Revamped location and cluster handling so that we can implement the fancy

new dynamic cluster system all good and proper.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@2330 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/whirled/spot/client/SpotSceneDirector.java

@@ -1,5 +1,5 @@
 //
-// $Id: SpotSceneDirector.java,v 1.22 2003/03/25 19:28:58 mdb Exp $
+// $Id: SpotSceneDirector.java,v 1.23 2003/03/26 02:06:06 mdb Exp $
 
 package com.threerings.whirled.spot.client;
 
@@ -9,6 +9,7 @@ import com.samskivert.util.StringUtil;
 
 import com.threerings.presents.client.BasicDirector;
 import com.threerings.presents.client.Client;
+import com.threerings.presents.client.InvocationService.ConfirmListener;
 import com.threerings.presents.dobj.AttributeChangeListener;
 import com.threerings.presents.dobj.AttributeChangedEvent;
 
@@ -39,27 +40,8 @@ import com.threerings.whirled.spot.data.SpotScene;
  * locations within a scene.
  */
 public class SpotSceneDirector extends BasicDirector
-    implements SpotCodes, Subscriber, SpotService.ChangeLocListener,
+    implements SpotCodes, Subscriber, AttributeChangeListener
-               AttributeChangeListener
 {
-    /**
-     * This is used to communicate back to the caller of {@link
-     * #changeLocation}.
-     */
-    public static interface ChangeObserver
-    {
-        /**
-         * Indicates that the requested location change succeeded.
-         */
-        public void locationChangeSucceeded (Location loc);
-
-        /**
-         * Indicates that the requested location change failed and
-         * provides a reason code explaining the failure.
-         */
-        public void locationChangeFailed (Location loc, String reason);
-    }
-
     /**
      * Creates a new spot scene director with the specified context and
      * which will cooperate with the supplied scene director.
@@ -155,16 +137,9 @@ public class SpotSceneDirector extends BasicDirector
 
     /**
      * Issues a request to change our location within the scene to the
-     * specified location. Depending on the value of <code>cluster</code>
+     * specified location.
-     * the client will be made to create a new cluster, join and existing
-     * cluster or join no cluster at all.
      *
      * @param loc the new location to which to move.
-     * @param cluster if zero, a new cluster will be created and assigned
-     * to the calling user; if -1, the calling user will be removed from
-     * any cluster they currently occupy and not made to occupy a new
-     * cluster; if the bodyOid of another user, the calling user will be
-     * made to join the target user's cluster.
      * @param obs will be notified of success or failure. Most client
      * entities find out about location changes via changes to the
      * occupant info data, but the initiator of a location change request
@@ -173,7 +148,7 @@ public class SpotSceneDirector extends BasicDirector
      * starting a sprite moving toward the new location), but backtrack if
      * it finds out that the location change failed.
      */
-    public void changeLocation (Location loc, int cluster, ChangeObserver obs)
+    public void changeLocation (Location loc, final ResultListener listener)
     {
         // refuse if there's a pending location change or if we're already
         // at the specified location
@@ -190,11 +165,59 @@ public class SpotSceneDirector extends BasicDirector
             return;
         }
 
-        Log.info("Changing location [loc=" + loc + ", clus=" + cluster + "].");
+        Log.info("Changing location [loc=" + loc + "].");
 
         _pendingLoc = (Location)loc.clone();
-        _changeObserver = obs;
+        _sservice.changeLocation(_ctx.getClient(), loc, new ConfirmListener() {
-        _sservice.changeLoc(_ctx.getClient(), loc, cluster, this);
+            public void requestProcessed () {
+                _location = _pendingLoc;
+                _pendingLoc = null;
+                if (listener != null) {
+                    listener.requestCompleted(_location);
+                }
+            }
+
+            public void requestFailed (String reason) {
+                _pendingLoc = null;
+                if (listener != null) {
+                    listener.requestFailed(new Exception(reason));
+                }
+            }
+        });
+    }
+
+    /**
+     * Issues a request to join the cluster associated with the specified
+     * user (starting one if necessary).
+     *
+     * @param froid the bodyOid of another user; the calling user will
+     * be made to join the target user's cluster.
+     * @param listener will be notified of success or failure.
+     */
+    public void joinCluster (int froid, final ResultListener listener)
+    {
+        SpotScene scene = (SpotScene)_scdir.getScene();
+        if (scene == null) {
+            Log.warning("Requested to join cluster, but we're not " +
+                        "currently in any scene [froid=" + froid + "].");
+            return;
+        }
+
+        Log.info("Joining cluster [friend=" + froid + "].");
+
+        _sservice.joinCluster(_ctx.getClient(), froid, new ConfirmListener() {
+            public void requestProcessed () {
+                if (listener != null) {
+                    listener.requestCompleted(null);
+                }
+            }
+
+            public void requestFailed (String reason) {
+                if (listener != null) {
+                    listener.requestFailed(new Exception(reason));
+                }
+            }
+        });
     }
 
     /**
@@ -237,38 +260,6 @@ public class SpotSceneDirector extends BasicDirector
         return true;
     }
 
-    // documentation inherited from interface
-    public void changeLocSucceeded ()
-    {
-        ChangeObserver obs = _changeObserver;
-        _location = _pendingLoc;
-
-        // clear out our pending location info
-        _pendingLoc = null;
-        _changeObserver = null;
-
-        // if we had an observer, let them know things went well
-        if (obs != null) {
-            obs.locationChangeSucceeded(_location);
-        }
-    }
-
-    // documentation inherited from interface
-    public void requestFailed (String reason)
-    {
-        ChangeObserver obs = _changeObserver;
-        Location loc = _pendingLoc;
-
-        // clear out our pending location info
-        _pendingLoc = null;
-        _changeObserver = null;
-
-        // if we had an observer, let them know things went well
-        if (obs != null) {
-            obs.locationChangeFailed(loc, reason);
-        }
-    }
-
     // documentation inherited
     public void objectAvailable (DObject object)
     {
@@ -336,7 +327,6 @@ public class SpotSceneDirector extends BasicDirector
         // clear out our business
         _location = null;
         _pendingLoc = null;
-        _changeObserver = null;
         _sservice = null;
         clearCluster();
 
@@ -403,8 +393,4 @@ public class SpotSceneDirector extends BasicDirector
 
     /** The cluster chat object for the cluster we currently occupy. */
     protected DObject _clobj;
-
-    /** An entity that wants to know if a requested location change
-     * succeeded or failed. */
-    protected ChangeObserver _changeObserver;
 }

src/java/com/threerings/whirled/spot/client/SpotService.java

@@ -1,5 +1,5 @@
 //
-// $Id: SpotService.java,v 1.13 2003/02/13 21:55:22 mdb Exp $
+// $Id: SpotService.java,v 1.14 2003/03/26 02:06:06 mdb Exp $
 
 package com.threerings.whirled.spot.client;
 
@@ -28,30 +28,26 @@ public interface SpotService extends InvocationService
         Client client, int portalId, int destSceneVer,
         SceneMoveListener listener);
 
-    /**
-     * Used to communicate responses to a {@link #changeLoc} request.
-     */
-    public static interface ChangeLocListener extends InvocationListener
-    {
-        /**
-         * Called when the change location request succeeds.
-         */
-        public void changeLocSucceeded ();
-    }
-
     /**
      * Requests that this client's body be made to move to the specified
-     * location.
+     * location. The user will be removed from any cluster from which they
+     * are an occupant.
      *
      * @param loc the location to which to move.
-     * @param cluster if -1, the calling user will be removed from any
-     * cluster they currently occupy and not made to occupy a new cluster;
-     * if the bodyOid of another user, the calling user will be made to
-     * join the target user's cluster, or create a cluster with the target
-     * user if they are not already in one.
      */
-    public void changeLoc (Client client, Location loc, int cluster,
+    public void changeLocation (Client client, Location loc,
-                           ChangeLocListener listener);
+                                ConfirmListener listener);
+
+    /**
+     * Requests that this client start or join the specified cluster. They
+     * will be relocated appropriately by the scene manager.
+     *
+     * @param friendOid the bodyOid of another user; the calling user will
+     * be made to join the target user's cluster, or create a cluster with
+     * the target user if they are not already in one.
+     */
+    public void joinCluster (Client client, int friendOid,
+                             ConfirmListener listener);
 
     /**
      * Requests that the supplied message be delivered to listeners in the

src/java/com/threerings/whirled/spot/data/SpotMarshaller.java

@@ -1,15 +1,15 @@
 //
-// $Id: SpotMarshaller.java,v 1.3 2003/02/12 07:23:31 mdb Exp $
+// $Id: SpotMarshaller.java,v 1.4 2003/03/26 02:06:06 mdb Exp $
 
 package com.threerings.whirled.spot.data;
 
 import com.threerings.presents.client.Client;
+import com.threerings.presents.client.InvocationService.ConfirmListener;
 import com.threerings.presents.data.InvocationMarshaller;
 import com.threerings.presents.dobj.InvocationResponseEvent;
 import com.threerings.whirled.client.SceneService.SceneMoveListener;
 import com.threerings.whirled.data.SceneMarshaller.SceneMoveMarshaller;
 import com.threerings.whirled.spot.client.SpotService;
-import com.threerings.whirled.spot.client.SpotService.ChangeLocListener;
 import com.threerings.whirled.spot.data.Location;
 
 /**
@@ -22,37 +22,6 @@ import com.threerings.whirled.spot.data.Location;
 public class SpotMarshaller extends InvocationMarshaller
     implements SpotService
 {
-    // documentation inherited
-    public static class ChangeLocMarshaller extends ListenerMarshaller
-        implements ChangeLocListener
-    {
-        /** The method id used to dispatch {@link #changeLocSucceeded}
-         * responses. */
-        public static final int CHANGE_LOC_SUCCEEDED = 1;
-
-        // documentation inherited from interface
-        public void changeLocSucceeded ()
-        {
-            omgr.postEvent(new InvocationResponseEvent(
-                               callerOid, requestId, CHANGE_LOC_SUCCEEDED,
-                               new Object[] {  }));
-        }
-
-        // documentation inherited
-        public void dispatchResponse (int methodId, Object[] args)
-        {
-            switch (methodId) {
-            case CHANGE_LOC_SUCCEEDED:
-                ((ChangeLocListener)listener).changeLocSucceeded(
-                    );
-                return;
-
-            default:
-                super.dispatchResponse(methodId, args);
-            }
-        }
-    }
-
     /** The method id used to dispatch {@link #traversePortal} requests. */
     public static final int TRAVERSE_PORTAL = 1;
 
@@ -66,21 +35,34 @@ public class SpotMarshaller extends InvocationMarshaller
         });
     }
 
-    /** The method id used to dispatch {@link #changeLoc} requests. */
+    /** The method id used to dispatch {@link #changeLocation} requests. */
-    public static final int CHANGE_LOC = 2;
+    public static final int CHANGE_LOCATION = 2;
 
     // documentation inherited from interface
-    public void changeLoc (Client arg1, Location arg2, int arg3, ChangeLocListener arg4)
+    public void changeLocation (Client arg1, Location arg2, ConfirmListener arg3)
     {
-        ChangeLocMarshaller listener4 = new ChangeLocMarshaller();
+        ConfirmMarshaller listener3 = new ConfirmMarshaller();
-        listener4.listener = arg4;
+        listener3.listener = arg3;
-        sendRequest(arg1, CHANGE_LOC, new Object[] {
+        sendRequest(arg1, CHANGE_LOCATION, new Object[] {
-            arg2, new Integer(arg3), listener4
+            arg2, listener3
+        });
+    }
+
+    /** The method id used to dispatch {@link #joinCluster} requests. */
+    public static final int JOIN_CLUSTER = 3;
+
+    // documentation inherited from interface
+    public void joinCluster (Client arg1, int arg2, ConfirmListener arg3)
+    {
+        ConfirmMarshaller listener3 = new ConfirmMarshaller();
+        listener3.listener = arg3;
+        sendRequest(arg1, JOIN_CLUSTER, new Object[] {
+            new Integer(arg2), listener3
         });
     }
 
     /** The method id used to dispatch {@link #clusterSpeak} requests. */
-    public static final int CLUSTER_SPEAK = 3;
+    public static final int CLUSTER_SPEAK = 4;
 
     // documentation inherited from interface
     public void clusterSpeak (Client arg1, String arg2, byte arg3)
@@ -90,5 +72,4 @@ public class SpotMarshaller extends InvocationMarshaller
         });
     }
 
-    // Generated on 10:09:04 02/05/03.
 }

src/java/com/threerings/whirled/spot/server/SpotDispatcher.java

@@ -1,9 +1,10 @@
 //
-// $Id: SpotDispatcher.java,v 1.3 2003/02/12 07:23:31 mdb Exp $
+// $Id: SpotDispatcher.java,v 1.4 2003/03/26 02:06:06 mdb Exp $
 
 package com.threerings.whirled.spot.server;
 
 import com.threerings.presents.client.Client;
+import com.threerings.presents.client.InvocationService.ConfirmListener;
 import com.threerings.presents.data.ClientObject;
 import com.threerings.presents.data.InvocationMarshaller;
 import com.threerings.presents.server.InvocationDispatcher;
@@ -11,7 +12,6 @@ import com.threerings.presents.server.InvocationException;
 import com.threerings.whirled.client.SceneService.SceneMoveListener;
 import com.threerings.whirled.data.SceneMarshaller.SceneMoveMarshaller;
 import com.threerings.whirled.spot.client.SpotService;
-import com.threerings.whirled.spot.client.SpotService.ChangeLocListener;
 import com.threerings.whirled.spot.data.Location;
 import com.threerings.whirled.spot.data.SpotMarshaller;
 
@@ -48,10 +48,17 @@ public class SpotDispatcher extends InvocationDispatcher
             );
             return;
 
-        case SpotMarshaller.CHANGE_LOC:
+        case SpotMarshaller.CHANGE_LOCATION:
-            ((SpotProvider)provider).changeLoc(
+            ((SpotProvider)provider).changeLocation(
                 source,
-                (Location)args[0], ((Integer)args[1]).intValue(), (ChangeLocListener)args[2]
+                (Location)args[0], (ConfirmListener)args[1]
+            );
+            return;
+
+        case SpotMarshaller.JOIN_CLUSTER:
+            ((SpotProvider)provider).joinCluster(
+                source,
+                ((Integer)args[0]).intValue(), (ConfirmListener)args[1]
             );
             return;
 
@@ -66,6 +73,4 @@ public class SpotDispatcher extends InvocationDispatcher
             super.dispatchRequest(source, methodId, args);
         }
     }
-
-    // Generated on 10:09:04 02/05/03.
 }

src/java/com/threerings/whirled/spot/server/SpotProvider.java

@@ -1,5 +1,5 @@
 //
-// $Id: SpotProvider.java,v 1.16 2003/03/17 19:34:26 mdb Exp $
+// $Id: SpotProvider.java,v 1.17 2003/03/26 02:06:06 mdb Exp $
 
 package com.threerings.whirled.spot.server;
 
@@ -23,7 +23,7 @@ import com.threerings.whirled.server.SceneManager;
 import com.threerings.whirled.server.SceneRegistry;
 
 import com.threerings.whirled.spot.Log;
-import com.threerings.whirled.spot.client.SpotService.ChangeLocListener;
+import com.threerings.whirled.spot.client.SpotService;
 import com.threerings.whirled.spot.data.Location;
 import com.threerings.whirled.spot.data.Portal;
 import com.threerings.whirled.spot.data.SpotCodes;
@@ -137,10 +137,10 @@ public class SpotProvider
     }
 
     /**
-     * Processes a {@link SpotService#changeLog} request.
+     * Processes a {@link SpotService#changeLocation} request.
      */
-    public void changeLoc (ClientObject caller, Location loc, int cluster,
+    public void changeLocation (ClientObject caller, Location loc,
-                           ChangeLocListener listener)
+                                SpotService.ConfirmListener listener)
         throws InvocationException
     {
         int sceneId = getCallerSceneId(caller);
@@ -150,17 +150,44 @@ public class SpotProvider
         SpotSceneManager smgr = (SpotSceneManager)
             _screg.getSceneManager(sceneId);
         if (smgr == null) {
-            Log.warning("User requested to change location in " +
+            Log.warning("User requested to change location from " +
                         "non-existent scene [user=" + source.who() +
                         ", sceneId=" + sceneId + ", loc=" + loc +"].");
             throw new InvocationException(INTERNAL_ERROR);
         }
 
         // pass the buck to yon scene manager
-        smgr.handleChangeLocRequest(source, loc, cluster);
+        smgr.handleChangeLoc(source, loc);
 
         // if that method finished, we're good to go
-        listener.changeLocSucceeded();
+        listener.requestProcessed();
+    }
+
+    /**
+     * Processes a {@link SpotService#joinCluster} request.
+     */
+    public void joinCluster (ClientObject caller, int friendOid,
+                             SpotService.ConfirmListener listener)
+        throws InvocationException
+    {
+        int sceneId = getCallerSceneId(caller);
+        BodyObject source = (BodyObject)caller;
+
+        // look up the scene manager for the specified scene
+        SpotSceneManager smgr = (SpotSceneManager)
+            _screg.getSceneManager(sceneId);
+        if (smgr == null) {
+            Log.warning("User requested to join cluster from " +
+                        "non-existent scene [user=" + source.who() +
+                        ", sceneId=" + sceneId + ", foid=" + friendOid +"].");
+            throw new InvocationException(INTERNAL_ERROR);
+        }
+
+        // pass the buck to yon scene manager
+        smgr.handleJoinCluster(source, friendOid);
+
+        // if that method finished, we're good to go
+        listener.requestProcessed();
     }
 
     /**

src/java/com/threerings/whirled/spot/server/SpotSceneManager.java

@@ -1,5 +1,5 @@
 //
-// $Id: SpotSceneManager.java,v 1.29 2003/03/25 19:28:59 mdb Exp $
+// $Id: SpotSceneManager.java,v 1.30 2003/03/26 02:06:06 mdb Exp $
 
 package com.threerings.whirled.spot.server;
 
@@ -53,7 +53,7 @@ public class SpotSceneManager extends SceneManager
             SpotScene scene = (SpotScene)mgr.getScene();
             try {
                 Location eloc = scene.getDefaultEntrance().getLocation();
-                mgr.handleChangeLocRequest(body, eloc, -1);
+                mgr.handleChangeLoc(body, eloc);
             } catch (InvocationException ie) {
                 Log.warning("Could not move user to default portal " +
                             "[where=" + mgr.where() + ", who=" + body.who() +
@@ -170,11 +170,9 @@ public class SpotSceneManager extends SceneManager
      * join the other user's cluster.
      *
      * @exception InvocationException thrown with a reason code explaining
-     * the location change failure if there is a problem processing the
+     * the failure if there is a problem processing the request.
-     * location change request.
      */
-    protected void handleChangeLocRequest (
+    protected void handleChangeLoc (BodyObject source, Location loc)
-        BodyObject source, Location loc, int cluster)
         throws InvocationException
     {
         // make sure they are in our scene
@@ -201,13 +199,50 @@ public class SpotSceneManager extends SceneManager
             _ssobj.updateOccupantLocs(sloc);
         }
 
-        // handle the cluster situation; -1 means remove, our own oid
+        // remove them from any cluster as they've departed
-        // means leave us in whatever cluster we're already in; someone
+        removeFromCluster(source.getOid());
-        // else's oid means join their cluster or start one with them
+    }
-        if (cluster == -1) {
+
-            removeFromCluster(source.getOid());
+    /**
-        } else if (cluster != source.getOid()) {
+     * Called by the {@link SpotProvider} when we receive a request by a
-            createOrJoinCluster(cluster, source);
+     * user to join a particular cluster.
+     *
+     * @param joiner the body to be moved.
+     * @param friendOid the bodyOid of another user; the moving user will
+     * be made to join the other user's cluster.
+     *
+     * @exception InvocationException thrown with a reason code explaining
+     * the failure if there is a problem processing the request.
+     */
+    protected void handleJoinCluster (BodyObject joiner, int friendOid)
+        throws InvocationException
+    {
+        ClusterRecord clrec = (ClusterRecord)_clusters.get(friendOid);
+        if (clrec != null) {
+            // if the cluster already exists, add this user and be done
+            if (clrec.addBody(joiner)) {
+                _clusters.put(joiner.getOid(), clrec);
+            }
+            return;
+        }
+
+        // otherwise we have to create a new cluster and add our two
+        // charter members!
+        clrec = new ClusterRecord();
+        BodyObject member = (BodyObject)CrowdServer.omgr.getObject(friendOid);
+        if (member == null) {
+            Log.warning("Can't create cluster, missing target " +
+                        "[creator=" + joiner.who() +
+                        ", friendOid=" + friendOid + "].");
+            return;
+        }
+
+        // add our two lovely users to the newly created cluster
+        if (clrec.addBody(joiner)) {
+            _clusters.put(joiner.getOid(), clrec);
+        }
+        if (clrec.addBody(member)) {
+            _clusters.put(member.getOid(), clrec);
         }
     }
 
@@ -229,42 +264,6 @@ public class SpotSceneManager extends SceneManager
         // quietly off itself when it's done subscribing to its object
     }
 
-    /**
-     * Adds the specified user to the cluster occupied by the specified
-     * other user or creates a new cluster for the two users if neither is
-     * already clustered.
-     */
-    protected void createOrJoinCluster (int memberOid, BodyObject joiner)
-    {
-        ClusterRecord clrec = (ClusterRecord)_clusters.get(memberOid);
-        if (clrec != null) {
-            // if the cluster already exists, add this user and be done
-            if (clrec.addBody(joiner)) {
-                _clusters.put(joiner.getOid(), clrec);
-            }
-            return;
-        }
-
-        // otherwise we have to create a new cluster and add our two
-        // charter members!
-        clrec = new ClusterRecord();
-        BodyObject member = (BodyObject)CrowdServer.omgr.getObject(memberOid);
-        if (member == null) {
-            Log.warning("Can't create cluster, missing target " +
-                        "[creator=" + joiner.who() +
-                        ", targetOid=" + memberOid + "].");
-            return;
-        }
-
-        // add our two lovely users to the newly created cluster
-        if (clrec.addBody(joiner)) {
-            _clusters.put(joiner.getOid(), clrec);
-        }
-        if (clrec.addBody(member)) {
-            _clusters.put(member.getOid(), clrec);
-        }
-    }
-
     /**
      * Removes the specified user from any cluster they occupy.
      */
@@ -322,6 +321,24 @@ public class SpotSceneManager extends SceneManager
         loc.y = cy;
     }
 
+    /**
+     * Called when a user is added to a cluster. The scene manager
+     * implementation should take this opportunity to rearrange everyone
+     * in the cluster appropriately for the new size.
+     */
+    protected void bodyAdded (ClusterRecord clrec, BodyObject body)
+    {
+    }
+
+    /**
+     * Called when a user is removed from a cluster. The scene manager
+     * implementation should take this opportunity to rearrange everyone
+     * in the cluster appropriately for the new size.
+     */
+    protected void bodyRemoved (ClusterRecord clrec, BodyObject body)
+    {
+    }
+
     /**
      * Used to manage clusters which are groups of users that can chat to
      * one another.
@@ -344,11 +361,21 @@ public class SpotSceneManager extends SceneManager
 
                 put(body.getOid(), body);
                 _cluster.occupants++;
-                recomputeCenter();
+                try {
-                if (_clobj != null) {
+                    body.startTransaction();
-                    ((ClusteredBodyObject)body).setClusterOid(_clobj.getOid());
+                    _ssobj.startTransaction();
-                    _clobj.addToOccupants(body.getOid());
+                    bodyAdded(this, body); // do the hokey pokey
-                    _ssobj.updateClusters(_cluster);
+
+                    if (_clobj != null) {
+                        ((ClusteredBodyObject)body).setClusterOid(
+                            _clobj.getOid());
+                        _clobj.addToOccupants(body.getOid());
+                        _ssobj.updateClusters(_cluster);
+                    }
+
+                } finally {
+                    _clobj.commitTransaction();
+                    _ssobj.commitTransaction();
                 }
 
                 Log.info("Added " + body.who() + " to "+ this + ".");
@@ -364,7 +391,7 @@ public class SpotSceneManager extends SceneManager
 
         public void removeBody (int bodyOid)
         {
-            ClusteredBodyObject body = (ClusteredBodyObject)remove(bodyOid);
+            BodyObject body = (BodyObject)remove(bodyOid);
             if (body == null) {
                 Log.warning("Requested to remove unknown body from cluster " +
                             "[cloid=" + _clobj.getOid() +
@@ -372,13 +399,23 @@ public class SpotSceneManager extends SceneManager
                 return;
             }
 
-            body.setClusterOid(-1);
+            try {
-            _cluster.occupants--;
+                body.startTransaction();
-            recomputeCenter();
+                _ssobj.startTransaction();
-            if (_clobj != null) {
+                ((ClusteredBodyObject)body).setClusterOid(-1);
-                _clobj.removeFromOccupants(bodyOid);
+                _cluster.occupants--;
-                _ssobj.updateClusters(_cluster);
+                bodyRemoved(this, body); // do the hokey pokey
+
+                if (_clobj != null) {
+                    _clobj.removeFromOccupants(bodyOid);
+                    _ssobj.updateClusters(_cluster);
+                }
+
+            } finally {
+                _ssobj.commitTransaction();
+                body.commitTransaction();
             }
+
             Log.info("Removed " + bodyOid + " from "+ this + ".");
 
             // if we've removed our last body; stick a fork in ourselves
@@ -392,6 +429,11 @@ public class SpotSceneManager extends SceneManager
             return _clobj;
         }
 
+        public Cluster getCluster ()
+        {
+            return _cluster;
+        }
+
         public void objectAvailable (DObject object)
         {
             // keep this feller around
@@ -434,31 +476,6 @@ public class SpotSceneManager extends SceneManager
             return "[cluster=" + _cluster + ", size=" + size() + "]";
         }
 
-        protected void recomputeCenter ()
-        {
-            int tx = 0, ty = 0, count = 0;
-
-            // compute the average x and y position of all our cluster
-            // occupants
-            Iterator iter = _ssobj.occupantLocs.entries();
-            while (iter.hasNext()) {
-                SceneLocation sloc = (SceneLocation)iter.next();
-                if (containsKey(sloc.bodyOid)) {
-                    locationToCoords(sloc.x, sloc.y, _scratch);
-                    tx += _scratch.x;
-                    ty += _scratch.x;
-                    count++;
-                }
-            }
-
-            if (count > 1) {
-                // convert the center back to "location" coordinates
-                coordsToLocation(tx/count, ty/count, _scratch);
-                _cluster.x = _scratch.x;
-                _cluster.y = _scratch.y;
-            }
-        }
-
         protected void destroy ()
         {
             Log.info("Cluster empty, going away " +
@@ -469,7 +486,6 @@ public class SpotSceneManager extends SceneManager
 
         protected ClusterObject _clobj;
         protected Cluster _cluster = new Cluster();
-        protected Point _scratch = new Point();
     }
 
     /** A casted reference to our place object. */