base/prefs/pref_change_registrar.cc

   1 // Copyright (c) 2010 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_change_registrar.h"
   6
   7 #include "base/bind.h"
   8 #include "base/logging.h"
   9 #include "base/prefs/pref_service.h"
  10
  11 PrefChangeRegistrar::PrefChangeRegistrar() : service_(NULL) {}
  12
  13 PrefChangeRegistrar::~PrefChangeRegistrar() {
  14   // If you see an invalid memory access in this destructor, this
  15   // PrefChangeRegistrar might be subscribed to an OffTheRecordProfileImpl that
  16   // has been destroyed. This should not happen any more but be warned.
  17   // Feel free to contact battre@chromium.org in case this happens.
  18   RemoveAll();
  19 }
  20
  21 void PrefChangeRegistrar::Init(PrefService* service) {
  22   DCHECK(IsEmpty() || service_ == service);
  23   service_ = service;
  24 }
  25
  26 void PrefChangeRegistrar::Add(const std::string& path,
  27                               const base::Closure& obs) {
  28   Add(path, base::Bind(&PrefChangeRegistrar::InvokeUnnamedCallback, obs));
  29 }
  30
  31 void PrefChangeRegistrar::Add(const std::string& path,
  32                               const NamedChangeCallback& obs) {
  33   if (!service_) {
  34     NOTREACHED();
  35     return;
  36   }
  37   DCHECK(!IsObserved(path)) << "Already had this pref registered.";
  38
  39   service_->AddPrefObserver(path, this);
  40   observers_[path] = obs;
  41 }
  42
  43 void PrefChangeRegistrar::Remove(const std::string& path) {
  44   DCHECK(IsObserved(path));
  45
  46   observers_.erase(path);
  47   service_->RemovePrefObserver(path, this);
  48 }
  49
  50 void PrefChangeRegistrar::RemoveAll() {
  51   for (ObserverMap::const_iterator it = observers_.begin();
  52        it != observers_.end(); ++it) {
  53     service_->RemovePrefObserver(it->first, this);
  54   }
  55
  56   observers_.clear();
  57 }
  58
  59 bool PrefChangeRegistrar::IsEmpty() const {
  60   return observers_.empty();
  61 }
  62
  63 bool PrefChangeRegistrar::IsObserved(const std::string& pref) {
  64   return observers_.find(pref) != observers_.end();
  65 }
  66
  67 bool PrefChangeRegistrar::IsManaged() {
  68   for (ObserverMap::const_iterator it = observers_.begin();
  69        it != observers_.end(); ++it) {
  70     const PrefService::Preference* pref = service_->FindPreference(it->first);
  71     if (pref && pref->IsManaged())
  72       return true;
  73   }
  74   return false;
  75 }
  76
  77 void PrefChangeRegistrar::OnPreferenceChanged(PrefService* service,
  78                                               const std::string& pref) {
  79   if (IsObserved(pref))
  80     observers_[pref].Run(pref);
  81 }
  82
  83 void PrefChangeRegistrar::InvokeUnnamedCallback(const base::Closure& callback,
  84                                                 const std::string& pref_name) {
  85   callback.Run();
  86 }
  87
  88 PrefService* PrefChangeRegistrar::prefs() {
  89   return service_;
  90 }
  91
  92 const PrefService* PrefChangeRegistrar::prefs() const {
  93   return service_;
  94 }