haiku.git

/*
 * Copyright 2001-2014 Haiku, Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *		Erik Jaesler, erik@cgsoftware.com
 */
#ifndef _MESSAGE_FILTER_H
#define _MESSAGE_FILTER_H


#include <Handler.h>


class BMessage;


// filter_hook Return Codes and Protocol
enum filter_result {
	B_SKIP_MESSAGE,
	B_DISPATCH_MESSAGE
};


typedef filter_result (*filter_hook)
	(BMessage* message, BHandler** target, BMessageFilter* filter);


// BMessageFilter invocation criteria
enum message_delivery {
	B_ANY_DELIVERY,
	B_DROPPED_DELIVERY,
	B_PROGRAMMED_DELIVERY
};

enum message_source {
	B_ANY_SOURCE,
	B_REMOTE_SOURCE,
	B_LOCAL_SOURCE
};


class BMessageFilter {
public:
								BMessageFilter(uint32 what,
									filter_hook func = NULL);
								BMessageFilter(message_delivery delivery,
									message_source source, filter_hook func = NULL);
								BMessageFilter(message_delivery delivery,
									message_source source, uint32 what,
									filter_hook func = NULL);
								BMessageFilter(const BMessageFilter& filter);
								BMessageFilter(const BMessageFilter* filter);
	virtual						~BMessageFilter();

			BMessageFilter&		operator=(const BMessageFilter& from);

			// Hook function; ignored if filter_hook is non-NULL
	virtual	filter_result		Filter(BMessage* message, BHandler** _target);

			message_delivery	MessageDelivery() const;
			message_source		MessageSource() const;
			uint32				Command() const;
			bool				FiltersAnyCommand() const;
			BLooper*			Looper() const;

private:
	friend class BLooper;
	friend class BHandler;

	virtual	void				_ReservedMessageFilter1();
	virtual	void				_ReservedMessageFilter2();

			void				SetLooper(BLooper* owner);
			filter_hook			FilterFunction() const;

			bool				fFiltersAny;
			uint32				fWhat;
			message_delivery	fDelivery;
			message_source		fSource;
			BLooper*			fLooper;
			filter_hook			fFilterFunction;

			uint32				_reserved[3];
};


#endif	// _MESSAGE_FILTER_H