bp-scopviz/scopviz/src/main/java/de/tu_darmstadt/informatik/tk/scopviz/io/MySourceBase.java

/*This is a modified version of the class org.graphstream.stream.SourceBase
 * It was modified by Jascha Bohne <jaschabohne@web.de> for use in the scopviz project
 * This class is based on the 1.3 release of graphstream 
 *
 * Copyright 2006 - 2015
 *     Stefan Balev     <stefan.balev@graphstream-project.org>
 *     Julien Baudry    <julien.baudry@graphstream-project.org>
 *     Antoine Dutot    <antoine.dutot@graphstream-project.org>
 *     Yoann Pigné      <yoann.pigne@graphstream-project.org>
 *     Guilhelm Savin   <guilhelm.savin@graphstream-project.org>
 * 
 * This file is part of GraphStream <http://graphstream-project.org>.
 * 
 * GraphStream is a library whose purpose is to handle static or dynamic
 * graph, create them from scratch, file or any source and display them.
 * 
 * This program is free software distributed under the terms of two licenses, the
 * CeCILL-C license that fits European law, and the GNU Lesser General Public
 * License. You can  use, modify and/ or redistribute the software under the terms
 * of the CeCILL-C license as circulated by CEA, CNRS and INRIA at the following
 * URL <http://www.cecill.info> or under the terms of the GNU LGPL as published by
 * the Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 * 
 * This program 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 GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * The fact that you are presently reading this means that you have had
 * knowledge of the CeCILL-C and LGPL licenses and that you accept their terms.
 */
package de.tu_darmstadt.informatik.tk.scopviz.io;

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Stack;

import org.graphstream.graph.implementations.AbstractElement.AttributeChangeEvent;
import org.graphstream.stream.AttributeSink;
import org.graphstream.stream.ElementSink;
import org.graphstream.stream.Sink;
import org.graphstream.stream.Source;
import org.graphstream.stream.sync.SourceTime;

import de.tu_darmstadt.informatik.tk.scopviz.debug.Debug;
import de.tu_darmstadt.informatik.tk.scopviz.graphs.MyGraph;

/**
 * Base implementation of an input that provide basic sink handling.
 * 
 * <p>
 * This implementation can register a set of graph sinks (or separate sets of
 * attributes or elements sinks) and provides protected methods to easily
 * broadcast events to all the sinks (beginning with "send").
 * </p>
 * 
 * <p>
 * Each time you want to produce an event toward all registered sinks, you call
 * one of the "send*" methods with correct parameters. The parameters of the
 * "send*" methods maps to the usual GraphStream events.
 * </p>
 * 
 * <p>
 * This class is "reentrant". This means that if a send*() method is called
 * during the execution of another or the same send*() method, the event is
 * deferred until the first send*() method is finished. This avoid recursive
 * loops if a sink modifies the input during event handling.
 * </p>
 */
public class MySourceBase implements Source {
	// Attribute

	/**
	 * if the programm is currently reading a multigraph
	 */
	protected boolean multiGraph = false;

	/**
	 * @return if the last read Graph was a multigraph
	 */
	public boolean wasMultiGraph() {
		return multiGraph;
	}

	/**
	 * the sink of the complete Graph
	 */
	protected Sink originalSink;

	/**
	 * Enum of the different possible Types of Elements.
	 */
	public enum ElementType {
		NODE, EDGE, GRAPH
	};

	/**
	 * Set of graph attributes sinks.
	 */
	protected ArrayList<AttributeSink> attrSinks = new ArrayList<AttributeSink>();

	/**
	 * Set of graph elements sinks.
	 */
	protected ArrayList<ElementSink> eltsSinks = new ArrayList<ElementSink>();

	/**
	 * A queue that allow the management of events (nodes/edge
	 * add/delete/change) in the right order.
	 */
	protected LinkedList<GraphEvent> eventQueue = new LinkedList<GraphEvent>();

	/**
	 * A boolean that indicates whether or not an Sink event is being sent
	 * during another one.
	 */
	protected boolean eventProcessing = false;

	/**
	 * Id of this source.
	 */
	protected String sourceId;

	/**
	 * Time of this source.
	 */
	protected SourceTime sourceTime;

	/**
	 * a List of all inner Graphs of a multigraphFile.
	 */
	protected LinkedList<MyGraph> subGraphs = new LinkedList<>();

	/**
	 * all inner graphs that are currently being edited.
	 */
	protected Stack<MyGraph> usedSubGraphs = new Stack<>();

	/**
	 * the ID of the (last added) outer Graph.
	 */
	protected String superID = "";

	// Construction

	/**
	 * Creates a new MySourceBase Object with a random ID.
	 */
	protected MySourceBase() {
		this(String.format("sourceOnThread#%d_%d", Thread.currentThread().getId(),
				System.currentTimeMillis() + ((int) (Math.random() * 1000))));
	}

	/**
	 * Creates a new MySourceBase Object with a given ID.
	 * 
	 * @param sourceId
	 *            the ID to use
	 */
	protected MySourceBase(String sourceId) {
		this.sourceId = sourceId;
		this.sourceTime = new SourceTime(sourceId);
	}

	// Access

	/**
	 * Returns an Iterable over all the attribute sinks.
	 * 
	 * @return the Iterable
	 */
	public Iterable<AttributeSink> attributeSinks() {
		return attrSinks;
	}

	/**
	 * Returns an Iterable over all the element sinks.
	 * 
	 * @return the Iterable
	 */
	public Iterable<ElementSink> elementSinks() {
		return eltsSinks;
	}

	// Command

	@Override
	public void addSink(Sink sink) {
		multiGraph = false;
		originalSink = sink;
		addAttributeSink(sink);
		addElementSink(sink);
		resetSubGraphs();
		try {
			superID = ((MyGraph) sink).getId();
		} catch (Exception e) {
			Debug.out(e.toString() + "\n" + e.getStackTrace().toString());
		}
	}

	/**
	 * Adds a new Sink that works with SubGraphs.
	 * 
	 * @param sink
	 *            the Sink to add
	 */
	private void addSubGraphSink(Sink sink) {
		addAttributeSink(sink);
		addElementSink(sink);
	}

	@Override
	public void addAttributeSink(AttributeSink sink) {
		if (!eventProcessing) {
			eventProcessing = true;
			manageEvents();

			attrSinks.add(sink);

			manageEvents();
			eventProcessing = false;
		} else {
			eventQueue.add(new AddToListEvent<AttributeSink>(attrSinks, sink));
		}
	}

	@Override
	public void addElementSink(ElementSink sink) {
		if (!eventProcessing) {
			eventProcessing = true;
			manageEvents();

			eltsSinks.add(sink);

			manageEvents();
			eventProcessing = false;
		} else {
			eventQueue.add(new AddToListEvent<ElementSink>(eltsSinks, sink));
		}
	}

	@Override
	public void clearSinks() {
		clearElementSinks();
		clearAttributeSinks();
	}

	@Override
	public void clearElementSinks() {
		if (!eventProcessing) {
			eventProcessing = true;
			manageEvents();

			eltsSinks.clear();

			manageEvents();
			eventProcessing = false;
		} else {
			eventQueue.add(new ClearListEvent<ElementSink>(eltsSinks));
		}
	}

	@Override
	public void clearAttributeSinks() {
		if (!eventProcessing) {
			eventProcessing = true;
			manageEvents();

			attrSinks.clear();

			manageEvents();
			eventProcessing = false;
		} else {
			eventQueue.add(new ClearListEvent<AttributeSink>(attrSinks));
		}
	}

	@Override
	public void removeSink(Sink sink) {
		removeAttributeSink(sink);
		removeElementSink(sink);
	}

	@Override
	public void removeAttributeSink(AttributeSink sink) {
		if (!eventProcessing) {
			eventProcessing = true;
			manageEvents();

			attrSinks.remove(sink);

			manageEvents();
			eventProcessing = false;
		} else {
			eventQueue.add(new RemoveFromListEvent<AttributeSink>(attrSinks, sink));
		}
	}

	@Override
	public void removeElementSink(ElementSink sink) {
		if (!eventProcessing) {
			eventProcessing = true;
			manageEvents();

			eltsSinks.remove(sink);

			manageEvents();
			eventProcessing = false;
		} else {
			eventQueue.add(new RemoveFromListEvent<ElementSink>(eltsSinks, sink));
		}
	}

	/**
	 * Send a "graph cleared" event to all element sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 */
	public void sendGraphCleared(String sourceId) {
		sendGraphCleared(sourceId, sourceTime.newEvent());
	}

	/**
	 * Send a "graph cleared" event to all element sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param timeId
	 */
	public void sendGraphCleared(String sourceId, long timeId) {
		if (!eventProcessing) {
			eventProcessing = true;
			manageEvents();

			for (int i = 0; i < eltsSinks.size(); i++) {
				eltsSinks.get(i).graphCleared(sourceId, timeId);
			}
			manageEvents();
			eventProcessing = false;
		} else {
			eventQueue.add(new BeforeGraphClearEvent(sourceId, timeId));
		}
	}

	/**
	 * Send a "step begins" event to all element sinks.
	 * 
	 * @param sourceId
	 *            The graph identifier.
	 * @param step
	 *            The step time stamp.
	 */
	public void sendStepBegins(String sourceId, double step) {
		sendStepBegins(sourceId, sourceTime.newEvent(), step);
	}

	/**
	 * Send a "step begins" event to all element sinks.
	 * 
	 * @param sourceId
	 *            The graph identifier.
	 * @param timeId
	 * @param step
	 */
	public void sendStepBegins(String sourceId, long timeId, double step) {
		if (!eventProcessing) {
			eventProcessing = true;
			manageEvents();

			for (int i = 0; i < eltsSinks.size(); i++) {
				eltsSinks.get(i).stepBegins(sourceId, timeId, step);
			}
			manageEvents();
			eventProcessing = false;
		} else {
			eventQueue.add(new StepBeginsEvent(sourceId, timeId, step));
		}
	}

	/**
	 * Send a "node added" event to all element sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param nodeId
	 *            The node identifier.
	 */
	public void sendNodeAdded(String sourceId, String nodeId) {
		sendNodeAdded(sourceId, sourceTime.newEvent(), nodeId);
	}

	/**
	 * Send a "node added" event to all element sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param timeId
	 * @param nodeId
	 *            The node identifier.
	 */
	public void sendNodeAdded(String sourceId, long timeId, String nodeId) {
		if (!eventProcessing) {
			eventProcessing = true;
			manageEvents();

			for (int i = 0; i < eltsSinks.size(); i++) {
				eltsSinks.get(i).nodeAdded(sourceId, timeId, nodeId);
			}
			manageEvents();
			eventProcessing = false;
		} else {
			eventQueue.add(new AfterNodeAddEvent(sourceId, timeId, nodeId));
		}
	}

	/**
	 * Send a "node removed" event to all element sinks.
	 * 
	 * @param sourceId
	 *            The graph identifier.
	 * @param nodeId
	 *            The node identifier.
	 */
	public void sendNodeRemoved(String sourceId, String nodeId) {
		sendNodeRemoved(sourceId, sourceTime.newEvent(), nodeId);
	}

	/**
	 * Send a "node removed" event to all element sinks.
	 * 
	 * @param sourceId
	 *            The graph identifier.
	 * @param timeId
	 * @param nodeId
	 *            The node identifier.
	 */
	public void sendNodeRemoved(String sourceId, long timeId, String nodeId) {
		if (!eventProcessing) {
			eventProcessing = true;
			manageEvents();

			for (int i = 0; i < eltsSinks.size(); i++) {
				eltsSinks.get(i).nodeRemoved(sourceId, timeId, nodeId);
			}
			manageEvents();
			eventProcessing = false;
		} else {
			eventQueue.add(new BeforeNodeRemoveEvent(sourceId, timeId, nodeId));
		}
	}

	/**
	 * Send an "edge added" event to all element sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param edgeId
	 *            The edge identifier.
	 * @param fromNodeId
	 *            The edge start node.
	 * @param toNodeId
	 *            The edge end node.
	 * @param directed
	 *            Is the edge directed?.
	 */
	public void sendEdgeAdded(String sourceId, String edgeId, String fromNodeId, String toNodeId, boolean directed) {
		sendEdgeAdded(sourceId, sourceTime.newEvent(), edgeId, fromNodeId, toNodeId, directed);
	}

	/**
	 * Send an "edge added" event to all element sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param timeId
	 * @param edgeId
	 *            The edge identifier.
	 * @param fromNodeId
	 *            The edge start node.
	 * @param toNodeId
	 *            The edge end node.
	 * @param directed
	 *            Is the edge directed?.
	 */
	public void sendEdgeAdded(String sourceId, long timeId, String edgeId, String fromNodeId, String toNodeId,
			boolean directed) {
		if (!eventProcessing) {
			eventProcessing = true;
			manageEvents();

			for (int i = 0; i < eltsSinks.size(); i++) {
				eltsSinks.get(i).edgeAdded(sourceId, timeId, edgeId, fromNodeId, toNodeId, directed);
			}
			manageEvents();
			eventProcessing = false;
		} else {
			eventQueue.add(new AfterEdgeAddEvent(sourceId, timeId, edgeId, fromNodeId, toNodeId, directed));
		}
	}

	/**
	 * Send a "edge removed" event to all element sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param edgeId
	 *            The edge identifier.
	 */
	public void sendEdgeRemoved(String sourceId, String edgeId) {
		sendEdgeRemoved(sourceId, sourceTime.newEvent(), edgeId);
	}

	/**
	 * Send a "edge removed" event to all element sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param timeId
	 * @param edgeId
	 *            The edge identifier.
	 */
	public void sendEdgeRemoved(String sourceId, long timeId, String edgeId) {
		if (!eventProcessing) {
			eventProcessing = true;
			manageEvents();

			for (int i = 0; i < eltsSinks.size(); i++) {
				eltsSinks.get(i).edgeRemoved(sourceId, timeId, edgeId);
			}
			manageEvents();
			eventProcessing = false;
		} else {
			eventQueue.add(new BeforeEdgeRemoveEvent(sourceId, timeId, edgeId));
		}
	}

	/**
	 * Send a "edge attribute added" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param edgeId
	 *            The edge identifier.
	 * @param attribute
	 *            The attribute name.
	 * @param value
	 *            The attribute value.
	 */
	public void sendEdgeAttributeAdded(String sourceId, String edgeId, String attribute, Object value) {
		sendAttributeChangedEvent(sourceId, edgeId, ElementType.EDGE, attribute, AttributeChangeEvent.ADD, null, value);
	}

	/**
	 * Send a "edge attribute added" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param timeId
	 * @param edgeId
	 *            The edge identifier.
	 * @param attribute
	 *            The attribute name.
	 * @param value
	 *            The attribute value.
	 */
	public void sendEdgeAttributeAdded(String sourceId, long timeId, String edgeId, String attribute, Object value) {
		sendAttributeChangedEvent(sourceId, timeId, edgeId, ElementType.EDGE, attribute, AttributeChangeEvent.ADD, null,
				value);
	}

	/**
	 * Send a "edge attribute changed" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param edgeId
	 *            The edge identifier.
	 * @param attribute
	 *            The attribute name.
	 * @param oldValue
	 *            The old attribute value.
	 * @param newValue
	 *            The new attribute value.
	 */
	public void sendEdgeAttributeChanged(String sourceId, String edgeId, String attribute, Object oldValue,
			Object newValue) {
		sendAttributeChangedEvent(sourceId, edgeId, ElementType.EDGE, attribute, AttributeChangeEvent.CHANGE, oldValue,
				newValue);
	}

	/**
	 * Send a "edge attribute changed" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param timeId
	 * @param edgeId
	 *            The edge identifier.
	 * @param attribute
	 *            The attribute name.
	 * @param oldValue
	 *            The old attribute value.
	 * @param newValue
	 *            The new attribute value.
	 */
	public void sendEdgeAttributeChanged(String sourceId, long timeId, String edgeId, String attribute, Object oldValue,
			Object newValue) {
		sendAttributeChangedEvent(sourceId, timeId, edgeId, ElementType.EDGE, attribute, AttributeChangeEvent.CHANGE,
				oldValue, newValue);
	}

	/**
	 * Send a "edge attribute removed" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param edgeId
	 *            The edge identifier.
	 * @param attribute
	 *            The attribute name.
	 */
	public void sendEdgeAttributeRemoved(String sourceId, String edgeId, String attribute) {
		sendAttributeChangedEvent(sourceId, edgeId, ElementType.EDGE, attribute, AttributeChangeEvent.REMOVE, null,
				null);
	}

	/**
	 * Send a "edge attribute removed" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param timeId
	 * @param edgeId
	 *            The edge identifier.
	 * @param attribute
	 *            The attribute name.
	 */
	public void sendEdgeAttributeRemoved(String sourceId, long timeId, String edgeId, String attribute) {
		sendAttributeChangedEvent(sourceId, timeId, edgeId, ElementType.EDGE, attribute, AttributeChangeEvent.REMOVE,
				null, null);
	}

	/**
	 * Send a "graph attribute added" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param attribute
	 *            The attribute name.
	 * @param value
	 *            The attribute value.
	 */
	public void sendGraphAttributeAdded(String sourceId, String attribute, Object value) {
		sendAttributeChangedEvent(sourceId, null, ElementType.GRAPH, attribute, AttributeChangeEvent.ADD, null, value);
	}

	/**
	 * Send a "graph attribute added" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param timeId
	 *            The time identifier.
	 * @param attribute
	 *            The attribute name.
	 * @param value
	 *            The attribute value.
	 */
	public void sendGraphAttributeAdded(String sourceId, long timeId, String attribute, Object value) {
		sendAttributeChangedEvent(sourceId, timeId, null, ElementType.GRAPH, attribute, AttributeChangeEvent.ADD, null,
				value);
	}

	/**
	 * Send a "graph attribute changed" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param attribute
	 *            The attribute name.
	 * @param oldValue
	 *            The attribute old value.
	 * @param newValue
	 *            The attribute new value.
	 */
	public void sendGraphAttributeChanged(String sourceId, String attribute, Object oldValue, Object newValue) {
		sendAttributeChangedEvent(sourceId, null, ElementType.GRAPH, attribute, AttributeChangeEvent.CHANGE, oldValue,
				newValue);
	}

	/**
	 * Send a "graph attribute changed" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param timeId
	 *            The time identifier.
	 * @param attribute
	 *            The attribute name.
	 * @param oldValue
	 *            The attribute old value.
	 * @param newValue
	 *            The attribute new value.
	 */
	public void sendGraphAttributeChanged(String sourceId, long timeId, String attribute, Object oldValue,
			Object newValue) {
		sendAttributeChangedEvent(sourceId, timeId, null, ElementType.GRAPH, attribute, AttributeChangeEvent.CHANGE,
				oldValue, newValue);
	}

	/**
	 * Send a "graph attribute removed" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param attribute
	 *            The attribute name.
	 */
	public void sendGraphAttributeRemoved(String sourceId, String attribute) {
		sendAttributeChangedEvent(sourceId, null, ElementType.GRAPH, attribute, AttributeChangeEvent.REMOVE, null,
				null);
	}

	/**
	 * Send a "graph attribute removed" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param timeId
	 *            The time identifier.
	 * @param attribute
	 *            The attribute name.
	 */
	public void sendGraphAttributeRemoved(String sourceId, long timeId, String attribute) {
		sendAttributeChangedEvent(sourceId, timeId, null, ElementType.GRAPH, attribute, AttributeChangeEvent.REMOVE,
				null, null);
	}

	/**
	 * Send a "node attribute added" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param nodeId
	 *            The node identifier.
	 * @param attribute
	 *            The attribute name.
	 * @param value
	 *            The attribute value.
	 */
	public void sendNodeAttributeAdded(String sourceId, String nodeId, String attribute, Object value) {
		sendAttributeChangedEvent(sourceId, nodeId, ElementType.NODE, attribute, AttributeChangeEvent.ADD, null, value);
	}

	/**
	 * Send a "node attribute added" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param timeId
	 *            The time identifier.
	 * @param nodeId
	 *            The node identifier.
	 * @param attribute
	 *            The attribute name.
	 * @param value
	 *            The attribute value.
	 */
	public void sendNodeAttributeAdded(String sourceId, long timeId, String nodeId, String attribute, Object value) {
		sendAttributeChangedEvent(sourceId, timeId, nodeId, ElementType.NODE, attribute, AttributeChangeEvent.ADD, null,
				value);
	}

	/**
	 * Send a "node attribute changed" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param nodeId
	 *            The node identifier.
	 * @param attribute
	 *            The attribute name.
	 * @param oldValue
	 *            The attribute old value.
	 * @param newValue
	 *            The attribute new value.
	 */
	public void sendNodeAttributeChanged(String sourceId, String nodeId, String attribute, Object oldValue,
			Object newValue) {
		sendAttributeChangedEvent(sourceId, nodeId, ElementType.NODE, attribute, AttributeChangeEvent.CHANGE, oldValue,
				newValue);
	}

	/**
	 * Send a "node attribute changed" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param timeId
	 *            The time identifier.
	 * @param nodeId
	 *            The node identifier.
	 * @param attribute
	 *            The attribute name.
	 * @param oldValue
	 *            The attribute old value.
	 * @param newValue
	 *            The attribute new value.
	 */
	public void sendNodeAttributeChanged(String sourceId, long timeId, String nodeId, String attribute, Object oldValue,
			Object newValue) {
		sendAttributeChangedEvent(sourceId, timeId, nodeId, ElementType.NODE, attribute, AttributeChangeEvent.CHANGE,
				oldValue, newValue);
	}

	/**
	 * Send a "node attribute removed" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param nodeId
	 *            The node identifier.
	 * @param attribute
	 *            The attribute name.
	 */
	public void sendNodeAttributeRemoved(String sourceId, String nodeId, String attribute) {
		sendAttributeChangedEvent(sourceId, nodeId, ElementType.NODE, attribute, AttributeChangeEvent.REMOVE, null,
				null);
	}

	/**
	 * Send a "node attribute removed" event to all attribute sinks.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param timeId
	 * @param nodeId
	 *            The node identifier.
	 * @param attribute
	 *            The attribute name.
	 */
	public void sendNodeAttributeRemoved(String sourceId, long timeId, String nodeId, String attribute) {
		sendAttributeChangedEvent(sourceId, timeId, nodeId, ElementType.NODE, attribute, AttributeChangeEvent.REMOVE,
				null, null);
	}

	/**
	 * Send a add/change/remove attribute event on an element. This method is a
	 * generic way of notifying of an attribute change and is equivalent to
	 * individual send*Attribute*() methods.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param eltId
	 *            The changed element identifier.
	 * @param eltType
	 *            The changed element type.
	 * @param attribute
	 *            The changed attribute.
	 * @param event
	 *            The add/change/remove action.
	 * @param oldValue
	 *            The old attribute value (null if the attribute is removed or
	 *            added).
	 * @param newValue
	 *            The new attribute value (null if removed).
	 */
	public void sendAttributeChangedEvent(String sourceId, String eltId, ElementType eltType, String attribute,
			AttributeChangeEvent event, Object oldValue, Object newValue) {
		sendAttributeChangedEvent(sourceId, sourceTime.newEvent(), eltId, eltType, attribute, event, oldValue,
				newValue);
	}

	/**
	 * Send a add/change/remove attribute event on an element. This method is a
	 * generic way of notifying of an attribute change and is equivalent to
	 * individual send*Attribute*() methods.
	 * 
	 * @param sourceId
	 *            The source identifier.
	 * @param timeId
	 *            The time identifier.
	 * @param eltId
	 *            The changed element identifier.
	 * @param eltType
	 *            The changed element type.
	 * @param attribute
	 *            The changed attribute.
	 * @param event
	 *            The add/change/remove action.
	 * @param oldValue
	 *            The old attribute value (null if the attribute is removed or
	 *            added).
	 * @param newValue
	 *            The new attribute value (null if removed).
	 */
	public void sendAttributeChangedEvent(String sourceId, long timeId, String eltId, ElementType eltType,
			String attribute, AttributeChangeEvent event, Object oldValue, Object newValue) {
		if (!eventProcessing) {
			eventProcessing = true;
			manageEvents();

			if (event == AttributeChangeEvent.ADD) {
				if (eltType == ElementType.NODE) {
					for (int i = 0; i < attrSinks.size(); i++) {
						attrSinks.get(i).nodeAttributeAdded(sourceId, timeId, eltId, attribute, newValue);
					}
				} else if (eltType == ElementType.EDGE) {
					for (int i = 0; i < attrSinks.size(); i++) {
						attrSinks.get(i).edgeAttributeAdded(sourceId, timeId, eltId, attribute, newValue);
					}
				} else {
					for (int i = 0; i < attrSinks.size(); i++) {
						attrSinks.get(i).graphAttributeAdded(sourceId, timeId, attribute, newValue);
					}
				}
			} else if (event == AttributeChangeEvent.REMOVE) {
				if (eltType == ElementType.NODE) {
					for (int i = 0; i < attrSinks.size(); i++) {
						attrSinks.get(i).nodeAttributeRemoved(sourceId, timeId, eltId, attribute);
					}
				} else if (eltType == ElementType.EDGE) {
					for (int i = 0; i < attrSinks.size(); i++) {
						attrSinks.get(i).edgeAttributeRemoved(sourceId, timeId, eltId, attribute);
					}
				} else {
					for (int i = 0; i < attrSinks.size(); i++) {
						attrSinks.get(i).graphAttributeRemoved(sourceId, timeId, attribute);
					}
				}
			} else {
				if (eltType == ElementType.NODE) {
					for (int i = 0; i < attrSinks.size(); i++) {
						attrSinks.get(i).nodeAttributeChanged(sourceId, timeId, eltId, attribute, oldValue, newValue);
					}
				} else if (eltType == ElementType.EDGE) {
					for (int i = 0; i < attrSinks.size(); i++) {
						attrSinks.get(i).edgeAttributeChanged(sourceId, timeId, eltId, attribute, oldValue, newValue);
					}
				} else {
					for (int i = 0; i < attrSinks.size(); i++) {
						attrSinks.get(i).graphAttributeChanged(sourceId, timeId, attribute, oldValue, newValue);
					}
				}
			}

			manageEvents();
			eventProcessing = false;
		} else {
			eventQueue.add(
					new AttributeChangedEvent(sourceId, timeId, eltId, eltType, attribute, event, oldValue, newValue));
		}
	}

	// Deferred event management

	/**
	 * If in "event processing mode", ensure all pending events are processed.
	 */
	protected void manageEvents() {
		if (eventProcessing) {
			while (!eventQueue.isEmpty()) {
				eventQueue.remove().trigger();
			}
		}
	}

	// Events Management

	/**
	 * Interface that provide general purpose classification for evens involved
	 * in graph modifications.
	 */
	abstract class GraphEvent {
		String sourceId;
		long timeId;

		GraphEvent(String sourceId, long timeId) {
			this.sourceId = sourceId;
			this.timeId = timeId;
		}

		abstract void trigger();
	}

	class AfterEdgeAddEvent extends GraphEvent {
		String edgeId;
		String fromNodeId;
		String toNodeId;
		boolean directed;

		AfterEdgeAddEvent(String sourceId, long timeId, String edgeId, String fromNodeId, String toNodeId,
				boolean directed) {
			super(sourceId, timeId);
			this.edgeId = edgeId;
			this.fromNodeId = fromNodeId;
			this.toNodeId = toNodeId;
			this.directed = directed;
		}

		@Override
		void trigger() {
			for (int i = 0; i < eltsSinks.size(); i++)
				eltsSinks.get(i).edgeAdded(sourceId, timeId, edgeId, fromNodeId, toNodeId, directed);
		}
	}

	class BeforeEdgeRemoveEvent extends GraphEvent {
		String edgeId;

		BeforeEdgeRemoveEvent(String sourceId, long timeId, String edgeId) {
			super(sourceId, timeId);
			this.edgeId = edgeId;
		}

		@Override
		void trigger() {
			for (int i = 0; i < eltsSinks.size(); i++)
				eltsSinks.get(i).edgeRemoved(sourceId, timeId, edgeId);
		}
	}

	class AfterNodeAddEvent extends GraphEvent {
		String nodeId;

		AfterNodeAddEvent(String sourceId, long timeId, String nodeId) {
			super(sourceId, timeId);
			this.nodeId = nodeId;
		}

		@Override
		void trigger() {
			for (int i = 0; i < eltsSinks.size(); i++)
				eltsSinks.get(i).nodeAdded(sourceId, timeId, nodeId);
		}
	}

	class BeforeNodeRemoveEvent extends GraphEvent {
		String nodeId;

		BeforeNodeRemoveEvent(String sourceId, long timeId, String nodeId) {
			super(sourceId, timeId);
			this.nodeId = nodeId;
		}

		@Override
		void trigger() {
			for (int i = 0; i < eltsSinks.size(); i++)
				eltsSinks.get(i).nodeRemoved(sourceId, timeId, nodeId);
		}
	}

	class BeforeGraphClearEvent extends GraphEvent {
		BeforeGraphClearEvent(String sourceId, long timeId) {
			super(sourceId, timeId);
		}

		@Override
		void trigger() {
			for (int i = 0; i < eltsSinks.size(); i++)
				eltsSinks.get(i).graphCleared(sourceId, timeId);
		}
	}

	class StepBeginsEvent extends GraphEvent {
		double step;

		StepBeginsEvent(String sourceId, long timeId, double step) {
			super(sourceId, timeId);
			this.step = step;
		}

		@Override
		void trigger() {
			for (int i = 0; i < eltsSinks.size(); i++)
				eltsSinks.get(i).stepBegins(sourceId, timeId, step);
		}
	}

	class AttributeChangedEvent extends GraphEvent {
		ElementType eltType;

		String eltId;

		String attribute;

		AttributeChangeEvent event;

		Object oldValue;

		Object newValue;

		AttributeChangedEvent(String sourceId, long timeId, String eltId, ElementType eltType, String attribute,
				AttributeChangeEvent event, Object oldValue, Object newValue) {
			super(sourceId, timeId);
			this.eltType = eltType;
			this.eltId = eltId;
			this.attribute = attribute;
			this.event = event;
			this.oldValue = oldValue;
			this.newValue = newValue;
		}

		@Override
		void trigger() {
			switch (event) {
			case ADD:
				switch (eltType) {
				case NODE:
					for (int i = 0; i < attrSinks.size(); i++)
						attrSinks.get(i).nodeAttributeAdded(sourceId, timeId, eltId, attribute, newValue);
					break;
				case EDGE:
					for (int i = 0; i < attrSinks.size(); i++)
						attrSinks.get(i).edgeAttributeAdded(sourceId, timeId, eltId, attribute, newValue);
					break;
				default:
					for (int i = 0; i < attrSinks.size(); i++)
						attrSinks.get(i).graphAttributeAdded(sourceId, timeId, attribute, newValue);
				}
				break;
			case REMOVE:
				switch (eltType) {
				case NODE:
					for (int i = 0; i < attrSinks.size(); i++)
						attrSinks.get(i).nodeAttributeRemoved(sourceId, timeId, eltId, attribute);
					break;
				case EDGE:
					for (int i = 0; i < attrSinks.size(); i++)
						attrSinks.get(i).edgeAttributeRemoved(sourceId, timeId, eltId, attribute);
					break;
				default:
					for (int i = 0; i < attrSinks.size(); i++)
						attrSinks.get(i).graphAttributeRemoved(sourceId, timeId, attribute);
				}
				break;
			default:
				switch (eltType) {
				case NODE:
					for (int i = 0; i < attrSinks.size(); i++)
						attrSinks.get(i).nodeAttributeChanged(sourceId, timeId, eltId, attribute, oldValue, newValue);
					break;
				case EDGE:
					for (int i = 0; i < attrSinks.size(); i++)
						attrSinks.get(i).edgeAttributeChanged(sourceId, timeId, eltId, attribute, oldValue, newValue);
					break;
				default:
					for (int i = 0; i < attrSinks.size(); i++)
						attrSinks.get(i).graphAttributeChanged(sourceId, timeId, attribute, oldValue, newValue);
				}
			}
		}
	}

	class AddToListEvent<T> extends GraphEvent {
		List<T> l;
		T obj;

		AddToListEvent(List<T> l, T obj) {
			super(null, -1);
			this.l = l;
			this.obj = obj;
		}

		@Override
		void trigger() {
			l.add(obj);
		}
	}

	class RemoveFromListEvent<T> extends GraphEvent {
		List<T> l;
		T obj;

		RemoveFromListEvent(List<T> l, T obj) {
			super(null, -1);
			this.l = l;
			this.obj = obj;
		}

		@Override
		void trigger() {
			l.remove(obj);
		}
	}

	class ClearListEvent<T> extends GraphEvent {
		List<T> l;

		ClearListEvent(List<T> l) {
			super(null, -1);
			this.l = l;
		}

		@Override
		void trigger() {
			l.clear();
		}
	}

	/**
	 * how many inner graphs were generated for the current graph
	 */
	private int subGraphCounter = 1;

	/**
	 * adds a new sub graph, it will be populated until InnerGraphFInished is
	 * called
	 */
	protected void newSubGraph() {
		if (subGraphCounter > 1) {
			Debug.out(originalSink.toString());
			removeSink(originalSink);
			multiGraph = true;
		}
		MyGraph g = new MyGraph(superID + "sub" + subGraphCounter);
		subGraphCounter++;
		addSubGraphSink(g);
		usedSubGraphs.push(g);
	}

	/**
	 * adds the sub Graph to the List of subGraphs and removes it from the
	 * sinkLists
	 */
	protected void subGraphFinished() {
		MyGraph g = usedSubGraphs.pop();
		removeSink(g);
		subGraphs.add(g);
	}

	/**
	 * this returns all finished subgraphs, but does not reset the internal
	 * dataStructures. This can be called until a new Graph is added using
	 * addSink().
	 * 
	 * @return all subGraphs
	 */
	public LinkedList<MyGraph> getSubGraphs() {
		return subGraphs;
	}

	/**
	 * resets the internal datastructures used for the subgraphs. This is
	 * automatically called with addGraph().
	 */
	protected void resetSubGraphs() {
		usedSubGraphs.removeAllElements();
		subGraphCounter = 1;
		subGraphs.clear();
	}

}