Fix for Bug 50726 "Save extension list and "winning" prefs from extensions"

chrome/browser/extensions/extension_pref_store.cc

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "chrome/browser/extensions/extension_pref_store.h"
-
-#include "base/logging.h"
-#include "base/values.h"
-#include "chrome/browser/browser_process.h"
-#include "chrome/browser/prefs/pref_service.h"
-#include "chrome/browser/profiles/profile.h"
-#include "chrome/common/extensions/extension.h"
-#include "chrome/common/notification_service.h"
-
-ExtensionPrefStore::ExtensionPrefStore(Profile* profile,
-                                       PrefNotifier::PrefStoreType type)
-    : prefs_(new DictionaryValue()),
-      profile_(profile),
-      type_(type) {
-  RegisterObservers();
-}
-
-ExtensionPrefStore::~ExtensionPrefStore() {
-  STLDeleteElements(&extension_stack_);
-  notification_registrar_.RemoveAll();
-}
-
-void ExtensionPrefStore::InstallExtensionPref(const Extension* extension,
-                                              const char* new_pref_path,
-                                              Value* new_pref_value) {
-  ExtensionStack::iterator i;
-  for (i = extension_stack_.begin(); i != extension_stack_.end(); ++i) {
-    if ((*i)->extension == extension)
-      break;
-  }
-
-  // If this extension is not already in the stack, add it. Otherwise, update
-  // or add the value of this preference, but don't change the extension's
-  // position in the stack. We store the extension even if this preference
-  // isn't registered with our PrefService, so that the ordering of extensions
-  // is consistent among all local-state and user ExtensionPrefStores.
-  PrefService* pref_service = GetPrefService();
-  // The pref_service may be NULL in unit testing.
-  bool is_registered_pref = (pref_service == NULL ||
-      pref_service->FindPreference(new_pref_path) != NULL);
-  PrefValueMap* pref_values;
-  if (i == extension_stack_.end()) {
-    pref_values = new PrefValueMap();
-    if (is_registered_pref)
-      (*pref_values)[new_pref_path] = new_pref_value;
-
-    ExtensionPrefs* extension_prefs = new ExtensionPrefs(extension,
-                                                         pref_values);
-    extension_stack_.push_front(extension_prefs);
-  } else if (is_registered_pref) {
-    pref_values = (*i)->pref_values;
-    delete (*pref_values)[new_pref_path];
-    (*pref_values)[new_pref_path] = new_pref_value;
-  }
-
-  // Apply the preference to our local |prefs_| store.
-  UpdateOnePref(new_pref_path);
-}
-
-void ExtensionPrefStore::UninstallExtension(const Extension* extension) {
-  // Remove this extension from the stack.
-  for (ExtensionStack::iterator i = extension_stack_.begin();
-      i != extension_stack_.end(); ++i) {
-    if ((*i)->extension == extension) {
-      scoped_ptr<ExtensionPrefs> to_be_deleted(*i);
-      extension_stack_.erase(i);
-      UpdatePrefs(to_be_deleted->pref_values);
-      return;
-    }
-  }
-}
-
-void ExtensionPrefStore::GetExtensionIDs(std::vector<std::string>* result) {
-  for (ExtensionStack::iterator i = extension_stack_.begin();
-      i != extension_stack_.end(); ++i) {
-    (*result).push_back((*i)->extension->id());
-  }
-}
-
-// This could be sped up by keeping track of which extension currently controls
-// a given preference, among other optimizations. But probably fewer than 10
-// installed extensions will be trying to control any preferences, so stick
-// with this simpler algorithm until it causes a problem.
-void ExtensionPrefStore::UpdateOnePref(const char* path) {
-  PrefService* pref_service = GetPrefService();
-
-  // There are at least two PrefServices, one for local state and one for
-  // user prefs. (See browser_main.cc.) Different preferences are registered
-  // in each; if this one doesn't have the desired pref registered, we ignore
-  // it and let the other one handle it.
-  // The pref_service may be NULL in unit testing.
-  if (pref_service && !pref_service->FindPreference(path))
-      return;
-
-  // Save the old value before removing it from the local cache.
-  Value* my_old_value_ptr = NULL;
-  prefs_->Get(path, &my_old_value_ptr);
-  scoped_ptr<Value> my_old_value;
-  if (my_old_value_ptr)
-    my_old_value.reset(my_old_value_ptr->DeepCopy());
-
-  // DictionaryValue::Set complains if a key is overwritten with the same
-  // value, so remove it first.
-  prefs_->Remove(path, NULL);
-
-  // Find the first extension that wants to set this pref and use its value.
-  Value* my_new_value = NULL;
-  for (ExtensionStack::iterator ext_iter = extension_stack_.begin();
-        ext_iter != extension_stack_.end(); ++ext_iter) {
-    PrefValueMap::iterator value_iter = (*ext_iter)->pref_values->find(path);
-    if (value_iter != (*ext_iter)->pref_values->end()) {
-      prefs_->Set(path, (*value_iter).second->DeepCopy());
-      my_new_value = (*value_iter).second;
-      break;
-    }
-  }
-
-  if (pref_service) {
-    bool value_changed = true;
-    if (!my_old_value.get() && !my_new_value) {
-      value_changed = false;
-    } else if (my_old_value.get() &&
-               my_new_value &&
-               my_old_value->Equals(my_new_value)) {
-      value_changed = false;
-    }
-
-    if (value_changed)
-      pref_service->pref_notifier()->OnPreferenceSet(path, type_);
-  }
-}
-
-void ExtensionPrefStore::UpdatePrefs(const PrefValueMap* pref_values) {
-  if (!pref_values)
-    return;
-
-  for (PrefValueMap::const_iterator i = pref_values->begin();
-        i != pref_values->end(); ++i) {
-    UpdateOnePref(i->first);
-  }
-}
-
-PrefService* ExtensionPrefStore::GetPrefService() {
-  if (profile_)
-    return profile_->GetPrefs();
-  return g_browser_process->local_state();
-}
-
-void ExtensionPrefStore::RegisterObservers() {
-  notification_registrar_.Add(this,
-                              NotificationType::EXTENSION_PREF_CHANGED,
-                              NotificationService::AllSources());
-
-  notification_registrar_.Add(this,
-                              NotificationType::EXTENSION_UNLOADED,
-                              NotificationService::AllSources());
-}
-
-void ExtensionPrefStore::Observe(NotificationType type,
-                                 const NotificationSource& source,
-                                 const NotificationDetails& details) {
-  switch (type.value) {
-    case NotificationType::EXTENSION_PREF_CHANGED: {
-      Profile* extension_profile = Source<Profile>(source).ptr();
-      // The ExtensionPrefStore for the local state watches all profiles.
-      if (!profile_ || profile_ == extension_profile) {
-        ExtensionPrefStore::ExtensionPrefDetails* data =
-            Details<ExtensionPrefStore::ExtensionPrefDetails>(details).ptr();
-        InstallExtensionPref(data->first, data->second.first,
-            data->second.second);
-      }
-      break;
-    }
-    case NotificationType::EXTENSION_UNLOADED: {
-      Profile* extension_profile = Source<Profile>(source).ptr();
-      const Extension* extension = Details<const Extension>(details).ptr();
-      // The ExtensionPrefStore for the local state watches all profiles.
-      if (profile_ == NULL || profile_ == extension_profile)
-        UninstallExtension(extension);
-      break;
-    }
-    default: {
-      NOTREACHED();
-    }
-  }
-}
-
-ExtensionPrefStore::ExtensionPrefs::ExtensionPrefs(const Extension* extension,
-    PrefValueMap* values) : extension(extension), pref_values(values) {}
-
-ExtensionPrefStore::ExtensionPrefs::~ExtensionPrefs() {
-  STLDeleteValues(pref_values);
-  delete pref_values;
-}