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Standard interfaces implemented throughout the library.
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/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2011, Open Source Geospatial Foundation (OSGeo)
 *    (C) 2004-2007 Open Geospatial Consortium Inc.
 *
 *    All Rights Reserved. http://www.opengis.org/legal/
 */
package org.opengis.feature;

import org.opengis.feature.type.GeometryDescriptor;
import org.opengis.feature.type.GeometryType;
import org.opengis.geometry.BoundingBox;

/**
 * An attribute which has a geometric value.
 *
 * The type of the value of the attribute is an arbitrary object and is implementation dependent.
 * Implementations of this interface may wish to type narrow {@link Property#getValue()} to be
 * specific about the type geometry. For instance to return explicitly a JTS geometry.
 *
 * 
Past a regular attribute, GeometryAttribute provides a method for obtaining the bounds of the
 * underlying geometry, {@link #getBounds()}. The {@link #setBounds(BoundingBox)} method is used to
 * explicitly set the bounds which can be useful in situations where the data source stores the
 * bounds explicitly along with the geometry.
 *
 * @author Jody Garnett, Refractions Research
 * @author Justin Deoliveira, The Open Planning Project
 */
public interface GeometryAttribute extends Attribute {

    /** Override and type narrow to GeometryType. */
    GeometryType getType();

    /**
     * Override and type narrow to GeometryDescriptor.
     *
     * @return The geometry descriptor, may be null if this is a top-level value
     */
    GeometryDescriptor getDescriptor();

    /**
     * The bounds of the attribute.
     *
     * 
This value should be derived unless explicitly set via {@link #setBounds(BoundingBox)}.
     *
     * 
In the case that the underlying geometry is null, this method should return
     * an empty bounds as opposed to returning null.
     *
     * @return The bounds of the underlying geometry, possibly empty.
     */
    BoundingBox getBounds();

    /**
     * Sets the bounds of the geometry.
     *
     * 
This method should be used when the bounds is pre-computed and there is no need to derive
     * it from scratch. This is mostly only relevant to data sources which store the bounds along
     * with the geometry.
     *
     * Setting the bounds to null is allowed and will force the bounds to be derived
     * manually on the next call to {@link #getBounds()}.
     *
     * @param bounds The bounds of the attribute.
     */
    void setBounds(BoundingBox bounds);
}