Application: gvSIG desktop

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2013 gvSIG Association.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 3

 * of the License, or (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.fmap.geom.operation;

import org.gvsig.fmap.geom.Geometry;

import org.gvsig.fmap.geom.GeometryLocator;

/**

 * Every geometry operation that is registered dynamically must extend this class.<br>

 *

 * The following example shows how to implement and register a custom operation:

 *  

 * <pre>

 * public class MyOperation extends GeometryOperation {

 * 

 *   // Check GeometryManager for alternative methods to register an operation  

 *   public static final int CODE = 

 *     GeometryManager.getInstance()

 *        .registerGeometryOperation("MyOperation", new MyOperation(), geomType);

 *   

 *   public Object invoke(Geometry geom, GeometryOperationContext ctx) throws GeometryOperationException {

 *        // Operation logic goes here

 *   }     

 *   

 *   public int getOperationIndex() {

 *      return CODE;

 *   }

 *   

 * }

 * </pre>

 *

 * @author jiyarza

 *

 */

public abstract class GeometryOperation {

        // Constants for well-known operations to avoid dependency between geometry model and

        // operations.

        public static final String OPERATION_INTERSECTS_NAME = "intersects";

        public static final String OPERATION_CONTAINS_NAME = "contains";

        public static int OPERATION_INTERSECTS_CODE = Integer.MIN_VALUE;

        public static int OPERATION_CONTAINS_CODE = Integer.MIN_VALUE;

        /**

         * Invokes this operation given the geometry and context 

         * @param geom Geometry to which apply this operation

         * @param ctx Parameter container

         * @return Place-holder object that may contain any specific return value. 

         * @throws GeometryOperationException The implementation is responsible to throw this exception when needed.

         */

        public abstract Object invoke(Geometry geom, GeometryOperationContext ctx) throws GeometryOperationException;

        /**

         * Returns the constant value that identifies this operation and that was obtained upon registering it. 

         * @return operation unique index 

         */

        public abstract int getOperationIndex();

}