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gecko-dev/layout/base/GeckoRestyleManager.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/**
* Code responsible for managing style changes: tracking what style
* changes need to happen, scheduling them, and doing them.
*/
#include "mozilla/GeckoRestyleManager.h"
#include <algorithm> // For std::max
#include "mozilla/EffectSet.h"
#include "mozilla/EventStates.h"
#include "mozilla/ViewportFrame.h"
#include "mozilla/css/StyleRule.h" // For nsCSSSelector
#include "nsLayoutUtils.h"
#include "AnimationCommon.h" // For GetLayerAnimationInfo
#include "FrameLayerBuilder.h"
#include "GeckoProfiler.h"
#include "nsAutoPtr.h"
#include "nsStyleChangeList.h"
#include "nsRuleProcessorData.h"
#include "nsStyleSet.h"
#include "nsStyleUtil.h"
#include "nsCSSFrameConstructor.h"
#include "nsSVGEffects.h"
#include "nsCSSPseudoElements.h"
#include "nsCSSRendering.h"
#include "nsAnimationManager.h"
#include "nsTransitionManager.h"
#include "nsViewManager.h"
#include "nsRenderingContext.h"
#include "nsSVGIntegrationUtils.h"
#include "nsCSSAnonBoxes.h"
#include "nsContainerFrame.h"
#include "nsPlaceholderFrame.h"
#include "nsBlockFrame.h"
#include "SVGTextFrame.h"
#include "StickyScrollContainer.h"
#include "nsIRootBox.h"
#include "nsIDOMMutationEvent.h"
#include "nsContentUtils.h"
#include "nsIFrameInlines.h"
#include "ActiveLayerTracker.h"
#include "nsDisplayList.h"
#include "RestyleTrackerInlines.h"
#include "nsSMILAnimationController.h"
#include "nsCSSRuleProcessor.h"
#include "ChildIterator.h"
#ifdef ACCESSIBILITY
#include "nsAccessibilityService.h"
#endif
namespace mozilla {
using namespace layers;
using namespace dom;
#define LOG_RESTYLE_CONTINUE(reason_, ...) \
LOG_RESTYLE("continuing restyle since " reason_, ##__VA_ARGS__)
#ifdef RESTYLE_LOGGING
static nsCString
FrameTagToString(const nsIFrame* aFrame)
{
nsCString result;
aFrame->ListTag(result);
return result;
}
static nsCString
ElementTagToString(dom::Element* aElement)
{
nsCString result;
nsDependentAtomString buf(aElement->NodeInfo()->NameAtom());
result.AppendPrintf("(%s@%p)", NS_ConvertUTF16toUTF8(buf).get(), aElement);
return result;
}
#endif
GeckoRestyleManager::GeckoRestyleManager(nsPresContext* aPresContext)
: RestyleManager(StyleBackendType::Gecko, aPresContext)
, mDoRebuildAllStyleData(false)
, mInRebuildAllStyleData(false)
, mSkipAnimationRules(false)
, mHavePendingNonAnimationRestyles(false)
, mRebuildAllExtraHint(nsChangeHint(0))
, mRebuildAllRestyleHint(nsRestyleHint(0))
, mReframingStyleContexts(nullptr)
, mPendingRestyles(ELEMENT_HAS_PENDING_RESTYLE |
ELEMENT_IS_POTENTIAL_RESTYLE_ROOT |
ELEMENT_IS_CONDITIONAL_RESTYLE_ANCESTOR)
, mIsProcessingRestyles(false)
#ifdef RESTYLE_LOGGING
, mLoggingDepth(0)
#endif
{
mPendingRestyles.Init(this);
}
void
GeckoRestyleManager::RestyleElement(Element* aElement,
nsIFrame* aPrimaryFrame,
nsChangeHint aMinHint,
RestyleTracker& aRestyleTracker,
nsRestyleHint aRestyleHint,
const RestyleHintData& aRestyleHintData)
{
MOZ_ASSERT(mReframingStyleContexts, "should have rsc");
NS_ASSERTION(aPrimaryFrame == aElement->GetPrimaryFrame(),
"frame/content mismatch");
if (aPrimaryFrame && aPrimaryFrame->GetContent() != aElement) {
// XXXbz this is due to image maps messing with the primary frame pointer
// of <area>s. See bug 135040. We can remove this block once that's fixed.
aPrimaryFrame = nullptr;
}
NS_ASSERTION(!aPrimaryFrame || aPrimaryFrame->GetContent() == aElement,
"frame/content mismatch");
// If we're restyling the root element and there are 'rem' units in
// use, handle dynamic changes to the definition of a 'rem' here.
if (PresContext()->UsesRootEMUnits() && aPrimaryFrame &&
!mInRebuildAllStyleData) {
nsStyleContext* oldContext = aPrimaryFrame->StyleContext();
if (!oldContext->GetParent()) { // check that we're the root element
RefPtr<nsStyleContext> newContext = StyleSet()->
ResolveStyleFor(aElement, nullptr /* == oldContext->GetParent() */);
if (oldContext->StyleFont()->mFont.size !=
newContext->StyleFont()->mFont.size) {
// The basis for 'rem' units has changed.
mRebuildAllRestyleHint |= aRestyleHint;
if (aRestyleHint & eRestyle_SomeDescendants) {
mRebuildAllRestyleHint |= eRestyle_Subtree;
}
mRebuildAllExtraHint |= aMinHint;
StartRebuildAllStyleData(aRestyleTracker);
return;
}
}
}
if (aMinHint & nsChangeHint_ReconstructFrame) {
FrameConstructor()->RecreateFramesForContent(aElement, false,
nsCSSFrameConstructor::REMOVE_FOR_RECONSTRUCTION, nullptr);
} else if (aPrimaryFrame) {
ComputeAndProcessStyleChange(aPrimaryFrame, aMinHint, aRestyleTracker,
aRestyleHint, aRestyleHintData);
} else if (aRestyleHint & ~eRestyle_LaterSiblings) {
// We're restyling an element with no frame, so we should try to
// make one if its new style says it should have one. But in order
// to try to honor the restyle hint (which we'd like to do so that,
// for example, an animation-only style flush doesn't flush other
// buffered style changes), we only do this if the restyle hint says
// we have *some* restyling for this frame. This means we'll
// potentially get ahead of ourselves in that case, but not as much
// as we would if we didn't check the restyle hint.
nsStyleContext* newContext =
FrameConstructor()->MaybeRecreateFramesForElement(aElement);
if (newContext &&
newContext->StyleDisplay()->mDisplay == StyleDisplay::Contents) {
// Style change for a display:contents node that did not recreate frames.
ComputeAndProcessStyleChange(newContext, aElement, aMinHint,
aRestyleTracker, aRestyleHint,
aRestyleHintData);
}
}
}
GeckoRestyleManager::ReframingStyleContexts
::ReframingStyleContexts(
GeckoRestyleManager* aRestyleManager)
: mRestyleManager(aRestyleManager)
, mRestorePointer(mRestyleManager->mReframingStyleContexts)
{
MOZ_ASSERT(!mRestyleManager->mReframingStyleContexts,
"shouldn't construct recursively");
mRestyleManager->mReframingStyleContexts = this;
}
GeckoRestyleManager::ReframingStyleContexts::~ReframingStyleContexts()
{
// Before we go away, we need to flush out any frame construction that
// was enqueued, so that we initiate transitions.
// Note that this is a little bit evil in that we're calling into code
// that calls our member functions from our destructor, but it's at
// the beginning of our destructor, so it shouldn't be too bad.
mRestyleManager->PresContext()->FrameConstructor()->CreateNeededFrames();
}
static inline dom::Element*
ElementForStyleContext(nsIContent* aParentContent,
nsIFrame* aFrame,
CSSPseudoElementType aPseudoType);
// Forwarded nsIDocumentObserver method, to handle restyling (and
// passing the notification to the frame).
void
GeckoRestyleManager::ContentStateChanged(nsIContent* aContent,
EventStates aStateMask)
{
// XXXbz it would be good if this function only took Elements, but
// we'd have to make ESM guarantee that usefully.
if (!aContent->IsElement()) {
return;
}
Element* aElement = aContent->AsElement();
nsChangeHint changeHint;
nsRestyleHint restyleHint;
ContentStateChangedInternal(aElement, aStateMask, &changeHint, &restyleHint);
PostRestyleEvent(aElement, restyleHint, changeHint);
}
// Forwarded nsIMutationObserver method, to handle restyling.
void
GeckoRestyleManager::AttributeWillChange(Element* aElement,
int32_t aNameSpaceID,
nsIAtom* aAttribute,
int32_t aModType,
const nsAttrValue* aNewValue)
{
RestyleHintData rsdata;
nsRestyleHint rshint =
StyleSet()->HasAttributeDependentStyle(aElement,
aNameSpaceID,
aAttribute,
aModType,
false,
aNewValue,
rsdata);
PostRestyleEvent(aElement, rshint, nsChangeHint(0), &rsdata);
}
// Forwarded nsIMutationObserver method, to handle restyling (and
// passing the notification to the frame).
void
GeckoRestyleManager::AttributeChanged(Element* aElement,
int32_t aNameSpaceID,
nsIAtom* aAttribute,
int32_t aModType,
const nsAttrValue* aOldValue)
{
MOZ_ASSERT(!mInStyleRefresh);
// Hold onto the PresShell to prevent ourselves from being destroyed.
// XXXbz how, exactly, would this attribute change cause us to be
// destroyed from inside this function?
nsCOMPtr<nsIPresShell> shell = PresContext()->GetPresShell();
mozilla::Unused << shell; // Unused within this function
// Get the frame associated with the content which is the highest in the frame tree
nsIFrame* primaryFrame = aElement->GetPrimaryFrame();
#if 0
NS_FRAME_LOG(NS_FRAME_TRACE_CALLS,
("RestyleManager::AttributeChanged: content=%p[%s] frame=%p",
aContent, ContentTag(aElement, 0), frame));
#endif
// the style tag has its own interpretation based on aHint
nsChangeHint hint = aElement->GetAttributeChangeHint(aAttribute, aModType);
bool reframe = (hint & nsChangeHint_ReconstructFrame) != 0;
#ifdef MOZ_XUL
// The following listbox widget trap prevents offscreen listbox widget
// content from being removed and re-inserted (which is what would
// happen otherwise).
if (!primaryFrame && !reframe) {
int32_t namespaceID;
nsIAtom* tag = PresContext()->Document()->BindingManager()->
ResolveTag(aElement, &namespaceID);
if (namespaceID == kNameSpaceID_XUL &&
(tag == nsGkAtoms::listitem ||
tag == nsGkAtoms::listcell))
return;
}
if (aAttribute == nsGkAtoms::tooltiptext ||
aAttribute == nsGkAtoms::tooltip)
{
nsIRootBox* rootBox = nsIRootBox::GetRootBox(PresContext()->GetPresShell());
if (rootBox) {
if (aModType == nsIDOMMutationEvent::REMOVAL)
rootBox->RemoveTooltipSupport(aElement);
if (aModType == nsIDOMMutationEvent::ADDITION)
rootBox->AddTooltipSupport(aElement);
}
}
#endif // MOZ_XUL
if (primaryFrame) {
// See if we have appearance information for a theme.
const nsStyleDisplay* disp = primaryFrame->StyleDisplay();
if (disp->mAppearance) {
nsITheme* theme = PresContext()->GetTheme();
if (theme && theme->ThemeSupportsWidget(PresContext(), primaryFrame, disp->mAppearance)) {
bool repaint = false;
theme->WidgetStateChanged(primaryFrame, disp->mAppearance, aAttribute,
&repaint, aOldValue);
if (repaint)
hint |= nsChangeHint_RepaintFrame;
}
}
// let the frame deal with it now, so we don't have to deal later
primaryFrame->AttributeChanged(aNameSpaceID, aAttribute, aModType);
// XXXwaterson should probably check for IB split siblings
// here, and propagate the AttributeChanged notification to
// them, as well. Currently, inline frames don't do anything on
// this notification, so it's not that big a deal.
}
// See if we can optimize away the style re-resolution -- must be called after
// the frame's AttributeChanged() in case it does something that affects the style
RestyleHintData rsdata;
nsRestyleHint rshint =
StyleSet()->HasAttributeDependentStyle(aElement,
aNameSpaceID,
aAttribute,
aModType,
true,
aOldValue,
rsdata);
PostRestyleEvent(aElement, rshint, hint, &rsdata);
}
void
GeckoRestyleManager::RebuildAllStyleData(nsChangeHint aExtraHint,
nsRestyleHint aRestyleHint)
{
NS_ASSERTION(!(aExtraHint & nsChangeHint_ReconstructFrame),
"Should not reconstruct the root of the frame tree. "
"Use ReconstructDocElementHierarchy instead.");
MOZ_ASSERT(!(aRestyleHint & ~(eRestyle_Subtree | eRestyle_ForceDescendants)),
"the only bits allowed in aRestyleHint are eRestyle_Subtree and "
"eRestyle_ForceDescendants");
mRebuildAllExtraHint |= aExtraHint;
mRebuildAllRestyleHint |= aRestyleHint;
// Processing the style changes could cause a flush that propagates to
// the parent frame and thus destroys the pres shell, so we must hold
// a reference.
nsCOMPtr<nsIPresShell> presShell = PresContext()->GetPresShell();
if (!presShell || !presShell->GetRootFrame()) {
mDoRebuildAllStyleData = false;
return;
}
// Make sure that the viewmanager will outlive the presshell
RefPtr<nsViewManager> vm = presShell->GetViewManager();
mozilla::Unused << vm; // Not used within this function
// We may reconstruct frames below and hence process anything that is in the
// tree. We don't want to get notified to process those items again after.
presShell->GetDocument()->FlushPendingNotifications(FlushType::ContentAndNotify);
nsAutoScriptBlocker scriptBlocker;
mDoRebuildAllStyleData = true;
ProcessPendingRestyles();
}
void
GeckoRestyleManager::StartRebuildAllStyleData(RestyleTracker& aRestyleTracker)
{
MOZ_ASSERT(mIsProcessingRestyles);
nsIFrame* rootFrame = PresContext()->PresShell()->GetRootFrame();
if (!rootFrame) {
// No need to do anything.
return;
}
mInRebuildAllStyleData = true;
// Tell the style set to get the old rule tree out of the way
// so we can recalculate while maintaining rule tree immutability
nsresult rv = StyleSet()->BeginReconstruct();
if (NS_FAILED(rv)) {
MOZ_CRASH("unable to rebuild style data");
}
nsRestyleHint restyleHint = mRebuildAllRestyleHint;
nsChangeHint changeHint = mRebuildAllExtraHint;
mRebuildAllExtraHint = nsChangeHint(0);
mRebuildAllRestyleHint = nsRestyleHint(0);
restyleHint |= eRestyle_ForceDescendants;
if (!(restyleHint & eRestyle_Subtree) &&
(restyleHint & ~(eRestyle_Force | eRestyle_ForceDescendants))) {
// We want this hint to apply to the root node's primary frame
// rather than the root frame, since it's the primary frame that has
// the styles for the root element (rather than the ancestors of the
// primary frame whose mContent is the root node but which have
// different styles). If we use up the hint for one of the
// ancestors that we hit first, then we'll fail to do the restyling
// we need to do.
Element* root = PresContext()->Document()->GetRootElement();
if (root) {
// If the root element is gone, dropping the hint on the floor
// should be fine.
aRestyleTracker.AddPendingRestyle(root, restyleHint, nsChangeHint(0));
}
restyleHint = nsRestyleHint(0);
}
// Recalculate all of the style contexts for the document, from the
// root frame. We can't do this with a change hint, since we can't
// post a change hint for the root frame.
// Note that we can ignore the return value of ComputeStyleChangeFor
// because we never need to reframe the root frame.
// XXX Does it matter that we're passing aExtraHint to the real root
// frame and not the root node's primary frame? (We could do
// roughly what we do for aRestyleHint above.)
ComputeAndProcessStyleChange(rootFrame,
changeHint, aRestyleTracker, restyleHint,
RestyleHintData());
}
void
GeckoRestyleManager::FinishRebuildAllStyleData()
{
MOZ_ASSERT(mInRebuildAllStyleData, "bad caller");
// Tell the style set it's safe to destroy the old rule tree. We
// must do this after the ProcessRestyledFrames call in case the
// change list has frame reconstructs in it (since frames to be
// reconstructed will still have their old style context pointers
// until they are destroyed).
StyleSet()->EndReconstruct();
mInRebuildAllStyleData = false;
}
void
GeckoRestyleManager::ProcessPendingRestyles()
{
NS_PRECONDITION(PresContext()->Document(), "No document? Pshaw!");
NS_PRECONDITION(!nsContentUtils::IsSafeToRunScript(),
"Missing a script blocker!");
// First do any queued-up frame creation. (We should really
// merge this into the rest of the process, though; see bug 827239.)
PresContext()->FrameConstructor()->CreateNeededFrames();
// Process non-animation restyles...
MOZ_ASSERT(!mIsProcessingRestyles,
"Nesting calls to ProcessPendingRestyles?");
mIsProcessingRestyles = true;
// Before we process any restyles, we need to ensure that style
// resulting from any animations is up-to-date, so that if any style
// changes we cause trigger transitions, we have the correct old style
// for starting the transition.
bool haveNonAnimation =
mHavePendingNonAnimationRestyles || mDoRebuildAllStyleData;
if (haveNonAnimation) {
++mAnimationGeneration;
UpdateOnlyAnimationStyles();
} else {
// If we don't have non-animation style updates, then we have queued
// up animation style updates from the refresh driver tick. This
// doesn't necessarily include *all* animation style updates, since
// we might be suppressing main-thread updates for some animations,
// so we don't want to call UpdateOnlyAnimationStyles, which updates
// all animations. In other words, the work that we're about to do
// to process the pending restyles queue is a *subset* of the work
// that UpdateOnlyAnimationStyles would do, since we're *not*
// updating transitions that are running on the compositor thread
// and suppressed on the main thread.
//
// But when we update those styles, we want to suppress updates to
// transitions just like we do in UpdateOnlyAnimationStyles. So we
// want to tell the transition manager to act as though we're in
// UpdateOnlyAnimationStyles.
//
// FIXME: In the future, we might want to refactor the way the
// animation and transition manager do their refresh driver ticks so
// that we can use UpdateOnlyAnimationStyles, with a different
// boolean argument, for this update as well, instead of having them
// post style updates in their WillRefresh methods.
PresContext()->TransitionManager()->SetInAnimationOnlyStyleUpdate(true);
}
ProcessRestyles(mPendingRestyles);
if (!haveNonAnimation) {
PresContext()->TransitionManager()->SetInAnimationOnlyStyleUpdate(false);
}
mIsProcessingRestyles = false;
NS_ASSERTION(haveNonAnimation || !mHavePendingNonAnimationRestyles,
"should not have added restyles");
mHavePendingNonAnimationRestyles = false;
if (mDoRebuildAllStyleData) {
// We probably wasted a lot of work up above, but this seems safest
// and it should be rarely used.
// This might add us as a refresh observer again; that's ok.
ProcessPendingRestyles();
NS_ASSERTION(!mDoRebuildAllStyleData,
"repeatedly setting mDoRebuildAllStyleData?");
}
MOZ_ASSERT(!mInRebuildAllStyleData,
"should have called FinishRebuildAllStyleData");
}
void
GeckoRestyleManager::BeginProcessingRestyles(RestyleTracker& aRestyleTracker)
{
// Make sure to not rebuild quote or counter lists while we're
// processing restyles
PresContext()->FrameConstructor()->BeginUpdate();
mInStyleRefresh = true;
if (ShouldStartRebuildAllFor(aRestyleTracker)) {
mDoRebuildAllStyleData = false;
StartRebuildAllStyleData(aRestyleTracker);
}
}
void
GeckoRestyleManager::EndProcessingRestyles()
{
FlushOverflowChangedTracker();
MOZ_ASSERT(mAnimationsWithDestroyedFrame);
mAnimationsWithDestroyedFrame->
StopAnimationsForElementsWithoutFrames();
// Set mInStyleRefresh to false now, since the EndUpdate call might
// add more restyles.
mInStyleRefresh = false;
if (mInRebuildAllStyleData) {
FinishRebuildAllStyleData();
}
PresContext()->FrameConstructor()->EndUpdate();
#ifdef DEBUG
PresContext()->PresShell()->VerifyStyleTree();
#endif
}
void
GeckoRestyleManager::UpdateOnlyAnimationStyles()
{
bool doCSS = PresContext()->EffectCompositor()->HasPendingStyleUpdates();
nsIDocument* document = PresContext()->Document();
nsSMILAnimationController* animationController =
document->HasAnimationController() ?
document->GetAnimationController() :
nullptr;
bool doSMIL = animationController &&
animationController->MightHavePendingStyleUpdates();
if (!doCSS && !doSMIL) {
return;
}
nsTransitionManager* transitionManager = PresContext()->TransitionManager();
transitionManager->SetInAnimationOnlyStyleUpdate(true);
RestyleTracker tracker(ELEMENT_HAS_PENDING_ANIMATION_ONLY_RESTYLE |
ELEMENT_IS_POTENTIAL_ANIMATION_ONLY_RESTYLE_ROOT);
tracker.Init(this);
if (doCSS) {
PresContext()->EffectCompositor()->AddStyleUpdatesTo(tracker);
}
if (doSMIL) {
animationController->AddStyleUpdatesTo(tracker);
}
ProcessRestyles(tracker);
transitionManager->SetInAnimationOnlyStyleUpdate(false);
}
void
GeckoRestyleManager::PostRestyleEventInternal()
{
// Make sure we're not in a style refresh; if we are, we still have
// a call to ProcessPendingRestyles coming and there's no need to
// add ourselves as a refresh observer until then.
nsIPresShell* presShell = PresContext()->PresShell();
if (!mInStyleRefresh) {
presShell->ObserveStyleFlushes();
}
// Unconditionally flag our document as needing a flush. The other
// option here would be a dedicated boolean to track whether we need
// to do so (set here and unset in ProcessPendingRestyles).
presShell->SetNeedStyleFlush();
}
void
GeckoRestyleManager::PostRestyleEvent(Element* aElement,
nsRestyleHint aRestyleHint,
nsChangeHint aMinChangeHint,
const RestyleHintData* aRestyleHintData)
{
if (MOZ_UNLIKELY(IsDisconnected()) ||
MOZ_UNLIKELY(PresContext()->PresShell()->IsDestroying())) {
return;
}
if (aRestyleHint == 0 && !aMinChangeHint) {
// Nothing to do here
return;
}
mPendingRestyles.AddPendingRestyle(aElement, aRestyleHint, aMinChangeHint,
aRestyleHintData);
// Set mHavePendingNonAnimationRestyles for any restyle that could
// possibly contain non-animation styles (i.e., those that require us
// to do an animation-only style flush before processing style changes
// to ensure correct initialization of CSS transitions).
if (aRestyleHint & ~eRestyle_AllHintsWithAnimations) {
mHavePendingNonAnimationRestyles = true;
}
PostRestyleEventInternal();
}
void
GeckoRestyleManager::PostRebuildAllStyleDataEvent(nsChangeHint aExtraHint,
nsRestyleHint aRestyleHint)
{
NS_ASSERTION(!(aExtraHint & nsChangeHint_ReconstructFrame),
"Should not reconstruct the root of the frame tree. "
"Use ReconstructDocElementHierarchy instead.");
MOZ_ASSERT(!(aRestyleHint & eRestyle_SomeDescendants),
"PostRebuildAllStyleDataEvent does not handle "
"eRestyle_SomeDescendants");
mDoRebuildAllStyleData = true;
mRebuildAllExtraHint |= aExtraHint;
mRebuildAllRestyleHint |= aRestyleHint;
// Get a restyle event posted if necessary
PostRestyleEventInternal();
}
// aContent must be the content for the frame in question, which may be
// :before/:after content
/* static */ bool
GeckoRestyleManager::TryInitiatingTransition(nsPresContext* aPresContext,
nsIContent* aContent,
nsStyleContext* aOldStyleContext,
RefPtr<nsStyleContext>*
aNewStyleContext /* inout */)
{
if (!aContent || !aContent->IsElement()) {
return false;
}
// Notify the transition manager. If it starts a transition,
// it might modify the new style context.
RefPtr<nsStyleContext> sc = *aNewStyleContext;
aPresContext->TransitionManager()->StyleContextChanged(
aContent->AsElement(), aOldStyleContext, aNewStyleContext);
return *aNewStyleContext != sc;
}
static dom::Element*
ElementForStyleContext(nsIContent* aParentContent,
nsIFrame* aFrame,
CSSPseudoElementType aPseudoType)
{
// We don't expect XUL tree stuff here.
NS_PRECONDITION(aPseudoType == CSSPseudoElementType::NotPseudo ||
aPseudoType == CSSPseudoElementType::InheritingAnonBox ||
aPseudoType == CSSPseudoElementType::NonInheritingAnonBox ||
aPseudoType < CSSPseudoElementType::Count,
"Unexpected pseudo");
// XXX see the comments about the various element confusion in
// ElementRestyler::Restyle.
if (aPseudoType == CSSPseudoElementType::NotPseudo) {
return aFrame->GetContent()->AsElement();
}
if (aPseudoType == CSSPseudoElementType::InheritingAnonBox ||
aPseudoType == CSSPseudoElementType::NonInheritingAnonBox) {
return nullptr;
}
if (aPseudoType == CSSPseudoElementType::firstLetter) {
NS_ASSERTION(aFrame->IsLetterFrame(),
"firstLetter pseudoTag without a nsFirstLetterFrame");
nsBlockFrame* block = nsBlockFrame::GetNearestAncestorBlock(aFrame);
return block->GetContent()->AsElement();
}
if (aPseudoType == CSSPseudoElementType::mozColorSwatch) {
MOZ_ASSERT(aFrame->GetParent() &&
aFrame->GetParent()->GetParent(),
"Color swatch frame should have a parent & grandparent");
nsIFrame* grandparentFrame = aFrame->GetParent()->GetParent();
MOZ_ASSERT(grandparentFrame->IsColorControlFrame(),
"Color swatch's grandparent should be nsColorControlFrame");
return grandparentFrame->GetContent()->AsElement();
}
if (aPseudoType == CSSPseudoElementType::mozNumberText ||
aPseudoType == CSSPseudoElementType::mozNumberWrapper ||
aPseudoType == CSSPseudoElementType::mozNumberSpinBox ||
aPseudoType == CSSPseudoElementType::mozNumberSpinUp ||
aPseudoType == CSSPseudoElementType::mozNumberSpinDown) {
// Get content for nearest nsNumberControlFrame:
nsIFrame* f = aFrame->GetParent();
MOZ_ASSERT(f);
while (!f->IsNumberControlFrame()) {
f = f->GetParent();
MOZ_ASSERT(f);
}
return f->GetContent()->AsElement();
}
Element* frameElement = aFrame->GetContent()->AsElement();
if (frameElement->IsNativeAnonymous() &&
nsCSSPseudoElements::PseudoElementIsJSCreatedNAC(aPseudoType)) {
// NAC-implemented pseudos use the closest non-NAC element as their
// element to inherit from.
//
// FIXME(heycam): In theory we shouldn't need to limit this only to
// JS-created pseudo-implementing NAC, as all pseudo-implementing
// should use the closest non-native anonymous ancestor element as
// its originating element. But removing that part of the condition
// reveals some bugs in style resultion with display:contents and
// XBL. See bug 1345809.
Element* originatingElement =
nsContentUtils::GetClosestNonNativeAnonymousAncestor(frameElement);
if (originatingElement) {
return originatingElement;
}
}
if (aParentContent) {
return aParentContent->AsElement();
}
MOZ_ASSERT(aFrame->GetContent()->GetParent(),
"should not have got here for the root element");
return aFrame->GetContent()->GetParent()->AsElement();
}
/**
* Some pseudo-elements actually have a content node created for them,
* whereas others have only a frame but not a content node. In some
* cases, we want to support style attributes or states on those
* elements. For those pseudo-elements, we need to pass the
* anonymous pseudo-element content to selector matching processes in
* addition to the element that the pseudo-element is for; in other
* cases we should pass null instead. This function returns the
* pseudo-element content that we should pass.
*/
static dom::Element*
PseudoElementForStyleContext(nsIFrame* aFrame,
CSSPseudoElementType aPseudoType)
{
if (aPseudoType >= CSSPseudoElementType::Count) {
return nullptr;
}
if (nsCSSPseudoElements::PseudoElementSupportsStyleAttribute(aPseudoType) ||
nsCSSPseudoElements::PseudoElementSupportsUserActionState(aPseudoType)) {
return aFrame->GetContent()->AsElement();
}
return nullptr;
}
/**
* FIXME: Temporary. Should merge with following function.
*/
static nsIFrame*
GetPrevContinuationWithPossiblySameStyle(nsIFrame* aFrame)
{
// Account for {ib} splits when looking for "prevContinuation". In
// particular, for the first-continuation of a part of an {ib} split
// we want to use the previous ib-split sibling of the previous
// ib-split sibling of aFrame, which should have the same style
// context as aFrame itself. In particular, if aFrame is the first
// continuation of an inline part of a block-in-inline split then its
// previous ib-split sibling is a block, and the previous ib-split
// sibling of _that_ is an inline, just like aFrame. Similarly, if
// aFrame is the first continuation of a block part of an
// block-in-inline split (a block-in-inline wrapper block), then its
// previous ib-split sibling is an inline and the previous ib-split
// sibling of that is either another block-in-inline wrapper block box
// or null.
nsIFrame* prevContinuation = aFrame->GetPrevContinuation();
if (!prevContinuation &&
(aFrame->GetStateBits() & NS_FRAME_PART_OF_IBSPLIT)) {
// We're the first continuation, so we can just get the frame
// property directly
prevContinuation =
aFrame->GetProperty(nsIFrame::IBSplitPrevSibling());
if (prevContinuation) {
prevContinuation =
prevContinuation->GetProperty(nsIFrame::IBSplitPrevSibling());
}
}
NS_ASSERTION(!prevContinuation ||
prevContinuation->GetContent() == aFrame->GetContent(),
"unexpected content mismatch");
return prevContinuation;
}
/**
* Get the previous continuation or similar ib-split sibling (assuming
* block/inline alternation), conditionally on it having the same style.
* This assumes that we're not between resolving the two (i.e., that
* they're both already resolved.
*/
static nsIFrame*
GetPrevContinuationWithSameStyle(nsIFrame* aFrame)
{
nsIFrame* prevContinuation = GetPrevContinuationWithPossiblySameStyle(aFrame);
if (!prevContinuation) {
return nullptr;
}
nsStyleContext* prevStyle = prevContinuation->StyleContext();
nsStyleContext* selfStyle = aFrame->StyleContext();
if (prevStyle != selfStyle) {
NS_ASSERTION(prevStyle->GetPseudo() != selfStyle->GetPseudo() ||
prevStyle->GetParent() != selfStyle->GetParent(),
"continuations should have the same style context");
prevContinuation = nullptr;
}
return prevContinuation;
}
nsresult
GeckoRestyleManager::ReparentStyleContext(nsIFrame* aFrame)
{
LayoutFrameType frameType = aFrame->Type();
if (frameType == LayoutFrameType::Placeholder) {
// Also reparent the out-of-flow and all its continuations.
nsIFrame* outOfFlow =
nsPlaceholderFrame::GetRealFrameForPlaceholder(aFrame);
NS_ASSERTION(outOfFlow, "no out-of-flow frame");
do {
ReparentStyleContext(outOfFlow);
} while ((outOfFlow = outOfFlow->GetNextContinuation()));
} else if (frameType == LayoutFrameType::Backdrop) {
// Style context of backdrop frame has no parent style context, and
// thus we do not need to reparent it.
return NS_OK;
}
// DO NOT verify the style tree before reparenting. The frame
// tree has already been changed, so this check would just fail.
nsStyleContext* oldContext = aFrame->StyleContext();
RefPtr<nsStyleContext> newContext;
nsIFrame* providerFrame;
nsStyleContext* newParentContext = aFrame->GetParentStyleContext(&providerFrame);
bool isChild = providerFrame && providerFrame->GetParent() == aFrame;
nsIFrame* providerChild = nullptr;
if (isChild) {
ReparentStyleContext(providerFrame);
// Get the style context again after ReparentStyleContext() which might have
// changed it.
newParentContext = providerFrame->StyleContext();
providerChild = providerFrame;
}
#ifdef DEBUG
{
// Check that our assumption that continuations of the same
// pseudo-type and with the same style context parent have the
// same style context is valid before the reresolution. (We need
// to check the pseudo-type and style context parent because of
// :first-letter and :first-line, where we create styled and
// unstyled letter/line frames distinguished by pseudo-type, and
// then need to distinguish their descendants based on having
// different parents.)
nsIFrame* nextContinuation = aFrame->GetNextContinuation();
if (nextContinuation) {
nsStyleContext* nextContinuationContext =
nextContinuation->StyleContext();
NS_ASSERTION(oldContext == nextContinuationContext ||
oldContext->GetPseudo() !=
nextContinuationContext->GetPseudo() ||
oldContext->GetParent() !=
nextContinuationContext->GetParent(),
"continuations should have the same style context");
}
}
#endif
if (!newParentContext && !oldContext->GetParent()) {
// No need to do anything here.
#ifdef DEBUG
// Make sure we have no children, so we really know there is nothing to do.
nsIFrame::ChildListIterator lists(aFrame);
for (; !lists.IsDone(); lists.Next()) {
MOZ_ASSERT(lists.CurrentList().IsEmpty(),
"Failing to reparent style context for child of "
"non-inheriting anon box");
}
#endif // DEBUG
return NS_OK;
}
NS_ASSERTION(newParentContext, "Reparenting something that has no usable"
" parent? Shouldn't happen!");
// XXX need to do something here to produce the correct style context for
// an IB split whose first inline part is inside a first-line frame.
// Currently the first IB anonymous block's style context takes the first
// part's style context as parent, which is wrong since first-line style
// should not apply to the anonymous block.
nsIFrame* prevContinuation =
GetPrevContinuationWithPossiblySameStyle(aFrame);
nsStyleContext* prevContinuationContext;
bool copyFromContinuation =
prevContinuation &&
(prevContinuationContext = prevContinuation->StyleContext())
->GetPseudo() == oldContext->GetPseudo() &&
prevContinuationContext->GetParent() == newParentContext;
if (copyFromContinuation) {
// Just use the style context from the frame's previous
// continuation (see assertion about aFrame->GetNextContinuation()
// above, which we would have previously hit for aFrame's previous
// continuation).
newContext = prevContinuationContext;
} else {
nsIFrame* parentFrame = aFrame->GetParent();
Element* element =
ElementForStyleContext(parentFrame ? parentFrame->GetContent() : nullptr,
aFrame,
oldContext->GetPseudoType());
newContext = StyleSet()->
ReparentStyleContext(oldContext, newParentContext, element);
}
if (newContext) {
if (newContext != oldContext) {
// We probably don't want to initiate transitions from
// ReparentStyleContext, since we call it during frame
// construction rather than in response to dynamic changes.
// Also see the comment at the start of
// nsTransitionManager::ConsiderInitiatingTransition.
#if 0
if (!copyFromContinuation) {
TryInitiatingTransition(mPresContext, aFrame->GetContent(),
oldContext, &newContext);
}
#endif
// Ensure the new context ends up resolving all the structs the old
// context resolved.
if (!copyFromContinuation) {
newContext->EnsureSameStructsCached(oldContext);
}
aFrame->SetStyleContext(newContext);
nsIFrame::ChildListIterator lists(aFrame);
for (; !lists.IsDone(); lists.Next()) {
for (nsIFrame* child : lists.CurrentList()) {
// only do frames that are in flow
if (!(child->GetStateBits() & NS_FRAME_OUT_OF_FLOW) &&
child != providerChild) {
#ifdef DEBUG
if (child->IsPlaceholderFrame()) {
nsIFrame* outOfFlowFrame =
nsPlaceholderFrame::GetRealFrameForPlaceholder(child);
NS_ASSERTION(outOfFlowFrame, "no out-of-flow frame");
NS_ASSERTION(outOfFlowFrame != providerChild,
"Out of flow provider?");
}
#endif
ReparentStyleContext(child);
}
}
}
// If this frame is part of an IB split, then the style context of
// the next part of the split might be a child of our style context.
// Reparent its style context just in case one of our ancestors
// (split or not) hasn't done so already). It's not a problem to
// reparent the same frame twice because the "if (newContext !=
// oldContext)" check will prevent us from redoing work.
if ((aFrame->GetStateBits() & NS_FRAME_PART_OF_IBSPLIT) &&
!aFrame->GetPrevContinuation()) {
nsIFrame* sib = aFrame->GetProperty(nsIFrame::IBSplitSibling());
if (sib) {
ReparentStyleContext(sib);
}
}
// do additional contexts
int32_t contextIndex = 0;
for (nsStyleContext* oldExtraContext;
(oldExtraContext = aFrame->GetAdditionalStyleContext(contextIndex));
++contextIndex) {
RefPtr<nsStyleContext> newExtraContext;
newExtraContext = StyleSet()->
ReparentStyleContext(oldExtraContext,
newContext, nullptr);
if (newExtraContext) {
if (newExtraContext != oldExtraContext) {
// Ensure the new context ends up resolving all the structs the old
// context resolved.
newContext->EnsureSameStructsCached(oldContext);
}
aFrame->SetAdditionalStyleContext(contextIndex, newExtraContext);
}
}
#ifdef DEBUG
DebugVerifyStyleTree(aFrame);
#endif
}
}
return NS_OK;
}
ElementRestyler::ElementRestyler(nsPresContext* aPresContext,
nsIFrame* aFrame,
nsStyleChangeList* aChangeList,
nsChangeHint aHintsHandledByAncestors,
RestyleTracker& aRestyleTracker,
nsTArray<nsCSSSelector*>&
aSelectorsForDescendants,
TreeMatchContext& aTreeMatchContext,
nsTArray<nsIContent*>&
aVisibleKidsOfHiddenElement,
nsTArray<ContextToClear>& aContextsToClear,
nsTArray<RefPtr<nsStyleContext>>&
aSwappedStructOwners)
: mPresContext(aPresContext)
, mFrame(aFrame)
, mParentContent(nullptr)
// XXXldb Why does it make sense to use aParentContent? (See
// comment above assertion at start of ElementRestyler::Restyle.)
, mContent(mFrame->GetContent() ? mFrame->GetContent() : mParentContent)
, mChangeList(aChangeList)
, mHintsHandledByAncestors(aHintsHandledByAncestors)
, mHintsHandledBySelf(nsChangeHint(0))
, mRestyleTracker(aRestyleTracker)
, mSelectorsForDescendants(aSelectorsForDescendants)
, mTreeMatchContext(aTreeMatchContext)
, mResolvedChild(nullptr)
, mContextsToClear(aContextsToClear)
, mSwappedStructOwners(aSwappedStructOwners)
, mIsRootOfRestyle(true)
#ifdef ACCESSIBILITY
, mDesiredA11yNotifications(eSendAllNotifications)
, mKidsDesiredA11yNotifications(mDesiredA11yNotifications)
, mOurA11yNotification(eDontNotify)
, mVisibleKidsOfHiddenElement(aVisibleKidsOfHiddenElement)
#endif
#ifdef RESTYLE_LOGGING
, mLoggingDepth(aRestyleTracker.LoggingDepth() + 1)
#endif
{
MOZ_ASSERT_IF(mContent, !mContent->IsStyledByServo());
MOZ_ASSERT(!(mHintsHandledByAncestors & nsChangeHint_ReconstructFrame),
"why restyle descendants if we are reconstructing the frame for "
"an ancestor?");
}
ElementRestyler::ElementRestyler(const ElementRestyler& aParentRestyler,
nsIFrame* aFrame,
uint32_t aConstructorFlags)
: mPresContext(aParentRestyler.mPresContext)
, mFrame(aFrame)
, mParentContent(aParentRestyler.mContent)
// XXXldb Why does it make sense to use aParentContent? (See
// comment above assertion at start of ElementRestyler::Restyle.)
, mContent(mFrame->GetContent() ? mFrame->GetContent() : mParentContent)
, mChangeList(aParentRestyler.mChangeList)
, mHintsHandledByAncestors(
// Note that when FOR_OUT_OF_FLOW_CHILD, the out-of-flow may not be a
// geometric descendant of the frame where we started the reresolve.
// Therefore, even if mHintsHandledByAncestors already includes
// nsChangeHint_AllReflowHints/ we don't want to pass that on to the
// out-of-flow reresolve, since that can lead to the out-of-flow not
// getting reflowed when it should be (eg a reresolve starting at <body>
// that involves reflowing the <body> would miss reflowing fixed-pos
// nodes that also need reflow). In the cases when the out-of-flow _is_
// a geometric descendant of a frame we already have a reflow hint
// for, reflow coalescing should keep us from doing the work twice.
(aParentRestyler.mHintsHandledByAncestors |
aParentRestyler.mHintsHandledBySelf) &
((aConstructorFlags & FOR_OUT_OF_FLOW_CHILD) ?
~nsChangeHint_AllReflowHints : ~nsChangeHint(0)))
, mHintsHandledBySelf(nsChangeHint(0))
, mRestyleTracker(aParentRestyler.mRestyleTracker)
, mSelectorsForDescendants(aParentRestyler.mSelectorsForDescendants)
, mTreeMatchContext(aParentRestyler.mTreeMatchContext)
, mResolvedChild(nullptr)
, mContextsToClear(aParentRestyler.mContextsToClear)
, mSwappedStructOwners(aParentRestyler.mSwappedStructOwners)
, mIsRootOfRestyle(false)
#ifdef ACCESSIBILITY
, mDesiredA11yNotifications(aParentRestyler.mKidsDesiredA11yNotifications)
, mKidsDesiredA11yNotifications(mDesiredA11yNotifications)
, mOurA11yNotification(eDontNotify)
, mVisibleKidsOfHiddenElement(aParentRestyler.mVisibleKidsOfHiddenElement)
#endif
#ifdef RESTYLE_LOGGING
, mLoggingDepth(aParentRestyler.mLoggingDepth + 1)
#endif
{
MOZ_ASSERT_IF(mContent, !mContent->IsStyledByServo());
MOZ_ASSERT(!(mHintsHandledByAncestors & nsChangeHint_ReconstructFrame),
"why restyle descendants if we are reconstructing the frame for "
"an ancestor?");
}
ElementRestyler::ElementRestyler(ParentContextFromChildFrame,
const ElementRestyler& aParentRestyler,
nsIFrame* aFrame)
: mPresContext(aParentRestyler.mPresContext)
, mFrame(aFrame)
, mParentContent(aParentRestyler.mParentContent)
// XXXldb Why does it make sense to use aParentContent? (See
// comment above assertion at start of ElementRestyler::Restyle.)
, mContent(mFrame->GetContent() ? mFrame->GetContent() : mParentContent)
, mChangeList(aParentRestyler.mChangeList)
, mHintsHandledByAncestors(aParentRestyler.mHintsHandledByAncestors |
aParentRestyler.mHintsHandledBySelf)
, mHintsHandledBySelf(nsChangeHint(0))
, mRestyleTracker(aParentRestyler.mRestyleTracker)
, mSelectorsForDescendants(aParentRestyler.mSelectorsForDescendants)
, mTreeMatchContext(aParentRestyler.mTreeMatchContext)
, mResolvedChild(nullptr)
, mContextsToClear(aParentRestyler.mContextsToClear)
, mSwappedStructOwners(aParentRestyler.mSwappedStructOwners)
, mIsRootOfRestyle(false)
#ifdef ACCESSIBILITY
, mDesiredA11yNotifications(aParentRestyler.mDesiredA11yNotifications)
, mKidsDesiredA11yNotifications(mDesiredA11yNotifications)
, mOurA11yNotification(eDontNotify)
, mVisibleKidsOfHiddenElement(aParentRestyler.mVisibleKidsOfHiddenElement)
#endif
#ifdef RESTYLE_LOGGING
, mLoggingDepth(aParentRestyler.mLoggingDepth + 1)
#endif
{
MOZ_ASSERT_IF(mContent, !mContent->IsStyledByServo());
// We would assert here that we're not restyling a child provider frame if
// mHintsHandledByAncestors includes nsChangeHint_ReconstructFrame, but
// we do actually do this if the ReconstructFrame hint came from the
// RestyleTracker, rather than generated from CalcDifference. (We could
// even try to avoid restyling the child provider frame, by returning
// early in ElementRestyler::Restyle if we grab out a ReconstructFrame
// hint from the RestyleTracker, but it's trickier to verify its correctness
// with all of the tree patching that happens currently, so for now we just
// skip the assertion.)
}
ElementRestyler::ElementRestyler(nsPresContext* aPresContext,
nsIContent* aContent,
nsStyleChangeList* aChangeList,
nsChangeHint aHintsHandledByAncestors,
RestyleTracker& aRestyleTracker,
nsTArray<nsCSSSelector*>& aSelectorsForDescendants,
TreeMatchContext& aTreeMatchContext,
nsTArray<nsIContent*>&
aVisibleKidsOfHiddenElement,
nsTArray<ContextToClear>& aContextsToClear,
nsTArray<RefPtr<nsStyleContext>>&
aSwappedStructOwners)
: mPresContext(aPresContext)
, mFrame(nullptr)
, mParentContent(nullptr)
, mContent(aContent)
, mChangeList(aChangeList)
, mHintsHandledByAncestors(aHintsHandledByAncestors)
, mHintsHandledBySelf(nsChangeHint(0))
, mRestyleTracker(aRestyleTracker)
, mSelectorsForDescendants(aSelectorsForDescendants)
, mTreeMatchContext(aTreeMatchContext)
, mResolvedChild(nullptr)
, mContextsToClear(aContextsToClear)
, mSwappedStructOwners(aSwappedStructOwners)
, mIsRootOfRestyle(true)
#ifdef ACCESSIBILITY
, mDesiredA11yNotifications(eSendAllNotifications)
, mKidsDesiredA11yNotifications(mDesiredA11yNotifications)
, mOurA11yNotification(eDontNotify)
, mVisibleKidsOfHiddenElement(aVisibleKidsOfHiddenElement)
#endif
{
MOZ_ASSERT(!(mHintsHandledByAncestors & nsChangeHint_ReconstructFrame),
"why restyle descendants if we are reconstructing the frame for "
"an ancestor?");
}
void
ElementRestyler::CaptureChange(nsStyleContext* aOldContext,
nsStyleContext* aNewContext,
nsChangeHint aChangeToAssume,
uint32_t* aEqualStructs,
uint32_t* aSamePointerStructs)
{
static_assert(nsStyleStructID_Length <= 32,
"aEqualStructs is not big enough");
// Check some invariants about replacing one style context with another.
NS_ASSERTION(aOldContext->GetPseudo() == aNewContext->GetPseudo(),
"old and new style contexts should have the same pseudo");
NS_ASSERTION(aOldContext->GetPseudoType() == aNewContext->GetPseudoType(),
"old and new style contexts should have the same pseudo");
nsChangeHint ourChange =
aOldContext->CalcStyleDifference(aNewContext,
aEqualStructs,
aSamePointerStructs);
NS_ASSERTION(!(ourChange & nsChangeHint_AllReflowHints) ||
(ourChange & nsChangeHint_NeedReflow),
"Reflow hint bits set without actually asking for a reflow");
LOG_RESTYLE("CaptureChange, ourChange = %s, aChangeToAssume = %s",
GeckoRestyleManager::ChangeHintToString(ourChange).get(),
GeckoRestyleManager::ChangeHintToString(aChangeToAssume).get());
LOG_RESTYLE_INDENT();
// nsChangeHint_UpdateEffects is not handled for descendants, but it can be
// set due to changes in inherited properties (fill and stroke). Avoid
// propagating it into text nodes.
if ((ourChange & nsChangeHint_UpdateEffects) &&
mContent && !mContent->IsElement()) {
ourChange &= ~nsChangeHint_UpdateEffects;
}
ourChange |= aChangeToAssume;
nsChangeHint changeToAppend =
NS_RemoveSubsumedHints(ourChange, mHintsHandledByAncestors);
// mHintsHandledBySelf starts off as nsChangeHint(0), when restyling a given
// frame, and accumulates change hints for each same-style-continuation and
// {ib}-split sibling following it. Most of the time, any subsequent frames
// we restyle with this ElementRestyler will generate exactly the same
// |changeToAppend| that we have already stored in mHintsHandledBySelf. If
// we generate some hints that weren't handled by an earler same-style-
// continuation or {ib}-split sibling, then we record the entire
// |changeToAppend| value. (We could use something like
// NS_RemoveSubsumedHints, but aimed at removing hints handled only for the
// current element instead. However, we should probably just fix these rare
// cases as part of bug 918064.)
if (!NS_IsHintSubset(changeToAppend, mHintsHandledBySelf)) {
mHintsHandledBySelf |= changeToAppend;
if (!(ourChange & nsChangeHint_ReconstructFrame) || mContent) {
LOG_RESTYLE("appending change %s",
RestyleManager::ChangeHintToString(changeToAppend).get());
mChangeList->AppendChange(mFrame, mContent, changeToAppend);
} else {
LOG_RESTYLE("ignoring ReconstructFrame change with no content");
}
} else {
LOG_RESTYLE("change has already been handled");
}
}
class MOZ_RAII AutoSelectorArrayTruncater final
{
public:
explicit AutoSelectorArrayTruncater(
nsTArray<nsCSSSelector*>& aSelectorsForDescendants)
: mSelectorsForDescendants(aSelectorsForDescendants)
, mOriginalLength(aSelectorsForDescendants.Length())
{
}
~AutoSelectorArrayTruncater()
{
mSelectorsForDescendants.TruncateLength(mOriginalLength);
}
private:
nsTArray<nsCSSSelector*>& mSelectorsForDescendants;
size_t mOriginalLength;
};
/**
* Called when we are stopping a restyle with eRestyle_SomeDescendants, to
* search for descendants that match any of the selectors in
* mSelectorsForDescendants. If the element does match one of the selectors,
* we cause it to be restyled with eRestyle_Self.
*
* We traverse down the frame tree (and through the flattened content tree
* when we find undisplayed content) unless we find an element that (a) already
* has a pending restyle, or (b) does not have a pending restyle but does match
* one of the selectors in mSelectorsForDescendants. For (a), we add the
* current mSelectorsForDescendants into the existing restyle data, and for (b)
* we add a new pending restyle with that array. So in both cases, when we
* come to restyling this element back up in ProcessPendingRestyles, we will
* again find the eRestyle_SomeDescendants hint and its selectors array.
*
* This ensures that we don't visit descendant elements and check them
* against mSelectorsForDescendants more than once.
*/
void
ElementRestyler::ConditionallyRestyleChildren()
{
MOZ_ASSERT(mContent == mFrame->GetContent());
if (!mContent->IsElement() || mSelectorsForDescendants.IsEmpty()) {
return;
}
Element* element = mContent->AsElement();
LOG_RESTYLE("traversing descendants of frame %s (with element %s) to "
"propagate eRestyle_SomeDescendants for these %d selectors:",
FrameTagToString(mFrame).get(),
ElementTagToString(element).get(),
int(mSelectorsForDescendants.Length()));
LOG_RESTYLE_INDENT();
#ifdef RESTYLE_LOGGING
for (nsCSSSelector* sel : mSelectorsForDescendants) {
LOG_RESTYLE("%s", sel->RestrictedSelectorToString().get());
}
#endif
Element* restyleRoot = mRestyleTracker.FindClosestRestyleRoot(element);
ConditionallyRestyleChildren(mFrame, restyleRoot);
}
void
ElementRestyler::ConditionallyRestyleChildren(nsIFrame* aFrame,
Element* aRestyleRoot)
{
MOZ_ASSERT(aFrame->GetContent());
MOZ_ASSERT(aFrame->GetContent()->IsElement());
MOZ_ASSERT(!aFrame->GetContent()->IsStyledByServo());
ConditionallyRestyleUndisplayedDescendants(aFrame, aRestyleRoot);
ConditionallyRestyleContentChildren(aFrame, aRestyleRoot);
}
// The structure of this method parallels RestyleContentChildren.
// If you update this method, you probably want to update that one too.
void
ElementRestyler::ConditionallyRestyleContentChildren(nsIFrame* aFrame,
Element* aRestyleRoot)
{
MOZ_ASSERT(aFrame->GetContent());
MOZ_ASSERT(aFrame->GetContent()->IsElement());
MOZ_ASSERT(!aFrame->GetContent()->IsStyledByServo());
if (aFrame->GetContent()->HasFlag(mRestyleTracker.RootBit())) {
aRestyleRoot = aFrame->GetContent()->AsElement();
}
for (nsIFrame* f = aFrame; f;
f = GeckoRestyleManager::GetNextContinuationWithSameStyle(f, f->StyleContext())) {
nsIFrame::ChildListIterator lists(f);
for (; !lists.IsDone(); lists.Next()) {
for (nsIFrame* child : lists.CurrentList()) {
// Out-of-flows are reached through their placeholders. Continuations
// and block-in-inline splits are reached through those chains.
if (!(child->GetStateBits() & NS_FRAME_OUT_OF_FLOW) &&
!GetPrevContinuationWithSameStyle(child)) {
// only do frames that are in flow
if (child->IsPlaceholderFrame()) { // placeholder
// get out of flow frame and recur there
nsIFrame* outOfFlowFrame =
nsPlaceholderFrame::GetRealFrameForPlaceholder(child);
// |nsFrame::GetParentStyleContext| checks being out
// of flow so that this works correctly.
do {
if (GetPrevContinuationWithSameStyle(outOfFlowFrame)) {
continue;
}
if (!ConditionallyRestyle(outOfFlowFrame, aRestyleRoot)) {
ConditionallyRestyleChildren(outOfFlowFrame, aRestyleRoot);
}
} while ((outOfFlowFrame = outOfFlowFrame->GetNextContinuation()));
} else { // regular child frame
if (child != mResolvedChild) {
if (!ConditionallyRestyle(child, aRestyleRoot)) {
ConditionallyRestyleChildren(child, aRestyleRoot);
}
}
}
}
}
}
}
}
// The structure of this method parallels RestyleUndisplayedDescendants.
// If you update this method, you probably want to update that one too.
void
ElementRestyler::ConditionallyRestyleUndisplayedDescendants(
nsIFrame* aFrame,
Element* aRestyleRoot)
{
nsIContent* undisplayedParent;
if (MustCheckUndisplayedContent(aFrame, undisplayedParent)) {
DoConditionallyRestyleUndisplayedDescendants(undisplayedParent,
aRestyleRoot);
}
}
// The structure of this method parallels DoRestyleUndisplayedDescendants.
// If you update this method, you probably want to update that one too.
void
ElementRestyler::DoConditionallyRestyleUndisplayedDescendants(
nsIContent* aParent,
Element* aRestyleRoot)
{
nsCSSFrameConstructor* fc = mPresContext->FrameConstructor();
UndisplayedNode* nodes = fc->GetAllUndisplayedContentIn(aParent);
ConditionallyRestyleUndisplayedNodes(nodes, aParent,
StyleDisplay::None, aRestyleRoot);
nodes = fc->GetAllDisplayContentsIn(aParent);
ConditionallyRestyleUndisplayedNodes(nodes, aParent,
StyleDisplay::Contents, aRestyleRoot);
}
// The structure of this method parallels RestyleUndisplayedNodes.
// If you update this method, you probably want to update that one too.
void
ElementRestyler::ConditionallyRestyleUndisplayedNodes(
UndisplayedNode* aUndisplayed,
nsIContent* aUndisplayedParent,
const StyleDisplay aDisplay,
Element* aRestyleRoot)
{
MOZ_ASSERT(aDisplay == StyleDisplay::None ||
aDisplay == StyleDisplay::Contents);
if (!aUndisplayed) {
return;
}
if (aUndisplayedParent &&
aUndisplayedParent->IsElement() &&
aUndisplayedParent->HasFlag(mRestyleTracker.RootBit())) {
MOZ_ASSERT(!aUndisplayedParent->IsStyledByServo());
aRestyleRoot = aUndisplayedParent->AsElement();
}
for (UndisplayedNode* undisplayed = aUndisplayed; undisplayed;
undisplayed = undisplayed->getNext()) {
if (!undisplayed->mContent->IsElement()) {
continue;
}
Element* element = undisplayed->mContent->AsElement();
if (!ConditionallyRestyle(element, aRestyleRoot)) {
if (aDisplay == StyleDisplay::None) {
ConditionallyRestyleContentDescendants(element, aRestyleRoot);
} else { // StyleDisplay::Contents
DoConditionallyRestyleUndisplayedDescendants(element, aRestyleRoot);
}
}
}
}
void
ElementRestyler::ConditionallyRestyleContentDescendants(Element* aElement,
Element* aRestyleRoot)
{
MOZ_ASSERT(!aElement->IsStyledByServo());
if (aElement->HasFlag(mRestyleTracker.RootBit())) {
aRestyleRoot = aElement;
}
FlattenedChildIterator it(aElement);
for (nsIContent* n = it.GetNextChild(); n; n = it.GetNextChild()) {
if (n->IsElement()) {
Element* e = n->AsElement();
if (!ConditionallyRestyle(e, aRestyleRoot)) {
ConditionallyRestyleContentDescendants(e, aRestyleRoot);
}
}
}
}
bool
ElementRestyler::ConditionallyRestyle(nsIFrame* aFrame, Element* aRestyleRoot)
{
MOZ_ASSERT(aFrame->GetContent());
if (!aFrame->GetContent()->IsElement()) {
return true;
}
return ConditionallyRestyle(aFrame->GetContent()->AsElement(), aRestyleRoot);
}
bool
ElementRestyler::ConditionallyRestyle(Element* aElement, Element* aRestyleRoot)
{
MOZ_ASSERT(!aElement->IsStyledByServo());
LOG_RESTYLE("considering element %s for eRestyle_SomeDescendants",
ElementTagToString(aElement).get());
LOG_RESTYLE_INDENT();
if (aElement->HasFlag(mRestyleTracker.RootBit())) {
aRestyleRoot = aElement;
}
if (mRestyleTracker.HasRestyleData(aElement)) {
nsRestyleHint rshint = eRestyle_SomeDescendants;
if (SelectorMatchesForRestyle(aElement)) {
LOG_RESTYLE("element has existing restyle data and matches a selector");
rshint |= eRestyle_Self;
} else {
LOG_RESTYLE("element has existing restyle data but doesn't match selectors");
}
RestyleHintData data;
data.mSelectorsForDescendants = mSelectorsForDescendants;
mRestyleTracker.AddPendingRestyle(aElement, rshint, nsChangeHint(0), &data,
Some(aRestyleRoot));
return true;
}
if (SelectorMatchesForRestyle(aElement)) {
LOG_RESTYLE("element has no restyle data but matches a selector");
RestyleHintData data;
data.mSelectorsForDescendants = mSelectorsForDescendants;
mRestyleTracker.AddPendingRestyle(aElement,
eRestyle_Self | eRestyle_SomeDescendants,
nsChangeHint(0), &data,
Some(aRestyleRoot));
return true;
}
return false;
}
bool
ElementRestyler::MustCheckUndisplayedContent(nsIFrame* aFrame,
nsIContent*& aUndisplayedParent)
{
// When the root element is display:none, we still construct *some*
// frames that have the root element as their mContent, down to the
// DocElementContainingBlock.
if (aFrame->StyleContext()->GetPseudo()) {
aUndisplayedParent = nullptr;
return aFrame == mPresContext->FrameConstructor()->
GetDocElementContainingBlock();
}
aUndisplayedParent = aFrame->GetContent();
return !!aUndisplayedParent;
}
/**
* Helper for MoveStyleContextsForChildren, below. Appends the style
* contexts to be moved to mFrame's current (new) style context to
* aContextsToMove.
*/
bool
ElementRestyler::MoveStyleContextsForContentChildren(
nsIFrame* aParent,
nsStyleContext* aOldContext,
nsTArray<nsStyleContext*>& aContextsToMove)
{
nsIFrame::ChildListIterator lists(aParent);
for (; !lists.IsDone(); lists.Next()) {
for (nsIFrame* child : lists.CurrentList()) {
// Bail out if we have out-of-flow frames.
// FIXME: It might be safe to just continue here instead of bailing out.
if (child->GetStateBits() & NS_FRAME_OUT_OF_FLOW) {
return false;
}
if (GetPrevContinuationWithSameStyle(child)) {
continue;
}
// Bail out if we have placeholder frames.
// FIXME: It is probably safe to just continue here instead of bailing out.
if (child->IsPlaceholderFrame()) {
return false;
}
nsStyleContext* sc = child->StyleContext();
if (sc->GetParent() != aOldContext) {
return false;
}
LayoutFrameType type = child->Type();
if (type == LayoutFrameType::Letter || type == LayoutFrameType::Line) {
return false;
}
if (sc->HasChildThatUsesGrandancestorStyle()) {
// XXX Not sure if we need this?
return false;
}
nsIAtom* pseudoTag = sc->GetPseudo();
if (pseudoTag && !nsCSSAnonBoxes::IsNonElement(pseudoTag)) {
return false;
}
aContextsToMove.AppendElement(sc);
}
}
return true;
}
/**
* Traverses to child elements (through the current frame's same style
* continuations, just like RestyleChildren does) and moves any style context
* for those children to be parented under mFrame's current (new) style
* context.
*
* False is returned if it encounters any conditions on the child elements'
* frames and style contexts that means it is impossible to move a
* style context. If false is returned, no style contexts will have been
* moved.
*/
bool
ElementRestyler::MoveStyleContextsForChildren(nsStyleContext* aOldContext)
{
// Bail out if there are undisplayed or display:contents children.
// FIXME: We could get this to work if we need to.
nsIContent* undisplayedParent;
if (MustCheckUndisplayedContent(mFrame, undisplayedParent)) {
nsCSSFrameConstructor* fc = mPresContext->FrameConstructor();
if (fc->GetAllUndisplayedContentIn(undisplayedParent) ||
fc->GetAllDisplayContentsIn(undisplayedParent)) {
return false;
}
}
nsTArray<nsStyleContext*> contextsToMove;
MOZ_ASSERT(!MustReframeForBeforePseudo(),
"shouldn't need to reframe ::before as we would have had "
"eRestyle_Subtree and wouldn't get in here");
DebugOnly<nsIFrame*> lastContinuation;
for (nsIFrame* f = mFrame; f;
f = GeckoRestyleManager::GetNextContinuationWithSameStyle(f, f->StyleContext())) {
lastContinuation = f;
if (!MoveStyleContextsForContentChildren(f, aOldContext, contextsToMove)) {
return false;
}
}
MOZ_ASSERT(!MustReframeForAfterPseudo(lastContinuation),
"shouldn't need to reframe ::after as we would have had "
"eRestyle_Subtree and wouldn't get in here");
nsStyleContext* newParent = mFrame->StyleContext();
for (nsStyleContext* child : contextsToMove) {
// We can have duplicate entries in contextsToMove, so only move
// each style context once.
if (child->GetParent() != newParent) {
child->MoveTo(newParent);
}
}
return true;
}
/**
* Recompute style for mFrame (which should not have a prev continuation
* with the same style), all of its next continuations with the same
* style, and all ib-split siblings of the same type (either block or
* inline, skipping the intermediates of the other type) and accumulate
* changes into mChangeList given that mHintsHandledByAncestors is already
* accumulated for an ancestor.
* mParentContent is the content node used to resolve the parent style
* context. This means that, for pseudo-elements, it is the content
* that should be used for selector matching (rather than the fake
* content node attached to the frame).
*/
void
ElementRestyler::Restyle(nsRestyleHint aRestyleHint)
{
// It would be nice if we could make stronger assertions here; they
// would let us simplify the ?: expressions below setting |content|
// and |pseudoContent| in sensible ways as well as making what
// |content| and |pseudoContent| mean, and their relationship to
// |mFrame->GetContent()|, make more sense. However, we can't,
// because of frame trees like the one in
// https://bugzilla.mozilla.org/show_bug.cgi?id=472353#c14 . Once we
// fix bug 242277 we should be able to make this make more sense.
NS_ASSERTION(mFrame->GetContent() || !mParentContent ||
!mParentContent->GetParent(),
"frame must have content (unless at the top of the tree)");
MOZ_ASSERT(mPresContext == mFrame->PresContext(), "pres contexts match");
NS_ASSERTION(!GetPrevContinuationWithSameStyle(mFrame),
"should not be trying to restyle this frame separately");
MOZ_ASSERT(!(aRestyleHint & eRestyle_LaterSiblings),
"eRestyle_LaterSiblings must not be part of aRestyleHint");
AutoDisplayContentsAncestorPusher adcp(mTreeMatchContext, mPresContext,
mFrame->GetContent() ? mFrame->GetContent()->GetParent() : nullptr);
AutoSelectorArrayTruncater asat(mSelectorsForDescendants);
// List of descendant elements of mContent we know we will eventually need to
// restyle. Before we return from this function, we call
// RestyleTracker::AddRestyleRootsIfAwaitingRestyle to ensure they get
// restyled in RestyleTracker::DoProcessRestyles.
nsTArray<RefPtr<Element>> descendants;
nsRestyleHint hintToRestore = nsRestyleHint(0);
RestyleHintData hintDataToRestore;
if (mContent && mContent->IsElement() &&
// If we're resolving from the root of the frame tree (which
// we do when mDoRebuildAllStyleData), we need to avoid getting the
// root's restyle data until we get to its primary frame, since
// it's the primary frame that has the styles for the root element
// (rather than the ancestors of the primary frame whose mContent
// is the root node but which have different styles). If we use
// up the hint for one of the ancestors that we hit first, then
// we'll fail to do the restyling we need to do.
// Likewise, if we're restyling something with two nested frames,
// and we post a restyle from the transition manager while
// computing style for the outer frame (to be computed after the
// descendants have been resolved), we don't want to consume it
// for the inner frame.
mContent->GetPrimaryFrame() == mFrame) {
mContent->OwnerDoc()->FlushPendingLinkUpdates();
nsAutoPtr<RestyleTracker::RestyleData> restyleData;
if (mRestyleTracker.GetRestyleData(mContent->AsElement(), restyleData)) {
nsChangeHint changeToAppend =
NS_RemoveSubsumedHints(restyleData->mChangeHint,
mHintsHandledByAncestors);
// See the comment in CaptureChange about why we use NS_IsHintSubset here.
if (!NS_IsHintSubset(changeToAppend, mHintsHandledBySelf)) {
mHintsHandledBySelf |= changeToAppend;
mChangeList->AppendChange(mFrame, mContent, changeToAppend);
}
mSelectorsForDescendants.AppendElements(
restyleData->mRestyleHintData.mSelectorsForDescendants);
hintToRestore = restyleData->mRestyleHint;
hintDataToRestore = Move(restyleData->mRestyleHintData);
aRestyleHint = nsRestyleHint(aRestyleHint | restyleData->mRestyleHint);
descendants.SwapElements(restyleData->mDescendants);
}
}
// If we are restyling this frame with eRestyle_Self or weaker hints,
// we restyle children with nsRestyleHint(0). But we pass the
// eRestyle_ForceDescendants flag down too.
nsRestyleHint childRestyleHint =
nsRestyleHint(aRestyleHint & (eRestyle_SomeDescendants |
eRestyle_Subtree |
eRestyle_ForceDescendants));
RefPtr<nsStyleContext> oldContext = mFrame->StyleContext();
nsTArray<SwapInstruction> swaps;
// TEMPORARY (until bug 918064): Call RestyleSelf for each
// continuation or block-in-inline sibling.
// We must make a single decision on how to process this frame and
// its descendants, yet RestyleSelf might return different RestyleResult
// values for the different same-style continuations. |result| is our
// overall decision.
RestyleResult result = RestyleResult::eNone;
uint32_t swappedStructs = 0;
nsRestyleHint thisRestyleHint = aRestyleHint;
bool haveMoreContinuations = false;
for (nsIFrame* f = mFrame; f; ) {
RestyleResult thisResult =
RestyleSelf(f, thisRestyleHint, &swappedStructs, swaps);
if (thisResult != RestyleResult::eStop) {
// Calls to RestyleSelf for later same-style continuations must not
// return RestyleResult::eStop, so pass eRestyle_Force in to them.
thisRestyleHint = nsRestyleHint(thisRestyleHint | eRestyle_Force);
if (result == RestyleResult::eStop) {
// We received RestyleResult::eStop for earlier same-style
// continuations, and RestyleResult::eStopWithStyleChange or
// RestyleResult::eContinue(AndForceDescendants) for this one; go
// back and force-restyle the earlier continuations.
result = thisResult;
f = mFrame;
continue;
}
}
if (thisResult > result) {
// We take the highest RestyleResult value when working out what to do
// with this frame and its descendants. Higher RestyleResult values
// represent a superset of the work done by lower values.
result = thisResult;
}
f = GeckoRestyleManager::GetNextContinuationWithSameStyle(
f, oldContext, &haveMoreContinuations);
}
// 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.
//
// Although we only expect this code path to be called when computed style
// is not changing, we can sometimes reach this at the end of a transition
// when the animated style is being removed. Since
// AddLayerChangesForAnimation checks if mFrame has a transform style or not,
// we need to call it *after* calling RestyleSelf to ensure the animated
// transform has been removed first.
RestyleManager::AddLayerChangesForAnimation(mFrame, mContent, *mChangeList);
if (haveMoreContinuations && hintToRestore) {
// If we have more continuations with different style (e.g., because
// we're inside a ::first-letter or ::first-line), put the restyle
// hint back.
mRestyleTracker.AddPendingRestyleToTable(mContent->AsElement(),
hintToRestore, nsChangeHint(0));
}
if (result == RestyleResult::eStop) {
MOZ_ASSERT(mFrame->StyleContext() == oldContext,
"frame should have been left with its old style context");
nsIFrame* unused;
nsStyleContext* newParent = mFrame->GetParentStyleContext(&unused);
if (oldContext->GetParent() != newParent) {
// If we received RestyleResult::eStop, then the old style context was
// left on mFrame. Since we ended up restyling our parent, change
// this old style context to point to its new parent.
LOG_RESTYLE("moving style context %p from old parent %p to new parent %p",
oldContext.get(), oldContext->GetParent(), newParent);
// We keep strong references to the new parent around until the end
// of the restyle, in case:
// (a) we swapped structs between the old and new parent,
// (b) some descendants of the old parent are not getting restyled
// (which is the reason for the existence of
// ClearCachedInheritedStyleDataOnDescendants),
// (c) something under ProcessPendingRestyles (which notably is called
// *before* ClearCachedInheritedStyleDataOnDescendants is called
// on the old context) causes the new parent to be destroyed, thus
// destroying its owned structs, and
// (d) something under ProcessPendingRestyles then wants to use of those
// now destroyed structs (through the old parent's descendants).
mSwappedStructOwners.AppendElement(newParent);
oldContext->MoveTo(newParent);
}
// Send the accessibility notifications that RestyleChildren otherwise
// would have sent.
if (!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame)) {
InitializeAccessibilityNotifications(mFrame->StyleContext());
SendAccessibilityNotifications();
}
mRestyleTracker.AddRestyleRootsIfAwaitingRestyle(descendants);
if (aRestyleHint & eRestyle_SomeDescendants) {
ConditionallyRestyleChildren();
}
return;
}
if (result == RestyleResult::eStopWithStyleChange &&
!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame)) {
MOZ_ASSERT(mFrame->StyleContext() != oldContext,
"RestyleResult::eStopWithStyleChange should only be returned "
"if we got a new style context or we will reconstruct");
MOZ_ASSERT(swappedStructs == 0,
"should have ensured we didn't swap structs when "
"returning RestyleResult::eStopWithStyleChange");
// We need to ensure that all of the frames that inherit their style
// from oldContext are able to be moved across to newContext.
// MoveStyleContextsForChildren will check for certain conditions
// to ensure it is safe to move all of the relevant child style
// contexts to newContext. If these conditions fail, it will
// return false, and we'll have to continue restyling.
const bool canStop = MoveStyleContextsForChildren(oldContext);
if (canStop) {
// Send the accessibility notifications that RestyleChildren otherwise
// would have sent.
if (!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame)) {
InitializeAccessibilityNotifications(mFrame->StyleContext());
SendAccessibilityNotifications();
}
mRestyleTracker.AddRestyleRootsIfAwaitingRestyle(descendants);
if (aRestyleHint & eRestyle_SomeDescendants) {
ConditionallyRestyleChildren();
}
return;
}
// Turns out we couldn't stop restyling here. Process the struct
// swaps that RestyleSelf would've done had we not returned
// RestyleResult::eStopWithStyleChange.
for (SwapInstruction& swap : swaps) {
LOG_RESTYLE("swapping style structs between %p and %p",
swap.mOldContext.get(), swap.mNewContext.get());
swap.mOldContext->SwapStyleData(swap.mNewContext, swap.mStructsToSwap);
swappedStructs |= swap.mStructsToSwap;
}
swaps.Clear();
}
if (!swappedStructs) {
// If we swapped any structs from the old context, then we need to keep
// it alive until after the RestyleChildren call so that we can fix up
// its descendants' cached structs.
oldContext = nullptr;
}
if (result == RestyleResult::eContinueAndForceDescendants) {
childRestyleHint =
nsRestyleHint(childRestyleHint | eRestyle_ForceDescendants);
}
// No need to do this if we're planning to reframe already.
// It's also important to check mHintsHandledBySelf since we use
// mFrame->StyleContext(), which is out of date if mHintsHandledBySelf
// has a ReconstructFrame hint. Using an out of date style
// context could trigger assertions about mismatched rule trees.
if (!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame)) {
RestyleChildren(childRestyleHint);
}
if (oldContext && !oldContext->HasSingleReference()) {
// If we swapped some structs out of oldContext in the RestyleSelf call
// and after the RestyleChildren call we still have other strong references
// to it, we need to make ensure its descendants don't cache any of the
// structs that were swapped out.
//
// Much of the time we will not get in here; we do for example when the
// style context is shared with a later IB split sibling (which we won't
// restyle until a bit later) or if other code is holding a strong reference
// to the style context (as is done by nsTransformedTextRun objects, which
// can be referenced by a text frame's mTextRun longer than the frame's
// mStyleContext).
//
// Also, we don't want this style context to get any more uses by being
// returned from nsStyleContext::FindChildWithRules, so we add the
// NS_STYLE_INELIGIBLE_FOR_SHARING bit to it.
oldContext->SetIneligibleForSharing();
ContextToClear* toClear = mContextsToClear.AppendElement();
toClear->mStyleContext = Move(oldContext);
toClear->mStructs = swappedStructs;
}
mRestyleTracker.AddRestyleRootsIfAwaitingRestyle(descendants);
}
/**
* Depending on the details of the frame we are restyling or its old style
* context, we may or may not be able to stop restyling after this frame if
* we find we had no style changes.
*
* This function returns RestyleResult::eStop if it does not find any
* conditions that would preclude stopping restyling, and
* RestyleResult::eContinue if it does.
*/
void
ElementRestyler::ComputeRestyleResultFromFrame(nsIFrame* aSelf,
RestyleResult& aRestyleResult,
bool& aCanStopWithStyleChange)
{
// We can't handle situations where the primary style context of a frame
// has not had any style data changes, but its additional style contexts
// have, so we don't considering stopping if this frame has any additional
// style contexts.
if (aSelf->GetAdditionalStyleContext(0)) {
LOG_RESTYLE_CONTINUE("there are additional style contexts");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
// Each NAC element inherits from the first non-NAC ancestor, so child
// NAC may inherit from our parent instead of us. That means we can't
// cull traversal if our style context didn't change.
if (aSelf->GetContent() && aSelf->GetContent()->IsNativeAnonymous()) {
LOG_RESTYLE_CONTINUE("native anonymous content");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
// Style changes might have moved children between the two nsLetterFrames
// (the one matching ::first-letter and the one containing the rest of the
// content). Continue restyling to the children of the nsLetterFrame so
// that they get the correct style context parent. Similarly for
// nsLineFrames.
LayoutFrameType type = aSelf->Type();
if (type == LayoutFrameType::Letter) {
LOG_RESTYLE_CONTINUE("frame is a letter frame");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
if (type == LayoutFrameType::Line) {
LOG_RESTYLE_CONTINUE("frame is a line frame");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
// Some style computations depend not on the parent's style, but a grandparent
// or one the grandparent's ancestors. An example is an explicit 'inherit'
// value for align-self, where if the parent frame's value for the property is
// 'auto' we end up inheriting the computed value from the grandparent. We
// can't stop the restyling process on this frame (the one with 'auto', in
// this example), as the grandparent's computed value might have changed
// and we need to recompute the child's 'inherit' to that new value.
nsStyleContext* oldContext = aSelf->StyleContext();
if (oldContext->HasChildThatUsesGrandancestorStyle()) {
LOG_RESTYLE_CONTINUE("the old context uses grandancestor style");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
// We ignore all situations that involve :visited style.
if (oldContext->GetStyleIfVisited()) {
LOG_RESTYLE_CONTINUE("the old style context has StyleIfVisited");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
nsStyleContext* parentContext = oldContext->GetParent();
if (parentContext && parentContext->GetStyleIfVisited()) {
LOG_RESTYLE_CONTINUE("the old style context's parent has StyleIfVisited");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
// We also ignore frames for pseudos, as their style contexts have
// inheritance structures that do not match the frame inheritance
// structure. To avoid enumerating and checking all of the cases
// where we have this kind of inheritance, we keep restyling past
// pseudos.
nsIAtom* pseudoTag = oldContext->GetPseudo();
if (pseudoTag && !nsCSSAnonBoxes::IsNonElement(pseudoTag)) {
LOG_RESTYLE_CONTINUE("the old style context is for a pseudo");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
nsIFrame* parent = mFrame->GetParent();
if (parent) {
// Also if the parent has a pseudo, as this frame's style context will
// be inheriting from a grandparent frame's style context (or a further
// ancestor).
nsIAtom* parentPseudoTag = parent->StyleContext()->GetPseudo();
if (parentPseudoTag &&
parentPseudoTag != nsCSSAnonBoxes::firstLetterContinuation) {
MOZ_ASSERT(parentPseudoTag != nsCSSAnonBoxes::mozText,
"Style of text node should not be parent of anything");
MOZ_ASSERT(parentPseudoTag != nsCSSAnonBoxes::oofPlaceholder,
"Style of placeholder should not be parent of anything");
LOG_RESTYLE_CONTINUE("the old style context's parent is for a pseudo");
aRestyleResult = RestyleResult::eContinue;
// Parent style context pseudo-ness doesn't affect whether we can
// return RestyleResult::eStopWithStyleChange.
//
// If we had later conditions to check in this function, we would
// continue to check them, in case we set aCanStopWithStyleChange to
// false.
}
}
}
void
ElementRestyler::ComputeRestyleResultFromNewContext(nsIFrame* aSelf,
nsStyleContext* aNewContext,
RestyleResult& aRestyleResult,
bool& aCanStopWithStyleChange)
{
// If we've already determined that we must continue styling, we don't
// need to check anything.
if (aRestyleResult == RestyleResult::eContinue && !aCanStopWithStyleChange) {
return;
}
// Keep restyling if the new style context has any style-if-visted style, so
// that we can avoid the style context tree surgery having to deal to deal
// with visited styles.
if (aNewContext->GetStyleIfVisited()) {
LOG_RESTYLE_CONTINUE("the new style context has StyleIfVisited");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
// If link-related information has changed, or the pseudo for the frame has
// changed, or the new style context points to a different rule node, we can't
// leave the old style context on the frame.
nsStyleContext* oldContext = aSelf->StyleContext();
if (oldContext->IsLinkContext() != aNewContext->IsLinkContext() ||
oldContext->RelevantLinkVisited() != aNewContext->RelevantLinkVisited() ||
oldContext->GetPseudo() != aNewContext->GetPseudo() ||
oldContext->GetPseudoType() != aNewContext->GetPseudoType()) {
LOG_RESTYLE_CONTINUE("the old and new style contexts have different link/"
"visited/pseudo");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
if (oldContext->RuleNode() != aNewContext->RuleNode()) {
LOG_RESTYLE_CONTINUE("the old and new style contexts have different "
"rulenodes");
aRestyleResult = RestyleResult::eContinue;
// Continue to check other conditions if aCanStopWithStyleChange might
// still need to be set to false.
if (!aCanStopWithStyleChange) {
return;
}
}
// If the old and new style contexts differ in their
// NS_STYLE_HAS_TEXT_DECORATION_LINES or NS_STYLE_HAS_PSEUDO_ELEMENT_DATA
// bits, then we must keep restyling so that those new bit values are
// propagated.
if (oldContext->HasTextDecorationLines() !=
aNewContext->HasTextDecorationLines()) {
LOG_RESTYLE_CONTINUE("NS_STYLE_HAS_TEXT_DECORATION_LINES differs between old"
" and new style contexts");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
if (oldContext->HasPseudoElementData() !=
aNewContext->HasPseudoElementData()) {
LOG_RESTYLE_CONTINUE("NS_STYLE_HAS_PSEUDO_ELEMENT_DATA differs between old"
" and new style contexts");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
if (oldContext->ShouldSuppressLineBreak() !=
aNewContext->ShouldSuppressLineBreak()) {
LOG_RESTYLE_CONTINUE("NS_STYLE_SUPPRESS_LINEBREAK differs"
"between old and new style contexts");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
if (oldContext->IsInDisplayNoneSubtree() !=
aNewContext->IsInDisplayNoneSubtree()) {
LOG_RESTYLE_CONTINUE("NS_STYLE_IN_DISPLAY_NONE_SUBTREE differs between old"
" and new style contexts");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
if (oldContext->IsTextCombined() != aNewContext->IsTextCombined()) {
LOG_RESTYLE_CONTINUE("NS_STYLE_IS_TEXT_COMBINED differs between "
"old and new style contexts");
aRestyleResult = RestyleResult::eContinue;
aCanStopWithStyleChange = false;
return;
}
}
bool
ElementRestyler::SelectorMatchesForRestyle(Element* aElement)
{
if (!aElement) {
return false;
}
for (nsCSSSelector* selector : mSelectorsForDescendants) {
if (nsCSSRuleProcessor::RestrictedSelectorMatches(aElement, selector,
mTreeMatchContext)) {
return true;
}
}
return false;
}
bool
ElementRestyler::MustRestyleSelf(nsRestyleHint aRestyleHint,
Element* aElement)
{
return (aRestyleHint & (eRestyle_Self | eRestyle_Subtree)) ||
((aRestyleHint & eRestyle_SomeDescendants) &&
SelectorMatchesForRestyle(aElement));
}
bool
ElementRestyler::CanReparentStyleContext(nsRestyleHint aRestyleHint)
{
// If we had any restyle hints other than the ones listed below,
// which don't control whether the current frame/element needs
// a new style context by looking up a new rule node, or if
// we are reconstructing the entire rule tree, then we can't
// use ReparentStyleContext.
return !(aRestyleHint & ~(eRestyle_Force |
eRestyle_ForceDescendants |
eRestyle_SomeDescendants)) &&
!StyleSet()->IsInRuleTreeReconstruct();
}
// Returns true iff any rule node that is an ancestor-or-self of the
// two specified rule nodes, but which is not an ancestor of both,
// has any inherited style data. If false is returned, then we know
// that a change from one rule node to the other must not result in
// any change in inherited style data.
static bool
CommonInheritedStyleData(nsRuleNode* aRuleNode1, nsRuleNode* aRuleNode2)
{
if (aRuleNode1 == aRuleNode2) {
return true;
}
nsRuleNode* n1 = aRuleNode1->GetParent();
nsRuleNode* n2 = aRuleNode2->GetParent();
if (n1 == n2) {
// aRuleNode1 and aRuleNode2 sharing a parent is a common case, e.g.
// when modifying a style="" attribute. (We must null check GetRule()'s
// result since although we know the two parents are the same, it might
// be null, as in the case of the two rule nodes being roots of two
// different rule trees.)
if (aRuleNode1->GetRule() &&
aRuleNode1->GetRule()->MightMapInheritedStyleData()) {
return false;
}
if (aRuleNode2->GetRule() &&
aRuleNode2->GetRule()->MightMapInheritedStyleData()) {
return false;
}
return true;
}
// Compute the depths of aRuleNode1 and aRuleNode2.
int d1 = 0, d2 = 0;
while (n1) {
++d1;
n1 = n1->GetParent();
}
while (n2) {
++d2;
n2 = n2->GetParent();
}
// Make aRuleNode1 be the deeper node.
if (d2 > d1) {
std::swap(d1, d2);
std::swap(aRuleNode1, aRuleNode2);
}
// Check all of the rule nodes in the deeper branch until we reach
// the same depth as the shallower branch.
n1 = aRuleNode1;
n2 = aRuleNode2;
while (d1 > d2) {
nsIStyleRule* rule = n1->GetRule();
MOZ_ASSERT(rule, "non-root rule node should have a rule");
if (rule->MightMapInheritedStyleData()) {
return false;
}
n1 = n1->GetParent();
--d1;
}
// Check both branches simultaneously until we reach a common ancestor.
while (n1 != n2) {
MOZ_ASSERT(n1);
MOZ_ASSERT(n2);
// As above, we must null check GetRule()'s result since we won't find
// a common ancestor if the two rule nodes come from different rule trees,
// and thus we might reach the root (which has a null rule).
if (n1->GetRule() && n1->GetRule()->MightMapInheritedStyleData()) {
return false;
}
if (n2->GetRule() && n2->GetRule()->MightMapInheritedStyleData()) {
return false;
}
n1 = n1->GetParent();
n2 = n2->GetParent();
}
return true;
}
ElementRestyler::RestyleResult
ElementRestyler::RestyleSelf(nsIFrame* aSelf,
nsRestyleHint aRestyleHint,
uint32_t* aSwappedStructs,
nsTArray<SwapInstruction>& aSwaps)
{
MOZ_ASSERT(!(aRestyleHint & eRestyle_LaterSiblings),
"eRestyle_LaterSiblings must not be part of aRestyleHint");
// XXXldb get new context from prev-in-flow if possible, to avoid
// duplication. (Or should we just let |GetContext| handle that?)
// Getting the hint would be nice too, but that's harder.
// XXXbryner we may be able to avoid some of the refcounting goop here.
// We do need a reference to oldContext for the lifetime of this function, and it's possible
// that the frame has the last reference to it, so AddRef it here.
LOG_RESTYLE("RestyleSelf %s, aRestyleHint = %s",
FrameTagToString(aSelf).get(),
RestyleManager::RestyleHintToString(aRestyleHint).get());
LOG_RESTYLE_INDENT();
// Initially assume that it is safe to stop restyling.
//
// Throughout most of this function, we update the following two variables
// independently. |result| is set to RestyleResult::eContinue when we
// detect a condition that would not allow us to return RestyleResult::eStop.
// |canStopWithStyleChange| is set to false when we detect a condition
// that would not allow us to return RestyleResult::eStopWithStyleChange.
//
// Towards the end of this function, we reconcile these two variables --
// if |canStopWithStyleChange| is true, we convert |result| into
// RestyleResult::eStopWithStyleChange.
RestyleResult result = RestyleResult::eStop;
bool canStopWithStyleChange = true;
if (aRestyleHint & ~eRestyle_SomeDescendants) {
// If we are doing any restyling of the current element, or if we're
// forced to continue, we must.
result = RestyleResult::eContinue;
// If we have to restyle children, we can't return
// RestyleResult::eStopWithStyleChange.
if (aRestyleHint & (eRestyle_Subtree | eRestyle_Force |
eRestyle_ForceDescendants)) {
canStopWithStyleChange = false;
}
}
// We only consider returning RestyleResult::eStopWithStyleChange if this
// is the root of the restyle. (Otherwise, we would need to track the
// style changes of the ancestors we just restyled.)
if (!mIsRootOfRestyle) {
canStopWithStyleChange = false;
}
// Look at the frame and its current style context for conditions
// that would change our RestyleResult.
ComputeRestyleResultFromFrame(aSelf, result, canStopWithStyleChange);
nsChangeHint assumeDifferenceHint = nsChangeHint(0);
RefPtr<nsStyleContext> oldContext = aSelf->StyleContext();
nsStyleSet* styleSet = StyleSet();
#ifdef ACCESSIBILITY
mWasFrameVisible = nsIPresShell::IsAccessibilityActive() ?
oldContext->StyleVisibility()->IsVisible() : false;
#endif
nsIAtom* const pseudoTag = oldContext->GetPseudo();
const CSSPseudoElementType pseudoType = oldContext->GetPseudoType();
// Get the frame providing the parent style context. If it is a
// child, then resolve the provider first.
nsIFrame* providerFrame;
nsStyleContext* parentContext = aSelf->GetParentStyleContext(&providerFrame);
bool isChild = providerFrame && providerFrame->GetParent() == aSelf;
if (isChild) {
MOZ_ASSERT(providerFrame->GetContent() == aSelf->GetContent(),
"Postcondition for GetParentStyleContext() violated. "
"That means we need to add the current element to the "
"ancestor filter.");
// resolve the provider here (before aSelf below).
LOG_RESTYLE("resolving child provider frame");
// assumeDifferenceHint forces the parent's change to be also
// applied to this frame, no matter what
// nsStyleContext::CalcStyleDifference says. CalcStyleDifference
// can't be trusted because it assumes any changes to the parent
// style context provider will be automatically propagated to
// the frame(s) with child style contexts.
ElementRestyler providerRestyler(PARENT_CONTEXT_FROM_CHILD_FRAME,
*this, providerFrame);
providerRestyler.Restyle(aRestyleHint);
assumeDifferenceHint = providerRestyler.HintsHandledForFrame();
// The provider's new context becomes the parent context of
// aSelf's context.
parentContext = providerFrame->StyleContext();
// Set |mResolvedChild| so we don't bother resolving the
// provider again.
mResolvedChild = providerFrame;
LOG_RESTYLE_CONTINUE("we had a provider frame");
// Continue restyling past the odd style context inheritance.
result = RestyleResult::eContinue;
canStopWithStyleChange = false;
}
LOG_RESTYLE("parentContext = %p", parentContext);
// do primary context
RefPtr<nsStyleContext> newContext;
nsIFrame* prevContinuation =
GetPrevContinuationWithPossiblySameStyle(aSelf);
nsStyleContext* prevContinuationContext;
bool copyFromContinuation =
prevContinuation &&
(prevContinuationContext = prevContinuation->StyleContext())
->GetPseudo() == oldContext->GetPseudo() &&
prevContinuationContext->GetParent() == parentContext;
if (copyFromContinuation) {
// Just use the style context from the frame's previous
// continuation.
LOG_RESTYLE("using previous continuation's context");
newContext = prevContinuationContext;
} else if (pseudoTag == nsCSSAnonBoxes::mozText) {
MOZ_ASSERT(aSelf->IsTextFrame());
newContext =
styleSet->ResolveStyleForText(aSelf->GetContent(), parentContext);
} else if (pseudoTag == nsCSSAnonBoxes::firstLetterContinuation) {
newContext = styleSet->ResolveStyleForFirstLetterContinuation(parentContext);
} else if (pseudoTag == nsCSSAnonBoxes::oofPlaceholder) {
// We still need to ResolveStyleForPlaceholder() here, because we may be
// doing a ruletree reconstruct and hence actually changing our style
// context.
newContext = styleSet->ResolveStyleForPlaceholder();
} else if (pseudoType == CSSPseudoElementType::NonInheritingAnonBox) {
// We still need to ResolveNonInheritingAnonymousBoxStyle() here, because we
// may be doing a ruletree reconstruct and hence actually changing our style
// context.
newContext = styleSet->ResolveNonInheritingAnonymousBoxStyle(pseudoTag);
}
else {
Element* element = ElementForStyleContext(mParentContent, aSelf, pseudoType);
if (!MustRestyleSelf(aRestyleHint, element)) {
if (CanReparentStyleContext(aRestyleHint)) {
LOG_RESTYLE("reparenting style context");
newContext =
styleSet->ReparentStyleContext(oldContext, parentContext, element);
} else {
// Use ResolveStyleWithReplacement either for actual replacements
// or, with no replacements, as a substitute for
// ReparentStyleContext that rebuilds the path in the rule tree
// rather than reusing the rule node, as we need to do during a
// rule tree reconstruct.
Element* pseudoElement = PseudoElementForStyleContext(aSelf, pseudoType);
MOZ_ASSERT(!element || element != pseudoElement,
"pseudo-element for selector matching should be "
"the anonymous content node that we create, "
"not the real element");
LOG_RESTYLE("resolving style with replacement");
nsRestyleHint rshint = aRestyleHint & ~eRestyle_SomeDescendants;
newContext =
styleSet->ResolveStyleWithReplacement(element, pseudoElement,
parentContext, oldContext,
rshint);
}
} else if (pseudoType == CSSPseudoElementType::InheritingAnonBox) {
newContext = styleSet->ResolveInheritingAnonymousBoxStyle(pseudoTag,
parentContext);
}
else {
if (pseudoTag) {
if (pseudoTag == nsCSSPseudoElements::before ||
pseudoTag == nsCSSPseudoElements::after) {
// XXX what other pseudos do we need to treat like this?
newContext = styleSet->ProbePseudoElementStyle(element,
pseudoType,
parentContext,
mTreeMatchContext);
if (!newContext) {
// This pseudo should no longer exist; gotta reframe
mHintsHandledBySelf |= nsChangeHint_ReconstructFrame;
mChangeList->AppendChange(aSelf, element,
nsChangeHint_ReconstructFrame);
// We're reframing anyway; just keep the same context
newContext = oldContext;
#ifdef DEBUG
// oldContext's parent might have had its style structs swapped out
// with parentContext, so to avoid any assertions that might
// otherwise trigger in oldContext's parent's destructor, we set a
// flag on oldContext to skip it and its descendants in
// nsStyleContext::AssertStructsNotUsedElsewhere.
if (oldContext->GetParent() != parentContext) {
oldContext->AddStyleBit(NS_STYLE_IS_GOING_AWAY);
}
#endif
}
} else {
// Don't expect XUL tree stuff here, since it needs a comparator and
// all.
NS_ASSERTION(pseudoType < CSSPseudoElementType::Count,
"Unexpected pseudo type");
Element* pseudoElement =
PseudoElementForStyleContext(aSelf, pseudoType);
MOZ_ASSERT(element != pseudoElement,
"pseudo-element for selector matching should be "
"the anonymous content node that we create, "
"not the real element");
newContext = styleSet->ResolvePseudoElementStyle(element,
pseudoType,
parentContext,
pseudoElement);
}
}
else {
NS_ASSERTION(aSelf->GetContent(),
"non pseudo-element frame without content node");
// Skip parent display based style fixup for anonymous subtrees:
TreeMatchContext::AutoParentDisplayBasedStyleFixupSkipper
parentDisplayBasedFixupSkipper(mTreeMatchContext,
element->IsRootOfNativeAnonymousSubtree());
newContext = styleSet->ResolveStyleFor(element, parentContext,
mTreeMatchContext);
}
}
}
MOZ_ASSERT(newContext);
if (!parentContext) {
if (oldContext->RuleNode() == newContext->RuleNode() &&
oldContext->IsLinkContext() == newContext->IsLinkContext() &&
oldContext->RelevantLinkVisited() ==
newContext->RelevantLinkVisited()) {
// We're the root of the style context tree and the new style
// context returned has the same rule node. This means that
// we can use FindChildWithRules to keep a lot of the old
// style contexts around. However, we need to start from the
// same root.
LOG_RESTYLE("restyling root and keeping old context");
LOG_RESTYLE_IF(this, result != RestyleResult::eContinue,
"continuing restyle since this is the root");
newContext = oldContext;
// Never consider stopping restyling at the root.
result = RestyleResult::eContinue;
canStopWithStyleChange = false;
}
}
LOG_RESTYLE("oldContext = %p, newContext = %p%s",
oldContext.get(), newContext.get(),
oldContext == newContext ? (const char*) " (same)" :
(const char*) "");
if (newContext != oldContext) {
if (oldContext->IsShared()) {
// If the old style context was shared, then we can't return
// RestyleResult::eStop and patch its parent to point to the
// new parent style context, as that change might not be valid
// for the other frames sharing the style context.
LOG_RESTYLE_CONTINUE("the old style context is shared");
result = RestyleResult::eContinue;
// It is not safe to return RestyleResult::eStopWithStyleChange
// when oldContext is shared and newContext has different
// inherited style data, regardless of whether the oldContext has
// that inherited style data cached. We can't simply rely on the
// samePointerStructs check later on, as the descendent style
// contexts just might not have had their inherited style data
// requested yet (which is possible for example if we flush style
// between resolving an initial style context for a frame and
// building its display list items). Therefore we must compare
// the rule nodes of oldContext and newContext to see if the
// restyle results in new inherited style data. If not, then
// we can continue assuming that RestyleResult::eStopWithStyleChange
// is safe. Without this check, we could end up with style contexts
// shared between elements which should have different styles.
if (!CommonInheritedStyleData(oldContext->RuleNode(),
newContext->RuleNode())) {
canStopWithStyleChange = false;
}
}
// Look at some details of the new style context to see if it would
// be safe to stop restyling, if we discover it has the same style
// data as the old style context.
ComputeRestyleResultFromNewContext(aSelf, newContext,
result, canStopWithStyleChange);
uint32_t equalStructs = 0;
uint32_t samePointerStructs = 0;
if (copyFromContinuation) {
// In theory we should know whether there was any style data difference,
// since we would have calculated that in the previous call to
// RestyleSelf, so until we perform only one restyling per chain-of-
// same-style continuations (bug 918064), we need to check again here to
// determine whether it is safe to stop restyling.
if (result == RestyleResult::eStop) {
oldContext->CalcStyleDifference(newContext,
&equalStructs,
&samePointerStructs);
if (equalStructs != NS_STYLE_INHERIT_MASK) {
// At least one struct had different data in it, so we must
// continue restyling children.
LOG_RESTYLE_CONTINUE("there is different style data: %s",
GeckoRestyleManager::StructNamesToString(
~equalStructs & NS_STYLE_INHERIT_MASK).get());
result = RestyleResult::eContinue;
}
}
} else {
bool changedStyle =
GeckoRestyleManager::TryInitiatingTransition(mPresContext,
aSelf->GetContent(),
oldContext, &newContext);
if (changedStyle) {
LOG_RESTYLE_CONTINUE("TryInitiatingTransition changed the new style "
"context");
result = RestyleResult::eContinue;
canStopWithStyleChange = false;
}
CaptureChange(oldContext, newContext, assumeDifferenceHint,
&equalStructs, &samePointerStructs);
if (equalStructs != NS_STYLE_INHERIT_MASK) {
// At least one struct had different data in it, so we must
// continue restyling children.
LOG_RESTYLE_CONTINUE("there is different style data: %s",
GeckoRestyleManager::StructNamesToString(
~equalStructs & NS_STYLE_INHERIT_MASK).get());
result = RestyleResult::eContinue;
}
}
if (canStopWithStyleChange) {
// If any inherited struct pointers are different, or if any
// reset struct pointers are different and we have descendants
// that rely on those reset struct pointers, we can't return
// RestyleResult::eStopWithStyleChange.
if ((samePointerStructs & NS_STYLE_INHERITED_STRUCT_MASK) !=
NS_STYLE_INHERITED_STRUCT_MASK) {
LOG_RESTYLE("can't return RestyleResult::eStopWithStyleChange since "
"there is different inherited data");
canStopWithStyleChange = false;
} else if ((samePointerStructs & NS_STYLE_RESET_STRUCT_MASK) !=
NS_STYLE_RESET_STRUCT_MASK &&
oldContext->HasChildThatUsesResetStyle()) {
LOG_RESTYLE("can't return RestyleResult::eStopWithStyleChange since "
"there is different reset data and descendants use it");
canStopWithStyleChange = false;
}
}
if (result == RestyleResult::eStop) {
// Since we currently have RestyleResult::eStop, we know at this
// point that all of our style structs are equal in terms of styles.
// However, some of them might be different pointers. Since our
// descendants might share those pointers, we have to continue to
// restyling our descendants.
//
// However, because of the swapping of equal structs we've done on
// ancestors (later in this function), we've ensured that for structs
// that cannot be stored in the rule tree, we keep the old equal structs
// around rather than replacing them with new ones. This means that we
// only time we hit this deoptimization is either
//
// (a) when at least one of the (old or new) equal structs could be stored
// in the rule tree, and those structs are then inherited (by pointer
// sharing) to descendant style contexts; or
//
// (b) when we were unable to swap the structs on the parent because
// either or both of the old parent and new parent are shared.
//
// FIXME This loop could be rewritten as bit operations on
// oldContext->mBits and samePointerStructs.
for (nsStyleStructID sid = nsStyleStructID(0);
sid < nsStyleStructID_Length;
sid = nsStyleStructID(sid + 1)) {
if (oldContext->HasCachedDependentStyleData(sid) &&
!(samePointerStructs & nsCachedStyleData::GetBitForSID(sid))) {
LOG_RESTYLE_CONTINUE("there are different struct pointers");
result = RestyleResult::eContinue;
break;
}
}
}
// From this point we no longer do any assignments of
// RestyleResult::eContinue to |result|. If canStopWithStyleChange is true,
// it means that we can convert |result| (whether it is
// RestyleResult::eContinue or RestyleResult::eStop) into
// RestyleResult::eStopWithStyleChange.
if (canStopWithStyleChange) {
LOG_RESTYLE("converting %s into RestyleResult::eStopWithStyleChange",
RestyleResultToString(result).get());
result = RestyleResult::eStopWithStyleChange;
}
if (aRestyleHint & eRestyle_ForceDescendants) {
result = RestyleResult::eContinueAndForceDescendants;
}
if (!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame)) {
// If the frame gets regenerated, let it keep its old context,
// which is important to maintain various invariants about
// frame types matching their style contexts.
// Note that this check even makes sense if we didn't call
// CaptureChange because of copyFromContinuation being true,
// since we'll have copied the existing context from the
// previous continuation, so newContext == oldContext.
if (result != RestyleResult::eStop) {
if (copyFromContinuation) {
LOG_RESTYLE("not swapping style structs, since we copied from a "
"continuation");
} else if (oldContext->IsShared() && newContext->IsShared()) {
LOG_RESTYLE("not swapping style structs, since both old and contexts "
"are shared");
} else if (oldContext->IsShared()) {
LOG_RESTYLE("not swapping style structs, since the old context is "
"shared");
} else if (newContext->IsShared()) {
LOG_RESTYLE("not swapping style structs, since the new context is "
"shared");
} else {
if (result == RestyleResult::eStopWithStyleChange) {
LOG_RESTYLE("recording a style struct swap between %p and %p to "
"do if RestyleResult::eStopWithStyleChange fails",
oldContext.get(), newContext.get());
SwapInstruction* swap = aSwaps.AppendElement();
swap->mOldContext = oldContext;
swap->mNewContext = newContext;
swap->mStructsToSwap = equalStructs;
} else {
LOG_RESTYLE("swapping style structs between %p and %p",
oldContext.get(), newContext.get());
oldContext->SwapStyleData(newContext, equalStructs);
*aSwappedStructs |= equalStructs;
}
#ifdef RESTYLE_LOGGING
uint32_t structs = GeckoRestyleManager::StructsToLog() & equalStructs;
if (structs) {
LOG_RESTYLE_INDENT();
LOG_RESTYLE("old style context now has: %s",
oldContext->GetCachedStyleDataAsString(structs).get());
LOG_RESTYLE("new style context now has: %s",
newContext->GetCachedStyleDataAsString(structs).get());
}
#endif
}
LOG_RESTYLE("setting new style context");
aSelf->SetStyleContext(newContext);
}
} else {
LOG_RESTYLE("not setting new style context, since we'll reframe");
// We need to keep the new parent alive, in case it had structs
// swapped into it that our frame's style context still has cached.
// This is a similar scenario to the one described in the
// ElementRestyler::Restyle comment where we append to
// mSwappedStructOwners.
//
// We really only need to do this if we did swap structs on the
// parent, but we don't have that information here.
mSwappedStructOwners.AppendElement(newContext->GetParent());
}
} else {
if (aRestyleHint & eRestyle_ForceDescendants) {
result = RestyleResult::eContinueAndForceDescendants;
}
}
oldContext = nullptr;
// do additional contexts
// XXXbz might be able to avoid selector matching here in some
// cases; won't worry about it for now.
int32_t contextIndex = 0;
for (nsStyleContext* oldExtraContext;
(oldExtraContext = aSelf->GetAdditionalStyleContext(contextIndex));
++contextIndex) {
LOG_RESTYLE("extra context %d", contextIndex);
LOG_RESTYLE_INDENT();
RefPtr<nsStyleContext> newExtraContext;
nsIAtom* const extraPseudoTag = oldExtraContext->GetPseudo();
const CSSPseudoElementType extraPseudoType =
oldExtraContext->GetPseudoType();
NS_ASSERTION(extraPseudoTag &&
!nsCSSAnonBoxes::IsNonElement(extraPseudoTag),
"extra style context is not pseudo element");
Element* element =
(extraPseudoType != CSSPseudoElementType::InheritingAnonBox &&
extraPseudoType != CSSPseudoElementType::NonInheritingAnonBox)
? mContent->AsElement() : nullptr;
if (extraPseudoType == CSSPseudoElementType::NonInheritingAnonBox) {
newExtraContext =
styleSet->ResolveNonInheritingAnonymousBoxStyle(extraPseudoTag);
} else if (!MustRestyleSelf(aRestyleHint, element)) {
if (CanReparentStyleContext(aRestyleHint)) {
newExtraContext =
styleSet->ReparentStyleContext(oldExtraContext, newContext, element);
} else {
// Use ResolveStyleWithReplacement as a substitute for
// ReparentStyleContext that rebuilds the path in the rule tree
// rather than reusing the rule node, as we need to do during a
// rule tree reconstruct.
Element* pseudoElement =
PseudoElementForStyleContext(aSelf, extraPseudoType);
MOZ_ASSERT(!element || element != pseudoElement,
"pseudo-element for selector matching should be "
"the anonymous content node that we create, "
"not the real element");
newExtraContext =
styleSet->ResolveStyleWithReplacement(element, pseudoElement,
newContext, oldExtraContext,
nsRestyleHint(0));
}
} else if (extraPseudoType == CSSPseudoElementType::InheritingAnonBox) {
newExtraContext = styleSet->
ResolveInheritingAnonymousBoxStyle(extraPseudoTag, newContext);
} else {
// Don't expect XUL tree stuff here, since it needs a comparator and
// all.
NS_ASSERTION(extraPseudoType < CSSPseudoElementType::Count,
"Unexpected type");
newExtraContext = styleSet->ResolvePseudoElementStyle(mContent->AsElement(),
extraPseudoType,
newContext,
nullptr);
}
MOZ_ASSERT(newExtraContext);
LOG_RESTYLE("newExtraContext = %p", newExtraContext.get());
if (oldExtraContext != newExtraContext) {
uint32_t equalStructs;
uint32_t samePointerStructs;
CaptureChange(oldExtraContext, newExtraContext, assumeDifferenceHint,
&equalStructs, &samePointerStructs);
if (!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame)) {
LOG_RESTYLE("setting new extra style context");
aSelf->SetAdditionalStyleContext(contextIndex, newExtraContext);
} else {
LOG_RESTYLE("not setting new extra style context, since we'll reframe");
}
}
}
LOG_RESTYLE("returning %s", RestyleResultToString(result).get());
return result;
}
void
ElementRestyler::RestyleChildren(nsRestyleHint aChildRestyleHint)
{
MOZ_ASSERT(!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame),
"No need to do this if we're planning to reframe already.");
// We'd like style resolution to be exact in the sense that an
// animation-only style flush flushes only the styles it requests
// flushing and doesn't update any other styles. This means avoiding
// constructing new frames during such a flush.
//
// For a ::before or ::after, we'll do an eRestyle_Subtree due to
// RestyleHintForOp in nsCSSRuleProcessor.cpp (via its
// HasAttributeDependentStyle or HasStateDependentStyle), given that
// we store pseudo-elements in selectors like they were children.
//
// Also, it's faster to skip the work we do on undisplayed children
// and pseudo-elements when we can skip it.
bool mightReframePseudos = aChildRestyleHint & eRestyle_Subtree;
RestyleUndisplayedDescendants(aChildRestyleHint);
// Check whether we might need to create a new ::before frame.
// There's no need to do this if we're planning to reframe already
// or if we're not forcing restyles on kids.
// It's also important to check mHintsHandledBySelf since we use
// mFrame->StyleContext(), which is out of date if mHintsHandledBySelf
// has a ReconstructFrame hint. Using an out of date style context could
// trigger assertions about mismatched rule trees.
if (!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame) &&
mightReframePseudos) {
MaybeReframeForBeforePseudo();
}
// There is no need to waste time crawling into a frame's children
// on a frame change. The act of reconstructing frames will force
// new style contexts to be resolved on all of this frame's
// descendants anyway, so we want to avoid wasting time processing
// style contexts that we're just going to throw away anyway. - dwh
// It's also important to check mHintsHandledBySelf since reresolving the
// kids would use mFrame->StyleContext(), which is out of date if
// mHintsHandledBySelf has a ReconstructFrame hint; doing this could
// trigger assertions about mismatched rule trees.
nsIFrame* lastContinuation;
if (!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame)) {
InitializeAccessibilityNotifications(mFrame->StyleContext());
for (nsIFrame* f = mFrame; f;
f = GeckoRestyleManager::GetNextContinuationWithSameStyle(f, f->StyleContext())) {
lastContinuation = f;
RestyleContentChildren(f, aChildRestyleHint);
}
SendAccessibilityNotifications();
}
// Check whether we might need to create a new ::after frame.
// See comments above regarding :before.
if (!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame) &&
mightReframePseudos) {
MaybeReframeForAfterPseudo(lastContinuation);
}
}
void
ElementRestyler::RestyleChildrenOfDisplayContentsElement(
nsIFrame* aParentFrame,
nsStyleContext* aNewContext,
nsChangeHint aMinHint,
RestyleTracker& aRestyleTracker,
nsRestyleHint aRestyleHint,
const RestyleHintData& aRestyleHintData)
{
MOZ_ASSERT(!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame),
"why call me?");
const bool mightReframePseudos = aRestyleHint & eRestyle_Subtree;
DoRestyleUndisplayedDescendants(nsRestyleHint(0), mContent, aNewContext);
if (!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame) &&
mightReframePseudos) {
MaybeReframeForPseudo(CSSPseudoElementType::before,
aParentFrame, nullptr, mContent, aNewContext);
}
if (!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame) &&
mightReframePseudos) {
MaybeReframeForPseudo(CSSPseudoElementType::after,
aParentFrame, nullptr, mContent, aNewContext);
}
if (!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame)) {
InitializeAccessibilityNotifications(aNewContext);
// Then process child frames for content that is a descendant of mContent.
// XXX perhaps it's better to walk child frames (before reresolving
// XXX undisplayed contexts above) and mark those that has a stylecontext
// XXX leading up to mContent's old context? (instead of the
// XXX ContentIsDescendantOf check below)
nsIFrame::ChildListIterator lists(aParentFrame);
for ( ; !lists.IsDone(); lists.Next()) {
for (nsIFrame* f : lists.CurrentList()) {
if (nsContentUtils::ContentIsDescendantOf(f->GetContent(), mContent) &&
!f->GetPrevContinuation()) {
if (!(f->GetStateBits() & NS_FRAME_OUT_OF_FLOW)) {
ComputeStyleChangeFor(f, mChangeList, aMinHint, aRestyleTracker,
aRestyleHint, aRestyleHintData,
mContextsToClear, mSwappedStructOwners);
}
}
}
}
}
if (!(mHintsHandledBySelf & nsChangeHint_ReconstructFrame)) {
SendAccessibilityNotifications();
}
}
void
ElementRestyler::ComputeStyleChangeFor(nsIFrame* aFrame,
nsStyleChangeList* aChangeList,
nsChangeHint aMinChange,
RestyleTracker& aRestyleTracker,
nsRestyleHint aRestyleHint,
const RestyleHintData& aRestyleHintData,
nsTArray<ContextToClear>&
aContextsToClear,
nsTArray<RefPtr<nsStyleContext>>&
aSwappedStructOwners)
{
PROFILER_LABEL("ElementRestyler", "ComputeStyleChangeFor",
js::ProfileEntry::Category::CSS);
nsIContent* content = aFrame->GetContent();
if (aMinChange) {
aChangeList->AppendChange(aFrame, content, aMinChange);
}
NS_ASSERTION(!aFrame->GetPrevContinuation(),
"must start with the first continuation");
// We want to start with this frame and walk all its next-in-flows,
// as well as all its ib-split siblings and their next-in-flows,
// reresolving style on all the frames we encounter in this walk that
// we didn't reach already. In the normal case, this will mean only
// restyling the first two block-in-inline splits and no
// continuations, and skipping everything else. However, when we have
// a style change targeted at an element inside a context where styles
// vary between continuations (e.g., a style change on an element that
// extends from inside a styled ::first-line to outside of that first
// line), we might restyle more than that.
nsPresContext* presContext = aFrame->PresContext();
TreeMatchContext treeMatchContext(true,
nsRuleWalker::eRelevantLinkUnvisited,
presContext->Document());
Element* parent =
content ? content->GetParentElementCrossingShadowRoot() : nullptr;
treeMatchContext.InitAncestors(parent);
nsTArray<nsCSSSelector*> selectorsForDescendants;
selectorsForDescendants.AppendElements(
aRestyleHintData.mSelectorsForDescendants);
nsTArray<nsIContent*> visibleKidsOfHiddenElement;
nsIFrame* nextIBSibling;
for (nsIFrame* ibSibling = aFrame; ibSibling; ibSibling = nextIBSibling) {
nextIBSibling =
GeckoRestyleManager::GetNextBlockInInlineSibling(ibSibling);
if (nextIBSibling) {
// Don't allow some ib-split siblings to be processed with
// RestyleResult::eStopWithStyleChange and others not.
aRestyleHint |= eRestyle_Force;
}
// Outer loop over ib-split siblings
for (nsIFrame* cont = ibSibling; cont; cont = cont->GetNextContinuation()) {
if (GetPrevContinuationWithSameStyle(cont)) {
// We already handled this element when dealing with its earlier
// continuation.
continue;
}
// Inner loop over next-in-flows of the current frame
ElementRestyler restyler(presContext, cont, aChangeList,
aMinChange, aRestyleTracker,
selectorsForDescendants,
treeMatchContext,
visibleKidsOfHiddenElement,
aContextsToClear, aSwappedStructOwners);
restyler.Restyle(aRestyleHint);
if (restyler.HintsHandledForFrame() & nsChangeHint_ReconstructFrame) {
// If it's going to cause a framechange, then don't bother
// with the continuations or ib-split siblings since they'll be
// clobbered by the frame reconstruct anyway.
NS_ASSERTION(!cont->GetPrevContinuation(),
"continuing frame had more severe impact than first-in-flow");
return;
}
}
}
}
// The structure of this method parallels ConditionallyRestyleUndisplayedDescendants.
// If you update this method, you probably want to update that one too.
void
ElementRestyler::RestyleUndisplayedDescendants(nsRestyleHint aChildRestyleHint)
{
nsIContent* undisplayedParent;
if (MustCheckUndisplayedContent(mFrame, undisplayedParent)) {
DoRestyleUndisplayedDescendants(aChildRestyleHint, undisplayedParent,
mFrame->StyleContext());
}
}
// The structure of this method parallels DoConditionallyRestyleUndisplayedDescendants.
// If you update this method, you probably want to update that one too.
void
ElementRestyler::DoRestyleUndisplayedDescendants(nsRestyleHint aChildRestyleHint,
nsIContent* aParent,
nsStyleContext* aParentContext)
{
nsCSSFrameConstructor* fc = mPresContext->FrameConstructor();
UndisplayedNode* nodes = fc->GetAllUndisplayedContentIn(aParent);
RestyleUndisplayedNodes(aChildRestyleHint, nodes, aParent,
aParentContext, StyleDisplay::None);
nodes = fc->GetAllDisplayContentsIn(aParent);
RestyleUndisplayedNodes(aChildRestyleHint, nodes, aParent,
aParentContext, StyleDisplay::Contents);
}
// The structure of this method parallels ConditionallyRestyleUndisplayedNodes.
// If you update this method, you probably want to update that one too.
void
ElementRestyler::RestyleUndisplayedNodes(nsRestyleHint aChildRestyleHint,
UndisplayedNode* aUndisplayed,
nsIContent* aUndisplayedParent,
nsStyleContext* aParentContext,
const StyleDisplay aDisplay)
{
nsIContent* undisplayedParent = aUndisplayedParent;
UndisplayedNode* undisplayed = aUndisplayed;
TreeMatchContext::AutoAncestorPusher pusher(&mTreeMatchContext);
if (undisplayed) {
pusher.PushAncestorAndStyleScope(undisplayedParent);
}
for (; undisplayed; undisplayed = undisplayed->getNext()) {
NS_ASSERTION(undisplayedParent ||
undisplayed->mContent ==
mPresContext->Document()->GetRootElement(),
"undisplayed node child of null must be root");
NS_ASSERTION(!undisplayed->mStyle->GetPseudo(),
"Shouldn't have random pseudo style contexts in the "
"undisplayed map");
LOG_RESTYLE("RestyleUndisplayedChildren: undisplayed->mContent = %p",
undisplayed->mContent.get());
// Get the parent of the undisplayed content and check if it is a XBL
// children element. Push the children element as an ancestor here because it does
// not have a frame and would not otherwise be pushed as an ancestor.
nsIContent* parent = undisplayed->mContent->GetParent();
TreeMatchContext::AutoAncestorPusher insertionPointPusher(&mTreeMatchContext);
if (parent && nsContentUtils::IsContentInsertionPoint(parent)) {
insertionPointPusher.PushAncestorAndStyleScope(parent);
}
nsRestyleHint thisChildHint = aChildRestyleHint;
nsAutoPtr<RestyleTracker::RestyleData> undisplayedRestyleData;
Element* element = undisplayed->mContent->AsElement();
if (mRestyleTracker.GetRestyleData(element,
undisplayedRestyleData)) {
thisChildHint =
nsRestyleHint(thisChildHint | undisplayedRestyleData->mRestyleHint);
}
RefPtr<nsStyleContext> undisplayedContext;
nsStyleSet* styleSet = StyleSet();
if (MustRestyleSelf(thisChildHint, element)) {
undisplayedContext =
styleSet->ResolveStyleFor(element, aParentContext, mTreeMatchContext);
} else if (CanReparentStyleContext(thisChildHint)) {
undisplayedContext =
styleSet->ReparentStyleContext(undisplayed->mStyle,
aParentContext,
element);
} else {
// Use ResolveStyleWithReplacement either for actual
// replacements, or as a substitute for ReparentStyleContext
// that rebuilds the path in the rule tree rather than reusing
// the rule node, as we need to do during a rule tree
// reconstruct.
nsRestyleHint rshint = thisChildHint & ~eRestyle_SomeDescendants;
undisplayedContext =
styleSet->ResolveStyleWithReplacement(element, nullptr,
aParentContext,
undisplayed->mStyle,
rshint);
}
const nsStyleDisplay* display = undisplayedContext->StyleDisplay();
if (display->mDisplay != aDisplay) {
NS_ASSERTION(element, "Must have undisplayed content");
mChangeList->AppendChange(nullptr, element,
nsChangeHint_ReconstructFrame);
// The node should be removed from the undisplayed map when
// we reframe it.
} else {
// update the undisplayed node with the new context
undisplayed->mStyle = undisplayedContext;
if (aDisplay == StyleDisplay::Contents) {
DoRestyleUndisplayedDescendants(aChildRestyleHint, element,
undisplayed->mStyle);
}
}
}
}
void
ElementRestyler::MaybeReframeForBeforePseudo()
{
MaybeReframeForPseudo(CSSPseudoElementType::before,
mFrame, mFrame, mFrame->GetContent(),
mFrame->StyleContext());
}
/**
* aFrame is the last continuation or block-in-inline sibling that this
* ElementRestyler is restyling.
*/
void
ElementRestyler::MaybeReframeForAfterPseudo(nsIFrame* aFrame)
{
MOZ_ASSERT(aFrame);
MaybeReframeForPseudo(CSSPseudoElementType::after,
aFrame, aFrame, aFrame->GetContent(),
aFrame->StyleContext());
}
#ifdef DEBUG
bool
ElementRestyler::MustReframeForBeforePseudo()
{
return MustReframeForPseudo(CSSPseudoElementType::before,
mFrame, mFrame, mFrame->GetContent(),
mFrame->StyleContext());
}
bool
ElementRestyler::MustReframeForAfterPseudo(nsIFrame* aFrame)
{
MOZ_ASSERT(aFrame);
return MustReframeForPseudo(CSSPseudoElementType::after,
aFrame, aFrame, aFrame->GetContent(),
aFrame->StyleContext());
}
#endif
void
ElementRestyler::MaybeReframeForPseudo(CSSPseudoElementType aPseudoType,
nsIFrame* aGenConParentFrame,
nsIFrame* aFrame,
nsIContent* aContent,
nsStyleContext* aStyleContext)
{
if (MustReframeForPseudo(aPseudoType, aGenConParentFrame, aFrame, aContent,
aStyleContext)) {
// Have to create the new ::before/::after frame.
LOG_RESTYLE("MaybeReframeForPseudo, appending "
"nsChangeHint_ReconstructFrame");
mHintsHandledBySelf |= nsChangeHint_ReconstructFrame;
mChangeList->AppendChange(aFrame, aContent, nsChangeHint_ReconstructFrame);
}
}
bool
ElementRestyler::MustReframeForPseudo(CSSPseudoElementType aPseudoType,
nsIFrame* aGenConParentFrame,
nsIFrame* aFrame,
nsIContent* aContent,
nsStyleContext* aStyleContext)
{
MOZ_ASSERT(aPseudoType == CSSPseudoElementType::before ||
aPseudoType == CSSPseudoElementType::after);
// Make sure not to do this for pseudo-frames...
if (aStyleContext->GetPseudo()) {
return false;
}
// ... or frames that can't have generated content.
if (!(aGenConParentFrame->GetStateBits() & NS_FRAME_MAY_HAVE_GENERATED_CONTENT)) {
// Our content insertion frame might have gotten flagged.
nsContainerFrame* cif = aGenConParentFrame->GetContentInsertionFrame();
if (!cif || !(cif->GetStateBits() & NS_FRAME_MAY_HAVE_GENERATED_CONTENT)) {
return false;
}
}
if (aPseudoType == CSSPseudoElementType::before) {
// Check for a ::before pseudo style and the absence of a ::before content,
// but only if aFrame is null or is the first continuation/ib-split.
if ((aFrame && !nsLayoutUtils::IsFirstContinuationOrIBSplitSibling(aFrame)) ||
nsLayoutUtils::GetBeforeFrame(aContent)) {
return false;
}
} else {
// Similarly for ::after, but check for being the last continuation/
// ib-split.
if ((aFrame && nsLayoutUtils::GetNextContinuationOrIBSplitSibling(aFrame)) ||
nsLayoutUtils::GetAfterFrame(aContent)) {
return false;
}
}
// Checking for a ::before frame (which we do above) is cheaper than getting
// the ::before style context here.
return nsLayoutUtils::HasPseudoStyle(aContent, aStyleContext, aPseudoType,
mPresContext);
}
void
ElementRestyler::InitializeAccessibilityNotifications(nsStyleContext* aNewContext)
{
#ifdef ACCESSIBILITY
// Notify a11y for primary frame only if it's a root frame of visibility
// changes or its parent frame was hidden while it stays visible and
// it is not inside a {ib} split or is the first frame of {ib} split.
if (nsIPresShell::IsAccessibilityActive() &&
(!mFrame ||
(!mFrame->GetPrevContinuation() &&
!mFrame->FrameIsNonFirstInIBSplit()))) {
if (mDesiredA11yNotifications == eSendAllNotifications) {
bool isFrameVisible = aNewContext->StyleVisibility()->IsVisible();
if (isFrameVisible != mWasFrameVisible) {
if (isFrameVisible) {
// Notify a11y the element (perhaps with its children) was shown.
// We don't fall into this case if this element gets or stays shown
// while its parent becomes hidden.
mKidsDesiredA11yNotifications = eSkipNotifications;
mOurA11yNotification = eNotifyShown;
} else {
// The element is being hidden; its children may stay visible, or
// become visible after being hidden previously. If we'll find
// visible children then we should notify a11y about that as if
// they were inserted into tree. Notify a11y this element was
// hidden.
mKidsDesiredA11yNotifications = eNotifyIfShown;
mOurA11yNotification = eNotifyHidden;
}
}
} else if (mDesiredA11yNotifications == eNotifyIfShown &&
aNewContext->StyleVisibility()->IsVisible()) {
// Notify a11y that element stayed visible while its parent was hidden.
nsIContent* c = mFrame ? mFrame->GetContent() : mContent;
mVisibleKidsOfHiddenElement.AppendElement(c);
mKidsDesiredA11yNotifications = eSkipNotifications;
}
}
#endif
}
// The structure of this method parallels ConditionallyRestyleContentChildren.
// If you update this method, you probably want to update that one too.
void
ElementRestyler::RestyleContentChildren(nsIFrame* aParent,
nsRestyleHint aChildRestyleHint)
{
LOG_RESTYLE("RestyleContentChildren");
nsIFrame::ChildListIterator lists(aParent);
TreeMatchContext::AutoAncestorPusher ancestorPusher(&mTreeMatchContext);
if (!lists.IsDone()) {
ancestorPusher.PushAncestorAndStyleScope(mContent);
}
for (; !lists.IsDone(); lists.Next()) {
for (nsIFrame* child : lists.CurrentList()) {
// Out-of-flows are reached through their placeholders. Continuations
// and block-in-inline splits are reached through those chains.
if (!(child->GetStateBits() & NS_FRAME_OUT_OF_FLOW) &&
!GetPrevContinuationWithSameStyle(child)) {
// Get the parent of the child frame's content and check if it
// is a XBL children element. Push the children element as an
// ancestor here because it does not have a frame and would not
// otherwise be pushed as an ancestor.
// Check if the frame has a content because |child| may be a
// nsPageFrame that does not have a content.
nsIContent* parent = child->GetContent() ? child->GetContent()->GetParent() : nullptr;
TreeMatchContext::AutoAncestorPusher insertionPointPusher(&mTreeMatchContext);
if (parent && nsContentUtils::IsContentInsertionPoint(parent)) {
insertionPointPusher.PushAncestorAndStyleScope(parent);
}
// only do frames that are in flow
if (child->IsPlaceholderFrame()) { // placeholder
// get out of flow frame and recur there
nsIFrame* outOfFlowFrame =
nsPlaceholderFrame::GetRealFrameForPlaceholder(child);
NS_ASSERTION(outOfFlowFrame, "no out-of-flow frame");
NS_ASSERTION(outOfFlowFrame != mResolvedChild,
"out-of-flow frame not a true descendant");
// |nsFrame::GetParentStyleContext| checks being out
// of flow so that this works correctly.
do {
if (GetPrevContinuationWithSameStyle(outOfFlowFrame)) {
// Later continuations are likely restyled as a result of
// the restyling of the previous continuation.
// (Currently that's always true, but it's likely to
// change if we implement overflow:fragments or similar.)
continue;
}
ElementRestyler oofRestyler(*this, outOfFlowFrame,
FOR_OUT_OF_FLOW_CHILD);
oofRestyler.Restyle(aChildRestyleHint);
} while ((outOfFlowFrame = outOfFlowFrame->GetNextContinuation()));
// reresolve placeholder's context under the same parent
// as the out-of-flow frame
ElementRestyler phRestyler(*this, child, 0);
phRestyler.Restyle(aChildRestyleHint);
}
else { // regular child frame
if (child != mResolvedChild) {
ElementRestyler childRestyler(*this, child, 0);
childRestyler.Restyle(aChildRestyleHint);
}
}
}
}
}
// XXX need to do overflow frames???
}
void
ElementRestyler::SendAccessibilityNotifications()
{
#ifdef ACCESSIBILITY
// Send notifications about visibility changes.
if (mOurA11yNotification == eNotifyShown) {
nsAccessibilityService* accService = nsIPresShell::AccService();
if (accService) {
nsIPresShell* presShell = mPresContext->GetPresShell();
nsIContent* content = mFrame ? mFrame->GetContent() : mContent;
accService->ContentRangeInserted(presShell, content->GetParent(),
content,
content->GetNextSibling());
}
} else if (mOurA11yNotification == eNotifyHidden) {
nsAccessibilityService* accService = nsIPresShell::AccService();
if (accService) {
nsIPresShell* presShell = mPresContext->GetPresShell();
nsIContent* content = mFrame ? mFrame->GetContent() : mContent;
accService->ContentRemoved(presShell, content);
// Process children staying shown.
uint32_t visibleContentCount = mVisibleKidsOfHiddenElement.Length();
for (uint32_t idx = 0; idx < visibleContentCount; idx++) {
nsIContent* childContent = mVisibleKidsOfHiddenElement[idx];
accService->ContentRangeInserted(presShell, childContent->GetParent(),
childContent,
childContent->GetNextSibling());
}
mVisibleKidsOfHiddenElement.Clear();
}
}
#endif
}
static void
ClearCachedInheritedStyleDataOnDescendants(
nsTArray<ElementRestyler::ContextToClear>& aContextsToClear)
{
for (size_t i = 0; i < aContextsToClear.Length(); i++) {
auto& entry = aContextsToClear[i];
if (!entry.mStyleContext->HasSingleReference()) {
entry.mStyleContext->ClearCachedInheritedStyleDataOnDescendants(
entry.mStructs);
}
entry.mStyleContext = nullptr;
}
}
void
GeckoRestyleManager::ComputeAndProcessStyleChange(
nsIFrame* aFrame,
nsChangeHint aMinChange,
RestyleTracker& aRestyleTracker,
nsRestyleHint aRestyleHint,
const RestyleHintData& aRestyleHintData)
{
MOZ_ASSERT(mReframingStyleContexts, "should have rsc");
nsStyleChangeList changeList(StyleBackendType::Gecko);
nsTArray<ElementRestyler::ContextToClear> contextsToClear;
// swappedStructOwners needs to be kept alive until after
// ProcessRestyledFrames and ClearCachedInheritedStyleDataOnDescendants
// calls; see comment in ElementRestyler::Restyle.
nsTArray<RefPtr<nsStyleContext>> swappedStructOwners;
ElementRestyler::ComputeStyleChangeFor(aFrame, &changeList, aMinChange,
aRestyleTracker, aRestyleHint,
aRestyleHintData,
contextsToClear, swappedStructOwners);
ProcessRestyledFrames(changeList);
ClearCachedInheritedStyleDataOnDescendants(contextsToClear);
}
void
GeckoRestyleManager::ComputeAndProcessStyleChange(
nsStyleContext* aNewContext,
Element* aElement,
nsChangeHint aMinChange,
RestyleTracker& aRestyleTracker,
nsRestyleHint aRestyleHint,
const RestyleHintData& aRestyleHintData)
{
MOZ_ASSERT(mReframingStyleContexts, "should have rsc");
MOZ_ASSERT(aNewContext->StyleDisplay()->mDisplay == StyleDisplay::Contents);
nsIFrame* frame = GetNearestAncestorFrame(aElement);
MOZ_ASSERT(frame, "display:contents node in map although it's a "
"display:none descendant?");
TreeMatchContext treeMatchContext(true,
nsRuleWalker::eRelevantLinkUnvisited,
frame->PresContext()->Document());
nsIContent* parent = aElement->GetParent();
Element* parentElement =
parent && parent->IsElement() ? parent->AsElement() : nullptr;
treeMatchContext.InitAncestors(parentElement);
nsTArray<nsCSSSelector*> selectorsForDescendants;
nsTArray<nsIContent*> visibleKidsOfHiddenElement;
nsTArray<ElementRestyler::ContextToClear> contextsToClear;
// swappedStructOwners needs to be kept alive until after
// ProcessRestyledFrames and ClearCachedInheritedStyleDataOnDescendants
// calls; see comment in ElementRestyler::Restyle.
nsTArray<RefPtr<nsStyleContext>> swappedStructOwners;
nsStyleChangeList changeList(StyleBackendType::Gecko);
ElementRestyler r(frame->PresContext(), aElement, &changeList, aMinChange,
aRestyleTracker, selectorsForDescendants, treeMatchContext,
visibleKidsOfHiddenElement, contextsToClear,
swappedStructOwners);
r.RestyleChildrenOfDisplayContentsElement(frame, aNewContext, aMinChange,
aRestyleTracker,
aRestyleHint, aRestyleHintData);
ProcessRestyledFrames(changeList);
ClearCachedInheritedStyleDataOnDescendants(contextsToClear);
}
nsStyleSet*
ElementRestyler::StyleSet() const
{
MOZ_ASSERT(mPresContext->StyleSet()->IsGecko(),
"ElementRestyler should only be used with a Gecko-flavored "
"style backend");
return mPresContext->StyleSet()->AsGecko();
}
AutoDisplayContentsAncestorPusher::AutoDisplayContentsAncestorPusher(
TreeMatchContext& aTreeMatchContext, nsPresContext* aPresContext,
nsIContent* aParent)
: mTreeMatchContext(aTreeMatchContext)
, mPresContext(aPresContext)
{
if (aParent) {
nsFrameManager* fm = mPresContext->FrameManager();
// Push display:contents mAncestors onto mTreeMatchContext.
for (nsIContent* p = aParent; p && fm->GetDisplayContentsStyleFor(p);
p = p->GetParent()) {
mAncestors.AppendElement(p->AsElement());
}
bool hasFilter = mTreeMatchContext.mAncestorFilter.HasFilter();
nsTArray<mozilla::dom::Element*>::size_type i = mAncestors.Length();
while (i--) {
if (hasFilter) {
mTreeMatchContext.mAncestorFilter.PushAncestor(mAncestors[i]);
}
mTreeMatchContext.PushStyleScope(mAncestors[i]);
}
}
}
AutoDisplayContentsAncestorPusher::~AutoDisplayContentsAncestorPusher()
{
// Pop the ancestors we pushed in the CTOR, if any.
typedef nsTArray<mozilla::dom::Element*>::size_type sz;
sz len = mAncestors.Length();
bool hasFilter = mTreeMatchContext.mAncestorFilter.HasFilter();
for (sz i = 0; i < len; ++i) {
if (hasFilter) {
mTreeMatchContext.mAncestorFilter.PopAncestor();
}
mTreeMatchContext.PopStyleScope(mAncestors[i]);
}
}
#ifdef RESTYLE_LOGGING
uint32_t
GeckoRestyleManager::StructsToLog()
{
static bool initialized = false;
static uint32_t structs;
if (!initialized) {
structs = 0;
const char* value = getenv("MOZ_DEBUG_RESTYLE_STRUCTS");
if (value) {
nsCString s(value);
while (!s.IsEmpty()) {
int32_t index = s.FindChar(',');
nsStyleStructID sid;
bool found;
if (index == -1) {
found = nsStyleContext::LookupStruct(s, sid);
s.Truncate();
} else {
found = nsStyleContext::LookupStruct(Substring(s, 0, index), sid);
s = Substring(s, index + 1);
}
if (found) {
structs |= nsCachedStyleData::GetBitForSID(sid);
}
}
}
initialized = true;
}
return structs;
}
#endif
#ifdef DEBUG
/* static */ nsCString
GeckoRestyleManager::StructNamesToString(uint32_t aSIDs)
{
nsCString result;
bool any = false;
for (nsStyleStructID sid = nsStyleStructID(0);
sid < nsStyleStructID_Length;
sid = nsStyleStructID(sid + 1)) {
if (aSIDs & nsCachedStyleData::GetBitForSID(sid)) {
if (any) {
result.AppendLiteral(",");
}
result.AppendPrintf("%s", nsStyleContext::StructName(sid));
any = true;
}
}
return result;
}
/* static */ nsCString
ElementRestyler::RestyleResultToString(RestyleResult aRestyleResult)
{
nsCString result;
switch (aRestyleResult) {
case RestyleResult::eStop:
result.AssignLiteral("RestyleResult::eStop");
break;
case RestyleResult::eStopWithStyleChange:
result.AssignLiteral("RestyleResult::eStopWithStyleChange");
break;
case RestyleResult::eContinue:
result.AssignLiteral("RestyleResult::eContinue");
break;
case RestyleResult::eContinueAndForceDescendants:
result.AssignLiteral("RestyleResult::eContinueAndForceDescendants");
break;
default:
MOZ_ASSERT(aRestyleResult == RestyleResult::eNone,
"Unexpected RestyleResult");
}
return result;
}
#endif
} // namespace mozilla
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