Application: gvSIG desktop

package org.gvsig.fmap.dal.feature.impl;

import java.util.Arrays;

import org.gvsig.fmap.dal.DataTypes;

import org.gvsig.fmap.dal.exception.DataException;

import org.gvsig.fmap.dal.feature.AbstractFeatureStoreTransform;

import org.gvsig.fmap.dal.feature.EditableFeature;

import org.gvsig.fmap.dal.feature.EditableFeatureType;

import org.gvsig.fmap.dal.feature.Feature;

import org.gvsig.fmap.dal.feature.FeatureStore;

import org.gvsig.fmap.dal.feature.FeatureType;

import org.gvsig.fmap.geom.Geometry;

import org.gvsig.fmap.geom.GeometryFactory;

import org.gvsig.fmap.geom.GeometryManager;

import org.gvsig.tools.persistence.PersistenceException;

import org.gvsig.tools.persistence.PersistentState;

/**

 * 

 * This transform adds a new attribute of type Geometry to the original store's

 * default FeatureType. When applying the transform to a single feature this new

 * attribute is assigned the value of a point whose coordinates proceed from two

 * numeric attributes from the store, called xname, yname.

 * 

 */

class MyTransform extends AbstractFeatureStoreTransform {

        private String geomName;

        private String xname;

        private String yname;

        /**

         * Empty default constructor

         */

        public MyTransform() {

        }

        /**

         * Initializes the transform by assigning the source store and the names of

         * the necessary attributes.

         * 

         * @param store

         *            source store.

         * 

         * @param geomName

         *            name of the geometry attribute in the default feature type

         *            from the source store.

         * 

         * @param xname

         *            name of the attribute containing the X coordinates

         * 

         * @param yname

         *            name of the attribute containing the Y coordinates

         * 

         * @throws DataException

         */

        public void initialize(FeatureStore store, String geomName, String xname, String yname) throws DataException {

                // Initialize some data

                this.setFeatureStore(store);

                this.geomName = geomName;

                this.xname = xname;

                this.yname = yname;

                // obtain the feature type, add the new attribute and keep a reference to the resulting feature type

                EditableFeatureType type = store.getDefaultFeatureType().getEditable();

                type.add(geomName, DataTypes.GEOMETRY);

                FeatureType[] types = new FeatureType[] { type.getNotEditableCopy() };

                setFeatureTypes(Arrays.asList(types), types[0]);

        }

        /**

         * Applies this transform to a target editable feature, using data from the

         * source feature.

         */

        public void applyTransform(Feature source, EditableFeature target)

                        throws DataException {

                // copy source feature data over target feature

                target.copyFrom(source);

                // calculate and assign new attribute's value

                GeometryFactory geomFactory = GeometryManager.getInstance().getGeometryFactory();

                Geometry geom = geomFactory.createPoint2D(

                        source.getDouble(xname),

                        source.getDouble(yname)

                );

                target.setGeometry(this.geomName, geom);

        }

        public void loadState(PersistentState state) throws PersistenceException {

                state.set("geomName", this.geomName);

                state.set("xname", this.xname);

                state.set("yname", this.yname);

        }

        public void setState(PersistentState state) throws PersistenceException {

        }

}