SystemMonitor refactoring: move power state monitor into a separate class called PowerMonitor

base/power_monitor/power_monitor.cc

Index: base/power_monitor/power_monitor.cc
diff --git a/base/system_monitor/system_monitor.cc b/base/power_monitor/power_monitor.cc
similarity index 28%
copy from base/system_monitor/system_monitor.cc
copy to base/power_monitor/power_monitor.cc
index 2616275dfbc64db88abaa6abb0fa85e8cf561a7d..0241dfe1e6503aae37e30222b512890f880949a0 100644
--- a/base/system_monitor/system_monitor.cc
+++ b/base/power_monitor/power_monitor.cc
@@ -2,19 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/system_monitor/system_monitor.h"
-
-#include <utility>
-
-#include "base/logging.h"
-#include "base/message_loop.h"
-#include "base/stl_util.h"
-#include "base/time.h"
-#include "base/utf_string_conversions.h"
+#include "base/power_monitor/power_monitor.h"
 
 namespace base {
 
-static SystemMonitor* g_system_monitor = NULL;
+static PowerMonitor* g_power_monitor = NULL;
 
 #if defined(ENABLE_BATTERY_MONITORING)
 // The amount of time (in ms) to wait before running the initial
@@ -22,52 +14,58 @@ static SystemMonitor* g_system_monitor = NULL;
 static int kDelayedBatteryCheckMs = 10 * 1000;
 #endif  // defined(ENABLE_BATTERY_MONITORING)
 
-SystemMonitor::RemovableStorageInfo::RemovableStorageInfo() {
-}
-
-SystemMonitor::RemovableStorageInfo::RemovableStorageInfo(
-    const std::string& id,
-    const string16& device_name,
-    const FilePath::StringType& device_location)
-    : device_id(id),
-      name(device_name),
-      location(device_location) {
-}
-
-SystemMonitor::SystemMonitor()
-    : power_observer_list_(new ObserverListThreadSafe<PowerObserver>()),
-      devices_changed_observer_list_(
-          new ObserverListThreadSafe<DevicesChangedObserver>()),
+PowerMonitor::PowerMonitor()
+    : observers_(new ObserverListThreadSafe<PowerObserver>()),
       battery_in_use_(false),
-      suspended_(false) {
-  DCHECK(!g_system_monitor);
-  g_system_monitor = this;
+      suspended_(false),
+      signaler_available_(true)  {
+  DCHECK(!g_power_monitor);
+  g_power_monitor = this;
 
   DCHECK(MessageLoop::current());
 #if defined(ENABLE_BATTERY_MONITORING)
   delayed_battery_check_.Start(FROM_HERE,
       base::TimeDelta::FromMilliseconds(kDelayedBatteryCheckMs), this,
-      &SystemMonitor::BatteryCheck);
+      &PowerMonitor::BatteryCheck);
 #endif  // defined(ENABLE_BATTERY_MONITORING)
+
 #if defined(OS_MACOSX)
   PlatformInit();
 #endif
 }
 
-SystemMonitor::~SystemMonitor() {
+PowerMonitor::~PowerMonitor() {
 #if defined(OS_MACOSX)
   PlatformDestroy();
 #endif
-  DCHECK_EQ(this, g_system_monitor);
-  g_system_monitor = NULL;
+  DCHECK_EQ(this, g_power_monitor);
+  g_power_monitor = NULL;
 }
 
 // static
-SystemMonitor* SystemMonitor::Get() {
-  return g_system_monitor;
+PowerMonitor* PowerMonitor::Get() {
+  return g_power_monitor;
+}
+
+PowerMonitor::Signaler* PowerMonitor::GetSignalerOnce() {
+ if (signaler_available_) {
+   signaler_available_ = false;
+   return new PowerMonitor::Signaler();
+  }
+
+  // Return NULL after the first time it get called.
+  return NULL;
 }
 
-void SystemMonitor::ProcessPowerMessage(PowerEvent event_id) {
+void PowerMonitor::AddObserver(PowerObserver* obs) {
+  observers_->AddObserver(obs);
+}
+
+void PowerMonitor::RemoveObserver(PowerObserver* obs) {
+  observers_->RemoveObserver(obs);
+}
+
+void PowerMonitor::ProcessPowerEvent(PowerEvent event_id) {
   // Suppress duplicate notifications.  Some platforms may
   // send multiple notifications of the same event.
   switch (event_id) {
@@ -95,108 +93,46 @@ void SystemMonitor::ProcessPowerMessage(PowerEvent event_id) {
   }
 }
 
-void SystemMonitor::ProcessDevicesChanged(DeviceType device_type) {
-  NotifyDevicesChanged(device_type);
-}
-
-void SystemMonitor::ProcessRemovableStorageAttached(
-    const std::string& id,
-    const string16& name,
-    const FilePath::StringType& location) {
-  {
-    base::AutoLock lock(removable_storage_lock_);
-    if (ContainsKey(removable_storage_map_, id)) {
-      // This can happen if our unique id scheme fails. Ignore the incoming
-      // non-unique attachment.
-      return;
-    }
-    RemovableStorageInfo info(id, name, location);
-    removable_storage_map_.insert(std::make_pair(id, info));
-  }
-  NotifyRemovableStorageAttached(id, name, location);
-}
-
-void SystemMonitor::ProcessRemovableStorageDetached(const std::string& id) {
-  {
-    base::AutoLock lock(removable_storage_lock_);
-    RemovableStorageMap::iterator it = removable_storage_map_.find(id);
-    if (it == removable_storage_map_.end())
-      return;
-    removable_storage_map_.erase(it);
-  }
-  NotifyRemovableStorageDetached(id);
-}
-
-std::vector<SystemMonitor::RemovableStorageInfo>
-SystemMonitor::GetAttachedRemovableStorage() const {
-  std::vector<RemovableStorageInfo> results;
-
-  base::AutoLock lock(removable_storage_lock_);
-  for (RemovableStorageMap::const_iterator it = removable_storage_map_.begin();
-       it != removable_storage_map_.end();
-       ++it) {
-    results.push_back(it->second);
-  }
-  return results;
-}
-
-void SystemMonitor::AddPowerObserver(PowerObserver* obs) {
-  power_observer_list_->AddObserver(obs);
-}
-
-void SystemMonitor::RemovePowerObserver(PowerObserver* obs) {
-  power_observer_list_->RemoveObserver(obs);
-}
-
-void SystemMonitor::AddDevicesChangedObserver(DevicesChangedObserver* obs) {
-  devices_changed_observer_list_->AddObserver(obs);
+void PowerMonitor::NotifyPowerStateChange() {
+  DVLOG(1) << "PowerStateChange: " << (BatteryPower() ? "On" : "Off")
+           << " battery";
+  observers_->Notify(&PowerObserver::OnPowerStateChange,
+                               BatteryPower());
 }
 
-void SystemMonitor::RemoveDevicesChangedObserver(DevicesChangedObserver* obs) {
-  devices_changed_observer_list_->RemoveObserver(obs);
+void PowerMonitor::NotifySuspend() {
+  DVLOG(1) << "Power Suspending";
+  observers_->Notify(&PowerObserver::OnSuspend);
 }
 
-void SystemMonitor::NotifyDevicesChanged(DeviceType device_type) {
-  DVLOG(1) << "DevicesChanged with device type " << device_type;
-  devices_changed_observer_list_->Notify(
-      &DevicesChangedObserver::OnDevicesChanged, device_type);
+void PowerMonitor::NotifyResume() {
+  DVLOG(1) << "Power Resuming";
+  observers_->Notify(&PowerObserver::OnResume);
 }
 
-void SystemMonitor::NotifyRemovableStorageAttached(
-    const std::string& id,
-    const string16& name,
-    const FilePath::StringType& location) {
-  DVLOG(1) << "RemovableStorageAttached with name " << UTF16ToUTF8(name)
-           << " and id " << id;
-  devices_changed_observer_list_->Notify(
-    &DevicesChangedObserver::OnRemovableStorageAttached, id, name, location);
+void PowerMonitor::BatteryCheck() {
+  ProcessPowerEvent(PowerMonitor::POWER_STATE_EVENT);
 }
 
-void SystemMonitor::NotifyRemovableStorageDetached(const std::string& id) {
-  DVLOG(1) << "RemovableStorageDetached for id " << id;
-  devices_changed_observer_list_->Notify(
-    &DevicesChangedObserver::OnRemovableStorageDetached, id);
-}
+// PowerMonitor::Signaler
 
-void SystemMonitor::NotifyPowerStateChange() {
-  DVLOG(1) << "PowerStateChange: " << (BatteryPower() ? "On" : "Off")
-           << " battery";
-  power_observer_list_->Notify(&PowerObserver::OnPowerStateChange,
-                               BatteryPower());
+PowerMonitor::Signaler::Signaler() {
 }
 
-void SystemMonitor::NotifySuspend() {
-  DVLOG(1) << "Power Suspending";
-  power_observer_list_->Notify(&PowerObserver::OnSuspend);
+PowerMonitor::Signaler::~Signaler() {
 }
 
-void SystemMonitor::NotifyResume() {
-  DVLOG(1) << "Power Resuming";
-  power_observer_list_->Notify(&PowerObserver::OnResume);
+#if defined(OS_WIN)
+void PowerMonitor::Signaler::ProcessWmPowerBroadcastMessage(int event) {
+  if (PowerMonitor::Get())
+    PowerMonitor::Get()->ProcessWmPowerBroadcastMessage(event);
 }
+#endif
 
-void SystemMonitor::BatteryCheck() {
-  ProcessPowerMessage(SystemMonitor::POWER_STATE_EVENT);
+void PowerMonitor::Signaler::ProcessPowerEvent(PowerEvent event) {
+  if (PowerMonitor::Get())
+    PowerMonitor::Get()->ProcessPowerEvent(event);
 }
 
 }  // namespace base
+