/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */ /* 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 "nsIContent.h" #include "nsStyleContext.h" #include "nsCSSProps.h" #include "mozilla/MemoryReporting.h" #include "mozilla/TimeStamp.h" #include "nsRefreshDriver.h" #include "nsRuleProcessorData.h" #include "nsRuleWalker.h" #include "nsCSSPropertySet.h" #include "mozilla/EventDispatcher.h" #include "mozilla/ContentEvents.h" #include "mozilla/StyleAnimationValue.h" #include "mozilla/dom/Element.h" #include "nsIFrame.h" #include "Layers.h" #include "FrameLayerBuilder.h" #include "nsDisplayList.h" #include "nsStyleChangeList.h" #include "nsStyleSet.h" #include "RestyleManager.h" using mozilla::TimeStamp; using mozilla::TimeDuration; using mozilla::dom::AnimationPlayer; using mozilla::dom::Animation; using namespace mozilla; using namespace mozilla::layers; using namespace mozilla::css; double ElementPropertyTransition::CurrentValuePortion() const { // It would be easy enough to handle finished transitions by using a time // fraction of 1 but currently we should not be called for finished // transitions. MOZ_ASSERT(!IsFinishedTransition(), "Getting the value portion of a finished transition"); 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 fraction 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 time fraction // is never null. AnimationTiming timingToUse = mTiming; timingToUse.mFillMode = NS_STYLE_ANIMATION_FILL_MODE_BOTH; ComputedTiming computedTiming = GetComputedTiming(&timingToUse); MOZ_ASSERT(computedTiming.mTimeFraction != ComputedTiming::kNullTimeFraction, "Got a null time fraction for a fill mode of 'both'"); MOZ_ASSERT(mProperties.Length() == 1, "Should have one animation property for a transition"); MOZ_ASSERT(mProperties[0].mSegments.Length() == 1, "Animation property should have one segment for a transition"); return mProperties[0].mSegments[0].mTimingFunction .GetValue(computedTiming.mTimeFraction); } /***************************************************************************** * nsTransitionManager * *****************************************************************************/ void nsTransitionManager::ElementCollectionRemoved() { // If we have no transitions or animations left, remove ourselves from // the refresh driver. if (PR_CLIST_IS_EMPTY(&mElementCollections)) { mPresContext->RefreshDriver()->RemoveRefreshObserver(this, Flush_Style); } } void nsTransitionManager::AddElementCollection( AnimationPlayerCollection* aCollection) { if (PR_CLIST_IS_EMPTY(&mElementCollections)) { // We need to observe the refresh driver. nsRefreshDriver *rd = mPresContext->RefreshDriver(); rd->AddRefreshObserver(this, Flush_Style); } PR_INSERT_BEFORE(aCollection, &mElementCollections); } already_AddRefed nsTransitionManager::StyleContextChanged(dom::Element *aElement, nsStyleContext *aOldStyleContext, nsStyleContext *aNewStyleContext) { NS_PRECONDITION(aOldStyleContext->GetPseudo() == aNewStyleContext->GetPseudo(), "pseudo type mismatch"); // If we were called from ReparentStyleContext, this assertion would // actually fire. If we need to be called from there, we can probably // just remove it; the condition probably isn't critical, although // it's worth thinking about some more. NS_PRECONDITION(aOldStyleContext->HasPseudoElementData() == aNewStyleContext->HasPseudoElementData(), "pseudo type mismatch"); if (mInAnimationOnlyStyleUpdate) { // If we're doing an animation-only style update, return, since the // purpose of an animation-only style update is to update only the // animation styles so that we don't consider style changes // resulting from changes in the animation time for starting a // transition. return nullptr; } if (!mPresContext->IsDynamic()) { // For print or print preview, ignore transitions. return nullptr; } // NOTE: Things in this function (and ConsiderStartingTransition) // should never call PeekStyleData because we don't preserve gotten // structs across reframes. // Return sooner (before the startedAny check below) for the most // common case: no transitions specified or running. const nsStyleDisplay *disp = aNewStyleContext->StyleDisplay(); nsCSSPseudoElements::Type pseudoType = aNewStyleContext->GetPseudoType(); if (pseudoType != nsCSSPseudoElements::ePseudo_NotPseudoElement) { if (pseudoType != nsCSSPseudoElements::ePseudo_before && pseudoType != nsCSSPseudoElements::ePseudo_after) { return nullptr; } NS_ASSERTION((pseudoType == nsCSSPseudoElements::ePseudo_before && aElement->Tag() == nsGkAtoms::mozgeneratedcontentbefore) || (pseudoType == nsCSSPseudoElements::ePseudo_after && aElement->Tag() == nsGkAtoms::mozgeneratedcontentafter), "Unexpected aElement coming through"); // Else the element we want to use from now on is the element the // :before or :after is attached to. aElement = aElement->GetParent()->AsElement(); } AnimationPlayerCollection* collection = GetElementTransitions(aElement, pseudoType, false); if (!collection && disp->mTransitionPropertyCount == 1 && disp->mTransitions[0].GetDelay() == 0.0f && disp->mTransitions[0].GetDuration() == 0.0f) { return nullptr; } if (aNewStyleContext->PresContext()->IsProcessingAnimationStyleChange()) { return nullptr; } if (aNewStyleContext->GetParent() && aNewStyleContext->GetParent()->HasPseudoElementData()) { // Ignore transitions on things that inherit properties from // pseudo-elements. // FIXME (Bug 522599): Add tests for this. return nullptr; } NS_WARN_IF_FALSE(!nsLayoutUtils::AreAsyncAnimationsEnabled() || mPresContext->RestyleManager()-> ThrottledAnimationStyleIsUpToDate(), "throttled animations not up to date"); // 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 |whichStarted|). bool startedAny = false; nsCSSPropertySet whichStarted; for (uint32_t i = disp->mTransitionPropertyCount; i-- != 0; ) { const StyleTransition& t = disp->mTransitions[i]; // Check delay and duration first, since they default to zero, and // when they're both zero, we can ignore the transition. if (t.GetDelay() != 0.0f || t.GetDuration() != 0.0f) { // 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. nsCSSProperty property = t.GetProperty(); 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 (nsCSSProperty p = nsCSSProperty(0); p < eCSSProperty_COUNT_no_shorthands; p = nsCSSProperty(p + 1)) { ConsiderStartingTransition(p, t, aElement, collection, aOldStyleContext, aNewStyleContext, &startedAny, &whichStarted); } } else if (nsCSSProps::IsShorthand(property)) { CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(subprop, property) { ConsiderStartingTransition(*subprop, t, aElement, collection, aOldStyleContext, aNewStyleContext, &startedAny, &whichStarted); } } else { ConsiderStartingTransition(property, t, aElement, collection, aOldStyleContext, aNewStyleContext, &startedAny, &whichStarted); } } } // Stop any transitions for properties that are no longer in // 'transition-property'. // Also stop any transitions for properties that just changed (and are // still in the set of properties to transition), but we didn't just // start the transition because delay and duration are both zero. if (collection) { bool checkProperties = disp->mTransitions[0].GetProperty() != eCSSPropertyExtra_all_properties; nsCSSPropertySet allTransitionProperties; if (checkProperties) { for (uint32_t i = disp->mTransitionPropertyCount; i-- != 0; ) { const StyleTransition& t = disp->mTransitions[i]; // FIXME: Would be good to find a way to share code between this // interpretation of transition-property and the one above. nsCSSProperty property = t.GetProperty(); 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 (nsCSSProperty p = nsCSSProperty(0); p < eCSSProperty_COUNT_no_shorthands; p = nsCSSProperty(p + 1)) { allTransitionProperties.AddProperty(p); } } else if (nsCSSProps::IsShorthand(property)) { CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(subprop, property) { allTransitionProperties.AddProperty(*subprop); } } else { allTransitionProperties.AddProperty(property); } } } AnimationPlayerPtrArray& players = collection->mPlayers; size_t i = players.Length(); NS_ABORT_IF_FALSE(i != 0, "empty transitions list?"); StyleAnimationValue currentValue; do { --i; AnimationPlayer* player = players[i]; dom::Animation* anim = player->GetSource(); MOZ_ASSERT(anim && anim->Properties().Length() == 1, "Should have one animation property for a transition"); MOZ_ASSERT(anim && anim->Properties()[0].mSegments.Length() == 1, "Animation property should have one segment for a transition"); const AnimationProperty& prop = anim->Properties()[0]; const AnimationPropertySegment& segment = prop.mSegments[0]; // properties no longer in 'transition-property' if ((checkProperties && !allTransitionProperties.HasProperty(prop.mProperty)) || // properties whose computed values changed but delay and // duration are both zero !ExtractComputedValueForTransition(prop.mProperty, aNewStyleContext, currentValue) || currentValue != segment.mToValue) { // stop the transition players.RemoveElementAt(i); collection->UpdateAnimationGeneration(mPresContext); } } while (i != 0); if (players.IsEmpty()) { collection->Destroy(); collection = nullptr; } } if (!startedAny) { return nullptr; } NS_ABORT_IF_FALSE(collection, "must have element transitions if we started " "any transitions"); // In the CSS working group discussion (2009 Jul 15 telecon, // http://www.w3.org/mid/4A5E1470.4030904@inkedblade.net ) of // http://lists.w3.org/Archives/Public/www-style/2009Jun/0121.html , // the working group decided that a transition property on an // element should not cause any transitions if the property change // is itself inheriting a value that is transitioning on an // ancestor. So, to get the correct behavior, we continue the // restyle that caused this transition using a "covering" rule that // covers up any changes on which we started transitions, so that // descendants don't start their own transitions. (In the case of // negative transition delay, this covering rule produces different // results than applying the transition rule immediately would). // Our caller is responsible for restyling again using this covering // rule. nsRefPtr coverRule = new css::AnimValuesStyleRule; AnimationPlayerPtrArray& players = collection->mPlayers; for (size_t i = 0, i_end = players.Length(); i < i_end; ++i) { dom::Animation* anim = players[i]->GetSource(); MOZ_ASSERT(anim && anim->Properties().Length() == 1, "Should have one animation property for a transition"); MOZ_ASSERT(anim && anim->Properties()[0].mSegments.Length() == 1, "Animation property should have one segment for a transition"); AnimationProperty& prop = anim->Properties()[0]; AnimationPropertySegment& segment = prop.mSegments[0]; if (whichStarted.HasProperty(prop.mProperty)) { coverRule->AddValue(prop.mProperty, segment.mFromValue); } } collection->mStyleRule = nullptr; return coverRule.forget(); } void nsTransitionManager::ConsiderStartingTransition( nsCSSProperty aProperty, const StyleTransition& aTransition, dom::Element* aElement, AnimationPlayerCollection*& aElementTransitions, nsStyleContext* aOldStyleContext, nsStyleContext* aNewStyleContext, bool* aStartedAny, nsCSSPropertySet* aWhichStarted) { // IsShorthand itself will assert if aProperty is not a property. NS_ABORT_IF_FALSE(!nsCSSProps::IsShorthand(aProperty), "property out of range"); NS_ASSERTION(!aElementTransitions || aElementTransitions->mElement == aElement, "Element mismatch"); if (aWhichStarted->HasProperty(aProperty)) { // A later item in transition-property already started a // transition for this property, so we ignore this one. // See comment above and // http://lists.w3.org/Archives/Public/www-style/2009Aug/0109.html . return; } if (nsCSSProps::kAnimTypeTable[aProperty] == eStyleAnimType_None) { return; } dom::AnimationTimeline* timeline = aElement->OwnerDoc()->Timeline(); StyleAnimationValue startValue, endValue, dummyValue; bool haveValues = ExtractComputedValueForTransition(aProperty, aOldStyleContext, startValue) && ExtractComputedValueForTransition(aProperty, aNewStyleContext, endValue); bool haveChange = startValue != endValue; bool shouldAnimate = haveValues && haveChange && // Check that we can interpolate between these values // (If this is ever a performance problem, we could add a // CanInterpolate method, but it seems fine for now.) StyleAnimationValue::Interpolate(aProperty, startValue, endValue, 0.5, dummyValue); bool haveCurrentTransition = false; size_t currentIndex = nsTArray::NoIndex; const ElementPropertyTransition *oldPT = nullptr; if (aElementTransitions) { AnimationPlayerPtrArray& players = aElementTransitions->mPlayers; for (size_t i = 0, i_end = players.Length(); i < i_end; ++i) { MOZ_ASSERT(players[i]->GetSource() && players[i]->GetSource()->Properties().Length() == 1, "Should have one animation property for a transition"); if (players[i]->GetSource()->Properties()[0].mProperty == aProperty) { haveCurrentTransition = true; currentIndex = i; oldPT = players[currentIndex]->GetSource()->AsTransition(); 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! MOZ_ASSERT(!oldPT || oldPT->Properties()[0].mSegments.Length() == 1, "Should have one animation property segment for a transition"); if (haveCurrentTransition && haveValues && oldPT->Properties()[0].mSegments[0].mToValue == endValue) { // WalkTransitionRule already called RestyleForAnimation. return; } nsPresContext *presContext = aNewStyleContext->PresContext(); 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. AnimationPlayerPtrArray& players = aElementTransitions->mPlayers; oldPT = nullptr; // Clear pointer so it doesn't dangle players.RemoveElementAt(currentIndex); aElementTransitions->UpdateAnimationGeneration(mPresContext); if (players.IsEmpty()) { aElementTransitions->Destroy(); // |aElementTransitions| is now a dangling pointer! aElementTransitions = nullptr; } // WalkTransitionRule already called RestyleForAnimation. } return; } const nsTimingFunction &tf = aTransition.GetTimingFunction(); float delay = aTransition.GetDelay(); float duration = aTransition.GetDuration(); if (duration < 0.0) { // The spec says a negative duration is treated as zero. duration = 0.0; } StyleAnimationValue startForReversingTest = startValue; double reversePortion = 1.0; // If the new transition reverses an existing one, we'll need to // handle the timing differently. if (haveCurrentTransition && !oldPT->IsFinishedTransition() && 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->Properties()[0].mSegments[0].mToValue; reversePortion = valuePortion; } AnimationTiming timing; timing.mIterationDuration = TimeDuration::FromMilliseconds(duration); timing.mDelay = TimeDuration::FromMilliseconds(delay); timing.mIterationCount = 1; timing.mDirection = NS_STYLE_ANIMATION_DIRECTION_NORMAL; timing.mFillMode = NS_STYLE_ANIMATION_FILL_MODE_BACKWARDS; nsRefPtr pt = new ElementPropertyTransition(aElement->OwnerDoc(), timing); pt->mStartForReversingTest = startForReversingTest; pt->mReversePortion = reversePortion; AnimationProperty& prop = *pt->Properties().AppendElement(); prop.mProperty = aProperty; AnimationPropertySegment& segment = *prop.mSegments.AppendElement(); segment.mFromValue = startValue; segment.mToValue = endValue; segment.mFromKey = 0; segment.mToKey = 1; segment.mTimingFunction.Init(tf); nsRefPtr player = new dom::AnimationPlayer(timeline); player->mStartTime = timeline->GetCurrentTimeStamp(); player->SetSource(pt); if (!aElementTransitions) { aElementTransitions = GetElementTransitions(aElement, aNewStyleContext->GetPseudoType(), true); if (!aElementTransitions) { NS_WARNING("allocating CommonAnimationManager failed"); return; } } AnimationPlayerPtrArray& players = aElementTransitions->mPlayers; #ifdef DEBUG for (size_t i = 0, i_end = players.Length(); i < i_end; ++i) { NS_ABORT_IF_FALSE(players[i]->GetSource() && players[i]->GetSource()->Properties().Length() == 1, "Should have one animation property for a transition"); NS_ABORT_IF_FALSE(i == currentIndex || (players[i]->GetSource() && players[i]->GetSource()->Properties()[0].mProperty != aProperty), "duplicate transitions for property"); } #endif if (haveCurrentTransition) { players[currentIndex] = player; } else { if (!players.AppendElement(player)) { NS_WARNING("out of memory"); return; } } aElementTransitions->UpdateAnimationGeneration(mPresContext); aElementTransitions->PostRestyleForAnimation(presContext); *aStartedAny = true; aWhichStarted->AddProperty(aProperty); } AnimationPlayerCollection* nsTransitionManager::GetElementTransitions( dom::Element *aElement, nsCSSPseudoElements::Type aPseudoType, bool aCreateIfNeeded) { if (!aCreateIfNeeded && PR_CLIST_IS_EMPTY(&mElementCollections)) { // Early return for the most common case. return nullptr; } nsIAtom *propName; if (aPseudoType == nsCSSPseudoElements::ePseudo_NotPseudoElement) { propName = nsGkAtoms::transitionsProperty; } else if (aPseudoType == nsCSSPseudoElements::ePseudo_before) { propName = nsGkAtoms::transitionsOfBeforeProperty; } else if (aPseudoType == nsCSSPseudoElements::ePseudo_after) { propName = nsGkAtoms::transitionsOfAfterProperty; } else { NS_ASSERTION(!aCreateIfNeeded, "should never try to create transitions for pseudo " "other than :before or :after"); return nullptr; } AnimationPlayerCollection* collection = static_cast(aElement->GetProperty(propName)); if (!collection && aCreateIfNeeded) { // FIXME: Consider arena-allocating? collection = new AnimationPlayerCollection(aElement, propName, this, mPresContext->RefreshDriver()->MostRecentRefresh()); nsresult rv = aElement->SetProperty(propName, collection, &AnimationPlayerCollection::PropertyDtor, false); if (NS_FAILED(rv)) { NS_WARNING("SetProperty failed"); delete collection; return nullptr; } if (propName == nsGkAtoms::transitionsProperty) { aElement->SetMayHaveAnimations(); } AddElementCollection(collection); } return collection; } /* * nsIStyleRuleProcessor implementation */ void nsTransitionManager::WalkTransitionRule( ElementDependentRuleProcessorData* aData, nsCSSPseudoElements::Type aPseudoType) { AnimationPlayerCollection* collection = GetElementTransitions(aData->mElement, aPseudoType, false); if (!collection) { return; } if (!mPresContext->IsDynamic()) { // For print or print preview, ignore animations. return; } if (aData->mPresContext->IsProcessingRestyles() && !aData->mPresContext->IsProcessingAnimationStyleChange()) { // If we're processing a normal style change rather than one from // animation, don't add the transition rule. This allows us to // compute the new style value rather than having the transition // override it, so that we can start transitioning differently. // We need to immediately restyle with animation // after doing this. collection->PostRestyleForAnimation(mPresContext); return; } collection->mNeedsRefreshes = true; collection->EnsureStyleRuleFor( aData->mPresContext->RefreshDriver()->MostRecentRefresh(), EnsureStyleRule_IsNotThrottled); if (collection->mStyleRule) { aData->mRuleWalker->Forward(collection->mStyleRule); } } /* virtual */ void nsTransitionManager::RulesMatching(ElementRuleProcessorData* aData) { NS_ABORT_IF_FALSE(aData->mPresContext == mPresContext, "pres context mismatch"); WalkTransitionRule(aData, nsCSSPseudoElements::ePseudo_NotPseudoElement); } /* virtual */ void nsTransitionManager::RulesMatching(PseudoElementRuleProcessorData* aData) { NS_ABORT_IF_FALSE(aData->mPresContext == mPresContext, "pres context mismatch"); // Note: If we're the only thing keeping a pseudo-element frame alive // (per ProbePseudoStyleContext), we still want to keep it alive, so // this is ok. WalkTransitionRule(aData, aData->mPseudoType); } /* virtual */ void nsTransitionManager::RulesMatching(AnonBoxRuleProcessorData* aData) { } #ifdef MOZ_XUL /* virtual */ void nsTransitionManager::RulesMatching(XULTreeRuleProcessorData* aData) { } #endif /* virtual */ size_t nsTransitionManager::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const { return CommonAnimationManager::SizeOfExcludingThis(aMallocSizeOf); } /* virtual */ size_t nsTransitionManager::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const { return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf); } struct TransitionEventInfo { nsCOMPtr mElement; InternalTransitionEvent mEvent; TransitionEventInfo(nsIContent *aElement, nsCSSProperty aProperty, TimeDuration aDuration, const nsAString& aPseudoElement) : mElement(aElement) , mEvent(true, NS_TRANSITION_END) { // XXX Looks like nobody initialize WidgetEvent::time mEvent.propertyName = NS_ConvertUTF8toUTF16(nsCSSProps::GetStringValue(aProperty)); mEvent.elapsedTime = aDuration.ToSeconds(); mEvent.pseudoElement = aPseudoElement; } // InternalTransitionEvent doesn't support copy-construction, so we need // to ourselves in order to work with nsTArray TransitionEventInfo(const TransitionEventInfo &aOther) : mElement(aOther.mElement) , mEvent(true, NS_TRANSITION_END) { mEvent.AssignTransitionEventData(aOther.mEvent, false); } }; /* virtual */ void nsTransitionManager::WillRefresh(mozilla::TimeStamp aTime) { NS_ABORT_IF_FALSE(mPresContext, "refresh driver should not notify additional observers " "after pres context has been destroyed"); if (!mPresContext->GetPresShell()) { // Someone might be keeping mPresContext alive past the point // where it has been torn down; don't bother doing anything in // this case. But do get rid of all our transitions so we stop // triggering refreshes. RemoveAllElementCollections(); return; } FlushTransitions(Can_Throttle); } void nsTransitionManager::FlushTransitions(FlushFlags aFlags) { if (PR_CLIST_IS_EMPTY(&mElementCollections)) { // no transitions, leave early return; } nsTArray events; TimeStamp now = mPresContext->RefreshDriver()->MostRecentRefresh(); bool didThrottle = false; // Trim transitions that have completed, post restyle events for frames that // are still transitioning, and start transitions with delays. { PRCList *next = PR_LIST_HEAD(&mElementCollections); while (next != &mElementCollections) { AnimationPlayerCollection* collection = static_cast(next); next = PR_NEXT_LINK(next); collection->Tick(); bool canThrottleTick = aFlags == Can_Throttle && collection->CanPerformOnCompositorThread( AnimationPlayerCollection::CanAnimateFlags(0)) && collection->CanThrottleAnimation(now); NS_ABORT_IF_FALSE(collection->mElement->GetCrossShadowCurrentDoc() == mPresContext->Document(), "Element::UnbindFromTree should have " "destroyed the element transitions object"); size_t i = collection->mPlayers.Length(); NS_ABORT_IF_FALSE(i != 0, "empty transitions list?"); bool transitionStartedOrEnded = false; do { --i; AnimationPlayer* player = collection->mPlayers[i]; if (player->GetSource()->IsFinishedTransition()) { // Actually remove transitions one throttle-able cycle after their // completion. We only clear on a throttle-able cycle because that // means it is a regular restyle tick and thus it is safe to discard // the transition. If the flush is not throttle-able, we might still // have new transitions left to process. See comment below. if (aFlags == Can_Throttle) { collection->mPlayers.RemoveElementAt(i); } } else { MOZ_ASSERT(player->GetSource(), "Transitions should have source content"); ComputedTiming computedTiming = player->GetSource()->GetComputedTiming(); if (computedTiming.mPhase == ComputedTiming::AnimationPhase_After) { MOZ_ASSERT(player->GetSource()->Properties().Length() == 1, "Should have one animation property for a transition"); nsCSSProperty prop = player->GetSource()->Properties()[0].mProperty; if (nsCSSProps::PropHasFlags(prop, CSS_PROPERTY_REPORT_OTHER_NAME)) { prop = nsCSSProps::OtherNameFor(prop); } TimeDuration duration = player->GetSource()->Timing().mIterationDuration; events.AppendElement( TransitionEventInfo(collection->mElement, prop, duration, collection->PseudoElement())); // Leave this transition in the list for one more refresh // cycle, since we haven't yet processed its style change, and // if we also have (already, or will have from processing // transitionend events or other refresh driver notifications) // a non-animation style change that would affect it, we need // to know not to start a new transition for the transition // from the almost-completed value to the final value. player->GetSource()->SetIsFinishedTransition(); collection->UpdateAnimationGeneration(mPresContext); transitionStartedOrEnded = true; } else if ((computedTiming.mPhase == ComputedTiming::AnimationPhase_Active) && canThrottleTick && !player->mIsRunningOnCompositor) { // Start a transition with a delay where we should start the // transition proper. collection->UpdateAnimationGeneration(mPresContext); transitionStartedOrEnded = true; } } } while (i != 0); // We need to restyle even if the transition rule no longer // applies (in which case we just made it not apply). MOZ_ASSERT(collection->mElementProperty == nsGkAtoms::transitionsProperty || collection->mElementProperty == nsGkAtoms::transitionsOfBeforeProperty || collection->mElementProperty == nsGkAtoms::transitionsOfAfterProperty, "Unexpected element property; might restyle too much"); if (!canThrottleTick || transitionStartedOrEnded) { collection->PostRestyleForAnimation(mPresContext); } else { didThrottle = true; } if (collection->mPlayers.IsEmpty()) { collection->Destroy(); // |collection| is now a dangling pointer! collection = nullptr; } } } if (didThrottle) { mPresContext->Document()->SetNeedStyleFlush(); } for (uint32_t i = 0, i_end = events.Length(); i < i_end; ++i) { TransitionEventInfo &info = events[i]; EventDispatcher::Dispatch(info.mElement, mPresContext, &info.mEvent); if (!mPresContext) { break; } } }