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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <string>
#include "base/basictypes.h"
#include "base/memory/scoped_ptr.h"
#include "content/common/content_export.h"
namespace content {
// A RAII-style class to block the system from entering low-power (sleep) mode.
// This class is thread-safe; it may be constructed and deleted on any thread.
class CONTENT_EXPORT PowerSaveBlocker {
enum PowerSaveBlockerType {
// Prevent the application from being suspended. On some platforms, apps may
// be suspended when they are not visible to the user. This type of block
// requests that the app continue to run in that case, and on all platforms
// prevents the system from sleeping.
// Example use cases: downloading a file, playing audio.
// Prevent the display from going to sleep. This also has the side effect of
// preventing the system from sleeping, but does not necessarily prevent the
// app from being suspended on some platforms if the user hides it.
// Example use case: playing video.
// Reasons why power-saving features may be blocked.
enum Reason {
// Audio is being played.
// Video is being played.
// Power-saving is blocked for some other reason.
virtual ~PowerSaveBlocker() = 0;
// Pass in the type of power save blocking desired. If multiple types of
// blocking are desired, instantiate one PowerSaveBlocker for each type.
// |reason| and |description| (a more-verbose, human-readable justification of
// the blocking) may be provided to the underlying system APIs on some
// platforms.
static scoped_ptr<PowerSaveBlocker> Create(PowerSaveBlockerType type,
Reason reason,
const std::string& description);
} // namespace content