ShapeEdge.java

/*
 Violet - A program for editing UML diagrams.

 Copyright (C) 2007 Cay S. Horstmann (http://horstmann.com)
 Alexandre de Pellegrin (http://alexdp.free.fr);

 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
 */

package com.horstmann.violet.product.diagram.abstracts.edge;

import java.awt.BasicStroke;
import java.awt.Shape;
import java.awt.geom.Line2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;

import com.horstmann.violet.product.diagram.common.edge.ColorableEdge;

/**
 * A class that assumes that an edge can yield its shape and then takes advantage of the fact that containment testing can be done
 * by stroking the shape with a fat stroke. NOTE: Ideally, you should be able to draw the same shape that is used for containment
 * testing. However, in JDK 1.4, BasicStroke.createStrokedShape returns shitty-looking shapes.
 */
public abstract class ShapeEdge extends ColorableEdge
{
    /**
     * Returns the path that should be stroked to draw this edge. The path does not include arrow tips or labels.
     * 
     * @return a path along the edge
     */
    public abstract Shape getShape();

    @Override
    public Rectangle2D getBounds()
    {
        return getShape().getBounds();
    }

    public boolean contains(Point2D aPoint)
    {
        final double MAX_DIST = 10;

        // the end points may contain small node, so don't
        // match them
        Line2D conn = getConnectionPoints();
        if (aPoint.distance(conn.getP1()) <= MAX_DIST || aPoint.distance(conn.getP2()) <= MAX_DIST) return false;

        Shape p = getShape();
        BasicStroke fatStroke = new BasicStroke((float) (2 * MAX_DIST));
        Shape fatPath = fatStroke.createStrokedShape(p);
        return fatPath.contains(aPoint);
    }
}