| /******************************************************************************* |
| * Copyright (c) 2003, 2010 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.graph; |
| |
| import java.util.Stack; |
| |
| /** |
| * This class takes a DirectedGraph with an optimal rank assignment and a |
| * spanning tree, and populates the ranks of the DirectedGraph. Virtual nodes |
| * are inserted for edges that span 1 or more ranks. |
| * <P> |
| * Ranks are populated using a pre-order depth-first traversal of the spanning |
| * tree. For each node, all edges requiring virtual nodes are added to the |
| * ranks. |
| * |
| * @author Randy Hudson |
| * @since 2.1.2 |
| */ |
| class PopulateRanks extends GraphVisitor { |
| |
| private Stack changes = new Stack(); |
| |
| /** |
| * @see GraphVisitor#visit(DirectedGraph) |
| */ |
| public void visit(DirectedGraph g) { |
| if (g.forestRoot != null) { |
| for (int i = g.forestRoot.outgoing.size() - 1; i >= 0; i--) |
| g.removeEdge(g.forestRoot.outgoing.getEdge(i)); |
| g.removeNode(g.forestRoot); |
| } |
| g.ranks = new RankList(); |
| for (int i = 0; i < g.nodes.size(); i++) { |
| Node node = g.nodes.getNode(i); |
| g.ranks.getRank(node.rank).add(node); |
| } |
| for (int i = 0; i < g.nodes.size(); i++) { |
| Node node = g.nodes.getNode(i); |
| for (int j = 0; j < node.outgoing.size();) { |
| Edge e = node.outgoing.getEdge(j); |
| if (e.getLength() > 1) |
| changes.push(new VirtualNodeCreation(e, g)); |
| else |
| j++; |
| } |
| } |
| } |
| |
| /** |
| * @see GraphVisitor#revisit(DirectedGraph) |
| */ |
| public void revisit(DirectedGraph g) { |
| for (int r = 0; r < g.ranks.size(); r++) { |
| Rank rank = g.ranks.getRank(r); |
| Node prev = null, cur; |
| for (int n = 0; n < rank.size(); n++) { |
| cur = rank.getNode(n); |
| cur.left = prev; |
| if (prev != null) { |
| prev.right = cur; |
| } |
| prev = cur; |
| } |
| } |
| for (int i = 0; i < changes.size(); i++) { |
| RevertableChange change = (RevertableChange) changes.get(i); |
| change.revert(); |
| } |
| } |
| |
| } |