We can't use the type systesm to enforce our requirements, but we can use

obtain containment and a stack of specifically typed outer class references to
accomplish what we need without misleading casts.

This will require changes to Yohoho which I shall make forthwith.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@6320 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/main/java/com/threerings/crowd/data/BodyObject.java

@@ -25,7 +25,9 @@ import javax.annotation.Generated;
 import com.threerings.util.Name;
 
 import com.threerings.presents.data.ClientObject;
+import com.threerings.presents.data.Permission;
 
+import com.threerings.crowd.chat.data.ChatCodes;
 import com.threerings.crowd.chat.data.SpeakObject;
 
 /**
@@ -210,6 +212,26 @@ public class BodyObject extends ClientObject
         return OccupantInfo.X_STATUS[status];
     }
 
+    @Override
+    protected PermissionPolicy createPermissionPolicy ()
+    {
+        return new CrowdPermissionPolicy();
+    }
+
+    protected class CrowdPermissionPolicy extends PermissionPolicy
+    {
+        @Override // from PermissionPolicy
+        public String checkAccess (Permission perm, Object context) {
+            if (perm == ChatCodes.BROADCAST_ACCESS) {
+                return getTokens().isAdmin() ? null : ACCESS_DENIED;
+            } else if (perm == ChatCodes.CHAT_ACCESS) {
+                return null;
+            } else {
+                return super.checkAccess(perm, context);
+            }
+        }
+    }
+
     /** The default (no tokens) access control. */
     protected static final TokenRing EMPTY_TOKENS = new TokenRing();
 }

src/main/java/com/threerings/crowd/data/CrowdPermissionPolicy.java

@@ -1,49 +0,0 @@
-//
-// $Id$
-//
-// Narya library - tools for developing networked games
-// Copyright (C) 2002-2010 Three Rings Design, Inc., All Rights Reserved
-// http://code.google.com/p/narya/
-//
-// This library is free software; you can redistribute it and/or modify it
-// under the terms of the GNU Lesser General Public License as published
-// by the Free Software Foundation; either version 2.1 of the License, or
-// (at your option) any later version.
-//
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-// Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public
-// License along with this library; if not, write to the Free Software
-// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-
-package com.threerings.crowd.data;
-
-import com.threerings.presents.data.ClientObject;
-import com.threerings.presents.data.Permission;
-import com.threerings.presents.data.PermissionPolicy;
-
-import com.threerings.crowd.chat.data.ChatCodes;
-
-/**
- * Implements some Crowd permissions. Note: this is stored <em>inside</em> a {@link BodyObject} and
- * will only ever be called by a BodyObject. It is sent over the wire and must be usable on the
- * client and server.
- */
-public class CrowdPermissionPolicy extends PermissionPolicy
-{
-    @Override // from PermissionPolicy
-    public String checkAccess (ClientObject clobj, Permission perm, Object context)
-    {
-        BodyObject body = (BodyObject)clobj;
-        if (perm == ChatCodes.BROADCAST_ACCESS) {
-            return body.getTokens().isAdmin() ? null : ACCESS_DENIED;
-        } else if (perm == ChatCodes.CHAT_ACCESS) {
-            return null;
-        } else {
-            return super.checkAccess(clobj, perm, context);
-        }
-    }
-}

src/main/java/com/threerings/crowd/data/TokenRing.java

@@ -26,7 +26,7 @@ import com.threerings.io.SimpleStreamableObject;
 /**
  * Defines access control tokens that convey certain privileges to users.
  *
- * @see CrowdPermissionPolicy
+ * @see BodyObject#CrowdPermissionPolicy
  */
 public class TokenRing extends SimpleStreamableObject
 {

src/main/java/com/threerings/crowd/server/CrowdClientResolver.java

@@ -22,12 +22,10 @@
 package com.threerings.crowd.server;
 
 import com.threerings.presents.data.ClientObject;
-import com.threerings.presents.data.PermissionPolicy;
 import com.threerings.presents.server.ClientLocal;
 import com.threerings.presents.server.ClientResolver;
 
 import com.threerings.crowd.data.BodyObject;
-import com.threerings.crowd.data.CrowdPermissionPolicy;
 
 /**
  * Used to configure crowd-specific client object data.
@@ -45,10 +43,4 @@ public class CrowdClientResolver extends ClientResolver
     {
         return new BodyLocal();
     }
-
-    @Override // from ClientResolver
-    public PermissionPolicy createPermissionPolicy ()
-    {
-        return new CrowdPermissionPolicy();
-    }
 }

src/main/java/com/threerings/presents/data/ClientObject.java

@@ -54,14 +54,6 @@ public class ClientObject extends DObject
     /** Used to publish all invocation service receivers registered on this client. */
     public DSet<InvocationReceiver.Registration> receivers = DSet.newDSet();
 
-    /**
-     * Configures this client with a permissions policy. This is done during client resolution.
-     */
-    public void setPermissionPolicy (PermissionPolicy policy)
-    {
-        _permPolicy = policy;
-    }
-
     /**
      * Returns a short string identifying this client.
      */
@@ -80,7 +72,10 @@ public class ClientObject extends DObject
      */
     public String checkAccess (Permission perm, Object context)
     {
-        return _permPolicy.checkAccess(this, perm, context);
+        if (_permPolicy == null) {
+            _permPolicy = createPermissionPolicy();
+        }
+        return _permPolicy.checkAccess(perm, context);
     }
 
     /**
@@ -203,8 +198,34 @@ public class ClientObject extends DObject
     }
     // AUTO-GENERATED: METHODS END
 
+    protected PermissionPolicy createPermissionPolicy ()
+    {
+        return new PermissionPolicy();
+    }
+
+    /**
+     * ClientObject derived classes can extend this class to provide more sophisticated permission
+     * policies, and should return their customized classes from {@link #createPermissionPolicy}.
+     * This class, and its children must <em>only</em> make use of data available in the
+     * ClientObject (and its children). Permissions may be checked on the client or server.
+     */
+    protected class PermissionPolicy implements InvocationCodes
+    {
+        /**
+         * Returns null if the specified client has the specified permission, an error code
+         * explaining the lack of access if they do not. {@link InvocationCodes#ACCESS_DENIED}
+         * should be returned if no more specific explanation is available.
+         *
+         * @param perm the permission to be checked.
+         * @param context a potential context for the request, if any.
+         */
+        public String checkAccess (Permission perm, Object context) {
+            return ACCESS_DENIED; // by default, you can't do it!
+        }
+    }
+
     /** Handles our fine-grained permissions. */
-    protected PermissionPolicy _permPolicy;
+    protected transient PermissionPolicy _permPolicy;
 
     /** Used to reference count resolved client objects. */
     protected transient int _references;

src/main/java/com/threerings/presents/data/PermissionPolicy.java

@@ -1,48 +0,0 @@
-//
-// $Id$
-//
-// Narya library - tools for developing networked games
-// Copyright (C) 2002-2010 Three Rings Design, Inc., All Rights Reserved
-// http://code.google.com/p/narya/
-//
-// This library is free software; you can redistribute it and/or modify it
-// under the terms of the GNU Lesser General Public License as published
-// by the Free Software Foundation; either version 2.1 of the License, or
-// (at your option) any later version.
-//
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-// Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public
-// License along with this library; if not, write to the Free Software
-// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-
-package com.threerings.presents.data;
-
-import com.threerings.io.Streamable;
-
-/**
- * Encapsulates a fine-grained permissions policy. The default policy is to deny access to
- * everything, systems using fine-grained permissions should create a custom policy and provide it
- * at client resolution time via the ClientResolver.
- */
-public class PermissionPolicy
-    implements Streamable, InvocationCodes
-{
-    /**
-     * Returns null if the specified client has the specified permission, an error code explaining
-     * the lack of access if they do not. {@link InvocationCodes#ACCESS_DENIED} should be returned
-     * if no more specific explanation is available.
-     *
-     * @param clobj the client
-     * @param perm what permission they'd like to know if they have
-     * @param context potential context for the request, if that matters
-     */
-    public String checkAccess (ClientObject clobj, Permission perm, Object context)
-    {
-        // by default, you can't do it!
-        return ACCESS_DENIED;
-    }
-}

src/main/java/com/threerings/presents/server/ClientManager.java

@@ -298,7 +298,6 @@ public class ClientManager
                 public void run () {
                     ClientObject clobj = fclr.createClientObject();
                     clobj.setLocal(ClientLocal.class, fclr.createLocalAttribute());
-                    clobj.setPermissionPolicy(fclr.createPermissionPolicy());
                     fclr.objectAvailable(_omgr.registerObject(clobj));
                 }
             });

src/main/java/com/threerings/presents/server/ClientResolver.java

@@ -32,7 +32,6 @@ import com.threerings.util.Name;
 
 import com.threerings.presents.annotation.MainInvoker;
 import com.threerings.presents.data.ClientObject;
-import com.threerings.presents.data.PermissionPolicy;
 import com.threerings.presents.dobj.RootDObjectManager;
 
 import static com.threerings.presents.Log.log;
@@ -87,14 +86,6 @@ public class ClientResolver extends Invoker.Unit
         return new ClientLocal();
     }
 
-    /**
-     * Creates a permission policy for use by our client.
-     */
-    public PermissionPolicy createPermissionPolicy ()
-    {
-        return new PermissionPolicy();
-    }
-
     /**
      * Called once our client object is registered with the distributed object system.
      */