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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 "mozilla/dom/Document.h"
#include "nsAnimationManager.h"
#include "nsIContent.h"
#include "mozilla/ComputedStyle.h"
#include "mozilla/MemoryReporting.h"
#include "nsCSSPropertyIDSet.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 "nsCSSProps.h"
#include "nsCSSPseudoElements.h"
#include "nsDisplayList.h"
#include "nsRFPService.h"
#include "nsStyleChangeList.h"
#include "mozilla/RestyleManager.h"
using mozilla::dom::CSSTransition;
using mozilla::dom::DocumentTimeline;
using mozilla::dom::KeyframeEffect;
using namespace mozilla;
using namespace mozilla::css;
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,
PseudoStyleType aPseudoType,
const ComputedStyle& aOldStyle,
const ComputedStyle& aNewStyle) {
if (!mPresContext->IsDynamic()) {
// For print or print preview, ignore transitions.
return false;
}
if (aNewStyle.StyleDisplay()->mDisplay == StyleDisplay::None) {
StopAnimationsForElement(aElement, aPseudoType);
return false;
}
CSSTransitionCollection* collection =
CSSTransitionCollection::GetAnimationCollection(aElement, aPseudoType);
return DoUpdateTransitions(*aNewStyle.StyleUIReset(), aElement, aPseudoType,
collection, aOldStyle, aNewStyle);
}
bool nsTransitionManager::DoUpdateTransitions(
const nsStyleUIReset& aStyle, dom::Element* aElement,
PseudoStyleType aPseudoType, CSSTransitionCollection*& aElementTransitions,
const ComputedStyle& aOldStyle, const ComputedStyle& aNewStyle) {
MOZ_ASSERT(!aElementTransitions || aElementTransitions->mElement == aElement,
"Element mismatch");
// 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 = aStyle.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 && aStyle.GetTransitionCombinedDuration(i) <= 0.0f) {
continue;
}
nsCSSPropertyID property = aStyle.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::ForAllContent)) {
continue;
}
startedAny |= ConsiderInitiatingTransition(
p, aStyle, i, aElement, aPseudoType, aElementTransitions, aOldStyle,
aNewStyle, propertiesChecked);
}
} else if (nsCSSProps::IsShorthand(property)) {
CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(subprop, property,
CSSEnabledState::ForAllContent) {
startedAny |= ConsiderInitiatingTransition(
*subprop, aStyle, i, aElement, aPseudoType, aElementTransitions,
aOldStyle, aNewStyle, propertiesChecked);
}
} else {
startedAny |= ConsiderInitiatingTransition(
property, aStyle, 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 =
aStyle.GetTransitionProperty(0) != eCSSPropertyExtra_all_properties;
nsCSSPropertyIDSet allTransitionProperties;
if (checkProperties) {
for (uint32_t i = aStyle.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 = aStyle.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::ForAllContent) {
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(PostRestyleMode::IfNeeded);
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);
MOZ_ASSERT(aValue.mServo);
RefPtr<RawServoDeclarationBlock> decl =
Servo_AnimationValue_Uncompute(aValue.mServo).Consume();
frame.mPropertyValues.AppendElement(
PropertyValuePair(aProperty, std::move(decl)));
return frame;
}
static nsTArray<Keyframe> GetTransitionKeyframes(nsCSSPropertyID aProperty,
AnimationValue&& aStartValue,
AnimationValue&& aEndValue) {
nsTArray<Keyframe> keyframes(2);
AppendKeyframe(0.0, aProperty, std::move(aStartValue), keyframes);
AppendKeyframe(1.0, aProperty, std::move(aEndValue), keyframes);
return keyframes;
}
static bool IsTransitionable(nsCSSPropertyID aProperty) {
return Servo_Property_IsTransitionable(aProperty);
}
static Maybe<CSSTransition::ReplacedTransitionProperties>
GetReplacedTransitionProperties(const CSSTransition* aTransition,
const DocumentTimeline* aTimelineToMatch) {
Maybe<CSSTransition::ReplacedTransitionProperties> result;
// Transition needs to be currently running on the compositor to be
// replaceable.
if (!aTransition || !aTransition->HasCurrentEffect() ||
!aTransition->IsRunningOnCompositor() ||
aTransition->GetStartTime().IsNull()) {
return result;
}
// Transition needs to be running on the same timeline.
if (aTransition->GetTimeline() != aTimelineToMatch) {
return result;
}
// The transition needs to have a keyframe effect.
const KeyframeEffect* keyframeEffect =
aTransition->GetEffect() ? aTransition->GetEffect()->AsKeyframeEffect()
: nullptr;
if (!keyframeEffect) {
return result;
}
// The keyframe effect needs to be a simple transition of the original
// transition property (i.e. not replaced with something else).
if (keyframeEffect->Properties().Length() != 1 ||
keyframeEffect->Properties()[0].mSegments.Length() != 1 ||
keyframeEffect->Properties()[0].mProperty !=
aTransition->TransitionProperty()) {
return result;
}
const AnimationPropertySegment& segment =
keyframeEffect->Properties()[0].mSegments[0];
result.emplace(CSSTransition::ReplacedTransitionProperties(
{aTransition->GetStartTime().Value(), aTransition->PlaybackRate(),
keyframeEffect->SpecifiedTiming(), segment.mTimingFunction,
segment.mFromValue, segment.mToValue}));
return result;
}
bool nsTransitionManager::ConsiderInitiatingTransition(
nsCSSPropertyID aProperty, const nsStyleUIReset& aStyle,
uint32_t transitionIdx, dom::Element* aElement, PseudoStyleType 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.
//
if (aPropertiesChecked.HasProperty(aProperty)) {
return false;
}
aPropertiesChecked.AddProperty(aProperty);
if (!IsTransitionable(aProperty)) {
return false;
}
float delay = aStyle.GetTransitionDelay(transitionIdx);
// The spec says a negative duration is treated as zero.
float duration = std::max(aStyle.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<KeyframeEffect>::NoIndex;
const CSSTransition* oldTransition = 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;
oldTransition = animations[i];
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
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(PostRestyleMode::IfNeeded);
oldTransition = 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;
}
AnimationValue startForReversingTest = startValue;
double reversePortion = 1.0;
// If the new transition reverses an existing one, we'll need to
// handle the timing differently.
if (haveCurrentTransition &&
aElementTransitions->mAnimations[currentIndex]->HasCurrentEffect() &&
oldTransition && oldTransition->StartForReversingTest() == endValue) {
// Compute the appropriate negative transition-delay such that right
// now we'd end up at the current position.
double valuePortion =
oldTransition->CurrentValuePortion() * oldTransition->ReversePortion() +
(1.0 - oldTransition->ReversePortion());
// 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 = oldTransition->ToValue();
reversePortion = valuePortion;
}
TimingParams timing = TimingParamsFromCSSParams(
duration, delay, 1.0 /* iteration count */,
dom::PlaybackDirection::Normal, dom::FillMode::Backwards);
const StyleComputedTimingFunction& tf =
aStyle.GetTransitionTimingFunction(transitionIdx);
if (!tf.IsLinearKeyword()) {
timing.SetTimingFunction(Some(tf));
}
KeyframeEffectParams effectOptions;
RefPtr<KeyframeEffect> keyframeEffect = new KeyframeEffect(
aElement->OwnerDoc(), OwningAnimationTarget(aElement, aPseudoType),
std::move(timing), effectOptions);
keyframeEffect->SetKeyframes(
GetTransitionKeyframes(aProperty, std::move(startValue),
std::move(endValue)),
&aNewStyle);
if (NS_WARN_IF(MOZ_UNLIKELY(!keyframeEffect->IsValidTransition()))) {
return false;
}
RefPtr<CSSTransition> animation =
new CSSTransition(mPresContext->Document()->GetScopeObject());
animation->SetOwningElement(OwningElementRef(*aElement, aPseudoType));
animation->SetTimelineNoUpdate(timeline);
animation->SetCreationSequence(
mPresContext->RestyleManager()->GetAnimationGeneration());
animation->SetEffectFromStyle(keyframeEffect);
animation->SetReverseParameters(std::move(startForReversingTest),
reversePortion);
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.
auto replacedTransitionProperties =
GetReplacedTransitionProperties(oldTransition, timeline);
if (replacedTransitionProperties) {
animation->SetReplacedTransition(
std::move(replacedTransitionProperties.ref()));
}
animations[currentIndex]->CancelFromStyle(PostRestyleMode::IfNeeded);
oldTransition = nullptr; // Clear pointer so it doesn't dangle
animations[currentIndex] = animation;
} else {
// XXX(Bug 1631371) Check if this should use a fallible operation as it
// pretended earlier.
animations.AppendElement(animation);
}
EffectSet* effectSet = EffectSet::GetEffectSet(aElement, aPseudoType);
if (effectSet) {
effectSet->UpdateAnimationGeneration(mPresContext);
}
return true;
}