wxWidgets/interface/weakref.h
2008-03-08 13:52:38 +00:00

124 lines
3.5 KiB
Objective-C

/////////////////////////////////////////////////////////////////////////////
// Name: weakref.h
// Purpose: documentation for wxWeakRefDynamic<T> class
// Author: wxWidgets team
// RCS-ID: $Id$
// Licence: wxWindows license
/////////////////////////////////////////////////////////////////////////////
/**
@class wxWeakRefDynamicT
@wxheader{weakref.h}
wxWeakRefDynamicT is a template class for weak references that is used in
the same way as wxWeakRefT. The only difference is that wxWeakRefDynamic
defaults to using @c dynamic_cast for establishing the object
reference (while wxWeakRef defaults to @c static_cast).
So, wxWeakRef will detect a type mismatch during compile time and will
have a little better run-time performance. The role of wxWeakRefDynamic
is to handle objects which derived type one does not know.
@b Note: wxWeakRefT selects an implementation based on the static type
of T. If T does not have wxTrackable statically, it defaults to to a mixed-
mode operation, where it uses @c dynamic_cast as the last measure (if
available from the compiler and enabled when building wxWidgets).
For general cases, wxWeakRefT is the better choice.
For API documentation, see: wxWeakRef
@library{wxcore}
@category{FIXME}
*/
class wxWeakRefDynamic<T>
{
public:
};
/**
@class wxWeakRefT
@wxheader{weakref.h}
wxWeakRef is a template class for weak references to wxWidgets objects,
such as wxEvtHandler, wxWindow and
wxObject. A weak reference behaves much like an ordinary
pointer, but when the object pointed is destroyed, the weak reference is
automatically reset to a @NULL pointer.
wxWeakRefT can be used whenever one must keep a pointer to an object
that one does not directly own, and that may be destroyed before the object
holding the reference.
wxWeakRefT is a small object and the mechanism behind it is fast
(@b O(1)). So the overall cost of using it is small.
@library{wxbase}
@category{FIXME}
@seealso
wxSharedPtr, wxScopedPtr
*/
class wxWeakRef<T>
{
public:
/**
Constructor. The weak reference is initialized to @e pobj.
*/
wxWeakRefT(T* pobj = @NULL);
/**
Destructor.
*/
~wxWeakRefT();
/**
Called when the tracked object is destroyed. Be default sets
internal pointer to @NULL.
*/
virtual void OnObjectDestroy();
/**
Release currently tracked object and rests object reference.
*/
void Release();
/**
Returns pointer to the tracked object or @NULL.
*/
T * get();
/**
Release currently tracked object and start tracking the same object as
the wxWeakRef @e wr.
*/
T* operator =(wxWeakRef<T>& wr);
/**
Implicit conversion to T*. Returns pointer to the tracked
object or @NULL.
*/
T* operator*();
/**
Returns a reference to the tracked object. If the internal pointer is @NULL
this method will cause an assert in debug mode.
*/
T operator*();
/**
Smart pointer member access. Returns a pointer to the
tracked object. If the internal pointer is @NULL this
method will cause an assert in debug mode.
*/
T* operator-();
/**
Releases the currently tracked object and starts tracking @e pobj.
A weak reference may be reset by passing @e @NULL as @e pobj.
*/
T* operator=(T* pobj);
};