Layout.java

/*
Copyright 2008-2010 Gephi
Authors : Helder Suzuki <heldersuzuki@gephi.org>
Website : http://www.gephi.org

This file is part of Gephi.

DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

Copyright 2011 Gephi Consortium. All rights reserved.

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"License"). You may not use this file except in compliance with the
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or /cddl-1.0.txt and /gpl-3.0.txt. See the License for the
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*/
package org.gephi.layout.spi;

import org.gephi.graph.api.GraphModel;

/**
 * A Layout algorithm should implement the <code>Layout</code> interface to allow the
 * <code>LayoutController</code> to run it properly.
 * <p>
 * See the <code>LayoutBuilder</code> documentation to know how layout should
 * be instanciated.
 * <p>
 * To have fully integrated properties that can be changed in real-time by users,
 * properly define the various <code>LayoutProperty</code> returned by the
 * {@link #getProperties()} method and provide getter and setter for each.
 *
 * @author Helder Suzuki <heldersuzuki@gephi.org>
 * @see LayoutBuilder
 */
public interface Layout {

    /**
     * initAlgo() is called to initialize the algorithm (prepare to run).
     */
    public void initAlgo();

    /**
     * Injects the graph model for the graph this Layout should operate on.
     * <p>
     * It's preferable to get <b>visible</b> graph to perform on visualization.
     * @param graphModel    the graph model that the layout is to be working on
     */
    public void setGraphModel(GraphModel graphModel);

    /**
     * Run a step in the algorithm, should be called only if canAlgo() returns
     * true.
     */
    public void goAlgo();

    /**
     * Tests if the algorithm can run, called before each pass.
     * @return              <code>true</code> if the algorithm can run, <code>
     *                      false</code> otherwise
     */
    public boolean canAlgo();

    /**
     * Called when the algorithm is finished (canAlgo() returns false).
     */
    public void endAlgo();

    /**
     * The properties for this layout.
     * @return              the layout properties
     * @throws NoSuchMethodException 
     */
    public LayoutProperty[] getProperties();

    /**
     * Resets the properties values to the default values.
     */
    public void resetPropertiesValues();

    /**
     * The reference to the LayoutBuilder that instanciated this Layout.
     * @return              the reference to the builder that builts this instance
     */
    public LayoutBuilder getBuilder();
}