/*
 *    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 "LinePlacement" specifies where and how a text label should be rendered
 * relative to a line.
 *
 *
 * @source $URL: http://svn.osgeo.org/geotools/trunk/modules/library/opengis/src/main/java/org/opengis/style/LinePlacement.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("LinePlacement")
public interface LinePlacement extends LabelPlacement {

    /**
     * The PerpendicularOffset element of a LinePlacement gives the perpendicular distance
     * away from a line to draw a label.
     *
     * The distance is in uoms and is positive to the left-hand side of the line string. Negative
     * numbers mean right. The default offset is 0.
     *
     * @return Expression
     */
    @XmlElement("PerpendicularOffset")
    Expression getPerpendicularOffset();

    /**
     * InitialGap specifies how far away the first graphic will be drawn relative to the start of
     * the rendering line
     *
     * @return Expression
     */
    @XmlElement("InitialGap")
    Expression getInitialGap();

    /**
     * Gap gives the distance between two graphics.
     *
     * @return Expression
     */
    @XmlElement("Gap")
    Expression getGap();

    /**
     * If IsRepeated is "true", the label will be repeatedly drawn
     * along the line with InitialGap and Gap defining the spaces at the
     * beginning and between labels.
     *
     * @return boolean
     */
    @XmlElement("IsRepeated")
    boolean isRepeated();

    /**
     * Labels can either be aligned to the line geometry if IsAligned is "true" (the default) or are
     * drawn horizontally.
     *
     * @return boolean
     */
    @XmlElement("IsAligned")
    boolean IsAligned();

    /**
     * GeneralizeLine allows the actual geometry, be it a
     * linestring or polygon to be generalized for label placement. This is e.g. useful for
     * labelling polygons inside their interior when there is need for the label to resemble the
     * shape of the polygon.
     *
     * @return boolean
     */
    @XmlElement("GeneralizeLine")
    boolean isGeneralizeLine();
    
    /**
     * calls the visit method of a StyleVisitor
     *
     * @param visitor the style visitor
     */
    @Extension
    Object accept(StyleVisitor visitor, Object extraData);

}