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Diffstat (limited to 'layout/style/nsTransitionManager.cpp')
| -rw-r--r-- | layout/style/nsTransitionManager.cpp | 497 |
1 files changed, 497 insertions, 0 deletions
diff --git a/layout/style/nsTransitionManager.cpp b/layout/style/nsTransitionManager.cpp new file mode 100644 index 0000000000..ad3809c37f --- /dev/null +++ b/layout/style/nsTransitionManager.cpp @@ -0,0 +1,497 @@ +/* -*- 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 "AnimatedPropertyID.h" +#include "AnimatedPropertyIDSet.h" +#include "mozilla/ComputedStyle.h" +#include "mozilla/MemoryReporting.h" +#include "nsCSSPropertyIDSet.h" +#include "mozilla/EffectSet.h" +#include "mozilla/ElementAnimationData.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 "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; + +bool nsTransitionManager::UpdateTransitions(dom::Element* aElement, + PseudoStyleType aPseudoType, + const ComputedStyle& aOldStyle, + const ComputedStyle& aNewStyle) { + if (mPresContext->Medium() == nsGkAtoms::print) { + // For print or print preview, ignore transitions. + return false; + } + + MOZ_ASSERT(mPresContext->IsDynamic()); + if (aNewStyle.StyleDisplay()->mDisplay == StyleDisplay::None) { + StopAnimationsForElement(aElement, aPseudoType); + return false; + } + + auto* collection = CSSTransitionCollection::Get(aElement, aPseudoType); + return DoUpdateTransitions(*aNewStyle.StyleUIReset(), aElement, aPseudoType, + collection, aOldStyle, aNewStyle); +} + +// This function expands the shorthands and "all" keyword specified in +// transition-property, and then execute |aHandler| on the expanded longhand. +// |aHandler| should be a lamda function which accepts nsCSSPropertyID. +template <typename T> +static void ExpandTransitionProperty(const StyleTransitionProperty& aProperty, + T aHandler) { + switch (aProperty.tag) { + case StyleTransitionProperty::Tag::Unsupported: + break; + case StyleTransitionProperty::Tag::Custom: { + AnimatedPropertyID property(aProperty.AsCustom().AsAtom()); + aHandler(property); + break; + } + case StyleTransitionProperty::Tag::NonCustom: { + nsCSSPropertyID id = nsCSSPropertyID(aProperty.AsNonCustom()._0); + if (nsCSSProps::IsShorthand(id)) { + CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(subprop, id, + CSSEnabledState::ForAllContent) { + AnimatedPropertyID property(*subprop); + aHandler(property); + } + } else { + AnimatedPropertyID property(id); + aHandler(property); + } + break; + } + } +} + +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"); + + // 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; + AnimatedPropertyIDSet propertiesChecked; + for (uint32_t i = aStyle.mTransitionPropertyCount; i--;) { + const float delay = aStyle.GetTransitionDelay(i).ToMilliseconds(); + + // The spec says a negative duration is treated as zero. + const float duration = + std::max(aStyle.GetTransitionDuration(i).ToMilliseconds(), 0.0f); + + // If the combined duration of this transition is 0 or less we won't start a + // transition, we can avoid even looking at transition-property if we're the + // last one. + if (i == 0 && delay + duration <= 0.0f) { + continue; + } + + ExpandTransitionProperty(aStyle.GetTransitionProperty(i), + [&](const AnimatedPropertyID& aProperty) { + // We might have something to transition. See if + // any of the properties in question changed and + // are animatable. + startedAny |= ConsiderInitiatingTransition( + aProperty, aStyle, i, delay, duration, + 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. + if (aElementTransitions) { + const bool checkProperties = !aStyle.GetTransitionProperty(0).IsAll(); + AnimatedPropertyIDSet allTransitionProperties; + if (checkProperties) { + for (uint32_t i = aStyle.mTransitionPropertyCount; i-- != 0;) { + ExpandTransitionProperty(aStyle.GetTransitionProperty(i), + [&](const AnimatedPropertyID& aProperty) { + allTransitionProperties.AddProperty( + aProperty.ToPhysical(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]; + const AnimatedPropertyID& property = anim->TransitionProperty(); + if ( + // Properties no longer in `transition-property`. + (checkProperties && !allTransitionProperties.HasProperty(property)) || + // 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. + !Servo_ComputedValues_TransitionValueMatches( + &aNewStyle, &property, anim->ToValue().mServo.get())) { + // Stop the transition. + DoCancelTransition(aElement, aPseudoType, aElementTransitions, i); + } + } while (i != 0); + } + + return startedAny; +} + +static Keyframe& AppendKeyframe(double aOffset, + const AnimatedPropertyID& aProperty, + AnimationValue&& aValue, + nsTArray<Keyframe>& aKeyframes) { + Keyframe& frame = *aKeyframes.AppendElement(); + frame.mOffset.emplace(aOffset); + MOZ_ASSERT(aValue.mServo); + RefPtr<StyleLockedDeclarationBlock> decl = + Servo_AnimationValue_Uncompute(aValue.mServo).Consume(); + frame.mPropertyValues.AppendElement( + PropertyValuePair(aProperty, std::move(decl))); + return frame; +} + +static nsTArray<Keyframe> GetTransitionKeyframes( + const AnimatedPropertyID& 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 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( + const AnimatedPropertyID& aProperty, const nsStyleUIReset& aStyle, + uint32_t aTransitionIndex, float aDelay, float aDuration, + dom::Element* aElement, PseudoStyleType aPseudoType, + CSSTransitionCollection*& aElementTransitions, + const ComputedStyle& aOldStyle, const ComputedStyle& aNewStyle, + AnimatedPropertyIDSet& aPropertiesChecked) { + // IsShorthand itself will assert if aProperty is not a property. + MOZ_ASSERT(aProperty.IsCustom() || !nsCSSProps::IsShorthand(aProperty.mID), + "property out of range"); + NS_ASSERTION( + !aElementTransitions || &aElementTransitions->mElement == aElement, + "Element mismatch"); + + AnimatedPropertyID property = aProperty.ToPhysical(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(property)) { + return false; + } + + aPropertiesChecked.AddProperty(property); + + if (aDuration + aDelay <= 0.0f) { + return false; + } + + size_t currentIndex = nsTArray<KeyframeEffect>::NoIndex; + const auto* oldTransition = [&]() -> const CSSTransition* { + if (!aElementTransitions) { + return nullptr; + } + const OwningCSSTransitionPtrArray& animations = + aElementTransitions->mAnimations; + for (size_t i = 0, i_end = animations.Length(); i < i_end; ++i) { + if (animations[i]->TransitionProperty() == property) { + currentIndex = i; + return animations[i]; + } + } + return nullptr; + }(); + + AnimationValue startValue, endValue; + const StyleShouldTransitionResult result = + Servo_ComputedValues_ShouldTransition( + &aOldStyle, &aNewStyle, &property, + oldTransition ? oldTransition->ToValue().mServo.get() : nullptr, + &startValue.mServo, &endValue.mServo); + + // 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 (result.old_transition_value_matches) { + // GetAnimationRule already called RestyleForAnimation. + return false; + } + + if (!result.should_animate) { + if (oldTransition) { + // 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. + DoCancelTransition(aElement, aPseudoType, aElementTransitions, + currentIndex); + } + 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 (oldTransition && oldTransition->HasCurrentEffect() && + 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 (aDelay < 0.0f && std::isfinite(aDelay)) { + aDelay *= valuePortion; + } + + if (std::isfinite(aDuration)) { + aDuration *= valuePortion; + } + + startForReversingTest = oldTransition->ToValue(); + reversePortion = valuePortion; + } + + TimingParams timing = TimingParamsFromCSSParams( + aDuration, aDelay, 1.0 /* iteration count */, + StyleAnimationDirection::Normal, StyleAnimationFillMode::Backwards); + + const StyleComputedTimingFunction& tf = + aStyle.GetTransitionTimingFunction(aTransitionIndex); + if (!tf.IsLinearKeyword()) { + timing.SetTimingFunction(Some(tf)); + } + + RefPtr<CSSTransition> transition = DoCreateTransition( + property, aElement, aPseudoType, aNewStyle, aElementTransitions, + std::move(timing), std::move(startValue), std::move(endValue), + std::move(startForReversingTest), reversePortion); + if (!transition) { + return false; + } + + OwningCSSTransitionPtrArray& transitions = aElementTransitions->mAnimations; +#ifdef DEBUG + for (size_t i = 0, i_end = transitions.Length(); i < i_end; ++i) { + MOZ_ASSERT( + i == currentIndex || transitions[i]->TransitionProperty() != property, + "duplicate transitions for property"); + } +#endif + if (oldTransition) { + // 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. + const dom::DocumentTimeline* timeline = aElement->OwnerDoc()->Timeline(); + auto replacedTransitionProperties = + GetReplacedTransitionProperties(oldTransition, timeline); + if (replacedTransitionProperties) { + transition->SetReplacedTransition( + std::move(replacedTransitionProperties.ref())); + } + + transitions[currentIndex]->CancelFromStyle(PostRestyleMode::IfNeeded); + oldTransition = nullptr; // Clear pointer so it doesn't dangle + transitions[currentIndex] = transition; + } else { + // XXX(Bug 1631371) Check if this should use a fallible operation as it + // pretended earlier. + transitions.AppendElement(transition); + } + + if (auto* effectSet = EffectSet::Get(aElement, aPseudoType)) { + effectSet->UpdateAnimationGeneration(mPresContext); + } + + return true; +} + +already_AddRefed<CSSTransition> nsTransitionManager::DoCreateTransition( + const AnimatedPropertyID& aProperty, dom::Element* aElement, + PseudoStyleType aPseudoType, const mozilla::ComputedStyle& aNewStyle, + CSSTransitionCollection*& aElementTransitions, TimingParams&& aTiming, + AnimationValue&& aStartValue, AnimationValue&& aEndValue, + AnimationValue&& aStartForReversingTest, double aReversePortion) { + dom::DocumentTimeline* timeline = aElement->OwnerDoc()->Timeline(); + KeyframeEffectParams effectOptions; + RefPtr<KeyframeEffect> keyframeEffect = new KeyframeEffect( + aElement->OwnerDoc(), OwningAnimationTarget(aElement, aPseudoType), + std::move(aTiming), effectOptions); + + keyframeEffect->SetKeyframes( + GetTransitionKeyframes(aProperty, std::move(aStartValue), + std::move(aEndValue)), + &aNewStyle, timeline); + + if (NS_WARN_IF(MOZ_UNLIKELY(!keyframeEffect->IsValidTransition()))) { + return nullptr; + } + + RefPtr<CSSTransition> animation = + new CSSTransition(mPresContext->Document()->GetScopeObject(), aProperty); + animation->SetOwningElement(OwningElementRef(*aElement, aPseudoType)); + animation->SetTimelineNoUpdate(timeline); + animation->SetCreationSequence( + mPresContext->RestyleManager()->GetAnimationGeneration()); + animation->SetEffectFromStyle(keyframeEffect); + animation->SetReverseParameters(std::move(aStartForReversingTest), + aReversePortion); + animation->PlayFromStyle(); + + if (!aElementTransitions) { + aElementTransitions = + &aElement->EnsureAnimationData().EnsureTransitionCollection( + *aElement, aPseudoType); + if (!aElementTransitions->isInList()) { + AddElementCollection(aElementTransitions); + } + } + return animation.forget(); +} + +void nsTransitionManager::DoCancelTransition( + dom::Element* aElement, PseudoStyleType aPseudoType, + CSSTransitionCollection*& aElementTransitions, size_t aIndex) { + MOZ_ASSERT(aElementTransitions); + OwningCSSTransitionPtrArray& transitions = aElementTransitions->mAnimations; + CSSTransition* transition = transitions[aIndex]; + + if (transition->HasCurrentEffect()) { + if (auto* effectSet = EffectSet::Get(aElement, aPseudoType)) { + effectSet->UpdateAnimationGeneration(mPresContext); + } + } + transition->CancelFromStyle(PostRestyleMode::IfNeeded); + transitions.RemoveElementAt(aIndex); + + if (transitions.IsEmpty()) { + aElementTransitions->Destroy(); + // |aElementTransitions| is now a dangling pointer! + aElementTransitions = nullptr; + } +} |