content/browser/geolocation/geolocation_provider_impl.cc

   1 // Copyright (c) 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 "content/browser/geolocation/geolocation_provider_impl.h"
   6
   7 #include "base/bind.h"
   8 #include "base/bind_helpers.h"
   9 #include "base/callback.h"
  10 #include "base/location.h"
  11 #include "base/logging.h"
  12 #include "base/memory/singleton.h"
  13 #include "base/single_thread_task_runner.h"
  14 #include "content/browser/geolocation/location_arbitrator_impl.h"
  15 #include "content/public/browser/browser_thread.h"
  16
  17 namespace content {
  18
  19 GeolocationProvider* GeolocationProvider::GetInstance() {
  20   return GeolocationProviderImpl::GetInstance();
  21 }
  22
  23 scoped_ptr<GeolocationProvider::Subscription>
  24 GeolocationProviderImpl::AddLocationUpdateCallback(
  25     const LocationUpdateCallback& callback, bool use_high_accuracy) {
  26   DCHECK_CURRENTLY_ON(BrowserThread::UI);
  27   scoped_ptr<GeolocationProvider::Subscription> subscription;
  28   if (use_high_accuracy) {
  29     subscription = high_accuracy_callbacks_.Add(callback);
  30   } else {
  31     subscription = low_accuracy_callbacks_.Add(callback);
  32   }
  33
  34   OnClientsChanged();
  35   if (position_.Validate() ||
  36       position_.error_code != Geoposition::ERROR_CODE_NONE) {
  37     callback.Run(position_);
  38   }
  39
  40   return subscription.Pass();
  41 }
  42
  43 void GeolocationProviderImpl::UserDidOptIntoLocationServices() {
  44   DCHECK_CURRENTLY_ON(BrowserThread::UI);
  45   bool was_permission_granted = user_did_opt_into_location_services_;
  46   user_did_opt_into_location_services_ = true;
  47   if (IsRunning() && !was_permission_granted)
  48     InformProvidersPermissionGranted();
  49 }
  50
  51 void GeolocationProviderImpl::OverrideLocationForTesting(
  52     const Geoposition& position) {
  53   DCHECK_CURRENTLY_ON(BrowserThread::UI);
  54   ignore_location_updates_ = true;
  55   NotifyClients(position);
  56 }
  57
  58 void GeolocationProviderImpl::OnLocationUpdate(const Geoposition& position) {
  59   DCHECK(OnGeolocationThread());
  60   // Will be true only in testing.
  61   if (ignore_location_updates_)
  62     return;
  63   BrowserThread::PostTask(BrowserThread::UI,
  64                           FROM_HERE,
  65                           base::Bind(&GeolocationProviderImpl::NotifyClients,
  66                                      base::Unretained(this), position));
  67 }
  68
  69 GeolocationProviderImpl* GeolocationProviderImpl::GetInstance() {
  70   DCHECK_CURRENTLY_ON(BrowserThread::UI);
  71   return base::Singleton<GeolocationProviderImpl>::get();
  72 }
  73
  74 GeolocationProviderImpl::GeolocationProviderImpl()
  75     : base::Thread("Geolocation"),
  76       user_did_opt_into_location_services_(false),
  77       ignore_location_updates_(false),
  78       arbitrator_(NULL) {
  79   DCHECK_CURRENTLY_ON(BrowserThread::UI);
  80   high_accuracy_callbacks_.set_removal_callback(
  81       base::Bind(&GeolocationProviderImpl::OnClientsChanged,
  82                  base::Unretained(this)));
  83   low_accuracy_callbacks_.set_removal_callback(
  84       base::Bind(&GeolocationProviderImpl::OnClientsChanged,
  85                  base::Unretained(this)));
  86 }
  87
  88 GeolocationProviderImpl::~GeolocationProviderImpl() {
  89   Stop();
  90   DCHECK(!arbitrator_);
  91 }
  92
  93 bool GeolocationProviderImpl::OnGeolocationThread() const {
  94   return base::MessageLoop::current() == message_loop();
  95 }
  96
  97 void GeolocationProviderImpl::OnClientsChanged() {
  98   DCHECK_CURRENTLY_ON(BrowserThread::UI);
  99   base::Closure task;
 100   if (high_accuracy_callbacks_.empty() && low_accuracy_callbacks_.empty()) {
 101     DCHECK(IsRunning());
 102     if (!ignore_location_updates_) {
 103       // We have no more observers, so we clear the cached geoposition so that
 104       // when the next observer is added we will not provide a stale position.
 105       position_ = Geoposition();
 106     }
 107     task = base::Bind(&GeolocationProviderImpl::StopProviders,
 108                       base::Unretained(this));
 109   } else {
 110     if (!IsRunning()) {
 111       Start();
 112       if (user_did_opt_into_location_services_)
 113         InformProvidersPermissionGranted();
 114     }
 115     // Determine a set of options that satisfies all clients.
 116     bool use_high_accuracy = !high_accuracy_callbacks_.empty();
 117
 118     // Send the current options to the providers as they may have changed.
 119     task = base::Bind(&GeolocationProviderImpl::StartProviders,
 120                       base::Unretained(this),
 121                       use_high_accuracy);
 122   }
 123
 124   task_runner()->PostTask(FROM_HERE, task);
 125 }
 126
 127 void GeolocationProviderImpl::StopProviders() {
 128   DCHECK(OnGeolocationThread());
 129   DCHECK(arbitrator_);
 130   arbitrator_->StopProviders();
 131 }
 132
 133 void GeolocationProviderImpl::StartProviders(bool use_high_accuracy) {
 134   DCHECK(OnGeolocationThread());
 135   DCHECK(arbitrator_);
 136   arbitrator_->StartProviders(use_high_accuracy);
 137 }
 138
 139 void GeolocationProviderImpl::InformProvidersPermissionGranted() {
 140   DCHECK(IsRunning());
 141   if (!OnGeolocationThread()) {
 142     task_runner()->PostTask(
 143         FROM_HERE,
 144         base::Bind(&GeolocationProviderImpl::InformProvidersPermissionGranted,
 145                    base::Unretained(this)));
 146     return;
 147   }
 148   DCHECK(OnGeolocationThread());
 149   DCHECK(arbitrator_);
 150   arbitrator_->OnPermissionGranted();
 151 }
 152
 153 void GeolocationProviderImpl::NotifyClients(const Geoposition& position) {
 154   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 155   DCHECK(position.Validate() ||
 156          position.error_code != Geoposition::ERROR_CODE_NONE);
 157   position_ = position;
 158   high_accuracy_callbacks_.Notify(position_);
 159   low_accuracy_callbacks_.Notify(position_);
 160 }
 161
 162 void GeolocationProviderImpl::Init() {
 163   DCHECK(OnGeolocationThread());
 164   DCHECK(!arbitrator_);
 165   arbitrator_ = CreateArbitrator();
 166 }
 167
 168 void GeolocationProviderImpl::CleanUp() {
 169   DCHECK(OnGeolocationThread());
 170   delete arbitrator_;
 171   arbitrator_ = NULL;
 172 }
 173
 174 LocationArbitrator* GeolocationProviderImpl::CreateArbitrator() {
 175   LocationArbitratorImpl::LocationUpdateCallback callback = base::Bind(
 176       &GeolocationProviderImpl::OnLocationUpdate, base::Unretained(this));
 177   return new LocationArbitratorImpl(callback);
 178 }
 179
 180 }  // namespace content