extensions/browser/api/power/power_api_manager.cc

   1 // Copyright 2014 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/power/power_api_manager.h"
   6
   7 #include "base/bind.h"
   8 #include "base/lazy_instance.h"
   9 #include "extensions/browser/extension_registry.h"
  10 #include "extensions/common/extension.h"
  11
  12 namespace extensions {
  13
  14 namespace {
  15
  16 const char kPowerSaveBlockerReason[] = "extension";
  17
  18 content::PowerSaveBlocker::PowerSaveBlockerType
  19 LevelToPowerSaveBlockerType(core_api::power::Level level) {
  20   switch (level) {
  21     case core_api::power::LEVEL_SYSTEM:
  22       return content::PowerSaveBlocker::kPowerSaveBlockPreventAppSuspension;
  23     case core_api::power::LEVEL_DISPLAY:  // fallthrough
  24     case core_api::power::LEVEL_NONE:
  25       return content::PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep;
  26   }
  27   NOTREACHED() << "Unhandled level " << level;
  28   return content::PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep;
  29 }
  30
  31 base::LazyInstance<BrowserContextKeyedAPIFactory<PowerApiManager> > g_factory =
  32     LAZY_INSTANCE_INITIALIZER;
  33
  34 }  // namespace
  35
  36 // static
  37 PowerApiManager* PowerApiManager::Get(content::BrowserContext* context) {
  38   return BrowserContextKeyedAPIFactory<PowerApiManager>::Get(context);
  39 }
  40
  41 // static
  42 BrowserContextKeyedAPIFactory<PowerApiManager>*
  43 PowerApiManager::GetFactoryInstance() {
  44   return g_factory.Pointer();
  45 }
  46
  47 void PowerApiManager::AddRequest(const std::string& extension_id,
  48                                  core_api::power::Level level) {
  49   extension_levels_[extension_id] = level;
  50   UpdatePowerSaveBlocker();
  51 }
  52
  53 void PowerApiManager::RemoveRequest(const std::string& extension_id) {
  54   extension_levels_.erase(extension_id);
  55   UpdatePowerSaveBlocker();
  56 }
  57
  58 void PowerApiManager::SetCreateBlockerFunctionForTesting(
  59     CreateBlockerFunction function) {
  60   create_blocker_function_ = !function.is_null() ? function :
  61       base::Bind(&content::PowerSaveBlocker::Create);
  62 }
  63
  64 void PowerApiManager::OnExtensionUnloaded(
  65     content::BrowserContext* browser_context,
  66     const Extension* extension,
  67     UnloadedExtensionInfo::Reason reason) {
  68   RemoveRequest(extension->id());
  69   UpdatePowerSaveBlocker();
  70 }
  71
  72 PowerApiManager::PowerApiManager(content::BrowserContext* context)
  73     : browser_context_(context),
  74       create_blocker_function_(base::Bind(&content::PowerSaveBlocker::Create)),
  75       current_level_(core_api::power::LEVEL_SYSTEM) {
  76   ExtensionRegistry::Get(browser_context_)->AddObserver(this);
  77 }
  78
  79 PowerApiManager::~PowerApiManager() {}
  80
  81 void PowerApiManager::UpdatePowerSaveBlocker() {
  82   if (extension_levels_.empty()) {
  83     power_save_blocker_.reset();
  84     return;
  85   }
  86
  87   core_api::power::Level new_level = core_api::power::LEVEL_SYSTEM;
  88   for (ExtensionLevelMap::const_iterator it = extension_levels_.begin();
  89        it != extension_levels_.end(); ++it) {
  90     if (it->second == core_api::power::LEVEL_DISPLAY)
  91       new_level = it->second;
  92   }
  93
  94   // If the level changed and we need to create a new blocker, do a swap
  95   // to ensure that there isn't a brief period where power management is
  96   // unblocked.
  97   if (!power_save_blocker_ || new_level != current_level_) {
  98     content::PowerSaveBlocker::PowerSaveBlockerType type =
  99         LevelToPowerSaveBlockerType(new_level);
 100     scoped_ptr<content::PowerSaveBlocker> new_blocker(
 101         create_blocker_function_.Run(type, kPowerSaveBlockerReason));
 102     power_save_blocker_.swap(new_blocker);
 103     current_level_ = new_level;
 104   }
 105 }
 106
 107 void PowerApiManager::Shutdown() {
 108   // Unregister here rather than in the d'tor; otherwise this call will recreate
 109   // the already-deleted ExtensionRegistry.
 110   ExtensionRegistry::Get(browser_context_)->RemoveObserver(this);
 111   power_save_blocker_.reset();
 112 }
 113
 114 }  // namespace extensions