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#ifndef CONTENT_PUBLIC_BROWSER_POWER_SAVE_BLOCKER_H_ 6#define CONTENT_PUBLIC_BROWSER_POWER_SAVE_BLOCKER_H_ 7 8#include <string> 9 10#include "base/basictypes.h" 11#include "base/memory/scoped_ptr.h" 12#include "content/common/content_export.h" 13 14namespace content { 15 16// A RAII-style class to block the system from entering low-power (sleep) mode. 17// This class is thread-safe; it may be constructed and deleted on any thread. 18class CONTENT_EXPORT PowerSaveBlocker { 19 public: 20 enum PowerSaveBlockerType { 21 // Prevent the application from being suspended. On some platforms, apps may 22 // be suspended when they are not visible to the user. This type of block 23 // requests that the app continue to run in that case, and on all platforms 24 // prevents the system from sleeping. 25 // Example use cases: downloading a file, playing audio. 26 kPowerSaveBlockPreventAppSuspension, 27 28 // Prevent the display from going to sleep. This also has the side effect of 29 // preventing the system from sleeping, but does not necessarily prevent the 30 // app from being suspended on some platforms if the user hides it. 31 // Example use case: playing video. 32 kPowerSaveBlockPreventDisplaySleep, 33 }; 34 35 virtual ~PowerSaveBlocker() = 0; 36 37 // Pass in the type of power save blocking desired. If multiple types of 38 // blocking are desired, instantiate one PowerSaveBlocker for each type. 39 // |reason| may be provided to the underlying system APIs on some platforms. 40 static scoped_ptr<PowerSaveBlocker> Create(PowerSaveBlockerType type, 41 const std::string& reason); 42}; 43 44} // namespace content 45 46#endif // CONTENT_PUBLIC_BROWSER_POWER_SAVE_BLOCKER_H_ 47