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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "mozilla/RestyleManager.h"
#include "mozilla/AnimationUtils.h"
#include "mozilla/Assertions.h"
#include "mozilla/ComputedStyle.h"
#include "mozilla/ComputedStyleInlines.h"
#include "mozilla/DocumentStyleRootIterator.h"
#include "mozilla/EffectSet.h"
#include "mozilla/GeckoBindings.h"
#include "mozilla/LayerAnimationInfo.h"
#include "mozilla/layers/AnimationInfo.h"
#include "mozilla/layout/ScrollAnchorContainer.h"
#include "mozilla/PresShell.h"
#include "mozilla/PresShellInlines.h"
#include "mozilla/ProfilerLabels.h"
#include "mozilla/ServoBindings.h"
#include "mozilla/ServoStyleSetInlines.h"
#include "mozilla/StaticPrefs_layout.h"
#include "mozilla/SVGIntegrationUtils.h"
#include "mozilla/SVGObserverUtils.h"
#include "mozilla/SVGTextFrame.h"
#include "mozilla/SVGUtils.h"
#include "mozilla/Unused.h"
#include "mozilla/ViewportFrame.h"
#include "mozilla/IntegerRange.h"
#include "mozilla/dom/ChildIterator.h"
#include "mozilla/dom/DocumentInlines.h"
#include "mozilla/dom/ElementInlines.h"
#include "mozilla/dom/HTMLBodyElement.h"
#include "mozilla/dom/HTMLInputElement.h"
#include "ScrollSnap.h"
#include "nsAnimationManager.h"
#include "nsBlockFrame.h"
#include "nsIScrollableFrame.h"
#include "nsContentUtils.h"
#include "nsCSSFrameConstructor.h"
#include "nsCSSRendering.h"
#include "nsDocShell.h"
#include "nsIFrame.h"
#include "nsIFrameInlines.h"
#include "nsImageFrame.h"
#include "nsPlaceholderFrame.h"
#include "nsPrintfCString.h"
#include "nsRefreshDriver.h"
#include "nsStyleChangeList.h"
#include "nsStyleUtil.h"
#include "nsTransitionManager.h"
#include "StickyScrollContainer.h"
#include "ActiveLayerTracker.h"
#ifdef ACCESSIBILITY
# include "nsAccessibilityService.h"
#endif
using mozilla::layers::AnimationInfo;
using mozilla::layout::ScrollAnchorContainer;
using namespace mozilla::dom;
using namespace mozilla::layers;
namespace mozilla {
RestyleManager::RestyleManager(nsPresContext* aPresContext)
: mPresContext(aPresContext),
mRestyleGeneration(1),
mUndisplayedRestyleGeneration(1),
mInStyleRefresh(false),
mAnimationGeneration(0) {
MOZ_ASSERT(mPresContext);
}
void RestyleManager::ContentInserted(nsIContent* aChild) {
MOZ_ASSERT(aChild->GetParentNode());
if (aChild->IsElement()) {
StyleSet()->MaybeInvalidateForElementInsertion(*aChild->AsElement());
}
RestyleForInsertOrChange(aChild);
}
void RestyleManager::ContentAppended(nsIContent* aFirstNewContent) {
auto* container = aFirstNewContent->GetParentNode();
MOZ_ASSERT(container);
#ifdef DEBUG
{
for (nsIContent* cur = aFirstNewContent; cur; cur = cur->GetNextSibling()) {
NS_ASSERTION(!cur->IsRootOfNativeAnonymousSubtree(),
"anonymous nodes should not be in child lists");
}
}
#endif
StyleSet()->MaybeInvalidateForElementAppend(*aFirstNewContent);
const auto selectorFlags = container->GetSelectorFlags() &
NodeSelectorFlags::AllSimpleRestyleFlagsForAppend;
if (!selectorFlags) {
return;
}
// The container cannot be a document.
MOZ_ASSERT(container->IsElement() || container->IsShadowRoot());
if (selectorFlags & NodeSelectorFlags::HasEmptySelector) {
// see whether we need to restyle the container
bool wasEmpty = true; // :empty or :-moz-only-whitespace
for (nsIContent* cur = container->GetFirstChild(); cur != aFirstNewContent;
cur = cur->GetNextSibling()) {
// We don't know whether we're testing :empty or :-moz-only-whitespace,
// so be conservative and assume :-moz-only-whitespace (i.e., make
// IsSignificantChild less likely to be true, and thus make us more
// likely to restyle).
if (nsStyleUtil::IsSignificantChild(cur, false)) {
wasEmpty = false;
break;
}
}
if (wasEmpty && container->IsElement()) {
RestyleForEmptyChange(container->AsElement());
return;
}
}
if (selectorFlags & NodeSelectorFlags::HasSlowSelector) {
if (container->IsElement()) {
auto* containerElement = container->AsElement();
PostRestyleEvent(containerElement, RestyleHint::RestyleSubtree(),
nsChangeHint(0));
if (selectorFlags & NodeSelectorFlags::HasSlowSelectorNthAll) {
StyleSet()->MaybeInvalidateRelativeSelectorForNthDependencyFromSibling(
containerElement->GetFirstElementChild());
}
} else {
RestylePreviousSiblings(aFirstNewContent);
RestyleSiblingsStartingWith(aFirstNewContent);
}
// Restyling the container is the most we can do here, so we're done.
return;
}
if (selectorFlags & NodeSelectorFlags::HasEdgeChildSelector) {
// restyle the last element child before this node
for (nsIContent* cur = aFirstNewContent->GetPreviousSibling(); cur;
cur = cur->GetPreviousSibling()) {
if (cur->IsElement()) {
auto* element = cur->AsElement();
PostRestyleEvent(element, RestyleHint::RestyleSubtree(),
nsChangeHint(0));
StyleSet()->MaybeInvalidateRelativeSelectorForNthEdgeDependency(
*element);
break;
}
}
}
}
void RestyleManager::RestylePreviousSiblings(nsIContent* aStartingSibling) {
for (nsIContent* sibling = aStartingSibling; sibling;
sibling = sibling->GetPreviousSibling()) {
if (auto* element = Element::FromNode(sibling)) {
PostRestyleEvent(element, RestyleHint::RestyleSubtree(), nsChangeHint(0));
}
}
}
void RestyleManager::RestyleSiblingsStartingWith(nsIContent* aStartingSibling) {
for (nsIContent* sibling = aStartingSibling; sibling;
sibling = sibling->GetNextSibling()) {
if (auto* element = Element::FromNode(sibling)) {
PostRestyleEvent(element, RestyleHint::RestyleSubtree(), nsChangeHint(0));
}
}
}
void RestyleManager::RestyleForEmptyChange(Element* aContainer) {
PostRestyleEvent(aContainer, RestyleHint::RestyleSubtree(), nsChangeHint(0));
StyleSet()->MaybeInvalidateRelativeSelectorForEmptyDependency(*aContainer);
// In some cases (:empty + E, :empty ~ E), a change in the content of
// an element requires restyling its parent's siblings.
nsIContent* grandparent = aContainer->GetParent();
if (!grandparent || !(grandparent->GetSelectorFlags() &
NodeSelectorFlags::HasSlowSelectorLaterSiblings)) {
return;
}
RestyleSiblingsStartingWith(aContainer->GetNextSibling());
}
void RestyleManager::MaybeRestyleForEdgeChildChange(nsINode* aContainer,
nsIContent* aChangedChild) {
MOZ_ASSERT(aContainer->GetSelectorFlags() &
NodeSelectorFlags::HasEdgeChildSelector);
MOZ_ASSERT(aChangedChild->GetParent() == aContainer);
// restyle the previously-first element child if it is after this node
bool passedChild = false;
for (nsIContent* content = aContainer->GetFirstChild(); content;
content = content->GetNextSibling()) {
if (content == aChangedChild) {
passedChild = true;
continue;
}
if (content->IsElement()) {
if (passedChild) {
auto* element = content->AsElement();
PostRestyleEvent(element, RestyleHint::RestyleSubtree(),
nsChangeHint(0));
StyleSet()->MaybeInvalidateRelativeSelectorForNthEdgeDependency(
*element);
}
break;
}
}
// restyle the previously-last element child if it is before this node
passedChild = false;
for (nsIContent* content = aContainer->GetLastChild(); content;
content = content->GetPreviousSibling()) {
if (content == aChangedChild) {
passedChild = true;
continue;
}
if (content->IsElement()) {
if (passedChild) {
auto* element = content->AsElement();
PostRestyleEvent(element, RestyleHint::RestyleSubtree(),
nsChangeHint(0));
StyleSet()->MaybeInvalidateRelativeSelectorForNthEdgeDependency(
*element);
}
break;
}
}
}
template <typename CharT>
bool WhitespaceOnly(const CharT* aBuffer, size_t aUpTo) {
for (auto index : IntegerRange(aUpTo)) {
if (!dom::IsSpaceCharacter(aBuffer[index])) {
return false;
}
}
return true;
}
template <typename CharT>
bool WhitespaceOnlyChangedOnAppend(const CharT* aBuffer, size_t aOldLength,
size_t aNewLength) {
MOZ_ASSERT(aOldLength <= aNewLength);
if (!WhitespaceOnly(aBuffer, aOldLength)) {
// The old text was already not whitespace-only.
return false;
}
return !WhitespaceOnly(aBuffer + aOldLength, aNewLength - aOldLength);
}
static bool HasAnySignificantSibling(Element* aContainer, nsIContent* aChild) {
MOZ_ASSERT(aChild->GetParent() == aContainer);
for (nsIContent* child = aContainer->GetFirstChild(); child;
child = child->GetNextSibling()) {
if (child == aChild) {
continue;
}
// We don't know whether we're testing :empty or :-moz-only-whitespace,
// so be conservative and assume :-moz-only-whitespace (i.e., make
// IsSignificantChild less likely to be true, and thus make us more
// likely to restyle).
if (nsStyleUtil::IsSignificantChild(child, false)) {
return true;
}
}
return false;
}
void RestyleManager::CharacterDataChanged(
nsIContent* aContent, const CharacterDataChangeInfo& aInfo) {
nsINode* parent = aContent->GetParentNode();
MOZ_ASSERT(parent, "How were we notified of a stray node?");
const auto slowSelectorFlags =
parent->GetSelectorFlags() & NodeSelectorFlags::AllSimpleRestyleFlags;
if (!(slowSelectorFlags & (NodeSelectorFlags::HasEmptySelector |
NodeSelectorFlags::HasEdgeChildSelector))) {
// Nothing to do, no other slow selector can change as a result of this.
return;
}
if (!aContent->IsText()) {
// Doesn't matter to styling (could be a processing instruction or a
// comment), it can't change whether any selectors match or don't.
return;
}
if (MOZ_UNLIKELY(!parent->IsElement())) {
MOZ_ASSERT(parent->IsShadowRoot());
return;
}
if (MOZ_UNLIKELY(aContent->IsRootOfNativeAnonymousSubtree())) {
// This is an anonymous node and thus isn't in child lists, so isn't taken
// into account for selector matching the relevant selectors here.
return;
}
// Handle appends specially since they're common and we can know both the old
// and the new text exactly.
//
// TODO(emilio): This could be made much more general if :-moz-only-whitespace
// / :-moz-first-node and :-moz-last-node didn't exist. In that case we only
// need to know whether we went from empty to non-empty, and that's trivial to
// know, with CharacterDataChangeInfo...
if (!aInfo.mAppend) {
// FIXME(emilio): This restyles unnecessarily if the text node is the only
// child of the parent element. Fortunately, it's uncommon to have such
// nodes and this not being an append.
//
RestyleForInsertOrChange(aContent);
return;
}
const nsTextFragment* text = &aContent->AsText()->TextFragment();
const size_t oldLength = aInfo.mChangeStart;
const size_t newLength = text->GetLength();
const bool emptyChanged = !oldLength && newLength;
const bool whitespaceOnlyChanged =
text->Is2b()
? WhitespaceOnlyChangedOnAppend(text->Get2b(), oldLength, newLength)
: WhitespaceOnlyChangedOnAppend(text->Get1b(), oldLength, newLength);
if (!emptyChanged && !whitespaceOnlyChanged) {
return;
}
if (slowSelectorFlags & NodeSelectorFlags::HasEmptySelector) {
if (!HasAnySignificantSibling(parent->AsElement(), aContent)) {
// We used to be empty, restyle the parent.
RestyleForEmptyChange(parent->AsElement());
return;
}
}
if (slowSelectorFlags & NodeSelectorFlags::HasEdgeChildSelector) {
MaybeRestyleForEdgeChildChange(parent, aContent);
}
}
// Restyling for a ContentInserted or CharacterDataChanged notification.
// This could be used for ContentRemoved as well if we got the
// notification before the removal happened (and sometimes
// CharacterDataChanged is more like a removal than an addition).
// The comments are written and variables are named in terms of it being
// a ContentInserted notification.
void RestyleManager::RestyleForInsertOrChange(nsIContent* aChild) {
nsINode* container = aChild->GetParentNode();
MOZ_ASSERT(container);
const auto selectorFlags =
container->GetSelectorFlags() & NodeSelectorFlags::AllSimpleRestyleFlags;
if (!selectorFlags) {
return;
}
NS_ASSERTION(!aChild->IsRootOfNativeAnonymousSubtree(),
"anonymous nodes should not be in child lists");
// The container cannot be a document.
MOZ_ASSERT(container->IsElement() || container->IsShadowRoot());
if (selectorFlags & NodeSelectorFlags::HasEmptySelector &&
container->IsElement()) {
// See whether we need to restyle the container due to :empty /
// :-moz-only-whitespace.
const bool wasEmpty =
!HasAnySignificantSibling(container->AsElement(), aChild);
if (wasEmpty) {
// FIXME(emilio): When coming from CharacterDataChanged this can restyle
// unnecessarily. Also can restyle unnecessarily if aChild is not
// significant anyway, though that's more unlikely.
RestyleForEmptyChange(container->AsElement());
return;
}
}
if (selectorFlags & NodeSelectorFlags::HasSlowSelector) {
if (container->IsElement()) {
auto* containerElement = container->AsElement();
PostRestyleEvent(containerElement, RestyleHint::RestyleSubtree(),
nsChangeHint(0));
if (selectorFlags & NodeSelectorFlags::HasSlowSelectorNthAll) {
StyleSet()->MaybeInvalidateRelativeSelectorForNthDependencyFromSibling(
containerElement->GetFirstElementChild());
}
} else {
RestylePreviousSiblings(aChild);
RestyleSiblingsStartingWith(aChild);
}
// Restyling the container is the most we can do here, so we're done.
return;
}
if (selectorFlags & NodeSelectorFlags::HasSlowSelectorLaterSiblings) {
// Restyle all later siblings.
RestyleSiblingsStartingWith(aChild->GetNextSibling());
if (selectorFlags & NodeSelectorFlags::HasSlowSelectorNthAll) {
StyleSet()->MaybeInvalidateRelativeSelectorForNthDependencyFromSibling(
aChild->GetNextElementSibling());
}
}
if (selectorFlags & NodeSelectorFlags::HasEdgeChildSelector) {
MaybeRestyleForEdgeChildChange(container, aChild);
}
}
void RestyleManager::ContentRemoved(nsIContent* aOldChild,
nsIContent* aFollowingSibling) {
auto* container = aOldChild->GetParentNode();
MOZ_ASSERT(container);
// Computed style data isn't useful for detached nodes, and we'll need to
// recompute it anyway if we ever insert the nodes back into a document.
if (auto* element = Element::FromNode(aOldChild)) {
RestyleManager::ClearServoDataFromSubtree(element);
// If this element is undisplayed or may have undisplayed descendants, we
// need to invalidate the cache, since there's the unlikely event of those
// elements getting destroyed and their addresses reused in a way that we
// look up the cache with their address for a different element before it's
// invalidated.
IncrementUndisplayedRestyleGeneration();
}
if (aOldChild->IsElement()) {
StyleSet()->MaybeInvalidateForElementRemove(*aOldChild->AsElement(),
aFollowingSibling);
}
const auto selectorFlags =
container->GetSelectorFlags() & NodeSelectorFlags::AllSimpleRestyleFlags;
if (!selectorFlags) {
return;
}
if (aOldChild->IsRootOfNativeAnonymousSubtree()) {
// This should be an assert, but this is called incorrectly in
// HTMLEditor::DeleteRefToAnonymousNode and the assertions were clogging
// up the logs. Make it an assert again when that's fixed.
MOZ_ASSERT(aOldChild->GetProperty(nsGkAtoms::restylableAnonymousNode),
}
// The container cannot be a document.
MOZ_ASSERT(container->IsElement() || container->IsShadowRoot());
if (selectorFlags & NodeSelectorFlags::HasEmptySelector &&
container->IsElement()) {
// see whether we need to restyle the container
bool isEmpty = true; // :empty or :-moz-only-whitespace
for (nsIContent* child = container->GetFirstChild(); child;
child = child->GetNextSibling()) {
// We don't know whether we're testing :empty or :-moz-only-whitespace,
// so be conservative and assume :-moz-only-whitespace (i.e., make
// IsSignificantChild less likely to be true, and thus make us more
// likely to restyle).
if (nsStyleUtil::IsSignificantChild(child, false)) {
isEmpty = false;
break;
}
}
if (isEmpty && container->IsElement()) {
RestyleForEmptyChange(container->AsElement());
return;
}
}
if (selectorFlags & NodeSelectorFlags::HasSlowSelector) {
if (container->IsElement()) {
auto* containerElement = container->AsElement();
PostRestyleEvent(containerElement, RestyleHint::RestyleSubtree(),
nsChangeHint(0));
if (selectorFlags & NodeSelectorFlags::HasSlowSelectorNthAll) {
StyleSet()->MaybeInvalidateRelativeSelectorForNthDependencyFromSibling(
containerElement->GetFirstElementChild());
}
} else {
RestylePreviousSiblings(aOldChild);
RestyleSiblingsStartingWith(aOldChild);
}
// Restyling the container is the most we can do here, so we're done.
return;
}
if (selectorFlags & NodeSelectorFlags::HasSlowSelectorLaterSiblings) {
// Restyle all later siblings.
RestyleSiblingsStartingWith(aFollowingSibling);
if (selectorFlags & NodeSelectorFlags::HasSlowSelectorNthAll) {
Element* nextSibling =
aFollowingSibling ? aFollowingSibling->IsElement()
? aFollowingSibling->AsElement()
: aFollowingSibling->GetNextElementSibling()
: nullptr;
StyleSet()->MaybeInvalidateRelativeSelectorForNthDependencyFromSibling(
nextSibling);
}
}
if (selectorFlags & NodeSelectorFlags::HasEdgeChildSelector) {
// restyle the now-first element child if it was after aOldChild
bool reachedFollowingSibling = false;
for (nsIContent* content = container->GetFirstChild(); content;
content = content->GetNextSibling()) {
if (content == aFollowingSibling) {
reachedFollowingSibling = true;
// do NOT continue here; we might want to restyle this node
}
if (content->IsElement()) {
if (reachedFollowingSibling) {
auto* element = content->AsElement();
PostRestyleEvent(element, RestyleHint::RestyleSubtree(),
nsChangeHint(0));
StyleSet()->MaybeInvalidateRelativeSelectorForNthEdgeDependency(
*element);
}
break;
}
}
// restyle the now-last element child if it was before aOldChild
reachedFollowingSibling = (aFollowingSibling == nullptr);
for (nsIContent* content = container->GetLastChild(); content;
content = content->GetPreviousSibling()) {
if (content->IsElement()) {
if (reachedFollowingSibling) {
auto* element = content->AsElement();
PostRestyleEvent(element, RestyleHint::RestyleSubtree(),
nsChangeHint(0));
StyleSet()->MaybeInvalidateRelativeSelectorForNthEdgeDependency(
*element);
}
break;
}
if (content == aFollowingSibling) {
reachedFollowingSibling = true;
}
}
}
}
static bool StateChangeMayAffectFrame(const Element& aElement,
const nsIFrame& aFrame,
ElementState aStates) {
const bool brokenChanged = aStates.HasState(ElementState::BROKEN);
if (!brokenChanged) {
return false;
}
if (aFrame.IsGeneratedContentFrame()) {
// If it's other generated content, ignore state changes on it.
return aElement.IsHTMLElement(nsGkAtoms::mozgeneratedcontentimage);
}
if (aElement.IsAnyOfHTMLElements(nsGkAtoms::object, nsGkAtoms::embed)) {
// Broken affects object fallback behavior.
return true;
}
const bool mightChange = [&] {
if (aElement.IsHTMLElement(nsGkAtoms::img)) {
return true;
}
const auto* input = HTMLInputElement::FromNode(aElement);
return input && input->ControlType() == FormControlType::InputImage;
}();
if (!mightChange) {
return false;
}
const bool needsImageFrame =
nsImageFrame::ImageFrameTypeFor(aElement, *aFrame.Style()) !=
nsImageFrame::ImageFrameType::None;
return needsImageFrame != aFrame.IsImageFrameOrSubclass();
}
static bool RepaintForAppearance(nsIFrame& aFrame, const Element& aElement,
ElementState aStateMask) {
if (aStateMask.HasAtLeastOneOfStates(ElementState::HOVER |
ElementState::ACTIVE) &&
aElement.IsAnyOfXULElements(nsGkAtoms::checkbox, nsGkAtoms::radio)) {
// The checkbox inside these elements inherit hover state and so on, see
// nsNativeTheme::GetContentState.
// FIXME(emilio): Would be nice to not have these hard-coded.
return true;
}
auto appearance = aFrame.StyleDisplay()->EffectiveAppearance();
if (appearance == StyleAppearance::None) {
return false;
}
nsPresContext* pc = aFrame.PresContext();
nsITheme* theme = pc->Theme();
if (!theme->ThemeSupportsWidget(pc, &aFrame, appearance)) {
return false;
}
bool repaint = false;
theme->WidgetStateChanged(&aFrame, appearance, nullptr, &repaint, nullptr);
return repaint;
}
/**
* Calculates the change hint and the restyle hint for a given content state
* change.
*/
static nsChangeHint ChangeForContentStateChange(const Element& aElement,
ElementState aStateMask) {
auto changeHint = nsChangeHint(0);
// Any change to a content state that affects which frames we construct
// must lead to a frame reconstruct here if we already have a frame.
// Note that we never decide through non-CSS means to not create frames
// based on content states, so if we already don't have a frame we don't
// need to force a reframe -- if it's needed, the HasStateDependentStyle
// call will handle things.
if (nsIFrame* primaryFrame = aElement.GetPrimaryFrame()) {
if (StateChangeMayAffectFrame(aElement, *primaryFrame, aStateMask)) {
return nsChangeHint_ReconstructFrame;
}
if (RepaintForAppearance(*primaryFrame, aElement, aStateMask)) {
changeHint |= nsChangeHint_RepaintFrame;
}
primaryFrame->ElementStateChanged(aStateMask);
}
if (aStateMask.HasState(ElementState::VISITED)) {
// Exposing information to the page about whether the link is
// visited or not isn't really something we can worry about here.
// FIXME: We could probably do this a bit better.
changeHint |= nsChangeHint_RepaintFrame;
}
// This changes the applicable text-transform in the editor root.
if (aStateMask.HasState(ElementState::REVEALED)) {
// This is the same change hint as tweaking text-transform.
changeHint |= NS_STYLE_HINT_REFLOW;
}
return changeHint;
}
#ifdef DEBUG
/* static */
nsCString RestyleManager::ChangeHintToString(nsChangeHint aHint) {
nsCString result;
bool any = false;
const char* names[] = {"RepaintFrame",
"NeedReflow",
"ClearAncestorIntrinsics",
"ClearDescendantIntrinsics",
"NeedDirtyReflow",
"UpdateCursor",
"UpdateEffects",
"UpdateOpacityLayer",
"UpdateTransformLayer",
"ReconstructFrame",
"UpdateOverflow",
"UpdateSubtreeOverflow",
"UpdatePostTransformOverflow",
"UpdateParentOverflow",
"ChildrenOnlyTransform",
"RecomputePosition",
"UpdateContainingBlock",
"BorderStyleNoneChange",
"SchedulePaint",
"NeutralChange",
"InvalidateRenderingObservers",
"ReflowChangesSizeOrPosition",
"UpdateComputedBSize",
"UpdateUsesOpacity",
"UpdateBackgroundPosition",
"AddOrRemoveTransform",
"ScrollbarChange",
"UpdateTableCellSpans",
"VisibilityChange"};
static_assert(nsChangeHint_AllHints ==
static_cast<uint32_t>((1ull << ArrayLength(names)) - 1),
"Name list doesn't match change hints.");
uint32_t hint =
aHint & static_cast<uint32_t>((1ull << ArrayLength(names)) - 1);
uint32_t rest =
aHint & ~static_cast<uint32_t>((1ull << ArrayLength(names)) - 1);
if ((hint & NS_STYLE_HINT_REFLOW) == NS_STYLE_HINT_REFLOW) {
result.AppendLiteral("NS_STYLE_HINT_REFLOW");
hint = hint & ~NS_STYLE_HINT_REFLOW;
any = true;
} else if ((hint & nsChangeHint_AllReflowHints) ==
nsChangeHint_AllReflowHints) {
result.AppendLiteral("nsChangeHint_AllReflowHints");
hint = hint & ~nsChangeHint_AllReflowHints;
any = true;
} else if ((hint & NS_STYLE_HINT_VISUAL) == NS_STYLE_HINT_VISUAL) {
result.AppendLiteral("NS_STYLE_HINT_VISUAL");
hint = hint & ~NS_STYLE_HINT_VISUAL;
any = true;
}
for (uint32_t i = 0; i < ArrayLength(names); i++) {
if (hint & (1u << i)) {
if (any) {
result.AppendLiteral(" | ");
}
result.AppendPrintf("nsChangeHint_%s", names[i]);
any = true;
}
}
if (rest) {
if (any) {
result.AppendLiteral(" | ");
}
result.AppendPrintf("0x%0x", rest);
} else {
if (!any) {
result.AppendLiteral("nsChangeHint(0)");
}
}
return result;
}
#endif
/**
* Frame construction helpers follow.
*/
#ifdef DEBUG
static bool gInApplyRenderingChangeToTree = false;
#endif
/**
* Sync views on the frame and all of it's descendants (following placeholders).
* The change hint should be some combination of nsChangeHint_RepaintFrame,
* nsChangeHint_UpdateOpacityLayer and nsChangeHint_SchedulePaint, nothing else.
*/
static void SyncViewsAndInvalidateDescendants(nsIFrame*, nsChangeHint);
static void StyleChangeReflow(nsIFrame* aFrame, nsChangeHint aHint);
/**
* This helper function is used to find the correct SVG frame to target when we
* encounter nsChangeHint_ChildrenOnlyTransform; needed since sometimes we end
* up handling that hint while processing hints for one of the SVG frame's
* ancestor frames.
*
* The reason that we sometimes end up trying to process the hint for an
* ancestor of the SVG frame that the hint is intended for is due to the way we
* process restyle events. ApplyRenderingChangeToTree adjusts the frame from
* the restyled element's principle frame to one of its ancestor frames based
* on what nsCSSRendering::FindBackground returns, since the background style
* may have been propagated up to an ancestor frame. Processing hints using an
* ancestor frame is fine in general, but nsChangeHint_ChildrenOnlyTransform is
* a special case since it is intended to update a specific frame.
*/
static nsIFrame* GetFrameForChildrenOnlyTransformHint(nsIFrame* aFrame) {
if (aFrame->IsViewportFrame()) {
// This happens if the root-<svg> is fixed positioned, in which case we
// can't use aFrame->GetContent() to find the primary frame, since
// GetContent() returns nullptr for ViewportFrame.
aFrame = aFrame->PrincipalChildList().FirstChild();
}
// For an nsHTMLScrollFrame, this will get the SVG frame that has the
// children-only transforms:
aFrame = aFrame->GetContent()->GetPrimaryFrame();
if (aFrame->IsSVGOuterSVGFrame()) {
aFrame = aFrame->PrincipalChildList().FirstChild();
MOZ_ASSERT(aFrame->IsSVGOuterSVGAnonChildFrame(),
"Where is the SVGOuterSVGFrame's anon child??");
}
MOZ_ASSERT(aFrame->IsSVGContainerFrame(),
"Children-only transforms only expected on SVG frames");
return aFrame;
}
// This function tries to optimize a position style change by either
// moving aFrame or ignoring the style change when it's safe to do so.
// It returns true when that succeeds, otherwise it posts a reflow request
// and returns false.
static bool RecomputePosition(nsIFrame* aFrame) {
// It's pointless to move around frames that have never been reflowed or
// are dirty (i.e. they will be reflowed), or aren't affected by position
// styles.
if (aFrame->HasAnyStateBits(NS_FRAME_FIRST_REFLOW | NS_FRAME_IS_DIRTY |
NS_FRAME_SVG_LAYOUT)) {
return true;
}
// Don't process position changes on table frames, since we already handle
// the dynamic position change on the table wrapper frame, and the
// reflow-based fallback code path also ignores positions on inner table
// frames.
if (aFrame->IsTableFrame()) {
return true;
}
const nsStyleDisplay* display = aFrame->StyleDisplay();
// Changes to the offsets of a non-positioned element can safely be ignored.
if (display->mPosition == StylePositionProperty::Static) {
return true;
}
// Don't process position changes on frames which have views or the ones which
// have a view somewhere in their descendants, because the corresponding view
// needs to be repositioned properly as well.
if (aFrame->HasView() ||
aFrame->HasAnyStateBits(NS_FRAME_HAS_CHILD_WITH_VIEW)) {
return false;
}
if (aFrame->HasAnyStateBits(NS_FRAME_OUT_OF_FLOW)) {
// If the frame has an intrinsic block-size, we resolve its 'auto' margins
// after doing layout, since we need to know the frame's block size. See
// nsAbsoluteContainingBlock::ResolveAutoMarginsAfterLayout().
//
// Since the size of the frame doesn't change, we could modify the below
// computation to compute the margin correctly without doing a full reflow,
// however we decided to try doing a full reflow for now.
if (aFrame->HasIntrinsicKeywordForBSize()) {
WritingMode wm = aFrame->GetWritingMode();
const auto* styleMargin = aFrame->StyleMargin();
if (styleMargin->HasBlockAxisAuto(wm)) {
return false;
}
}
// Flexbox and Grid layout supports CSS Align and the optimizations below
// don't support that yet.
nsIFrame* ph = aFrame->GetPlaceholderFrame();
if (ph && ph->HasAnyStateBits(PLACEHOLDER_STATICPOS_NEEDS_CSSALIGN)) {
return false;
}
}
// If we need to reposition any descendant that depends on our static
// position, then we also can't take the optimized path.
//
// TODO(emilio): It may be worth trying to find them and try to call
// RecomputePosition on them too instead of disabling the optimization...
if (aFrame->DescendantMayDependOnItsStaticPosition()) {
return false;
}
aFrame->SchedulePaint();
auto postPendingScrollAnchorOrResnap = [](nsIFrame* frame) {
if (frame->IsInScrollAnchorChain()) {
ScrollAnchorContainer* container = ScrollAnchorContainer::FindFor(frame);
frame->PresShell()->PostPendingScrollAnchorAdjustment(container);
}
// We need to trigger re-snapping to this content if we snapped to the
// content on the last scroll operation.
ScrollSnapUtils::PostPendingResnapIfNeededFor(frame);
};
// For relative positioning, we can simply update the frame rect
if (display->IsRelativelyOrStickyPositionedStyle()) {
if (aFrame->IsGridItem()) {
// A grid item's CB is its grid area, not the parent frame content area
// as is assumed below.
return false;
}
// Move the frame
if (display->mPosition == StylePositionProperty::Sticky) {
// Update sticky positioning for an entire element at once, starting with
// the first continuation or ib-split sibling.
// It's rare that the frame we already have isn't already the first
// continuation or ib-split sibling, but it can happen when styles differ
// across continuations such as ::first-line or ::first-letter, and in
// those cases we will generally (but maybe not always) do the work twice.
nsIFrame* firstContinuation =
nsLayoutUtils::FirstContinuationOrIBSplitSibling(aFrame);
StickyScrollContainer::ComputeStickyOffsets(firstContinuation);
StickyScrollContainer* ssc =
StickyScrollContainer::GetStickyScrollContainerForFrame(
firstContinuation);
if (ssc) {
ssc->PositionContinuations(firstContinuation);
}
} else {
MOZ_ASSERT(display->IsRelativelyPositionedStyle(),
"Unexpected type of positioning");
for (nsIFrame* cont = aFrame; cont;
cont = nsLayoutUtils::GetNextContinuationOrIBSplitSibling(cont)) {
nsIFrame* cb = cont->GetContainingBlock();
WritingMode wm = cb->GetWritingMode();
const LogicalSize cbSize = cb->ContentSize();
const LogicalMargin newLogicalOffsets =
ReflowInput::ComputeRelativeOffsets(wm, cont, cbSize);
const nsMargin newOffsets = newLogicalOffsets.GetPhysicalMargin(wm);
// ReflowInput::ApplyRelativePositioning would work here, but
// since we've already checked mPosition and aren't changing the frame's
// normal position, go ahead and add the offsets directly.
// First, we need to ensure that the normal position is stored though.
bool hasProperty;
nsPoint normalPosition = cont->GetNormalPosition(&hasProperty);
if (!hasProperty) {
cont->AddProperty(nsIFrame::NormalPositionProperty(), normalPosition);
}
cont->SetPosition(normalPosition +
nsPoint(newOffsets.left, newOffsets.top));
}
}
postPendingScrollAnchorOrResnap(aFrame);
return true;
}
// For the absolute positioning case, set up a fake HTML reflow input for
// the frame, and then get the offsets and size from it. If the frame's size
// doesn't need to change, we can simply update the frame position. Otherwise
// we fall back to a reflow.
UniquePtr<gfxContext> rc =
aFrame->PresShell()->CreateReferenceRenderingContext();
// Construct a bogus parent reflow input so that there's a usable reflow input
// for the containing block.
nsIFrame* parentFrame = aFrame->GetParent();
WritingMode parentWM = parentFrame->GetWritingMode();
WritingMode frameWM = aFrame->GetWritingMode();
LogicalSize parentSize = parentFrame->GetLogicalSize();
nsFrameState savedState = parentFrame->GetStateBits();
ReflowInput parentReflowInput(aFrame->PresContext(), parentFrame, rc.get(),
parentSize);
parentFrame->RemoveStateBits(~nsFrameState(0));
parentFrame->AddStateBits(savedState);
// The bogus parent state here was created with no parent state of its own,
// and therefore it won't have an mCBReflowInput set up.
// But we may need one (for InitCBReflowInput in a child state), so let's
// try to create one here for the cases where it will be needed.
Maybe<ReflowInput> cbReflowInput;
nsIFrame* cbFrame = parentFrame->GetContainingBlock();
if (cbFrame && (aFrame->GetContainingBlock() != parentFrame ||
parentFrame->IsTableFrame())) {
const auto cbWM = cbFrame->GetWritingMode();
LogicalSize cbSize = cbFrame->GetLogicalSize();
cbReflowInput.emplace(cbFrame->PresContext(), cbFrame, rc.get(), cbSize);
cbReflowInput->SetComputedLogicalMargin(
cbWM, cbFrame->GetLogicalUsedMargin(cbWM));
cbReflowInput->SetComputedLogicalPadding(
cbWM, cbFrame->GetLogicalUsedPadding(cbWM));
cbReflowInput->SetComputedLogicalBorderPadding(
cbWM, cbFrame->GetLogicalUsedBorderAndPadding(cbWM));
parentReflowInput.mCBReflowInput = cbReflowInput.ptr();
}
NS_WARNING_ASSERTION(parentSize.ISize(parentWM) != NS_UNCONSTRAINEDSIZE &&
parentSize.BSize(parentWM) != NS_UNCONSTRAINEDSIZE,
"parentSize should be valid");
parentReflowInput.SetComputedISize(std::max(parentSize.ISize(parentWM), 0));
parentReflowInput.SetComputedBSize(std::max(parentSize.BSize(parentWM), 0));
parentReflowInput.SetComputedLogicalMargin(parentWM, LogicalMargin(parentWM));
parentReflowInput.SetComputedLogicalPadding(
parentWM, parentFrame->GetLogicalUsedPadding(parentWM));
parentReflowInput.SetComputedLogicalBorderPadding(
parentWM, parentFrame->GetLogicalUsedBorderAndPadding(parentWM));
LogicalSize availSize = parentSize.ConvertTo(frameWM, parentWM);
availSize.BSize(frameWM) = NS_UNCONSTRAINEDSIZE;
ViewportFrame* viewport = do_QueryFrame(parentFrame);
nsSize cbSize =
viewport
? viewport->AdjustReflowInputAsContainingBlock(&parentReflowInput)
.Size()
: aFrame->GetContainingBlock()->GetSize();
const nsMargin& parentBorder =
parentReflowInput.mStyleBorder->GetComputedBorder();
cbSize -= nsSize(parentBorder.LeftRight(), parentBorder.TopBottom());
LogicalSize lcbSize(frameWM, cbSize);
ReflowInput reflowInput(aFrame->PresContext(), parentReflowInput, aFrame,
availSize, Some(lcbSize));
nscoord computedISize = reflowInput.ComputedISize();
nscoord computedBSize = reflowInput.ComputedBSize();
const auto frameBP = reflowInput.ComputedLogicalBorderPadding(frameWM);
computedISize += frameBP.IStartEnd(frameWM);
if (computedBSize != NS_UNCONSTRAINEDSIZE) {
computedBSize += frameBP.BStartEnd(frameWM);
}
LogicalSize logicalSize = aFrame->GetLogicalSize(frameWM);
nsSize size = aFrame->GetSize();
// The RecomputePosition hint is not used if any offset changed between auto
// and non-auto. If computedSize.height == NS_UNCONSTRAINEDSIZE then the new
// element height will be its intrinsic height, and since 'top' and 'bottom''s
// auto-ness hasn't changed, the old height must also be its intrinsic
// height, which we can assume hasn't changed (or reflow would have
// been triggered).
if (computedISize == logicalSize.ISize(frameWM) &&
(computedBSize == NS_UNCONSTRAINEDSIZE ||
computedBSize == logicalSize.BSize(frameWM))) {
// If we're solving for 'left' or 'top', then compute it here, in order to
// match the reflow code path.
//
// TODO(emilio): It'd be nice if this did logical math instead, but it seems
// to me the math should work out on vertical writing modes as well. See Bug
// 1675861 for some hints.
const nsMargin offset = reflowInput.ComputedPhysicalOffsets();
const nsMargin margin = reflowInput.ComputedPhysicalMargin();
nscoord left = offset.left;
if (left == NS_AUTOOFFSET) {
left =
cbSize.width - offset.right - margin.right - size.width - margin.left;
}
nscoord top = offset.top;
if (top == NS_AUTOOFFSET) {
top = cbSize.height - offset.bottom - margin.bottom - size.height -
margin.top;
}
// Move the frame
nsPoint pos(parentBorder.left + left + margin.left,
parentBorder.top + top + margin.top);
aFrame->SetPosition(pos);
postPendingScrollAnchorOrResnap(aFrame);
return true;
}
// Fall back to a reflow
return false;
}
/**
* Return true if aFrame's subtree has placeholders for out-of-flow content
* that would be affected due to the change to
* `aPossiblyChangingContainingBlock` (and thus would need to get reframed).
*
* In particular, this function returns true if there are placeholders whose OOF
* frames may need to be reparented (via reframing) as a result of whatever
* change actually happened.
*
* The `aIs{Abs,Fixed}PosContainingBlock` params represent whether
* `aPossiblyChangingContainingBlock` is a containing block for abs pos / fixed
* pos stuff, respectively, for the _new_ style that the frame already has, not
* the old one.
*/
static bool ContainingBlockChangeAffectsDescendants(
nsIFrame* aPossiblyChangingContainingBlock, nsIFrame* aFrame,
bool aIsAbsPosContainingBlock, bool aIsFixedPosContainingBlock) {
// All fixed-pos containing blocks should also be abs-pos containing blocks.
MOZ_ASSERT_IF(aIsFixedPosContainingBlock, aIsAbsPosContainingBlock);
for (const auto& childList : aFrame->ChildLists()) {
for (nsIFrame* f : childList.mList) {
if (f->IsPlaceholderFrame()) {
nsIFrame* outOfFlow = nsPlaceholderFrame::GetRealFrameForPlaceholder(f);
// If SVG text frames could appear here, they could confuse us since
// they ignore their position style ... but they can't.
NS_ASSERTION(!outOfFlow->IsInSVGTextSubtree(),
"SVG text frames can't be out of flow");
// Top-layer frames don't change containing block based on direct
// ancestors.
auto* display = outOfFlow->StyleDisplay();
if (display->IsAbsolutelyPositionedStyle() &&
display->mTopLayer == StyleTopLayer::None) {
const bool isContainingBlock =
aIsFixedPosContainingBlock ||
(aIsAbsPosContainingBlock &&
display->mPosition == StylePositionProperty::Absolute);
// NOTE(emilio): aPossiblyChangingContainingBlock is guaranteed to be
// a first continuation, see the assertion in the caller.
nsIFrame* parent = outOfFlow->GetParent()->FirstContinuation();
if (isContainingBlock) {
// If we are becoming a containing block, we only need to reframe if
// this oof's current containing block is an ancestor of the new
// frame.
if (parent != aPossiblyChangingContainingBlock &&
nsLayoutUtils::IsProperAncestorFrame(
parent, aPossiblyChangingContainingBlock)) {
return true;
}
} else {
// If we are not a containing block anymore, we only need to reframe
// if we are the current containing block of the oof frame.
if (parent == aPossiblyChangingContainingBlock) {
return true;
}
}
}
}
// NOTE: It's tempting to check f->IsAbsPosContainingBlock() or
// f->IsFixedPosContainingBlock() here. However, that would only
// be testing the *new* style of the frame, which might exclude
// descendants that currently have this frame as an abs-pos
// containing block. Taking the codepath where we don't reframe
// could lead to an unsafe call to
// cont->MarkAsNotAbsoluteContainingBlock() before we've reframed
// the descendant and taken it off the absolute list.
if (ContainingBlockChangeAffectsDescendants(
aPossiblyChangingContainingBlock, f, aIsAbsPosContainingBlock,
aIsFixedPosContainingBlock)) {
return true;
}
}
}
return false;
}
// Returns the frame that would serve as the containing block for aFrame's
// positioned descendants, if aFrame had styles to make it a CB for such
// descendants. (Typically this is just aFrame itself, or its insertion frame).
//
// Returns nullptr if this frame can't be easily determined.
static nsIFrame* ContainingBlockForFrame(nsIFrame* aFrame) {
if (aFrame->IsFieldSetFrame()) {
// FIXME: This should be easily implementable.
return nullptr;
}
nsIFrame* insertionFrame = aFrame->GetContentInsertionFrame();
if (insertionFrame == aFrame) {
return insertionFrame;
}
// Generally frames with a different insertion frame are hard to deal with,
// but scrollframes are easy because the containing block is just the
// insertion frame.
if (aFrame->IsScrollFrame()) {
return insertionFrame;
}
// Combobox frames are easy as well because they can't have positioned
// children anyways.
// Button and table cell frames are also easy because the containing block is
// the frame itself.
if (aFrame->IsComboboxControlFrame() || aFrame->IsHTMLButtonControlFrame() ||
aFrame->IsTableCellFrame()) {
return aFrame;
}
return nullptr;
}
static bool NeedToReframeToUpdateContainingBlock(nsIFrame* aFrame,
nsIFrame* aMaybeChangingCB) {
// NOTE: This looks at the new style.
const bool isFixedContainingBlock = aFrame->IsFixedPosContainingBlock();
MOZ_ASSERT_IF(isFixedContainingBlock, aFrame->IsAbsPosContainingBlock());
const bool isAbsPosContainingBlock =
isFixedContainingBlock || aFrame->IsAbsPosContainingBlock();
for (nsIFrame* f = aFrame; f;
f = nsLayoutUtils::GetNextContinuationOrIBSplitSibling(f)) {
if (ContainingBlockChangeAffectsDescendants(aMaybeChangingCB, f,
isAbsPosContainingBlock,
isFixedContainingBlock)) {
return true;
}
}
return false;
}
static void DoApplyRenderingChangeToTree(nsIFrame* aFrame,
nsChangeHint aChange) {
MOZ_ASSERT(gInApplyRenderingChangeToTree,
"should only be called within ApplyRenderingChangeToTree");
for (; aFrame;
aFrame = nsLayoutUtils::GetNextContinuationOrIBSplitSibling(aFrame)) {
// Invalidate and sync views on all descendant frames, following
// placeholders. We don't need to update transforms in
// SyncViewsAndInvalidateDescendants, because there can't be any
// out-of-flows or popups that need to be transformed; all out-of-flow
// descendants of the transformed element must also be descendants of the
// transformed frame.
SyncViewsAndInvalidateDescendants(
aFrame, nsChangeHint(aChange & (nsChangeHint_RepaintFrame |
nsChangeHint_UpdateOpacityLayer |
nsChangeHint_SchedulePaint)));
// This must be set to true if the rendering change needs to
// invalidate content. If it's false, a composite-only paint
// (empty transaction) will be scheduled.
bool needInvalidatingPaint = false;
// if frame has view, will already be invalidated
if (aChange & nsChangeHint_RepaintFrame) {
// Note that this whole block will be skipped when painting is suppressed
// (due to our caller ApplyRendingChangeToTree() discarding the
// nsChangeHint_RepaintFrame hint). If you add handling for any other
// hints within this block, be sure that they too should be ignored when
// painting is suppressed.
needInvalidatingPaint = true;
aFrame->InvalidateFrameSubtree();
if ((aChange & nsChangeHint_UpdateEffects) &&
aFrame->HasAnyStateBits(NS_FRAME_SVG_LAYOUT)) {
// Need to update our overflow rects:
SVGUtils::ScheduleReflowSVG(aFrame);
}
ActiveLayerTracker::NotifyNeedsRepaint(aFrame);
}
if (aChange & nsChangeHint_UpdateOpacityLayer) {
// opacity updates in many cases.
needInvalidatingPaint = true;
ActiveLayerTracker::NotifyRestyle(aFrame, eCSSProperty_opacity);
if (SVGIntegrationUtils::UsingEffectsForFrame(aFrame)) {
// SVG effects paints the opacity without using
// nsDisplayOpacity. We need to invalidate manually.
aFrame->InvalidateFrameSubtree();
}
}
if ((aChange & nsChangeHint_UpdateTransformLayer) &&
aFrame->IsTransformed()) {
// Note: All the transform-like properties should map to the same
// layer activity index, so does the restyle count. Therefore, using
// eCSSProperty_transform should be fine.
ActiveLayerTracker::NotifyRestyle(aFrame, eCSSProperty_transform);
needInvalidatingPaint = true;
}
if (aChange & nsChangeHint_ChildrenOnlyTransform) {
needInvalidatingPaint = true;
nsIFrame* childFrame = GetFrameForChildrenOnlyTransformHint(aFrame)
->PrincipalChildList()
.FirstChild();
for (; childFrame; childFrame = childFrame->GetNextSibling()) {
// Note: All the transform-like properties should map to the same
// layer activity index, so does the restyle count. Therefore, using
// eCSSProperty_transform should be fine.
ActiveLayerTracker::NotifyRestyle(childFrame, eCSSProperty_transform);
}
}
if (aChange & nsChangeHint_SchedulePaint) {
needInvalidatingPaint = true;
}
aFrame->SchedulePaint(needInvalidatingPaint
? nsIFrame::PAINT_DEFAULT
: nsIFrame::PAINT_COMPOSITE_ONLY);
}
}
static void SyncViewsAndInvalidateDescendants(nsIFrame* aFrame,
nsChangeHint aChange) {
MOZ_ASSERT(gInApplyRenderingChangeToTree,
"should only be called within ApplyRenderingChangeToTree");
NS_ASSERTION(nsChangeHint_size_t(aChange) ==
(aChange & (nsChangeHint_RepaintFrame |
nsChangeHint_UpdateOpacityLayer |
nsChangeHint_SchedulePaint)),
"Invalid change flag");
aFrame->SyncFrameViewProperties();
for (const auto& [list, listID] : aFrame->ChildLists()) {
for (nsIFrame* child : list) {
if (!child->HasAnyStateBits(NS_FRAME_OUT_OF_FLOW)) {
// only do frames that don't have placeholders
if (child->IsPlaceholderFrame()) {
// do the out-of-flow frame and its continuations
nsIFrame* outOfFlowFrame =
nsPlaceholderFrame::GetRealFrameForPlaceholder(child);
DoApplyRenderingChangeToTree(outOfFlowFrame, aChange);
} else if (listID == FrameChildListID::Popup) {
DoApplyRenderingChangeToTree(child, aChange);
} else { // regular frame
SyncViewsAndInvalidateDescendants(child, aChange);
}
}
}
}
}
static void ApplyRenderingChangeToTree(PresShell* aPresShell, nsIFrame* aFrame,
nsChangeHint aChange) {
// We check StyleDisplay()->HasTransformStyle() in addition to checking
// IsTransformed() since we can get here for some frames that don't support
// CSS transforms, and table frames, which are their own odd-ball, since the
// transform is handled by their wrapper, which _also_ gets a separate hint.
NS_ASSERTION(!(aChange & nsChangeHint_UpdateTransformLayer) ||
aFrame->IsTransformed() ||
aFrame->StyleDisplay()->HasTransformStyle(),
"Unexpected UpdateTransformLayer hint");
if (aPresShell->IsPaintingSuppressed()) {
// Don't allow synchronous rendering changes when painting is turned off.
aChange &= ~nsChangeHint_RepaintFrame;
if (!aChange) {
return;
}
}
// Trigger rendering updates by damaging this frame and any
// continuations of this frame.
#ifdef DEBUG
gInApplyRenderingChangeToTree = true;
#endif
if (aChange & nsChangeHint_RepaintFrame) {
// If the frame is the primary frame of either the body element or
// the html element, we propagate the repaint change hint to the
// viewport. This is necessary for background and scrollbar colors
// propagation.
if (aFrame->IsPrimaryFrameOfRootOrBodyElement()) {
nsIFrame* rootFrame = aPresShell->GetRootFrame();
MOZ_ASSERT(rootFrame, "No root frame?");
DoApplyRenderingChangeToTree(rootFrame, nsChangeHint_RepaintFrame);
aChange &= ~nsChangeHint_RepaintFrame;
if (!aChange) {
return;
}
}
}
DoApplyRenderingChangeToTree(aFrame, aChange);
#ifdef DEBUG
gInApplyRenderingChangeToTree = false;
#endif
}
static void AddSubtreeToOverflowTracker(
nsIFrame* aFrame, OverflowChangedTracker& aOverflowChangedTracker) {
if (aFrame->FrameMaintainsOverflow()) {
aOverflowChangedTracker.AddFrame(aFrame,
OverflowChangedTracker::CHILDREN_CHANGED);
}
for (const auto& childList : aFrame->ChildLists()) {
for (nsIFrame* child : childList.mList) {
AddSubtreeToOverflowTracker(child, aOverflowChangedTracker);
}
}
}
static void StyleChangeReflow(nsIFrame* aFrame, nsChangeHint aHint) {
IntrinsicDirty dirtyType;
if (aHint & nsChangeHint_ClearDescendantIntrinsics) {
NS_ASSERTION(aHint & nsChangeHint_ClearAncestorIntrinsics,
"Please read the comments in nsChangeHint.h");
NS_ASSERTION(aHint & nsChangeHint_NeedDirtyReflow,
"ClearDescendantIntrinsics requires NeedDirtyReflow");
dirtyType = IntrinsicDirty::FrameAncestorsAndDescendants;
} else if ((aHint & nsChangeHint_UpdateComputedBSize) &&
aFrame->HasAnyStateBits(
NS_FRAME_DESCENDANT_INTRINSIC_ISIZE_DEPENDS_ON_BSIZE)) {
dirtyType = IntrinsicDirty::FrameAncestorsAndDescendants;
} else if (aHint & nsChangeHint_ClearAncestorIntrinsics) {
dirtyType = IntrinsicDirty::FrameAndAncestors;
} else {
dirtyType = IntrinsicDirty::None;
}
if (aHint & nsChangeHint_UpdateComputedBSize) {
aFrame->SetHasBSizeChange(true);
}
nsFrameState dirtyBits;
if (aFrame->HasAnyStateBits(NS_FRAME_FIRST_REFLOW)) {
dirtyBits = nsFrameState(0);
} else if ((aHint & nsChangeHint_NeedDirtyReflow) ||
dirtyType == IntrinsicDirty::FrameAncestorsAndDescendants) {
dirtyBits = NS_FRAME_IS_DIRTY;
} else {
dirtyBits = NS_FRAME_HAS_DIRTY_CHILDREN;
}
// If we're not going to clear any intrinsic sizes on the frames, and
// there are no dirty bits to set, then there's nothing to do.
if (dirtyType == IntrinsicDirty::None && !dirtyBits) return;
ReflowRootHandling rootHandling;
if (aHint & nsChangeHint_ReflowChangesSizeOrPosition) {
rootHandling = ReflowRootHandling::PositionOrSizeChange;
} else {
rootHandling = ReflowRootHandling::NoPositionOrSizeChange;
}
do {
aFrame->PresShell()->FrameNeedsReflow(aFrame, dirtyType, dirtyBits,
rootHandling);
aFrame = nsLayoutUtils::GetNextContinuationOrIBSplitSibling(aFrame);
} while (aFrame);
}
// Get the next sibling which might have a frame. This only considers siblings
// that stylo post-traversal looks at, so only elements and text. In
// particular, it ignores comments.
static nsIContent* NextSiblingWhichMayHaveFrame(nsIContent* aContent) {
for (nsIContent* next = aContent->GetNextSibling(); next;
next = next->GetNextSibling()) {
if (next->IsElement() || next->IsText()) {
return next;
}
}
return nullptr;
}
// If |aFrame| is dirty or has dirty children, then we can skip updating
// overflows since that will happen when it's reflowed.
static inline bool CanSkipOverflowUpdates(const nsIFrame* aFrame) {
return aFrame->HasAnyStateBits(NS_FRAME_IS_DIRTY |
NS_FRAME_HAS_DIRTY_CHILDREN);
}
static inline void TryToDealWithScrollbarChange(nsChangeHint& aHint,
nsIContent* aContent,
nsIFrame* aFrame,
nsPresContext* aPc) {
if (!(aHint & nsChangeHint_ScrollbarChange)) {
return;
}
aHint &= ~nsChangeHint_ScrollbarChange;
if (aHint & nsChangeHint_ReconstructFrame) {
return;
}
MOZ_ASSERT(aFrame, "If we're not reframing, we ought to have a frame");
const bool isRoot = aContent->IsInUncomposedDoc() && !aContent->GetParent();
// Only bother with this if we're the root or the body element, since:
// (a) It'd be *expensive* to reframe these particular nodes. They're
// at the root, so reframing would mean rebuilding the world.
// (b) It's often *unnecessary* to reframe for "overflow" changes on
// these particular nodes. In general, the only reason we reframe
// for "overflow" changes is so we can construct (or destroy) a
// scrollframe & scrollbars -- and the html/body nodes often don't
// need their own scrollframe/scrollbars because they coopt the ones
// on the viewport (which always exist). So depending on whether
// that's happening, we can skip the reframe for these nodes.
if (isRoot || aContent->IsHTMLElement(nsGkAtoms::body)) {
// If the restyled element provided/provides the scrollbar styles for
// the viewport before and/or after this restyle, AND it's not coopting
// that responsibility from some other element (which would need
// reconstruction to make its own scrollframe now), THEN: we don't need
// to reconstruct - we can just reflow, because no scrollframe is being
// added/removed.
Element* prevOverride = aPc->GetViewportScrollStylesOverrideElement();
Element* newOverride = aPc->UpdateViewportScrollStylesOverride();
const auto ProvidesScrollbarStyles = [&](nsIContent* aOverride) {
if (aOverride) {
return aOverride == aContent;
}
return isRoot;
};
if (ProvidesScrollbarStyles(prevOverride) ||
ProvidesScrollbarStyles(newOverride)) {
// If we get here, the restyled element provided the scrollbar styles
// for viewport before this restyle, OR it will provide them after.
if (!prevOverride || !newOverride || prevOverride == newOverride) {
// If we get here, the restyled element is NOT replacing (or being
// replaced by) some other element as the viewport's
// scrollbar-styles provider. (If it were, we'd potentially need to
// reframe to create a dedicated scrollframe for whichever element
// is being booted from providing viewport scrollbar styles.)
//
// Under these conditions, we're OK to assume that this "overflow"
// change only impacts the root viewport's scrollframe, which
// already exists, so we can simply reflow instead of reframing.
if (nsIScrollableFrame* sf = do_QueryFrame(aFrame)) {
sf->MarkScrollbarsDirtyForReflow();
} else if (nsIScrollableFrame* sf =
aPc->PresShell()->GetRootScrollFrameAsScrollable()) {
sf->MarkScrollbarsDirtyForReflow();
}
aHint |= nsChangeHint_ReflowHintsForScrollbarChange;
} else {
// If we changed the override element, we need to reconstruct as the old
// override element might start / stop being scrollable.
aHint |= nsChangeHint_ReconstructFrame;
}
return;
}
}
const bool scrollable = aFrame->StyleDisplay()->IsScrollableOverflow();
if (nsIScrollableFrame* sf = do_QueryFrame(aFrame)) {
if (scrollable && sf->HasAllNeededScrollbars()) {
sf->MarkScrollbarsDirtyForReflow();
// Once we've created scrollbars for a frame, don't bother reconstructing
// it just to remove them if we still need a scroll frame.
aHint |= nsChangeHint_ReflowHintsForScrollbarChange;
return;
}
} else if (aFrame->IsTextInputFrame()) {
// input / textarea for the most part don't honor overflow themselves, the
// editor root will deal with the change if needed.
// However the textarea intrinsic size relies on GetDesiredScrollbarSizes(),
// so we need to reflow the textarea itself, not just the inner control.
aHint |= nsChangeHint_ReflowHintsForScrollbarChange;
return;
} else if (!scrollable) {
// Something changed, but we don't have nor will have a scroll frame,
// there's nothing to do here.
return;
}
// Oh well, we couldn't optimize it out, just reconstruct frames for the
// subtree.
aHint |= nsChangeHint_ReconstructFrame;
}
static void TryToHandleContainingBlockChange(nsChangeHint& aHint,
nsIFrame* aFrame) {
if (!(aHint & nsChangeHint_UpdateContainingBlock)) {
return;
}
if (aHint & nsChangeHint_ReconstructFrame) {
return;
}
MOZ_ASSERT(aFrame, "If we're not reframing, we ought to have a frame");
nsIFrame* containingBlock = ContainingBlockForFrame(aFrame);
if (!containingBlock ||
NeedToReframeToUpdateContainingBlock(aFrame, containingBlock)) {
// The frame has positioned children that need to be reparented, or it can't
// easily be converted to/from being an abs-pos container correctly.
aHint |= nsChangeHint_ReconstructFrame;
return;
}
const bool isCb = aFrame->IsAbsPosContainingBlock();
// The absolute container should be containingBlock.
for (nsIFrame* cont = containingBlock; cont;
cont = nsLayoutUtils::GetNextContinuationOrIBSplitSibling(cont)) {
// Normally frame construction would set state bits as needed,
// but we're not going to reconstruct the frame so we need to set
// them. It's because we need to set this state on each affected frame
// that we can't coalesce nsChangeHint_UpdateContainingBlock hints up
// to ancestors (i.e. it can't be an change hint that is handled for
// descendants).
if (isCb) {
if (!cont->IsAbsoluteContainer() &&
cont->HasAnyStateBits(NS_FRAME_CAN_HAVE_ABSPOS_CHILDREN)) {
cont->MarkAsAbsoluteContainingBlock();
}
} else if (cont->IsAbsoluteContainer()) {
if (cont->HasAbsolutelyPositionedChildren()) {
// If |cont| still has absolutely positioned children,
// we can't call MarkAsNotAbsoluteContainingBlock. This
// will remove a frame list that still has children in
// it that we need to keep track of.
// The optimization of removing it isn't particularly
// important, although it does mean we skip some tests.
NS_WARNING("skipping removal of absolute containing block");
} else {
cont->MarkAsNotAbsoluteContainingBlock();
}
}
}
}
void RestyleManager::ProcessRestyledFrames(nsStyleChangeList& aChangeList) {
NS_ASSERTION(!nsContentUtils::IsSafeToRunScript(),
"Someone forgot a script blocker");
// Recursive calls here are a bit worrying, but apparently do happen in the
// wild (although not currently in any of our automated tests). Try to get a
// stack from Nightly/Dev channel to figure out what's going on and whether
// it's OK.
MOZ_DIAGNOSTIC_ASSERT(!mDestroyedFrames, "ProcessRestyledFrames recursion");
if (aChangeList.IsEmpty()) {
return;
}
// If mDestroyedFrames is null, we want to create a new hashtable here
// and destroy it on exit; but if it is already non-null (because we're in
// a recursive call), we will continue to use the existing table to
// accumulate destroyed frames, and NOT clear mDestroyedFrames on exit.
// We use a MaybeClearDestroyedFrames helper to conditionally reset the
// mDestroyedFrames pointer when this method returns.
typedef decltype(mDestroyedFrames) DestroyedFramesT;
class MOZ_RAII MaybeClearDestroyedFrames {
private:
DestroyedFramesT& mDestroyedFramesRef; // ref to caller's mDestroyedFrames
const bool mResetOnDestruction;
public:
explicit MaybeClearDestroyedFrames(DestroyedFramesT& aTarget)
: mDestroyedFramesRef(aTarget),
mResetOnDestruction(!aTarget) // reset only if target starts out null
{}
~MaybeClearDestroyedFrames() {
if (mResetOnDestruction) {
mDestroyedFramesRef.reset(nullptr);
}
}
};
MaybeClearDestroyedFrames maybeClear(mDestroyedFrames);
if (!mDestroyedFrames) {
mDestroyedFrames = MakeUnique<nsTHashSet<const nsIFrame*>>();
}
AUTO_PROFILER_LABEL("RestyleManager::ProcessRestyledFrames", LAYOUT);
nsPresContext* presContext = PresContext();
nsCSSFrameConstructor* frameConstructor = presContext->FrameConstructor();
bool didUpdateCursor = false;
for (size_t i = 0; i < aChangeList.Length(); ++i) {
// Collect and coalesce adjacent siblings for lazy frame construction.
// Eventually it would be even better to make RecreateFramesForContent
size_t lazyRangeStart = i;
while (i < aChangeList.Length() && aChangeList[i].mContent &&
aChangeList[i].mContent->HasFlag(NODE_NEEDS_FRAME) &&
(i == lazyRangeStart ||
NextSiblingWhichMayHaveFrame(aChangeList[i - 1].mContent) ==
aChangeList[i].mContent)) {
MOZ_ASSERT(aChangeList[i].mHint & nsChangeHint_ReconstructFrame);
MOZ_ASSERT(!aChangeList[i].mFrame);
++i;
}
if (i != lazyRangeStart) {
nsIContent* start = aChangeList[lazyRangeStart].mContent;
nsIContent* end =
NextSiblingWhichMayHaveFrame(aChangeList[i - 1].mContent);
if (!end) {
frameConstructor->ContentAppended(
start, nsCSSFrameConstructor::InsertionKind::Sync);
} else {
frameConstructor->ContentRangeInserted(
start, end, nsCSSFrameConstructor::InsertionKind::Sync);
}
}
for (size_t j = lazyRangeStart; j < i; ++j) {
MOZ_ASSERT(!aChangeList[j].mContent->GetPrimaryFrame() ||
!aChangeList[j].mContent->HasFlag(NODE_NEEDS_FRAME));
}
if (i == aChangeList.Length()) {
break;
}
const nsStyleChangeData& data = aChangeList[i];
nsIFrame* frame = data.mFrame;
nsIContent* content = data.mContent;
nsChangeHint hint = data.mHint;
bool didReflowThisFrame = false;
NS_ASSERTION(!(hint & nsChangeHint_AllReflowHints) ||
(hint & nsChangeHint_NeedReflow),
"Reflow hint bits set without actually asking for a reflow");
// skip any frame that has been destroyed due to a ripple effect
if (frame && mDestroyedFrames->Contains(frame)) {
continue;
}
if (frame && frame->GetContent() != content) {
// XXXbz this is due to image maps messing with the primary frame of
frame = nullptr;
if (!(hint & nsChangeHint_ReconstructFrame)) {
continue;
}
}
TryToDealWithScrollbarChange(hint, content, frame, presContext);
TryToHandleContainingBlockChange(hint, frame);
if (hint & nsChangeHint_ReconstructFrame) {
// If we ever start passing true here, be careful of restyles
// that involve a reframe and animations. In particular, if the
// restyle we're processing here is an animation restyle, but
// the style resolution we will do for the frame construction
// happens async when we're not in an animation restyle already,
// problems could arise.
// We could also have problems with triggering of CSS transitions
// on elements whose frames are reconstructed, since we depend on
// the reconstruction happening synchronously.
frameConstructor->RecreateFramesForContent(
content, nsCSSFrameConstructor::InsertionKind::Sync);
continue;
}
MOZ_ASSERT(frame, "This shouldn't happen");
if (hint & nsChangeHint_AddOrRemoveTransform) {
for (nsIFrame* cont = frame; cont;
cont = nsLayoutUtils::GetNextContinuationOrIBSplitSibling(cont)) {
if (cont->StyleDisplay()->HasTransform(cont)) {
cont->AddStateBits(NS_FRAME_MAY_BE_TRANSFORMED);
}
// Don't remove NS_FRAME_MAY_BE_TRANSFORMED since it may still be
// transformed by other means. It's OK to have the bit even if it's
// not needed.
}
// When dropping a running transform animation we will first add an
// nsChangeHint_UpdateTransformLayer hint as part of the animation-only
// restyle. During the subsequent regular restyle, if the animation was
// the only reason the element had any transform applied, we will add
// nsChangeHint_AddOrRemoveTransform as part of the regular restyle.
//
// With the Gecko backend, these two change hints are processed
// after each restyle but when using the Servo backend they accumulate
// and are processed together after we have already removed the
// transform as part of the regular restyle. Since we don't actually
// need the nsChangeHint_UpdateTransformLayer hint if we already have
// a nsChangeHint_AddOrRemoveTransform hint, and since we
// will fail an assertion in ApplyRenderingChangeToTree if we try
// specify nsChangeHint_UpdateTransformLayer but don't have any
// transform style, we just drop the unneeded hint here.
hint &= ~nsChangeHint_UpdateTransformLayer;
}
if (!frame->FrameMaintainsOverflow()) {
// frame does not maintain overflow rects, so avoid calling
// FinishAndStoreOverflow on it:
hint &=
~(nsChangeHint_UpdateOverflow | nsChangeHint_ChildrenOnlyTransform |
nsChangeHint_UpdatePostTransformOverflow |
nsChangeHint_UpdateParentOverflow |
nsChangeHint_UpdateSubtreeOverflow);
}
if (!frame->HasAnyStateBits(NS_FRAME_MAY_BE_TRANSFORMED)) {
// Frame can not be transformed, and thus a change in transform will
// have no effect and we should not use either
// nsChangeHint_UpdatePostTransformOverflow or
// nsChangeHint_UpdateTransformLayerhint.
hint &= ~(nsChangeHint_UpdatePostTransformOverflow |
nsChangeHint_UpdateTransformLayer);
}
if ((hint & nsChangeHint_UpdateEffects) &&
frame == nsLayoutUtils::FirstContinuationOrIBSplitSibling(frame)) {
SVGObserverUtils::UpdateEffects(frame);
}
if ((hint & nsChangeHint_InvalidateRenderingObservers) ||
((hint & nsChangeHint_UpdateOpacityLayer) &&
frame->HasAnyStateBits(NS_FRAME_SVG_LAYOUT))) {
SVGObserverUtils::InvalidateRenderingObservers(frame);
frame->SchedulePaint();
}
if (hint & nsChangeHint_NeedReflow) {
StyleChangeReflow(frame, hint);
didReflowThisFrame = true;
}
// Here we need to propagate repaint frame change hint instead of update
// opacity layer change hint when we do opacity optimization for SVG.
// We can't do it in nsStyleEffects::CalcDifference() just like we do
// for the optimization for 0.99 over opacity values since we have no way
// to call SVGUtils::CanOptimizeOpacity() there.
if ((hint & nsChangeHint_UpdateOpacityLayer) &&
SVGUtils::CanOptimizeOpacity(frame)) {
hint &= ~nsChangeHint_UpdateOpacityLayer;
hint |= nsChangeHint_RepaintFrame;
}
if ((hint & nsChangeHint_UpdateUsesOpacity) && frame->IsTablePart()) {
NS_ASSERTION(hint & nsChangeHint_UpdateOpacityLayer,
"should only return UpdateUsesOpacity hint "
"when also returning UpdateOpacityLayer hint");
// When an internal table part (including cells) changes between
// having opacity 1 and non-1, it changes whether its
// backgrounds (and those of table parts inside of it) are
// painted as part of the table's nsDisplayTableBorderBackground
// display item, or part of its own display item. That requires
// invalidation, so change UpdateOpacityLayer to RepaintFrame.
hint &= ~nsChangeHint_UpdateOpacityLayer;
hint |= nsChangeHint_RepaintFrame;
}
// Opacity disables preserve-3d, so if we toggle it, then we also need
// to update the overflow areas of all potentially affected frames.
if ((hint & nsChangeHint_UpdateUsesOpacity) &&
frame->StyleDisplay()->mTransformStyle ==
StyleTransformStyle::Preserve3d) {
hint |= nsChangeHint_UpdateSubtreeOverflow;
}
if (hint & nsChangeHint_UpdateBackgroundPosition) {
// For most frame types, DLBI can detect background position changes,
// so we only need to schedule a paint.
hint |= nsChangeHint_SchedulePaint;
if (frame->IsTablePart() || frame->IsMathMLFrame()) {
// Table parts and MathML frames don't build display items for their
// backgrounds, so DLBI can't detect background-position changes for
// these frames. Repaint the whole frame.
hint |= nsChangeHint_RepaintFrame;
}
}
if (hint &
(nsChangeHint_RepaintFrame | nsChangeHint_UpdateOpacityLayer |
nsChangeHint_UpdateTransformLayer |
nsChangeHint_ChildrenOnlyTransform | nsChangeHint_SchedulePaint)) {
ApplyRenderingChangeToTree(presContext->PresShell(), frame, hint);
}
if (hint & (nsChangeHint_UpdateTransformLayer |
nsChangeHint_AddOrRemoveTransform)) {
// We need to trigger re-snapping to this content if we snapped to the
// content on the last scroll operation.
ScrollSnapUtils::PostPendingResnapIfNeededFor(frame);
}
if ((hint & nsChangeHint_RecomputePosition) && !didReflowThisFrame) {
// It is possible for this to fall back to a reflow
if (!RecomputePosition(frame)) {
StyleChangeReflow(frame, nsChangeHint_NeedReflow |
nsChangeHint_ReflowChangesSizeOrPosition);
didReflowThisFrame = true;
}
}
NS_ASSERTION(!(hint & nsChangeHint_ChildrenOnlyTransform) ||
(hint & nsChangeHint_UpdateOverflow),
"nsChangeHint_UpdateOverflow should be passed too");
if (!didReflowThisFrame &&
(hint & (nsChangeHint_UpdateOverflow |
nsChangeHint_UpdatePostTransformOverflow |
nsChangeHint_UpdateParentOverflow |
nsChangeHint_UpdateSubtreeOverflow))) {
if (hint & nsChangeHint_UpdateSubtreeOverflow) {
for (nsIFrame* cont = frame; cont;
cont = nsLayoutUtils::GetNextContinuationOrIBSplitSibling(cont)) {
AddSubtreeToOverflowTracker(cont, mOverflowChangedTracker);
}
// The work we just did in AddSubtreeToOverflowTracker
// subsumes some of the other hints:
hint &= ~(nsChangeHint_UpdateOverflow |
nsChangeHint_UpdatePostTransformOverflow);
}
if (hint & nsChangeHint_ChildrenOnlyTransform) {
// We need to update overflows. The correct frame(s) to update depends
// on whether the ChangeHint came from an outer or an inner svg.
nsIFrame* hintFrame = GetFrameForChildrenOnlyTransformHint(frame);
NS_ASSERTION(!nsLayoutUtils::GetNextContinuationOrIBSplitSibling(frame),
"SVG frames should not have continuations "
"or ib-split siblings");
NS_ASSERTION(
!nsLayoutUtils::GetNextContinuationOrIBSplitSibling(hintFrame),
"SVG frames should not have continuations "
"or ib-split siblings");
if (hintFrame->IsSVGOuterSVGAnonChildFrame()) {
// The children only transform of an outer svg frame is applied to
// the outer svg's anonymous child frame (instead of to the
// anonymous child's children).
if (!CanSkipOverflowUpdates(hintFrame)) {
mOverflowChangedTracker.AddFrame(
hintFrame, OverflowChangedTracker::CHILDREN_CHANGED);
}
} else {
// The children only transform is applied to the child frames of an
// inner svg frame, so update the child overflows.
nsIFrame* childFrame = hintFrame->PrincipalChildList().FirstChild();
for (; childFrame; childFrame = childFrame->GetNextSibling()) {
MOZ_ASSERT(childFrame->IsSVGFrame(),
"Not expecting non-SVG children");
if (!CanSkipOverflowUpdates(childFrame)) {
mOverflowChangedTracker.AddFrame(
childFrame, OverflowChangedTracker::CHILDREN_CHANGED);
}
NS_ASSERTION(
!nsLayoutUtils::GetNextContinuationOrIBSplitSibling(childFrame),
"SVG frames should not have continuations "
"or ib-split siblings");
NS_ASSERTION(
childFrame->GetParent() == hintFrame,
"SVG child frame not expected to have different parent");
}
}
}
if (!CanSkipOverflowUpdates(frame)) {
if (hint & (nsChangeHint_UpdateOverflow |
nsChangeHint_UpdatePostTransformOverflow)) {
OverflowChangedTracker::ChangeKind changeKind;
// If we have both nsChangeHint_UpdateOverflow and
// nsChangeHint_UpdatePostTransformOverflow,
// CHILDREN_CHANGED is selected as it is
// strictly stronger.
if (hint & nsChangeHint_UpdateOverflow) {
changeKind = OverflowChangedTracker::CHILDREN_CHANGED;
} else {
changeKind = OverflowChangedTracker::TRANSFORM_CHANGED;
}
for (nsIFrame* cont = frame; cont;
cont =
nsLayoutUtils::GetNextContinuationOrIBSplitSibling(cont)) {
mOverflowChangedTracker.AddFrame(cont, changeKind);
}
}
// UpdateParentOverflow hints need to be processed in addition
// to the above, since if the processing of the above hints
// yields no change, the update will not propagate to the
// parent.
if (hint & nsChangeHint_UpdateParentOverflow) {
MOZ_ASSERT(frame->GetParent(),
"shouldn't get style hints for the root frame");
for (nsIFrame* cont = frame; cont;
cont =
nsLayoutUtils::GetNextContinuationOrIBSplitSibling(cont)) {
mOverflowChangedTracker.AddFrame(
cont->GetParent(), OverflowChangedTracker::CHILDREN_CHANGED);
}
}
}
}
if ((hint & nsChangeHint_UpdateCursor) && !didUpdateCursor) {
presContext->PresShell()->SynthesizeMouseMove(false);
didUpdateCursor = true;
}
if (hint & nsChangeHint_UpdateTableCellSpans) {
frameConstructor->UpdateTableCellSpans(content);
}
if (hint & nsChangeHint_VisibilityChange) {
frame->UpdateVisibleDescendantsState();
}
}
aChangeList.Clear();
FlushOverflowChangedTracker();
}
/* static */
uint64_t RestyleManager::GetAnimationGenerationForFrame(nsIFrame* aStyleFrame) {
EffectSet* effectSet = EffectSet::GetForStyleFrame(aStyleFrame);
return effectSet ? effectSet->GetAnimationGeneration() : 0;
}
void RestyleManager::IncrementAnimationGeneration() {
// We update the animation generation at start of each call to
// ProcessPendingRestyles so we should ignore any subsequent (redundant)
// calls that occur while we are still processing restyles.
if (!mInStyleRefresh) {
++mAnimationGeneration;
}
}
/* static */
void RestyleManager::AddLayerChangesForAnimation(
nsIFrame* aStyleFrame, nsIFrame* aPrimaryFrame, Element* aElement,
nsChangeHint aHintForThisFrame, nsStyleChangeList& aChangeListToProcess) {
MOZ_ASSERT(aElement);
MOZ_ASSERT(!!aStyleFrame == !!aPrimaryFrame);
if (!aStyleFrame) {
return;
}
uint64_t frameGeneration =
RestyleManager::GetAnimationGenerationForFrame(aStyleFrame);
Maybe<nsCSSPropertyIDSet> effectiveAnimationProperties;
nsChangeHint hint = nsChangeHint(0);
auto maybeApplyChangeHint = [&](const Maybe<uint64_t>& aGeneration,
DisplayItemType aDisplayItemType) -> bool {
if (aGeneration && frameGeneration != *aGeneration) {
// If we have a transform layer but don't have any transform style, we
// probably just removed the transform but haven't destroyed the layer
// yet. In this case we will typically add the appropriate change hint
// (nsChangeHint_UpdateContainingBlock) when we compare styles so in
// theory we could skip adding any change hint here.
//
// However, sometimes when we compare styles we'll get no change. For
// example, if the transform style was 'none' when we sent the transform
// animation to the compositor and the current transform style is now
// 'none' we'll think nothing changed but actually we still need to
// trigger an update to clear whatever style the transform animation set
// on the compositor. To handle this case we simply set all the change
// hints relevant to removing transform style (since we don't know exactly
// what changes happened while the animation was running on the
// compositor).
//
// Note that we *don't* add nsChangeHint_UpdateTransformLayer since if we
// did, ApplyRenderingChangeToTree would complain that we're updating a
// transform layer without a transform.
if (aDisplayItemType == DisplayItemType::TYPE_TRANSFORM &&
!aStyleFrame->StyleDisplay()->HasTransformStyle()) {
// Add all the hints for a removing a transform if they are not already
// set for this frame.
if (!(NS_IsHintSubset(nsChangeHint_ComprehensiveAddOrRemoveTransform,
aHintForThisFrame))) {
hint |= nsChangeHint_ComprehensiveAddOrRemoveTransform;
}
return true;
}
hint |= LayerAnimationInfo::GetChangeHintFor(aDisplayItemType);
}
// We consider it's the first paint for the frame if we have an animation
// for the property but have no layer, for the case of WebRender, no
// corresponding animation info.
// Note that in case of animations which has properties preventing running
// on the compositor, e.g., width or height, corresponding layer is not
// created at all, but even in such cases, we normally set valid change
// hint for such animations in each tick, i.e. restyles in each tick. As
// a result, we usually do restyles for such animations in every tick on
// the main-thread. The only animations which will be affected by this
// explicit change hint are animations that have opacity/transform but did
// not have those properies just before. e.g, setting transform by
// setKeyframes or changing target element from other target which prevents
// running on the compositor, etc.
if (!aGeneration) {
nsChangeHint hintForDisplayItem =
LayerAnimationInfo::GetChangeHintFor(aDisplayItemType);
// We don't need to apply the corresponding change hint if we already have
// it.
if (NS_IsHintSubset(hintForDisplayItem, aHintForThisFrame)) {
return true;
}
if (!effectiveAnimationProperties) {
effectiveAnimationProperties.emplace(
nsLayoutUtils::GetAnimationPropertiesForCompositor(aStyleFrame));
}
const nsCSSPropertyIDSet& propertiesForDisplayItem =
LayerAnimationInfo::GetCSSPropertiesFor(aDisplayItemType);
if (effectiveAnimationProperties->Intersects(propertiesForDisplayItem)) {
hint |= hintForDisplayItem;
}
}
return true;
};
AnimationInfo::EnumerateGenerationOnFrame(
aStyleFrame, aElement, LayerAnimationInfo::sDisplayItemTypes,
maybeApplyChangeHint);
if (hint) {
// We apply the hint to the primary frame, not the style frame. Transform
// and opacity hints apply to the table wrapper box, not the table box.
aChangeListToProcess.AppendChange(aPrimaryFrame, aElement, hint);
}
}
RestyleManager::AnimationsWithDestroyedFrame::AnimationsWithDestroyedFrame(
RestyleManager* aRestyleManager)
: mRestyleManager(aRestyleManager),
mRestorePointer(mRestyleManager->mAnimationsWithDestroyedFrame) {
MOZ_ASSERT(!mRestyleManager->mAnimationsWithDestroyedFrame,
"shouldn't construct recursively");
mRestyleManager->mAnimationsWithDestroyedFrame = this;
}
void RestyleManager::AnimationsWithDestroyedFrame ::
StopAnimationsForElementsWithoutFrames() {
StopAnimationsWithoutFrame(mContents, PseudoStyleType::NotPseudo);
StopAnimationsWithoutFrame(mBeforeContents, PseudoStyleType::before);
StopAnimationsWithoutFrame(mAfterContents, PseudoStyleType::after);
StopAnimationsWithoutFrame(mMarkerContents, PseudoStyleType::marker);
}
void RestyleManager::AnimationsWithDestroyedFrame ::StopAnimationsWithoutFrame(
nsTArray<RefPtr<nsIContent>>& aArray, PseudoStyleType aPseudoType) {
nsAnimationManager* animationManager =
mRestyleManager->PresContext()->AnimationManager();
nsTransitionManager* transitionManager =
mRestyleManager->PresContext()->TransitionManager();
for (nsIContent* content : aArray) {
if (aPseudoType == PseudoStyleType::NotPseudo) {
if (content->GetPrimaryFrame()) {
continue;
}
} else if (aPseudoType == PseudoStyleType::before) {
if (nsLayoutUtils::GetBeforeFrame(content)) {
continue;
}
} else if (aPseudoType == PseudoStyleType::after) {
if (nsLayoutUtils::GetAfterFrame(content)) {
continue;
}
} else if (aPseudoType == PseudoStyleType::marker) {
if (nsLayoutUtils::GetMarkerFrame(content)) {
continue;
}
}
dom::Element* element = content->AsElement();
animationManager->StopAnimationsForElement(element, aPseudoType);
transitionManager->StopAnimationsForElement(element, aPseudoType);
// All other animations should keep running but not running on the
// *compositor* at this point.
if (EffectSet* effectSet = EffectSet::Get(element, aPseudoType)) {
for (KeyframeEffect* effect : *effectSet) {
effect->ResetIsRunningOnCompositor();
}
}
}
}
// When using handled hints by an ancestor, we need to make sure that our
// ancestor in the DOM tree is actually our ancestor in the flat tree.
// Otherwise, we can't guarantee that e.g. a repaint from an ancestor in the DOM
// will really end up repainting us.
static bool CanUseHandledHintsFromAncestors(const nsIFrame* aFrame) {
if (aFrame->HasAnyStateBits(NS_FRAME_OUT_OF_FLOW)) {
// An out of flow can be parented in other part of the tree.
return false;
}
if (aFrame->IsColumnSpanInMulticolSubtree()) {
// Any column-spanner's parent frame is not its DOM parent's primary frame.
return false;
}
if (aFrame->IsTableCaption()) {
// This one is more subtle. captions are in-flow children of the table
// frame. But they are parented to the table wrapper. So hints handled for
// the inner table might not be applicable to us.
return false;
}
return true;
}
#ifdef DEBUG
static bool IsAnonBox(const nsIFrame* aFrame) {
return aFrame->Style()->IsAnonBox();
}
static const nsIFrame* FirstContinuationOrPartOfIBSplit(
const nsIFrame* aFrame) {
if (!aFrame) {
return nullptr;
}
return nsLayoutUtils::FirstContinuationOrIBSplitSibling(aFrame);
}
static const nsIFrame* ExpectedOwnerForChild(const nsIFrame* aFrame) {
const nsIFrame* parent = aFrame->GetParent();
if (aFrame->IsTableFrame()) {
MOZ_ASSERT(parent->IsTableWrapperFrame());
parent = parent->GetParent();
}
if (IsAnonBox(aFrame) && !aFrame->IsTextFrame()) {
if (parent->IsLineFrame()) {
parent = parent->GetParent();
}
return parent->IsViewportFrame() ? nullptr
: FirstContinuationOrPartOfIBSplit(parent);
}
if (aFrame->IsLineFrame()) {
// A ::first-line always ends up here via its block, which is therefore the
// right expected owner. That block can be an
// anonymous box. For example, we could have a ::first-line on a columnated
// block; the blockframe is the column-content anonymous box in that case.
// So we don't want to end up in the code below, which steps out of anon
// boxes. Just return the parent of the line frame, which is the block.
return parent;
}
if (aFrame->IsLetterFrame()) {
// Ditto for ::first-letter. A first-letter always arrives here via its
// direct parent, except when it's parented to a ::first-line.
if (parent->IsLineFrame()) {
parent = parent->GetParent();
}
return FirstContinuationOrPartOfIBSplit(parent);
}
if (parent->IsLetterFrame()) {
// Things never have ::first-letter as their expected parent. Go
// on up to the ::first-letter's parent.
parent = parent->GetParent();
}
parent = FirstContinuationOrPartOfIBSplit(parent);
// We've handled already anon boxes, so now we're looking at
// a frame of a DOM element or pseudo. Hop through anon and line-boxes
// generated by our DOM parent, and go find the owner frame for it.
while (parent && (IsAnonBox(parent) || parent->IsLineFrame())) {
auto pseudo = parent->Style()->GetPseudoType();
if (pseudo == PseudoStyleType::tableWrapper) {
const nsIFrame* tableFrame = parent->PrincipalChildList().FirstChild();
MOZ_ASSERT(tableFrame->IsTableFrame());
// Handle :-moz-table and :-moz-inline-table.
parent = IsAnonBox(tableFrame) ? parent->GetParent() : tableFrame;
} else {
// We get the in-flow parent here so that we can handle the OOF anonymous
// boxed to get the correct parent.
parent = parent->GetInFlowParent();
}
parent = FirstContinuationOrPartOfIBSplit(parent);
}
return parent;
}
// restyle replicated fixed pos frames... We seem to assume everywhere that they
// can't get restyled at the moment...
static bool IsInReplicatedFixedPosTree(const nsIFrame* aFrame) {
if (!aFrame->PresContext()->IsPaginated()) {
return false;
}
for (; aFrame; aFrame = aFrame->GetParent()) {
if (aFrame->StyleDisplay()->mPosition == StylePositionProperty::Fixed &&
!aFrame->FirstContinuation()->IsPrimaryFrame() &&
nsLayoutUtils::IsReallyFixedPos(aFrame)) {
return true;
}
}
return true;
}
void ServoRestyleState::AssertOwner(const ServoRestyleState& aParent) const {
MOZ_ASSERT(mOwner);
MOZ_ASSERT(CanUseHandledHintsFromAncestors(mOwner));
// We allow aParent.mOwner to be null, for cases when we're not starting at
// the root of the tree. We also allow aParent.mOwner to be somewhere up our
// expected owner chain not our immediate owner, which allows us creating long
// chains of ServoRestyleStates in some cases where it's just not worth it.
if (aParent.mOwner) {
const nsIFrame* owner = ExpectedOwnerForChild(mOwner);
if (owner != aParent.mOwner && !IsInReplicatedFixedPosTree(mOwner)) {
MOZ_ASSERT(IsAnonBox(owner),
"Should only have expected owner weirdness when anon boxes "
"are involved");
bool found = false;
for (; owner; owner = ExpectedOwnerForChild(owner)) {
if (owner == aParent.mOwner) {
found = true;
break;
}
}
MOZ_ASSERT(found, "Must have aParent.mOwner on our expected owner chain");
}
}
}
nsChangeHint ServoRestyleState::ChangesHandledFor(
const nsIFrame* aFrame) const {
if (!mOwner) {
MOZ_ASSERT(!mChangesHandled);
return mChangesHandled;
}
MOZ_ASSERT(mOwner == ExpectedOwnerForChild(aFrame) ||
IsInReplicatedFixedPosTree(aFrame),
"Missed some frame in the hierarchy?");
return mChangesHandled;
}
#endif
void ServoRestyleState::AddPendingWrapperRestyle(nsIFrame* aWrapperFrame) {
MOZ_ASSERT(aWrapperFrame->Style()->IsWrapperAnonBox(),
"All our wrappers are anon boxes, and why would we restyle "
"non-inheriting ones?");
MOZ_ASSERT(aWrapperFrame->Style()->IsInheritingAnonBox(),
"All our wrappers are anon boxes, and why would we restyle "
"non-inheriting ones?");
MOZ_ASSERT(
aWrapperFrame->Style()->GetPseudoType() != PseudoStyleType::cellContent,
"Someone should be using TableAwareParentFor");
MOZ_ASSERT(
aWrapperFrame->Style()->GetPseudoType() != PseudoStyleType::tableWrapper,
"Someone should be using TableAwareParentFor");
// Make sure we only add first continuations.
aWrapperFrame = aWrapperFrame->FirstContinuation();
nsIFrame* last = mPendingWrapperRestyles.SafeLastElement(nullptr);
if (last == aWrapperFrame) {
// Already queued up, nothing to do.
return;
}
// Make sure to queue up parents before children. But don't queue up
// ancestors of non-anonymous boxes here; those are handled when we traverse
// their non-anonymous kids.
if (aWrapperFrame->ParentIsWrapperAnonBox()) {
AddPendingWrapperRestyle(TableAwareParentFor(aWrapperFrame));
}
// If the append fails, we'll fail to restyle properly, but that's probably
// better than crashing.
if (mPendingWrapperRestyles.AppendElement(aWrapperFrame, fallible)) {
aWrapperFrame->SetIsWrapperAnonBoxNeedingRestyle(true);
}
}
void ServoRestyleState::ProcessWrapperRestyles(nsIFrame* aParentFrame) {
size_t i = mPendingWrapperRestyleOffset;
while (i < mPendingWrapperRestyles.Length()) {
i += ProcessMaybeNestedWrapperRestyle(aParentFrame, i);
}
mPendingWrapperRestyles.TruncateLength(mPendingWrapperRestyleOffset);
}
size_t ServoRestyleState::ProcessMaybeNestedWrapperRestyle(nsIFrame* aParent,
size_t aIndex) {
// The frame at index aIndex is something we should restyle ourselves, but
// following frames may need separate ServoRestyleStates to restyle.
MOZ_ASSERT(aIndex < mPendingWrapperRestyles.Length());
nsIFrame* cur = mPendingWrapperRestyles[aIndex];
MOZ_ASSERT(cur->Style()->IsWrapperAnonBox());
// Where is cur supposed to inherit from? From its parent frame, except in
// the case when cur is a table, in which case it should be its grandparent.
// Also, not in the case when the resulting frame would be a first-line; in
// that case we should be inheriting from the block, and the first-line will
// do its fixup later if needed.
//
// Note that after we do all that fixup the parent we get might still not be
// aParent; for example aParent could be a scrollframe, in which case we
// should inherit from the scrollcontent frame. Or the parent might be some
// continuation of aParent.
//
// Try to assert as much as we can about the parent we actually end up using
// without triggering bogus asserts in all those various edge cases.
nsIFrame* parent = cur->GetParent();
if (cur->IsTableFrame()) {
MOZ_ASSERT(parent->IsTableWrapperFrame());
parent = parent->GetParent();
}
if (parent->IsLineFrame()) {
parent = parent->GetParent();
}
MOZ_ASSERT(FirstContinuationOrPartOfIBSplit(parent) == aParent ||
(parent->Style()->IsInheritingAnonBox() &&
parent->GetContent() == aParent->GetContent()));
// Now "this" is a ServoRestyleState for aParent, so if parent is not a next
// continuation (possibly across ib splits) of aParent we need a new
// ServoRestyleState for the kid.
Maybe<ServoRestyleState> parentRestyleState;
nsIFrame* parentForRestyle =
nsLayoutUtils::FirstContinuationOrIBSplitSibling(parent);
if (parentForRestyle != aParent) {
parentRestyleState.emplace(*parentForRestyle, *this, nsChangeHint_Empty,
CanUseHandledHints::Yes);
}
ServoRestyleState& curRestyleState =
parentRestyleState ? *parentRestyleState : *this;
// This frame may already have been restyled. Even if it has, we can't just
// return, because the next frame may be a kid of it that does need restyling.
if (cur->IsWrapperAnonBoxNeedingRestyle()) {
parentForRestyle->UpdateStyleOfChildAnonBox(cur, curRestyleState);
cur->SetIsWrapperAnonBoxNeedingRestyle(false);
}
size_t numProcessed = 1;
// Note: no overflow possible here, since aIndex < length.
if (aIndex + 1 < mPendingWrapperRestyles.Length()) {
nsIFrame* next = mPendingWrapperRestyles[aIndex + 1];
if (TableAwareParentFor(next) == cur &&
next->IsWrapperAnonBoxNeedingRestyle()) {
// It might be nice if we could do better than nsChangeHint_Empty. On
// the other hand, presumably our mChangesHandled already has the bits
// we really want here so in practice it doesn't matter.
ServoRestyleState childState(*cur, curRestyleState, nsChangeHint_Empty,
CanUseHandledHints::Yes,
/* aAssertWrapperRestyleLength = */ false);
numProcessed +=
childState.ProcessMaybeNestedWrapperRestyle(cur, aIndex + 1);
}
}
return numProcessed;
}
nsIFrame* ServoRestyleState::TableAwareParentFor(const nsIFrame* aChild) {
// We want to get the anon box parent for aChild. where aChild has
// ParentIsWrapperAnonBox().
//
// For the most part this is pretty straightforward, but there are two
// wrinkles. First, if aChild is a table, then we really want the parent of
// its table wrapper.
if (aChild->IsTableFrame()) {
aChild = aChild->GetParent();
MOZ_ASSERT(aChild->IsTableWrapperFrame());
}
nsIFrame* parent = aChild->GetParent();
// Now if parent is a cell-content frame, we actually want the cellframe.
if (parent->Style()->GetPseudoType() == PseudoStyleType::cellContent) {
parent = parent->GetParent();
} else if (parent->IsTableWrapperFrame()) {
// Must be a caption. In that case we want the table here.
MOZ_ASSERT(aChild->StyleDisplay()->mDisplay == StyleDisplay::TableCaption);
parent = parent->PrincipalChildList().FirstChild();
}
return parent;
}
void RestyleManager::PostRestyleEvent(Element* aElement,
RestyleHint 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 && !aMinChangeHint) {
// FIXME(emilio): we should assert against this instead.
return; // Nothing to do.
}
// Assuming the restyle hints will invalidate cached style for
// getComputedStyle, since we don't know if any of the restyling that we do
// would affect undisplayed elements.
if (aRestyleHint) {
if (!(aRestyleHint & RestyleHint::ForAnimations())) {
mHaveNonAnimationRestyles = true;
}
IncrementUndisplayedRestyleGeneration();
}
// 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 || aMinChangeHint) {
Servo_NoteExplicitHints(aElement, aRestyleHint, aMinChangeHint);
}
}
void RestyleManager::PostRestyleEventForAnimations(Element* aElement,
PseudoStyleType aPseudoType,
RestyleHint aRestyleHint) {
Element* elementToRestyle =
AnimationUtils::GetElementForRestyle(aElement, aPseudoType);
if (!elementToRestyle) {
// EffectCompositor::mElementsToRestyle still has unbound old pseudo
// element. We should drop it.
return;
}
mPresContext->TriggeredAnimationRestyle();
Servo_NoteExplicitHints(elementToRestyle, aRestyleHint, nsChangeHint(0));
}
void RestyleManager::RebuildAllStyleData(nsChangeHint aExtraHint,
RestyleHint aRestyleHint) {
// NOTE(emilio): The semantics of these methods are quite funny, in the sense
// that we're not supposed to need to rebuild the actual stylist data.
//
// That's handled as part of the MediumFeaturesChanged stuff, if needed.
//
// Clear the cached style data only if we are guaranteed to process the whole
// DOM tree again.
//
// FIXME(emilio): Decouple this, probably. This probably just wants to reset
// the "uses viewport units / uses rem" bits, and _maybe_ clear cached anon
// box styles and such... But it doesn't really always need to clear the
// initial style of the document and similar...
if (aRestyleHint.DefinitelyRecascadesAllSubtree()) {
StyleSet()->ClearCachedStyleData();
}
DocumentStyleRootIterator iter(mPresContext->Document());
while (Element* root = iter.GetNextStyleRoot()) {
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 RestyleManager::ClearServoDataFromSubtree(Element* aElement,
IncludeRoot aIncludeRoot) {
if (aElement->HasServoData()) {
StyleChildrenIterator it(aElement);
for (nsIContent* n = it.GetNextChild(); n; n = it.GetNextChild()) {
if (n->IsElement()) {
ClearServoDataFromSubtree(n->AsElement(), IncludeRoot::Yes);
}
}
}
if (MOZ_LIKELY(aIncludeRoot == IncludeRoot::Yes)) {
aElement->ClearServoData();
MOZ_ASSERT(!aElement->HasAnyOfFlags(Element::kAllServoDescendantBits |
NODE_NEEDS_FRAME));
MOZ_ASSERT(aElement != aElement->OwnerDoc()->GetServoRestyleRoot());
}
}
/* static */
void RestyleManager::ClearRestyleStateFromSubtree(Element* aElement) {
if (aElement->HasAnyOfFlags(Element::kAllServoDescendantBits)) {
StyleChildrenIterator it(aElement);
for (nsIContent* n = it.GetNextChild(); n; n = it.GetNextChild()) {
if (n->IsElement()) {
ClearRestyleStateFromSubtree(n->AsElement());
}
}
}
bool wasRestyled = false;
Unused << Servo_TakeChangeHint(aElement, &wasRestyled);
aElement->UnsetFlags(Element::kAllServoDescendantBits);
}
/**
* 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 RestyleManager::TextPostTraversalState {
public:
TextPostTraversalState(Element& aParentElement, ComputedStyle* aParentContext,
bool aDisplayContentsParentStyleChanged,
ServoRestyleState& aParentRestyleState)
: mParentElement(aParentElement),
mParentContext(aParentContext),
mParentRestyleState(aParentRestyleState),
mStyle(nullptr),
mShouldPostHints(aDisplayContentsParentStyleChanged),
mShouldComputeHints(aDisplayContentsParentStyleChanged),
mComputedHint(nsChangeHint_Empty) {}
nsStyleChangeList& ChangeList() { return mParentRestyleState.ChangeList(); }
ComputedStyle& ComputeStyle(nsIContent* aTextNode) {
if (!mStyle) {
mStyle = mParentRestyleState.StyleSet().ResolveStyleForText(
aTextNode, &ParentStyle());
}
MOZ_ASSERT(mStyle);
return *mStyle;
}
void ComputeHintIfNeeded(nsIContent* aContent, nsIFrame* aTextFrame,
ComputedStyle& aNewStyle) {
MOZ_ASSERT(aTextFrame);
MOZ_ASSERT(aNewStyle.GetPseudoType() == PseudoStyleType::mozText);
if (MOZ_LIKELY(!mShouldPostHints)) {
return;
}
ComputedStyle* oldStyle = aTextFrame->Style();
MOZ_ASSERT(oldStyle->GetPseudoType() == PseudoStyleType::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;
mComputedHint = oldStyle->CalcStyleDifference(aNewStyle, &equalStructs);
mComputedHint = NS_RemoveSubsumedHints(
mComputedHint, mParentRestyleState.ChangesHandledFor(aTextFrame));
}
if (mComputedHint) {
mParentRestyleState.ChangeList().AppendChange(aTextFrame, aContent,
mComputedHint);
}
}
private:
ComputedStyle& ParentStyle() {
if (!mParentContext) {
mLazilyResolvedParentContext =
ServoStyleSet::ResolveServoStyle(mParentElement);
mParentContext = mLazilyResolvedParentContext;
}
return *mParentContext;
}
Element& mParentElement;
ComputedStyle* mParentContext;
RefPtr<ComputedStyle> mLazilyResolvedParentContext;
ServoRestyleState& mParentRestyleState;
RefPtr<ComputedStyle> mStyle;
bool mShouldPostHints;
bool mShouldComputeHints;
nsChangeHint mComputedHint;
};
static void UpdateBackdropIfNeeded(nsIFrame* aFrame, ServoStyleSet& aStyleSet,
nsStyleChangeList& aChangeList) {
const nsStyleDisplay* display = aFrame->Style()->StyleDisplay();
if (display->mTopLayer != StyleTopLayer::Top) {
return;
}
// Elements in the top layer are guaranteed to have absolute or fixed
MOZ_ASSERT(display->IsAbsolutelyPositionedStyle());
nsIFrame* backdropPlaceholder =
aFrame->GetChildList(FrameChildListID::Backdrop).FirstChild();
if (!backdropPlaceholder) {
return;
}
MOZ_ASSERT(backdropPlaceholder->IsPlaceholderFrame());
nsIFrame* backdropFrame =
nsPlaceholderFrame::GetRealFrameForPlaceholder(backdropPlaceholder);
MOZ_ASSERT(backdropFrame->IsBackdropFrame());
MOZ_ASSERT(backdropFrame->Style()->GetPseudoType() ==
PseudoStyleType::backdrop);
RefPtr<ComputedStyle> newStyle = aStyleSet.ResolvePseudoElementStyle(
*aFrame->GetContent()->AsElement(), PseudoStyleType::backdrop, nullptr,
aFrame->Style());
// NOTE(emilio): We can't use the changes handled for the owner of the
// backdrop frame, since it's out of flow, and parented to the viewport or
// canvas frame (depending on the `position` value).
MOZ_ASSERT(backdropFrame->GetParent()->IsViewportFrame() ||
backdropFrame->GetParent()->IsCanvasFrame());
nsTArray<nsIFrame*> wrappersToRestyle;
nsTArray<RefPtr<Element>> anchorsToSuppress;
ServoRestyleState state(aStyleSet, aChangeList, wrappersToRestyle,
anchorsToSuppress);
nsIFrame::UpdateStyleOfOwnedChildFrame(backdropFrame, newStyle, state);
MOZ_ASSERT(anchorsToSuppress.IsEmpty());
}
static void UpdateFirstLetterIfNeeded(nsIFrame* aFrame,
ServoRestyleState& aRestyleState) {
MOZ_ASSERT(
!aFrame->IsBlockFrameOrSubclass(),
"You're probably duplicating work with UpdatePseudoElementStyles!");
if (!aFrame->HasFirstLetterChild()) {
return;
}
// We need to find the block the first-letter is associated with so we can
// find the right element for the first-letter's style resolution. Might as
// well just delegate the whole thing to that block.
nsIFrame* block = aFrame->GetParent();
while (!block->IsBlockFrameOrSubclass()) {
block = block->GetParent();
}
static_cast<nsBlockFrame*>(block->FirstContinuation())
->UpdateFirstLetterStyle(aRestyleState);
}
static void UpdateOneAdditionalComputedStyle(nsIFrame* aFrame, uint32_t aIndex,
ComputedStyle& aOldContext,
ServoRestyleState& aRestyleState) {
auto pseudoType = aOldContext.GetPseudoType();
MOZ_ASSERT(pseudoType != PseudoStyleType::NotPseudo);
MOZ_ASSERT(
!nsCSSPseudoElements::PseudoElementSupportsUserActionState(pseudoType));
RefPtr<ComputedStyle> newStyle =
aRestyleState.StyleSet().ResolvePseudoElementStyle(
*aFrame->GetContent()->AsElement(), pseudoType, nullptr,
aFrame->Style());
uint32_t equalStructs; // Not used, actually.
nsChangeHint childHint =
aOldContext.CalcStyleDifference(*newStyle, &equalStructs);
if (CanUseHandledHintsFromAncestors(aFrame)) {
childHint = NS_RemoveSubsumedHints(childHint,
aRestyleState.ChangesHandledFor(aFrame));
}
if (childHint) {
if (childHint & nsChangeHint_ReconstructFrame) {
// If we generate a reconstruct here, remove any non-reconstruct hints we
// may have already generated for this content.
aRestyleState.ChangeList().PopChangesForContent(aFrame->GetContent());
}
aRestyleState.ChangeList().AppendChange(aFrame, aFrame->GetContent(),
childHint);
}
aFrame->SetAdditionalComputedStyle(aIndex, newStyle);
}
static void UpdateAdditionalComputedStyles(nsIFrame* aFrame,
ServoRestyleState& aRestyleState) {
MOZ_ASSERT(aFrame);
MOZ_ASSERT(aFrame->GetContent() && aFrame->GetContent()->IsElement());
// FIXME(emilio): Consider adding a bit or something to avoid the initial
// virtual call?
uint32_t index = 0;
while (auto* oldStyle = aFrame->GetAdditionalComputedStyle(index)) {
UpdateOneAdditionalComputedStyle(aFrame, index++, *oldStyle, aRestyleState);
}
}
static void UpdateFramePseudoElementStyles(nsIFrame* aFrame,
ServoRestyleState& aRestyleState) {
if (nsBlockFrame* blockFrame = do_QueryFrame(aFrame)) {
blockFrame->UpdatePseudoElementStyles(aRestyleState);
} else {
UpdateFirstLetterIfNeeded(aFrame, aRestyleState);
}
UpdateBackdropIfNeeded(aFrame, aRestyleState.StyleSet(),
aRestyleState.ChangeList());
}
enum class ServoPostTraversalFlags : uint32_t {
Empty = 0,
// Whether parent was restyled.
ParentWasRestyled = 1 << 0,
// Skip sending accessibility notifications for all descendants.
SkipA11yNotifications = 1 << 1,
// Always send accessibility notifications if the element is shown.
// The SkipA11yNotifications flag above overrides this flag.
SendA11yNotificationsIfShown = 1 << 2,
};
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(ServoPostTraversalFlags)
#ifdef ACCESSIBILITY
static bool IsVisibleForA11y(const ComputedStyle& aStyle) {
return aStyle.StyleVisibility()->IsVisible() && !aStyle.StyleUI()->IsInert();
}
static bool IsSubtreeVisibleForA11y(const ComputedStyle& aStyle) {
return aStyle.StyleDisplay()->mContentVisibility !=
StyleContentVisibility::Hidden;
}
#endif
// Send proper accessibility notifications and return post traversal
// flags for kids.
static ServoPostTraversalFlags SendA11yNotifications(
nsPresContext* aPresContext, Element* aElement,
const ComputedStyle& aOldStyle, const ComputedStyle& aNewStyle,
ServoPostTraversalFlags aFlags) {
using Flags = ServoPostTraversalFlags;
MOZ_ASSERT(!(aFlags & Flags::SkipA11yNotifications) ||
!(aFlags & Flags::SendA11yNotificationsIfShown),
"The two a11y flags should never be set together");
#ifdef ACCESSIBILITY
nsAccessibilityService* accService = GetAccService();
if (!accService) {
// If we don't have accessibility service, accessibility is not
// enabled. Just skip everything.
return Flags::Empty;
}
if (aNewStyle.StyleUIReset()->mMozSubtreeHiddenOnlyVisually !=
aOldStyle.StyleUIReset()->mMozSubtreeHiddenOnlyVisually) {
if (aElement->GetParent() &&
aElement->GetParent()->IsXULElement(nsGkAtoms::tabpanels)) {
accService->NotifyOfTabPanelVisibilityChange(
aPresContext->PresShell(), aElement,
aNewStyle.StyleUIReset()->mMozSubtreeHiddenOnlyVisually);
}
}
if (aFlags & Flags::SkipA11yNotifications) {
// Propagate the skipping flag to descendants.
return Flags::SkipA11yNotifications;
}
bool needsNotify = false;
const bool isVisible = IsVisibleForA11y(aNewStyle);
const bool wasVisible = IsVisibleForA11y(aOldStyle);
if (aFlags & Flags::SendA11yNotificationsIfShown) {
if (!isVisible) {
// Propagate the sending-if-shown flag to descendants.
return Flags::SendA11yNotificationsIfShown;
}
// We have asked accessibility service to remove the whole subtree
// of element which becomes invisible from the accessible tree, but
// this element is visible, so we need to add it back.
needsNotify = true;
} else {
// If we shouldn't skip in any case, we need to check whether our own
// visibility has changed.
// Also notify if the subtree visibility change due to content-visibility.
const bool isSubtreeVisible = IsSubtreeVisibleForA11y(aNewStyle);
const bool wasSubtreeVisible = IsSubtreeVisibleForA11y(aOldStyle);
needsNotify =
wasVisible != isVisible || wasSubtreeVisible != isSubtreeVisible;
}
if (needsNotify) {
PresShell* presShell = aPresContext->PresShell();
if (isVisible) {
accService->ContentRangeInserted(presShell, aElement,
aElement->GetNextSibling());
// We are adding the subtree. Accessibility service would handle
// descendants, so we should just skip them from notifying.
return Flags::SkipA11yNotifications;
}
if (wasVisible) {
// Remove the subtree of this invisible element, and ask any shown
// descendant to add themselves back.
accService->ContentRemoved(presShell, aElement);
return Flags::SendA11yNotificationsIfShown;
}
}
#endif
return Flags::Empty;
}
bool RestyleManager::ProcessPostTraversal(Element* aElement,
ServoRestyleState& aRestyleState,
ServoPostTraversalFlags aFlags) {
nsIFrame* styleFrame = nsLayoutUtils::GetStyleFrame(aElement);
nsIFrame* primaryFrame = aElement->GetPrimaryFrame();
MOZ_DIAGNOSTIC_ASSERT(aElement->HasServoData(),
"Element without Servo data on a post-traversal? How?");
// NOTE(emilio): This is needed because for table frames the bit is set on the
// table wrapper (which is the primary frame), not on the table itself.
const bool isOutOfFlow =
primaryFrame && primaryFrame->HasAnyStateBits(NS_FRAME_OUT_OF_FLOW);
const bool canUseHandledHints =
primaryFrame && CanUseHandledHintsFromAncestors(primaryFrame);
// Grab the change hint from Servo.
bool wasRestyled = false;
nsChangeHint changeHint =
static_cast<nsChangeHint>(Servo_TakeChangeHint(aElement, &wasRestyled));
RefPtr<ComputedStyle> upToDateStyleIfRestyled =
wasRestyled ? ServoStyleSet::ResolveServoStyle(*aElement) : nullptr;
// We should really fix the weird primary frame mapping for image maps
if (styleFrame && styleFrame->GetContent() != aElement) {
MOZ_ASSERT(styleFrame->IsImageFrameOrSubclass());
styleFrame = nullptr;
}
// Handle lazy frame construction by posting a reconstruct for any lazily-
// constructed roots.
if (aElement->HasFlag(NODE_NEEDS_FRAME)) {
changeHint |= nsChangeHint_ReconstructFrame;
MOZ_ASSERT(!styleFrame);
}
if (styleFrame) {
MOZ_ASSERT(primaryFrame);
nsIFrame* maybeAnonBoxChild;
if (isOutOfFlow) {
maybeAnonBoxChild = primaryFrame->GetPlaceholderFrame();
} else {
maybeAnonBoxChild = primaryFrame;
}
// Do not subsume change hints for the column-spanner.
if (canUseHandledHints) {
changeHint = NS_RemoveSubsumedHints(
changeHint, aRestyleState.ChangesHandledFor(styleFrame));
}
// If the parent wasn't restyled, the styles of our anon box parents won't
// change either.
if ((aFlags & ServoPostTraversalFlags::ParentWasRestyled) &&
maybeAnonBoxChild->ParentIsWrapperAnonBox()) {
aRestyleState.AddPendingWrapperRestyle(
ServoRestyleState::TableAwareParentFor(maybeAnonBoxChild));
}
// If we don't have a ::marker pseudo-element, but need it, then
// reconstruct the frame. (The opposite situation implies 'display'
// changes so doesn't need to be handled explicitly here.)
if (wasRestyled && styleFrame->StyleDisplay()->IsListItem() &&
styleFrame->IsBlockFrameOrSubclass() &&
!nsLayoutUtils::GetMarkerPseudo(aElement)) {
RefPtr<ComputedStyle> pseudoStyle =
aRestyleState.StyleSet().ProbePseudoElementStyle(
*aElement, PseudoStyleType::marker, nullptr,
upToDateStyleIfRestyled);
if (pseudoStyle) {
changeHint |= nsChangeHint_ReconstructFrame;
}
}
}
// 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) {
aRestyleState.ChangeList().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) {
if (wasRestyled &&
StaticPrefs::layout_css_scroll_anchoring_suppressions_enabled()) {
const bool wasAbsPos =
styleFrame &&
styleFrame->StyleDisplay()->IsAbsolutelyPositionedStyle();
auto* newDisp = upToDateStyleIfRestyled->StyleDisplay();
//
// We need to do the position check here rather than in
// DidSetComputedStyle because changing position reframes.
//
// We suppress adjustments whenever we change from being display: none to
// be an abspos.
//
// Similarly, for other changes from abspos to non-abspos styles.
//
// TODO(emilio): I _think_ chrome won't suppress adjustments whenever
// `display` changes. But that causes some infinite loops in cases like
if (wasAbsPos != newDisp->IsAbsolutelyPositionedStyle()) {
aRestyleState.AddPendingScrollAnchorSuppression(aElement);
}
}
ClearRestyleStateFromSubtree(aElement);
return true;
}
// TODO(emilio): We could avoid some refcount traffic here, specially in the
// ComputedStyle case, which uses atomic refcounting.
//
// Hold the ComputedStyle alive, because it could become a dangling pointer
// during the replacement. In practice it's not a huge deal, but better not
// playing with dangling pointers if not needed.
//
// NOTE(emilio): We could keep around the old computed style for display:
// contents elements too, but we don't really need it right now.
RefPtr<ComputedStyle> oldOrDisplayContentsStyle =
styleFrame ? styleFrame->Style() : nullptr;
MOZ_ASSERT(!(styleFrame && Servo_Element_IsDisplayContents(aElement)),
"display: contents node has a frame, yet we didn't reframe it"
" above?");
const bool isDisplayContents = !styleFrame && aElement->HasServoData() &&
Servo_Element_IsDisplayContents(aElement);
if (isDisplayContents) {
oldOrDisplayContentsStyle = ServoStyleSet::ResolveServoStyle(*aElement);
}
Maybe<ServoRestyleState> thisFrameRestyleState;
if (styleFrame) {
thisFrameRestyleState.emplace(
*styleFrame, aRestyleState, changeHint,
ServoRestyleState::CanUseHandledHints(canUseHandledHints));
}
// We can't really assume as used changes from display: contents elements (or
// other elements without frames).
ServoRestyleState& childrenRestyleState =
thisFrameRestyleState ? *thisFrameRestyleState : aRestyleState;
ComputedStyle* upToDateStyle =
wasRestyled ? upToDateStyleIfRestyled : oldOrDisplayContentsStyle;
ServoPostTraversalFlags childrenFlags =
wasRestyled ? ServoPostTraversalFlags::ParentWasRestyled
: ServoPostTraversalFlags::Empty;
if (wasRestyled && oldOrDisplayContentsStyle) {
MOZ_ASSERT(styleFrame || isDisplayContents);
// We want to walk all the continuations here, even the ones with different
// styles. In practice, the only reason we get continuations with different
// styles here is ::first-line (::first-letter never affects element
// styles). But in that case, newStyle is the right context for the
// _later_ continuations anyway (the ones not affected by ::first-line), not
// the earlier ones, so there is no point stopping right at the point when
// we'd actually be setting the right ComputedStyle.
//
// This does mean that we may be setting the wrong ComputedStyle on our
// initial continuations; ::first-line fixes that up after the fact.
for (nsIFrame* f = styleFrame; f; f = f->GetNextContinuation()) {
MOZ_ASSERT_IF(f != styleFrame, !f->GetAdditionalComputedStyle(0));
f->SetComputedStyle(upToDateStyle);
}
if (styleFrame) {
UpdateAdditionalComputedStyles(styleFrame, aRestyleState);
}
if (!aElement->GetParent()) {
// This is the root. Update styles on the viewport as needed.
ViewportFrame* viewport =
do_QueryFrame(mPresContext->PresShell()->GetRootFrame());
if (viewport) {
// NB: The root restyle state, not the one for our children!
viewport->UpdateStyle(aRestyleState);
}
}
// 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 |newStyle| to
// |styleFrame| to ensure the animated transform has been removed first.
AddLayerChangesForAnimation(styleFrame, primaryFrame, aElement, changeHint,
aRestyleState.ChangeList());
childrenFlags |= SendA11yNotifications(mPresContext, aElement,
*oldOrDisplayContentsStyle,
*upToDateStyle, aFlags);
}
const bool traverseElementChildren =
aElement->HasAnyOfFlags(Element::kAllServoDescendantBits);
const bool traverseTextChildren =
wasRestyled || aElement->HasFlag(NODE_DESCENDANTS_NEED_FRAMES);
bool recreatedAnyContext = wasRestyled;
if (traverseElementChildren || traverseTextChildren) {
StyleChildrenIterator it(aElement);
TextPostTraversalState textState(*aElement, upToDateStyle,
isDisplayContents && wasRestyled,
childrenRestyleState);
for (nsIContent* n = it.GetNextChild(); n; n = it.GetNextChild()) {
if (traverseElementChildren && n->IsElement()) {
recreatedAnyContext |= ProcessPostTraversal(
n->AsElement(), childrenRestyleState, childrenFlags);
} else if (traverseTextChildren && n->IsText()) {
recreatedAnyContext |= ProcessPostTraversalForText(
n, textState, childrenRestyleState, childrenFlags);
}
}
}
// We want to update frame pseudo-element styles after we've traversed our
// kids, because some of those updates (::first-line/::first-letter) need to
// modify the styles of the kids, and the child traversal above would just
// clobber those modifications.
if (styleFrame) {
if (wasRestyled) {
// Make sure to update anon boxes and pseudo bits after updating text,
// otherwise ProcessPostTraversalForText could clobber first-letter
// styles, for example.
styleFrame->UpdateStyleOfOwnedAnonBoxes(childrenRestyleState);
}
// Process anon box wrapper frames before ::first-line bits, but _after_
// owned anon boxes, since the children wrapper anon boxes could be
// inheriting from our own owned anon boxes.
childrenRestyleState.ProcessWrapperRestyles(styleFrame);
if (wasRestyled) {
UpdateFramePseudoElementStyles(styleFrame, childrenRestyleState);
} else if (traverseElementChildren &&
styleFrame->IsBlockFrameOrSubclass()) {
// Even if we were not restyled, if we're a block with a first-line and
// one of our descendant elements which is on the first line was restyled,
// we need to update the styles of things on the first line, because
// they're wrong now.
//
// FIXME(bz) Could we do better here? For example, could we keep track of
// frames that are "block with a ::first-line so we could avoid
// IsFrameOfType() and digging about for the first-line frame if not?
// Could we keep track of whether the element children we actually restyle
// this better.
nsIFrame* firstLineFrame =
static_cast<nsBlockFrame*>(styleFrame)->GetFirstLineFrame();
if (firstLineFrame) {
for (nsIFrame* kid : firstLineFrame->PrincipalChildList()) {
ReparentComputedStyleForFirstLine(kid);
}
}
}
}
aElement->UnsetFlags(Element::kAllServoDescendantBits);
return recreatedAnyContext;
}
bool RestyleManager::ProcessPostTraversalForText(
nsIContent* aTextNode, TextPostTraversalState& aPostTraversalState,
ServoRestyleState& aRestyleState, ServoPostTraversalFlags aFlags) {
// Handle lazy frame construction.
if (aTextNode->HasFlag(NODE_NEEDS_FRAME)) {
aPostTraversalState.ChangeList().AppendChange(
nullptr, aTextNode, nsChangeHint_ReconstructFrame);
return true;
}
// Handle restyle.
nsIFrame* primaryFrame = aTextNode->GetPrimaryFrame();
if (!primaryFrame) {
return false;
}
// If the parent wasn't restyled, the styles of our anon box parents won't
// change either.
if ((aFlags & ServoPostTraversalFlags::ParentWasRestyled) &&
primaryFrame->ParentIsWrapperAnonBox()) {
aRestyleState.AddPendingWrapperRestyle(
ServoRestyleState::TableAwareParentFor(primaryFrame));
}
ComputedStyle& newStyle = aPostTraversalState.ComputeStyle(aTextNode);
aPostTraversalState.ComputeHintIfNeeded(aTextNode, primaryFrame, newStyle);
// We want to walk all the continuations here, even the ones with different
// styles. In practice, the only reasons we get continuations with different
// styles are ::first-line and ::first-letter. But in those cases,
// newStyle is the right context for the _later_ continuations anyway (the
// ones not affected by ::first-line/::first-letter), not the earlier ones,
// so there is no point stopping right at the point when we'd actually be
// setting the right ComputedStyle.
//
// This does mean that we may be setting the wrong ComputedStyle on our
// initial continuations; ::first-line/::first-letter fix that up after the
// fact.
for (nsIFrame* f = primaryFrame; f; f = f->GetNextContinuation()) {
f->SetComputedStyle(&newStyle);
}
return true;
}
void RestyleManager::ClearSnapshots() {
for (auto iter = mSnapshots.Iter(); !iter.Done(); iter.Next()) {
iter.Key()->UnsetFlags(ELEMENT_HAS_SNAPSHOT | ELEMENT_HANDLED_SNAPSHOT);
iter.Remove();
}
}
ServoElementSnapshot& RestyleManager::SnapshotFor(Element& aElement) {
MOZ_DIAGNOSTIC_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.HasFlag(ELEMENT_HANDLED_SNAPSHOT));
ServoElementSnapshot* snapshot =
mSnapshots.GetOrInsertNew(&aElement, aElement);
aElement.SetFlags(ELEMENT_HAS_SNAPSHOT);
// Now that we have a snapshot, make sure a restyle is triggered.
aElement.NoteDirtyForServo();
return *snapshot;
}
void RestyleManager::DoProcessPendingRestyles(ServoTraversalFlags aFlags) {
nsPresContext* presContext = PresContext();
PresShell* presShell = presContext->PresShell();
MOZ_ASSERT(presContext->Document(), "No document? Pshaw!");
// FIXME(emilio): In the "flush animations" case, ideally, we should only
// recascade animation styles running on the compositor, so we shouldn't care
// about other styles, or new rules that apply to the page...
//
MOZ_ASSERT((aFlags & ServoTraversalFlags::FlushThrottledAnimations) ||
!presContext->HasPendingMediaQueryUpdates(),
"Someone forgot to update media queries?");
MOZ_ASSERT(!nsContentUtils::IsSafeToRunScript(), "Missing a script blocker!");
MOZ_RELEASE_ASSERT(!mInStyleRefresh, "Reentrant call?");
if (MOZ_UNLIKELY(!presShell->DidInitialize())) {
// PresShell::FlushPendingNotifications doesn't early-return in the case
// where the PresShell 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;
}
// It'd be bad!
PresShell::AutoAssertNoFlush noReentrantFlush(*presShell);
// 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();
Document* doc = presContext->Document();
// Ensure the refresh driver is active during traversal to avoid mutating
// mActiveTimer and mMostRecentRefresh time.
presContext->RefreshDriver()->MostRecentRefresh();
if (!doc->GetServoRestyleRoot()) {
// This might post new restyles, so need to do it here. Don't do it if we're
// already going to restyle tho, so that we don't potentially reflow with
// dirty styling.
presContext->UpdateContainerQueryStyles();
presContext->FinishedContainerQueryUpdate();
}
// Perform the Servo traversal, and the post-traversal if required. We do this
// in a loop because certain rare paths in the frame constructor can trigger
// additional style invalidations.
//
// FIXME(emilio): Confirm whether that's still true now that XBL is gone.
mInStyleRefresh = true;
if (mHaveNonAnimationRestyles) {
++mAnimationGeneration;
}
if (mRestyleForCSSRuleChanges) {
aFlags |= ServoTraversalFlags::ForCSSRuleChanges;
}
while (styleSet->StyleDocument(aFlags)) {
ClearSnapshots();
// Select scroll anchors for frames that have been scrolled. Do this
// before processing restyled frames so that anchor nodes are correctly
// marked when directly moving frames with RecomputePosition.
presContext->PresShell()->FlushPendingScrollAnchorSelections();
nsStyleChangeList currentChanges;
bool anyStyleChanged = false;
// Recreate styles , and queue up change hints (which also handle lazy frame
// construction).
nsTArray<RefPtr<Element>> anchorsToSuppress;
{
DocumentStyleRootIterator iter(doc->GetServoRestyleRoot());
while (Element* root = iter.GetNextStyleRoot()) {
nsTArray<nsIFrame*> wrappersToRestyle;
ServoRestyleState state(*styleSet, currentChanges, wrappersToRestyle,
anchorsToSuppress);
ServoPostTraversalFlags flags = ServoPostTraversalFlags::Empty;
anyStyleChanged |= ProcessPostTraversal(root, state, flags);
}
// We want to suppress adjustments the current (before-change) scroll
// anchor container now, and save a reference to the content node so that
// we can suppress them in the after-change scroll anchor .
for (Element* element : anchorsToSuppress) {
if (nsIFrame* frame = element->GetPrimaryFrame()) {
if (auto* container = ScrollAnchorContainer::FindFor(frame)) {
container->SuppressAdjustments();
}
}
}
}
doc->ClearServoRestyleRoot();
ClearSnapshots();
// 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
//
// Just ignore those, since we can't really process them.
continue;
}
currentChanges.AppendChange(change.mContent->GetPrimaryFrame(),
change.mContent, change.mHint);
}
newChanges.Clear();
}
mReentrantChanges = nullptr;
}
// Suppress adjustments in the after-change scroll anchors if needed, now
// that we're done reframing everything.
for (Element* element : anchorsToSuppress) {
if (nsIFrame* frame = element->GetPrimaryFrame()) {
if (auto* container = ScrollAnchorContainer::FindFor(frame)) {
container->SuppressAdjustments();
}
}
}
if (anyStyleChanged) {
// Maybe no styles changed when:
//
// * Only explicit change hints were posted in the first place.
// * When an attribute or state change in the content happens not to need
// a restyle after all.
//
// In any case, we don't need to increment the restyle generation in that
// case.
IncrementRestyleGeneration();
}
mInStyleRefresh = false;
presContext->UpdateContainerQueryStyles();
mInStyleRefresh = true;
}
doc->ClearServoRestyleRoot();
presContext->FinishedContainerQueryUpdate();
presContext->UpdateHiddenByContentVisibilityForAnimationsIfNeeded();
ClearSnapshots();
styleSet->AssertTreeIsClean();
mHaveNonAnimationRestyles = false;
mRestyleForCSSRuleChanges = false;
mInStyleRefresh = false;
// Now that everything has settled, see if we have enough free rule nodes in
// the tree to warrant sweeping them.
styleSet->MaybeGCRuleTree();
// Note: We are in the scope of |animationsWithDestroyedFrame|, so
// |mAnimationsWithDestroyedFrame| is still valid.
MOZ_ASSERT(mAnimationsWithDestroyedFrame);
mAnimationsWithDestroyedFrame->StopAnimationsForElementsWithoutFrames();
}
#ifdef DEBUG
static void VerifyFlatTree(const nsIContent& aContent) {
StyleChildrenIterator iter(&aContent);
for (auto* content = iter.GetNextChild(); content;
content = iter.GetNextChild()) {
MOZ_ASSERT(content->GetFlattenedTreeParentNodeForStyle() == &aContent);
VerifyFlatTree(*content);
}
}
#endif
void RestyleManager::ProcessPendingRestyles() {
AUTO_PROFILER_LABEL_RELEVANT_FOR_JS("Styles", LAYOUT);
#ifdef DEBUG
if (auto* root = mPresContext->Document()->GetRootElement()) {
VerifyFlatTree(*root);
}
#endif
DoProcessPendingRestyles(ServoTraversalFlags::Empty);
}
void RestyleManager::ProcessAllPendingAttributeAndStateInvalidations() {
if (mSnapshots.IsEmpty()) {
return;
}
for (const auto& key : mSnapshots.Keys()) {
// Servo data for the element might have been dropped. (e.g. by removing
// from its document)
if (key->HasFlag(ELEMENT_HAS_SNAPSHOT)) {
Servo_ProcessInvalidations(StyleSet()->RawData(), key, &mSnapshots);
}
}
ClearSnapshots();
}
void RestyleManager::UpdateOnlyAnimationStyles() {
bool doCSS = PresContext()->EffectCompositor()->HasPendingStyleUpdates();
if (!doCSS) {
return;
}
DoProcessPendingRestyles(ServoTraversalFlags::FlushThrottledAnimations);
}
void RestyleManager::ElementStateChanged(Element* aElement,
ElementState aChangedBits) {
#ifdef EARLY_BETA_OR_EARLIER
if (MOZ_UNLIKELY(mInStyleRefresh)) {
MOZ_CRASH_UNSAFE_PRINTF(
"Element state change during style refresh (%" PRIu64 ")",
aChangedBits.GetInternalValue());
}
#endif
const ElementState kVisitedAndUnvisited =
ElementState::VISITED | ElementState::UNVISITED;
// We'll restyle when the relevant visited query finishes, regardless of the
// style (see Link::VisitedQueryFinished). So there's no need to do anything
// as a result of this state change just yet.
//
// Note that this check checks for _both_ bits: This is only true when visited
// changes to unvisited or vice-versa, but not when we start or stop being a
// link itself.
if (aChangedBits.HasAllStates(kVisitedAndUnvisited)) {
aChangedBits &= ~kVisitedAndUnvisited;
if (aChangedBits.IsEmpty()) {
return;
}
}
if (auto changeHint = ChangeForContentStateChange(*aElement, aChangedBits)) {
Servo_NoteExplicitHints(aElement, RestyleHint{0}, changeHint);
}
// Don't bother taking a snapshot if no rules depend on these state bits.
//
// We always take a snapshot for the LTR/RTL event states, since Servo doesn't
// track those bits in the same way, and we know that :dir() rules are always
// present in UA style sheets.
if (!aChangedBits.HasAtLeastOneOfStates(ElementState::DIR_STATES) &&
!StyleSet()->HasStateDependency(*aElement, aChangedBits)) {
return;
}
// Assuming we need to invalidate cached style in getComputedStyle for
// undisplayed elements, since we don't know if it is needed.
IncrementUndisplayedRestyleGeneration();
if (!aElement->HasServoData() &&
!(aElement->GetSelectorFlags() &
NodeSelectorFlags::RelativeSelectorSearchDirectionAncestorSibling)) {
return;
}
ServoElementSnapshot& snapshot = SnapshotFor(*aElement);
ElementState previousState = aElement->StyleState() ^ aChangedBits;
snapshot.AddState(previousState);
ServoStyleSet& styleSet = *StyleSet();
MaybeRestyleForNthOfState(styleSet, aElement, aChangedBits);
MaybeRestyleForRelativeSelectorState(styleSet, aElement, aChangedBits);
}
void RestyleManager::CustomStatesWillChange(Element& aElement) {
MOZ_DIAGNOSTIC_ASSERT(!mInStyleRefresh);
IncrementUndisplayedRestyleGeneration();
// Relative selector invalidation travels ancestor and earlier sibling
// direction, so it's very possible that it invalidates a styled element.
if (!aElement.HasServoData() &&
!(aElement.GetSelectorFlags() &
NodeSelectorFlags::RelativeSelectorSearchDirectionAncestorSibling)) {
return;
}
ServoElementSnapshot& snapshot = SnapshotFor(aElement);
snapshot.AddCustomStates(aElement);
}
void RestyleManager::CustomStateChanged(Element& aElement, nsAtom* aState) {
ServoStyleSet& styleSet = *StyleSet();
MaybeRestyleForNthOfCustomState(styleSet, aElement, aState);
styleSet.MaybeInvalidateRelativeSelectorCustomStateDependency(
aElement, aState, Snapshots());
}
void RestyleManager::MaybeRestyleForNthOfCustomState(ServoStyleSet& aStyleSet,
Element& aChild,
nsAtom* aState) {
const auto* parentNode = aChild.GetParentNode();
MOZ_ASSERT(parentNode);
const auto parentFlags = parentNode->GetSelectorFlags();
if (!(parentFlags & NodeSelectorFlags::HasSlowSelectorNthOf)) {
return;
}
if (aStyleSet.HasNthOfCustomStateDependency(aChild, aState)) {
RestyleSiblingsForNthOf(&aChild, parentFlags);
}
}
void RestyleManager::MaybeRestyleForNthOfState(ServoStyleSet& aStyleSet,
Element* aChild,
ElementState aChangedBits) {
const auto* parentNode = aChild->GetParentNode();
MOZ_ASSERT(parentNode);
const auto parentFlags = parentNode->GetSelectorFlags();
if (!(parentFlags & NodeSelectorFlags::HasSlowSelectorNthOf)) {
return;
}
if (aStyleSet.HasNthOfStateDependency(*aChild, aChangedBits)) {
RestyleSiblingsForNthOf(aChild, parentFlags);
}
}
static inline bool AttributeInfluencesOtherPseudoClassState(
const Element& aElement, const nsAtom* aAttribute) {
// We must record some state for :-moz-table-border-nonzero and
// :-moz-select-list-box.
if (aAttribute == nsGkAtoms::border) {
return aElement.IsHTMLElement(nsGkAtoms::table);
}
if (aAttribute == nsGkAtoms::multiple || aAttribute == nsGkAtoms::size) {
return aElement.IsHTMLElement(nsGkAtoms::select);
}
return false;
}
static inline bool NeedToRecordAttrChange(
const ServoStyleSet& aStyleSet, const Element& aElement,
int32_t aNameSpaceID, nsAtom* aAttribute,
bool* aInfluencesOtherPseudoClassState) {
*aInfluencesOtherPseudoClassState =
AttributeInfluencesOtherPseudoClassState(aElement, aAttribute);
// If the attribute influences one of the pseudo-classes that are backed by
// attributes, we just record it.
if (*aInfluencesOtherPseudoClassState) {
return true;
}
// We assume that id and class attributes are used in class/id selectors, and
// thus record them.
//
// TODO(emilio): We keep a filter of the ids in use somewhere in the StyleSet,
// presumably we could try to filter the old and new id, but it's not clear
// it's worth it.
if (aNameSpaceID == kNameSpaceID_None &&
(aAttribute == nsGkAtoms::id || aAttribute == nsGkAtoms::_class)) {
return true;
}
// We always record lang="", even though we force a subtree restyle when it
// changes, since it can change how its siblings match :lang(..) due to
// selectors like :lang(..) + div.
if (aAttribute == nsGkAtoms::lang) {
return true;
}
// Otherwise, just record the attribute change if a selector in the page may
// reference it from an attribute selector.
return aStyleSet.MightHaveAttributeDependency(aElement, aAttribute);
}
void RestyleManager::AttributeWillChange(Element* aElement,
int32_t aNameSpaceID,
nsAtom* aAttribute, int32_t aModType) {
TakeSnapshotForAttributeChange(*aElement, aNameSpaceID, aAttribute);
}
void RestyleManager::ClassAttributeWillBeChangedBySMIL(Element* aElement) {
TakeSnapshotForAttributeChange(*aElement, kNameSpaceID_None,
nsGkAtoms::_class);
}
void RestyleManager::TakeSnapshotForAttributeChange(Element& aElement,
int32_t aNameSpaceID,
nsAtom* aAttribute) {
MOZ_DIAGNOSTIC_ASSERT(!mInStyleRefresh);
bool influencesOtherPseudoClassState;
if (!NeedToRecordAttrChange(*StyleSet(), aElement, aNameSpaceID, aAttribute,
&influencesOtherPseudoClassState)) {
return;
}
// We cannot tell if the attribute change will affect the styles of
// undisplayed elements, because we don't actually restyle those elements
// during the restyle traversal. So just assume that the attribute change can
// cause the style to change.
IncrementUndisplayedRestyleGeneration();
// Relative selector invalidation travels ancestor and earlier sibling
// direction, so it's very possible that it invalidates a styled element.
if (!aElement.HasServoData() &&
!(aElement.GetSelectorFlags() &
NodeSelectorFlags::RelativeSelectorSearchDirectionAncestorSibling)) {
return;
}
// Some other random attribute changes may also affect the transitions,
// so we also set this true here.
mHaveNonAnimationRestyles = true;
ServoElementSnapshot& snapshot = SnapshotFor(aElement);
snapshot.AddAttrs(aElement, aNameSpaceID, aAttribute);
if (influencesOtherPseudoClassState) {
snapshot.AddOtherPseudoClassState(aElement);
}
}
// For some attribute changes we must restyle the whole subtree:
//
// * lang="" and xml:lang="" can affect all descendants due to :lang()
// * exportparts can affect all descendant parts. We could certainly integrate
// it better in the invalidation machinery if it was necessary.
static inline bool AttributeChangeRequiresSubtreeRestyle(
const Element& aElement, nsAtom* aAttr) {
if (aAttr == nsGkAtoms::exportparts) {
// exportparts attribute changes?
return !!aElement.GetShadowRoot();
}
return aAttr == nsGkAtoms::lang;
}
void RestyleManager::AttributeChanged(Element* aElement, int32_t aNameSpaceID,
nsAtom* aAttribute, int32_t aModType,
const nsAttrValue* aOldValue) {
MOZ_ASSERT(!mInStyleRefresh);
auto changeHint = nsChangeHint(0);
auto restyleHint = RestyleHint{0};
changeHint |= aElement->GetAttributeChangeHint(aAttribute, aModType);
MaybeRestyleForNthOfAttribute(aElement, aAttribute, aOldValue);
MaybeRestyleForRelativeSelectorAttribute(aElement, aAttribute, aOldValue);
if (aAttribute == nsGkAtoms::style) {
restyleHint |= RestyleHint::RESTYLE_STYLE_ATTRIBUTE;
} else if (AttributeChangeRequiresSubtreeRestyle(*aElement, aAttribute)) {
restyleHint |= RestyleHint::RestyleSubtree();
} else if (aElement->IsInShadowTree() && aAttribute == nsGkAtoms::part) {
// attribute changes?
restyleHint |= RestyleHint::RESTYLE_SELF | RestyleHint::RESTYLE_PSEUDOS;
}
if (nsIFrame* primaryFrame = aElement->GetPrimaryFrame()) {
// See if we have appearance information for a theme.
StyleAppearance appearance =
primaryFrame->StyleDisplay()->EffectiveAppearance();
if (appearance != StyleAppearance::None) {
nsITheme* theme = PresContext()->Theme();
if (theme->ThemeSupportsWidget(PresContext(), primaryFrame, appearance)) {
bool repaint = false;
theme->WidgetStateChanged(primaryFrame, appearance, aAttribute,
&repaint, aOldValue);
if (repaint) {
changeHint |= nsChangeHint_RepaintFrame;
}
}
}
primaryFrame->AttributeChanged(aNameSpaceID, aAttribute, aModType);
}
if (restyleHint || changeHint) {
Servo_NoteExplicitHints(aElement, restyleHint, changeHint);
}
if (restyleHint) {
// Assuming we need to invalidate cached style in getComputedStyle for
// undisplayed elements, since we don't know if it is needed.
IncrementUndisplayedRestyleGeneration();
// If we change attributes, we have to mark this to be true, so we will
// increase the animation generation for the new created transition if any.
mHaveNonAnimationRestyles = true;
}
}
void RestyleManager::RestyleSiblingsForNthOf(Element* aChild,
NodeSelectorFlags aParentFlags) {
StyleSet()->RestyleSiblingsForNthOf(*aChild,
static_cast<uint32_t>(aParentFlags));
}
void RestyleManager::MaybeRestyleForNthOfAttribute(
Element* aChild, nsAtom* aAttribute, const nsAttrValue* aOldValue) {
const auto* parentNode = aChild->GetParentNode();
MOZ_ASSERT(parentNode);
const auto parentFlags = parentNode->GetSelectorFlags();
if (!(parentFlags & NodeSelectorFlags::HasSlowSelectorNthOf)) {
return;
}
if (!aChild->HasServoData()) {
return;
}
bool mightHaveNthOfDependency;
auto& styleSet = *StyleSet();
if (aAttribute == nsGkAtoms::id) {
auto* const oldAtom = aOldValue->Type() == nsAttrValue::eAtom
? aOldValue->GetAtomValue()
: nullptr;
mightHaveNthOfDependency =
styleSet.MightHaveNthOfIDDependency(*aChild, oldAtom, aChild->GetID());
} else if (aAttribute == nsGkAtoms::_class) {
mightHaveNthOfDependency = styleSet.MightHaveNthOfClassDependency(*aChild);
} else {
mightHaveNthOfDependency =
styleSet.MightHaveNthOfAttributeDependency(*aChild, aAttribute);
}
if (mightHaveNthOfDependency) {
RestyleSiblingsForNthOf(aChild, parentFlags);
}
}
void RestyleManager::MaybeRestyleForRelativeSelectorAttribute(
Element* aElement, nsAtom* aAttribute, const nsAttrValue* aOldValue) {
if (!aElement->HasFlag(ELEMENT_HAS_SNAPSHOT)) {
return;
}
auto& styleSet = *StyleSet();
if (aAttribute == nsGkAtoms::id) {
auto* const oldAtom = aOldValue->Type() == nsAttrValue::eAtom
? aOldValue->GetAtomValue()
: nullptr;
styleSet.MaybeInvalidateRelativeSelectorIDDependency(
*aElement, oldAtom, aElement->GetID(), Snapshots());
} else if (aAttribute == nsGkAtoms::_class) {
styleSet.MaybeInvalidateRelativeSelectorClassDependency(*aElement,
Snapshots());
} else {
styleSet.MaybeInvalidateRelativeSelectorAttributeDependency(
*aElement, aAttribute, Snapshots());
}
}
void RestyleManager::MaybeRestyleForRelativeSelectorState(
ServoStyleSet& aStyleSet, Element* aElement, ElementState aChangedBits) {
if (!aElement->HasFlag(ELEMENT_HAS_SNAPSHOT)) {
return;
}
aStyleSet.MaybeInvalidateRelativeSelectorStateDependency(
*aElement, aChangedBits, Snapshots());
}
void RestyleManager::ReparentComputedStyleForFirstLine(nsIFrame* aFrame) {
// This is only called when moving frames in or out of the first-line
// pseudo-element (or one of its descendants). We can't say much about
// aFrame's ancestors, unfortunately (e.g. during a dynamic insert into
// something inside an inline-block on the first line the ancestors could be
// totally arbitrary), but we will definitely find a line frame on the
// ancestor chain. Note that the lineframe may not actually be the one that
// corresponds to ::first-line; when we're moving _out_ of the ::first-line it
// will be one of the continuations instead.
#ifdef DEBUG
{
nsIFrame* f = aFrame->GetParent();
while (f && !f->IsLineFrame()) {
f = f->GetParent();
}
MOZ_ASSERT(f, "Must have found a first-line frame");
}
#endif
DoReparentComputedStyleForFirstLine(aFrame, *StyleSet());
}
static bool IsFrameAboutToGoAway(nsIFrame* aFrame) {
auto* element = Element::FromNode(aFrame->GetContent());
if (!element) {
return false;
}
return !element->HasServoData();
}
void RestyleManager::DoReparentComputedStyleForFirstLine(
nsIFrame* aFrame, ServoStyleSet& aStyleSet) {
if (aFrame->IsBackdropFrame()) {
// Style context of backdrop frame has no parent style, and thus we do not
// need to reparent it.
return;
}
if (IsFrameAboutToGoAway(aFrame)) {
// We're entering a display: none subtree, which we know it's going to get
// rebuilt. Don't bother reparenting.
return;
}
if (aFrame->IsPlaceholderFrame()) {
// Also reparent the out-of-flow and all its continuations. We're doing
// this to match Gecko for now, but it's not clear that this behavior is
// correct per spec. It's certainly pretty odd for out-of-flows whose
// containing block is not within the first line.
//
// Right now we're somewhat inconsistent in this testcase:
//
// <style>
// div { color: orange; clear: left; }
// div::first-line { color: blue; }
// </style>
// <div>
// <span style="float: left">What color is this text?</span>
// </div>
// <div>
// <span><span style="float: left">What color is this text?</span></span>
// </div>
//
// We make the first float orange and the second float blue. On the other
// hand, if the float were within an inline-block that was on the first
// line, arguably it _should_ inherit from the ::first-line...
nsIFrame* outOfFlow =
nsPlaceholderFrame::GetRealFrameForPlaceholder(aFrame);
MOZ_ASSERT(outOfFlow, "no out-of-flow frame");
for (; outOfFlow; outOfFlow = outOfFlow->GetNextContinuation()) {
DoReparentComputedStyleForFirstLine(outOfFlow, aStyleSet);
}
}
// FIXME(emilio): This is the only caller of GetParentComputedStyle, let's try
// to remove it?
nsIFrame* providerFrame;
ComputedStyle* newParentStyle =
aFrame->GetParentComputedStyle(&providerFrame);
// If our provider is our child, we want to reparent it first, because we
// inherit style from it.
bool isChild = providerFrame && providerFrame->GetParent() == aFrame;
nsIFrame* providerChild = nullptr;
if (isChild) {
DoReparentComputedStyleForFirstLine(providerFrame, aStyleSet);
// Get the style again after ReparentComputedStyle() which might have
// changed it.
newParentStyle = providerFrame->Style();
providerChild = providerFrame;
MOZ_ASSERT(!providerFrame->HasAnyStateBits(NS_FRAME_OUT_OF_FLOW),
"Out of flow provider?");
}
if (!newParentStyle) {
// No need to do anything here for this frame, but we should still reparent
// its descendants, because those may have styles that inherit from the
// parent of this frame (e.g. non-anonymous columns in an anonymous
// colgroup).
MOZ_ASSERT(aFrame->Style()->IsNonInheritingAnonBox(),
"Why did this frame not end up with a parent context?");
ReparentFrameDescendants(aFrame, providerChild, aStyleSet);
return;
}
bool isElement = aFrame->GetContent()->IsElement();
// We probably don't want to initiate transitions from ReparentComputedStyle,
// since we call it during frame construction rather than in response to
// dynamic changes.
// Also see the comment at the start of
// nsTransitionManager::ConsiderInitiatingTransition.
//
// We don't try to do the fancy copying from previous continuations that
// GeckoRestyleManager does here, because that relies on knowing the parents
// of ComputedStyles, and we don't know those.
ComputedStyle* oldStyle = aFrame->Style();
Element* ourElement = isElement ? aFrame->GetContent()->AsElement() : nullptr;
ComputedStyle* newParent = newParentStyle;
if (!providerFrame) {
// No providerFrame means we inherited from a display:contents thing. Our
// layout parent style is the style of our nearest ancestor frame. But we
// have to be careful to do that with our placeholder, not with us, if we're
// out of flow.
if (aFrame->HasAnyStateBits(NS_FRAME_OUT_OF_FLOW)) {
aFrame->FirstContinuation()
->GetPlaceholderFrame()
->GetLayoutParentStyleForOutOfFlow(&providerFrame);
} else {
providerFrame = nsIFrame::CorrectStyleParentFrame(
aFrame->GetParent(), oldStyle->GetPseudoType());
}
}
ComputedStyle* layoutParent = providerFrame->Style();
RefPtr<ComputedStyle> newStyle = aStyleSet.ReparentComputedStyle(
oldStyle, newParent, layoutParent, ourElement);
aFrame->SetComputedStyle(newStyle);
// This logic somewhat mirrors the logic in
// RestyleManager::ProcessPostTraversal.
if (isElement) {
// We can't use UpdateAdditionalComputedStyles as-is because it needs a
// ServoRestyleState and maintaining one of those during a _frametree_
// traversal is basically impossible.
int32_t index = 0;
while (auto* oldAdditionalStyle =
aFrame->GetAdditionalComputedStyle(index)) {
RefPtr<ComputedStyle> newAdditionalContext =
aStyleSet.ReparentComputedStyle(oldAdditionalStyle, newStyle,
newStyle, nullptr);
aFrame->SetAdditionalComputedStyle(index, newAdditionalContext);
++index;
}
}
// Generally, owned anon boxes are our descendants. The only exceptions are
// tables (for the table wrapper) and inline frames (for the block part of the
// block-in-inline split). We're going to update our descendants when looping
// over kids, and we don't want to update the block part of a block-in-inline
// split if the inline is on the first line but the block is not (and if the
// block is, it's the child of something else on the first line and will get
// updated as a child). And given how this method ends up getting called, if
// we reach here for a table frame, we are already in the middle of
// reparenting the table wrapper frame. So no need to
// UpdateStyleOfOwnedAnonBoxes() here.
ReparentFrameDescendants(aFrame, providerChild, aStyleSet);
// We do not need to do the equivalent of UpdateFramePseudoElementStyles,
// because those are handled by our descendant walk.
}
void RestyleManager::ReparentFrameDescendants(nsIFrame* aFrame,
nsIFrame* aProviderChild,
ServoStyleSet& aStyleSet) {
for (const auto& childList : aFrame->ChildLists()) {
for (nsIFrame* child : childList.mList) {
// only do frames that are in flow
if (!child->HasAnyStateBits(NS_FRAME_OUT_OF_FLOW) &&
child != aProviderChild) {
DoReparentComputedStyleForFirstLine(child, aStyleSet);
}
}
}
}
} // namespace mozilla