GUACAMOLE-360: Add TunnelRequestService support for joining active connections.

guacamole/src/main/java/org/apache/guacamole/tunnel/TunnelRequestType.java

@@ -20,6 +20,7 @@
 package org.apache.guacamole.tunnel;
 
 import org.apache.guacamole.GuacamoleException;
+import org.apache.guacamole.net.auth.ActiveConnection;
 import org.apache.guacamole.net.auth.Connectable;
 import org.apache.guacamole.net.auth.Connection;
 import org.apache.guacamole.net.auth.ConnectionGroup;
@@ -57,6 +58,19 @@ public enum TunnelRequestType {
             return userContext.getConnectionGroupDirectory().get(identifier);
         }
 
+    },
+
+    /**
+     * An active Guacamole connection.
+     */
+    ACTIVE_CONNECTION("a", "active connection") {
+
+        @Override
+        public ActiveConnection getConnectable(UserContext userContext,
+                String identifier) throws GuacamoleException {
+            return userContext.getActiveConnectionDirectory().get(identifier);
+        }
+
     };
 
     /**

guacamole/src/main/webapp/app/navigation/types/ClientIdentifier.js

@@ -89,7 +89,14 @@ angular.module('client').factory('ClientIdentifier', ['$injector',
          *
          * @type String
          */
-        CONNECTION_GROUP : 'g'
+        CONNECTION_GROUP : 'g',
+
+        /**
+         * The type string for an active Guacamole connection.
+         *
+         * @type String
+         */
+        ACTIVE_CONNECTION : 'a'
 
     };