notification.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * Additional copyright for this file:
 * Copyright (C) 1995-1997 Presto Studios, Inc.
 *
 * 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 3 of the License, or
 * (at your option) any later version.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef PEGASUS_NOTIFICATION_H
#define PEGASUS_NOTIFICATION_H

#include "common/array.h"
#include "common/list.h"

#include "pegasus/types.h"
#include "pegasus/util.h"

namespace Pegasus {

class NotificationManager;
class NotificationReceiver;

struct ReceiverEntry {
    NotificationReceiver *receiver;
    NotificationFlags mask;
};

int operator==(const ReceiverEntry &entry1, const ReceiverEntry &entry2);
int operator!=(const ReceiverEntry &entry1, const ReceiverEntry &entry2);

typedef Common::Array<ReceiverEntry> ReceiverList;

/*
    A notification can have 32 flags associated with it, which can be user-defined.
*/

class Notification : public IDObject {
friend class NotificationManager;

public:
    Notification(const NotificationID id, NotificationManager *owner);
    virtual ~Notification();

    // notifyMe will have this receiver notified when any of the specified notification
    // flags are set.
    // If there is already a notification set for this receiver, notifyMe does a bitwise
    // OR with the receiver's current notification flags.

    // Can selectively set or clear notification bits by using the flags and mask argument.

    void notifyMe(NotificationReceiver*, NotificationFlags flags, NotificationFlags mask);
    void cancelNotification(NotificationReceiver *receiver);

    void setNotificationFlags(NotificationFlags flags,  NotificationFlags mask);
    NotificationFlags getNotificationFlags() { return _currentFlags; }

    void clearNotificationFlags() { setNotificationFlags(0, ~(NotificationFlags)0); }

protected:
    void checkReceivers();

    NotificationManager *_owner;
    ReceiverList _receivers;
    NotificationFlags _currentFlags;
};

class NotificationReceiver {
friend class Notification;

public:
    NotificationReceiver();
    virtual ~NotificationReceiver();

protected:
    // receiveNotification is called automatically whenever a notification that this
    // receiver depends on has its flags set

    virtual void receiveNotification(Notification *, const NotificationFlags);
    virtual void newNotification(Notification *notification);

private:
    Notification *_notification;
};

typedef Common::List<Notification *> NotificationList;

class NotificationManager : public NotificationReceiver {
friend class Notification;

public:
    NotificationManager();
    ~NotificationManager() override;

    void checkNotifications();

protected:
    void addNotification(Notification *notification);
    void removeNotification(Notification *notification);
    void detachNotifications();

    NotificationList _notifications;
};

} // End of namespace Pegasus

#endif