// $Id: UMLModelElementNamespaceComboBoxModel.java,v 1.16 2004/09/20 15:28:44 mvw Exp $
// Copyright (c) 1996-2003 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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package org.argouml.uml.ui.foundation.core;

import org.argouml.model.ModelFacade;
import org.argouml.model.uml.UmlModelEventPump;
import org.argouml.model.uml.foundation.core.CoreHelper;
import org.argouml.uml.ui.UMLComboBoxModel2;

/**
 * A model for a namespace combo box,
 *
 * @since Oct 10, 2002
 * @author jaap.branderhorst@xs4all.nl, alexb
 */
public class UMLModelElementNamespaceComboBoxModel extends UMLComboBoxModel2 {
    
    private static UMLModelElementNamespaceComboBoxModel theInstance;
    
    
    /**
     * Constructor for UMLModelElementNamespaceComboBoxModel.
     */
    public UMLModelElementNamespaceComboBoxModel() {
        super("namespace", false);
        UmlModelEventPump.getPump().addClassModelEventListener(this, 
                (Class) ModelFacade.NAMESPACE, "ownedElement");
    }
    
    /**
     * @see org.argouml.uml.ui.UMLComboBoxModel2#isValidElement(Object)
     */
    protected boolean isValidElement(Object o) {
        return org.argouml.model.ModelFacade.isANamespace(o) 
        && CoreHelper.getHelper().isValidNamespace(
                /*(MModelElement)*/ getTarget(), /*(MNamespace)*/ o);
    }
    
    /**  
     * @see org.argouml.uml.ui.UMLComboBoxModel2#buildModelList()
     */
    protected void buildModelList() {
        setElements(CoreHelper.getHelper()
		    .getAllPossibleNamespaces(/*(MModelElement)*/ getTarget()));
    }
    
    /**
     * @see org.argouml.uml.ui.UMLComboBoxModel2#getSelectedModelElement()
     */
    protected Object getSelectedModelElement() {
        if (getTarget() != null) {
            return ModelFacade.getNamespace(getTarget());
        }
        return null;
    }
       
}