b1db61e1fd
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@52746 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
123 lines
3.4 KiB
C++
123 lines
3.4 KiB
C++
/////////////////////////////////////////////////////////////////////////////
|
|
// Name: weakref.h
|
|
// Purpose: interface of wxWeakRefDynamic<T>
|
|
// Author: wxWidgets team
|
|
// RCS-ID: $Id$
|
|
// Licence: wxWindows license
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
|
|
/**
|
|
@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:
|
|
|
|
};
|
|
|
|
|
|
|
|
/**
|
|
@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}
|
|
|
|
@see 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() const;
|
|
|
|
/**
|
|
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*() const;
|
|
|
|
/**
|
|
Returns a reference to the tracked object. If the internal pointer is @NULL
|
|
this method will cause an assert in debug mode.
|
|
*/
|
|
T operator*() const;
|
|
|
|
/**
|
|
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);
|
|
};
|
|
|