src/extensions/browser/api/system_info/system_info_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 "extensions/browser/api/system_info/system_info_api.h"
   6
   7 #include <set>
   8
   9 #include "base/bind.h"
  10 #include "base/lazy_instance.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/memory/singleton.h"
  13 #include "base/strings/string_util.h"
  14 #include "base/values.h"
  15 #include "components/storage_monitor/removable_storage_observer.h"
  16 #include "components/storage_monitor/storage_info.h"
  17 #include "components/storage_monitor/storage_monitor.h"
  18 #include "content/public/browser/browser_thread.h"
  19 #include "extensions/browser/api/system_display/display_info_provider.h"
  20 #include "extensions/browser/api/system_storage/storage_info_provider.h"
  21 #include "extensions/browser/extensions_browser_client.h"
  22 #include "extensions/common/api/system_display.h"
  23 #include "extensions/common/api/system_storage.h"
  24 #include "ui/gfx/display_observer.h"
  25 #include "ui/gfx/screen.h"
  26
  27 namespace extensions {
  28
  29 using core_api::system_storage::StorageUnitInfo;
  30 using content::BrowserThread;
  31 using storage_monitor::StorageMonitor;
  32
  33 namespace system_display = core_api::system_display;
  34 namespace system_storage = core_api::system_storage;
  35
  36 namespace {
  37
  38 bool IsDisplayChangedEvent(const std::string& event_name) {
  39   return event_name == system_display::OnDisplayChanged::kEventName;
  40 }
  41
  42 bool IsSystemStorageEvent(const std::string& event_name) {
  43   return (event_name == system_storage::OnAttached::kEventName ||
  44           event_name == system_storage::OnDetached::kEventName);
  45 }
  46
  47 // Event router for systemInfo API. It is a singleton instance shared by
  48 // multiple profiles.
  49 class SystemInfoEventRouter : public gfx::DisplayObserver,
  50                               public storage_monitor::RemovableStorageObserver {
  51  public:
  52   static SystemInfoEventRouter* GetInstance();
  53
  54   SystemInfoEventRouter();
  55   virtual ~SystemInfoEventRouter();
  56
  57   // Add/remove event listener for the |event_name| event.
  58   void AddEventListener(const std::string& event_name);
  59   void RemoveEventListener(const std::string& event_name);
  60
  61  private:
  62   // gfx::DisplayObserver:
  63   virtual void OnDisplayAdded(const gfx::Display& new_display) OVERRIDE;
  64   virtual void OnDisplayRemoved(const gfx::Display& old_display) OVERRIDE;
  65   virtual void OnDisplayMetricsChanged(const gfx::Display& display,
  66                                        uint32_t metrics) OVERRIDE;
  67
  68   // RemovableStorageObserver implementation.
  69   virtual void OnRemovableStorageAttached(
  70       const storage_monitor::StorageInfo& info) OVERRIDE;
  71   virtual void OnRemovableStorageDetached(
  72       const storage_monitor::StorageInfo& info) OVERRIDE;
  73
  74   // Called from any thread to dispatch the systemInfo event to all extension
  75   // processes cross multiple profiles.
  76   void DispatchEvent(const std::string& event_name,
  77                      scoped_ptr<base::ListValue> args);
  78
  79   // Called to dispatch the systemInfo.display.onDisplayChanged event.
  80   void OnDisplayChanged();
  81
  82   // Used to record the event names being watched.
  83   std::multiset<std::string> watching_event_set_;
  84
  85   bool has_storage_monitor_observer_;
  86
  87   DISALLOW_COPY_AND_ASSIGN(SystemInfoEventRouter);
  88 };
  89
  90 static base::LazyInstance<SystemInfoEventRouter>::Leaky
  91     g_system_info_event_router = LAZY_INSTANCE_INITIALIZER;
  92
  93 // static
  94 SystemInfoEventRouter* SystemInfoEventRouter::GetInstance() {
  95   return g_system_info_event_router.Pointer();
  96 }
  97
  98 SystemInfoEventRouter::SystemInfoEventRouter()
  99     : has_storage_monitor_observer_(false) {
 100 }
 101
 102 SystemInfoEventRouter::~SystemInfoEventRouter() {
 103   if (has_storage_monitor_observer_) {
 104     StorageMonitor* storage_monitor = StorageMonitor::GetInstance();
 105     if (storage_monitor)
 106       storage_monitor->RemoveObserver(this);
 107   }
 108 }
 109
 110 void SystemInfoEventRouter::AddEventListener(const std::string& event_name) {
 111   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 112
 113   watching_event_set_.insert(event_name);
 114   if (watching_event_set_.count(event_name) > 1)
 115     return;
 116
 117   if (IsDisplayChangedEvent(event_name)) {
 118     gfx::Screen* screen = DisplayInfoProvider::Get()->GetActiveScreen();
 119     if (screen)
 120       screen->AddObserver(this);
 121   }
 122
 123   if (IsSystemStorageEvent(event_name)) {
 124     if (!has_storage_monitor_observer_) {
 125       has_storage_monitor_observer_ = true;
 126       DCHECK(StorageMonitor::GetInstance()->IsInitialized());
 127       StorageMonitor::GetInstance()->AddObserver(this);
 128     }
 129   }
 130 }
 131
 132 void SystemInfoEventRouter::RemoveEventListener(const std::string& event_name) {
 133   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 134
 135   std::multiset<std::string>::iterator it =
 136       watching_event_set_.find(event_name);
 137   if (it != watching_event_set_.end()) {
 138     watching_event_set_.erase(it);
 139     if (watching_event_set_.count(event_name) > 0)
 140       return;
 141   }
 142
 143   if (IsDisplayChangedEvent(event_name)) {
 144     gfx::Screen* screen = DisplayInfoProvider::Get()->GetActiveScreen();
 145     if (screen)
 146       screen->RemoveObserver(this);
 147   }
 148
 149   if (IsSystemStorageEvent(event_name)) {
 150     const std::string& other_event_name =
 151         (event_name == system_storage::OnDetached::kEventName)
 152             ? system_storage::OnAttached::kEventName
 153             : system_storage::OnDetached::kEventName;
 154     if (watching_event_set_.count(other_event_name) == 0) {
 155       StorageMonitor::GetInstance()->RemoveObserver(this);
 156       has_storage_monitor_observer_ = false;
 157     }
 158   }
 159 }
 160
 161 void SystemInfoEventRouter::OnRemovableStorageAttached(
 162     const storage_monitor::StorageInfo& info) {
 163   StorageUnitInfo unit;
 164   systeminfo::BuildStorageUnitInfo(info, &unit);
 165   scoped_ptr<base::ListValue> args(new base::ListValue);
 166   args->Append(unit.ToValue().release());
 167   DispatchEvent(system_storage::OnAttached::kEventName, args.Pass());
 168 }
 169
 170 void SystemInfoEventRouter::OnRemovableStorageDetached(
 171     const storage_monitor::StorageInfo& info) {
 172   scoped_ptr<base::ListValue> args(new base::ListValue);
 173   std::string transient_id =
 174       StorageMonitor::GetInstance()->GetTransientIdForDeviceId(
 175           info.device_id());
 176   args->AppendString(transient_id);
 177
 178   DispatchEvent(system_storage::OnDetached::kEventName, args.Pass());
 179 }
 180
 181 void SystemInfoEventRouter::OnDisplayAdded(const gfx::Display& new_display) {
 182   OnDisplayChanged();
 183 }
 184
 185 void SystemInfoEventRouter::OnDisplayRemoved(const gfx::Display& old_display) {
 186   OnDisplayChanged();
 187 }
 188
 189 void SystemInfoEventRouter::OnDisplayMetricsChanged(const gfx::Display& display,
 190                                                     uint32_t metrics) {
 191   OnDisplayChanged();
 192 }
 193
 194 void SystemInfoEventRouter::OnDisplayChanged() {
 195   scoped_ptr<base::ListValue> args(new base::ListValue());
 196   DispatchEvent(system_display::OnDisplayChanged::kEventName, args.Pass());
 197 }
 198
 199 void SystemInfoEventRouter::DispatchEvent(const std::string& event_name,
 200                                           scoped_ptr<base::ListValue> args) {
 201   ExtensionsBrowserClient::Get()->BroadcastEventToRenderers(event_name,
 202                                                             args.Pass());
 203 }
 204
 205 void AddEventListener(const std::string& event_name) {
 206   SystemInfoEventRouter::GetInstance()->AddEventListener(event_name);
 207 }
 208
 209 void RemoveEventListener(const std::string& event_name) {
 210   SystemInfoEventRouter::GetInstance()->RemoveEventListener(event_name);
 211 }
 212
 213 }  // namespace
 214
 215 static base::LazyInstance<BrowserContextKeyedAPIFactory<SystemInfoAPI> >
 216     g_factory = LAZY_INSTANCE_INITIALIZER;
 217
 218 // static
 219 BrowserContextKeyedAPIFactory<SystemInfoAPI>*
 220 SystemInfoAPI::GetFactoryInstance() {
 221   return g_factory.Pointer();
 222 }
 223
 224 SystemInfoAPI::SystemInfoAPI(content::BrowserContext* context)
 225     : browser_context_(context) {
 226   EventRouter* router = EventRouter::Get(browser_context_);
 227   router->RegisterObserver(this, system_storage::OnAttached::kEventName);
 228   router->RegisterObserver(this, system_storage::OnDetached::kEventName);
 229   router->RegisterObserver(this, system_display::OnDisplayChanged::kEventName);
 230 }
 231
 232 SystemInfoAPI::~SystemInfoAPI() {
 233 }
 234
 235 void SystemInfoAPI::Shutdown() {
 236   EventRouter::Get(browser_context_)->UnregisterObserver(this);
 237 }
 238
 239 void SystemInfoAPI::OnListenerAdded(const EventListenerInfo& details) {
 240   if (IsSystemStorageEvent(details.event_name)) {
 241     StorageMonitor::GetInstance()->EnsureInitialized(
 242         base::Bind(&AddEventListener, details.event_name));
 243   } else {
 244     AddEventListener(details.event_name);
 245   }
 246 }
 247
 248 void SystemInfoAPI::OnListenerRemoved(const EventListenerInfo& details) {
 249   if (IsSystemStorageEvent(details.event_name)) {
 250     StorageMonitor::GetInstance()->EnsureInitialized(
 251         base::Bind(&RemoveEventListener, details.event_name));
 252   } else {
 253     RemoveEventListener(details.event_name);
 254   }
 255 }
 256
 257 }  // namespace extensions