Chris@16: // Boost.Signals2 library
Chris@16: 
Chris@16: // Copyright Frank Mori Hess 2007-2008.
Chris@16: // Copyright Timmo Stange 2007.
Chris@16: // Copyright Douglas Gregor 2001-2004. Use, modification and
Chris@16: // distribution is subject to the Boost Software License, Version
Chris@16: // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: // For more information, see http://www.boost.org
Chris@16: 
Chris@16: #ifndef BOOST_SIGNALS2_SLOT_BASE_HPP
Chris@16: #define BOOST_SIGNALS2_SLOT_BASE_HPP
Chris@16: 
Chris@16: #include <boost/shared_ptr.hpp>
Chris@16: #include <boost/weak_ptr.hpp>
Chris@16: #include <boost/signals2/detail/foreign_ptr.hpp>
Chris@16: #include <boost/signals2/expired_slot.hpp>
Chris@16: #include <boost/signals2/signal_base.hpp>
Chris@16: #include <boost/throw_exception.hpp>
Chris@16: #include <boost/variant/apply_visitor.hpp>
Chris@16: #include <boost/variant/variant.hpp>
Chris@16: #include <vector>
Chris@16: 
Chris@16: namespace boost
Chris@16: {
Chris@16:   namespace signals2
Chris@16:   {
Chris@16:     namespace detail
Chris@16:     {
Chris@16:       class tracked_objects_visitor;
Chris@101:       class trackable_pointee;
Chris@16: 
Chris@101:       typedef boost::variant<boost::weak_ptr<trackable_pointee>, boost::weak_ptr<void>, detail::foreign_void_weak_ptr > void_weak_ptr_variant;
Chris@16:       typedef boost::variant<boost::shared_ptr<void>, detail::foreign_void_shared_ptr > void_shared_ptr_variant;
Chris@16:       class lock_weak_ptr_visitor
Chris@16:       {
Chris@16:       public:
Chris@16:         typedef void_shared_ptr_variant result_type;
Chris@16:         template<typename WeakPtr>
Chris@16:         result_type operator()(const WeakPtr &wp) const
Chris@16:         {
Chris@16:           return wp.lock();
Chris@16:         }
Chris@101:         // overload to prevent incrementing use count of shared_ptr associated
Chris@101:         // with signals2::trackable objects
Chris@101:         result_type operator()(const weak_ptr<trackable_pointee> &) const
Chris@101:         {
Chris@101:           return boost::shared_ptr<void>();
Chris@101:         }
Chris@16:       };
Chris@16:       class expired_weak_ptr_visitor
Chris@16:       {
Chris@16:       public:
Chris@16:         typedef bool result_type;
Chris@16:         template<typename WeakPtr>
Chris@16:         bool operator()(const WeakPtr &wp) const
Chris@16:         {
Chris@16:           return wp.expired();
Chris@16:         }
Chris@16:       };
Chris@16:     }
Chris@16: 
Chris@16:     class slot_base
Chris@16:     {
Chris@16:     public:
Chris@16:       typedef std::vector<detail::void_weak_ptr_variant> tracked_container_type;
Chris@16:       typedef std::vector<detail::void_shared_ptr_variant> locked_container_type;
Chris@16: 
Chris@16:       const tracked_container_type& tracked_objects() const {return _tracked_objects;}
Chris@16:       locked_container_type lock() const
Chris@16:       {
Chris@16:         locked_container_type locked_objects;
Chris@16:         tracked_container_type::const_iterator it;
Chris@16:         for(it = tracked_objects().begin(); it != tracked_objects().end(); ++it)
Chris@16:         {
Chris@16:           locked_objects.push_back(apply_visitor(detail::lock_weak_ptr_visitor(), *it));
Chris@16:           if(apply_visitor(detail::expired_weak_ptr_visitor(), *it))
Chris@16:           {
Chris@16:             boost::throw_exception(expired_slot());
Chris@16:           }
Chris@16:         }
Chris@16:         return locked_objects;
Chris@16:       }
Chris@16:       bool expired() const
Chris@16:       {
Chris@16:         tracked_container_type::const_iterator it;
Chris@16:         for(it = tracked_objects().begin(); it != tracked_objects().end(); ++it)
Chris@16:         {
Chris@16:           if(apply_visitor(detail::expired_weak_ptr_visitor(), *it)) return true;
Chris@16:         }
Chris@16:         return false;
Chris@16:       }
Chris@16:     protected:
Chris@16:       friend class detail::tracked_objects_visitor;
Chris@16: 
Chris@16:       void track_signal(const signal_base &signal)
Chris@16:       {
Chris@16:         _tracked_objects.push_back(signal.lock_pimpl());
Chris@16:       }
Chris@16: 
Chris@16:       tracked_container_type _tracked_objects;
Chris@16:     };
Chris@16:   }
Chris@16: } // end namespace boost
Chris@16: 
Chris@16: #endif // BOOST_SIGNALS2_SLOT_BASE_HPP