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.
5
#ifndef BASE_SCOPED_OBSERVER_H_
6
#define BASE_SCOPED_OBSERVER_H_
11
#include "base/basictypes.h"
13
// ScopedObserver is used to keep track of the set of sources an object has
14
// attached itself to as an observer. When ScopedObserver is destroyed it
15
// removes the object as an observer from all sources it has been added to.
16
template <class Source, class Observer>
17
class ScopedObserver {
19
explicit ScopedObserver(Observer* observer) : observer_(observer) {}
22
for (size_t i = 0; i < sources_.size(); ++i)
23
sources_[i]->RemoveObserver(observer_);
26
// Adds the object passed to the constructor as an observer on |source|.
27
void Add(Source* source) {
28
sources_.push_back(source);
29
source->AddObserver(observer_);
32
// Remove the object passed to the constructor as an observer from |source|.
33
void Remove(Source* source) {
34
sources_.erase(std::find(sources_.begin(), sources_.end(), source));
35
source->RemoveObserver(observer_);
38
bool IsObserving(Source* source) const {
39
for (size_t i = 0; i < sources_.size(); ++i) {
40
if (sources_[i] == source)
49
std::vector<Source*> sources_;
51
DISALLOW_COPY_AND_ASSIGN(ScopedObserver);
54
#endif // BASE_SCOPED_OBSERVER_H_