CreateArcBehaviour.java

/* Spatial Operations & Editing Tools for uDig
 * 
 * Axios Engineering under a funding contract with: 
 *      Diputación Foral de Gipuzkoa, Ordenación Territorial 
 *
 *      http://b5m.gipuzkoa.net
 *      http://www.axios.es 
 *
 * (C) 2006, Diputación Foral de Gipuzkoa, Ordenación Territorial (DFG-OT). 
 * DFG-OT agrees to license under Lesser General Public License (LGPL).
 * 
 * You can redistribute it and/or modify it under the terms of the 
 * GNU Lesser General Public License as published by the Free Software 
 * Foundation; version 2.1 of the License.
 *
 * This library 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
 * Lesser General Public License for more details.
 */
package es.axios.udig.ui.editingtools.arc.internal;

import net.refractions.udig.project.ILayer;
import net.refractions.udig.project.command.UndoableMapCommand;
import net.refractions.udig.project.command.factory.EditCommandFactory;
import net.refractions.udig.project.internal.commands.edit.CreateFeatureCommand;
import net.refractions.udig.tools.edit.Behaviour;
import net.refractions.udig.tools.edit.EditState;
import net.refractions.udig.tools.edit.EditToolHandler;
import net.refractions.udig.tools.edit.support.PrimitiveShape;

import org.geotools.feature.simple.SimpleFeatureBuilder;
import org.opengis.feature.IllegalAttributeException;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.opengis.referencing.operation.OperationNotFoundException;
import org.opengis.referencing.operation.TransformException;

import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.Point;

import es.axios.geotools.util.GeoToolsUtils;
import es.axios.lib.geometry.util.GeometryUtil;
import es.axios.udig.ui.commons.mediator.AppGISMediator;
import es.axios.udig.ui.commons.util.DialogUtil;
import es.axios.udig.ui.commons.util.LayerUtil;

/**
 * Acceptance behaviour for the arc creation tool.
 * <p>
 * This behaviour uses an ArcBuilder to create an arc's approximation as a JTS
 * LineString and returns {@link CreateFeatureCommand} with the arc
 * approximation as default geometry.
 * </p>
 * <p>
 * The geometry is created in the current map's
 * {@link CoordinateReferenceSystem} and then projected back to the current
 * layer's CRS.
 * </p>
 * 
 * @author Aritz Davila (www.axios.es)
 * @author Mauricio Pazos (www.axios.es)
 * @since 1.1.0
 * @see ArcBuilder
 */
public class CreateArcBehaviour implements Behaviour {

	/**
	 * Valid if current shape is not null and has exactly three points.
	 */
	public boolean isValid(EditToolHandler handler) {
		PrimitiveShape currentShape = handler.getCurrentShape();
		if (currentShape == null) {
			return false;
		}
		int nCoords = currentShape.getNumCoords();
		return nCoords == 3;
	}

	public UndoableMapCommand getCommand(EditToolHandler handler) {
		final PrimitiveShape currentShape = handler.getCurrentShape();
		final ILayer editLayer = handler.getEditLayer();

		// need to use map coordinates in order to avoid
		// possible inconsistencies between what the user
		// drawn and the projected result
		GeometryFactory gf = new GeometryFactory();
		CoordinateReferenceSystem layerCrs = LayerUtil.getCrs(editLayer);
		CoordinateReferenceSystem mapCrs = editLayer.getMap().getViewportModel().getCRS();
		Point p1 = gf.createPoint(currentShape.getCoord(0));
		Point p2 = gf.createPoint(currentShape.getCoord(1));
		Point p3 = gf.createPoint(currentShape.getCoord(2));

		try {
			p1 = (Point) GeoToolsUtils.reproject(p1, layerCrs, mapCrs);
			p2 = (Point) GeoToolsUtils.reproject(p2, layerCrs, mapCrs);
			p3 = (Point) GeoToolsUtils.reproject(p3, layerCrs, mapCrs);
		} catch (OperationNotFoundException onfe) {
			throw new RuntimeException(onfe);
		} catch (TransformException te) {
			throw new RuntimeException(te);
		}

		ArcBuilder builder = new ArcBuilder();
		builder.setPoints(p1.getX(), p1.getY(), p2.getX(), p2.getY(), p3.getX(), p3.getY());

		// TODO: especificar la cantidad de segmentos por cuadrante
		// mediante una preferencia
		Geometry geom = builder.getGeometry(15);
		if (geom == null) {
			throw new RuntimeException("null geom");
		}

		// backproject resulting geom from map crs to layer's crs
		try {
			geom = GeoToolsUtils.reproject(geom, mapCrs, layerCrs);
		} catch (OperationNotFoundException onfe) {
			throw new RuntimeException(onfe);
		} catch (TransformException te) {
			throw new RuntimeException(te);
		}

		EditCommandFactory editCmdFac = AppGISMediator.getEditCommandFactory();

		ILayer layer = editLayer;
		SimpleFeatureType schema = layer.getSchema();
		SimpleFeature feature;
		try {
			feature = SimpleFeatureBuilder.build(schema, new Object[1], null);

			assert feature != null : "feature creation fail.";

			Class<? extends Geometry> type = (Class<? extends Geometry>) schema.getGeometryDescriptor().getType()
						.getBinding();
			geom = GeometryUtil.adapt(geom, type);
			feature.setDefaultGeometry(geom);
		} catch (IllegalAttributeException e) {
			throw new RuntimeException(e);
		}
		UndoableMapCommand command = editCmdFac.createAddFeatureCommand(feature, layer);

		handler.setCurrentShape(null);
		handler.setCurrentState(EditState.NONE);

		return command;
	}

	public void handleError(EditToolHandler handler, Throwable error, UndoableMapCommand command) {
		error.printStackTrace();
		DialogUtil.openError("Create arc failed to execute", error.getMessage());
	}
}