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/location_arbitrator_impl.h"
6
7 #include <map>
8
9 #include "base/bind.h"
10 #include "base/bind_helpers.h"
11 #include "content/browser/geolocation/network_location_provider.h"
12 #include "content/public/browser/access_token_store.h"
13 #include "content/public/browser/content_browser_client.h"
14 #include "content/public/common/content_client.h"
15 #include "url/gurl.h"
16
17 namespace content {
18 namespace {
19
20 const char* kDefaultNetworkProviderUrl =
21 "https://www.googleapis.com/geolocation/v1/geolocate";
22 } // namespace
23
24 // To avoid oscillations, set this to twice the expected update interval of a
25 // a GPS-type location provider (in case it misses a beat) plus a little.
26 const int64 LocationArbitratorImpl::kFixStaleTimeoutMilliseconds =
27 11 * base::Time::kMillisecondsPerSecond;
28
LocationArbitratorImpl(const LocationUpdateCallback & callback)29 LocationArbitratorImpl::LocationArbitratorImpl(
30 const LocationUpdateCallback& callback)
31 : callback_(callback),
32 provider_callback_(
33 base::Bind(&LocationArbitratorImpl::LocationUpdateAvailable,
34 base::Unretained(this))),
35 position_provider_(NULL),
36 is_permission_granted_(false),
37 is_running_(false) {
38 }
39
~LocationArbitratorImpl()40 LocationArbitratorImpl::~LocationArbitratorImpl() {
41 }
42
DefaultNetworkProviderURL()43 GURL LocationArbitratorImpl::DefaultNetworkProviderURL() {
44 return GURL(kDefaultNetworkProviderUrl);
45 }
46
OnPermissionGranted()47 void LocationArbitratorImpl::OnPermissionGranted() {
48 is_permission_granted_ = true;
49 for (ScopedVector<LocationProvider>::iterator i = providers_.begin();
50 i != providers_.end(); ++i) {
51 (*i)->OnPermissionGranted();
52 }
53 }
54
StartProviders(bool use_high_accuracy)55 void LocationArbitratorImpl::StartProviders(bool use_high_accuracy) {
56 // Stash options as OnAccessTokenStoresLoaded has not yet been called.
57 is_running_ = true;
58 use_high_accuracy_ = use_high_accuracy;
59 if (providers_.empty()) {
60 DCHECK(DefaultNetworkProviderURL().is_valid());
61 GetAccessTokenStore()->LoadAccessTokens(
62 base::Bind(&LocationArbitratorImpl::OnAccessTokenStoresLoaded,
63 base::Unretained(this)));
64 } else {
65 DoStartProviders();
66 }
67 }
68
DoStartProviders()69 void LocationArbitratorImpl::DoStartProviders() {
70 for (ScopedVector<LocationProvider>::iterator i = providers_.begin();
71 i != providers_.end(); ++i) {
72 (*i)->StartProvider(use_high_accuracy_);
73 }
74 }
75
StopProviders()76 void LocationArbitratorImpl::StopProviders() {
77 // Reset the reference location state (provider+position)
78 // so that future starts use fresh locations from
79 // the newly constructed providers.
80 position_provider_ = NULL;
81 position_ = Geoposition();
82
83 providers_.clear();
84 is_running_ = false;
85 }
86
OnAccessTokenStoresLoaded(AccessTokenStore::AccessTokenSet access_token_set,net::URLRequestContextGetter * context_getter)87 void LocationArbitratorImpl::OnAccessTokenStoresLoaded(
88 AccessTokenStore::AccessTokenSet access_token_set,
89 net::URLRequestContextGetter* context_getter) {
90 if (!is_running_ || !providers_.empty()) {
91 // A second StartProviders() call may have arrived before the first
92 // completed.
93 return;
94 }
95 // If there are no access tokens, boot strap it with the default server URL.
96 if (access_token_set.empty())
97 access_token_set[DefaultNetworkProviderURL()];
98 for (AccessTokenStore::AccessTokenSet::iterator i =
99 access_token_set.begin();
100 i != access_token_set.end(); ++i) {
101 RegisterProvider(
102 NewNetworkLocationProvider(
103 GetAccessTokenStore(), context_getter,
104 i->first, i->second));
105 }
106
107 LocationProvider* provider =
108 GetContentClient()->browser()->OverrideSystemLocationProvider();
109 if (!provider)
110 provider = NewSystemLocationProvider();
111 RegisterProvider(provider);
112 DoStartProviders();
113 }
114
RegisterProvider(LocationProvider * provider)115 void LocationArbitratorImpl::RegisterProvider(
116 LocationProvider* provider) {
117 if (!provider)
118 return;
119 provider->SetUpdateCallback(provider_callback_);
120 if (is_permission_granted_)
121 provider->OnPermissionGranted();
122 providers_.push_back(provider);
123 }
124
LocationUpdateAvailable(const LocationProvider * provider,const Geoposition & new_position)125 void LocationArbitratorImpl::LocationUpdateAvailable(
126 const LocationProvider* provider,
127 const Geoposition& new_position) {
128 DCHECK(new_position.Validate() ||
129 new_position.error_code != Geoposition::ERROR_CODE_NONE);
130 if (!IsNewPositionBetter(position_, new_position,
131 provider == position_provider_))
132 return;
133 position_provider_ = provider;
134 position_ = new_position;
135 callback_.Run(position_);
136 }
137
NewAccessTokenStore()138 AccessTokenStore* LocationArbitratorImpl::NewAccessTokenStore() {
139 return GetContentClient()->browser()->CreateAccessTokenStore();
140 }
141
GetAccessTokenStore()142 AccessTokenStore* LocationArbitratorImpl::GetAccessTokenStore() {
143 if (!access_token_store_.get())
144 access_token_store_ = NewAccessTokenStore();
145 return access_token_store_.get();
146 }
147
NewNetworkLocationProvider(AccessTokenStore * access_token_store,net::URLRequestContextGetter * context,const GURL & url,const base::string16 & access_token)148 LocationProvider* LocationArbitratorImpl::NewNetworkLocationProvider(
149 AccessTokenStore* access_token_store,
150 net::URLRequestContextGetter* context,
151 const GURL& url,
152 const base::string16& access_token) {
153 #if defined(OS_ANDROID)
154 // Android uses its own SystemLocationProvider.
155 return NULL;
156 #else
157 return new NetworkLocationProvider(access_token_store, context, url,
158 access_token);
159 #endif
160 }
161
NewSystemLocationProvider()162 LocationProvider* LocationArbitratorImpl::NewSystemLocationProvider() {
163 #if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
164 return NULL;
165 #else
166 return content::NewSystemLocationProvider();
167 #endif
168 }
169
GetTimeNow() const170 base::Time LocationArbitratorImpl::GetTimeNow() const {
171 return base::Time::Now();
172 }
173
IsNewPositionBetter(const Geoposition & old_position,const Geoposition & new_position,bool from_same_provider) const174 bool LocationArbitratorImpl::IsNewPositionBetter(
175 const Geoposition& old_position, const Geoposition& new_position,
176 bool from_same_provider) const {
177 // Updates location_info if it's better than what we currently have,
178 // or if it's a newer update from the same provider.
179 if (!old_position.Validate()) {
180 // Older location wasn't locked.
181 return true;
182 }
183 if (new_position.Validate()) {
184 // New location is locked, let's check if it's any better.
185 if (old_position.accuracy >= new_position.accuracy) {
186 // Accuracy is better.
187 return true;
188 } else if (from_same_provider) {
189 // Same provider, fresher location.
190 return true;
191 } else if ((GetTimeNow() - old_position.timestamp).InMilliseconds() >
192 kFixStaleTimeoutMilliseconds) {
193 // Existing fix is stale.
194 return true;
195 }
196 }
197 return false;
198 }
199
HasPermissionBeenGranted() const200 bool LocationArbitratorImpl::HasPermissionBeenGranted() const {
201 return is_permission_granted_;
202 }
203
204 } // namespace content
205