/*******************************************************************************
* Copyright (c) 2003, 2007 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;
/**
* Performs a graph layout on a <code>CompoundDirectedGraph</code>. The input format is
* the same as for {@link DirectedGraphLayout}. All nodes, including subgraphs and their
* children, should be added to the {@link DirectedGraph#nodes} field.
* <P>
* The requirements for this algorithm are the same as those of
* <code>DirectedGraphLayout</code>, with the following exceptions:
* <UL>
* <LI>There is an implied edge between a subgraph and each of its member nodes. These
* edges form the containment graph <EM>T</EM>. Thus, the compound directed graph
* <EM>CG</EM> is said to be connected iff Union(<EM>G</EM>, <EM>T</EM>) is connected,
* where G represents the given nodes (including subgraphs) and edges.
*
* <LI>This algorithm will remove any compound cycles found in the input graph
* <em>G</em> by inverting edges according to a heuristic until no more cycles are
* found. A compound cycle is defined as: a cycle comprised of edges from <EM>G</EM>,
* <EM>T</EM>, and <em>T<SUP>-1</SUP></em>, in the form
* (c<SUP>*</SUP>e<SUP>+</SUP>p<SUP>*</SUP>e<SUP>+</SUP>)*, where
* <em>T<SUP>-1</SUP></em> is the backwards graph of <EM>T</EM>, c element of T, e
* element of G, and p element of T<SUP>-1</SUP>.
* </UL>
*
* @author Randy Hudson
* @since 2.1.2
*/
public final class CompoundDirectedGraphLayout extends DirectedGraphLayout {
void init() {
steps.add(new TransposeMetrics());
steps.add(new CompoundBreakCycles());
steps.add(new RouteEdges());
steps.add(new ConvertCompoundGraph());
steps.add(new InitialRankSolver());
steps.add(new TightSpanningTreeSolver());
steps.add(new RankAssignmentSolver());
steps.add(new CompoundPopulateRanks());
steps.add(new CompoundVerticalPlacement());
steps.add(new MinCross(new CompoundRankSorter()));
steps.add(new SortSubgraphs());
steps.add(new CompoundHorizontalPlacement());
}
}