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// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#import "base/ios/crb_protocol_observers.h"
#include <objc/runtime.h>
#include "base/logging.h"
#include "base/mac/scoped_nsobject.h"
@interface CRBProtocolObservers ()
// Designated initializer.
- (id)initWithProtocol:(Protocol*)protocol;
@end
@implementation CRBProtocolObservers {
base::scoped_nsobject<Protocol> _protocol;
base::scoped_nsobject<NSHashTable> _observers;
}
+ (CRBProtocolObservers*)observersWithProtocol:(Protocol*)protocol {
return [[[self alloc] initWithProtocol:protocol] autorelease];
}
- (id)init {
NOTREACHED();
return nil;
}
- (id)initWithProtocol:(Protocol*)protocol {
self = [super init];
if (self) {
_protocol.reset([protocol retain]);
_observers.reset([[NSHashTable weakObjectsHashTable] retain]);
}
return self;
}
- (Protocol*)protocol {
return _protocol.get();
}
- (void)addObserver:(id)observer {
DCHECK([observer conformsToProtocol:self.protocol]);
[_observers addObject:observer];
}
- (void)removeObserver:(id)observer {
[_observers removeObject:observer];
}
#pragma mark - NSObject
- (NSMethodSignature*)methodSignatureForSelector:(SEL)selector {
NSMethodSignature* signature = [super methodSignatureForSelector:selector];
if (signature)
return signature;
// Look for a required method in the protocol. protocol_getMethodDescription
// returns a struct whose fields are null if a method for the selector was
// not found.
struct objc_method_description description =
protocol_getMethodDescription(self.protocol, selector, YES, YES);
if (description.types)
return [NSMethodSignature signatureWithObjCTypes:description.types];
// Look for an optional method in the protocol.
description = protocol_getMethodDescription(self.protocol, selector, NO, YES);
if (description.types)
return [NSMethodSignature signatureWithObjCTypes:description.types];
// There is neither a required nor optional method with this selector in the
// protocol, so invoke -[NSObject doesNotRecognizeSelector:] to raise
// NSInvalidArgumentException.
[self doesNotRecognizeSelector:selector];
return nil;
}
- (void)forwardInvocation:(NSInvocation*)invocation {
SEL selector = [invocation selector];
base::scoped_nsobject<NSArray> observers([[_observers allObjects] retain]);
for (id observer in observers.get()) {
if ([observer respondsToSelector:selector])
[invocation invokeWithTarget:observer];
}
}
- (void)executeOnObservers:(ExecutionWithObserverBlock)callback {
DCHECK(callback);
base::scoped_nsobject<NSArray> observers([[_observers allObjects] retain]);
for (id observer in observers.get()) {
callback(observer);
}
}
@end
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