/*
 * The Unified Mapping Platform (JUMP) is an extensible, interactive GUI 
 * for visualizing and manipulating spatial features with geometry and attributes.
 *
 * JUMP is Copyright (C) 2003 Vivid Solutions
 *
 * This program implements extensions to JUMP and is
 * Copyright (C) 2004 Integrated Systems Analysts, Inc.
 * 
 * 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 2
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 * 
 * For more information, contact:
 *
 * Integrated Systems Analysts, Inc.
 * 630C Anchors St., Suite 101
 * Fort Walton Beach, Florida
 * USA
 *
 * (850)862-7321
 */

package org.openjump.core.ui.plugin.edittoolbox.cursortools;

import java.awt.geom.NoninvertibleTransformException;
import java.util.ArrayList;

import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.Polygon;
import com.vividsolutions.jts.operation.valid.IsValidOp;
import com.vividsolutions.jump.workbench.ui.EditTransaction;

public abstract class ConstrainedPolygonTool extends ConstrainedMultiClickTool {
    public ConstrainedPolygonTool() 
    {
        drawClosed = true;
    }

    /**
     * Callers should check whether the polygon returned is valid.
     */
    protected Polygon getPolygon() throws NoninvertibleTransformException {
        ArrayList closedPoints = new ArrayList(getCoordinates());

        if (!closedPoints.get(0).equals(closedPoints.get(closedPoints.size() - 1))) {
            closedPoints.add(new Coordinate((Coordinate) closedPoints.get(0)));
        }

        return new GeometryFactory().createPolygon(
            new GeometryFactory().createLinearRing(toArray(closedPoints)),
            null);
    }

    protected boolean checkPolygon() throws NoninvertibleTransformException {
        if (getCoordinates().size() < 3) {
            getPanel().getContext().warnUser("The polygon must have at least 3 points");

            return false;
        }

        IsValidOp isValidOp = new IsValidOp(getPolygon());

        if (!isValidOp.isValid()) {
            getPanel().getContext().warnUser(isValidOp.getValidationError().getMessage());

            if (getWorkbench()
                .getBlackboard()
                .get(EditTransaction.ROLLING_BACK_INVALID_EDITS_KEY, false)) {
                return false;
            }
        }

        return true;
    }
}