - OpenSource mapping toolkit
 *            (C) 2002, Center for Computational Geography
 *
 *    This library is free software; you can redistribute it and/or
 *    modify it under the terms of the GNU Lesser General Public
 *    License as published by the Free Software Foundation;
 *    version 2.1 of the License.
 *
 *    This library is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *    Lesser General Public License for more details.
 *
 *    You should have received a copy of the GNU Lesser General Public
 *    License along with this library; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *
 * Contacts:
 *     UNITED KINGDOM: James Macgill.  j.macgill@geog.leeds.ac.uk
 */
package org.geotools.styling;

import org.opengis.filter.expression.Expression;


/**
 * The "LinePlacement" specifies where and how a text label should be rendered
 * relative to a line.
 *
 * <p>
 * The details of this object are taken from the <a
 * href="https://portal.opengeospatial.org/files/?artifact_id=1188"> OGC
 * Styled-Layer Descriptor Report (OGC 02-070) version 1.0.0.</a>:
 * <pre><code>
 * &lt;xsd:element name="LinePlacement"&gt;
 *   &lt;xsd:annotation&gt;
 *     &lt;xsd:documentation&gt;
 *       A "LinePlacement" specifies how a text label should be rendered
 *       relative to a linear geometry.
 *     &lt;/xsd:documentation&gt;
 *   &lt;/xsd:annotation&gt;
 *   &lt;xsd:complexType&gt;
 *     &lt;xsd:sequence&gt;
 *       &lt;xsd:element ref="sld:PerpendicularOffset" minOccurs="0"/&gt;
 *     &lt;/xsd:sequence&gt;
 *   &lt;/xsd:complexType&gt;
 * &lt;/xsd:element&gt;
 * </code></pre>
 * </p>
 *
 * <p>
 * $Id: LinePlacement.java 25459 2007-05-08 05:19:25Z jgarnett $
 * </p>
 *
 * @author Ian Turton, CCG
 * @source $URL: http://svn.geotools.org/geotools/tags/2.4.1/modules/library/api/src/main/java/org/geotools/styling/LinePlacement.java $
 */
public interface LinePlacement extends LabelPlacement {
    /**
     * Returns the expression that is used to compute how far from the lines
     * the text will be drawn.  The distance must evaluate to a non-negative
     * number.
     *
     * @return DOCUMENT ME!
     */
    Expression getPerpendicularOffset();

    /**
     * Sets the expression that is used to compute how far from the lines the
     * text will be drawn. See {@link #getPerpendicularOffset} for details.
     *
     * @param offset DOCUMENT ME!
     */
    void setPerpendicularOffset(Expression offset);
}
