Delegation! Since it's clear that extracting services into delegation

classes is only going to become more common, I've gone and created a
comprehensive facility for creating and using delegates in the place
controller and manager as well as the game controller and manager. With
the pattern nicely set, it is also easy to extend to controller/managers
further up the hierarchy that might need to delegate special methods of
their own. Whee!


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@994 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/crowd/server/PlaceManagerDelegate.java

@@ -0,0 +1,76 @@
+//
+// $Id: PlaceManagerDelegate.java,v 1.1 2002/02/13 03:21:28 mdb Exp $
+
+package com.threerings.crowd.server;
+
+import com.threerings.crowd.data.PlaceConfig;
+import com.threerings.crowd.data.PlaceObject;
+
+/**
+ * Provides an extensible mechanism for encapsulating delegated
+ * functionality that works with the place services.
+ *
+ * <p> Thanks to Java's lack of multiple inheritance, it will likely
+ * become necessary to factor certain services that might be used by a
+ * variety of {@link PlaceManager} derived classes into delegate classes
+ * because they do not fit into the single inheritance hierarchy that
+ * makes sense for a particular application. To facilitate this process,
+ * this delegate class is provided which the standard place manager can be
+ * made to call out to for all of the standard methods.
+ */
+public class PlaceManagerDelegate
+{
+    /**
+     * Provides the delegate with a reference to the manager for which it
+     * is delegating.
+     */
+    public PlaceManagerDelegate (PlaceManager plmgr)
+    {
+        _plmgr = plmgr;
+    }
+
+    /**
+     * Called when the place manager is initialized.
+     */
+    public void didInit (PlaceConfig config)
+    {
+    }
+
+    /**
+     * Called when the place manager is started up.
+     */
+    public void didStartup (PlaceObject plobj)
+    {
+    }
+
+    /**
+     * Called when the place manager is shut down.
+     */
+    public void didShutdown ()
+    {
+    }
+
+    /**
+     * Called when a body enters the place.
+     */
+    public void bodyEntered (int bodyOid)
+    {
+    }
+
+    /**
+     * Called when a body leaves the place.
+     */
+    public void bodyLeft (int bodyOid)
+    {
+    }
+
+    /**
+     * Called when the last body leaves the place.
+     */
+    public void placeBecameEmpty ()
+    {
+    }
+
+    /** A reference to the manager for which we are delegating. */
+    protected PlaceManager _plmgr;
+}