// $Id: UMLMutableGraphSupport.java,v 1.12 2004/09/28 11:12:20 bobtarling Exp $
// Copyright (c) 1996-2004 The Regents of the University of California. All
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// software and its documentation without fee, and without a written
// agreement is hereby granted, provided that the above copyright notice
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package org.argouml.uml.diagram;

import org.argouml.model.ModelFacade;
import org.argouml.model.uml.UmlFactory;
import org.argouml.model.uml.UmlException;
import org.argouml.model.uml.UmlHelper;

import java.util.Hashtable;
import java.util.List;
import java.util.Vector;
import org.apache.log4j.Logger;

import org.tigris.gef.base.Editor;
import org.tigris.gef.base.Globals;
import org.tigris.gef.base.Mode;
import org.tigris.gef.base.ModeManager;
import org.tigris.gef.graph.MutableGraphSupport;


/**
 * UMLMutableGraphSupport is a helper class which extends
 * MutableGraphSupport to provide additional helper and common methods
 * for UML Diagrams.
 *
 * @author mkl@tigris.org
 * @since November 14, 2002, 10:20 PM
 */
public abstract class UMLMutableGraphSupport extends MutableGraphSupport {
    
    private static final Logger LOG =
	Logger.getLogger(UMLMutableGraphSupport.class);
    
    /** contains all the nodes in the graphmodel/diagram. */    
    private Vector nodes = new Vector();
    /** constains all the edges in the graphmodel/diagram. */    
    private Vector edges = new Vector();
    
    
    /** constructor.
     * @see org.tigris.gef.graph.MutableGraphSupport
     */    
    public UMLMutableGraphSupport() {
        super();
    }
    
    /** get all the nodes from the graphmodel/diagram
     * @see org.tigris.gef.graph.MutableGraphSupport#getNodes()
     * @return Vector of nodes in the graphmodel/diagram
     */    
    public List getNodes() { return nodes; }
    
    /** get all the edges from the graphmodel/diagram
     * @return Vector of edges in the graphmodel/diagram
     */    
    public List getEdges() { return edges; }
    
    
    /**
     * @see org.tigris.gef.graph.MutableGraphModel#containsNode(java.lang.Object)
     */
    public boolean containsNode(Object node) {
	return nodes.contains(node);
    }
    
    /**
     * @param edge the candidate edge
     * @return true if it is contained
     */
    public boolean constainsEdge(Object edge) {
	return edges.contains(edge);
    }
    
    /** remove a node from the diagram and notify GEF
     * @param node node to remove
     */    
    public void removeNode(Object node) {
	if (!containsNode(node)) return;
	nodes.removeElement(node);
	fireNodeRemoved(node);
    }
    
    /** remove an edge from the graphmodel and notify GEF
     * @param edge edge to remove
     */    
    public void removeEdge(Object edge) {
	if (!containsEdge(edge)) return;
	edges.removeElement(edge);
	fireEdgeRemoved(edge);
    }
    
    /**
     * Assume that anything can be connected to anything unless overridden
     * in a subclass.
     *
     * @see org.tigris.gef.graph.MutableGraphModel#canConnect(java.lang.Object, 
     * java.lang.Object)
     */
    public boolean canConnect(Object fromP, Object toP) {
        return true;
    }


    /** The connect method without specifying a connection
     * type is unavailable by default
     *
     * @see org.tigris.gef.graph.MutableGraphModel#connect(java.lang.Object, 
     * java.lang.Object)
     */
    public Object connect(Object fromPort, Object toPort) {        
        throw new UnsupportedOperationException("The connect method is "
						+ "not supported");
    }
    
    /**
     * @return the namespace of the diagram
     */
    public abstract Object getNamespace();

    /** Contruct and add a new edge of the given kind and connect
     * the given ports.
     *
     * @param fromPort   The originating port to connect
     *
     * @param toPort     The destination port to connect
     *
     * @param edgeClass  The NSUML type of edge to create.
     *
     * @return           The type of edge created (the same as
     *                   edgeClass if we succeeded,
     *                   null otherwise)
     */
    public Object connect(Object fromPort, Object toPort,
			  java.lang.Class edgeClass)
    {
        Object connection = null;
        try {
            // If this was an association then there will be relevant
            // information to fetch out of the mode arguments.  If it
            // not an association then these will be passed forward
            // harmlessly as null.
            Editor curEditor = Globals.curEditor();
            ModeManager modeManager = curEditor.getModeManager();
            Mode mode = (Mode) modeManager.top();
            Hashtable args = mode.getArgs();
            Object style = args.get("aggregation"); //MAggregationKind
            Boolean unidirectional = (Boolean) args.get("unidirectional");
            // Create the UML connection of the given type between the
            // given model elements.
	    // default aggregation (none)
            connection =
		UmlFactory.getFactory().buildConnection(edgeClass, fromPort,
							style, toPort,
							null, unidirectional);
        } catch (UmlException ex) {
            // fail silently as we expect users to accidentally drop
            // on to wrong component
        }
        
        if (connection == null) {
            LOG.debug("Cannot make a " + edgeClass.getName()
		      + " between a " + fromPort.getClass().getName()
		      + " and a " + toPort.getClass().getName());
            return null;
        }
        
        addEdge(connection);
        LOG.debug("Connection type" + edgeClass.getName()
		  + " made between a " + fromPort.getClass().getName()
		  + " and a " + toPort.getClass().getName());
        return connection;
    }
    
    
    /**
     * @see org.tigris.gef.graph.MutableGraphModel#canAddNode(java.lang.Object)
     */
    public boolean canAddNode(Object node) {
        if (node == null) return false;
        if (ModelFacade.isAComment(node)) return true;
        return false;
    }
    
    
    /**
     * @see org.tigris.gef.graph.MutableGraphModel#canAddEdge(java.lang.Object)
     */
    public boolean canAddEdge(Object edge) {   
        if (edge == null) {
            return false;
        }
       return (UmlFactory.getFactory().isConnectionValid(edge.getClass(), 
               UmlHelper.getHelper().getSource(edge), 
               UmlHelper.getHelper().getDestination(edge)));
    }
}