chrome/browser/extensions/api/preference/chrome_direct_setting_api.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 "chrome/browser/extensions/api/preference/chrome_direct_setting_api.h"
   6
   7 #include "base/bind.h"
   8 #include "base/containers/hash_tables.h"
   9 #include "base/lazy_instance.h"
  10 #include "base/prefs/pref_change_registrar.h"
  11 #include "base/prefs/pref_service.h"
  12 #include "base/strings/stringprintf.h"
  13 #include "chrome/browser/extensions/api/preference/preference_api_constants.h"
  14 #include "chrome/browser/profiles/profile.h"
  15 #include "extensions/browser/extension_registry.h"
  16
  17 namespace extensions {
  18 namespace chromedirectsetting {
  19
  20 const char kOnPrefChangeFormat[] =
  21     "types.private.ChromeDirectSetting.%s.onChange";
  22
  23 class PreferenceWhitelist {
  24  public:
  25   PreferenceWhitelist() {
  26     // Note: DO NOT add any setting here that does not have a UI element in
  27     // chrome://settings unless you write a component extension that is always
  28     // installed. Otherwise, users may install your extension, the extension may
  29     // toggle settings, and after the extension has been disabled/uninstalled
  30     // the toggled setting remains in place. See http://crbug.com/164227#c157 .
  31     whitelist_.insert("googlegeolocationaccess.enabled");
  32     // The following settings need to be checked and probably removed. See
  33     // http://crbug.com/164227#c157 .
  34     whitelist_.insert("spdy_proxy.enabled");
  35     whitelist_.insert("data_reduction.daily_original_length");
  36     whitelist_.insert("data_reduction.daily_received_length");
  37     whitelist_.insert("data_reduction.update_daily_lengths");
  38     whitelist_.insert("easy_unlock.proximity_required");
  39   }
  40
  41   ~PreferenceWhitelist() {}
  42
  43   bool IsPreferenceOnWhitelist(const std::string& pref_key){
  44     return whitelist_.find(pref_key) != whitelist_.end();
  45   }
  46
  47   void RegisterEventListeners(
  48       Profile* profile,
  49       EventRouter::Observer* observer) {
  50     for (base::hash_set<std::string>::iterator iter = whitelist_.begin();
  51          iter != whitelist_.end();
  52          iter++) {
  53       std::string event_name = base::StringPrintf(
  54           kOnPrefChangeFormat,
  55           (*iter).c_str());
  56       EventRouter::Get(profile)->RegisterObserver(observer, event_name);
  57     }
  58   }
  59
  60   void RegisterPropertyListeners(
  61       Profile* profile,
  62       PrefChangeRegistrar* registrar,
  63       const base::Callback<void(const std::string&)>& callback) {
  64     for (base::hash_set<std::string>::iterator iter = whitelist_.begin();
  65          iter != whitelist_.end();
  66          iter++) {
  67       const char* pref_key = (*iter).c_str();
  68       std::string event_name = base::StringPrintf(
  69           kOnPrefChangeFormat,
  70           pref_key);
  71       registrar->Add(pref_key, callback);
  72     }
  73   }
  74
  75  private:
  76   base::hash_set<std::string> whitelist_;
  77
  78   DISALLOW_COPY_AND_ASSIGN(PreferenceWhitelist);
  79 };
  80
  81 base::LazyInstance<PreferenceWhitelist> preference_whitelist =
  82     LAZY_INSTANCE_INITIALIZER;
  83
  84 static base::LazyInstance<
  85     BrowserContextKeyedAPIFactory<ChromeDirectSettingAPI> > g_factory =
  86     LAZY_INSTANCE_INITIALIZER;
  87
  88 ChromeDirectSettingAPI::ChromeDirectSettingAPI(content::BrowserContext* context)
  89     : profile_(Profile::FromBrowserContext(context)) {
  90   preference_whitelist.Get().RegisterEventListeners(profile_, this);
  91 }
  92
  93 ChromeDirectSettingAPI::~ChromeDirectSettingAPI() {}
  94
  95 // KeyedService implementation.
  96 void ChromeDirectSettingAPI::Shutdown() {}
  97
  98 // BrowserContextKeyedAPI implementation.
  99 BrowserContextKeyedAPIFactory<ChromeDirectSettingAPI>*
 100 ChromeDirectSettingAPI::GetFactoryInstance() {
 101   return g_factory.Pointer();
 102 }
 103
 104 // EventRouter::Observer implementation.
 105 void ChromeDirectSettingAPI::OnListenerAdded(const EventListenerInfo& details) {
 106   EventRouter::Get(profile_)->UnregisterObserver(this);
 107   registrar_.Init(profile_->GetPrefs());
 108   preference_whitelist.Get().RegisterPropertyListeners(
 109       profile_,
 110       &registrar_,
 111       base::Bind(&ChromeDirectSettingAPI::OnPrefChanged,
 112                  base::Unretained(this),
 113                  registrar_.prefs()));
 114 }
 115
 116 bool ChromeDirectSettingAPI::IsPreferenceOnWhitelist(
 117     const std::string& pref_key) {
 118   return preference_whitelist.Get().IsPreferenceOnWhitelist(pref_key);
 119 }
 120
 121 ChromeDirectSettingAPI* ChromeDirectSettingAPI::Get(
 122     content::BrowserContext* context) {
 123   return BrowserContextKeyedAPIFactory<ChromeDirectSettingAPI>::Get(context);
 124 }
 125
 126 // BrowserContextKeyedAPI implementation.
 127 const char* ChromeDirectSettingAPI::service_name() {
 128   return "ChromeDirectSettingAPI";
 129 }
 130
 131 void ChromeDirectSettingAPI::OnPrefChanged(
 132     PrefService* pref_service, const std::string& pref_key) {
 133   std::string event_name = base::StringPrintf(kOnPrefChangeFormat,
 134                                               pref_key.c_str());
 135   EventRouter* router = EventRouter::Get(profile_);
 136   if (router && router->HasEventListener(event_name)) {
 137     const PrefService::Preference* preference =
 138         profile_->GetPrefs()->FindPreference(pref_key.c_str());
 139     const base::Value* value = preference->GetValue();
 140
 141     scoped_ptr<base::DictionaryValue> result(new base::DictionaryValue);
 142     result->Set(preference_api_constants::kValue, value->DeepCopy());
 143     base::ListValue args;
 144     args.Append(result.release());
 145
 146     for (const scoped_refptr<const extensions::Extension>& extension :
 147          ExtensionRegistry::Get(profile_)->enabled_extensions()) {
 148       const std::string& extension_id = extension->id();
 149       if (router->ExtensionHasEventListener(extension_id, event_name)) {
 150         scoped_ptr<base::ListValue> args_copy(args.DeepCopy());
 151         scoped_ptr<Event> event(new Event(event_name, args_copy.Pass()));
 152         router->DispatchEventToExtension(extension_id, event.Pass());
 153       }
 154     }
 155   }
 156 }
 157
 158 }  // namespace chromedirectsetting
 159 }  // namespace extensions