1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef BASE_MAC_SCOPED_CFTYPEREF_H_
6#define BASE_MAC_SCOPED_CFTYPEREF_H_
7
8#include <CoreFoundation/CoreFoundation.h>
9
10#include "base/mac/scoped_typeref.h"
11
12namespace base {
13
14// ScopedCFTypeRef<> is patterned after scoped_ptr<>, but maintains ownership
15// of a CoreFoundation object: any object that can be represented as a
16// CFTypeRef.  Style deviations here are solely for compatibility with
17// scoped_ptr<>'s interface, with which everyone is already familiar.
18//
19// By default, ScopedCFTypeRef<> takes ownership of an object (in the
20// constructor or in reset()) by taking over the caller's existing ownership
21// claim.  The caller must own the object it gives to ScopedCFTypeRef<>, and
22// relinquishes an ownership claim to that object.  ScopedCFTypeRef<> does not
23// call CFRetain(). This behavior is parameterized by the |OwnershipPolicy|
24// enum. If the value |RETAIN| is passed (in the constructor or in reset()),
25// then ScopedCFTypeRef<> will call CFRetain() on the object, and the initial
26// ownership is not changed.
27
28namespace internal {
29
30struct ScopedCFTypeRefTraits {
31  static void Retain(CFTypeRef object) {
32    CFRetain(object);
33  }
34  static void Release(CFTypeRef object) {
35    CFRelease(object);
36  }
37};
38
39}  // namespace internal
40
41template<typename CFT>
42class ScopedCFTypeRef
43    : public ScopedTypeRef<CFT, internal::ScopedCFTypeRefTraits> {
44 public:
45  typedef CFT element_type;
46
47  explicit ScopedCFTypeRef(
48      CFT object = NULL,
49      base::scoped_policy::OwnershipPolicy policy = base::scoped_policy::ASSUME)
50      : ScopedTypeRef<CFT,
51                      internal::ScopedCFTypeRefTraits>(object, policy) {}
52
53  ScopedCFTypeRef(const ScopedCFTypeRef<CFT>& that)
54      : ScopedTypeRef<CFT, internal::ScopedCFTypeRefTraits>(that) {}
55};
56
57}  // namespace base
58
59#endif  // BASE_MAC_SCOPED_CFTYPEREF_H_
60