gecko-dev/layout/base/nsRefreshObservers.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */
/*
* Code to notify things that animate before a refresh, at an appropriate
* refresh rate. (Perhaps temporary, until replaced by compositor.)
*/
#ifndef LAYOUT_BASE_NSREFRESHOBSERVERS_H_
#define LAYOUT_BASE_NSREFRESHOBSERVERS_H_
#include <functional>
#include "mozilla/Attributes.h"
#include "mozilla/TimeStamp.h"
#include "nsISupports.h"
namespace mozilla {
class AnimationEventDispatcher;
class PendingFullscreenEvent;
class PresShell;
class RefreshDriverTimer;
} // namespace mozilla
/**
* An abstract base class to be implemented by callers wanting to be
* notified at refresh times. When nothing needs to be painted, callers
* may not be notified.
*/
class nsARefreshObserver {
public:
// AddRef and Release signatures that match nsISupports. Implementors
// must implement reference counting, and those that do implement
// nsISupports will already have methods with the correct signature.
//
// The refresh driver does NOT hold references to refresh observers
// except while it is notifying them.
NS_INLINE_DECL_PURE_VIRTUAL_REFCOUNTING
MOZ_CAN_RUN_SCRIPT virtual void WillRefresh(mozilla::TimeStamp aTime) = 0;
};
/**
* An abstract base class to be implemented by callers wanting to be notified
* when the observing refresh driver updated mMostRecentRefresh due to active
* timer changes. Callers must ensure an observer is removed before it is
* destroyed.
*/
class nsATimerAdjustmentObserver {
public:
virtual void NotifyTimerAdjusted(mozilla::TimeStamp aTime) = 0;
};
/**
* An abstract base class to be implemented by callers wanting to be notified
* that a refresh has occurred. Callers must ensure an observer is removed
* before it is destroyed.
*/
class nsAPostRefreshObserver {
public:
virtual void DidRefresh() = 0;
};
namespace mozilla {
/**
* A wrapper for nsAPostRefreshObserver that's one-shot (unregisters itself
* after firing once) and can be used without writing a derived class by passing
* in the action in the form of a lambda (or other function object).
*
* Note, while the observer unregisters itself, the registering still needs to
* be done by the caller.
*/
class OneShotPostRefreshObserver : public nsAPostRefreshObserver {
public:
using Action =
std::function<void(mozilla::PresShell*, OneShotPostRefreshObserver*)>;
NS_INLINE_DECL_REFCOUNTING(OneShotPostRefreshObserver)
OneShotPostRefreshObserver(mozilla::PresShell* aPresShell, Action&& aAction);
explicit OneShotPostRefreshObserver(mozilla::PresShell* aPresShell);
void DidRefresh() override;
protected:
virtual ~OneShotPostRefreshObserver();
RefPtr<mozilla::PresShell> mPresShell;
Action mAction;
};
} // namespace mozilla
#endif