pcsx2/3rdparty/wxwidgets3.0/include/wx/weakref.h

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/////////////////////////////////////////////////////////////////////////////
// Name: wx/weakref.h
// Purpose: wxWeakRef - Generic weak references for wxWidgets
// Author: Arne Steinarson
// Created: 27 Dec 07
// Copyright: (c) 2007 Arne Steinarson
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_WEAKREF_H_
#define _WX_WEAKREF_H_
#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<wxObject>). 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"
template <class T>
struct wxIsStaticTrackable
{
enum { value = wxConvertibleTo<T, wxTrackable>::value };
};
#endif // !USE_ONLY_STATIC_WEAKREF
// Weak ref implementation when T has wxTrackable as a known base class
template <class T>
class wxWeakRefStatic : public wxTrackerNode
{
public:
wxWeakRefStatic() : m_pobj(NULL) { }
void Release()
{
// Release old object if any
if ( m_pobj )
{
// Remove ourselves from object tracker list
wxTrackable *pt = static_cast<wxTrackable*>(m_pobj);
pt->RemoveNode(this);
m_pobj = NULL;
}
}
virtual void OnObjectDestroy()
{
// Tracked object itself removes us from list of trackers
wxASSERT(m_pobj != NULL);
m_pobj = NULL;
}
protected:
void Assign(T* pobj)
{
if ( m_pobj == pobj )
return;
Release();
// Now set new trackable object
if ( pobj )
{
// Add ourselves to object tracker list
wxTrackable *pt = static_cast<wxTrackable*>(pobj);
pt->AddNode(this);
m_pobj = pobj;
}
}
void AssignCopy(const wxWeakRefStatic& wr)
{
Assign( wr.m_pobj );
}
T *m_pobj;
};
#ifndef USE_ONLY_STATIC_WEAKREF
template<class T,bool use_static>
struct wxWeakRefImpl;
// Intermediate class, to select the static case above.
template <class T>
struct wxWeakRefImpl<T, true> : public wxWeakRefStatic<T>
{
enum { value = 1 };
};
// Weak ref implementation when T does not have wxTrackable as known base class
template<class T>
struct wxWeakRefImpl<T, false> : public wxTrackerNode
{
void Release()
{
// Release old object if any
if ( m_pobj )
{
// Remove ourselves from object tracker list
m_ptbase->RemoveNode(this);
m_pobj = NULL;
m_ptbase = NULL;
}
}
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) { }
// Assign receives most derived class here and can use that
template <class TDerived>
void Assign( TDerived* pobj )
{
AssignHelper( pobj, wxInt2Type<wxIsStaticTrackable<TDerived>::value>() );
}
template <class TDerived>
void AssignHelper(TDerived* pobj, wxInt2Type<true>)
{
wxTrackable *ptbase = static_cast<wxTrackable*>(pobj);
DoAssign( pobj, ptbase );
}
#ifndef wxNO_RTTI
void AssignHelper(T* pobj, wxInt2Type<false>)
{
// A last way to get a trackable pointer
wxTrackable *ptbase = dynamic_cast<wxTrackable*>(pobj);
if ( ptbase )
{
DoAssign( pobj, ptbase );
}
else
{
wxFAIL_MSG( "Tracked class should inherit from wxTrackable" );
Release();
}
}
#endif // RTTI enabled
void AssignCopy(const wxWeakRefImpl& wr)
{
DoAssign(wr.m_pobj, wr.m_ptbase);
}
void DoAssign( T* pobj, wxTrackable *ptbase ) {
if( m_pobj==pobj ) return;
Release();
// Now set new trackable object
if( pobj )
{
// Add ourselves to object tracker list
wxASSERT( ptbase );
ptbase->AddNode( this );
m_pobj = pobj;
m_ptbase = ptbase;
}
}
T *m_pobj;
wxTrackable *m_ptbase;
};
#endif // #ifndef USE_ONLY_STATIC_WEAKREF
// 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 T>
class wxWeakRef : public
#ifdef USE_ONLY_STATIC_WEAKREF
wxWeakRefStatic<T>
#else
wxWeakRefImpl<T, wxIsStaticTrackable<T>::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 <class TDerived>
wxWeakRef(TDerived* pobj)
{
this->Assign(pobj);
}
// We need this copy ctor, since otherwise a default compiler (binary) copy
// happens (if embedded as an object member).
wxWeakRef(const wxWeakRef<T>& wr)
{
this->Assign(wr.get());
}
wxWeakRef<T>& operator=(const wxWeakRef<T>& 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* 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 <class T>
class wxWeakRefDynamic : public wxTrackerNode
{
public:
wxWeakRefDynamic() : m_pobj(NULL) { }
wxWeakRefDynamic(T* pobj) : m_pobj(pobj)
{
Assign(pobj);
}
wxWeakRefDynamic(const wxWeakRef<T>& wr)
{
Assign(wr.get());
}
virtual ~wxWeakRefDynamic() { Release(); }
// Smart pointer functions
T& operator*() const { wxASSERT(m_pobj); return *m_pobj; }
T* operator->() const { wxASSERT(m_pobj); return m_pobj; }
T* get() const { return m_pobj; }
operator T* () const { return m_pobj; }
T* operator = (T* pobj) { Assign(pobj); return m_pobj; }
// Assign from another weak ref, point to same object
T* operator = (const wxWeakRef<T> &wr) { Assign( wr.get() ); return m_pobj; }
void Release()
{
// Release old object if any
if( m_pobj )
{
// Remove ourselves from object tracker list
wxTrackable *pt = dynamic_cast<wxTrackable*>(m_pobj);
wxASSERT(pt);
pt->RemoveNode(this);
m_pobj = NULL;
}
}
virtual void OnObjectDestroy()
{
wxASSERT_MSG(m_pobj, "tracked object should have removed us itself");
m_pobj = NULL;
}
protected:
void Assign(T *pobj)
{
if ( m_pobj == pobj )
return;
Release();
// Now set new trackable object
if ( pobj )
{
// Add ourselves to object tracker list
wxTrackable *pt = dynamic_cast<wxTrackable*>(pobj);
if ( pt )
{
pt->AddNode(this);
m_pobj = pobj;
}
else
{
// If the object we want to track does not support wxTackable, then
// log a message and keep the NULL object pointer.
wxFAIL_MSG( "Tracked class should inherit from wxTrackable" );
}
}
}
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<wxEvtHandler> wxEvtHandlerRef;
typedef wxWeakRef<wxWindow> wxWindowRef;
#endif // _WX_WEAKREF_H_