gecko-dev/layout/base/ServoRestyleManager.cpp
Emilio Cobos Álvarez 0eea23decf Bug 1357583: Tidy the PostRestyleEventForCSSRuleChanges API. r=heycam
MozReview-Commit-ID: BtOWWC5knsi
2017-05-29 23:01:50 +02:00

786 lines
27 KiB
C++

/* -*- 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/. */
#include "mozilla/ServoRestyleManager.h"
#include "mozilla/DocumentStyleRootIterator.h"
#include "mozilla/ServoBindings.h"
#include "mozilla/ServoStyleSet.h"
#include "mozilla/Unused.h"
#include "mozilla/dom/ChildIterator.h"
#include "mozilla/dom/ElementInlines.h"
#include "nsBlockFrame.h"
#include "nsBulletFrame.h"
#include "nsPlaceholderFrame.h"
#include "nsContentUtils.h"
#include "nsCSSFrameConstructor.h"
#include "nsPrintfCString.h"
#include "nsRefreshDriver.h"
#include "nsStyleChangeList.h"
using namespace mozilla::dom;
namespace mozilla {
ServoRestyleManager::ServoRestyleManager(nsPresContext* aPresContext)
: RestyleManager(StyleBackendType::Servo, aPresContext)
, mReentrantChanges(nullptr)
{
}
void
ServoRestyleManager::PostRestyleEvent(Element* aElement,
nsRestyleHint aRestyleHint,
nsChangeHint aMinChangeHint)
{
MOZ_ASSERT(!(aMinChangeHint & nsChangeHint_NeutralChange),
"Didn't expect explicit change hints to be neutral!");
if (MOZ_UNLIKELY(IsDisconnected()) ||
MOZ_UNLIKELY(PresContext()->PresShell()->IsDestroying())) {
return;
}
// We allow posting restyles from within change hint handling, but not from
// within the restyle algorithm itself.
MOZ_ASSERT(!ServoStyleSet::IsInServoTraversal());
if (aRestyleHint == 0 && !aMinChangeHint) {
return; // Nothing to do.
}
// Processing change hints sometimes causes new change hints to be generated,
// and very occasionally, additional restyle hints. We collect the change
// hints manually to avoid re-traversing the DOM to find them.
if (mReentrantChanges && !aRestyleHint) {
mReentrantChanges->AppendElement(ReentrantChange { aElement, aMinChangeHint });
return;
}
if (aRestyleHint & ~eRestyle_AllHintsWithAnimations) {
mHaveNonAnimationRestyles = true;
}
Servo_NoteExplicitHints(aElement, aRestyleHint, aMinChangeHint);
}
void
ServoRestyleManager::PostRestyleEventForCSSRuleChanges()
{
mRestyleForCSSRuleChanges = true;
mPresContext->PresShell()->EnsureStyleFlush();
}
/* static */ void
ServoRestyleManager::PostRestyleEventForAnimations(Element* aElement,
nsRestyleHint aRestyleHint)
{
Servo_NoteExplicitHints(aElement, aRestyleHint, nsChangeHint(0));
}
void
ServoRestyleManager::RebuildAllStyleData(nsChangeHint aExtraHint,
nsRestyleHint aRestyleHint)
{
// NOTE(emilio): GeckoRestlyeManager does a sync style flush, which seems not
// to be needed in my testing.
PostRebuildAllStyleDataEvent(aExtraHint, aRestyleHint);
}
void
ServoRestyleManager::PostRebuildAllStyleDataEvent(nsChangeHint aExtraHint,
nsRestyleHint aRestyleHint)
{
StyleSet()->ClearDataAndMarkDeviceDirty();
if (Element* root = mPresContext->Document()->GetRootElement()) {
PostRestyleEvent(root, aRestyleHint, aExtraHint);
}
// TODO(emilio, bz): Extensions can add/remove stylesheets that can affect
// non-inheriting anon boxes. It's not clear if we want to support that, but
// if we do, we need to re-selector-match them here.
}
/* static */ void
ServoRestyleManager::ClearServoDataFromSubtree(Element* aElement)
{
if (!aElement->HasServoData()) {
MOZ_ASSERT(!aElement->HasDirtyDescendantsForServo());
return;
}
StyleChildrenIterator it(aElement);
for (nsIContent* n = it.GetNextChild(); n; n = it.GetNextChild()) {
if (n->IsElement()) {
ClearServoDataFromSubtree(n->AsElement());
}
}
aElement->ClearServoData();
aElement->UnsetHasDirtyDescendantsForServo();
}
/* static */ void
ServoRestyleManager::ClearRestyleStateFromSubtree(Element* aElement)
{
if (aElement->HasDirtyDescendantsForServo()) {
StyleChildrenIterator it(aElement);
for (nsIContent* n = it.GetNextChild(); n; n = it.GetNextChild()) {
if (n->IsElement()) {
ClearRestyleStateFromSubtree(n->AsElement());
}
}
}
Unused << Servo_TakeChangeHint(aElement);
aElement->UnsetHasDirtyDescendantsForServo();
aElement->UnsetFlags(NODE_DESCENDANTS_NEED_FRAMES);
}
/**
* This struct takes care of encapsulating some common state that text nodes may
* need to track during the post-traversal.
*
* This is currently used to properly compute change hints when the parent
* element of this node is a display: contents node, and also to avoid computing
* the style for text children more than once per element.
*/
struct ServoRestyleManager::TextPostTraversalState
{
nsStyleContext& mParentContext;
ServoStyleSet& mStyleSet;
RefPtr<nsStyleContext> mStyle;
bool mShouldPostHints;
bool mShouldComputeHints;
nsChangeHint mComputedHint;
TextPostTraversalState(nsStyleContext& aParentContext,
ServoStyleSet& aStyleSet,
bool aDisplayContentsParentStyleChanged)
: mParentContext(aParentContext)
, mStyleSet(aStyleSet)
, mStyle(nullptr)
, mShouldPostHints(aDisplayContentsParentStyleChanged)
, mShouldComputeHints(aDisplayContentsParentStyleChanged)
, mComputedHint(nsChangeHint_Empty)
{}
nsStyleContext& ComputeStyle(nsIContent* aTextNode)
{
if (!mStyle) {
mStyle = mStyleSet.ResolveStyleForText(aTextNode, &mParentContext);
}
MOZ_ASSERT(mStyle);
return *mStyle;
}
void ComputeHintIfNeeded(nsIContent* aContent,
nsIFrame* aTextFrame,
nsStyleContext& aNewContext,
nsStyleChangeList& aChangeList)
{
MOZ_ASSERT(aTextFrame);
MOZ_ASSERT(aNewContext.GetPseudo() == nsCSSAnonBoxes::mozText);
if (MOZ_LIKELY(!mShouldPostHints)) {
return;
}
nsStyleContext* oldContext = aTextFrame->StyleContext();
MOZ_ASSERT(oldContext->GetPseudo() == nsCSSAnonBoxes::mozText);
// We rely on the fact that all the text children for the same element share
// style to avoid recomputing style differences for all of them.
//
// TODO(emilio): The above may not be true for ::first-{line,letter}, but
// we'll cross that bridge when we support those in stylo.
if (mShouldComputeHints) {
mShouldComputeHints = false;
uint32_t equalStructs, samePointerStructs;
mComputedHint =
oldContext->CalcStyleDifference(&aNewContext,
&equalStructs,
&samePointerStructs);
}
if (mComputedHint) {
aChangeList.AppendChange(aTextFrame, aContent, mComputedHint);
}
}
};
static void
UpdateBlockFramePseudoElements(nsBlockFrame* aFrame,
ServoStyleSet& aStyleSet,
nsStyleChangeList& aChangeList)
{
if (nsBulletFrame* bullet = aFrame->GetBullet()) {
RefPtr<nsStyleContext> newContext =
aStyleSet.ResolvePseudoElementStyle(
aFrame->GetContent()->AsElement(),
bullet->StyleContext()->GetPseudoType(),
aFrame->StyleContext(),
/* aPseudoElement = */ nullptr);
aFrame->UpdateStyleOfOwnedChildFrame(bullet, newContext, aChangeList);
}
}
static void
UpdateBackdropIfNeeded(nsIFrame* aFrame,
ServoStyleSet& aStyleSet,
nsStyleChangeList& aChangeList)
{
const nsStyleDisplay* display = aFrame->StyleContext()->StyleDisplay();
if (display->mTopLayer != NS_STYLE_TOP_LAYER_TOP) {
return;
}
// Elements in the top layer are guaranteed to have absolute or fixed
// position per https://fullscreen.spec.whatwg.org/#new-stacking-layer.
MOZ_ASSERT(display->IsAbsolutelyPositionedStyle());
nsIFrame* backdropPlaceholder =
aFrame->GetChildList(nsIFrame::kBackdropList).FirstChild();
if (!backdropPlaceholder) {
return;
}
MOZ_ASSERT(backdropPlaceholder->IsPlaceholderFrame());
nsIFrame* backdropFrame =
nsPlaceholderFrame::GetRealFrameForPlaceholder(backdropPlaceholder);
MOZ_ASSERT(backdropFrame->IsBackdropFrame());
MOZ_ASSERT(backdropFrame->StyleContext()->GetPseudoType() ==
CSSPseudoElementType::backdrop);
RefPtr<nsStyleContext> newContext =
aStyleSet.ResolvePseudoElementStyle(
aFrame->GetContent()->AsElement(),
CSSPseudoElementType::backdrop,
aFrame->StyleContext(),
/* aPseudoElement = */ nullptr);
aFrame->UpdateStyleOfOwnedChildFrame(backdropFrame,
newContext,
aChangeList);
}
static void
UpdateFramePseudoElementStyles(nsIFrame* aFrame,
ServoStyleSet& aStyleSet,
nsStyleChangeList& aChangeList)
{
if (aFrame->IsFrameOfType(nsIFrame::eBlockFrame)) {
UpdateBlockFramePseudoElements(static_cast<nsBlockFrame*>(aFrame),
aStyleSet,
aChangeList);
}
UpdateBackdropIfNeeded(aFrame, aStyleSet, aChangeList);
}
void
ServoRestyleManager::ProcessPostTraversal(Element* aElement,
nsStyleContext* aParentContext,
ServoStyleSet* aStyleSet,
nsStyleChangeList& aChangeList)
{
nsIFrame* styleFrame = nsLayoutUtils::GetStyleFrame(aElement);
// Grab the change hint from Servo.
nsChangeHint changeHint = Servo_TakeChangeHint(aElement);
// Handle lazy frame construction by posting a reconstruct for any lazily-
// constructed roots.
if (aElement->HasFlag(NODE_NEEDS_FRAME)) {
changeHint |= nsChangeHint_ReconstructFrame;
// The only time the primary frame is non-null is when image maps do hacky
// SetPrimaryFrame calls.
MOZ_ASSERT_IF(styleFrame, styleFrame->IsImageFrame());
styleFrame = nullptr;
}
// Although we shouldn't generate non-ReconstructFrame hints for elements with
// no frames, we can still get them here if they were explicitly posted by
// PostRestyleEvent, such as a RepaintFrame hint when a :link changes to be
// :visited. Skip processing these hints if there is no frame.
if ((styleFrame || (changeHint & nsChangeHint_ReconstructFrame)) && changeHint) {
aChangeList.AppendChange(styleFrame, aElement, changeHint);
}
// If our change hint is reconstruct, we delegate to the frame constructor,
// which consumes the new style and expects the old style to be on the frame.
//
// XXXbholley: We should teach the frame constructor how to clear the dirty
// descendants bit to avoid the traversal here.
if (changeHint & nsChangeHint_ReconstructFrame) {
ClearRestyleStateFromSubtree(aElement);
return;
}
// TODO(emilio): We could avoid some refcount traffic here, specially in the
// ServoComputedValues case, which uses atomic refcounting.
//
// Hold the old style context alive, because it could become a dangling
// pointer during the replacement. In practice it's not a huge deal (on
// GetNextContinuationWithSameStyle the pointer is not dereferenced, only
// compared), but better not playing with dangling pointers if not needed.
RefPtr<nsStyleContext> oldStyleContext =
styleFrame ? styleFrame->StyleContext() : nullptr;
UndisplayedNode* displayContentsNode = nullptr;
// FIXME(emilio, bug 1303605): This can be simpler for Servo.
// Note that we intentionally don't check for display: none content.
if (!oldStyleContext) {
displayContentsNode =
PresContext()->FrameConstructor()->GetDisplayContentsNodeFor(aElement);
if (displayContentsNode) {
oldStyleContext = displayContentsNode->mStyle;
}
}
RefPtr<ServoComputedValues> computedValues =
aStyleSet->ResolveServoStyle(aElement);
// Note that we rely in the fact that we don't cascade pseudo-element styles
// separately right now (that is, if a pseudo style changes, the normal style
// changes too).
//
// Otherwise we should probably encode that information somehow to avoid
// expensive checks in the common case.
//
// Also, we're going to need to check for pseudos of display: contents
// elements, though that is buggy right now even in non-stylo mode, see
// bug 1251799.
const bool recreateContext = oldStyleContext &&
oldStyleContext->StyleSource().AsServoComputedValues() != computedValues;
RefPtr<nsStyleContext> newContext = nullptr;
if (recreateContext) {
MOZ_ASSERT(styleFrame || displayContentsNode);
auto pseudo = aElement->GetPseudoElementType();
nsIAtom* pseudoTag = pseudo == CSSPseudoElementType::NotPseudo
? nullptr : nsCSSPseudoElements::GetPseudoAtom(pseudo);
newContext =
aStyleSet->GetContext(computedValues.forget(),
aParentContext,
pseudoTag,
pseudo,
aElement);
newContext->EnsureSameStructsCached(oldStyleContext);
// XXX This could not always work as expected: there are kinds of content
// with the first split and the last sharing style, but others not. We
// should handle those properly.
// XXXbz I think the UpdateStyleOfOwnedAnonBoxes call below handles _that_
// right, but not other cases where we happen to have different styles on
// different continuations... (e.g. first-line).
for (nsIFrame* f = styleFrame; f;
f = GetNextContinuationWithSameStyle(f, oldStyleContext)) {
f->SetStyleContext(newContext);
}
if (MOZ_UNLIKELY(displayContentsNode)) {
MOZ_ASSERT(!styleFrame);
displayContentsNode->mStyle = newContext;
}
if (styleFrame) {
styleFrame->UpdateStyleOfOwnedAnonBoxes(*aStyleSet, aChangeList, changeHint);
UpdateFramePseudoElementStyles(styleFrame, *aStyleSet, aChangeList);
}
// Some changes to animations don't affect the computed style and yet still
// require the layer to be updated. For example, pausing an animation via
// the Web Animations API won't affect an element's style but still
// requires to update the animation on the layer.
//
// We can sometimes reach this when the animated style is being removed.
// Since AddLayerChangesForAnimation checks if |styleFrame| has a transform
// style or not, we need to call it *after* setting |newContext| to
// |styleFrame| to ensure the animated transform has been removed first.
AddLayerChangesForAnimation(styleFrame, aElement, aChangeList);
}
const bool descendantsNeedFrames =
aElement->HasFlag(NODE_DESCENDANTS_NEED_FRAMES);
const bool traverseElementChildren =
aElement->HasDirtyDescendantsForServo() || descendantsNeedFrames;
const bool traverseTextChildren = recreateContext || descendantsNeedFrames;
if (traverseElementChildren || traverseTextChildren) {
nsStyleContext* upToDateContext =
recreateContext ? newContext : oldStyleContext;
StyleChildrenIterator it(aElement);
TextPostTraversalState textState(
*upToDateContext, *aStyleSet, displayContentsNode && recreateContext);
for (nsIContent* n = it.GetNextChild(); n; n = it.GetNextChild()) {
if (traverseElementChildren && n->IsElement()) {
ProcessPostTraversal(n->AsElement(), upToDateContext,
aStyleSet, aChangeList);
} else if (traverseTextChildren && n->IsNodeOfType(nsINode::eTEXT)) {
ProcessPostTraversalForText(n, aChangeList, textState);
}
}
}
aElement->UnsetHasDirtyDescendantsForServo();
aElement->UnsetFlags(NODE_DESCENDANTS_NEED_FRAMES);
}
void
ServoRestyleManager::ProcessPostTraversalForText(
nsIContent* aTextNode,
nsStyleChangeList& aChangeList,
TextPostTraversalState& aPostTraversalState)
{
// Handle lazy frame construction.
if (aTextNode->HasFlag(NODE_NEEDS_FRAME)) {
aChangeList.AppendChange(nullptr, aTextNode, nsChangeHint_ReconstructFrame);
return;
}
// Handle restyle.
nsIFrame* primaryFrame = aTextNode->GetPrimaryFrame();
if (primaryFrame) {
RefPtr<nsStyleContext> oldStyleContext = primaryFrame->StyleContext();
nsStyleContext& newContext = aPostTraversalState.ComputeStyle(aTextNode);
aPostTraversalState.ComputeHintIfNeeded(
aTextNode, primaryFrame, newContext, aChangeList);
for (nsIFrame* f = primaryFrame; f;
f = GetNextContinuationWithSameStyle(f, oldStyleContext)) {
f->SetStyleContext(&newContext);
}
}
}
void
ServoRestyleManager::ClearSnapshots()
{
for (auto iter = mSnapshots.Iter(); !iter.Done(); iter.Next()) {
iter.Key()->UnsetFlags(ELEMENT_HAS_SNAPSHOT | ELEMENT_HANDLED_SNAPSHOT);
iter.Remove();
}
}
ServoElementSnapshot&
ServoRestyleManager::SnapshotFor(Element* aElement)
{
MOZ_ASSERT(!mInStyleRefresh);
// NOTE(emilio): We can handle snapshots from a one-off restyle of those that
// we do to restyle stuff for reconstruction, for example.
//
// It seems to be the case that we always flush in between that happens and
// the next attribute change, so we can assert that we haven't handled the
// snapshot here yet. If this assertion didn't hold, we'd need to unset that
// flag from here too.
//
// Can't wait to make ProcessPendingRestyles the only entry-point for styling,
// so this becomes much easier to reason about. Today is not that day though.
MOZ_ASSERT(aElement->HasServoData());
MOZ_ASSERT(!aElement->HasFlag(ELEMENT_HANDLED_SNAPSHOT));
ServoElementSnapshot* snapshot = mSnapshots.LookupOrAdd(aElement, aElement);
aElement->SetFlags(ELEMENT_HAS_SNAPSHOT);
nsIPresShell* presShell = mPresContext->PresShell();
presShell->EnsureStyleFlush();
return *snapshot;
}
/* static */ nsIFrame*
ServoRestyleManager::FrameForPseudoElement(const nsIContent* aContent,
nsIAtom* aPseudoTagOrNull)
{
MOZ_ASSERT_IF(aPseudoTagOrNull, aContent->IsElement());
if (!aPseudoTagOrNull) {
return aContent->GetPrimaryFrame();
}
if (aPseudoTagOrNull == nsCSSPseudoElements::before) {
return nsLayoutUtils::GetBeforeFrame(aContent);
}
if (aPseudoTagOrNull == nsCSSPseudoElements::after) {
return nsLayoutUtils::GetAfterFrame(aContent);
}
MOZ_CRASH("Unkown pseudo-element given to "
"ServoRestyleManager::FrameForPseudoElement");
return nullptr;
}
void
ServoRestyleManager::DoProcessPendingRestyles(TraversalRestyleBehavior
aRestyleBehavior)
{
MOZ_ASSERT(PresContext()->Document(), "No document? Pshaw!");
MOZ_ASSERT(!nsContentUtils::IsSafeToRunScript(), "Missing a script blocker!");
MOZ_ASSERT(!mInStyleRefresh, "Reentrant call?");
if (MOZ_UNLIKELY(!PresContext()->PresShell()->DidInitialize())) {
// PresShell::FlushPendingNotifications doesn't early-return in the case
// where the PreShell hasn't yet been initialized (and therefore we haven't
// yet done the initial style traversal of the DOM tree). We should arguably
// fix up the callers and assert against this case, but we just detect and
// handle it for now.
return;
}
// Create a AnimationsWithDestroyedFrame during restyling process to
// stop animations and transitions on elements that have no frame at the end
// of the restyling process.
AnimationsWithDestroyedFrame animationsWithDestroyedFrame(this);
ServoStyleSet* styleSet = StyleSet();
nsIDocument* doc = PresContext()->Document();
bool animationOnly = aRestyleBehavior ==
TraversalRestyleBehavior::ForAnimationOnly;
// Ensure the refresh driver is active during traversal to avoid mutating
// mActiveTimer and mMostRecentRefresh time.
PresContext()->RefreshDriver()->MostRecentRefresh();
// Perform the Servo traversal, and the post-traversal if required. We do this
// in a loop because certain rare paths in the frame constructor (like
// uninstalling XBL bindings) can trigger additional style validations.
mInStyleRefresh = true;
if (mHaveNonAnimationRestyles && !animationOnly) {
++mAnimationGeneration;
}
TraversalRestyleBehavior restyleBehavior = mRestyleForCSSRuleChanges
? TraversalRestyleBehavior::ForCSSRuleChanges
: TraversalRestyleBehavior::Normal;
while (animationOnly ? styleSet->StyleDocumentForAnimationOnly()
: styleSet->StyleDocument(restyleBehavior)) {
if (!animationOnly) {
ClearSnapshots();
}
// Recreate style contexts, and queue up change hints (which also handle
// lazy frame construction).
nsStyleChangeList currentChanges(StyleBackendType::Servo);
DocumentStyleRootIterator iter(doc);
while (Element* root = iter.GetNextStyleRoot()) {
ProcessPostTraversal(root, nullptr, styleSet, currentChanges);
}
// Process the change hints.
//
// Unfortunately, the frame constructor can generate new change hints while
// processing existing ones. We redirect those into a secondary queue and
// iterate until there's nothing left.
ReentrantChangeList newChanges;
mReentrantChanges = &newChanges;
while (!currentChanges.IsEmpty()) {
ProcessRestyledFrames(currentChanges);
MOZ_ASSERT(currentChanges.IsEmpty());
for (ReentrantChange& change: newChanges) {
if (!(change.mHint & nsChangeHint_ReconstructFrame) &&
!change.mContent->GetPrimaryFrame()) {
// SVG Elements post change hints without ensuring that the primary
// frame will be there after that (see bug 1366142).
//
// Just ignore those, since we can't really process them.
continue;
}
currentChanges.AppendChange(change.mContent->GetPrimaryFrame(),
change.mContent, change.mHint);
}
newChanges.Clear();
}
mReentrantChanges = nullptr;
IncrementRestyleGeneration();
}
FlushOverflowChangedTracker();
if (!animationOnly) {
ClearSnapshots();
styleSet->AssertTreeIsClean();
mHaveNonAnimationRestyles = false;
}
mRestyleForCSSRuleChanges = false;
mInStyleRefresh = false;
// Note: We are in the scope of |animationsWithDestroyedFrame|, so
// |mAnimationsWithDestroyedFrame| is still valid.
MOZ_ASSERT(mAnimationsWithDestroyedFrame);
mAnimationsWithDestroyedFrame->StopAnimationsForElementsWithoutFrames();
}
void
ServoRestyleManager::ProcessPendingRestyles()
{
DoProcessPendingRestyles(TraversalRestyleBehavior::Normal);
}
void
ServoRestyleManager::UpdateOnlyAnimationStyles()
{
// Bug 1365855: We also need to implement this for SMIL.
bool doCSS = PresContext()->EffectCompositor()->HasPendingStyleUpdates();
if (!doCSS) {
return;
}
DoProcessPendingRestyles(TraversalRestyleBehavior::ForAnimationOnly);
}
void
ServoRestyleManager::RestyleForInsertOrChange(nsINode* aContainer,
nsIContent* aChild)
{
//
// XXXbholley: We need the Gecko logic here to correctly restyle for things
// like :empty and positional selectors (though we may not need to post
// restyle events as agressively as the Gecko path does).
//
// Bug 1297899 tracks this work.
//
}
void
ServoRestyleManager::RestyleForAppend(nsIContent* aContainer,
nsIContent* aFirstNewContent)
{
//
// XXXbholley: We need the Gecko logic here to correctly restyle for things
// like :empty and positional selectors (though we may not need to post
// restyle events as agressively as the Gecko path does).
//
// Bug 1297899 tracks this work.
//
}
void
ServoRestyleManager::ContentRemoved(nsINode* aContainer,
nsIContent* aOldChild,
nsIContent* aFollowingSibling)
{
NS_WARNING("stylo: ServoRestyleManager::ContentRemoved not implemented");
}
void
ServoRestyleManager::ContentStateChanged(nsIContent* aContent,
EventStates aChangedBits)
{
MOZ_ASSERT(!mInStyleRefresh);
if (!aContent->IsElement()) {
return;
}
Element* aElement = aContent->AsElement();
nsChangeHint changeHint;
nsRestyleHint restyleHint;
if (!aElement->HasServoData()) {
return;
}
// NOTE: restyleHint here is effectively always 0, since that's what
// ServoStyleSet::HasStateDependentStyle returns. Servo computes on
// ProcessPendingRestyles using the ElementSnapshot, but in theory could
// compute it sequentially easily.
//
// Determine what's the best way to do it, and how much work do we save
// processing the restyle hint early (i.e., computing the style hint here
// sequentially, potentially saving the snapshot), vs lazily (snapshot
// approach).
//
// If we take the sequential approach we need to specialize Servo's restyle
// hints system a bit more, and mesure whether we save something storing the
// restyle hint in the table and deferring the dirtiness setting until
// ProcessPendingRestyles (that's a requirement if we store snapshots though),
// vs processing the restyle hint in-place, dirtying the nodes on
// PostRestyleEvent.
//
// If we definitely take the snapshot approach, we should take rid of
// HasStateDependentStyle, etc (though right now they're no-ops).
ContentStateChangedInternal(aElement, aChangedBits, &changeHint,
&restyleHint);
ServoElementSnapshot& snapshot = SnapshotFor(aElement);
EventStates previousState = aElement->StyleState() ^ aChangedBits;
snapshot.AddState(previousState);
if (Element* parent = aElement->GetFlattenedTreeParentElementForStyle()) {
parent->NoteDirtyDescendantsForServo();
}
PostRestyleEvent(aElement, restyleHint, changeHint);
}
void
ServoRestyleManager::AttributeWillChange(Element* aElement,
int32_t aNameSpaceID,
nsIAtom* aAttribute, int32_t aModType,
const nsAttrValue* aNewValue)
{
MOZ_ASSERT(!mInStyleRefresh);
if (!aElement->HasServoData()) {
return;
}
ServoElementSnapshot& snapshot = SnapshotFor(aElement);
snapshot.AddAttrs(aElement);
if (Element* parent = aElement->GetFlattenedTreeParentElementForStyle()) {
parent->NoteDirtyDescendantsForServo();
}
}
void
ServoRestyleManager::AttributeChanged(Element* aElement, int32_t aNameSpaceID,
nsIAtom* aAttribute, int32_t aModType,
const nsAttrValue* aOldValue)
{
MOZ_ASSERT(!mInStyleRefresh);
MOZ_ASSERT_IF(mSnapshots.Get(aElement), mSnapshots.Get(aElement)->HasAttrs());
nsIFrame* primaryFrame = aElement->GetPrimaryFrame();
if (primaryFrame) {
primaryFrame->AttributeChanged(aNameSpaceID, aAttribute, aModType);
}
nsChangeHint hint = aElement->GetAttributeChangeHint(aAttribute, aModType);
if (hint) {
PostRestyleEvent(aElement, nsRestyleHint(0), hint);
}
if (aAttribute == nsGkAtoms::style) {
PostRestyleEvent(aElement, eRestyle_StyleAttribute, nsChangeHint(0));
}
// <td> is affected by the cellpadding on its ancestor table,
// so we should restyle the whole subtree
if (aAttribute == nsGkAtoms::cellpadding && aElement->IsHTMLElement(nsGkAtoms::table)) {
PostRestyleEvent(aElement, eRestyle_Subtree, nsChangeHint(0));
}
if (aElement->IsAttributeMapped(aAttribute)) {
Servo_NoteExplicitHints(aElement, eRestyle_Self, nsChangeHint(0));
}
}
nsresult
ServoRestyleManager::ReparentStyleContext(nsIFrame* aFrame)
{
NS_WARNING("stylo: ServoRestyleManager::ReparentStyleContext not implemented");
return NS_OK;
}
} // namespace mozilla