Signal.h

/*
  Copyright (C) 2005-2013 by Dr. Marc Boris Duerner
 
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
 
  As a special exception, you may use this file as part of a free
  software library without restriction. Specifically, if other files
  instantiate templates or use macros or inline functions from this
  file, or you compile this file and link it with other files to
  produce an executable, this file does not by itself cause the
  resulting executable to be covered by the GNU General Public
  License. This exception does not however invalidate any other
  reasons why the executable file might be covered by the GNU Library
  General Public License.
 
  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 GNU
  Lesser General Public License for more details.
 
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the:
  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  Boston, MA 02110-1301 USA
*/
 
#ifndef Pt_Signal_h
#define Pt_Signal_h
 
#include <Pt/Api.h>
#include <Pt/Void.h>
#include <Pt/Event.h>
#include <Pt/Slot.h>
#include <Pt/Function.h>
#include <Pt/Method.h>
#include <Pt/ConstMethod.h>
#include <Pt/Connectable.h>
#include <map>
 
namespace Pt {
 
class PT_API SignalBase : public Connectable
{
    public:
        struct PT_API Sentry
        {
            Sentry(SignalBase* signal);
 
            ~Sentry();
 
            void detachAll();
 
            void detach();
 
            bool operator!() const
            { return _signal == 0; }
 
            SignalBase* _signal;
            Sentry*     _next;
        };
 
        SignalBase();
 
        ~SignalBase();
 
        SignalBase& operator=(const SignalBase& other);
 
        virtual void onConnectionOpen(const Connection& c);
 
        virtual void onConnectionClose(const Connection& c);
 
    protected:
        void disconnectSlots();
 
        void disconnectSlot(const Slot&);
 
    private:
        Sentry* _sentry;
        bool _sending;
        bool _dirty;
};

template <typename... As>
class Signal : public SignalBase
{
    public:
        typedef Invokable<As...> InvokableT;
 
    public:
        Signal()
        { }

        Signal(const Signal& rhs)
        {
            SignalBase::operator=(rhs);
        }

        template <typename R>
        Connection connect(const BasicSlot<R, As...>& slot)
        {
            return Connection(*this, slot.clone());
        }

        void disconnect()
        {
            this->disconnectSlots();
        }

        template <typename R>
        void disconnect(const BasicSlot<R, As...>& slot)
        {
            this->disconnectSlot(slot);
        }

        void send(As... args)
        {
            if( Connectable::connections().empty() )
                return;
 
            SignalBase::Sentry sentry(this);
 
            std::list<Connection>::const_iterator it = Connectable::connections().begin();
            std::list<Connection>::const_iterator last = --Connectable::connections().end();
            while(true)
            {
                if( it->isValid() && it->sender() == this )
                {
                    const InvokableT* invokable =
                        static_cast<const InvokableT*>( it->callable() );
                    invokable->invoke(args...);
                }
 
                if( ! sentry )
                    return;
 
                if(it == last)
                    break;
 
                ++it;
            }
        }

        void operator()(As... args)
        {
            this->send(args...);
        }
};

template <typename... As>
class SignalSlot : public BasicSlot<void, As...>
{
    public:
        explicit SignalSlot(Signal<As...>& signal)
        : _method( signal, &Signal<As...>::send )
        {}
 
        // inherit doc
        Slot* clone() const
        {
            return new SignalSlot(*this);
        }
 
        // inherit doc
        virtual const Callback* callable() const
        {
            return &_method;
        }
 
        // inherit doc
        virtual void onConnect(const Connection& c)
        {
            _method.object().onConnectionOpen(c);
        }
 
        // inherit doc
        virtual void onDisconnect(const Connection& c)
        {
            _method.object().onConnectionClose(c);
        }
 
        // inherit doc
        virtual bool equals(const Slot& rhs) const
        {
            const SignalSlot* ss = dynamic_cast<const SignalSlot*>(&rhs);
            return ss ? (_method == ss->_method) : false;
        }
 
    private:
        Method<void, Signal<As...> , As...> _method;
};

template <typename... As>
SignalSlot<As...> slot(Signal<As...>& signal)
{
    return SignalSlot<As...>(signal);
}

template <typename R, typename... As>
Connection operator+=(Signal<As...>& signal, const BasicSlot<R, As...>& slot)
{
    return signal.connect(slot);
}

template <typename R, typename... As>
void operator-=(Signal<As...>& signal, const BasicSlot<R, As...>& slot)
{
    signal.disconnect(slot);
}
 
struct PT_API CompareEventTypeInfo
{
    bool operator()( const std::type_info* t1,
                     const std::type_info* t2 ) const;
};
 
template <>
class PT_API Signal<const Pt::Event&> : public Connectable
                                      , protected NonCopyable
{
    struct PT_API Sentry
    {
        Sentry(Signal* signal);
 
        ~Sentry();
 
        void detach();
 
        void detachAll();
 
        bool operator!() const
        { return _signal == 0; }
 
        Signal*  _signal;
        Sentry*  _next;
    };
 
    class IEventRoute
    {
        public:
            IEventRoute(Connection& target)
            : _target(target)
            { }
 
            virtual ~IEventRoute() {}
 
            virtual void route(const Pt::Event& ev)
            {
                typedef Invokable<const Pt::Event&> InvokableT;
                const InvokableT* invokable = static_cast<const InvokableT*>( _target.callable() );
                invokable->invoke(ev);
            }
 
            Connection& connection()
            { return _target; }
 
            bool isValid() const
            { return _target.isValid(); }
 
        private:
            Connection _target;
    };
 
    template <typename EventT>
    class EventRoute : public IEventRoute
    {
        public:
            EventRoute(Connection& target)
            : IEventRoute(target)
            { }
 
            virtual void route(const Pt::Event& ev)
            {
                typedef Invokable<const Pt::Event&> InvokableT;
                const InvokableT* invokable = static_cast<const InvokableT*>( connection().callable() );
 
                const EventT& event = static_cast<const EventT&>(ev);
                invokable->invoke(event);
            }
    };
 
    typedef std::multimap< const std::type_info*,
                           IEventRoute*,
                           CompareEventTypeInfo > RouteMap;
 
    public:
        Signal();
 
        ~Signal();
 
        void send(const Pt::Event& ev);
 
        template <typename EventT>
        Connection connect( const BasicSlot<void, const EventT&>& slot )
        {
            Connection conn( *this, slot.clone() );
            EventT* selectAddRouteOverload = 0;
            this->addRoute(conn, selectAddRouteOverload);
            return conn;
        }
 
        void disconnect();
 
        template <typename R, typename EventT>
        void disconnect(const BasicSlot<R, const EventT&>& slot)
        {
            this->removeRoute(slot);
        }
 
        virtual void onConnectionOpen(const Connection& c);
 
        virtual void onConnectionClose(const Connection& c);
 
    protected:
        void addRoute(Connection& conn, const Pt::Event*)
        {
            this->addRoute( 0, new IEventRoute(conn) );
        }
 
        template <typename EventT>
        void addRoute(Connection& conn, const EventT*)
        {
            const std::type_info& ti = typeid(EventT);
            this->addRoute( &ti, new EventRoute<EventT>(conn) );
        }
 
        void addRoute(const std::type_info* ti, IEventRoute* route);
 
        void removeRoute(const Slot& slot);
 
        // TODO: Pt 2.0 (better performance)
 
        //template <typename R>
        //void removeRoute(const BasicSlot<R, const Event&>& slot)
        //{
        //    this->removeRoute(0, slot);
        //}
 
        //template <typename R, typename EventT>
        //void removeRoute(const BasicSlot<R, const EventT&>& slot)
        //{
        //    const std::type_info& ti = typeid(EventT);
        //    this->removeRoute(&ti, slot);
        //}
 
        void removeRoute(const std::type_info* ti, const Slot& slot);
 
    private:
        RouteMap _routes;
        Sentry* _sentry;
        bool _sending;
        bool _dirty;
};
 
 
template <typename R, class EventT>
Connection operator +=(Signal<const Pt::Event&>& signal, const BasicSlot<R, EventT>& slot)
{
    return signal.connect( slot );
}
 
template <typename R>
Connection operator +=(Signal<const Pt::Event&>& signal, const BasicSlot<R, const Pt::Event&>& slot)
{
    return signal.connect( slot );
}
 
 
template <typename R, class EventT>
void operator -=(Signal<const Pt::Event&>& signal, const BasicSlot<R, EventT>& slot)
{
    signal.disconnect( slot );
}
 
template <typename R>
void operator -=(Signal<const Pt::Event&>& signal, const BasicSlot<R, const Pt::Event&>& slot)
{
    signal.disconnect( slot );
}
 
} // namespace Pt
 
#endif