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 14 namespace 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. 18 class 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