<?php

/*
 * Copyright 2016 Johannes M. Schmitt <schmittjoh@gmail.com>
 *
 * Licensed 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.
 */

namespace JMS\Serializer\EventDispatcher;

interface EventDispatcherInterface
{
    /**
     * Returns whether there are listeners.
     *
     * @param string $eventName
     * @param string $class
     * @param string $format
     *
     * @return boolean
     */
    public function hasListeners($eventName, $class, $format);

    /**
     * Dispatches an event.
     *
     * The listeners/subscribers are called in the same order in which they
     * were added to the dispatcher.
     *
     * @param string $eventName
     * @param string $class
     * @param string $format
     * @param Event $event
     * @return void
     */
    public function dispatch($eventName, $class, $format, Event $event);

    /**
     * Adds a listener.
     *
     * @param string $eventName
     * @param callable $callable
     * @param string|null $class
     * @param string|null $format
     * @return void
     */
    public function addListener($eventName, $callable, $class = null, $format = null);

    /**
     * Adds a subscribers.
     *
     * @param EventSubscriberInterface $subscriber
     * @return void
     */
    public function addSubscriber(EventSubscriberInterface $subscriber);
}
