90 lines
2.3 KiB
C
90 lines
2.3 KiB
C
|
/////////////////////////////////////////////////////////////////////////////
|
||
|
|
// Name: wx/weakref.h
|
||
|
|
// Purpose: wxWeakRef - Generic weak references for wxWidgets
|
||
|
|
// Author: Arne Steinarson
|
||
|
|
// Created: 2007-12-27
|
||
|
|
// RCS-ID: $Id:$
|
||
|
|
// Copyright: (c) 2007 Arne Steinarson
|
||
|
|
// Licence: wxWindows licence
|
||
|
|
/////////////////////////////////////////////////////////////////////////////
|
||
|
|
|
||
|
|
#ifndef _WX_WEAKREF_H_
|
||
|
|
#define _WX_WEAKREF_H_
|
||
|
|
|
||
|
|
#include <wx/tracker.h>
|
||
|
|
|
||
|
|
// A weak reference to an object of type T, where T has type wxTrackable
|
||
|
|
// as one of its base classes (in a static or dynamic sense).
|
||
|
|
template<class T>
|
||
|
|
class wxWeakRef : public wxTrackerNode
|
||
|
|
{
|
||
|
|
public:
|
||
|
|
wxWeakRef(T *pobj = NULL) : m_pobj(NULL) { Assign(pobj); }
|
||
|
|
|
||
|
|
virtual ~wxWeakRef() { Assign(NULL); }
|
||
|
|
|
||
|
|
// Smart pointer functions
|
||
|
|
operator T*(){ return m_pobj; }
|
||
|
|
T* operator->(){ return m_pobj; }
|
||
|
|
T* operator=(T *pobj)
|
||
|
|
{
|
||
|
|
Assign(pobj);
|
||
|
|
return m_pobj;
|
||
|
|
}
|
||
|
|
|
||
|
|
virtual void OnObjectDestroy()
|
||
|
|
{
|
||
|
|
// Tracked object itself removes us from list of trackers
|
||
|
|
wxASSERT( m_pobj );
|
||
|
|
m_pobj = NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
virtual wxTrackerNodeType GetType() { return WeakRef; }
|
||
|
|
|
||
|
|
protected:
|
||
|
|
wxTrackableBase *GetTrackable(T *pobj)
|
||
|
|
{
|
||
|
|
// this uses static_cast if possible or dynamic_cast otherwise
|
||
|
|
return wxTrackableCaster<T, wxHasBase<T, wxTrackableBase>::value>
|
||
|
|
::Cast(pobj);
|
||
|
|
}
|
||
|
|
|
||
|
|
void Assign(T* pobj)
|
||
|
|
{
|
||
|
|
if ( m_pobj == pobj )
|
||
|
|
return;
|
||
|
|
|
||
|
|
// First release old object if any
|
||
|
|
if ( m_pobj )
|
||
|
|
{
|
||
|
|
// Remove ourselves from object tracker list
|
||
|
|
GetTrackable(m_pobj)->RemoveNode(this);
|
||
|
|
m_pobj = NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Now set new trackable object
|
||
|
|
if ( pobj )
|
||
|
|
{
|
||
|
|
wxTrackableBase * const pt = GetTrackable(pobj);
|
||
|
|
wxCHECK_RET( pt, "type must derive from wxTrackableBase" );
|
||
|
|
|
||
|
|
pt->AddNode(this);
|
||
|
|
m_pobj = pobj;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
T *m_pobj;
|
||
|
|
};
|
||
|
|
|
||
|
|
// Provide some basic types of weak references
|
||
|
|
class WXDLLIMPEXP_FWD_BASE wxObject;
|
||
|
|
class WXDLLIMPEXP_FWD_BASE wxEvtHandler;
|
||
|
|
class WXDLLIMPEXP_FWD_CORE wxWindow;
|
||
|
|
|
||
|
|
typedef wxWeakRef<wxObject> wxObjectRef;
|
||
|
|
typedef wxWeakRef<wxEvtHandler> wxEvtHandlerRef;
|
||
|
|
typedef wxWeakRef<wxWindow> wxWindowRef;
|
||
|
|
|
||
|
|
#endif // _WX_WEAKREF_H_
|
||
|
|
|