--- /dev/null
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\EventDispatcher;
+
+/**
+ * A read-only proxy for an event dispatcher.
+ *
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ */
+class ImmutableEventDispatcher implements EventDispatcherInterface
+{
+ /**
+ * The proxied dispatcher.
+ *
+ * @var EventDispatcherInterface
+ */
+ private $dispatcher;
+
+ /**
+ * Creates an unmodifiable proxy for an event dispatcher.
+ *
+ * @param EventDispatcherInterface $dispatcher The proxied event dispatcher
+ */
+ public function __construct(EventDispatcherInterface $dispatcher)
+ {
+ $this->dispatcher = $dispatcher;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function dispatch($eventName, Event $event = null)
+ {
+ return $this->dispatcher->dispatch($eventName, $event);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function addListener($eventName, $listener, $priority = 0)
+ {
+ throw new \BadMethodCallException('Unmodifiable event dispatchers must not be modified.');
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function addSubscriber(EventSubscriberInterface $subscriber)
+ {
+ throw new \BadMethodCallException('Unmodifiable event dispatchers must not be modified.');
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function removeListener($eventName, $listener)
+ {
+ throw new \BadMethodCallException('Unmodifiable event dispatchers must not be modified.');
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function removeSubscriber(EventSubscriberInterface $subscriber)
+ {
+ throw new \BadMethodCallException('Unmodifiable event dispatchers must not be modified.');
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getListeners($eventName = null)
+ {
+ return $this->dispatcher->getListeners($eventName);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getListenerPriority($eventName, $listener)
+ {
+ return $this->dispatcher->getListenerPriority($eventName, $listener);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function hasListeners($eventName = null)
+ {
+ return $this->dispatcher->hasListeners($eventName);
+ }
+}