/* $Id: ModeCreateCommentEdge.java 17865 2010-01-12 20:45:26Z linus $
 *****************************************************************************
 * Copyright (c) 2009 Contributors - see below
 * 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:
 *    tfmorris
 *****************************************************************************
 *
 * Some portions of this file was previously release using the BSD License:
 */

// Copyright (c) 2005-2008 The Regents of the University of California. All
// Rights Reserved. Permission to use, copy, modify, and distribute this
// software and its documentation without fee, and without a written
// agreement is hereby granted, provided that the above copyright notice
// and this paragraph appear in all copies.  This software program and
// documentation are copyrighted by The Regents of the University of
// California. The software program and documentation are supplied "AS
// IS", without any accompanying services from The Regents. The Regents
// does not warrant that the operation of the program will be
// uninterrupted or error-free. The end-user understands that the program
// was developed for research purposes and is advised not to rely
// exclusively on the program for any reason.  IN NO EVENT SHALL THE
// UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
// SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,
// ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
// THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY
// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
// PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
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// UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

package org.argouml.uml.diagram.ui;

import org.argouml.model.Model;
import org.argouml.uml.CommentEdge;
import org.tigris.gef.presentation.Fig;

/**
 * A Mode to interpret user input while creating a comment edge.
 * The comment can connect an existing comment node to any other existing
 * node or edge.
 */
public final class ModeCreateCommentEdge extends ModeCreateGraphEdge {
    
    /*
     * If we're drawing to an edge then only allow if the start is a comment
     * @see org.argouml.uml.diagram.ui.ModeCreateGraphEdge#isConnectionValid(org.tigris.gef.presentation.Fig, org.tigris.gef.presentation.Fig)
     */
    @Override
    protected final boolean isConnectionValid(Fig source, Fig dest) {
	if (dest instanceof FigNodeModelElement) {
	    Object srcOwner = source.getOwner();
	    Object dstOwner = dest.getOwner();
	    if (!Model.getFacade().isAModelElement(srcOwner)
                    || !Model.getFacade().isAModelElement(dstOwner)) {
                return false;
            }
	    if (Model.getModelManagementHelper().isReadOnly(srcOwner)
	            || Model.getModelManagementHelper().isReadOnly(dstOwner)) {
	        return false;
	    }
            return Model.getFacade().isAComment(srcOwner)
                    || Model.getFacade().isAComment(dstOwner);
	} else {
	    return true;
	}
    }

    protected final Object getMetaType() {
	return CommentEdge.class;
    }
}