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1 | ///////////////////////////////////////////////////////////////////////////// |
2 | // Name: wx/mac/corefoundation/cfref.h | |
3 | // Purpose: wxCFRef template class | |
4 | // Author: David Elliott <dfe@cox.net> | |
5 | // Modified by: Stefan Csomor | |
6 | // Created: 2007/05/10 | |
7 | // RCS-ID: $Id$ | |
8 | // Copyright: (c) 2007 David Elliott <dfe@cox.net>, Stefan Csomor | |
9 | // Licence: wxWindows licence | |
10 | // Notes: See http://developer.apple.com/documentation/CoreFoundation/Conceptual/CFMemoryMgmt/index.html | |
11 | ///////////////////////////////////////////////////////////////////////////// | |
12 | /*! @header wx/mac/corefoundation/cfref.h | |
13 | @abstract wxCFRef template class | |
14 | @discussion FIXME: Convert doc tags to something less buggy with C++ | |
15 | */ | |
16 | ||
17 | #ifndef _WX_MAC_COREFOUNDATION_CFREF_H__ | |
18 | #define _WX_MAC_COREFOUNDATION_CFREF_H__ | |
19 | ||
20 | // Include unistd to ensure that NULL is defined | |
21 | #include <unistd.h> | |
22 | // Include AvailabilityMacros for DEPRECATED_ATTRIBUTE | |
23 | #include <AvailabilityMacros.h> | |
24 | ||
25 | // #include <CoreFoundation/CFBase.h> | |
26 | /* Don't include CFBase.h such that this header can be included from public | |
27 | * headers with minimal namespace pollution. | |
28 | * Note that Darwin CF uses extern for CF_EXPORT. If we need this on Win32 | |
29 | * or non-Darwin Mac OS we'll need to define the appropriate __declspec. | |
30 | */ | |
31 | typedef const void *CFTypeRef; | |
32 | extern "C" { | |
33 | extern /* CF_EXPORT */ | |
34 | CFTypeRef CFRetain(CFTypeRef cf); | |
35 | extern /* CF_EXPORT */ | |
36 | void CFRelease(CFTypeRef cf); | |
37 | } // extern "C" | |
38 | ||
39 | ||
40 | /*! @function wxCFRelease | |
41 | @abstract A CFRelease variant that checks for NULL before releasing. | |
42 | @discussion The parameter is template not for type safety but to ensure the argument | |
43 | is a raw pointer and not a ref holder of any type. | |
44 | */ | |
45 | template <class Type> | |
46 | inline void wxCFRelease(Type *r) | |
47 | { | |
48 | if ( r != NULL ) | |
49 | ::CFRelease((CFTypeRef)r); | |
50 | } | |
51 | ||
52 | /*! @function wxCFRetain | |
53 | @abstract A typesafe CFRetain variant that checks for NULL. | |
54 | */ | |
55 | template <class Type> | |
56 | inline Type* wxCFRetain(Type *r) | |
57 | { | |
58 | // NOTE(DE): Setting r to the result of CFRetain improves efficiency on both x86 and PPC | |
59 | // Casting r to CFTypeRef ensures we are calling the real C version defined in CFBase.h | |
60 | // and not any possibly templated/overloaded CFRetain. | |
61 | if ( r != NULL ) | |
62 | r = (Type*)::CFRetain((CFTypeRef)r); | |
63 | return r; | |
64 | } | |
65 | ||
66 | template <class refType> | |
67 | class wxCFRef; | |
68 | ||
69 | /*! @class wxCFWeakRef | |
70 | @templatefield refType The CF reference type (e.g. CFStringRef, CFRunLoopRef, etc.) | |
71 | It should already be a pointer. This is different from | |
72 | shared_ptr where the template parameter is the pointee type. | |
73 | @discussion Wraps a raw pointer without any retain or release. | |
74 | Provides a way to get what amounts to a raw pointer from a wxCFRef without | |
75 | using a raw pointer. Unlike a raw pointer, constructing a wxCFRef from this | |
76 | class will cause it to be retained because it is assumed that a wxCFWeakRef | |
77 | does not own its pointer. | |
78 | */ | |
79 | template <class refType> | |
80 | class wxCFWeakRef | |
81 | { | |
82 | template <class refTypeA, class otherRefType> | |
83 | friend wxCFWeakRef<refTypeA> static_cfref_cast(const wxCFRef<otherRefType> &otherRef); | |
84 | public: | |
85 | /*! @method wxCFWeakRef | |
86 | @abstract Creates a NULL reference | |
87 | */ | |
88 | wxCFWeakRef() | |
89 | : m_ptr(NULL) | |
90 | {} | |
91 | ||
92 | // Default copy constructor is fine. | |
93 | // Default destructor is fine but we'll set NULL to avoid bugs | |
94 | ~wxCFWeakRef() | |
95 | { m_ptr = NULL; } | |
96 | ||
97 | // Do not implement a raw-pointer constructor. | |
98 | ||
99 | /*! @method wxCFWeakRef | |
100 | @abstract Copies another ref holder where its type can be converted to ours | |
101 | @templatefield otherRefType Any type held by another wxCFWeakRef. | |
102 | @param otherRef The other weak ref holder to copy. | |
103 | @discussion This is merely a copy or implicit cast. | |
104 | */ | |
105 | template <class otherRefType> | |
106 | wxCFWeakRef(const wxCFWeakRef<otherRefType>& otherRef) | |
107 | : m_ptr(otherRef.get()) // Implicit conversion from otherRefType to refType should occur | |
108 | {} | |
109 | ||
110 | /*! @method wxCFWeakRef | |
111 | @abstract Copies a strong ref holder where its type can be converted to ours | |
112 | @templatefield otherRefType Any type held by a wxCFRef. | |
113 | @param otherRef The strong ref holder to copy. | |
114 | @discussion This ref is merely a pointer copy, the strong ref still holds the pointer. | |
115 | */ | |
116 | template <class otherRefType> | |
117 | wxCFWeakRef(const wxCFRef<otherRefType>& otherRef) | |
118 | : m_ptr(otherRef.get()) // Implicit conversion from otherRefType to refType should occur | |
119 | {} | |
120 | ||
121 | /*! @method get | |
122 | @abstract Explicit conversion to the underlying pointer type | |
123 | @discussion Allows the caller to explicitly get the underlying pointer. | |
124 | */ | |
125 | refType get() const | |
126 | { return m_ptr; } | |
127 | ||
128 | /*! @method operator refType | |
129 | @abstract Implicit conversion to the underlying pointer type | |
130 | @discussion Allows the ref to be used in CF function calls. | |
131 | */ | |
132 | operator refType() const | |
133 | { return m_ptr; } | |
134 | ||
135 | protected: | |
136 | /*! @method wxCFWeakRef | |
137 | @abstract Constructs a weak reference to the raw pointer | |
138 | @templatefield otherType Any type. | |
139 | @param p The raw pointer to assume ownership of. May be NULL. | |
140 | @discussion This method is private so that the friend static_cfref_cast can use it | |
141 | */ | |
142 | template <class otherType> | |
143 | explicit wxCFWeakRef(otherType *p) | |
144 | : m_ptr(p) // Implicit conversion from otherType* to refType should occur. | |
145 | {} | |
146 | ||
147 | /*! @var m_ptr The raw pointer. | |
148 | */ | |
149 | refType m_ptr; | |
150 | }; | |
151 | ||
152 | /*! @class wxCFRef | |
153 | @templatefield refType The CF reference type (e.g. CFStringRef, CFRunLoopRef, etc.) | |
154 | It should already be a pointer. This is different from | |
155 | shared_ptr where the template parameter is the pointee type. | |
156 | @discussion Properly retains/releases reference to CoreFoundation objects | |
157 | */ | |
158 | template <class refType> | |
159 | class wxCFRef | |
160 | { | |
161 | public: | |
162 | /*! @method wxCFRef | |
163 | @abstract Creates a NULL reference | |
164 | */ | |
165 | wxCFRef() | |
166 | : m_ptr(NULL) | |
167 | {} | |
168 | ||
169 | /*! @method wxCFRef | |
170 | @abstract Assumes ownership of p and creates a reference to it. | |
171 | @templatefield otherType Any type. | |
172 | @param p The raw pointer to assume ownership of. May be NULL. | |
173 | @discussion Like shared_ptr, it is assumed that the caller has a strong reference to p and intends | |
174 | to transfer ownership of that reference to this ref holder. If the object comes from | |
175 | a Create or Copy method then this is the correct behavior. If the object comes from | |
176 | a Get method then you must CFRetain it yourself before passing it to this constructor. | |
177 | A handy way to do this is to use the non-member wxCFRefFromGet factory funcion. | |
178 | This method is templated and takes an otherType *p. This prevents implicit conversion | |
179 | using an operator refType() in a different ref-holding class type. | |
180 | */ | |
181 | template <class otherType> | |
182 | explicit wxCFRef(otherType *p) | |
183 | : m_ptr(p) // Implicit conversion from otherType* to refType should occur. | |
184 | {} | |
185 | ||
186 | /*! @method wxCFRef | |
187 | @abstract Copies a ref holder of the same type | |
188 | @param otherRef The other ref holder to copy. | |
189 | @discussion Ownership will be shared by the original ref and the newly created ref. That is, | |
190 | the object will be explicitly retained by this new ref. | |
191 | */ | |
192 | wxCFRef(const wxCFRef& otherRef) | |
193 | : m_ptr(wxCFRetain(otherRef.m_ptr)) | |
194 | {} | |
195 | ||
196 | /*! @method wxCFRef | |
197 | @abstract Copies a ref holder where its type can be converted to ours | |
198 | @templatefield otherRefType Any type held by another wxCFRef. | |
199 | @param otherRef The other ref holder to copy. | |
200 | @discussion Ownership will be shared by the original ref and the newly created ref. That is, | |
201 | the object will be explicitly retained by this new ref. | |
202 | */ | |
203 | template <class otherRefType> | |
204 | wxCFRef(const wxCFRef<otherRefType>& otherRef) | |
205 | : m_ptr(wxCFRetain(otherRef.get())) // Implicit conversion from otherRefType to refType should occur | |
206 | {} | |
207 | ||
208 | /*! @method wxCFRef | |
209 | @abstract Copies a weak ref holder where its type can be converted to ours | |
210 | @templatefield otherRefType Any type held by a wxCFWeakRef. | |
211 | @param otherRef The weak ref holder to copy. | |
212 | @discussion Ownership will be taken by this newly created ref. That is, | |
213 | the object will be explicitly retained by this new ref. | |
214 | Ownership is most likely shared with some other ref as well. | |
215 | */ | |
216 | template <class otherRefType> | |
217 | wxCFRef(const wxCFWeakRef<otherRefType>& otherRef) | |
218 | : m_ptr(wxCFRetain(otherRef.get())) // Implicit conversion from otherRefType to refType should occur | |
219 | {} | |
220 | ||
221 | /*! @method ~wxCFRef | |
222 | @abstract Releases (potentially shared) ownership of the ref. | |
223 | @discussion A ref holder instance is always assumed to have ownership so ownership is always | |
224 | released (CFRelease called) upon destruction. | |
225 | */ | |
226 | ~wxCFRef() | |
227 | { reset(); } | |
228 | ||
229 | /*! @method operator= | |
230 | @abstract Assigns the other ref's pointer to us when the otherRef is the same type. | |
231 | @param otherRef The other ref holder to copy. | |
232 | @discussion The incoming pointer is retained, the original pointer is released, and this object | |
233 | is made to point to the new pointer. | |
234 | */ | |
235 | wxCFRef& operator=(const wxCFRef& otherRef) | |
236 | { | |
237 | wxCFRetain(otherRef.m_ptr); | |
238 | wxCFRelease(m_ptr); | |
239 | m_ptr = otherRef.m_ptr; | |
240 | return *this; | |
241 | } | |
242 | ||
243 | /*! @method operator= | |
244 | @abstract Assigns the other ref's pointer to us when the other ref can be converted to our type. | |
245 | @templatefield otherRefType Any type held by another wxCFRef | |
246 | @param otherRef The other ref holder to copy. | |
247 | @discussion The incoming pointer is retained, the original pointer is released, and this object | |
248 | is made to point to the new pointer. | |
249 | */ | |
250 | template <class otherRefType> | |
251 | wxCFRef& operator=(const wxCFRef<otherRefType>& otherRef) | |
252 | { | |
253 | wxCFRetain(otherRef.get()); | |
254 | wxCFRelease(m_ptr); | |
255 | m_ptr = otherRef.get(); // Implicit conversion from otherRefType to refType should occur | |
256 | return *this; | |
257 | } | |
258 | ||
259 | /*! @method get | |
260 | @abstract Explicit conversion to the underlying pointer type | |
261 | @discussion Allows the caller to explicitly get the underlying pointer. | |
262 | */ | |
263 | refType get() const | |
264 | { return m_ptr; } | |
265 | ||
266 | /*! @method operator refType | |
267 | @abstract Implicit conversion to the underlying pointer type | |
268 | @discussion Allows the ref to be used in CF function calls. | |
269 | */ | |
270 | operator refType() const | |
271 | { return m_ptr; } | |
272 | ||
273 | #if 0 | |
274 | < // HeaderDoc is retarded and thinks the GT from operator-> is part of a template param. | |
275 | // So give it that < outside of a comment to fake it out. (if 0 is not a comment to HeaderDoc) | |
276 | #endif | |
277 | ||
278 | /*! @method operator-> | |
279 | @abstract Implicit conversion to the underlying pointer type | |
280 | @discussion This is nearly useless for CF types which are nearly always opaque | |
281 | */ | |
282 | refType operator-> () const | |
283 | { return m_ptr; } | |
284 | ||
285 | /*! @method reset | |
286 | @abstract Nullifies the reference | |
287 | @discussion Releases ownership (calls CFRelease) before nullifying the pointer. | |
288 | */ | |
289 | void reset() | |
290 | { | |
291 | wxCFRelease(m_ptr); | |
292 | m_ptr = NULL; | |
293 | } | |
294 | ||
295 | /*! @method reset | |
296 | @abstract Sets this to a new reference | |
297 | @templatefield otherType Any type. | |
298 | @param p The raw pointer to assume ownership of | |
299 | @discussion The existing reference is released (like destruction). It is assumed that the caller | |
300 | has a strong reference to the new p and intends to transfer ownership of that reference | |
301 | to this ref holder. Take care to call CFRetain if you received the object from a Get method. | |
302 | This method is templated and takes an otherType *p. This prevents implicit conversion | |
303 | using an operator refType() in a different ref-holding class type. | |
304 | */ | |
305 | template <class otherType> | |
306 | void reset(otherType* p) | |
307 | { | |
308 | wxCFRelease(m_ptr); | |
309 | m_ptr = p; // Automatic conversion should occur | |
310 | } | |
311 | protected: | |
312 | /*! @var m_ptr The raw pointer. | |
313 | */ | |
314 | refType m_ptr; | |
315 | }; | |
316 | ||
317 | /*! @function wxCFRefFromGet | |
318 | @abstract Factory function to create wxCFRef from a raw pointer obtained from a Get-rule function | |
319 | @param p The pointer to retain and create a wxCFRef from. May be NULL. | |
320 | @discussion Unlike the wxCFRef raw pointer constructor, this function explicitly retains its | |
321 | argument. This can be used for functions such as CFDictionaryGetValue() or | |
322 | CFAttributedStringGetString() which return a temporary reference (Get-rule functions). | |
323 | FIXME: Anybody got a better name? | |
324 | */ | |
325 | template <typename Type> | |
326 | inline wxCFRef<Type*> wxCFRefFromGet(Type *p) | |
327 | { | |
328 | return wxCFRef<Type*>(wxCFRetain(p)); | |
329 | } | |
330 | ||
331 | /*! @function static_cfref_cast | |
332 | @abstract Works like static_cast but with a wxCFRef as the argument. | |
333 | @param refType Template parameter. The destination raw pointer type | |
334 | @param otherRef Normal parameter. The source wxCFRef<> object. | |
335 | @discussion This is intended to be a clever way to make static_cast work while allowing | |
336 | the return value to be converted to either a strong ref or a raw pointer | |
337 | while ensuring that the retain count is updated appropriately. | |
338 | ||
339 | This is modeled after shared_ptr's static_pointer_cast. Just as wxCFRef is | |
340 | parameterized on a pointer to an opaque type so is this class. Note that | |
341 | this differs from shared_ptr which is parameterized on the pointee type. | |
342 | ||
343 | FIXME: Anybody got a better name? | |
344 | */ | |
345 | template <class refType, class otherRefType> | |
346 | inline wxCFWeakRef<refType> static_cfref_cast(const wxCFRef<otherRefType> &otherRef); | |
347 | ||
348 | template <class refType, class otherRefType> | |
349 | inline wxCFWeakRef<refType> static_cfref_cast(const wxCFRef<otherRefType> &otherRef) | |
350 | { | |
351 | return wxCFWeakRef<refType>(static_cast<refType>(otherRef.get())); | |
352 | } | |
353 | ||
354 | /*! @function CFRelease | |
355 | @abstract Overloads CFRelease so that the user is warned of bad behavior. | |
356 | @discussion It is rarely appropriate to retain or release a wxCFRef. If one absolutely | |
357 | must do it he can explicitly get() the raw pointer | |
358 | Normally, this function is unimplemented resulting in a linker error if used. | |
359 | */ | |
360 | template <class T> | |
361 | inline void CFRelease(const wxCFRef<T*> & cfref) DEPRECATED_ATTRIBUTE; | |
362 | ||
363 | /*! @function CFRetain | |
364 | @abstract Overloads CFRetain so that the user is warned of bad behavior. | |
365 | @discussion It is rarely appropriate to retain or release a wxCFRef. If one absolutely | |
366 | must do it he can explicitly get() the raw pointer | |
367 | Normally, this function is unimplemented resulting in a linker error if used. | |
368 | */ | |
369 | template <class T> | |
370 | inline void CFRetain(const wxCFRef<T*>& cfref) DEPRECATED_ATTRIBUTE; | |
371 | ||
372 | // Change the 0 to a 1 if you want the functions to work (no link errors) | |
373 | // Neither function will cause retain/release side-effects if implemented. | |
374 | #if 0 | |
375 | template <class T> | |
376 | void CFRelease(const wxCFRef<T*> & cfref) | |
377 | { | |
378 | CFRelease(cfref.get()); | |
379 | } | |
380 | ||
381 | template <class T> | |
382 | void CFRetain(const wxCFRef<T*> & cfref) | |
383 | { | |
384 | CFRetain(cfref.get()); | |
385 | } | |
386 | #endif | |
387 | ||
388 | #endif //ndef _WX_MAC_COREFOUNDATION_CFREF_H__ | |
389 |