/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
 *
 * This library is open source and may be redistributed and/or modified under
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 *
 * This library 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
 * OpenSceneGraph Public License for more details.
*/

#include <osg/ObserverNodePath>
#include <osg/Notify>

using namespace osg;

Observer::Observer()
{
}

Observer::~Observer()
{
}

ObserverSet::ObserverSet(const Referenced* observedObject):
    _observedObject(const_cast<Referenced*>(observedObject))
{
    //OSG_NOTICE<<"ObserverSet::ObserverSet() "<<this<<std::endl;
}

ObserverSet::~ObserverSet()
{
    //OSG_NOTICE<<"ObserverSet::~ObserverSet() "<<this<<", _observers.size()="<<_observers.size()<<std::endl;
}

void ObserverSet::addObserver(Observer* observer)
{
    //OSG_NOTICE<<"ObserverSet::addObserver("<<observer<<") "<<this<<std::endl;
    OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);
    _observers.insert(observer);
}

void ObserverSet::removeObserver(Observer* observer)
{
    //OSG_NOTICE<<"ObserverSet::removeObserver("<<observer<<") "<<this<<std::endl;
    OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);
    _observers.erase(observer);
}

Referenced* ObserverSet::addRefLock()
{
    OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);

    if (!_observedObject) return 0;

    int refCount = _observedObject->ref();
    if (refCount == 1)
    {
        // The object is in the process of being deleted, but our
        // objectDeleted() method hasn't been run yet (and we're
        // blocking it -- and the final destruction -- with our lock).
        _observedObject->unref_nodelete();
        return 0;
    }

    return _observedObject;
}

void ObserverSet::signalObjectDeleted(void* ptr)
{
    OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);

    for(Observers::iterator itr = _observers.begin();
        itr != _observers.end();
        ++itr)
    {
        (*itr)->objectDeleted(ptr);
    }
    _observers.clear();

    // reset the observed object so that we know that it's now detached.
    _observedObject = 0;
}