gecko/layout/style/nsTransitionManager.cpp
2013-10-22 12:30:45 +02:00

1157 lines
42 KiB
C++

/* -*- 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 "nsStyleAnimation.h"
#include "nsEventDispatcher.h"
#include "mozilla/ContentEvents.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 namespace mozilla;
using namespace mozilla::layers;
using namespace mozilla::css;
ElementTransitions::ElementTransitions(mozilla::dom::Element *aElement,
nsIAtom *aElementProperty,
nsTransitionManager *aTransitionManager,
TimeStamp aNow)
: CommonElementAnimationData(aElement, aElementProperty, aTransitionManager)
, mFlushGeneration(aNow)
{
}
double
ElementPropertyTransition::ValuePortionFor(TimeStamp aRefreshTime) const
{
// Set |timePortion| to the portion of the way we are through the time
// input to the transition's timing function (always within the range
// 0-1).
double duration = mDuration.ToSeconds();
NS_ABORT_IF_FALSE(duration >= 0.0, "negative duration forbidden");
double timePortion;
if (IsRemovedSentinel()) {
// The transition is being removed, but we still want an update so that any
// new transitions start in the right place.
timePortion = 1.0;
} else if (duration == 0.0) {
// When duration is zero, we can still have a transition when delay
// is nonzero. mStartTime already incorporates delay.
if (aRefreshTime >= mStartTime) {
timePortion = 1.0;
} else {
timePortion = 0.0;
}
} else {
timePortion = (aRefreshTime - mStartTime).ToSeconds() / duration;
if (timePortion < 0.0)
timePortion = 0.0; // use start value during transition-delay
if (timePortion > 1.0)
timePortion = 1.0; // we might be behind on flushing
}
return mTimingFunction.GetValue(timePortion);
}
static void
ElementTransitionsPropertyDtor(void *aObject,
nsIAtom *aPropertyName,
void *aPropertyValue,
void *aData)
{
ElementTransitions *et = static_cast<ElementTransitions*>(aPropertyValue);
#ifdef DEBUG
NS_ABORT_IF_FALSE(!et->mCalledPropertyDtor, "can't call dtor twice");
et->mCalledPropertyDtor = true;
#endif
delete et;
}
void
ElementTransitions::EnsureStyleRuleFor(TimeStamp aRefreshTime)
{
if (!mStyleRule || mStyleRuleRefreshTime != aRefreshTime) {
mStyleRule = new css::AnimValuesStyleRule();
mStyleRuleRefreshTime = aRefreshTime;
for (uint32_t i = 0, i_end = mPropertyTransitions.Length(); i < i_end; ++i)
{
ElementPropertyTransition &pt = mPropertyTransitions[i];
if (pt.IsRemovedSentinel()) {
continue;
}
nsStyleAnimation::Value *val = mStyleRule->AddEmptyValue(pt.mProperty);
double valuePortion = pt.ValuePortionFor(aRefreshTime);
#ifdef DEBUG
bool ok =
#endif
nsStyleAnimation::Interpolate(pt.mProperty,
pt.mStartValue, pt.mEndValue,
valuePortion, *val);
NS_ABORT_IF_FALSE(ok, "could not interpolate values");
}
}
}
bool
ElementPropertyTransition::IsRunningAt(TimeStamp aTime) const {
return !IsRemovedSentinel() &&
mStartTime <= aTime &&
aTime < mStartTime + mDuration;
}
bool
ElementTransitions::HasAnimationOfProperty(nsCSSProperty aProperty) const
{
for (uint32_t tranIdx = mPropertyTransitions.Length(); tranIdx-- != 0; ) {
const ElementPropertyTransition& pt = mPropertyTransitions[tranIdx];
if (aProperty == pt.mProperty && !pt.IsRemovedSentinel()) {
return true;
}
}
return false;
}
bool
ElementTransitions::CanPerformOnCompositorThread(CanAnimateFlags aFlags) const
{
nsIFrame* frame = nsLayoutUtils::GetStyleFrame(mElement);
if (!frame) {
return false;
}
if (mElementProperty != nsGkAtoms::transitionsProperty) {
if (nsLayoutUtils::IsAnimationLoggingEnabled()) {
nsCString message;
message.AppendLiteral("Gecko bug: Async transition of pseudoelements not supported. See bug 771367");
LogAsyncAnimationFailure(message, mElement);
}
return false;
}
TimeStamp now = frame->PresContext()->RefreshDriver()->MostRecentRefresh();
for (uint32_t i = 0, i_end = mPropertyTransitions.Length(); i < i_end; ++i) {
const ElementPropertyTransition& pt = mPropertyTransitions[i];
if (css::IsGeometricProperty(pt.mProperty) && pt.IsRunningAt(now)) {
aFlags = CanAnimateFlags(aFlags | CanAnimate_HasGeometricProperty);
break;
}
}
bool hasOpacity = false;
bool hasTransform = false;
bool existsProperty = false;
for (uint32_t i = 0, i_end = mPropertyTransitions.Length(); i < i_end; ++i) {
const ElementPropertyTransition& pt = mPropertyTransitions[i];
if (pt.IsRemovedSentinel()) {
continue;
}
existsProperty = true;
if (!css::CommonElementAnimationData::CanAnimatePropertyOnCompositor(mElement,
pt.mProperty,
aFlags) ||
!css::CommonElementAnimationData::IsCompositorAnimationDisabledForFrame(frame)) {
return false;
}
if (pt.mProperty == eCSSProperty_opacity) {
hasOpacity = true;
} else if (pt.mProperty == eCSSProperty_transform) {
hasTransform = true;
}
}
// No properties to animate
if (!existsProperty) {
return false;
}
// This transition can be done on the compositor. Mark the frame as active, in
// case we are able to throttle this transition.
if (hasOpacity) {
frame->MarkLayersActive(nsChangeHint_UpdateOpacityLayer);
}
if (hasTransform) {
frame->MarkLayersActive(nsChangeHint_UpdateTransformLayer);
}
return true;
}
/*****************************************************************************
* nsTransitionManager *
*****************************************************************************/
// reparent :before and :after pseudo elements of aElement
static void ReparentBeforeAndAfter(dom::Element* aElement,
nsIFrame* aPrimaryFrame,
nsStyleContext* aNewStyle,
nsStyleSet* aStyleSet)
{
if (nsIFrame* before = nsLayoutUtils::GetBeforeFrame(aPrimaryFrame)) {
nsRefPtr<nsStyleContext> beforeStyle =
aStyleSet->ReparentStyleContext(before->StyleContext(),
aNewStyle, aElement);
before->SetStyleContext(beforeStyle);
}
if (nsIFrame* after = nsLayoutUtils::GetBeforeFrame(aPrimaryFrame)) {
nsRefPtr<nsStyleContext> afterStyle =
aStyleSet->ReparentStyleContext(after->StyleContext(),
aNewStyle, aElement);
after->SetStyleContext(afterStyle);
}
}
// Ensure that the next repaint rebuilds the layer tree for aFrame. That
// means that changes to animations on aFrame's layer are propagated to
// the compositor, which is needed for correct behaviour of new
// transitions.
static void
ForceLayerRerendering(nsIFrame* aFrame, CommonElementAnimationData* aData)
{
if (aData->HasAnimationOfProperty(eCSSProperty_opacity)) {
if (Layer* layer = FrameLayerBuilder::GetDedicatedLayer(
aFrame, nsDisplayItem::TYPE_OPACITY)) {
layer->RemoveUserData(nsIFrame::LayerIsPrerenderedDataKey());
}
}
if (aData->HasAnimationOfProperty(eCSSProperty_transform)) {
if (Layer* layer = FrameLayerBuilder::GetDedicatedLayer(
aFrame, nsDisplayItem::TYPE_TRANSFORM)) {
layer->RemoveUserData(nsIFrame::LayerIsPrerenderedDataKey());
}
}
}
nsStyleContext*
nsTransitionManager::UpdateThrottledStyle(dom::Element* aElement,
nsStyleContext* aParentStyle,
nsStyleChangeList& aChangeList)
{
NS_ASSERTION(GetElementTransitions(aElement,
nsCSSPseudoElements::ePseudo_NotPseudoElement,
false), "element not transitioning");
nsIFrame* primaryFrame = nsLayoutUtils::GetStyleFrame(aElement);
if (!primaryFrame) {
return nullptr;
}
nsStyleContext* oldStyle = primaryFrame->StyleContext();
nsRuleNode* ruleNode = oldStyle->RuleNode();
nsTArray<nsStyleSet::RuleAndLevel> rules;
do {
if (ruleNode->IsRoot()) {
break;
}
nsStyleSet::RuleAndLevel curRule;
curRule.mLevel = ruleNode->GetLevel();
if (curRule.mLevel == nsStyleSet::eAnimationSheet) {
ElementAnimations* ea =
mPresContext->AnimationManager()->GetElementAnimations(aElement,
oldStyle->GetPseudoType(),
false);
NS_ASSERTION(ea, "Rule has level eAnimationSheet without animation on manager");
mPresContext->AnimationManager()->EnsureStyleRuleFor(ea);
curRule.mRule = ea->mStyleRule;
// FIXME: maybe not needed anymore:
ForceLayerRerendering(primaryFrame, ea);
} else if (curRule.mLevel == nsStyleSet::eTransitionSheet) {
ElementTransitions *et =
GetElementTransitions(aElement, oldStyle->GetPseudoType(), false);
NS_ASSERTION(et, "Rule has level eTransitionSheet without transition on manager");
et->EnsureStyleRuleFor(mPresContext->RefreshDriver()->MostRecentRefresh());
curRule.mRule = et->mStyleRule;
// FIXME: maybe not needed anymore:
ForceLayerRerendering(primaryFrame, et);
} else {
curRule.mRule = ruleNode->GetRule();
}
if (curRule.mRule) {
rules.AppendElement(curRule);
}
} while ((ruleNode = ruleNode->GetParent()));
nsRefPtr<nsStyleContext> newStyle = mPresContext->PresShell()->StyleSet()->
ResolveStyleForRules(aParentStyle, oldStyle, rules);
// We absolutely must call CalcStyleDifference in order to ensure the
// new context has all the structs cached that the old context had.
// We also need it for processing of the changes.
nsChangeHint styleChange =
oldStyle->CalcStyleDifference(newStyle, nsChangeHint(0));
aChangeList.AppendChange(primaryFrame, primaryFrame->GetContent(),
styleChange);
primaryFrame->SetStyleContext(newStyle);
ReparentBeforeAndAfter(aElement, primaryFrame, newStyle, mPresContext->PresShell()->StyleSet());
return newStyle;
}
void
nsTransitionManager::UpdateThrottledStylesForSubtree(nsIContent* aContent,
nsStyleContext* aParentStyle,
nsStyleChangeList& aChangeList)
{
dom::Element* element;
if (aContent->IsElement()) {
element = aContent->AsElement();
} else {
element = nullptr;
}
nsRefPtr<nsStyleContext> newStyle;
ElementTransitions* et;
if (element &&
(et = GetElementTransitions(element,
nsCSSPseudoElements::ePseudo_NotPseudoElement,
false))) {
// re-resolve our style
newStyle = UpdateThrottledStyle(element, aParentStyle, aChangeList);
// remove the current transition from the working set
et->mFlushGeneration = mPresContext->RefreshDriver()->MostRecentRefresh();
} else {
// reparent the element's style
nsStyleSet* styleSet = mPresContext->PresShell()->StyleSet();
nsIFrame* primaryFrame = nsLayoutUtils::GetStyleFrame(aContent);
if (!primaryFrame) {
return;
}
newStyle = styleSet->ReparentStyleContext(primaryFrame->StyleContext(),
aParentStyle, element);
primaryFrame->SetStyleContext(newStyle);
ReparentBeforeAndAfter(element, primaryFrame, newStyle, styleSet);
}
// walk the children
if (newStyle) {
for (nsIContent *child = aContent->GetFirstChild(); child;
child = child->GetNextSibling()) {
UpdateThrottledStylesForSubtree(child, newStyle, aChangeList);
}
}
}
void
nsTransitionManager::UpdateAllThrottledStyles()
{
if (PR_CLIST_IS_EMPTY(&mElementData)) {
// no throttled transitions, leave early
mPresContext->TickLastUpdateThrottledStyle();
return;
}
if (mPresContext->ThrottledStyleIsUpToDate()) {
// throttled transitions are up to date, leave early
return;
}
mPresContext->TickLastUpdateThrottledStyle();
TimeStamp now = mPresContext->RefreshDriver()->MostRecentRefresh();
nsStyleChangeList changeList;
// update each transitioning element by finding its root-most ancestor with a
// transition, and flushing the style on that ancestor and all its descendants
PRCList *next = PR_LIST_HEAD(&mElementData);
while (next != &mElementData) {
ElementTransitions* et = static_cast<ElementTransitions*>(next);
next = PR_NEXT_LINK(next);
if (et->mFlushGeneration == now) {
// this element has been ticked already
continue;
}
// element is initialised to the starting element (i.e., one we know has
// a transition) and ends up with the root-most transitioning ancestor,
// that is, the element where we begin updates.
dom::Element* element = et->mElement;
// make a list of ancestors
nsTArray<dom::Element*> ancestors;
do {
ancestors.AppendElement(element);
} while ((element = element->GetParentElement()));
// walk down the ancestors until we find one with a throttled transition
for (int32_t i = ancestors.Length() - 1; i >= 0; --i) {
if (GetElementTransitions(ancestors[i],
nsCSSPseudoElements::ePseudo_NotPseudoElement,
false)) {
element = ancestors[i];
break;
}
}
nsIFrame* primaryFrame;
if (element &&
(primaryFrame = nsLayoutUtils::GetStyleFrame(element))) {
UpdateThrottledStylesForSubtree(element,
primaryFrame->StyleContext()->GetParent(), changeList);
}
}
RestyleManager* restyleManager = mPresContext->RestyleManager();
restyleManager->ProcessRestyledFrames(changeList);
restyleManager->FlushOverflowChangedTracker();
}
void
nsTransitionManager::ElementDataRemoved()
{
// If we have no transitions or animations left, remove ourselves from
// the refresh driver.
if (PR_CLIST_IS_EMPTY(&mElementData)) {
mPresContext->RefreshDriver()->RemoveRefreshObserver(this, Flush_Style);
}
}
void
nsTransitionManager::AddElementData(CommonElementAnimationData* aData)
{
if (PR_CLIST_IS_EMPTY(&mElementData)) {
// We need to observe the refresh driver.
nsRefreshDriver *rd = mPresContext->RefreshDriver();
rd->AddRefreshObserver(this, Flush_Style);
}
PR_INSERT_BEFORE(aData, &mElementData);
}
already_AddRefed<nsIStyleRule>
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 (!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();
}
ElementTransitions *et =
GetElementTransitions(aElement, pseudoType, false);
if (!et &&
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->ThrottledStyleIsUpToDate(),
"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 nsTransition& 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 == 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, et,
aOldStyleContext, aNewStyleContext,
&startedAny, &whichStarted);
}
} else if (nsCSSProps::IsShorthand(property)) {
CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(subprop, property) {
ConsiderStartingTransition(*subprop, t, aElement, et,
aOldStyleContext, aNewStyleContext,
&startedAny, &whichStarted);
}
} else {
ConsiderStartingTransition(property, t, aElement, et,
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 (et) {
bool checkProperties =
disp->mTransitions[0].GetProperty() != eCSSPropertyExtra_all_properties;
nsCSSPropertySet allTransitionProperties;
if (checkProperties) {
for (uint32_t i = disp->mTransitionPropertyCount; i-- != 0; ) {
const nsTransition& 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 == 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);
}
}
}
nsTArray<ElementPropertyTransition> &pts = et->mPropertyTransitions;
uint32_t i = pts.Length();
NS_ABORT_IF_FALSE(i != 0, "empty transitions list?");
nsStyleAnimation::Value currentValue;
do {
--i;
ElementPropertyTransition &pt = pts[i];
// properties no longer in 'transition-property'
if ((checkProperties &&
!allTransitionProperties.HasProperty(pt.mProperty)) ||
// properties whose computed values changed but delay and
// duration are both zero
!ExtractComputedValueForTransition(pt.mProperty, aNewStyleContext,
currentValue) ||
currentValue != pt.mEndValue) {
// stop the transition
pts.RemoveElementAt(i);
et->UpdateAnimationGeneration(mPresContext);
}
} while (i != 0);
if (pts.IsEmpty()) {
et->Destroy();
et = nullptr;
}
}
if (!startedAny) {
return nullptr;
}
NS_ABORT_IF_FALSE(et, "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<css::AnimValuesStyleRule> coverRule = new css::AnimValuesStyleRule;
nsTArray<ElementPropertyTransition> &pts = et->mPropertyTransitions;
for (uint32_t i = 0, i_end = pts.Length(); i < i_end; ++i) {
ElementPropertyTransition &pt = pts[i];
if (whichStarted.HasProperty(pt.mProperty)) {
coverRule->AddValue(pt.mProperty, pt.mStartValue);
}
}
et->mStyleRule = nullptr;
return coverRule.forget();
}
void
nsTransitionManager::ConsiderStartingTransition(nsCSSProperty aProperty,
const nsTransition& aTransition,
dom::Element* aElement,
ElementTransitions*& 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;
}
ElementPropertyTransition pt;
nsStyleAnimation::Value dummyValue;
bool haveValues =
ExtractComputedValueForTransition(aProperty, aOldStyleContext,
pt.mStartValue) &&
ExtractComputedValueForTransition(aProperty, aNewStyleContext,
pt.mEndValue);
bool haveChange = pt.mStartValue != pt.mEndValue;
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.)
nsStyleAnimation::Interpolate(aProperty, pt.mStartValue, pt.mEndValue,
0.5, dummyValue);
bool haveCurrentTransition = false;
uint32_t currentIndex = nsTArray<ElementPropertyTransition>::NoIndex;
const ElementPropertyTransition *oldPT = nullptr;
if (aElementTransitions) {
nsTArray<ElementPropertyTransition> &pts =
aElementTransitions->mPropertyTransitions;
for (uint32_t i = 0, i_end = pts.Length(); i < i_end; ++i) {
if (pts[i].mProperty == aProperty) {
haveCurrentTransition = true;
currentIndex = i;
oldPT = &aElementTransitions->mPropertyTransitions[currentIndex];
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!
if (haveCurrentTransition && haveValues && oldPT->mEndValue == pt.mEndValue) {
// 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.
nsTArray<ElementPropertyTransition> &pts =
aElementTransitions->mPropertyTransitions;
pts.RemoveElementAt(currentIndex);
aElementTransitions->UpdateAnimationGeneration(mPresContext);
if (pts.IsEmpty()) {
aElementTransitions->Destroy();
// |aElementTransitions| is now a dangling pointer!
aElementTransitions = nullptr;
}
// WalkTransitionRule already called RestyleForAnimation.
}
return;
}
TimeStamp mostRecentRefresh =
presContext->RefreshDriver()->MostRecentRefresh();
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;
}
pt.mStartForReversingTest = pt.mStartValue;
pt.mReversePortion = 1.0;
// If the new transition reverses an existing one, we'll need to
// handle the timing differently.
if (haveCurrentTransition &&
!oldPT->IsRemovedSentinel() &&
oldPT->mStartForReversingTest == pt.mEndValue) {
// Compute the appropriate negative transition-delay such that right
// now we'd end up at the current position.
double valuePortion =
oldPT->ValuePortionFor(mostRecentRefresh) * 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;
pt.mStartForReversingTest = oldPT->mEndValue;
pt.mReversePortion = valuePortion;
}
pt.mProperty = aProperty;
pt.mStartTime = mostRecentRefresh + TimeDuration::FromMilliseconds(delay);
pt.mDuration = TimeDuration::FromMilliseconds(duration);
pt.mTimingFunction.Init(tf);
if (!aElementTransitions) {
aElementTransitions =
GetElementTransitions(aElement, aNewStyleContext->GetPseudoType(),
true);
if (!aElementTransitions) {
NS_WARNING("allocating ElementTransitions failed");
return;
}
}
nsTArray<ElementPropertyTransition> &pts =
aElementTransitions->mPropertyTransitions;
#ifdef DEBUG
for (uint32_t i = 0, i_end = pts.Length(); i < i_end; ++i) {
NS_ABORT_IF_FALSE(i == currentIndex ||
pts[i].mProperty != aProperty,
"duplicate transitions for property");
}
#endif
if (haveCurrentTransition) {
pts[currentIndex] = pt;
} else {
if (!pts.AppendElement(pt)) {
NS_WARNING("out of memory");
return;
}
}
aElementTransitions->UpdateAnimationGeneration(mPresContext);
nsRestyleHint hint =
aNewStyleContext->GetPseudoType() ==
nsCSSPseudoElements::ePseudo_NotPseudoElement ?
eRestyle_Self : eRestyle_Subtree;
presContext->PresShell()->RestyleForAnimation(aElement, hint);
*aStartedAny = true;
aWhichStarted->AddProperty(aProperty);
}
ElementTransitions*
nsTransitionManager::GetElementTransitions(dom::Element *aElement,
nsCSSPseudoElements::Type aPseudoType,
bool aCreateIfNeeded)
{
if (!aCreateIfNeeded && PR_CLIST_IS_EMPTY(&mElementData)) {
// 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;
}
ElementTransitions *et = static_cast<ElementTransitions*>(
aElement->GetProperty(propName));
if (!et && aCreateIfNeeded) {
// FIXME: Consider arena-allocating?
et = new ElementTransitions(aElement, propName, this,
mPresContext->RefreshDriver()->MostRecentRefresh());
nsresult rv = aElement->SetProperty(propName, et,
ElementTransitionsPropertyDtor, false);
if (NS_FAILED(rv)) {
NS_WARNING("SetProperty failed");
delete et;
return nullptr;
}
if (propName == nsGkAtoms::transitionsProperty) {
aElement->SetMayHaveAnimations();
}
AddElementData(et);
}
return et;
}
/*
* nsIStyleRuleProcessor implementation
*/
void
nsTransitionManager::WalkTransitionRule(ElementDependentRuleProcessorData* aData,
nsCSSPseudoElements::Type aPseudoType)
{
ElementTransitions *et =
GetElementTransitions(aData->mElement, aPseudoType, false);
if (!et) {
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.
nsRestyleHint hint =
aPseudoType == nsCSSPseudoElements::ePseudo_NotPseudoElement ?
eRestyle_Self : eRestyle_Subtree;
mPresContext->PresShell()->RestyleForAnimation(aData->mElement, hint);
return;
}
et->EnsureStyleRuleFor(
aData->mPresContext->RefreshDriver()->MostRecentRefresh());
aData->mRuleWalker->Forward(et->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<nsIContent> mElement;
InternalTransitionEvent mEvent;
TransitionEventInfo(nsIContent *aElement, nsCSSProperty aProperty,
TimeDuration aDuration, const nsAString& aPseudoElement)
: mElement(aElement),
mEvent(true, NS_TRANSITION_END,
NS_ConvertUTF8toUTF16(nsCSSProps::GetStringValue(aProperty)),
aDuration.ToSeconds(), 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,
aOther.mEvent.propertyName, aOther.mEvent.elapsedTime,
aOther.mEvent.pseudoElement)
{
}
};
/* 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.
RemoveAllElementData();
return;
}
FlushTransitions(Can_Throttle);
}
void
nsTransitionManager::FlushTransitions(FlushFlags aFlags)
{
if (PR_CLIST_IS_EMPTY(&mElementData)) {
// no transitions, leave early
return;
}
nsTArray<TransitionEventInfo> 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(&mElementData);
while (next != &mElementData) {
ElementTransitions *et = static_cast<ElementTransitions*>(next);
next = PR_NEXT_LINK(next);
bool canThrottleTick = aFlags == Can_Throttle &&
et->CanPerformOnCompositorThread(
CommonElementAnimationData::CanAnimateFlags(0)) &&
et->CanThrottleAnimation(now);
NS_ABORT_IF_FALSE(et->mElement->GetCurrentDoc() ==
mPresContext->Document(),
"Element::UnbindFromTree should have "
"destroyed the element transitions object");
uint32_t i = et->mPropertyTransitions.Length();
NS_ABORT_IF_FALSE(i != 0, "empty transitions list?");
bool transitionStartedOrEnded = false;
do {
--i;
ElementPropertyTransition &pt = et->mPropertyTransitions[i];
if (pt.IsRemovedSentinel()) {
// 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) {
et->mPropertyTransitions.RemoveElementAt(i);
}
} else if (pt.mStartTime + pt.mDuration <= now) {
nsCSSProperty prop = pt.mProperty;
if (nsCSSProps::PropHasFlags(prop, CSS_PROPERTY_REPORT_OTHER_NAME))
{
prop = nsCSSProps::OtherNameFor(prop);
}
nsIAtom* ep = et->mElementProperty;
NS_NAMED_LITERAL_STRING(before, "::before");
NS_NAMED_LITERAL_STRING(after, "::after");
events.AppendElement(
TransitionEventInfo(et->mElement, prop, pt.mDuration,
ep == nsGkAtoms::transitionsProperty ?
EmptyString() :
ep == nsGkAtoms::transitionsOfBeforeProperty ?
before :
after));
// 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.
pt.SetRemovedSentinel();
et->UpdateAnimationGeneration(mPresContext);
transitionStartedOrEnded = true;
} else if (pt.mStartTime <= now && canThrottleTick &&
!pt.mIsRunningOnCompositor) {
// Start a transition with a delay where we should start the
// transition proper.
et->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).
NS_ASSERTION(et->mElementProperty == nsGkAtoms::transitionsProperty ||
et->mElementProperty == nsGkAtoms::transitionsOfBeforeProperty ||
et->mElementProperty == nsGkAtoms::transitionsOfAfterProperty,
"Unexpected element property; might restyle too much");
if (!canThrottleTick || transitionStartedOrEnded) {
nsRestyleHint hint = et->mElementProperty == nsGkAtoms::transitionsProperty ?
eRestyle_Self : eRestyle_Subtree;
mPresContext->PresShell()->RestyleForAnimation(et->mElement, hint);
} else {
didThrottle = true;
}
if (et->mPropertyTransitions.IsEmpty()) {
et->Destroy();
// |et| is now a dangling pointer!
et = nullptr;
}
}
}
if (didThrottle) {
mPresContext->Document()->SetNeedStyleFlush();
}
for (uint32_t i = 0, i_end = events.Length(); i < i_end; ++i) {
TransitionEventInfo &info = events[i];
nsEventDispatcher::Dispatch(info.mElement, mPresContext, &info.mEvent);
if (!mPresContext) {
break;
}
}
}