gecko-dev/dom/power/WakeLockSentinel.h
2023-12-05 23:58:07 +00:00

80 lines
2.1 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef DOM_WAKELOCKSENTINEL_H_
#define DOM_WAKELOCKSENTINEL_H_
#include "js/TypeDecls.h"
#include "mozilla/Attributes.h"
#include "mozilla/DOMEventTargetHelper.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/dom/WakeLockBinding.h"
namespace mozilla::dom {
class Promise;
} // namespace mozilla::dom
namespace mozilla::dom {
class WakeLockSentinel final : public DOMEventTargetHelper {
public:
WakeLockSentinel(nsIGlobalObject* aOwnerWindow, WakeLockType aType)
: DOMEventTargetHelper(aOwnerWindow),
mType(aType),
mCreationTime(TimeStamp::Now()) {}
protected:
~WakeLockSentinel() {
MOZ_DIAGNOSTIC_ASSERT(mReleased);
MOZ_DIAGNOSTIC_ASSERT(!mHoldsActualLock);
}
public:
JSObject* WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) override;
bool Released() const;
WakeLockType Type() const { return mType; }
MOZ_CAN_RUN_SCRIPT
already_AddRefed<Promise> ReleaseLock(ErrorResult& aRv);
MOZ_CAN_RUN_SCRIPT
void NotifyLockReleased();
IMPL_EVENT_HANDLER(release);
// Acquire underlying system wake lock by modifying the HAL wake lock counter
void AcquireActualLock();
private:
WakeLockType mType;
bool mReleased = false;
/**
* To avoid user fingerprinting, WakeLockJS::Request will provide a
* WakeLockSentinel even if the lock type is not applicable or cannot be
* obtained.
* But when releasing this sentinel, we have to know whether
* AcquireActualLock was called.
*
* https://w3c.github.io/screen-wake-lock/#dfn-applicable-wake-lock
* https://w3c.github.io/screen-wake-lock/#the-request-method
*/
bool mHoldsActualLock = false;
// Time when this object was created
TimeStamp mCreationTime;
};
} // namespace mozilla::dom
#endif // DOM_WAKELOCKSENTINEL_H_