net.schweerelos.parrot.ui.NodeWrapperPersistentLayoutImpl.java Source code

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Here is the source code for net.schweerelos.parrot.ui.NodeWrapperPersistentLayoutImpl.java

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/*
 * Copyright (C) 2011 Andrea Schweer
 *
 * This file is part of the Digital Parrot. 
 *
 * The Digital Parrot is free software; you can redistribute it and/or modify
 * it under the terms of the Eclipse Public License as published by the Eclipse
 * Foundation or its Agreement Steward, either version 1.0 of the License, or
 * (at your option) any later version.
 *
 * The Digital Parrot is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the Eclipse Public License for
 * more details.
 *
 * You should have received a copy of the Eclipse Public License along with the
 * Digital Parrot. If not, see http://www.eclipse.org/legal/epl-v10.html. 
 *
 */

package net.schweerelos.parrot.ui;

import java.awt.Dimension;
import java.awt.geom.Point2D;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import net.schweerelos.parrot.model.NodeWrapper;

import org.apache.commons.collections15.Factory;
import org.apache.commons.collections15.map.LazyMap;

import edu.uci.ics.jung.algorithms.layout.Layout;
import edu.uci.ics.jung.visualization.layout.ObservableCachingLayout;
import edu.uci.ics.jung.visualization.layout.PersistentLayout;
import edu.uci.ics.jung.visualization.util.Caching;
import edu.uci.ics.jung.visualization.util.ChangeEventSupport;

/**
 * Implementation of PersistentLayout for NodeWrappers -- which means it deals with the value of each vertex rather than the vertex itself.
 * Defers to another layout until 'restore' is called,
 * then it uses the saved vertex locations.
 * 
 * @author Andrea Schweer <schweer@cs.waikato.ac.nz>
 * 
 * @see edu.uci.ics.jung.visualization.layout.PersistentLayoutImpl<V, E>
 */
public class NodeWrapperPersistentLayoutImpl extends ObservableCachingLayout<NodeWrapper, NodeWrapper>
        implements PersistentLayout<NodeWrapper, NodeWrapper>, ChangeEventSupport, Caching {

    /** Maps NodeWrapper URIs to the location of their respective vertex. */
    protected Map<String, Point> uriToNodeLocation;
    /** Holds all vertices whose position has been locked. */
    protected Set<NodeWrapper> lockedVertices;
    /** Whether the graph is locked (stops the VisualizationViewer rendering thread). */
    protected boolean locked;

    public NodeWrapperPersistentLayoutImpl(Layout<NodeWrapper, NodeWrapper> delegate) {
        super(delegate);

        uriToNodeLocation = LazyMap.decorate(new HashMap<String, Point>(), new RandomPointFactory(getSize()));
        lockedVertices = new HashSet<NodeWrapper>();
        locked = false;
    }

    @Override
    public synchronized void persist(String fileName) throws IOException {
        uriToNodeLocation.clear();

        for (NodeWrapper vertex : getGraph().getVertices()) {
            Point p = new Point(transform(vertex));
            uriToNodeLocation.put(vertex.getOntResource().getURI(), p);
        }

        ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(fileName));
        oos.writeObject(uriToNodeLocation);
        oos.close();
    }

    @SuppressWarnings("unchecked")
    @Override
    public synchronized void restore(String fileName) throws IOException, ClassNotFoundException {
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream(fileName));
        uriToNodeLocation = (Map<String, Point>) ois.readObject();
        ois.close();

        initializeLocations();

        locked = true;
        fireStateChanged();
    }

    protected void initializeLocations() {
        for (NodeWrapper vertex : getGraph().getVertices()) {
            Point2D coord = delegate.transform(vertex);
            if (!lockedVertices.contains(vertex))
                initializeLocation(vertex, coord, getSize());
        }
    }

    protected void initializeLocation(NodeWrapper vertex, Point2D coord, Dimension size) {
        String uri = vertex.getOntResource().getURI();
        if (uri != null && !uri.isEmpty() && uriToNodeLocation.containsKey(uri)) {
            Point point = uriToNodeLocation.get(uri);
            coord.setLocation(point.x, point.y);
        } else {
            // TODO
        }
    }

    @Override
    public void lock(boolean locked) {
        this.locked = locked;
    }

    /*
     * (non-Javadoc)
     * 
     * @see edu.uci.ics.jung.visualization.Layout#incrementsAreDone()
     */
    @Override
    public boolean done() {
        return locked;
    }

    /*
     * (non-Javadoc)
     * 
     * @see edu.uci.ics.jung.visualization.Layout#lockVertex(edu.uci.ics.jung.graph.Vertex)
     */
    @Override
    public void lock(NodeWrapper vertex, boolean state) {
        lockedVertices.add(vertex);
        delegate.lock(vertex, state);
    }

    @SuppressWarnings("serial")
    public static class RandomPointFactory implements Factory<Point>, Serializable {

        Dimension d;

        public RandomPointFactory(Dimension d) {
            this.d = d;
        }

        public edu.uci.ics.jung.visualization.layout.PersistentLayout.Point create() {
            double x = Math.random() * d.width;
            double y = Math.random() * d.height;
            return new Point(x, y);
        }
    }
}