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