Github user mike-jumper commented on a diff in the pull request:
https://github.com/apache/incubator-guacamole-client/pull/184#discussion_r143106271
--- Diff:
guacamole/src/main/java/org/apache/guacamole/extension/ListenerFactory.java ---
@@ -0,0 +1,256 @@
+/*
+ * 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.extension;
+
+import org.apache.guacamole.GuacamoleException;
+import org.apache.guacamole.GuacamoleSecurityException;
+import org.apache.guacamole.net.event.AuthenticationFailureEvent;
+import org.apache.guacamole.net.event.AuthenticationSuccessEvent;
+import org.apache.guacamole.net.event.TunnelCloseEvent;
+import org.apache.guacamole.net.event.TunnelConnectEvent;
+import org.apache.guacamole.net.event.listener.*;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * A factory that reflectively instantiates Listener objects for a given
+ * provider class.
+ */
+class ListenerFactory {
+
+ /**
+ * Creates all listeners represented by an instance of the given
provider class.
+ * <p>
+ * If a provider class implements the simple Listener interface, that
is the
+ * only listener type that will be returned. Otherwise, a list of
Listener
+ * objects that adapt the legacy listener interfaces will be returned.
+ *
+ * @param providerClass
+ * a class that represents a listener provider
+ *
+ * @return
+ * list of listeners represented by the given provider class
+ */
+ static List<Listener> createListeners(Class<?> providerClass) {
+
+ Object provider = ProviderFactory.newInstance("listener",
providerClass);
+
+ if (provider instanceof Listener) {
+ return Collections.singletonList((Listener) provider);
+ }
+
+ return createListenerAdapters(provider);
+
+ }
+
+ @SuppressWarnings("deprecation")
+ private static List<Listener> createListenerAdapters(Object provider) {
+
+ final List<Listener> listeners = new ArrayList<Listener>();
+
+ if (provider instanceof AuthenticationSuccessListener) {
+ listeners.add(new AuthenticationSuccessListenerAdapter(
+ (AuthenticationSuccessListener) provider));
+ }
+
+ if (provider instanceof AuthenticationFailureListener) {
+ listeners.add(new AuthenticationFailureListenerAdapter(
+ (AuthenticationFailureListener) provider));
+ }
+
+ if (provider instanceof TunnelConnectListener) {
+ listeners.add(new TunnelConnectListenerAdapter(
+ (TunnelConnectListener) provider));
+ }
+
+ if (provider instanceof TunnelCloseListener) {
+ listeners.add(new TunnelCloseListenerAdapter(
+ (TunnelCloseListener) provider));
+ }
+
+ return listeners;
+
+ }
+
+ /**
+ * An adapter the allows an AuthenticationSuccessListener to be used
+ * as an ordinary Listener.
+ */
+ @SuppressWarnings("deprecation")
+ private static class AuthenticationSuccessListenerAdapter implements
Listener {
+
+ private final AuthenticationSuccessListener delegate;
+
+ /**
+ * Constructs a new adapter.
+ *
+ * @param delegate
+ * the delegate listener
+ */
+ AuthenticationSuccessListenerAdapter(AuthenticationSuccessListener
delegate) {
+ this.delegate = delegate;
+ }
+
+ /**
+ * Handles an AuthenticationSuccessEvent by passing the event to
the delegate
+ * listener. If the delegate returns false, the adapter throws a
GuacamoleException
+ * to veto the authentication success event. All other event types
are ignored.
+ *
+ * @param event
+ * an object that describes the subject event
+ *
+ * @throws GuacamoleException
+ * if thrown by the delegate listener
+ */
+ @Override
+ public void handleEvent(Object event) throws GuacamoleException {
+ if (event instanceof AuthenticationSuccessEvent) {
+ if
(!delegate.authenticationSucceeded((AuthenticationSuccessEvent) event)) {
+ throw new GuacamoleSecurityException(
+ "listener vetoed successful authentication");
+ }
+ }
+ }
+
+ }
+
+ /**
+ * An adapter the allows an AuthenticationFailureListener to be used
+ * as an ordinary Listener.
+ */
+ @SuppressWarnings("deprecation")
+ private static class AuthenticationFailureListenerAdapter implements
Listener {
+
+ private final AuthenticationFailureListener delegate;
+
+ /**
+ * Constructs a new adapter.
+ *
+ * @param delegate
+ * the delegate listener
+ */
+ AuthenticationFailureListenerAdapter(AuthenticationFailureListener
delegate) {
+ this.delegate = delegate;
+ }
+
+ /**
+ * Handles an AuthenticationFailureEvent by passing the event to
the delegate
+ * listener. All other event types are ignored.
+ *
+ * @param event
+ * an object that describes the subject event
+ *
+ * @throws GuacamoleException
+ * if thrown by the delegate listener
+ */
+ @Override
+ public void handleEvent(Object event) throws GuacamoleException {
+ if (event instanceof AuthenticationFailureEvent) {
+ delegate.authenticationFailed((AuthenticationFailureEvent)
event);
+ }
+ }
+
+ }
+
+ /**
+ * An adapter the allows a TunnelConnectListener to be used as an
ordinary
+ * Listener.
+ */
+ @SuppressWarnings("deprecation")
+ private static class TunnelConnectListenerAdapter implements Listener {
+
+ private final TunnelConnectListener delegate;
+
+ /**
+ * Constructs a new adapter.
+ *
+ * @param delegate
+ * the delegate listener
+ */
+ TunnelConnectListenerAdapter(TunnelConnectListener delegate) {
+ this.delegate = delegate;
+ }
+
+ /**
+ * Handles a TunnelConnectEvent by passing the event to the
delegate listener.
+ * If the delegate returns false, the adapter throws a
GuacamoleException
+ * to veto the tunnel connect event. All other event types are
ignored.
+ *
+ * @param event
+ * an object that describes the subject event
+ *
+ * @throws GuacamoleException
+ * if thrown by the delegate listener
+ */
+ @Override
+ public void handleEvent(Object event) throws GuacamoleException {
+ if (event instanceof TunnelConnectEvent) {
+ if (!delegate.tunnelConnected((TunnelConnectEvent) event))
{
+ throw new GuacamoleException("listener vetoed tunnel
connection");
+ }
+ }
+ }
+
+ }
+
+ /**
+ * An adapter the allows a TunnelCloseListener to be used as an
ordinary
+ * Listener.
+ */
+ @SuppressWarnings("deprecation")
+ private static class TunnelCloseListenerAdapter implements Listener {
+
+ private final TunnelCloseListener delegate;
+
+ /**
+ * Constructs a new adapter.
+ *
+ * @param delegate
+ * the delegate listener
--- End diff --
Should be sentence case, plus a period.
---
