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Commit	Line	Data
	1	/////////////////////////////////////////////////////////////////////////////
	2	// Name: weakref.h
	3	// Purpose: interface of wxWeakRefDynamic<T>
	4	// Author: wxWidgets team
	5	// RCS-ID: $Id$
	6	// Licence: wxWindows license
	7	/////////////////////////////////////////////////////////////////////////////
	8
	9	/**
	10	@wxheader{weakref.h}
	11
	12	wxWeakRefDynamicT is a template class for weak references that is used in
	13	the same way as wxWeakRefT. The only difference is that wxWeakRefDynamic
	14	defaults to using @c dynamic_cast for establishing the object
	15	reference (while wxWeakRef defaults to @c static_cast).
	16
	17	So, wxWeakRef will detect a type mismatch during compile time and will
	18	have a little better run-time performance. The role of wxWeakRefDynamic
	19	is to handle objects which derived type one does not know.
	20
	21	@b Note: wxWeakRefT selects an implementation based on the static type
	22	of T. If T does not have wxTrackable statically, it defaults to to a mixed-
	23	mode operation, where it uses @c dynamic_cast as the last measure (if
	24	available from the compiler and enabled when building wxWidgets).
	25
	26	For general cases, wxWeakRefT is the better choice.
	27
	28	For API documentation, see: wxWeakRef
	29
	30	@library{wxcore}
	31	@category{FIXME}
	32	*/
	33	class wxWeakRefDynamic<T>
	34	{
	35	public:
	36
	37	};
	38
	39
	40
	41	/**
	42	@wxheader{weakref.h}
	43
	44	wxWeakRef is a template class for weak references to wxWidgets objects,
	45	such as wxEvtHandler, wxWindow and
	46	wxObject. A weak reference behaves much like an ordinary
	47	pointer, but when the object pointed is destroyed, the weak reference is
	48	automatically reset to a @NULL pointer.
	49
	50	wxWeakRefT can be used whenever one must keep a pointer to an object
	51	that one does not directly own, and that may be destroyed before the object
	52	holding the reference.
	53
	54	wxWeakRefT is a small object and the mechanism behind it is fast
	55	(@b O(1)). So the overall cost of using it is small.
	56
	57	@library{wxbase}
	58	@category{FIXME}
	59
	60	@see wxSharedPtr, wxScopedPtr
	61	*/
	62	class wxWeakRef<T>
	63	{
	64	public:
	65	/**
	66	Constructor. The weak reference is initialized to @e pobj.
	67	*/
	68	wxWeakRefT(T* pobj = NULL);
	69
	70	/**
	71	Destructor.
	72	*/
	73	~wxWeakRefT();
	74
	75	/**
	76	Called when the tracked object is destroyed. Be default sets
	77	internal pointer to @NULL.
	78	*/
	79	virtual void OnObjectDestroy();
	80
	81	/**
	82	Release currently tracked object and rests object reference.
	83	*/
	84	void Release();
	85
	86	/**
	87	Returns pointer to the tracked object or @NULL.
	88	*/
	89	T* get() const;
	90
	91	/**
	92	Release currently tracked object and start tracking the same object as
	93	the wxWeakRef @e wr.
	94	*/
	95	T* operator =(wxWeakRef<T>& wr);
	96
	97	/**
	98	Implicit conversion to T*. Returns pointer to the tracked
	99	object or @NULL.
	100	*/
	101	T* operator*() const;
	102
	103	/**
	104	Returns a reference to the tracked object. If the internal pointer is @NULL
	105	this method will cause an assert in debug mode.
	106	*/
	107	T operator*() const;
	108
	109	/**
	110	Smart pointer member access. Returns a pointer to the
	111	tracked object. If the internal pointer is @NULL this
	112	method will cause an assert in debug mode.
	113	*/
	114	T* operator-();
	115
	116	/**
	117	Releases the currently tracked object and starts tracking @e pobj.
	118	A weak reference may be reset by passing @e @NULL as @e pobj.
	119	*/
	120	T* operator=(T* pobj);
	121	};
	122