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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 */
#ifndef mozilla_dom_CSSAnimation_h
#define mozilla_dom_CSSAnimation_h
#include "mozilla/dom/Animation.h"
#include "mozilla/dom/KeyframeEffect.h"
#include "mozilla/dom/MutationObservers.h"
#include "mozilla/StyleAnimationValue.h"
#include "AnimationCommon.h"
namespace mozilla {
// Properties of CSS Animations that can be overridden by the Web Animations API
// in a manner that means we should ignore subsequent changes to markup for that
// property.
enum class CSSAnimationProperties {
None = 0,
Keyframes = 1 << 0,
Duration = 1 << 1,
IterationCount = 1 << 2,
Direction = 1 << 3,
Delay = 1 << 4,
FillMode = 1 << 5,
Composition = 1 << 6,
Effect = Keyframes | Duration | IterationCount | Direction | Delay |
FillMode | Composition,
PlayState = 1 << 7,
namespace dom {
class CSSAnimation final : public Animation {
explicit CSSAnimation(nsIGlobalObject* aGlobal, nsAtom* aAnimationName)
: dom::Animation(aGlobal),
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 {
nsAtom* AnimationName() const { return mAnimationName; }
// Animation interface overrides
void SetEffect(AnimationEffect* aEffect) override;
void SetStartTimeAsDouble(const Nullable<double>& aStartTime) override;
Promise* GetReady(ErrorResult& aRv) override;
void Reverse(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 PauseFromJS(ErrorResult& aRv) override;
void PlayFromStyle();
void PauseFromStyle();
void CancelFromStyle(PostRestyleMode aPostRestyle) {
// 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;
// We need to do this *after* calling Cancel() since
// Cancel() might synchronously trigger a cancel event for which
// we need an owning element to target the event at.
mOwningElement = OwningElementRef();
void Tick(TickState&) override;
void QueueEvents(
const StickyTimeDuration& aActiveTime = StickyTimeDuration());
bool HasLowerCompositeOrderThan(const CSSAnimation& aOther) const;
void SetAnimationIndex(uint64_t aIndex) {
if (IsRelevant() && mAnimationIndex != aIndex) {
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 {
CSSAnimationProperties GetOverriddenProperties() const {
return mOverriddenProperties;
void AddOverriddenProperties(CSSAnimationProperties aProperties) {
mOverriddenProperties |= aProperties;
virtual ~CSSAnimation() {
"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->NormalizedTiming().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 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;
// Properties that would normally be defined by the cascade but which have
// since been explicitly set via the Web Animations API.
CSSAnimationProperties mOverriddenProperties = CSSAnimationProperties::None;
// A subclass of KeyframeEffect that reports when specific properties have been
// overridden via the Web Animations API.
class CSSAnimationKeyframeEffect : public KeyframeEffect {
CSSAnimationKeyframeEffect(Document* aDocument,
OwningAnimationTarget&& aTarget,
TimingParams&& aTiming,
const KeyframeEffectParams& aOptions)
: KeyframeEffect(aDocument, std::move(aTarget), std::move(aTiming),
aOptions) {}
void GetTiming(EffectTiming& aRetVal) const override;
void GetComputedTimingAsDict(ComputedEffectTiming& aRetVal) const override;
void UpdateTiming(const OptionalEffectTiming& aTiming,
ErrorResult& aRv) override;
void SetKeyframes(JSContext* aContext, JS::Handle<JSObject*> aKeyframes,
ErrorResult& aRv) override;
void SetComposite(const CompositeOperation& aComposite) override;
CSSAnimation* GetOwningCSSAnimation() {
return mAnimation ? mAnimation->AsCSSAnimation() : nullptr;
const CSSAnimation* GetOwningCSSAnimation() const {
return mAnimation ? mAnimation->AsCSSAnimation() : nullptr;
// Flushes styles if our owning animation is a CSSAnimation
void MaybeFlushUnanimatedStyle() const;
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_CSSAnimation_h