Event.php

<?php

class Event
{
    public $type;
    
    public $data = null;
    
    public $stopPropagation = false;
  
}

EventManager.php

<?php

class EventManager
{
    private $listenerList = array();
    
    public function addListener($listener) 
    {
    	$this->listenerList[] = $listener;
    }

    public function dispatch(Event $event)
    {
    	$type   = $event->type;
    	$result = null;

    	foreach ($this->listenerList as $listener) {
    		if ($event->stopPropagation) {
    			break;
    		}

    		if (method_exists($listener, $type)) {
    			$result = $listener->$type($event);
    		}
    	}

    	return $result;
    }
}