| /******************************************************************************* |
| * Copyright (c) 2000, 2010 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.draw2d; |
| |
| import org.eclipse.draw2d.geometry.Point; |
| import org.eclipse.draw2d.geometry.Rectangle; |
| |
| /** |
| * Similar to a {@link org.eclipse.draw2d.ChopboxAnchor}, except this anchor is |
| * located on the ellipse defined by the owners bounding box. |
| * |
| * @author Alex Selkov Created 31.08.2002 23:11:43 |
| */ |
| public class EllipseAnchor extends AbstractConnectionAnchor { |
| |
| /** |
| * @see org.eclipse.draw2d.AbstractConnectionAnchor#AbstractConnectionAnchor() |
| */ |
| public EllipseAnchor() { |
| } |
| |
| /** |
| * @see org.eclipse.draw2d.AbstractConnectionAnchor#AbstractConnectionAnchor(IFigure) |
| */ |
| public EllipseAnchor(IFigure owner) { |
| super(owner); |
| } |
| |
| /** |
| * Returns a point on the ellipse (defined by the owner's bounding box) |
| * where the connection should be anchored. |
| * |
| * @see org.eclipse.draw2d.ConnectionAnchor#getLocation(Point) |
| */ |
| public Point getLocation(Point reference) { |
| Rectangle r = Rectangle.SINGLETON; |
| r.setBounds(getOwner().getBounds()); |
| r.translate(-1, -1); |
| r.resize(1, 1); |
| getOwner().translateToAbsolute(r); |
| |
| Point ref = r.getCenter().negate().translate(reference); |
| |
| if (ref.x == 0) |
| return new Point(reference.x, (ref.y > 0) ? r.bottom() : r.y); |
| if (ref.y == 0) |
| return new Point((ref.x > 0) ? r.right() : r.x, reference.y); |
| |
| float dx = (ref.x > 0) ? 0.5f : -0.5f; |
| float dy = (ref.y > 0) ? 0.5f : -0.5f; |
| |
| // ref.x, ref.y, r.width, r.height != 0 => safe to proceed |
| |
| float k = (float) (ref.y * r.width) / (ref.x * r.height); |
| k = k * k; |
| |
| return r.getCenter().translate((int) (r.width * dx / Math.sqrt(1 + k)), |
| (int) (r.height * dy / Math.sqrt(1 + 1 / k))); |
| } |
| } |