gecko-dev/layout/style/nsTransitionManager.cpp

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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 start and animate CSS transitions. */
#include "nsTransitionManager.h"
#include "nsAnimationManager.h"
#include "mozilla/dom/CSSTransitionBinding.h"
#include "nsIContent.h"
#include "mozilla/ComputedStyle.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/TimeStamp.h"
#include "nsRefreshDriver.h"
#include "nsCSSPropertyIDSet.h"
#include "mozilla/AnimationEventDispatcher.h"
#include "mozilla/EffectCompositor.h"
#include "mozilla/EffectSet.h"
#include "mozilla/EventDispatcher.h"
#include "mozilla/ServoBindings.h"
#include "mozilla/StyleAnimationValue.h"
#include "mozilla/dom/DocumentTimeline.h"
#include "mozilla/dom/Element.h"
#include "nsIFrame.h"
#include "Layers.h"
#include "FrameLayerBuilder.h"
#include "nsCSSProps.h"
#include "nsCSSPseudoElements.h"
#include "nsDisplayList.h"
#include "nsRFPService.h"
#include "nsStyleChangeList.h"
#include "mozilla/RestyleManager.h"
#include "nsDOMMutationObserver.h"
using mozilla::TimeStamp;
using mozilla::TimeDuration;
using mozilla::dom::Animation;
using mozilla::dom::AnimationPlayState;
using mozilla::dom::CSSTransition;
using mozilla::dom::Nullable;
using namespace mozilla;
using namespace mozilla::css;
double
ElementPropertyTransition::CurrentValuePortion() const
{
MOZ_ASSERT(!GetLocalTime().IsNull(),
"Getting the value portion of an animation that's not being "
"sampled");
// Transitions use a fill mode of 'backwards' so GetComputedTiming will
// never return a null time progress due to being *before* the animation
// interval. However, it might be possible that we're behind on flushing
// causing us to get called *after* the animation interval. So, just in
// case, we override the fill mode to 'both' to ensure the progress
// is never null.
TimingParams timingToUse = SpecifiedTiming();
timingToUse.SetFill(dom::FillMode::Both);
ComputedTiming computedTiming = GetComputedTiming(&timingToUse);
MOZ_ASSERT(!computedTiming.mProgress.IsNull(),
"Got a null progress for a fill mode of 'both'");
MOZ_ASSERT(mKeyframes.Length() == 2,
"Should have two animation keyframes for a transition");
return ComputedTimingFunction::GetPortion(mKeyframes[0].mTimingFunction,
computedTiming.mProgress.Value(),
computedTiming.mBeforeFlag);
}
void
ElementPropertyTransition::UpdateStartValueFromReplacedTransition()
{
if (!mReplacedTransition) {
return;
}
MOZ_ASSERT(nsCSSProps::PropHasFlags(TransitionProperty(),
CSSPropFlags::CanAnimateOnCompositor),
"The transition property should be able to be run on the "
"compositor");
MOZ_ASSERT(mTarget && mTarget->mElement->OwnerDoc(),
"We should have a valid document at this moment");
dom::DocumentTimeline* timeline = mTarget->mElement->OwnerDoc()->Timeline();
ComputedTiming computedTiming = GetComputedTimingAt(
dom::CSSTransition::GetCurrentTimeAt(*timeline,
TimeStamp::Now(),
mReplacedTransition->mStartTime,
mReplacedTransition->mPlaybackRate),
mReplacedTransition->mTiming,
mReplacedTransition->mPlaybackRate);
if (!computedTiming.mProgress.IsNull()) {
double valuePosition =
ComputedTimingFunction::GetPortion(mReplacedTransition->mTimingFunction,
computedTiming.mProgress.Value(),
computedTiming.mBeforeFlag);
MOZ_ASSERT(mProperties.Length() == 1 &&
mProperties[0].mSegments.Length() == 1,
"The transition should have one property and one segment");
MOZ_ASSERT(mKeyframes.Length() == 2,
"Transitions should have exactly two animation keyframes");
MOZ_ASSERT(mKeyframes[0].mPropertyValues.Length() == 1,
"Transitions should have exactly one property in their first "
"frame");
const AnimationValue& replacedFrom = mReplacedTransition->mFromValue;
const AnimationValue& replacedTo = mReplacedTransition->mToValue;
AnimationValue startValue;
startValue.mServo =
Servo_AnimationValues_Interpolate(replacedFrom.mServo,
replacedTo.mServo,
valuePosition).Consume();
if (startValue.mServo) {
mKeyframes[0].mPropertyValues[0].mServoDeclarationBlock =
Servo_AnimationValue_Uncompute(startValue.mServo).Consume();
mProperties[0].mSegments[0].mFromValue = std::move(startValue);
}
}
mReplacedTransition.reset();
}
////////////////////////// CSSTransition ////////////////////////////
JSObject*
CSSTransition::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
return dom::CSSTransition_Binding::Wrap(aCx, this, aGivenProto);
}
void
CSSTransition::GetTransitionProperty(nsString& aRetVal) const
{
MOZ_ASSERT(eCSSProperty_UNKNOWN != mTransitionProperty,
"Transition Property should be initialized");
aRetVal =
NS_ConvertUTF8toUTF16(nsCSSProps::GetStringValue(mTransitionProperty));
}
AnimationPlayState
CSSTransition::PlayStateFromJS() const
{
FlushUnanimatedStyle();
return Animation::PlayStateFromJS();
}
bool
CSSTransition::PendingFromJS() const
{
// Transitions don't become pending again after they start running but, if
// while the transition is still pending, style is updated in such a way
// that the transition will be canceled, we need to report false here.
// Hence we need to flush, but only when we're pending.
if (Pending()) {
FlushUnanimatedStyle();
}
return Animation::PendingFromJS();
}
void
CSSTransition::PlayFromJS(ErrorResult& aRv)
{
FlushUnanimatedStyle();
Animation::PlayFromJS(aRv);
}
void
CSSTransition::UpdateTiming(SeekFlag aSeekFlag, SyncNotifyFlag aSyncNotifyFlag)
{
if (mNeedsNewAnimationIndexWhenRun &&
PlayState() != AnimationPlayState::Idle) {
mAnimationIndex = sNextAnimationIndex++;
mNeedsNewAnimationIndexWhenRun = false;
}
Animation::UpdateTiming(aSeekFlag, aSyncNotifyFlag);
}
void
CSSTransition::QueueEvents(const StickyTimeDuration& aActiveTime)
{
if (!mOwningElement.IsSet()) {
return;
}
nsPresContext* presContext = mOwningElement.GetPresContext();
if (!presContext) {
return;
}
static constexpr StickyTimeDuration zeroDuration = StickyTimeDuration();
TransitionPhase currentPhase;
StickyTimeDuration intervalStartTime;
StickyTimeDuration intervalEndTime;
if (!mEffect) {
currentPhase = GetAnimationPhaseWithoutEffect<TransitionPhase>(*this);
} else {
ComputedTiming computedTiming = mEffect->GetComputedTiming();
currentPhase = static_cast<TransitionPhase>(computedTiming.mPhase);
intervalStartTime = IntervalStartTime(computedTiming.mActiveDuration);
intervalEndTime = IntervalEndTime(computedTiming.mActiveDuration);
}
if (mPendingState != PendingState::NotPending &&
(mPreviousTransitionPhase == TransitionPhase::Idle ||
mPreviousTransitionPhase == TransitionPhase::Pending)) {
currentPhase = TransitionPhase::Pending;
}
if (currentPhase == mPreviousTransitionPhase) {
return;
}
// TimeStamps to use for ordering the events when they are dispatched. We
// use a TimeStamp so we can compare events produced by different elements,
// perhaps even with different timelines.
// The zero timestamp is for transitionrun events where we ignore the delay
// for the purpose of ordering events.
TimeStamp zeroTimeStamp = AnimationTimeToTimeStamp(zeroDuration);
TimeStamp startTimeStamp = ElapsedTimeToTimeStamp(intervalStartTime);
TimeStamp endTimeStamp = ElapsedTimeToTimeStamp(intervalEndTime);
AutoTArray<AnimationEventInfo, 3> events;
auto appendTransitionEvent = [&](EventMessage aMessage,
const StickyTimeDuration& aElapsedTime,
const TimeStamp& aScheduledEventTimeStamp) {
double elapsedTime = aElapsedTime.ToSeconds();
if (aMessage == eTransitionCancel) {
// 0 is an inappropriate value for this callsite. What we need to do is
// use a single random value for all increasing times reportable.
// That is to say, whenever elapsedTime goes negative (because an
// animation restarts, something rewinds the animation, or otherwise)
// a new random value for the mix-in must be generated.
elapsedTime = nsRFPService::ReduceTimePrecisionAsSecs(elapsedTime, 0, TimerPrecisionType::RFPOnly);
}
events.AppendElement(AnimationEventInfo(TransitionProperty(),
mOwningElement.Target(),
aMessage,
elapsedTime,
aScheduledEventTimeStamp,
this));
};
// Handle cancel events first
if ((mPreviousTransitionPhase != TransitionPhase::Idle &&
mPreviousTransitionPhase != TransitionPhase::After) &&
currentPhase == TransitionPhase::Idle) {
appendTransitionEvent(eTransitionCancel,
aActiveTime,
GetTimelineCurrentTimeAsTimeStamp());
}
// All other events
switch (mPreviousTransitionPhase) {
case TransitionPhase::Idle:
if (currentPhase == TransitionPhase::Pending ||
currentPhase == TransitionPhase::Before) {
appendTransitionEvent(eTransitionRun, intervalStartTime, zeroTimeStamp);
} else if (currentPhase == TransitionPhase::Active) {
appendTransitionEvent(eTransitionRun, intervalStartTime, zeroTimeStamp);
appendTransitionEvent(eTransitionStart,
intervalStartTime,
startTimeStamp);
} else if (currentPhase == TransitionPhase::After) {
appendTransitionEvent(eTransitionRun, intervalStartTime, zeroTimeStamp);
appendTransitionEvent(eTransitionStart,
intervalStartTime,
startTimeStamp);
appendTransitionEvent(eTransitionEnd, intervalEndTime, endTimeStamp);
}
break;
case TransitionPhase::Pending:
case TransitionPhase::Before:
if (currentPhase == TransitionPhase::Active) {
appendTransitionEvent(eTransitionStart,
intervalStartTime,
startTimeStamp);
} else if (currentPhase == TransitionPhase::After) {
appendTransitionEvent(eTransitionStart,
intervalStartTime,
startTimeStamp);
appendTransitionEvent(eTransitionEnd, intervalEndTime, endTimeStamp);
}
break;
case TransitionPhase::Active:
if (currentPhase == TransitionPhase::After) {
appendTransitionEvent(eTransitionEnd, intervalEndTime, endTimeStamp);
} else if (currentPhase == TransitionPhase::Before) {
appendTransitionEvent(eTransitionEnd,
intervalStartTime,
startTimeStamp);
}
break;
case TransitionPhase::After:
if (currentPhase == TransitionPhase::Active) {
appendTransitionEvent(eTransitionStart,
intervalEndTime,
startTimeStamp);
} else if (currentPhase == TransitionPhase::Before) {
appendTransitionEvent(eTransitionStart,
intervalEndTime,
startTimeStamp);
appendTransitionEvent(eTransitionEnd,
intervalStartTime,
endTimeStamp);
}
break;
}
mPreviousTransitionPhase = currentPhase;
if (!events.IsEmpty()) {
presContext->AnimationEventDispatcher()->QueueEvents(std::move(events));
}
}
void
CSSTransition::Tick()
{
Animation::Tick();
QueueEvents();
}
nsCSSPropertyID
CSSTransition::TransitionProperty() const
{
MOZ_ASSERT(eCSSProperty_UNKNOWN != mTransitionProperty,
"Transition property should be initialized");
return mTransitionProperty;
}
AnimationValue
CSSTransition::ToValue() const
{
MOZ_ASSERT(!mTransitionToValue.IsNull(),
"Transition ToValue should be initialized");
return mTransitionToValue;
}
bool
CSSTransition::HasLowerCompositeOrderThan(const CSSTransition& aOther) const
{
MOZ_ASSERT(IsTiedToMarkup() && aOther.IsTiedToMarkup(),
"Should only be called for CSS transitions that are sorted "
"as CSS transitions (i.e. tied to CSS markup)");
// 0. Object-equality case
if (&aOther == this) {
return false;
}
// 1. Sort by document order
if (!mOwningElement.Equals(aOther.mOwningElement)) {
return mOwningElement.LessThan(
const_cast<CSSTransition*>(this)->CachedChildIndexRef(),
aOther.mOwningElement,
const_cast<CSSTransition*>(&aOther)->CachedChildIndexRef());
}
// 2. (Same element and pseudo): Sort by transition generation
if (mAnimationIndex != aOther.mAnimationIndex) {
return mAnimationIndex < aOther.mAnimationIndex;
}
// 3. (Same transition generation): Sort by transition property
return nsCSSProps::GetStringValue(TransitionProperty()) <
nsCSSProps::GetStringValue(aOther.TransitionProperty());
}
/* static */ Nullable<TimeDuration>
CSSTransition::GetCurrentTimeAt(const dom::DocumentTimeline& aTimeline,
const TimeStamp& aBaseTime,
const TimeDuration& aStartTime,
double aPlaybackRate)
{
Nullable<TimeDuration> result;
Nullable<TimeDuration> timelineTime = aTimeline.ToTimelineTime(aBaseTime);
if (!timelineTime.IsNull()) {
result.SetValue((timelineTime.Value() - aStartTime)
.MultDouble(aPlaybackRate));
}
return result;
}
void
CSSTransition::SetEffectFromStyle(dom::AnimationEffect* aEffect)
{
Animation::SetEffectNoUpdate(aEffect);
// Initialize transition property.
ElementPropertyTransition* pt = aEffect ? aEffect->AsTransition() : nullptr;
if (eCSSProperty_UNKNOWN == mTransitionProperty && pt) {
mTransitionProperty = pt->TransitionProperty();
mTransitionToValue = pt->ToValue();
}
}
////////////////////////// nsTransitionManager ////////////////////////////
static inline bool
ExtractNonDiscreteComputedValue(nsCSSPropertyID aProperty,
const ComputedStyle& aComputedStyle,
AnimationValue& aAnimationValue)
{
if (Servo_Property_IsDiscreteAnimatable(aProperty) &&
aProperty != eCSSProperty_visibility) {
return false;
}
aAnimationValue.mServo =
Servo_ComputedValues_ExtractAnimationValue(&aComputedStyle,
aProperty).Consume();
return !!aAnimationValue.mServo;
}
bool
nsTransitionManager::UpdateTransitions(
dom::Element *aElement,
CSSPseudoElementType aPseudoType,
const ComputedStyle& aOldStyle,
const ComputedStyle& aNewStyle)
{
if (!mPresContext->IsDynamic()) {
// For print or print preview, ignore transitions.
return false;
}
CSSTransitionCollection* collection =
CSSTransitionCollection::GetAnimationCollection(aElement, aPseudoType);
const nsStyleDisplay* disp =
aNewStyle.ComputedData()->GetStyleDisplay();
return DoUpdateTransitions(*disp,
aElement, aPseudoType,
collection,
aOldStyle, aNewStyle);
}
bool
nsTransitionManager::DoUpdateTransitions(
const nsStyleDisplay& aDisp,
dom::Element* aElement,
CSSPseudoElementType aPseudoType,
CSSTransitionCollection*& aElementTransitions,
const ComputedStyle& aOldStyle,
const ComputedStyle& aNewStyle)
{
MOZ_ASSERT(!aElementTransitions ||
aElementTransitions->mElement == aElement, "Element mismatch");
// Per http://lists.w3.org/Archives/Public/www-style/2009Aug/0109.html
// I'll consider only the transitions from the number of items in
// 'transition-property' on down, and later ones will override earlier
// ones (tracked using |propertiesChecked|).
bool startedAny = false;
nsCSSPropertyIDSet propertiesChecked;
for (uint32_t i = aDisp.mTransitionPropertyCount; i--; ) {
// We're not going to look at any further transitions, so we can just avoid
// looking at this if we know it will not start any transitions.
if (i == 0 && aDisp.GetTransitionCombinedDuration(i) <= 0.0f) {
continue;
}
nsCSSPropertyID property = aDisp.GetTransitionProperty(i);
if (property == eCSSPropertyExtra_no_properties ||
property == eCSSPropertyExtra_variable ||
property == eCSSProperty_UNKNOWN) {
// Nothing to do.
continue;
}
// We might have something to transition. See if any of the
// properties in question changed and are animatable.
// FIXME: Would be good to find a way to share code between this
// interpretation of transition-property and the one below.
// FIXME(emilio): This should probably just use the "all" shorthand id, and
// we should probably remove eCSSPropertyExtra_all_properties.
if (property == eCSSPropertyExtra_all_properties) {
for (nsCSSPropertyID p = nsCSSPropertyID(0);
p < eCSSProperty_COUNT_no_shorthands;
p = nsCSSPropertyID(p + 1)) {
if (!nsCSSProps::IsEnabled(p, CSSEnabledState::eForAllContent)) {
continue;
}
startedAny |=
ConsiderInitiatingTransition(p, aDisp, i, aElement, aPseudoType,
aElementTransitions,
aOldStyle, aNewStyle,
propertiesChecked);
}
} else if (nsCSSProps::IsShorthand(property)) {
CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(subprop, property,
CSSEnabledState::eForAllContent)
{
startedAny |=
ConsiderInitiatingTransition(*subprop, aDisp, i, aElement, aPseudoType,
aElementTransitions,
aOldStyle, aNewStyle,
propertiesChecked);
}
} else {
startedAny |=
ConsiderInitiatingTransition(property, aDisp, i, aElement, aPseudoType,
aElementTransitions,
aOldStyle, aNewStyle,
propertiesChecked);
}
}
// Stop any transitions for properties that are no longer in
// 'transition-property', including finished transitions.
// Also stop any transitions (and remove any finished transitions)
// for properties that just changed (and are still in the set of
// properties to transition), but for which we didn't just start the
// transition. This can happen delay and duration are both zero, or
// because the new value is not interpolable.
// Note that we also do the latter set of work in
// nsTransitionManager::PruneCompletedTransitions.
if (aElementTransitions) {
bool checkProperties =
aDisp.GetTransitionProperty(0) != eCSSPropertyExtra_all_properties;
nsCSSPropertyIDSet allTransitionProperties;
if (checkProperties) {
for (uint32_t i = aDisp.mTransitionPropertyCount; i-- != 0; ) {
// FIXME: Would be good to find a way to share code between this
// interpretation of transition-property and the one above.
nsCSSPropertyID property = aDisp.GetTransitionProperty(i);
if (property == eCSSPropertyExtra_no_properties ||
property == eCSSPropertyExtra_variable ||
property == eCSSProperty_UNKNOWN) {
// Nothing to do, but need to exclude this from cases below.
} else if (property == eCSSPropertyExtra_all_properties) {
for (nsCSSPropertyID p = nsCSSPropertyID(0);
p < eCSSProperty_COUNT_no_shorthands;
p = nsCSSPropertyID(p + 1)) {
allTransitionProperties.AddProperty(nsCSSProps::Physicalize(p, aNewStyle));
}
} else if (nsCSSProps::IsShorthand(property)) {
CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(
subprop, property, CSSEnabledState::eForAllContent) {
auto p = nsCSSProps::Physicalize(*subprop, aNewStyle);
allTransitionProperties.AddProperty(p);
}
} else {
allTransitionProperties.AddProperty(
nsCSSProps::Physicalize(property, aNewStyle));
}
}
}
OwningCSSTransitionPtrArray& animations = aElementTransitions->mAnimations;
size_t i = animations.Length();
MOZ_ASSERT(i != 0, "empty transitions list?");
AnimationValue currentValue;
do {
--i;
CSSTransition* anim = animations[i];
// properties no longer in 'transition-property'
if ((checkProperties &&
!allTransitionProperties.HasProperty(anim->TransitionProperty())) ||
// properties whose computed values changed but for which we
// did not start a new transition (because delay and
// duration are both zero, or because the new value is not
// interpolable); a new transition would have anim->ToValue()
// matching currentValue
!ExtractNonDiscreteComputedValue(anim->TransitionProperty(),
aNewStyle, currentValue) ||
currentValue != anim->ToValue()) {
// stop the transition
if (anim->HasCurrentEffect()) {
EffectSet* effectSet =
EffectSet::GetEffectSet(aElement, aPseudoType);
if (effectSet) {
effectSet->UpdateAnimationGeneration(mPresContext);
}
}
anim->CancelFromStyle();
animations.RemoveElementAt(i);
}
} while (i != 0);
if (animations.IsEmpty()) {
aElementTransitions->Destroy();
aElementTransitions = nullptr;
}
}
return startedAny;
}
static Keyframe&
AppendKeyframe(double aOffset,
nsCSSPropertyID aProperty,
AnimationValue&& aValue,
nsTArray<Keyframe>& aKeyframes)
{
Keyframe& frame = *aKeyframes.AppendElement();
frame.mOffset.emplace(aOffset);
if (aValue.mServo) {
RefPtr<RawServoDeclarationBlock> decl =
Servo_AnimationValue_Uncompute(aValue.mServo).Consume();
frame.mPropertyValues.AppendElement(
PropertyValuePair(aProperty, std::move(decl)));
} else {
MOZ_CRASH("old style system disabled");
}
return frame;
}
static nsTArray<Keyframe>
GetTransitionKeyframes(nsCSSPropertyID aProperty,
AnimationValue&& aStartValue,
AnimationValue&& aEndValue,
const nsTimingFunction& aTimingFunction)
{
nsTArray<Keyframe> keyframes(2);
Keyframe& fromFrame = AppendKeyframe(0.0, aProperty, std::move(aStartValue),
keyframes);
if (!aTimingFunction.IsLinear()) {
fromFrame.mTimingFunction.emplace();
fromFrame.mTimingFunction->Init(aTimingFunction);
}
AppendKeyframe(1.0, aProperty, std::move(aEndValue), keyframes);
return keyframes;
}
static bool
IsTransitionable(nsCSSPropertyID aProperty)
{
return Servo_Property_IsTransitionable(aProperty);
}
bool
nsTransitionManager::ConsiderInitiatingTransition(
nsCSSPropertyID aProperty,
const nsStyleDisplay& aStyleDisplay,
uint32_t transitionIdx,
dom::Element* aElement,
CSSPseudoElementType aPseudoType,
CSSTransitionCollection*& aElementTransitions,
const ComputedStyle& aOldStyle,
const ComputedStyle& aNewStyle,
nsCSSPropertyIDSet& aPropertiesChecked)
{
// IsShorthand itself will assert if aProperty is not a property.
MOZ_ASSERT(!nsCSSProps::IsShorthand(aProperty), "property out of range");
NS_ASSERTION(!aElementTransitions ||
aElementTransitions->mElement == aElement, "Element mismatch");
aProperty = nsCSSProps::Physicalize(aProperty, aNewStyle);
// A later item in transition-property already specified a transition for
// this property, so we ignore this one.
//
// See http://lists.w3.org/Archives/Public/www-style/2009Aug/0109.html .
if (aPropertiesChecked.HasProperty(aProperty)) {
return false;
}
aPropertiesChecked.AddProperty(aProperty);
if (!IsTransitionable(aProperty)) {
return false;
}
float delay = aStyleDisplay.GetTransitionDelay(transitionIdx);
// The spec says a negative duration is treated as zero.
float duration =
std::max(aStyleDisplay.GetTransitionDuration(transitionIdx), 0.0f);
// If the combined duration of this transition is 0 or less don't start a
// transition.
if (delay + duration <= 0.0f) {
return false;
}
dom::DocumentTimeline* timeline = aElement->OwnerDoc()->Timeline();
AnimationValue startValue, endValue;
bool haveValues =
ExtractNonDiscreteComputedValue(aProperty, aOldStyle, startValue) &&
ExtractNonDiscreteComputedValue(aProperty, aNewStyle, endValue);
bool haveChange = startValue != endValue;
bool shouldAnimate =
haveValues &&
haveChange &&
startValue.IsInterpolableWith(aProperty, endValue);
bool haveCurrentTransition = false;
size_t currentIndex = nsTArray<ElementPropertyTransition>::NoIndex;
const ElementPropertyTransition *oldPT = nullptr;
if (aElementTransitions) {
OwningCSSTransitionPtrArray& animations = aElementTransitions->mAnimations;
for (size_t i = 0, i_end = animations.Length(); i < i_end; ++i) {
if (animations[i]->TransitionProperty() == aProperty) {
haveCurrentTransition = true;
currentIndex = i;
oldPT = animations[i]->GetEffect()
? animations[i]->GetEffect()->AsTransition()
: nullptr;
break;
}
}
}
// If we got a style change that changed the value to the endpoint
// of the currently running transition, we don't want to interrupt
// its timing function.
// This needs to be before the !shouldAnimate && haveCurrentTransition
// case below because we might be close enough to the end of the
// transition that the current value rounds to the final value. In
// this case, we'll end up with shouldAnimate as false (because
// there's no value change), but we need to return early here rather
// than cancel the running transition because shouldAnimate is false!
//
// Likewise, if we got a style change that changed the value to the
// endpoint of our finished transition, we also don't want to start
// a new transition for the reasons described in
// https://lists.w3.org/Archives/Public/www-style/2015Jan/0444.html .
if (haveCurrentTransition && haveValues &&
aElementTransitions->mAnimations[currentIndex]->ToValue() == endValue) {
// GetAnimationRule already called RestyleForAnimation.
return false;
}
if (!shouldAnimate) {
if (haveCurrentTransition) {
// We're in the middle of a transition, and just got a non-transition
// style change to something that we can't animate. This might happen
// because we got a non-transition style change changing to the current
// in-progress value (which is particularly easy to cause when we're
// currently in the 'transition-delay'). It also might happen because we
// just got a style change to a value that can't be interpolated.
OwningCSSTransitionPtrArray& animations =
aElementTransitions->mAnimations;
animations[currentIndex]->CancelFromStyle();
oldPT = nullptr; // Clear pointer so it doesn't dangle
animations.RemoveElementAt(currentIndex);
EffectSet* effectSet = EffectSet::GetEffectSet(aElement, aPseudoType);
if (effectSet) {
effectSet->UpdateAnimationGeneration(mPresContext);
}
if (animations.IsEmpty()) {
aElementTransitions->Destroy();
// |aElementTransitions| is now a dangling pointer!
aElementTransitions = nullptr;
}
// GetAnimationRule already called RestyleForAnimation.
}
return false;
}
const nsTimingFunction &tf =
aStyleDisplay.GetTransitionTimingFunction(transitionIdx);
AnimationValue startForReversingTest = startValue;
double reversePortion = 1.0;
// If the new transition reverses an existing one, we'll need to
// handle the timing differently.
// FIXME: Move mStartForReversingTest, mReversePortion to CSSTransition,
// and set the timing function on transitions as an effect-level
// easing (rather than keyframe-level easing). (Bug 1292001)
if (haveCurrentTransition &&
aElementTransitions->mAnimations[currentIndex]->HasCurrentEffect() &&
oldPT &&
oldPT->mStartForReversingTest == endValue) {
// Compute the appropriate negative transition-delay such that right
// now we'd end up at the current position.
double valuePortion =
oldPT->CurrentValuePortion() * oldPT->mReversePortion +
(1.0 - oldPT->mReversePortion);
// A timing function with negative y1 (or y2!) might make
// valuePortion negative. In this case, we still want to apply our
// reversing logic based on relative distances, not make duration
// negative.
if (valuePortion < 0.0) {
valuePortion = -valuePortion;
}
// A timing function with y2 (or y1!) greater than one might
// advance past its terminal value. It's probably a good idea to
// clamp valuePortion to be at most one to preserve the invariant
// that a transition will complete within at most its specified
// time.
if (valuePortion > 1.0) {
valuePortion = 1.0;
}
// Negative delays are essentially part of the transition
// function, so reduce them along with the duration, but don't
// reduce positive delays.
if (delay < 0.0f) {
delay *= valuePortion;
}
duration *= valuePortion;
startForReversingTest = oldPT->ToValue();
reversePortion = valuePortion;
}
TimingParams timing =
TimingParamsFromCSSParams(duration, delay,
1.0 /* iteration count */,
dom::PlaybackDirection::Normal,
dom::FillMode::Backwards);
// aElement is non-null here, so we emplace it directly.
Maybe<OwningAnimationTarget> target;
target.emplace(aElement, aPseudoType);
KeyframeEffectParams effectOptions;
RefPtr<ElementPropertyTransition> pt =
new ElementPropertyTransition(aElement->OwnerDoc(), target, std::move(timing),
startForReversingTest, reversePortion,
effectOptions);
pt->SetKeyframes(GetTransitionKeyframes(aProperty,
std::move(startValue), std::move(endValue), tf),
&aNewStyle);
RefPtr<CSSTransition> animation =
new CSSTransition(mPresContext->Document()->GetScopeObject());
animation->SetOwningElement(OwningElementRef(*aElement, aPseudoType));
animation->SetTimelineNoUpdate(timeline);
animation->SetCreationSequence(
mPresContext->RestyleManager()->GetAnimationGeneration());
animation->SetEffectFromStyle(pt);
animation->PlayFromStyle();
if (!aElementTransitions) {
bool createdCollection = false;
aElementTransitions =
CSSTransitionCollection::GetOrCreateAnimationCollection(
aElement, aPseudoType, &createdCollection);
if (!aElementTransitions) {
MOZ_ASSERT(!createdCollection, "outparam should agree with return value");
NS_WARNING("allocating collection failed");
return false;
}
if (createdCollection) {
AddElementCollection(aElementTransitions);
}
}
OwningCSSTransitionPtrArray& animations = aElementTransitions->mAnimations;
#ifdef DEBUG
for (size_t i = 0, i_end = animations.Length(); i < i_end; ++i) {
MOZ_ASSERT(
i == currentIndex || animations[i]->TransitionProperty() != aProperty,
"duplicate transitions for property");
}
#endif
if (haveCurrentTransition) {
// If this new transition is replacing an existing transition that is running
// on the compositor, we store select parameters from the replaced transition
// so that later, once all scripts have run, we can update the start value
// of the transition using TimeStamp::Now(). This allows us to avoid a
// large jump when starting a new transition when the main thread lags behind
// the compositor.
if (oldPT &&
oldPT->IsCurrent() &&
oldPT->IsRunningOnCompositor() &&
!oldPT->GetAnimation()->GetStartTime().IsNull() &&
timeline == oldPT->GetAnimation()->GetTimeline()) {
const AnimationPropertySegment& segment =
oldPT->Properties()[0].mSegments[0];
pt->mReplacedTransition.emplace(
ElementPropertyTransition::ReplacedTransitionProperties({
oldPT->GetAnimation()->GetStartTime().Value(),
oldPT->GetAnimation()->PlaybackRate(),
oldPT->SpecifiedTiming(),
segment.mTimingFunction,
segment.mFromValue,
segment.mToValue
})
);
}
animations[currentIndex]->CancelFromStyle();
oldPT = nullptr; // Clear pointer so it doesn't dangle
animations[currentIndex] = animation;
} else {
if (!animations.AppendElement(animation)) {
NS_WARNING("out of memory");
return false;
}
}
EffectSet* effectSet = EffectSet::GetEffectSet(aElement, aPseudoType);
if (effectSet) {
effectSet->UpdateAnimationGeneration(mPresContext);
}
return true;
}