gecko-dev/layout/style/nsAnimationManager.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/. */
#ifndef nsAnimationManager_h_
#define nsAnimationManager_h_
#include "mozilla/Attributes.h"
#include "mozilla/ContentEvents.h"
#include "mozilla/EventForwards.h"
#include "AnimationCommon.h"
#include "mozilla/dom/Animation.h"
#include "mozilla/Keyframe.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/TimeStamp.h"
#include "nsISupportsImpl.h"
class nsIGlobalObject;
class ServoComputedData;
struct nsStyleDisplay;
class ServoCSSAnimationBuilder;
namespace mozilla {
class ComputedStyle;
namespace css {
class Declaration;
} /* namespace css */
namespace dom {
class Promise;
} /* namespace dom */
enum class CSSPseudoElementType : uint8_t;
struct NonOwningAnimationTarget;
namespace dom {
class CSSAnimation final : public Animation
{
public:
explicit CSSAnimation(nsIGlobalObject* aGlobal,
nsAtom* aAnimationName)
: dom::Animation(aGlobal)
, mAnimationName(aAnimationName)
, mIsStylePaused(false)
, mPauseShouldStick(false)
, mNeedsNewAnimationIndexWhenRun(false)
, mPreviousPhase(ComputedTiming::AnimationPhase::Idle)
, mPreviousIteration(0)
{
// We might need to drop this assertion once we add a script-accessible
// constructor but for animations generated from CSS markup the
// animation-name should never be empty.
MOZ_ASSERT(mAnimationName != nsGkAtoms::_empty,
"animation-name should not be 'none'");
}
JSObject* WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) override;
CSSAnimation* AsCSSAnimation() override { return this; }
const CSSAnimation* AsCSSAnimation() const override { return this; }
// CSSAnimation interface
void GetAnimationName(nsString& aRetVal) const
{
mAnimationName->ToString(aRetVal);
}
nsAtom* AnimationName() const { return mAnimationName; }
// Animation interface overrides
virtual Promise* GetReady(ErrorResult& aRv) override;
virtual void Play(ErrorResult& aRv, LimitBehavior aLimitBehavior) override;
virtual void Pause(ErrorResult& aRv) override;
// NOTE: tabbrowser.xml currently relies on the fact that reading the
// currentTime of a CSSAnimation does *not* flush style (whereas reading the
// playState does). If CSS Animations 2 specifies that reading currentTime
// also flushes style we will need to find another way to detect canceled
// animations in tabbrowser.xml. On the other hand, if CSS Animations 2
// specifies that reading playState does *not* flush style (and we drop the
// following override), then we should update tabbrowser.xml to check
// the playState instead.
AnimationPlayState PlayStateFromJS() const override;
bool PendingFromJS() const override;
void PlayFromJS(ErrorResult& aRv) override;
void PlayFromStyle();
void PauseFromStyle();
void CancelFromStyle() override
{
// When an animation is disassociated with style it enters an odd state
// where its composite order is undefined until it first transitions
// out of the idle state.
//
// Even if the composite order isn't defined we don't want it to be random
// in case we need to determine the order to dispatch events associated
// with an animation in this state. To solve this we treat the animation as
// if it had been added to the end of the global animation list so that
// its sort order is defined. We'll update this index again once the
// animation leaves the idle state.
mAnimationIndex = sNextAnimationIndex++;
mNeedsNewAnimationIndexWhenRun = true;
Animation::CancelFromStyle();
// We need to do this *after* calling CancelFromStyle() since
// CancelFromStyle might synchronously trigger a cancel event for which
// we need an owning element to target the event at.
mOwningElement = OwningElementRef();
}
void Tick() override;
void QueueEvents(const StickyTimeDuration& aActiveTime = StickyTimeDuration());
bool IsStylePaused() const { return mIsStylePaused; }
bool HasLowerCompositeOrderThan(const CSSAnimation& aOther) const;
void SetAnimationIndex(uint64_t aIndex)
{
MOZ_ASSERT(IsTiedToMarkup());
if (IsRelevant() &&
mAnimationIndex != aIndex) {
nsNodeUtils::AnimationChanged(this);
PostUpdate();
}
mAnimationIndex = aIndex;
}
// Sets the owning element which is used for determining the composite
// order of CSSAnimation objects generated from CSS markup.
//
// @see mOwningElement
void SetOwningElement(const OwningElementRef& aElement)
{
mOwningElement = aElement;
}
// True for animations that are generated from CSS markup and continue to
// reflect changes to that markup.
bool IsTiedToMarkup() const { return mOwningElement.IsSet(); }
void MaybeQueueCancelEvent(const StickyTimeDuration& aActiveTime) override {
QueueEvents(aActiveTime);
}
protected:
virtual ~CSSAnimation()
{
MOZ_ASSERT(!mOwningElement.IsSet(), "Owning element should be cleared "
"before a CSS animation is destroyed");
}
// Animation overrides
void UpdateTiming(SeekFlag aSeekFlag,
SyncNotifyFlag aSyncNotifyFlag) override;
// Returns the duration from the start of the animation's source effect's
// active interval to the point where the animation actually begins playback.
// This is zero unless the animation's source effect has a negative delay in
// which case it is the absolute value of that delay.
// This is used for setting the elapsedTime member of CSS AnimationEvents.
TimeDuration InitialAdvance() const {
return mEffect ?
std::max(TimeDuration(), mEffect->SpecifiedTiming().Delay() * -1) :
TimeDuration();
}
RefPtr<nsAtom> mAnimationName;
// The (pseudo-)element whose computed animation-name refers to this
// animation (if any).
//
// This is used for determining the relative composite order of animations
// generated from CSS markup.
//
// Typically this will be the same as the target element of the keyframe
// effect associated with this animation. However, it can differ in the
// following circumstances:
//
// a) If script removes or replaces the effect of this animation,
// b) If this animation is cancelled (e.g. by updating the
// animation-name property or removing the owning element from the
// document),
// c) If this object is generated from script using the CSSAnimation
// constructor.
//
// For (b) and (c) the owning element will return !IsSet().
OwningElementRef mOwningElement;
// When combining animation-play-state with play() / pause() the following
// behavior applies:
// 1. pause() is sticky and always overrides the underlying
// animation-play-state
// 2. If animation-play-state is 'paused', play() will temporarily override
// it until animation-play-state next becomes 'running'.
// 3. Calls to play() trigger finishing behavior but setting the
// animation-play-state to 'running' does not.
//
// This leads to five distinct states:
//
// A. Running
// B. Running and temporarily overriding animation-play-state: paused
// C. Paused and sticky overriding animation-play-state: running
// D. Paused and sticky overriding animation-play-state: paused
// E. Paused by animation-play-state
//
// C and D may seem redundant but they differ in how to respond to the
// sequence: call play(), set animation-play-state: paused.
//
// C will transition to A then E leaving the animation paused.
// D will transition to B then B leaving the animation running.
//
// A state transition chart is as follows:
//
// A | B | C | D | E
// ---------------------------
// play() A | B | A | B | B
// pause() C | D | C | D | D
// 'running' A | A | C | C | A
// 'paused' E | B | D | D | E
//
// The base class, Animation already provides a boolean value,
// mIsPaused which gives us two states. To this we add a further two booleans
// to represent the states as follows.
//
// A. Running
// (!mIsPaused; !mIsStylePaused; !mPauseShouldStick)
// B. Running and temporarily overriding animation-play-state: paused
// (!mIsPaused; mIsStylePaused; !mPauseShouldStick)
// C. Paused and sticky overriding animation-play-state: running
// (mIsPaused; !mIsStylePaused; mPauseShouldStick)
// D. Paused and sticky overriding animation-play-state: paused
// (mIsPaused; mIsStylePaused; mPauseShouldStick)
// E. Paused by animation-play-state
// (mIsPaused; mIsStylePaused; !mPauseShouldStick)
//
// (That leaves 3 combinations of the boolean values that we never set because
// they don't represent valid states.)
bool mIsStylePaused;
bool mPauseShouldStick;
// When true, indicates that when this animation next leaves the idle state,
// its animation index should be updated.
bool mNeedsNewAnimationIndexWhenRun;
// Phase and current iteration from the previous time we queued events.
// This is used to determine what new events to dispatch.
ComputedTiming::AnimationPhase mPreviousPhase;
uint64_t mPreviousIteration;
};
} /* namespace dom */
template <>
struct AnimationTypeTraits<dom::CSSAnimation>
{
static nsAtom* ElementPropertyAtom()
{
return nsGkAtoms::animationsProperty;
}
static nsAtom* BeforePropertyAtom()
{
return nsGkAtoms::animationsOfBeforeProperty;
}
static nsAtom* AfterPropertyAtom()
{
return nsGkAtoms::animationsOfAfterProperty;
}
};
} /* namespace mozilla */
class nsAnimationManager final
: public mozilla::CommonAnimationManager<mozilla::dom::CSSAnimation>
{
public:
explicit nsAnimationManager(nsPresContext *aPresContext)
: mozilla::CommonAnimationManager<mozilla::dom::CSSAnimation>(aPresContext)
{
}
typedef mozilla::AnimationCollection<mozilla::dom::CSSAnimation>
CSSAnimationCollection;
typedef nsTArray<RefPtr<mozilla::dom::CSSAnimation>>
OwningCSSAnimationPtrArray;
~nsAnimationManager() override = default;
/**
* This function does the same thing as the above UpdateAnimations()
* but with servo's computed values.
*/
void UpdateAnimations(
mozilla::dom::Element* aElement,
mozilla::CSSPseudoElementType aPseudoType,
const mozilla::ComputedStyle* aComputedValues);
// Utility function to walk through |aIter| to find the Keyframe with
// matching offset and timing function but stopping as soon as the offset
// differs from |aOffset| (i.e. it assumes a sorted iterator).
//
// If a matching Keyframe is found,
// Returns true and sets |aIndex| to the index of the matching Keyframe
// within |aIter|.
//
// If no matching Keyframe is found,
// Returns false and sets |aIndex| to the index in the iterator of the
// first Keyframe with an offset differing to |aOffset| or, if the end
// of the iterator is reached, sets |aIndex| to the index after the last
// Keyframe.
template <class IterType, class TimingFunctionType>
static bool FindMatchingKeyframe(
IterType&& aIter,
double aOffset,
const TimingFunctionType& aTimingFunctionToMatch,
size_t& aIndex)
{
aIndex = 0;
for (mozilla::Keyframe& keyframe : aIter) {
if (keyframe.mOffset.value() != aOffset) {
break;
}
if (keyframe.mTimingFunction == aTimingFunctionToMatch) {
return true;
}
++aIndex;
}
return false;
}
bool AnimationMayBeReferenced(nsAtom* aName) const
{
return mMaybeReferencedAnimations.Contains(aName);
}
private:
// This includes all animation names referenced regardless of whether a
// corresponding `@keyframes` rule is available.
//
// It may contain names which are no longer referenced, but it should always
// contain names which are currently referenced, so that it is usable for
// style invalidation.
nsTHashtable<nsRefPtrHashKey<nsAtom>> mMaybeReferencedAnimations;
void DoUpdateAnimations(
const mozilla::NonOwningAnimationTarget& aTarget,
const nsStyleDisplay& aStyleDisplay,
ServoCSSAnimationBuilder& aBuilder);
};
#endif /* !defined(nsAnimationManager_h_) */