/*******************************************************************************
 * Copyright (c) 2003, 2005 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.internal.graph;

import org.eclipse.draw2d.graph.DirectedGraph;
import org.eclipse.draw2d.graph.Edge;

/**
 * Inverts any edges which are marked as backwards or "feedback" edges.
 * 
 * @author Daniel Lee
 * @since 2.1.2
 */
public class InvertEdges extends GraphVisitor {

/**
 * 
 * @see GraphVisitor#visit(org.eclipse.draw2d.graph.DirectedGraph)
 */
public void visit(DirectedGraph g) {
	for (int i = 0; i < g.edges.size(); i++) {
		Edge e = g.edges.getEdge(i);
		if ( e.isFeedback && !( e.source instanceof VirtualNode ) 
				&& ! ( e.target instanceof VirtualNode ) ) {
			
			e.invert();
			e.isFeedback = false;
		}
		// Bug fix:
		// Don't invert edges with VirtualNodes because it is not done properly.
		// Do that at the end in BreakCycles.revisit() instead.
	}
}

}