/**
 * $Id$
 * ***** BEGIN GPL/BL DUAL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version. The Blender
 * Foundation also sells licenses for use in proprietary software under
 * the Blender License.  See http://www.blender.org/BL/ for information
 * about this.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL/BL DUAL LICENSE BLOCK *****
 */

/**

 * $Id$
 * Copyright (C) 2001 NaN Technologies B.V.
 * @author	Maarten Gribnau
 * @date	May 14, 2001
 */

#ifndef _GHOST_EVENT_MANAGER_H_
#define _GHOST_EVENT_MANAGER_H_

#ifdef WIN32
#pragma warning (disable:4786) // suppress stl-MSVC debug info warning
#endif // WIN32

#include <deque>
#include <vector>

#include "GHOST_IEventConsumer.h"


/**
 * Manages an event stack and a list of event consumers.
 * The stack works on a FIFO (First In First Out) basis.
 * Events are pushed on the front of the stack and retrieved from the back.
 * Ownership of the event is transferred to the event manager as soon as an event is pushed.
 * Ownership of the event is transferred from the event manager as soon as an event is popped.
 * Events can be dispatched to the event consumers.
 */
class GHOST_EventManager
{
public:
	/**
	 * Constructor.
	 */
	GHOST_EventManager();

	/**
	 * Destructor.
	 */
	virtual ~GHOST_EventManager();

	/**
	 * Returns the number of events currently on the stack.
	 * @return The number of events on the stack.
	 */
	virtual	GHOST_TUns32	getNumEvents();

	/**
	 * Returns the number of events of a certain type currently on the stack.
	 * @param type The type of events to be counted.
	 * @return The number of events on the stack of this type.
	 */
	virtual	GHOST_TUns32	getNumEvents(GHOST_TEventType type);

	/**
	 * Return the event at the top of the stack without removal.
	 * Do not delete the event!
	 * @return The event at the top of the stack.
	 */
	virtual	GHOST_IEvent* peekEvent();

	/**
	 * Pushes an event on the stack.
	 * To dispatch it, call dispatchEvent() or dispatchEvents().
	 * Do not delete the event!
	 * @param event	The event to push on the stack.
	 */
	virtual	GHOST_TSuccess pushEvent(GHOST_IEvent* event);

	/**
	 * Dispatches the given event directly, bypassing the event stack.
	 * @return Indication as to whether any of the consumers handled the event.
	 */
	virtual bool dispatchEvent(GHOST_IEvent* event);

	/**
	 * Dispatches the event at the back of the stack.
	 * The event will be removed from the stack.
	 * @return Indication as to whether any of the consumers handled the event.
	 */
	virtual bool dispatchEvent();

	/**
	 * Dispatches all the events on the stack.
	 * The event stack will be empty afterwards.
	 * @return Indication as to whether any of the consumers handled the events.
	 */
	virtual bool dispatchEvents();

	/**
	 * Adds a consumer to the list of event consumers.
	 * @param consumer The consumer added to the list.
	 * @return Indication as to whether addition has succeeded.
	 */
	virtual GHOST_TSuccess addConsumer(GHOST_IEventConsumer* consumer);

	/**
	 * Removes a consumer from the list of event consumers.
	 * @param consumer The consumer removed from the list.
	 * @return Indication as to whether removal has succeeded.
	 */
	virtual GHOST_TSuccess removeConsumer(GHOST_IEventConsumer* consumer);

protected:
	/**
	 * Returns the event at the top of the stack and removes it.
	 * Delete the event after use!
	 * @return The event at the top of the stack.
	 */
	virtual	GHOST_IEvent* popEvent();

	/**
	 * Removes all events from the stack.
	 */
	virtual void disposeEvents();

	/** The event stack. */
	std::deque<GHOST_IEvent*> m_events;

	typedef std::vector<GHOST_IEventConsumer*> TConsumerVector;
	/** The list with event consumers. */
	TConsumerVector m_consumers;
};

#endif // _GHOST_EVENT_MANAGER_H_