Wired up rest of location change stuff.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@776 542714f4-19e9-0310-aa3c-eee0fc999fb1

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

@@ -1,5 +1,5 @@
 //
-// $Id: SpotSceneDirector.java,v 1.1 2001/12/14 00:12:32 mdb Exp $
+// $Id: SpotSceneDirector.java,v 1.2 2001/12/14 01:51:46 mdb Exp $
 
 package com.threerings.whirled.spot.client;
 
@@ -22,6 +22,24 @@ import com.threerings.whirled.spot.data.Location;
 public class SpotSceneDirector extends SceneDirector
     implements SpotCodes
 {
+    /**
+     * 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 (int locationId);
+
+        /**
+         * Indicates that the requested location change failed and
+         * provides a reason code explaining the failure.
+         */
+        public void locationChangeFailed (int locationId, String reason);
+    }
+
     /**
      * Creates a new spot scene director with the specified context.
      *
@@ -39,9 +57,15 @@ public class SpotSceneDirector extends SceneDirector
 
     /**
      * Issues a request to change our location within the scene to the
-     * location identified by the specified id.
+     * location identified by the specified id. Most client entities find
+     * out about location changes via changes to the occupant info data,
+     * but the initiator of a location change request can be notified of
+     * its success or failure, primarily so that it can act in
+     * anticipation of a successful location change (like by starting a
+     * sprite moving toward the new location), but backtrack if it finds
+     * out that the location change failed.
      */
-    public void changeLocation (int locationId)
+    public void changeLocation (int locationId, ChangeObserver obs)
     {
         // refuse if there's a pending location change
         if (_pendingLocId != -1) {
@@ -76,6 +100,7 @@ public class SpotSceneDirector extends SceneDirector
 
         // make a note that we're changing to this location
         _pendingLocId = locationId;
+        _changeObserver = obs;
         // and send the location change request
         SpotService.changeLoc(_ctx.getClient(), _sceneId, locationId, this);
     }
@@ -85,6 +110,17 @@ public class SpotSceneDirector extends SceneDirector
      */
     public void handleChangeLocSucceeded (int invid)
     {
+        ChangeObserver obs = _changeObserver;
+        int locId = _pendingLocId;
+
+        // clear out our pending location info
+        _pendingLocId = -1;
+        _changeObserver = null;
+
+        // if we had an observer, let them know things went well
+        if (obs != null) {
+            obs.locationChangeSucceeded(locId);
+        }
     }
 
     /**
@@ -92,9 +128,24 @@ public class SpotSceneDirector extends SceneDirector
      */
     public void handleChangeLocFailed (int invid, String reason)
     {
+        ChangeObserver obs = _changeObserver;
+        int locId = _pendingLocId;
+
+        // clear out our pending location info
+        _pendingLocId = -1;
+        _changeObserver = null;
+
+        // if we had an observer, let them know things went well
+        if (obs != null) {
+            obs.locationChangeFailed(locId, reason);
+        }
     }
 
     /** The location id on which we have an outstanding change location
      * request. */
     protected int _pendingLocId = -1;
+
+    /** An entity that wants to know if a requested location change
+     * succeded or failed. */
+    protected ChangeObserver _changeObserver;
 }