// $Id: ChildGenUML.java,v 1.16 2004/08/29 11:48:45 mvw Exp $
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// File: ChildGenUML.java
// Classes: ChildGenUML
// Original Author: jrobbins
// $Id: ChildGenUML.java,v 1.16 2004/08/29 11:48:45 mvw Exp $

package org.argouml.uml.cognitive.critics;

import java.util.Collection;
import org.apache.log4j.Logger;

import java.util.Enumeration;
import java.util.Vector;
import org.argouml.kernel.Project;
import org.argouml.model.ModelFacade;
import org.argouml.model.uml.UmlHelper;

import org.tigris.gef.base.Diagram;
import org.tigris.gef.util.ChildGenerator;
import org.tigris.gef.util.EnumerationComposite;
import org.tigris.gef.util.EnumerationEmpty;
import org.tigris.gef.util.EnumerationSingle;

/** This class gives critics access to parts of the UML model of the
 *  design.  It defines a gen() function that returns the "children"
 *  of any given part of the UML model.  Basically, it goes from
 *  Project, to Models, to ModelElements.  Argo's critic Agency uses
 *  this to apply critics where appropriate.
 * @see org.argouml.cognitive.critics.Agency 
 * @see org.argouml.cognitive.Designer
 */

public class ChildGenUML implements ChildGenerator {

    private static final Logger LOG = Logger.getLogger(ChildGenUML.class);
    
    /** Reply a java.util.Enumeration of the children of the given Object 
     * TODO: GEF has moved away from vectors to collections
     * returning an iterator would now seem better.
     *
     * @see org.tigris.gef.util.ChildGenerator#gen(java.lang.Object)
     */
    public Enumeration gen(Object o) {
        
        if (o == null) LOG.debug("Object is null");
        else LOG.debug("Findin g children for " + o.getClass());
        
	if (o instanceof Project) {
	    Project p = (Project) o;
	    return new EnumerationComposite(p.getUserDefinedModels().elements(),
					    p.getDiagrams().elements());
	}

	if (o instanceof Diagram) {
	    Collection figs = ((Diagram) o).getLayer().getContents(null);
	    if (figs != null) return new Vector(figs).elements();
	}

	if (ModelFacade.isAPackage(o)) {
	    Vector ownedElements =
		new Vector(ModelFacade.getOwnedElements(o));
	    if (ownedElements != null) return ownedElements.elements();
	}

	if (ModelFacade.isAElementImport(o)) {
	    Object me = ModelFacade.getModelElement(o);
	    return new EnumerationSingle(me);  //wasteful!
	}

	
	// TODO: associationclasses fit both of the next 2 cases

	if (ModelFacade.isAClassifier(o)) {
	    EnumerationComposite res = new EnumerationComposite();
	    res.addSub(new Vector(ModelFacade.getFeatures(o)));
            
	    Vector sms = new Vector(ModelFacade.getBehaviors(o));
	    //Object sm = null;
	    //if (sms != null && sms.size() > 0)
		//sm = sms.elementAt(0);
	    //if (sm != null) res.addSub(new EnumerationSingle(sm));
            if (sms != null)
                    res.addSub(sms.elements());
	    return res;
	}

	if (ModelFacade.isAAssociation(o)) {
	    Vector assocEnds = new Vector(ModelFacade.getConnections(o));
	    if (assocEnds != null) return assocEnds.elements();
	    //TODO: MAssociationRole
	}

	// // needed?
	if (ModelFacade.isAStateMachine(o)) {
	    EnumerationComposite res = new EnumerationComposite();
	    Object top = UmlHelper.getHelper().getStateMachines().getTop(o);
	    if (top != null) res.addSub(new EnumerationSingle(top));
	    res.addSub(new Vector(ModelFacade.getTransitions(o)));
	    return res;
	}

	// needed?
	if (ModelFacade.isACompositeState(o)) {
	    Vector substates = new Vector(ModelFacade.getSubvertices(o));
	    if (substates != null) return substates.elements();
	}

        if (ModelFacade.isAOperation(o)) {
            Vector params = new Vector(ModelFacade.getParameters(o));
            if (params != null) return params.elements();
        }
        
        if (ModelFacade.isAModelElement(o)) {
	    Vector behavior = new Vector(ModelFacade.getBehaviors(o));
	    if (behavior != null) return behavior.elements();
	}

	// tons more cases
        LOG.debug("No children found for: " + o.getClass());

	return EnumerationEmpty.theInstance();
    }
} /* end class ChildGenUML */