made future serialized class versions backwards compatible.

13 files changed, 249 insertions, 57 deletions

diff --git a/sources/core/VSProcess.java b/sources/core/VSProcess.java
index c6456de..9842321 100644
--- a/sources/core/VSProcess.java
+++ b/sources/core/VSProcess.java
@@ -1024,12 +1024,18 @@ public class VSProcess extends VSPrefs implements VSSerializable {
             System.out.println("Serializing: VSProcess (num: " + processNum
                                + "; id: " + processID + ")");
 
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
+
         objectOutputStream.writeObject(new Integer(processID));
         objectOutputStream.writeObject(new Integer(protocolsToReset.size()));
         for (VSAbstractProtocol protocol : protocolsToReset) {
             objectOutputStream.writeObject(protocol.getClassname());
             protocol.serialize(serialize, objectOutputStream);
         }
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
     }
 
     /* (non-Javadoc)
@@ -1046,6 +1052,9 @@ public class VSProcess extends VSPrefs implements VSSerializable {
         if (VSSerialize.DEBUG)
             System.out.println("Deserializing: VSProcess");
 
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
         this.processID = ((Integer)
                           objectInputStream.readObject()).intValue();
         int numProtocols = ((Integer)
@@ -1057,6 +1066,9 @@ public class VSProcess extends VSPrefs implements VSSerializable {
             protocol.deserialize(serialize, objectInputStream);
         }
 
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
         serialize.setObject(processNum, "process", this);
     }
 }
diff --git a/sources/core/VSTask.java b/sources/core/VSTask.java
index 1b8f744..c1323e8 100644
--- a/sources/core/VSTask.java
+++ b/sources/core/VSTask.java
@@ -362,6 +362,9 @@ public class VSTask implements Comparable, VSSerializable {
     public synchronized void serialize(VSSerialize serialize,
                                        ObjectOutputStream objectOutputStream)
     throws IOException {
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
+
         objectOutputStream.writeObject(new Integer(process.getProcessNum()));
         objectOutputStream.writeObject(event.getClassname());
         objectOutputStream.writeObject(new Integer(event.getID()));
@@ -370,6 +373,9 @@ public class VSTask implements Comparable, VSSerializable {
         objectOutputStream.writeObject(new Long(taskTime));
         objectOutputStream.writeObject(new Boolean(isGlobalTimed));
         objectOutputStream.writeObject(new Boolean(isProgrammed));
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
     }
 
     /* (non-Javadoc)
@@ -383,6 +389,9 @@ public class VSTask implements Comparable, VSSerializable {
         if (VSSerialize.DEBUG)
             System.out.println("Deserializing: VSTask");
 
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
         int processNum = ((Integer) objectInputStream.readObject()).intValue();
         VSProcess process = (VSProcess)
                             serialize.getObject(processNum, "process");
@@ -412,6 +421,9 @@ public class VSTask implements Comparable, VSSerializable {
         serialize.setObject(taskNum, "task", this);
         init(taskTime, process, event, !isGlobalTimed.booleanValue());
         this.isProgrammed = isProgrammed.booleanValue();
+
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
     }
 }
 
diff --git a/sources/core/VSTaskManager.java b/sources/core/VSTaskManager.java
index 272a52c..d4ee83c 100644
--- a/sources/core/VSTaskManager.java
+++ b/sources/core/VSTaskManager.java
@@ -503,6 +503,8 @@ public class VSTaskManager implements VSSerializable {
     public synchronized void serialize(VSSerialize serialize,
                                        ObjectOutputStream objectOutputStream)
     throws IOException {
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
 
         ArrayList<VSTask> tasks = new ArrayList<VSTask>();
 
@@ -526,6 +528,9 @@ public class VSTaskManager implements VSSerializable {
         objectOutputStream.writeObject(new Integer(tasks.size()));
         for (VSTask task : tasks)
             task.serialize(serialize, objectOutputStream);
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
     }
 
     /* (non-Javadoc)
@@ -539,6 +544,9 @@ public class VSTaskManager implements VSSerializable {
         if (VSSerialize.DEBUG)
             System.out.println("Deserializing: VSTaskManager");
 
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
         globalTasks.clear();
 
         ArrayList<VSProcess> processes = simulatorCanvas.getProcesses();
@@ -552,5 +560,8 @@ public class VSTaskManager implements VSSerializable {
             VSTask task = new VSTask(serialize, objectInputStream);
             addTask(task, task.isProgrammed());
         }
+
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
     }
 }
diff --git a/sources/events/VSAbstractEvent.java b/sources/events/VSAbstractEvent.java
index 0dd814c..0bc5ec8 100644
--- a/sources/events/VSAbstractEvent.java
+++ b/sources/events/VSAbstractEvent.java
@@ -177,9 +177,15 @@ abstract public class VSAbstractEvent extends VSPrefs {
         if (VSSerialize.DEBUG)
             System.out.println("Serializing: VSAbstractEvent; id="+getID());
 
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
+
         objectOutputStream.writeObject(new Integer(super.getID()));
         objectOutputStream.writeObject(eventShortname);
         objectOutputStream.writeObject(eventClassname);
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
     }
 
     /* (non-Javadoc)
@@ -195,6 +201,9 @@ abstract public class VSAbstractEvent extends VSPrefs {
         if (VSSerialize.DEBUG)
             System.out.print("Deserializing: VSAbstractEvent ");
 
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
         int id = ((Integer) objectInputStream.readObject()).intValue();
         this.eventShortname = (String) objectInputStream.readObject();
         this.eventClassname = (String) objectInputStream.readObject();
@@ -203,5 +212,8 @@ abstract public class VSAbstractEvent extends VSPrefs {
             System.out.println(eventClassname);
 
         serialize.setObject(id, "event", this);
+
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
     }
 }
diff --git a/sources/events/internal/VSMessageReceiveEvent.java b/sources/events/internal/VSMessageReceiveEvent.java
index 0cffa86..8972ce5 100644
--- a/sources/events/internal/VSMessageReceiveEvent.java
+++ b/sources/events/internal/VSMessageReceiveEvent.java
@@ -23,9 +23,12 @@
 
 package events.internal;
 
+import java.io.*;
+
 import core.VSMessage;
 import events.VSAbstractEvent;
 import protocols.VSAbstractProtocol;
+import serialize.VSSerialize;
 
 /**
  * The class VSMessageReceiveEvent. This event is used if a process receives
@@ -106,4 +109,41 @@ public class VSMessageReceiveEvent extends VSAbstractEvent {
 
         return true;
     }
+
+    /* (non-Javadoc)
+     * @see serialize.VSSerializable#serialize(serialize.VSSerialize,
+     *	java.io.ObjectOutputStream)
+     */
+    public synchronized void serialize(VSSerialize serialize,
+                                       ObjectOutputStream objectOutputStream)
+    throws IOException {
+        super.serialize(serialize, objectOutputStream);
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
+    }
+
+    /* (non-Javadoc)
+     * @see serialize.VSSerializable#deserialize(serialize.VSSerialize,
+     *	java.io.ObjectInputStream)
+     */
+    @SuppressWarnings("unchecked")
+    public synchronized void deserialize(VSSerialize serialize,
+                                         ObjectInputStream objectInputStream)
+    throws IOException, ClassNotFoundException {
+        super.deserialize(serialize, objectInputStream);
+
+        if (VSSerialize.DEBUG)
+            System.out.println("Deserializing: VSProtocolEvent");
+
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
+    }
 }
diff --git a/sources/events/internal/VSProtocolEvent.java b/sources/events/internal/VSProtocolEvent.java
index 5f5ceb4..8d6b2dd 100644
--- a/sources/events/internal/VSProtocolEvent.java
+++ b/sources/events/internal/VSProtocolEvent.java
@@ -27,7 +27,7 @@ import java.io.*;
 
 import events.*;
 import protocols.VSAbstractProtocol;
-import serialize.*;
+import serialize.VSSerialize;
 
 /**
  * The class VSProtocolEvent. This event is used if a protocol (server or
@@ -144,9 +144,16 @@ public class VSProtocolEvent extends VSAbstractEvent {
                                        ObjectOutputStream objectOutputStream)
     throws IOException {
         super.serialize(serialize, objectOutputStream);
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
+
         objectOutputStream.writeObject(protocolClassname);
         objectOutputStream.writeObject(new Boolean(isClientProtocol));
         objectOutputStream.writeObject(new Boolean(isProtocolActivation));
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
     }
 
     /* (non-Javadoc)
@@ -162,10 +169,17 @@ public class VSProtocolEvent extends VSAbstractEvent {
         if (VSSerialize.DEBUG)
             System.out.println("Deserializing: VSProtocolEvent");
 
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
         protocolClassname = (String) objectInputStream.readObject();
         isClientProtocol = ((Boolean)
                             objectInputStream.readObject()).booleanValue();;
         isProtocolActivation = ((Boolean)
                                 objectInputStream.readObject()).booleanValue();;
+
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
     }
 }
diff --git a/sources/events/internal/VSProtocolScheduleEvent.java b/sources/events/internal/VSProtocolScheduleEvent.java
index 912b552..99ae020 100644
--- a/sources/events/internal/VSProtocolScheduleEvent.java
+++ b/sources/events/internal/VSProtocolScheduleEvent.java
@@ -23,8 +23,11 @@
 
 package events.internal;
 
+import java.io.*;
+
 import events.*;
 import protocols.VSAbstractProtocol;
+import serialize.VSSerialize;
 
 /**
  * The class VSProtocolScheduleEvent. This event is used if a protocol (which
@@ -110,4 +113,38 @@ public class VSProtocolScheduleEvent extends VSAbstractEvent {
         else
             protocol.onClientScheduleStart();
     }
+
+    /* (non-Javadoc)
+     * @see serialize.VSSerializable#serialize(serialize.VSSerialize,
+     *	java.io.ObjectOutputStream)
+     */
+    public synchronized void serialize(VSSerialize serialize,
+                                       ObjectOutputStream objectOutputStream)
+    throws IOException {
+        super.serialize(serialize, objectOutputStream);
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
+    }
+
+    /* (non-Javadoc)
+     * @see serialize.VSSerializable#deserialize(serialize.VSSerialize,
+     *	java.io.ObjectInputStream)
+     */
+    @SuppressWarnings("unchecked")
+    public synchronized void deserialize(VSSerialize serialize,
+                                         ObjectInputStream objectInputStream)
+    throws IOException, ClassNotFoundException {
+        super.deserialize(serialize, objectInputStream);
+
+        if (VSSerialize.DEBUG)
+            System.out.println("Deserializing: VSProtocolEvent");
+
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
+    }
 }
diff --git a/sources/prefs/VSPrefs.java b/sources/prefs/VSPrefs.java
index de1c249..f17732c 100644
--- a/sources/prefs/VSPrefs.java
+++ b/sources/prefs/VSPrefs.java
@@ -944,14 +944,21 @@ public class VSPrefs implements VSSerializable {
     public synchronized void serialize(VSSerialize serialize,
                                        ObjectOutputStream objectOutputStream)
     throws IOException {
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
+
         objectOutputStream.writeObject(booleanPrefs);
         objectOutputStream.writeObject(colorPrefs);
+        objectOutputStream.writeObject(descriptionPrefs);
         objectOutputStream.writeObject(floatPrefs);
         objectOutputStream.writeObject(integerPrefs);
-        objectOutputStream.writeObject(vectorPrefs);
         objectOutputStream.writeObject(longPrefs);
         objectOutputStream.writeObject(stringPrefs);
         objectOutputStream.writeObject(units);
+        objectOutputStream.writeObject(vectorPrefs);
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
     }
 
     /* (non-Javadoc)
@@ -962,18 +969,26 @@ public class VSPrefs implements VSSerializable {
     public synchronized void deserialize(VSSerialize serialize,
                                          ObjectInputStream objectInputStream)
     throws IOException, ClassNotFoundException {
+        objectPrefs.clear();
+
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
         booleanPrefs = (HashMap<String,Boolean>) objectInputStream.readObject();
         colorPrefs = (HashMap<String,Color>) objectInputStream.readObject();
-        descriptionPrefs = new HashMap<String,String>();
+        descriptionPrefs = (HashMap<String,String>)
+                           objectInputStream.readObject();
         floatPrefs = (HashMap<String,Float>) objectInputStream.readObject();
         integerPrefs = (HashMap<String,Integer>) objectInputStream.readObject();
-        vectorPrefs = (HashMap<String,Vector<Integer>>)
-                      objectInputStream.readObject();
         longPrefs = (HashMap<String,Long>) objectInputStream.readObject();
         restrictions = new HashMap<String,VSPrefsRestriction>();
         stringPrefs = (HashMap<String,String>) objectInputStream.readObject();
         units = (HashMap<String,String>) objectInputStream.readObject();
-        objectPrefs.clear();
+        vectorPrefs = (HashMap<String,Vector<Integer>>)
+                      objectInputStream.readObject();
+
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
     }
 
     /**
diff --git a/sources/protocols/VSAbstractProtocol.java b/sources/protocols/VSAbstractProtocol.java
index 9999f62..39d338a 100644
--- a/sources/protocols/VSAbstractProtocol.java
+++ b/sources/protocols/VSAbstractProtocol.java
@@ -111,15 +111,15 @@ abstract public class VSAbstractProtocol extends VSAbstractEvent {
         if (hasOnServerStart) {
             if (isServer) {
                 currentContextIsServer(true);
-				if (!isServerInitialized)
-					onInit();
+                if (!isServerInitialized)
+                    onInit();
                 onServerStart();
             }
         } else {
             if (isClient) {
                 currentContextIsServer(false);
-				if (!isClientInitialized)
-					onInit();
+                if (!isClientInitialized)
+                    onInit();
                 onClientStart();
             }
         }
@@ -132,13 +132,13 @@ abstract public class VSAbstractProtocol extends VSAbstractEvent {
         if (isClient) {
             currentContextIsServer(false);
             onClientInit();
-			isClientInitialized = true;
+            isClientInitialized = true;
         }
 
         if (isServer) {
             currentContextIsServer(true);
             onServerInit();
-			isServerInitialized = true;
+            isServerInitialized = true;
         }
     }
 
@@ -173,15 +173,15 @@ abstract public class VSAbstractProtocol extends VSAbstractEvent {
 
         if (isServer) {
             currentContextIsServer(true);
-			if (!isServerInitialized)
-				onInit();
+            if (!isServerInitialized)
+                onInit();
             onServerRecv(message);
         }
 
         if (isClient) {
             currentContextIsServer(false);
-			if (!isClientInitialized)
-				onInit();
+            if (!isClientInitialized)
+                onInit();
             onClientRecv(message);
         }
     }
@@ -408,7 +408,14 @@ abstract public class VSAbstractProtocol extends VSAbstractEvent {
                                        ObjectOutputStream objectOutputStream)
     throws IOException {
         super.serialize(serialize, objectOutputStream);
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
+
         objectOutputStream.writeObject(new Boolean(hasOnServerStart));
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
     }
 
     /* (non-Javadoc)
@@ -424,7 +431,13 @@ abstract public class VSAbstractProtocol extends VSAbstractEvent {
         if (VSSerialize.DEBUG)
             System.out.println("Deserializing: VSAbstractProtocol");
 
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
         this.hasOnServerStart = ((Boolean)
                                  objectInputStream.readObject()).booleanValue();
+
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
     }
 }
diff --git a/sources/serialize/VSSerialize.java b/sources/serialize/VSSerialize.java
index 7591ea1..0d44d31 100644
--- a/sources/serialize/VSSerialize.java
+++ b/sources/serialize/VSSerialize.java
@@ -159,12 +159,12 @@ public final class VSSerialize {
      * @param simulator The simulator
      */
     public void saveSimulator(String filename, VSSimulator simulator) {
-		if (filename == null) {
-			saveSimulator(simulator);
-			return;
-		}
+        if (filename == null) {
+            saveSimulator(simulator);
+            return;
+        }
 
-		LAST_FILENAME = filename;
+        LAST_FILENAME = filename;
 
         try {
             FileOutputStream fileOutputStream =
@@ -177,7 +177,7 @@ public final class VSSerialize {
             simulator.serialize(this, objectOutputStream);
 
         } catch (IOException e) {
-            e.printStackTrace();
+            //e.printStackTrace();
 
         } finally {
             //objectOutputStream.close();
@@ -190,17 +190,17 @@ public final class VSSerialize {
      * @param simulator The simulator
      */
     public void saveSimulator(VSSimulator simulator) {
-		VSPrefs prefs = simulator.getPrefs();
-		VSSimulatorFrame simulatorFrame = simulator.getSimulatorFrame();
+        VSPrefs prefs = simulator.getPrefs();
+        VSSimulatorFrame simulatorFrame = simulator.getSimulatorFrame();
 
-		JFileChooser fileChooser = new JFileChooser();
-		fileChooser.setMultiSelectionEnabled(false);
-		fileChooser.addChoosableFileFilter(createFileFilter(prefs));
+        JFileChooser fileChooser = new JFileChooser();
+        fileChooser.setMultiSelectionEnabled(false);
+        fileChooser.addChoosableFileFilter(createFileFilter(prefs));
 
-		if (fileChooser.showOpenDialog(simulatorFrame) ==
-				JFileChooser.APPROVE_OPTION) 
-			saveSimulator(fileChooser.getSelectedFile().getName(), 
-					simulator);
+        if (fileChooser.showOpenDialog(simulatorFrame) ==
+                JFileChooser.APPROVE_OPTION)
+            saveSimulator(fileChooser.getSelectedFile().getName(),
+                          simulator);
     }
 
     /**
@@ -230,7 +230,7 @@ public final class VSSerialize {
             simulator.deserialize(this, objectInputStream);
 
         } catch (Exception e) {
-            e.printStackTrace();
+            //e.printStackTrace();
 
         } finally {
             //objectInputStream.close();
@@ -247,38 +247,38 @@ public final class VSSerialize {
      * @return The simulator object, and null if no success
      */
     public VSSimulator openSimulator(VSSimulatorFrame simulatorFrame) {
-		VSPrefs prefs = simulatorFrame.getPrefs();
+        VSPrefs prefs = simulatorFrame.getPrefs();
 
-		JFileChooser fileChooser = new JFileChooser();
-		fileChooser.setMultiSelectionEnabled(false);
-		fileChooser.addChoosableFileFilter(createFileFilter(prefs));
+        JFileChooser fileChooser = new JFileChooser();
+        fileChooser.setMultiSelectionEnabled(false);
+        fileChooser.addChoosableFileFilter(createFileFilter(prefs));
 
-		if (fileChooser.showOpenDialog(simulatorFrame) ==
-				JFileChooser.APPROVE_OPTION) 
-			return openSimulator(fileChooser.getSelectedFile().getName(),
-					simulatorFrame);
+        if (fileChooser.showOpenDialog(simulatorFrame) ==
+                JFileChooser.APPROVE_OPTION)
+            return openSimulator(fileChooser.getSelectedFile().getName(),
+                                 simulatorFrame);
 
         return null;
     }
 
     /**
      * Creates a file filter for the file choosers
-	 *
-	 * @param prefs The default prefs
+     *
+     * @param prefs The default prefs
      */
     private javax.swing.filechooser.FileFilter createFileFilter(
-			final VSPrefs prefs) {
-		return new javax.swing.filechooser.FileFilter() {
-			public boolean accept(File file) {
-				if (file.isDirectory())
-					return true;
-				return file.getName().toLowerCase().endsWith(".dat");
-			}
-
-			public String getDescription() {
-				return prefs.getString("lang.dat");
-			}
-		};
+        final VSPrefs prefs) {
+        return new javax.swing.filechooser.FileFilter() {
+            public boolean accept(File file) {
+                if (file.isDirectory())
+                    return true;
+                return file.getName().toLowerCase().endsWith(".dat");
+            }
+
+            public String getDescription() {
+                return prefs.getString("lang.dat");
+            }
+        };
     }
 
 }
diff --git a/sources/simulator/VSSimulator.java b/sources/simulator/VSSimulator.java
index aec330e..0a7c6c2 100644
--- a/sources/simulator/VSSimulator.java
+++ b/sources/simulator/VSSimulator.java
@@ -1232,7 +1232,14 @@ public class VSSimulator extends JPanel implements VSSerializable {
     public synchronized void serialize(VSSerialize serialize,
                                        ObjectOutputStream objectOutputStream)
     throws IOException {
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
+
         simulatorCanvas.serialize(serialize, objectOutputStream);
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
+
     }
 
     /* (non-Javadoc)
@@ -1248,8 +1255,15 @@ public class VSSimulator extends JPanel implements VSSerializable {
 
         serialize.setObject("simulator", this);
         serialize.setObject("logging", logging);
+
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
         simulatorCanvas.deserialize(serialize, objectInputStream);
 
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
         updateFromPrefs();
         updateTaskManagerTable();
     }
diff --git a/sources/simulator/VSSimulatorCanvas.java b/sources/simulator/VSSimulatorCanvas.java
index 1b30a51..b521fc7 100644
--- a/sources/simulator/VSSimulatorCanvas.java
+++ b/sources/simulator/VSSimulatorCanvas.java
@@ -1571,6 +1571,9 @@ public class VSSimulatorCanvas extends Canvas
     public synchronized void serialize(VSSerialize serialize,
                                        ObjectOutputStream objectOutputStream)
     throws IOException {
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
+
         synchronized (processes) {
             objectOutputStream.writeObject(new Integer(numProcesses));
             for (VSProcess process : processes)
@@ -1578,6 +1581,9 @@ public class VSSimulatorCanvas extends Canvas
         }
 
         taskManager.serialize(serialize, objectOutputStream);
+
+        /** For later backwards compatibility, to add more stuff */
+        objectOutputStream.writeObject(new Boolean(false));
     }
 
     /* (non-Javadoc)
@@ -1591,6 +1597,9 @@ public class VSSimulatorCanvas extends Canvas
         if (VSSerialize.DEBUG)
             System.out.println("Deserializing: VSSimulatorCanvas");
 
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
+
         int num = ((Integer) objectInputStream.readObject()).intValue();
         logging.clear();
 
@@ -1604,8 +1613,11 @@ public class VSSimulatorCanvas extends Canvas
         }
 
         for (int i = 0; i < num; ++i)
-            processes.get(0).deserialize(serialize, objectInputStream);
+            processes.get(i).deserialize(serialize, objectInputStream);
 
         taskManager.deserialize(serialize, objectInputStream);
+
+        /** For later backwards compatibility, to add more stuff */
+        objectInputStream.readObject();
     }
 }
diff --git a/sources/simulator/VSSimulatorFrame.java b/sources/simulator/VSSimulatorFrame.java
index 2b9042c..ad095c4 100644
--- a/sources/simulator/VSSimulatorFrame.java
+++ b/sources/simulator/VSSimulatorFrame.java
@@ -149,8 +149,8 @@ public class VSSimulatorFrame extends VSFrame {
                     VSSerialize serialize = new VSSerialize();
                     VSSimulator simulator = serialize.openSimulator(
                                                 VSSimulatorFrame.this);
-					if (simulator != null)
-                    	addSimulator(simulator);
+                    if (simulator != null)
+                        addSimulator(simulator);
 
                 } else if (sourceText.equals(
                 finalPrefs.getString("lang.save"))) {