From 54565c157ad98f039848804488f0c32ccb365d94 Mon Sep 17 00:00:00 2001
From: Michael Bayne <mdb@threerings.net>
Date: Mon, 17 Dec 2001 04:00:27 +0000
Subject: [PATCH] Created zone observers which are notified of successful or
 failed zone changes.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@823 542714f4-19e9-0310-aa3c-eee0fc999fb1
---
 .../whirled/zone/client/ZoneDirector.java     | 63 ++++++++++++++++++-
 .../whirled/zone/client/ZoneObserver.java     | 30 +++++++++
 2 files changed, 90 insertions(+), 3 deletions(-)
 create mode 100644 src/java/com/threerings/whirled/zone/client/ZoneObserver.java

diff --git a/src/java/com/threerings/whirled/zone/client/ZoneDirector.java b/src/java/com/threerings/whirled/zone/client/ZoneDirector.java
index 4a13595fc..18d84c92b 100644
--- a/src/java/com/threerings/whirled/zone/client/ZoneDirector.java
+++ b/src/java/com/threerings/whirled/zone/client/ZoneDirector.java
@@ -1,14 +1,17 @@
 //
-// $Id: ZoneDirector.java,v 1.2 2001/12/16 05:18:20 mdb Exp $
+// $Id: ZoneDirector.java,v 1.3 2001/12/17 04:00:27 mdb Exp $
 
 package com.threerings.whirled.zone.client;
 
+import java.util.ArrayList;
+
 import com.threerings.crowd.data.PlaceConfig;
 
 import com.threerings.whirled.client.SceneDirector;
 import com.threerings.whirled.data.SceneModel;
 import com.threerings.whirled.util.WhirledContext;
 
+import com.threerings.whirled.zone.Log;
 import com.threerings.whirled.zone.data.ZoneSummary;
 
 /**
@@ -44,6 +47,23 @@ public class ZoneDirector
         return _summary;
     }
 
+    /**
+     * Adds a zone observer to the list. This observer will subsequently
+     * be notified of effected and failed zone changes.
+     */
+    public void addZoneObserver (ZoneObserver observer)
+    {
+        _observers.add(observer);
+    }
+
+    /**
+     * Removes a zone observer from the list.
+     */
+    public void removeZoneObserver (ZoneObserver observer)
+    {
+        _observers.remove(observer);
+    }
+
     /**
      * Requests that this client move the specified scene in the specified
      * zone. A request will be made and when the response is received, the
@@ -87,8 +107,11 @@ public class ZoneDirector
         // keep track of the summary
         _summary = summary;
 
-        // and pass the rest off to the standard scene transition code
+        // pass the rest off to the standard scene transition code
         _scdir.handleMoveSucceeded(invid, placeId, config);
+
+        // and let the zone observers know what's up
+        notifyObservers(summary);
     }
 
     /**
@@ -103,8 +126,11 @@ public class ZoneDirector
         // keep track of the summary
         _summary = summary;
 
-        // and pass the rest off to the standard scene transition code
+        // pass the rest off to the standard scene transition code
         _scdir.handleMoveSucceededPlusUpdate(invid, placeId, config, model);
+
+        // and let the zone observers know what's up
+        notifyObservers(summary);
     }
 
     /**
@@ -112,7 +138,35 @@ public class ZoneDirector
      */
     public void handleMoveFailed (int invid, String reason)
     {
+        // let the scene director cope
         _scdir.handleMoveFailed(invid, reason);
+
+        // and let the observers know what's up
+        notifyObservers(reason);
+    }
+
+    /**
+     * Notifies observers of success or failure, depending on the type of
+     * object provided as data.
+     */
+    protected void notifyObservers (Object data)
+    {
+        // let our observers know that all is well on the western front
+        for (int i = 0; i < _observers.size(); i++) {
+            ZoneObserver obs = (ZoneObserver)_observers.get(i);
+            try {
+                if (data instanceof ZoneSummary) {
+                    obs.zoneDidChange((ZoneSummary)data);
+                } else {
+                    obs.zoneChangeFailed((String)data);
+                }
+
+            } catch (Throwable t) {
+                Log.warning("Zone observer choked during notification " +
+                            "[data=" + data + ", obs=" + obs + "].");
+                Log.logStackTrace(t);
+            }
+        }
     }
 
     /** A reference to the active client context. */
@@ -124,4 +178,7 @@ public class ZoneDirector
     /** A reference to the zone summary for the currently occupied
      * zone. */
     protected ZoneSummary _summary;
+
+    /** Our zone observer list. */
+    protected ArrayList _observers = new ArrayList();
 }
diff --git a/src/java/com/threerings/whirled/zone/client/ZoneObserver.java b/src/java/com/threerings/whirled/zone/client/ZoneObserver.java
new file mode 100644
index 000000000..5c070069e
--- /dev/null
+++ b/src/java/com/threerings/whirled/zone/client/ZoneObserver.java
@@ -0,0 +1,30 @@
+//
+// $Id: ZoneObserver.java,v 1.1 2001/12/17 04:00:27 mdb Exp $
+
+package com.threerings.whirled.zone.client;
+
+import com.threerings.whirled.zone.data.ZoneSummary;
+
+/**
+ * The zone observer interface makes it possible for entities to be
+ * notified when the client moves to a new zone.
+ */
+public interface ZoneObserver
+{
+    /**
+     * Called when we have switched to a new zone.
+     *
+     * @param summary the summary information for the new zone or null if
+     * we have switched to no zone.
+     */
+    public void zoneDidChange (ZoneSummary summary);
+
+    /**
+     * This is called on all zone observers when a zone change request is
+     * rejected by the server or fails for some other reason.
+     *
+     * @param reason the reason code that explains why the zone change
+     * request was rejected or otherwise failed.
+     */
+    public void zoneChangeFailed (String reason);
+}