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Common Vaadin endpoint components

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/*
 * Copyright (c) 2013 ICM Uniwersytet Warszawski All rights reserved.
 * See LICENCE.txt file for licensing information.
 */
package io.imunity.vaadin.endpoint.common.bus;

import org.apache.logging.log4j.Logger;
import pl.edu.icm.unity.base.utils.Log;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Manages events and their listeners: producers can send events to this object, listeners register
 * and the bus will broadcast each event to all listeners registered for it.
 */
public class EventsBus 
{
	private static final Logger log = Log.getLogger(Log.U_SERVER_WEB, EventsBus.class);
	private final Map, List>> listeners = new HashMap, List>>();
	
	
	public synchronized  void addListener(EventListener listener, Class eventType)
	{
		List> typeListeners = listeners.get(eventType);
		if (typeListeners == null)
		{
			typeListeners = new ArrayList>(8);
			listeners.put(eventType, typeListeners);
		}
		typeListeners.add(listener);
	}
	
	public synchronized  void removeListener(EventListener listener, Class eventType)
	{
		List> typeListeners = listeners.get(eventType);
		if (typeListeners != null)
			typeListeners.remove(listener);
	}
	
	@SuppressWarnings({ "rawtypes", "unchecked" })
	public synchronized void fireEvent(Event event)
	{
		List> typeListeners = listeners.get(event.getClass());
		if (typeListeners == null)
			return;
		for (EventListener listener: typeListeners)
		{
			try
			{
				listener.handleEvent(event);
			} catch (Exception e)
			{
				log.error("Invoking event handler for event " + event.getClass() + " failed", e);
			}
		}
	}
}