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1 // Copyright 2014 The Chromium Authors. All rights reserved. | 1 // Copyright 2014 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #import "base/ios/crb_protocol_observers.h" | 5 #import "base/ios/crb_protocol_observers.h" |
6 | 6 |
7 #include <objc/runtime.h> | 7 #include <objc/runtime.h> |
8 #include <vector> | |
8 | 9 |
9 #include "base/logging.h" | 10 #include "base/logging.h" |
10 #include "base/mac/scoped_nsobject.h" | 11 #include "base/mac/scoped_nsobject.h" |
11 | 12 |
13 @interface CRBProtocolObservers () { | |
14 base::scoped_nsobject<Protocol> _protocol; | |
15 // ivar declared here are private to the implementation but must be | |
16 // public for allowing the C++ |Iterator| class access to those ivars. | |
17 @public | |
18 // vector of weak pointers to observers. | |
19 std::vector<__unsafe_unretained id> _observers; | |
20 // Indicate the nested level of observer iteration. | |
21 // A depth of 0 means nobody is currently iterating on the list of observers. | |
22 int _invocation_depth; | |
droger
2015/06/04 12:29:53
_invocationDepth
jbbegue
2015/06/04 12:41:45
Done.
| |
23 } | |
24 | |
25 // The methods will remove nil observers from the list and will be called when | |
droger
2015/06/04 12:29:53
s/will remove/removes/
s/will be/is/
jbbegue
2015/06/04 12:41:46
Done.
| |
26 // the |_invocation_depth| reaches 0. | |
27 - (void)compact; | |
28 | |
29 @end | |
30 | |
31 namespace { | |
32 | |
33 class Iterator { | |
34 public: | |
35 explicit Iterator(CRBProtocolObservers* protocol_observers); | |
36 ~Iterator(); | |
37 id GetNext(); | |
38 | |
39 private: | |
40 CRBProtocolObservers* protocol_observers_; | |
41 size_t index_; | |
42 size_t max_index_; | |
43 }; | |
44 | |
45 Iterator::Iterator(CRBProtocolObservers* protocol_observers) | |
46 : protocol_observers_(protocol_observers), | |
47 index_(0), | |
48 max_index_(protocol_observers->_observers.size()) { | |
49 DCHECK(protocol_observers_); | |
50 ++protocol_observers->_invocation_depth; | |
51 } | |
52 | |
53 Iterator::~Iterator() { | |
54 if (protocol_observers_ && --protocol_observers_->_invocation_depth == 0) | |
55 [protocol_observers_ compact]; | |
56 } | |
57 | |
58 id Iterator::GetNext() { | |
59 if (!protocol_observers_) | |
60 return nil; | |
61 auto& observers = protocol_observers_->_observers; | |
62 // Skip null elements. | |
63 size_t max_index = std::min(max_index_, observers.size()); | |
64 while (index_ < max_index && !observers[index_]) | |
65 ++index_; | |
66 return index_ < max_index ? observers[index_++] : nil; | |
67 } | |
68 } | |
69 | |
12 @interface CRBProtocolObservers () | 70 @interface CRBProtocolObservers () |
13 | 71 |
14 // Designated initializer. | 72 // Designated initializer. |
15 - (id)initWithProtocol:(Protocol*)protocol; | 73 - (id)initWithProtocol:(Protocol*)protocol; |
16 | 74 |
17 @end | 75 @end |
18 | 76 |
19 @implementation CRBProtocolObservers { | 77 @implementation CRBProtocolObservers |
20 base::scoped_nsobject<Protocol> _protocol; | |
21 base::scoped_nsobject<NSHashTable> _observers; | |
22 } | |
23 | 78 |
24 + (CRBProtocolObservers*)observersWithProtocol:(Protocol*)protocol { | 79 + (instancetype)observersWithProtocol:(Protocol*)protocol { |
25 return [[[self alloc] initWithProtocol:protocol] autorelease]; | 80 return [[[self alloc] initWithProtocol:protocol] autorelease]; |
26 } | 81 } |
27 | 82 |
28 - (id)init { | 83 - (id)init { |
29 NOTREACHED(); | 84 NOTREACHED(); |
30 return nil; | 85 return nil; |
31 } | 86 } |
32 | 87 |
33 - (id)initWithProtocol:(Protocol*)protocol { | 88 - (id)initWithProtocol:(Protocol*)protocol { |
34 self = [super init]; | 89 self = [super init]; |
35 if (self) { | 90 if (self) { |
36 _protocol.reset([protocol retain]); | 91 _protocol.reset([protocol retain]); |
37 _observers.reset([[NSHashTable weakObjectsHashTable] retain]); | |
38 } | 92 } |
39 return self; | 93 return self; |
40 } | 94 } |
41 | 95 |
42 - (Protocol*)protocol { | 96 - (Protocol*)protocol { |
43 return _protocol.get(); | 97 return _protocol.get(); |
44 } | 98 } |
45 | 99 |
46 - (void)addObserver:(id)observer { | 100 - (void)addObserver:(id)observer { |
101 DCHECK(observer); | |
47 DCHECK([observer conformsToProtocol:self.protocol]); | 102 DCHECK([observer conformsToProtocol:self.protocol]); |
48 [_observers addObject:observer]; | 103 |
104 if (std::find(_observers.begin(), _observers.end(), observer) != | |
105 _observers.end()) | |
106 return; | |
107 | |
108 _observers.push_back(observer); | |
49 } | 109 } |
50 | 110 |
51 - (void)removeObserver:(id)observer { | 111 - (void)removeObserver:(id)observer { |
52 [_observers removeObject:observer]; | 112 DCHECK(observer); |
113 auto it = std::find(_observers.begin(), _observers.end(), observer); | |
114 if (it != _observers.end()) { | |
115 if (_invocation_depth) | |
116 *it = nil; | |
117 else | |
118 _observers.erase(it); | |
119 } | |
120 } | |
121 | |
122 - (BOOL)empty { | |
123 return _observers.empty(); | |
53 } | 124 } |
54 | 125 |
55 #pragma mark - NSObject | 126 #pragma mark - NSObject |
56 | 127 |
57 - (NSMethodSignature*)methodSignatureForSelector:(SEL)selector { | 128 - (NSMethodSignature*)methodSignatureForSelector:(SEL)selector { |
58 NSMethodSignature* signature = [super methodSignatureForSelector:selector]; | 129 NSMethodSignature* signature = [super methodSignatureForSelector:selector]; |
59 if (signature) | 130 if (signature) |
60 return signature; | 131 return signature; |
61 | 132 |
62 // Look for a required method in the protocol. protocol_getMethodDescription | 133 // Look for a required method in the protocol. protocol_getMethodDescription |
(...skipping 10 matching lines...) Expand all Loading... | |
73 return [NSMethodSignature signatureWithObjCTypes:description.types]; | 144 return [NSMethodSignature signatureWithObjCTypes:description.types]; |
74 | 145 |
75 // There is neither a required nor optional method with this selector in the | 146 // There is neither a required nor optional method with this selector in the |
76 // protocol, so invoke -[NSObject doesNotRecognizeSelector:] to raise | 147 // protocol, so invoke -[NSObject doesNotRecognizeSelector:] to raise |
77 // NSInvalidArgumentException. | 148 // NSInvalidArgumentException. |
78 [self doesNotRecognizeSelector:selector]; | 149 [self doesNotRecognizeSelector:selector]; |
79 return nil; | 150 return nil; |
80 } | 151 } |
81 | 152 |
82 - (void)forwardInvocation:(NSInvocation*)invocation { | 153 - (void)forwardInvocation:(NSInvocation*)invocation { |
154 DCHECK(invocation); | |
155 if (_observers.empty()) | |
156 return; | |
83 SEL selector = [invocation selector]; | 157 SEL selector = [invocation selector]; |
84 base::scoped_nsobject<NSArray> observers([[_observers allObjects] retain]); | 158 Iterator it(self); |
85 for (id observer in observers.get()) { | 159 id observer; |
160 while ((observer = it.GetNext()) != nil) { | |
86 if ([observer respondsToSelector:selector]) | 161 if ([observer respondsToSelector:selector]) |
87 [invocation invokeWithTarget:observer]; | 162 [invocation invokeWithTarget:observer]; |
88 } | 163 } |
89 } | 164 } |
90 | 165 |
91 - (void)executeOnObservers:(ExecutionWithObserverBlock)callback { | 166 - (void)executeOnObservers:(ExecutionWithObserverBlock)callback { |
92 DCHECK(callback); | 167 DCHECK(callback); |
93 base::scoped_nsobject<NSArray> observers([[_observers allObjects] retain]); | 168 if (_observers.empty()) |
94 for (id observer in observers.get()) { | 169 return; |
170 Iterator it(self); | |
171 id observer; | |
172 while ((observer = it.GetNext()) != nil) | |
95 callback(observer); | 173 callback(observer); |
96 } | 174 } |
175 | |
176 #pragma mark - Private | |
177 | |
178 - (void)compact { | |
179 _observers.erase(std::remove(_observers.begin(), _observers.end(), nil), | |
sdefresne
2015/06/04 12:32:48
nit: DCHECK(!_invocation_depth);
jbbegue
2015/06/04 12:41:46
Done.
| |
180 _observers.end()); | |
97 } | 181 } |
98 | 182 |
99 @end | 183 @end |
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