base/prefs/scoped_user_pref_update.cc

   1 // Copyright 2013 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/scoped_user_pref_update.h"
   6
   7 #include "base/logging.h"
   8 #include "base/prefs/pref_notifier.h"
   9 #include "base/prefs/pref_service.h"
  10
  11 namespace subtle {
  12
  13 ScopedUserPrefUpdateBase::ScopedUserPrefUpdateBase(PrefService* service,
  14                                                    const std::string& path)
  15     : service_(service), path_(path), value_(NULL) {
  16   DCHECK(service_->CalledOnValidThread());
  17 }
  18
  19 ScopedUserPrefUpdateBase::~ScopedUserPrefUpdateBase() {
  20   Notify();
  21 }
  22
  23 base::Value* ScopedUserPrefUpdateBase::GetValueOfType(base::Value::Type type) {
  24   DCHECK(CalledOnValidThread());
  25   if (!value_)
  26     value_ = service_->GetMutableUserPref(path_, type);
  27   return value_;
  28 }
  29
  30 void ScopedUserPrefUpdateBase::Notify() {
  31   if (value_) {
  32     service_->ReportUserPrefChanged(path_);
  33     value_ = NULL;
  34   }
  35 }
  36
  37 }  // namespace subtle