content: /*
   * -----------------------------------------------------------------------
   * Copyright 2012 - Alistair Rutherford - www.netthreads.co.uk
   * -----------------------------------------------------------------------
   * 
   * 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.
   * 
   */
  
  package com.netthreads.libgdx.event;
  
  import java.util.ArrayList;
  import java.util.LinkedList;
  import java.util.PriorityQueue;
  
  import com.badlogic.gdx.Gdx;
  import com.badlogic.gdx.scenes.scene2d.Actor;
  
  /**
   * Event source.
   * 
   * Broadcast events to subscribed observers.
   * 
   */
  public class ActorEventSource
  {
  	private final static int OBSERVERS_CAPACITY = 10;
  
  	private final static int MAX_EVENTS = 100;
  
  	private ArrayList<ActorEventObserver> observers;
  	private LinkedList<ActorEvent> pool;
  	private PriorityQueue<ActorEvent> events;
  
  	/**
  	 * Create observer list.
  	 * 
  	 */
  	public ActorEventSource()
  	{
  		observers = new ArrayList<ActorEventObserver>(OBSERVERS_CAPACITY);
  
  		pool = new LinkedList<ActorEvent>();
  		events = new PriorityQueue<ActorEvent>(MAX_EVENTS);
  
  		// Initialise the event pool.
  		for (int index = 0; index < MAX_EVENTS; index++)
  		{
  			pool.add(new ActorEvent());
  		}
  	}
  
  	/**
  	 * Update any observers.
  	 * 
  	 */
  	public void update()
  	{
  		if (events.size() > 0)
  		{
  			ActorEvent event = events.poll();
  
  			if (event != null)
  			{
  				boolean handled = false;
  
  				int size = observers.size();
  				for (int index = 0; index < size; index++)
  				{
  					handled = observers.get(index).handleEvent(event);
  
  					if (handled)
  						break;
  				}
  
  				// Place data event back onto pool.
  				pool.add(event);
  			}
  		}
  	}
  
  	/**
  	 * Add observer.
  	 * 
  	 * @param observer
  	 *            The target observer.
  	 */
  	public synchronized void addObserver(ActorEventObserver observer)
  	{
  		if (!observers.contains(observer))
  		{
  			observers.add(observer);
  		}
  	}
  
  	/**
  	 * Remove observer.
  	 * 
  	 * @param observer
  	 *            Target event observer.
  	 */
  	public synchronized void removeObserver(ActorEventObserver observer)
  	{
  		if (observers.contains(observer))
  		{
  			observers.remove(observer);
  		}
  	}
  
  	/**
  	 * Enqueue event
  	 * 
  	 * @param id
  	 *            The event id.
  	 * @param actor
  	 *            The associated actor.
  	 */
  	public void sendEvent(int id, Actor actor, int priority)
  	{
  		processEvent(id, actor, priority);
  	}
  
  	/**
  	 * Map event data to pooled event.
  	 * 
  	 * Place pooled event on to broadcast queue.
  	 * 
  	 * @param id
  	 *            The event id.
  	 * @param actor
  	 *            The associated actor.
  	 */
  	private void processEvent(int id, Actor actor, int priority)
  	{
  		ActorEvent event = pool.poll();
  
  		if (event == null)
  		{
  			event = new ActorEvent();
  
  			Gdx.app.log("ActorEventSource", "Warning, having to create pooled event, consider making the inital pool size larger, " + pool.size());
  		}
  
  		event.populate(id, actor, System.currentTimeMillis(), priority);
  
  		events.add(event);
  	}
  
  	/**
  	 * Clear structures.
  	 * 
  	 */
  	public void clear()
  	{
  		observers.clear();
  		events.clear();
  	}
  
  }
  