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77 lines
2.6 KiB
77 lines
2.6 KiB
/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield |
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* |
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* This library is open source and may be redistributed and/or modified under |
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* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or |
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* (at your option) any later version. The full license is in LICENSE file |
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* included with this distribution, and on the openscenegraph.org website. |
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* |
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* This library is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* OpenSceneGraph Public License for more details. |
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*/ |
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#ifndef OSG_OBSERVER |
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#define OSG_OBSERVER 1 |
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#include <OpenThreads/Mutex> |
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#include <osg/Referenced> |
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#include <set> |
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namespace osg { |
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/** Observer base class for tracking when objects are unreferenced (there reference count goes to 0) and are being deleted.*/ |
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class OSG_EXPORT Observer |
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{ |
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public: |
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Observer(); |
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virtual ~Observer(); |
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/** objectDeleted is called when the observed object is about to be deleted. The observer will be automatically |
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* removed from the observerd objects observer set so there is no need for the objectDeleted implementation |
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* to call removeObserver() on the observed object. */ |
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virtual void objectDeleted(void*) {} |
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}; |
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/** Class used by osg::Referenced to track the observers associated with it.*/ |
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class OSG_EXPORT ObserverSet : public osg::Referenced |
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{ |
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public: |
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ObserverSet(const Referenced* observedObject); |
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Referenced* getObserverdObject() { return _observedObject; } |
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const Referenced* getObserverdObject() const { return _observedObject; } |
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/** "Lock" a Referenced object i.e., protect it from being deleted |
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* by incrementing its reference count. |
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* |
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* returns null if object doesn't exist anymore. */ |
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Referenced* addRefLock(); |
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inline OpenThreads::Mutex* getObserverSetMutex() const { return &_mutex; } |
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void addObserver(Observer* observer); |
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void removeObserver(Observer* observer); |
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void signalObjectDeleted(void* ptr); |
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typedef std::set<Observer*> Observers; |
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Observers& getObservers() { return _observers; } |
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const Observers& getObservers() const { return _observers; } |
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protected: |
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ObserverSet(const ObserverSet& rhs): osg::Referenced(rhs) {} |
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ObserverSet& operator = (const ObserverSet& /*rhs*/) { return *this; } |
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virtual ~ObserverSet(); |
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mutable OpenThreads::Mutex _mutex; |
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Referenced* _observedObject; |
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Observers _observers; |
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}; |
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} |
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#endif
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