ios/chrome/browser/search_engines/search_engines_util.cc

   1 // Copyright 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 "ios/chrome/browser/search_engines/search_engines_util.h"
   6
   7 #include "base/message_loop/message_loop.h"
   8 #include "base/prefs/pref_service.h"
   9 #include "components/search_engines/search_engines_pref_names.h"
  10 #include "components/search_engines/template_url_prepopulate_data.h"
  11 #include "components/search_engines/template_url_service.h"
  12 #include "components/search_engines/template_url_service_observer.h"
  13
  14 namespace {
  15
  16 // Id of the google id in template_url_prepopulate_data.cc.
  17 static const int kGoogleEnginePrepopulatedId = 1;
  18
  19 // Update the search engine of the given service to the default ones for the
  20 // current locale.
  21 void UpdateSearchEngine(TemplateURLService* service) {
  22   DCHECK(service);
  23   DCHECK(service->loaded());
  24   std::vector<TemplateURL*> old_engines = service->GetTemplateURLs();
  25   size_t default_engine;
  26   ScopedVector<TemplateURLData> new_engines =
  27       TemplateURLPrepopulateData::GetPrepopulatedEngines(nullptr,
  28                                                          &default_engine);
  29   DCHECK(default_engine == 0);
  30   DCHECK(new_engines[0]->prepopulate_id == kGoogleEnginePrepopulatedId);
  31   // The aim is to replace the old search engines with the new ones.
  32   // It is not possible to remove all of them, because removing the current
  33   // selected engine is not allowed.
  34   // It is not possible to add all the new ones first, because the service gets
  35   // confused when a prepopulated engine is there more than once.
  36   // Instead, this will in a first pass makes google as the default engine. In
  37   // a second pass, it will remove all other search engine. At last, in a third
  38   // pass, it will add all new engine but google.
  39   for (const auto& engine : old_engines) {
  40     if (engine->prepopulate_id() == kGoogleEnginePrepopulatedId)
  41       service->SetUserSelectedDefaultSearchProvider(engine);
  42   }
  43   for (const auto& engine : old_engines) {
  44     if (engine->prepopulate_id() != kGoogleEnginePrepopulatedId)
  45       service->Remove(engine);
  46   }
  47   ScopedVector<TemplateURLData>::iterator it = new_engines.begin();
  48   while (it != new_engines.end()) {
  49     if ((*it)->prepopulate_id != kGoogleEnginePrepopulatedId) {
  50       // service->Add takes ownership on Added TemplateURL.
  51       service->Add(new TemplateURL(**it));
  52       it = new_engines.weak_erase(it);
  53     } else {
  54       ++it;
  55     }
  56   }
  57 }
  58
  59 // Observer class that allows to wait for the TemplateURLService to be loaded.
  60 // This class will delete itself as soon as the TemplateURLService is loaded.
  61 class LoadedObserver : public TemplateURLServiceObserver {
  62  public:
  63   explicit LoadedObserver(TemplateURLService* service) : service_(service) {
  64     DCHECK(service_);
  65     DCHECK(!service_->loaded());
  66     service_->AddObserver(this);
  67     service_->Load();
  68   }
  69
  70   ~LoadedObserver() override { service_->RemoveObserver(this); }
  71
  72   void OnTemplateURLServiceChanged() override {
  73     service_->RemoveObserver(this);
  74     UpdateSearchEngine(service_);
  75     // Only delete this class when this callback is finished.
  76     base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);
  77   }
  78
  79  private:
  80   TemplateURLService* service_;
  81 };
  82
  83 }  // namespace
  84
  85 namespace search_engines {
  86
  87 void UpdateSearchEnginesIfNeeded(PrefService* preferences,
  88                                  TemplateURLService* service) {
  89   if (!preferences->HasPrefPath(prefs::kCountryIDAtInstall)) {
  90     // No search engines were ever installed, just return.
  91     return;
  92   }
  93   int old_country_id = preferences->GetInteger(prefs::kCountryIDAtInstall);
  94   int country_id = TemplateURLPrepopulateData::GetCurrentCountryID();
  95   if (country_id == old_country_id) {
  96     // User's locale did not change, just return.
  97     return;
  98   }
  99   preferences->SetInteger(prefs::kCountryIDAtInstall, country_id);
 100   // If the current search engine is managed by policy then we can't set the
 101   // default search engine, which is required by UpdateSearchEngine(). This
 102   // isn't a problem as long as the default search engine is enforced via
 103   // policy, because it can't be changed by the user anyway; if the policy is
 104   // removed then the engines can be updated again.
 105   if (!service || service->is_default_search_managed())
 106     return;
 107   if (service->loaded())
 108     UpdateSearchEngine(service);
 109   else
 110     new LoadedObserver(service);  // The observer manages its own lifetime.
 111 }
 112
 113 }  // namespace search_engines