From 6f89a0b53047dd1cc9fac8264639c30067bf6cb6 Mon Sep 17 00:00:00 2001
From: Carl Harris <ceharris@vt.edu>
Date: Wed, 16 Aug 2017 06:54:16 -0400
Subject: [PATCH] GUACAMOLE-364: listener interfaces now extend a common marker
 interface

---
 .../AuthenticationFailureListener.java        |  3 +-
 .../AuthenticationSuccessListener.java        |  2 +-
 .../net/event/listener/Listener.java          | 29 +++++++++++++++++++
 .../event/listener/TunnelCloseListener.java   |  4 +--
 .../event/listener/TunnelConnectListener.java |  2 +-
 5 files changed, 34 insertions(+), 6 deletions(-)
 create mode 100644 guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/Listener.java

diff --git a/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/AuthenticationFailureListener.java b/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/AuthenticationFailureListener.java
index 5fcd27b67..7fa619042 100644
--- a/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/AuthenticationFailureListener.java
+++ b/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/AuthenticationFailureListener.java
@@ -27,8 +27,7 @@ import org.apache.guacamole.net.event.AuthenticationFailureEvent;
  * after a user's authentication attempt fails. Note that this hook cannot
  * be used to cancel the authentication failure.
  */
-public interface AuthenticationFailureListener  {
-
+public interface AuthenticationFailureListener extends Listener {
     /**
      * Event hook which fires immediately after a user's authentication attempt
      * fails.
diff --git a/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/AuthenticationSuccessListener.java b/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/AuthenticationSuccessListener.java
index 7db072c36..cc5e01d57 100644
--- a/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/AuthenticationSuccessListener.java
+++ b/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/AuthenticationSuccessListener.java
@@ -28,7 +28,7 @@ import org.apache.guacamole.net.event.AuthenticationSuccessEvent;
  * the authenticationSucceeded() hook has the opportunity to cancel the
  * authentication and force it to fail.
  */
-public interface AuthenticationSuccessListener {
+public interface AuthenticationSuccessListener extends Listener {
 
     /**
      * Event hook which fires immediately after a user's authentication attempt
diff --git a/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/Listener.java b/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/Listener.java
new file mode 100644
index 000000000..72f859db1
--- /dev/null
+++ b/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/Listener.java
@@ -0,0 +1,29 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing,
+ *  software distributed under the License is distributed on an
+ *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ *  specific language governing permissions and limitations
+ *  under the License.
+ *
+ */
+
+package org.apache.guacamole.net.event.listener;
+
+/**
+ * A marker interface extended by all listener types. This interface is used
+ * simply to validate that a listener class identified in an extension
+ * actually implements some listener interface.
+ */
+public interface Listener {
+}
diff --git a/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/TunnelCloseListener.java b/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/TunnelCloseListener.java
index 784e4e932..99f2c04de 100644
--- a/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/TunnelCloseListener.java
+++ b/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/TunnelCloseListener.java
@@ -26,10 +26,10 @@ import org.apache.guacamole.net.event.TunnelCloseEvent;
  * A listener whose tunnelClosed() hook will fire immediately after an
  * existing tunnel is closed.
  */
-public interface TunnelCloseListener {
+public interface TunnelCloseListener extends Listener {
 
     /**
-     * Event hook which fires immediately after an existing tunnel is closed.
+     * Event hook which fires immediately before an existing tunnel is closed.
      * The return value of this hook dictates whether the tunnel is allowed to
      * be closed.
      *
diff --git a/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/TunnelConnectListener.java b/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/TunnelConnectListener.java
index da14fe277..7ac47e189 100644
--- a/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/TunnelConnectListener.java
+++ b/guacamole-ext/src/main/java/org/apache/guacamole/net/event/listener/TunnelConnectListener.java
@@ -26,7 +26,7 @@ import org.apache.guacamole.net.event.TunnelConnectEvent;
  * A listener whose tunnelConnected() hook will fire immediately after a new
  * tunnel is connected.
  */
-public interface TunnelConnectListener {
+public interface TunnelConnectListener extends Listener {
 
    /**
      * Event hook which fires immediately after a new tunnel is connected.