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.dal.feature.exception.CreateGeometryException;

import org.gvsig.fmap.geom.GeometryLocator;

import org.gvsig.fmap.geom.GeometryManager;

import org.gvsig.fmap.geom.Geometry.SUBTYPES;

import org.gvsig.fmap.geom.Geometry.TYPES;

import org.gvsig.fmap.geom.primitive.Point;

import org.gvsig.tools.persistence.PersistentState;

import org.gvsig.tools.persistence.exception.PersistenceException;

/**

 *

 * 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 FeatureType originalType;

        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;

                this.originalType = store.getDefaultFeatureType();

                // 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

                GeometryManager geomManager = GeometryLocator.getGeometryManager();

                Point point;

                try {

                        point = (Point)geomManager.create(TYPES.POINT, SUBTYPES.GEOM2D);

                        point.setX(source.getDouble(xname));

                        point.setY(source.getDouble(yname));

                        target.setGeometry(this.geomName, point);

                } catch (org.gvsig.fmap.geom.exception.CreateGeometryException e) {

                throw new CreateGeometryException(TYPES.POINT, SUBTYPES.GEOM2D, e);

                }

        }

        public void saveToState(PersistentState state) throws PersistenceException {

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

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

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

        }

        public void loadFromState(PersistentState state) throws PersistenceException {

        }

        /*

         * (non-Javadoc)

         *

         * @see

         * org.gvsig.fmap.dal.feature.FeatureStoreTransform#getSourceFeatureTypeFrom

         * (org.gvsig.fmap.dal.feature.FeatureType)

         */

        public FeatureType getSourceFeatureTypeFrom(FeatureType targetFeatureType) {

                return originalType;

        }

        public boolean isTransformsOriginalValues() {

                return false;

        }

}