X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/5a0c7d664e3f94655a6446b656eb77d9769a32df..8e77fd8bca165aab9709649d79a7cbc6a172d4e1:/include/wx/weakref.h?ds=sidebyside diff --git a/include/wx/weakref.h b/include/wx/weakref.h index 9ae506798b..e612db81b2 100644 --- a/include/wx/weakref.h +++ b/include/wx/weakref.h @@ -13,6 +13,23 @@ #include "wx/tracker.h" + +// Some compilers (VC6, Borland, g++ < 3.3) have problem with template specialization. +// However, this is only used for optimization purposes (a smaller wxWeakRef pointer) +// (and the corner case of wxWeakRef). So for those compilers, we can fall +// back to the non-optimal case, where we use the same type of weak ref (static one) +// in all cases. See defs.h for various setting these defines depending on compiler. + +#if !defined(HAVE_PARTIAL_SPECIALIZATION) || \ + !defined(HAVE_TEMPLATE_OVERLOAD_RESOLUTION) || \ + (defined(__GNUC__) && !wxCHECK_GCC_VERSION(3, 3)) + #define USE_ONLY_STATIC_WEAKREF +#endif + + +#ifndef USE_ONLY_STATIC_WEAKREF + +// Avoid including this for simpler compilers #include "wx/meta/convertible.h" #include "wx/meta/int2type.h" @@ -22,6 +39,9 @@ struct wxIsStaticTrackable enum { value = wxConvertibleTo::value }; }; +#endif // !USE_ONLY_STATIC_WEAKREF + + // Weak ref implementation when T has wxTrackable as a known base class template class wxWeakRefStatic : public wxTrackerNode @@ -41,6 +61,13 @@ public: } } + virtual void OnObjectDestroy() + { + // Tracked object itself removes us from list of trackers + wxASSERT(m_pobj != NULL); + m_pobj = NULL; + } + protected: void Assign(T* pobj) { @@ -64,17 +91,12 @@ protected: Assign( wr.m_pobj ); } - virtual void OnObjectDestroy() - { - // Tracked object itself removes us from list of trackers - wxASSERT( m_pobj!=NULL ); - m_pobj = NULL; - } - T *m_pobj; }; -#ifdef HAVE_PARTIAL_SPECIALIZATION + + +#ifndef USE_ONLY_STATIC_WEAKREF template struct wxWeakRefImpl; @@ -102,6 +124,14 @@ struct wxWeakRefImpl : public wxTrackerNode } } + virtual void OnObjectDestroy() + { + // Tracked object itself removes us from list of trackers + wxASSERT(m_pobj != NULL); + m_pobj = NULL; + m_ptbase = NULL; + } + protected: wxWeakRefImpl() : m_pobj(NULL), m_ptbase(NULL) { } @@ -119,7 +149,7 @@ protected: DoAssign( pobj, ptbase ); } -#ifdef HAVE_DYNAMIC_CAST +#ifndef wxNO_RTTI void AssignHelper(T* pobj, wxInt2Type) { // A last way to get a trackable pointer @@ -135,7 +165,7 @@ protected: Release(); } } -#endif // HAVE_DYNAMIC_CAST +#endif // RTTI enabled void AssignCopy(const wxWeakRefImpl& wr) { @@ -157,67 +187,75 @@ protected: } } - virtual void OnObjectDestroy() - { - // Tracked object itself removes us from list of trackers - wxASSERT( m_pobj!=NULL ); - m_pobj = NULL; - m_ptbase = NULL; - } - T *m_pobj; wxTrackable *m_ptbase; }; -#endif // HAVE_PARTIAL_SPECIALIZATION +#endif // #ifndef USE_ONLY_STATIC_WEAKREF -// A weak reference to an object of type T, where T has type wxTrackable + +// A weak reference to an object of type T, where T has base wxTrackable // (usually statically but if not dynamic_cast<> is tried). template class wxWeakRef : public -#ifdef HAVE_PARTIAL_SPECIALIZATION - wxWeakRefImpl::value> -#else +#ifdef USE_ONLY_STATIC_WEAKREF wxWeakRefStatic +#else + wxWeakRefImpl::value != 0> #endif { public: + typedef T element_type; + // Default ctor wxWeakRef() { } + // Enabling this ctor for VC6 results in mysterious compilation failures in + // wx/window.h when assigning wxWindow pointers (FIXME-VC6) +#ifndef __VISUALC6__ + // Ctor from the object of this type: this is needed as the template ctor + // below is not used by at least g++4 when a literal NULL is used + wxWeakRef(T *pobj) + { + this->Assign(pobj); + } +#endif // !__VISUALC6__ + // When we have the full type here, static_cast<> will always work // (or give a straight compiler error). template wxWeakRef(TDerived* pobj) { - Assign(pobj); + this->Assign(pobj); } - template - wxWeakRef& operator=(TDerived* pobj) + // We need this copy ctor, since otherwise a default compiler (binary) copy + // happens (if embedded as an object member). + wxWeakRef(const wxWeakRef& wr) { - Assign(pobj); - return *this; + this->Assign(wr.get()); } wxWeakRef& operator=(const wxWeakRef& wr) { - AssignCopy(wr); + this->AssignCopy(wr); return *this; } virtual ~wxWeakRef() { this->Release(); } // Smart pointer functions - T& operator*() const { return *this->m_pobj; } - T* operator->() const { return this->m_pobj; } + T& operator*() const { return *this->m_pobj; } + T* operator->() const { return this->m_pobj; } - T* get() const { return this->m_pobj; } - operator T*() const { return get(); } + T* get() const { return this->m_pobj; } + operator T*() const { return this->m_pobj; } }; +#ifndef wxNO_RTTI + // Weak ref implementation assign objects are queried for wxTrackable // using dynamic_cast<> template @@ -231,27 +269,24 @@ public: Assign(pobj); } + wxWeakRefDynamic(const wxWeakRef& wr) + { + Assign(wr.get()); + } + virtual ~wxWeakRefDynamic() { Release(); } // Smart pointer functions - T& operator * (){ wxASSERT(this->m_pobj); return *m_pobj; } - T* operator -> (){ wxASSERT(this->m_pobj); return m_pobj; } - T* operator = (T* pobj) { Assign(pobj); return m_pobj; } + T& operator*() const { wxASSERT(m_pobj); return *m_pobj; } + T* operator->() const { wxASSERT(m_pobj); return m_pobj; } - T* get(){ return this->m_pobj; } + T* get() const { return m_pobj; } + operator T* () const { return m_pobj; } - // operator T* (){ return this->m_pobj; } - - // test for pointer validity: defining conversion to unspecified_bool_type - // and not more obvious bool to avoid implicit conversions to integer types - typedef T *(wxWeakRef::*unspecified_bool_type)() const; - operator unspecified_bool_type() const - { - return m_pobj ? &wxWeakRef::get : NULL; - } + T* operator = (T* pobj) { Assign(pobj); return m_pobj; } // Assign from another weak ref, point to same object - T* operator = (const wxWeakRef &wr) { Assign( wr.get() ); return this->m_pobj; } + T* operator = (const wxWeakRef &wr) { Assign( wr.get() ); return m_pobj; } void Release() { @@ -266,6 +301,13 @@ public: } } + virtual void OnObjectDestroy() + { + wxASSERT_MSG(m_pobj, "tracked object should have removed us itself"); + + m_pobj = NULL; + } + protected: void Assign(T *pobj) { @@ -293,20 +335,17 @@ protected: } } - virtual void OnObjectDestroy() - { - wxASSERT_MSG( m_pobj, "tracked object should have removed us itself" ); - - m_pobj = NULL; - } - T *m_pobj; }; +#endif // RTTI enabled + + // Provide some basic types of weak references class WXDLLIMPEXP_FWD_BASE wxEvtHandler; class WXDLLIMPEXP_FWD_CORE wxWindow; + typedef wxWeakRef wxEvtHandlerRef; typedef wxWeakRef wxWindowRef;