From 144d716a42072bd59f6c99e95e86be4486285782 Mon Sep 17 00:00:00 2001
From: Pavel Labath <pavelo@centrum.sk>
Date: Mon, 2 May 2011 15:10:42 +0200
Subject: Simplify Slot.hh

Replace CallbackHolder, FunctorHolder and SlotHolder with a (smaller) set of polymorphic classes.
SignalHolder now stores a (smart) pointer to the class.
---
 src/FbTk/Signal.hh |  49 +++++-----
 src/FbTk/Slot.hh   | 275 +++++++++--------------------------------------------
 2 files changed, 70 insertions(+), 254 deletions(-)

diff --git a/src/FbTk/Signal.hh b/src/FbTk/Signal.hh
index 79d001f..71a4d6e 100644
--- a/src/FbTk/Signal.hh
+++ b/src/FbTk/Signal.hh
@@ -22,6 +22,7 @@
 #ifndef FBTK_SIGNAL_HH
 #define FBTK_SIGNAL_HH
 
+#include "RefCount.hh"
 #include "Slot.hh"
 #include <list>
 #include <map>
@@ -49,7 +50,7 @@ public:
     };
 
     /// Do not use this type outside this class
-    typedef std::list<SlotHolder> SlotList;
+    typedef std::list<RefCount<SlotBase> > SlotList;
 
     typedef SlotList::iterator Iterator;
     typedef Iterator SlotID;
@@ -91,7 +92,7 @@ protected:
     Iterator end() { return m_slots.end(); }
 
     /// Connect a slot to this signal. Must only be called by child classes.
-    SlotID connect(const SlotHolder& slot) {
+    SlotID connect(const RefCount<SlotBase>& slot) {
         return m_slots.insert(m_slots.end(), slot);
     }
 
@@ -111,16 +112,17 @@ template <typename ReturnType,
           typename Arg1 = SigImpl::EmptyArg, typename Arg2 = SigImpl::EmptyArg, typename Arg3 = SigImpl::EmptyArg >
 class Signal: public SigImpl::SignalHolder {
 public:
-    typedef SigImpl::Slot3<ReturnType, Arg1, Arg2, Arg3> SlotType;
-
     void emit(Arg1 arg1, Arg2 arg2, Arg3 arg3) {
         for ( Iterator it = begin(); it != end(); ++it ) {
-            static_cast<SlotType&>(*it)(arg1, arg2, arg3);
+            static_cast<SigImpl::SlotBase3<ReturnType, Arg1, Arg2, Arg3> &>(**it)(arg1, arg2, arg3);
         }
     }
 
-    SlotID connect(const SlotType& slot) {
-        return SignalHolder::connect(slot);
+    template<typename Functor>
+    SlotID connect(const Functor& functor) {
+        return SignalHolder::connect(FbTk::RefCount<SigImpl::SlotBase>(
+                        new SigImpl::Slot3<ReturnType, Arg1, Arg2, Arg3, Functor>(functor)
+                    ));
     }
 };
 
@@ -128,16 +130,17 @@ public:
 template <typename ReturnType, typename Arg1, typename Arg2>
 class Signal<ReturnType, Arg1, Arg2, SigImpl::EmptyArg>: public SigImpl::SignalHolder {
 public:
-    typedef SigImpl::Slot2<ReturnType, Arg1, Arg2> SlotType;
-
     void emit(Arg1 arg1, Arg2 arg2) {
         for ( Iterator it = begin(); it != end(); ++it ) {
-            static_cast<SlotType&>(*it)(arg1, arg2);
+            static_cast<SigImpl::SlotBase2<ReturnType, Arg1, Arg2> &>(**it)(arg1, arg2);
         }
     }
 
-    SlotID connect(const SlotType& slot) {
-        return SignalHolder::connect(slot);
+    template<typename Functor>
+    SlotID connect(const Functor& functor) {
+        return SignalHolder::connect(FbTk::RefCount<SigImpl::SlotBase>(
+                        new SigImpl::Slot2<ReturnType, Arg1, Arg2, Functor>(functor)
+                    ));
     }
 };
 
@@ -145,16 +148,17 @@ public:
 template <typename ReturnType, typename Arg1>
 class Signal<ReturnType, Arg1, SigImpl::EmptyArg, SigImpl::EmptyArg>: public SigImpl::SignalHolder {
 public:
-    typedef SigImpl::Slot1<ReturnType, Arg1> SlotType;
-
     void emit(Arg1 arg) {
         for ( Iterator it = begin(); it != end(); ++it ) {
-            static_cast<SlotType&>(*it)(arg);
+            static_cast<SigImpl::SlotBase1<ReturnType, Arg1> &>(**it)(arg);
         }
     }
 
-    SlotID connect(const SlotType& slot) {
-        return SignalHolder::connect(slot);
+    template<typename Functor>
+    SlotID connect(const Functor& functor) {
+        return SignalHolder::connect(FbTk::RefCount<SigImpl::SlotBase>(
+                        new SigImpl::Slot1<ReturnType, Arg1, Functor>(functor)
+                    ));
     }
 };
 
@@ -162,16 +166,17 @@ public:
 template <typename ReturnType>
 class Signal<ReturnType, SigImpl::EmptyArg, SigImpl::EmptyArg, SigImpl::EmptyArg>: public SigImpl::SignalHolder {
 public:
-    typedef SigImpl::Slot0<ReturnType> SlotType;
-
     void emit() {
         for ( Iterator it = begin(); it != end(); ++it ) {
-            static_cast<SlotType&>(*it)();
+            static_cast<SigImpl::SlotBase0<ReturnType> &>(**it)();
         }
     }
 
-    SlotID connect(const SlotType& slot) {
-        return SignalHolder::connect(slot);
+    template<typename Functor>
+    SlotID connect(const Functor& functor) {
+        return SignalHolder::connect(FbTk::RefCount<SigImpl::SlotBase>(
+                        new SigImpl::Slot0<ReturnType, Functor>(functor)
+                    ));
     }
 };
 
diff --git a/src/FbTk/Slot.hh b/src/FbTk/Slot.hh
index 9080d53..3daca4e 100644
--- a/src/FbTk/Slot.hh
+++ b/src/FbTk/Slot.hh
@@ -27,268 +27,79 @@ namespace FbTk {
 /// \namespace Implementation details for signals, do not use anything in this namespace
 namespace SigImpl {
 
-class CallbackHolder;
-
-/// Placeholder type for typed callbacks
-typedef void* (*CallbackFunc)(void *);
-/// Clone function callback type for cloning typed callback holders
-typedef CallbackHolder* (*CloneFunc)(CallbackHolder*);
-/// Kill function callback type for destroying type specific information in
-/// FunctorHolder
-typedef void (*KillFunc)(CallbackHolder*);
-
-/// Holds clone, functor callback, and the kill function for FunctorHolder.
-class CallbackHolder {
+class SlotBase {
 public:
-    /**
-     * @param callback The callback to call when a slot receives a signal.
-     * @param clone The callback to use for cloning a type specific instance of
-     *              this classinstance.
-     * @param kill The callback that knows how to free the memory in type
-     *             specific instance of this class.
-     */
-    CallbackHolder(CallbackFunc callback, 
-                   CloneFunc clone,
-                   KillFunc kill):
-        m_callback(callback),
-        m_kill(kill),
-        m_clone(clone) { }
-
-    ~CallbackHolder() {
-        (*m_kill)(this);
-    }
-
-    /// @return a clone of this instance
-    CallbackHolder* clone() {
-        return (*m_clone)(this);
-    }
-
-    /// \c Callback to \c Functor specific callback
-    CallbackFunc m_callback;
-    
-protected:
-
-    CallbackHolder& operator = (const CallbackHolder& other) {
-        if ( this == &other ) {
-            return *this;
-        }
-        m_callback = other.m_callback;
-        m_clone = other.m_clone;
-        m_kill = other.m_kill;
-
-        return *this;
-    }
-
-    CallbackHolder(const CallbackHolder& other) {
-        *this = other;
-    }
-
-private:
-    /// This function is called to kill this instance
-    KillFunc m_kill;
-    /// Functions that knows how to clone a specific \c Functor type
-    CloneFunc m_clone;
+    virtual ~SlotBase() {}
 };
 
-
-/// Holds the functor and creates a clone callback for \c Functor specific type
-template <typename Functor>
-class FunctorHolder: public CallbackHolder {
+template<typename ReturnType>
+class SlotBase0: public SlotBase {
 public:
-    /// This type.
-    typedef FunctorHolder<Functor> Self;
-    /**
-     * @param functor The functor to be used when a signal is emitted.
-     * @param callback The callback to call when a signal is emitted.
-     */
-    FunctorHolder(const Functor& functor, CallbackFunc callback):
-        CallbackHolder(callback, &clone, &kill),
-        m_functor(functor) {
-    }
-
-    /// Specific clone for this Functor type
-    static CallbackHolder* clone(CallbackHolder* self) {
-        return new Self( static_cast<Self&>(*self));
-    }
-
-    static void kill(CallbackHolder* self) {
-        // Destroy functor
-        static_cast<Self*>( self )->m_functor.~Functor();
-    }
-
-    Functor m_functor; ///< the functor to use when a signal is emitted.
-};
-
-
-
-/// Callback with no arguments.
-template <typename Functor, typename ReturnType >
-struct Callback0 {
-    static ReturnType callback(CallbackHolder* base) {
-        static_cast< FunctorHolder<Functor>* >( base )->m_functor();
-        return ReturnType();
-    }
-
-    static CallbackFunc functionAddress() { 
-        return reinterpret_cast<CallbackFunc>(&callback);
-    }
+    virtual ReturnType operator()() = 0;
 };
 
-/// Callback with one argument
-template <typename Functor, typename ReturnType, typename Arg1>
-struct Callback1 {
-    typedef ReturnType (Functor::* CallbackType)(CallbackHolder*, Arg1);
-
-    static ReturnType callback(CallbackHolder* base, Arg1 arg1) {
-        static_cast< FunctorHolder<Functor>* >( base )->m_functor(arg1);
-        return ReturnType();
-    }
-
-    static CallbackFunc functionAddress() { 
-        return reinterpret_cast<CallbackFunc>(&callback);
-    }
-};
-
-/// Callback with two arguments
-template <typename Functor, typename ReturnType,
-          typename Arg1, typename Arg2>
-struct Callback2 {
-    typedef ReturnType (Functor::* CallbackType)(CallbackHolder*, Arg1, Arg2);
+template<typename ReturnType, typename Functor>
+class Slot0: public SlotBase0<ReturnType> {
+public:
+    virtual ReturnType operator()() { return m_functor(); }
 
-    static ReturnType callback(CallbackHolder* base, Arg1 arg1, Arg2 arg2) {
-        static_cast< FunctorHolder<Functor>* >( base )->m_functor(arg1, arg2);
-        return ReturnType();
-    }
+    Slot0(Functor functor) : m_functor(functor) {}
 
-    static CallbackFunc functionAddress() { 
-        return reinterpret_cast<CallbackFunc>(&callback);
-    }
+private:
+    Functor m_functor;
 };
 
-/// Callback with three arguments
-template <typename Functor, typename ReturnType,
-          typename Arg1, typename Arg2, typename Arg3>
-struct Callback3 {
-    typedef ReturnType (Functor::* CallbackType)(CallbackHolder*, Arg1, Arg2, Arg3);
-
-    static ReturnType callback(CallbackHolder* base, Arg1 arg1, Arg2 arg2, Arg3 arg3) {
-        static_cast< FunctorHolder<Functor>* >( base )->m_functor( arg1, arg2, arg3 );
-        return ReturnType();
-    }
-
-    static CallbackFunc functionAddress() { 
-        return reinterpret_cast<CallbackFunc>(&callback);
-    }
+template<typename ReturnType, typename Arg1>
+class SlotBase1: public SlotBase {
+public:
+    virtual ReturnType operator()(Arg1) = 0;
 };
 
-/// Holds callback holder and handles the copying of callback holders for the
-/// \c Slots.
-class SlotHolder {
+template<typename ReturnType, typename Arg1, typename Functor>
+class Slot1: public SlotBase1<ReturnType, Arg1> {
 public:
-    SlotHolder(const SlotHolder& other):
-        m_holder( other.m_holder ? other.m_holder->clone() : 0 ) {
-    }
-
-    ~SlotHolder() {
-        delete m_holder;
-    }
-
-    SlotHolder& operator = (const SlotHolder& other) {
-        if ( &other == this ) {
-            return *this;
-        }
-        delete m_holder;
-        if ( other.m_holder ) {
-            m_holder = other.m_holder->clone();
-        } else {
-            m_holder = 0;
-        }
-        return *this;
-    }
+    virtual ReturnType operator()(Arg1 arg1) { return m_functor(arg1); }
 
-    SlotHolder():m_holder( 0 ) { }
+    Slot1(Functor functor) : m_functor(functor) {}
 
-protected:
-    explicit SlotHolder(CallbackHolder* holder):
-        m_holder( holder ) {
-    }
-
-    CallbackHolder* m_holder;
+private:
+    Functor m_functor;
 };
 
-/// Slot with no argument.
-template <typename ReturnType>
-class Slot0: public SlotHolder {
+template<typename ReturnType, typename Arg1, typename Arg2>
+class SlotBase2: public SlotBase {
 public:
-    typedef ReturnType (*CallbackType)(CallbackHolder*);
-
-    template <typename Functor>
-    Slot0( const Functor& functor ):
-        SlotHolder( new FunctorHolder<Functor>
-                    (functor, Callback0<Functor, ReturnType>::functionAddress())) {
-    }
-
-    void operator()() {
-        if (m_holder)
-            reinterpret_cast<CallbackType>(m_holder->m_callback)( m_holder );
-    }
+    virtual ReturnType operator()(Arg1, Arg2) = 0;
 };
 
-/// Slot with one argument.
-template <typename ReturnType, typename Arg1>
-class Slot1:public SlotHolder {
+template<typename ReturnType, typename Arg1, typename Arg2, typename Functor>
+class Slot2: public SlotBase2<ReturnType, Arg1, Arg2> {
 public:
-    typedef ReturnType (*CallbackType)(CallbackHolder*, Arg1);
-
-    template <typename Functor>
-    Slot1( const Functor& functor ):
-        SlotHolder( new FunctorHolder<Functor>
-                    (functor, Callback1<Functor, ReturnType, Arg1>::functionAddress())){
-        
-    }
+    virtual ReturnType operator()(Arg1 arg1, Arg2 arg2) { return m_functor(arg1, arg2); }
 
-    void operator()(Arg1 arg) {
-        if (m_holder)
-            reinterpret_cast<CallbackType>(m_holder->m_callback)(m_holder, arg);
-    }
+    Slot2(Functor functor) : m_functor(functor) {}
 
+private:
+    Functor m_functor;
 };
 
-/// Slot with two arguments
-template <typename ReturnType, typename Arg1, typename Arg2>
-class Slot2: public SlotHolder {
+template<typename ReturnType, typename Arg1, typename Arg2, typename Arg3>
+class SlotBase3: public SlotBase {
 public:
-    typedef ReturnType (*CallbackType)(CallbackHolder*, Arg1, Arg2);
-    template <typename Functor>
-    Slot2( const Functor& functor ):
-        SlotHolder( new FunctorHolder<Functor>
-                    (functor, Callback2<Functor, ReturnType, Arg1, Arg2>::functionAddress())){
-        
-    }
-
-    void operator()(Arg1 arg1, Arg2 arg2) {
-        if (m_holder)
-            reinterpret_cast<CallbackType>(m_holder->m_callback)(m_holder, arg1, arg2);
-    }
+    virtual ReturnType operator()(Arg1, Arg2, Arg3) = 0;
+    virtual ~SlotBase3() {}
 };
 
-/// Slot with three arguments
-template <typename ReturnType, typename Arg1, typename Arg2, typename Arg3>
-class Slot3: public SlotHolder {
+template<typename ReturnType, typename Arg1, typename Arg2, typename Arg3, typename Functor>
+class Slot3: public SlotBase3<ReturnType, Arg1, Arg2, Arg3> {
 public:
-    typedef ReturnType (*CallbackType)(CallbackHolder*, Arg1, Arg2, Arg3);
-    template <typename Functor>
-    Slot3( const Functor& functor ):
-        SlotHolder( new FunctorHolder<Functor>
-                    (functor, Callback3<Functor, ReturnType, Arg1, Arg2, Arg3>::functionAddress())){
-        
-    }
+    virtual ReturnType operator()(Arg1 arg1, Arg2 arg2, Arg3 arg3)
+    { return m_functor(arg1, arg2, arg3); }
 
-    void operator()(Arg1 arg1, Arg2 arg2, Arg3 arg3) {
-        if (m_holder)
-            reinterpret_cast<CallbackType>(m_holder->m_callback)
-                ( m_holder, arg1, arg2, arg3 );
-    }
+    Slot3(Functor functor) : m_functor(functor) {}
+
+private:
+    Functor m_functor;
 };
 
 } // namespace SigImpl
-- 
cgit v0.11.2