base/prefs/pref_notifier_impl.cc

   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 #include "base/prefs/pref_notifier_impl.h"
   6
   7 #include "base/logging.h"
   8 #include "base/prefs/pref_service.h"
   9 #include "base/stl_util.h"
  10
  11 PrefNotifierImpl::PrefNotifierImpl()
  12     : pref_service_(NULL) {
  13 }
  14
  15 PrefNotifierImpl::PrefNotifierImpl(PrefService* service)
  16     : pref_service_(service) {
  17 }
  18
  19 PrefNotifierImpl::~PrefNotifierImpl() {
  20   DCHECK(thread_checker_.CalledOnValidThread());
  21
  22   // Verify that there are no pref observers when we shut down.
  23   for (PrefObserverMap::iterator it = pref_observers_.begin();
  24        it != pref_observers_.end(); ++it) {
  25     PrefObserverList::Iterator obs_iterator(it->second);
  26     if (obs_iterator.GetNext()) {
  27       LOG(WARNING) << "pref observer found at shutdown " << it->first;
  28     }
  29   }
  30
  31   // Same for initialization observers.
  32   if (!init_observers_.empty())
  33     LOG(WARNING) << "Init observer found at shutdown.";
  34
  35   STLDeleteContainerPairSecondPointers(pref_observers_.begin(),
  36                                        pref_observers_.end());
  37   pref_observers_.clear();
  38   init_observers_.clear();
  39 }
  40
  41 void PrefNotifierImpl::AddPrefObserver(const std::string& path,
  42                                        PrefObserver* obs) {
  43   // Get the pref observer list associated with the path.
  44   PrefObserverList* observer_list = NULL;
  45   const PrefObserverMap::iterator observer_iterator =
  46       pref_observers_.find(path);
  47   if (observer_iterator == pref_observers_.end()) {
  48     observer_list = new PrefObserverList;
  49     pref_observers_[path] = observer_list;
  50   } else {
  51     observer_list = observer_iterator->second;
  52   }
  53
  54   // Add the pref observer. ObserverList will DCHECK if it already is
  55   // in the list.
  56   observer_list->AddObserver(obs);
  57 }
  58
  59 void PrefNotifierImpl::RemovePrefObserver(const std::string& path,
  60                                           PrefObserver* obs) {
  61   DCHECK(thread_checker_.CalledOnValidThread());
  62
  63   const PrefObserverMap::iterator observer_iterator =
  64       pref_observers_.find(path);
  65   if (observer_iterator == pref_observers_.end()) {
  66     return;
  67   }
  68
  69   PrefObserverList* observer_list = observer_iterator->second;
  70   observer_list->RemoveObserver(obs);
  71 }
  72
  73 void PrefNotifierImpl::AddInitObserver(base::Callback<void(bool)> obs) {
  74   init_observers_.push_back(obs);
  75 }
  76
  77 void PrefNotifierImpl::OnPreferenceChanged(const std::string& path) {
  78   FireObservers(path);
  79 }
  80
  81 void PrefNotifierImpl::OnInitializationCompleted(bool succeeded) {
  82   DCHECK(thread_checker_.CalledOnValidThread());
  83
  84   // We must make a copy of init_observers_ and clear it before we run
  85   // observers, or we can end up in this method re-entrantly before
  86   // clearing the observers list.
  87   PrefInitObserverList observers(init_observers_);
  88   init_observers_.clear();
  89
  90   for (PrefInitObserverList::iterator it = observers.begin();
  91        it != observers.end();
  92        ++it) {
  93     it->Run(succeeded);
  94   }
  95 }
  96
  97 void PrefNotifierImpl::FireObservers(const std::string& path) {
  98   DCHECK(thread_checker_.CalledOnValidThread());
  99
 100   // Only send notifications for registered preferences.
 101   if (!pref_service_->FindPreference(path))
 102     return;
 103
 104   const PrefObserverMap::iterator observer_iterator =
 105       pref_observers_.find(path);
 106   if (observer_iterator == pref_observers_.end())
 107     return;
 108
 109   FOR_EACH_OBSERVER(PrefObserver,
 110                     *(observer_iterator->second),
 111                     OnPreferenceChanged(pref_service_, path));
 112 }
 113
 114 void PrefNotifierImpl::SetPrefService(PrefService* pref_service) {
 115   DCHECK(pref_service_ == NULL);
 116   pref_service_ = pref_service;
 117 }