gecko-dev/layout/style/GeckoStyleContext.cpp

1185 строки
42 KiB
C++

/* -*- 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/. */
#include "mozilla/GeckoStyleContext.h"
#include "CSSVariableImageTable.h"
#include "nsStyleConsts.h"
#include "nsStyleStruct.h"
#include "nsPresContext.h"
#include "nsRuleNode.h"
#include "nsStyleContextInlines.h"
#include "nsIFrame.h"
#include "nsLayoutUtils.h"
#include "mozilla/ReflowInput.h"
#include "RubyUtils.h"
using namespace mozilla;
#ifdef DEBUG
// Whether to perform expensive assertions in the nsStyleContext destructor.
static bool sExpensiveStyleStructAssertionsEnabled;
/* static */ void
GeckoStyleContext::Initialize()
{
Preferences::AddBoolVarCache(
&sExpensiveStyleStructAssertionsEnabled,
"layout.css.expensive-style-struct-assertions.enabled");
}
#endif
GeckoStyleContext::GeckoStyleContext(GeckoStyleContext* aParent,
nsIAtom* aPseudoTag,
CSSPseudoElementType aPseudoType,
already_AddRefed<nsRuleNode> aRuleNode,
bool aSkipParentDisplayBasedStyleFixup)
: nsStyleContext(aPseudoTag, aPseudoType)
, mCachedResetData(nullptr)
, mRefCnt(0)
, mChild(nullptr)
, mEmptyChild(nullptr)
, mRuleNode(Move(aRuleNode))
, mParent(aParent)
#ifdef DEBUG
, mComputingStruct(nsStyleStructID_None)
#endif
{
mBits |= NS_STYLE_CONTEXT_IS_GECKO;
if (aParent) {
#ifdef DEBUG
nsRuleNode *r1 = mParent->RuleNode(), *r2 = mRuleNode;
while (r1->GetParent())
r1 = r1->GetParent();
while (r2->GetParent())
r2 = r2->GetParent();
NS_ASSERTION(r1 == r2, "must be in the same rule tree as parent");
#endif
} else {
PresContext()->PresShell()->StyleSet()->RootStyleContextAdded();
}
mRuleNode->SetUsedDirectly(); // before ApplyStyleFixups()!
// FinishConstruction() calls AddChild which needs these
// to be initialized!
mNextSibling = this;
mPrevSibling = this;
FinishConstruction();
ApplyStyleFixups(aSkipParentDisplayBasedStyleFixup);
}
// Overloaded new operator. Initializes the memory to 0 and relies on an arena
// (which comes from the presShell) to perform the allocation.
void*
GeckoStyleContext::operator new(size_t sz, nsPresContext* aPresContext)
{
MOZ_ASSERT(sz == sizeof(GeckoStyleContext));
// Check the recycle list first.
return aPresContext->PresShell()->
AllocateByObjectID(eArenaObjectID_GeckoStyleContext, sz);
}
// Overridden to prevent the global delete from being called, since the memory
// came out of an nsIArena instead of the global delete operator's heap.
void
GeckoStyleContext::Destroy()
{
// Get the pres context.
RefPtr<nsPresContext> presContext = PresContext();
// Call our destructor.
this->~GeckoStyleContext();
// Don't let the memory be freed, since it will be recycled
// instead. Don't call the global operator delete.
presContext->PresShell()->
FreeByObjectID(eArenaObjectID_GeckoStyleContext, this);
}
GeckoStyleContext::~GeckoStyleContext()
{
nsPresContext *presContext = PresContext();
#ifdef DEBUG
NS_ASSERTION(HasNoChildren(), "destructing context with children");
if (sExpensiveStyleStructAssertionsEnabled) {
// Assert that the style structs we are about to destroy are not referenced
// anywhere else in the style context tree. These checks are expensive,
// which is why they are not enabled by default.
GeckoStyleContext* root = this;
while (root->GetParent()) {
root = root->GetParent();
}
root->AssertStructsNotUsedElsewhere(this,
std::numeric_limits<int32_t>::max());
} else {
// In DEBUG builds when the pref is not enabled, we perform a more limited
// check just of the children of this style context.
this->AssertStructsNotUsedElsewhere(this, 2);
}
nsStyleSet* geckoStyleSet = presContext->PresShell()->StyleSet()->GetAsGecko();
NS_ASSERTION(!geckoStyleSet ||
geckoStyleSet->GetRuleTree() == AsGecko()->RuleNode()->RuleTree() ||
geckoStyleSet->IsInRuleTreeReconstruct(),
"destroying style context from old rule tree too late");
#endif
if (mParent) {
mParent->AsGecko()->RemoveChild(this);
} else {
presContext->StyleSet()->RootStyleContextRemoved();
}
// Free up our data structs.
DestroyCachedStructs(presContext);
CSSVariableImageTable::RemoveAll(this);
}
void
GeckoStyleContext::AddChild(GeckoStyleContext* aChild)
{
NS_ASSERTION(aChild->mPrevSibling == aChild &&
aChild->mNextSibling == aChild,
"child already in a child list");
GeckoStyleContext **listPtr = aChild->mRuleNode->IsRoot() ? &mEmptyChild : &mChild;
if (const nsRuleNode* source = aChild->mRuleNode) {
if (source->IsRoot()) {
listPtr = &mEmptyChild;
}
}
// Explicitly dereference listPtr so that compiler doesn't have to know that mNextSibling
// etc. don't alias with what ever listPtr points at.
GeckoStyleContext *list = *listPtr;
// Insert at the beginning of the list. See also FindChildWithRules.
if (list) {
// Link into existing elements, if there are any.
aChild->mNextSibling = list;
aChild->mPrevSibling = list->mPrevSibling;
list->mPrevSibling->mNextSibling = aChild;
list->mPrevSibling = aChild;
}
(*listPtr) = aChild;
}
void
GeckoStyleContext::MoveTo(GeckoStyleContext* aNewParent)
{
MOZ_ASSERT(aNewParent != mParent);
// This function shouldn't be getting called if the parents have different
// values for some flags in mBits (unless the flag is also set on this style
// context) because if that were the case we would need to recompute those
// bits for |this|.
#define CHECK_FLAG(bit_) \
MOZ_ASSERT((mParent->AsGecko()->mBits & (bit_)) == \
(aNewParent->mBits & (bit_)) || (mBits & (bit_)), \
"MoveTo cannot be called if " #bit_ " value on old and new " \
"style context parents do not match, unless the flag is set " \
"on this style context");
CHECK_FLAG(NS_STYLE_HAS_PSEUDO_ELEMENT_DATA)
CHECK_FLAG(NS_STYLE_IN_DISPLAY_NONE_SUBTREE)
CHECK_FLAG(NS_STYLE_HAS_TEXT_DECORATION_LINES)
CHECK_FLAG(NS_STYLE_RELEVANT_LINK_VISITED)
#undef CHECK_FLAG
// Assertions checking for visited style are just to avoid some tricky
// cases we can't be bothered handling at the moment.
MOZ_ASSERT(!IsStyleIfVisited());
MOZ_ASSERT(!mParent->IsStyleIfVisited());
MOZ_ASSERT(!aNewParent->IsStyleIfVisited());
auto* styleIfVisited = GetStyleIfVisited();
MOZ_ASSERT(!styleIfVisited || styleIfVisited->mParent == mParent);
if (mParent->HasChildThatUsesResetStyle()) {
aNewParent->AddStyleBit(NS_STYLE_HAS_CHILD_THAT_USES_RESET_STYLE);
}
mParent->RemoveChild(this);
mParent = aNewParent;
mParent->AddChild(this);
if (styleIfVisited) {
styleIfVisited->mParent->RemoveChild(styleIfVisited);
styleIfVisited->mParent = aNewParent;
styleIfVisited->mParent->AddChild(styleIfVisited);
}
}
void
GeckoStyleContext::RemoveChild(GeckoStyleContext* aChild)
{
NS_PRECONDITION(nullptr != aChild && this == aChild->mParent, "bad argument");
MOZ_ASSERT(aChild->mRuleNode, "child context should have rule node");
GeckoStyleContext **list = aChild->mRuleNode->IsRoot() ? &mEmptyChild : &mChild;
if (aChild->mPrevSibling != aChild) { // has siblings
if ((*list) == aChild) {
(*list) = (*list)->mNextSibling;
}
}
else {
NS_ASSERTION((*list) == aChild, "bad sibling pointers");
(*list) = nullptr;
}
aChild->mPrevSibling->mNextSibling = aChild->mNextSibling;
aChild->mNextSibling->mPrevSibling = aChild->mPrevSibling;
aChild->mNextSibling = aChild;
aChild->mPrevSibling = aChild;
}
#ifdef DEBUG
void
GeckoStyleContext::ListDescendants(FILE* out, int32_t aIndent)
{
if (nullptr != mChild) {
GeckoStyleContext* child = mChild;
do {
child->List(out, aIndent + 1, true);
child = child->mNextSibling;
} while (mChild != child);
}
if (nullptr != mEmptyChild) {
GeckoStyleContext* child = mEmptyChild;
do {
child->List(out, aIndent + 1, true);
child = child->mNextSibling;
} while (mEmptyChild != child);
}
}
#endif
void
GeckoStyleContext::ClearCachedInheritedStyleDataOnDescendants(uint32_t aStructs)
{
if (mChild) {
GeckoStyleContext* child = mChild;
do {
child->DoClearCachedInheritedStyleDataOnDescendants(aStructs);
child = child->mNextSibling;
} while (mChild != child);
}
if (mEmptyChild) {
GeckoStyleContext* child = mEmptyChild;
do {
child->DoClearCachedInheritedStyleDataOnDescendants(aStructs);
child = child->mNextSibling;
} while (mEmptyChild != child);
}
}
void
GeckoStyleContext::DoClearCachedInheritedStyleDataOnDescendants(uint32_t aStructs)
{
NS_ASSERTION(mFrameRefCnt == 0, "frame still referencing style context");
for (nsStyleStructID i = nsStyleStructID_Inherited_Start;
i < nsStyleStructID_Inherited_Start + nsStyleStructID_Inherited_Count;
i = nsStyleStructID(i + 1)) {
uint32_t bit = nsCachedStyleData::GetBitForSID(i);
if (aStructs & bit) {
if (!(mBits & bit) && mCachedInheritedData.mStyleStructs[i]) {
aStructs &= ~bit;
} else {
mCachedInheritedData.mStyleStructs[i] = nullptr;
}
}
}
if (mCachedResetData) {
for (nsStyleStructID i = nsStyleStructID_Reset_Start;
i < nsStyleStructID_Reset_Start + nsStyleStructID_Reset_Count;
i = nsStyleStructID(i + 1)) {
uint32_t bit = nsCachedStyleData::GetBitForSID(i);
if (aStructs & bit) {
if (!(mBits & bit) && mCachedResetData->mStyleStructs[i]) {
aStructs &= ~bit;
} else {
mCachedResetData->mStyleStructs[i] = nullptr;
}
}
}
}
if (aStructs == 0) {
return;
}
ClearCachedInheritedStyleDataOnDescendants(aStructs);
}
already_AddRefed<GeckoStyleContext>
GeckoStyleContext::FindChildWithRules(const nsIAtom* aPseudoTag,
nsRuleNode* aSource,
nsRuleNode* aSourceIfVisited,
bool aRelevantLinkVisited)
{
uint32_t threshold = 10; // The # of siblings we're willing to examine
// before just giving this whole thing up.
RefPtr<GeckoStyleContext> result;
MOZ_ASSERT(aSource);
GeckoStyleContext *list = aSource->IsRoot() ? mEmptyChild : mChild;
if (list) {
GeckoStyleContext *child = list;
do {
if (child->RuleNode() == aSource &&
child->mPseudoTag == aPseudoTag &&
!child->IsStyleIfVisited() &&
child->RelevantLinkVisited() == aRelevantLinkVisited) {
bool match = false;
if (aSourceIfVisited) {
match = child->GetStyleIfVisited() &&
child->GetStyleIfVisited()->RuleNode() == aSourceIfVisited;
} else {
match = !child->GetStyleIfVisited();
}
if (match && !(child->mBits & NS_STYLE_INELIGIBLE_FOR_SHARING)) {
result = child;
break;
}
}
child = child->mNextSibling;
threshold--;
if (threshold == 0)
break;
} while (child != list);
}
if (result) {
if (result != list) {
// Move result to the front of the list.
RemoveChild(result);
AddChild(result);
}
result->mBits |= NS_STYLE_IS_SHARED;
}
return result.forget();
}
// This is an evil evil function, since it forces you to alloc your own separate copy of
// style data! Do not use this function unless you absolutely have to! You should avoid
// this at all costs! -dwh
void*
GeckoStyleContext::GetUniqueStyleData(const nsStyleStructID& aSID)
{
// If we already own the struct and no kids could depend on it, then
// just return it. (We leak in this case if there are kids -- and this
// function really shouldn't be called for style contexts that could
// have kids depending on the data. ClearStyleData would be OK, but
// this test for no mChild or mEmptyChild doesn't catch that case.)
const void *current = StyleData(aSID);
if (!mChild && !mEmptyChild &&
!(mBits & nsCachedStyleData::GetBitForSID(aSID)) &&
GetCachedStyleData(aSID))
return const_cast<void*>(current);
void* result;
nsPresContext *presContext = PresContext();
switch (aSID) {
#define UNIQUE_CASE(c_) \
case eStyleStruct_##c_: \
result = new (presContext) nsStyle##c_( \
* static_cast<const nsStyle##c_ *>(current)); \
break;
UNIQUE_CASE(Font)
UNIQUE_CASE(Display)
UNIQUE_CASE(Position)
UNIQUE_CASE(Text)
UNIQUE_CASE(TextReset)
UNIQUE_CASE(Visibility)
#undef UNIQUE_CASE
default:
NS_ERROR("Struct type not supported. Please find another way to do this if you can!");
return nullptr;
}
SetStyle(aSID, result);
mBits &= ~static_cast<uint64_t>(nsCachedStyleData::GetBitForSID(aSID));
return result;
}
// This is an evil function, but less evil than GetUniqueStyleData. It
// creates an empty style struct for this nsStyleContext.
void*
GeckoStyleContext::CreateEmptyStyleData(const nsStyleStructID& aSID)
{
MOZ_ASSERT(!mChild && !mEmptyChild &&
!(mBits & nsCachedStyleData::GetBitForSID(aSID)) &&
!GetCachedStyleData(aSID),
"This style should not have been computed");
void* result;
nsPresContext* presContext = PresContext();
switch (aSID) {
#define UNIQUE_CASE(c_) \
case eStyleStruct_##c_: \
result = new (presContext) nsStyle##c_(presContext); \
break;
UNIQUE_CASE(Border)
UNIQUE_CASE(Padding)
#undef UNIQUE_CASE
default:
NS_ERROR("Struct type not supported.");
return nullptr;
}
// The new struct is owned by this style context, but that we don't
// need to clear the bit in mBits because we've asserted that at the
// top of this function.
SetStyle(aSID, result);
return result;
}
void
GeckoStyleContext::SetIneligibleForSharing()
{
if (mBits & NS_STYLE_INELIGIBLE_FOR_SHARING) {
return;
}
mBits |= NS_STYLE_INELIGIBLE_FOR_SHARING;
if (mChild) {
GeckoStyleContext* child = mChild;
do {
child->SetIneligibleForSharing();
child = child->mNextSibling;
} while (mChild != child);
}
if (mEmptyChild) {
GeckoStyleContext* child = mEmptyChild;
do {
child->SetIneligibleForSharing();
child = child->mNextSibling;
} while (mEmptyChild != child);
}
}
#ifdef RESTYLE_LOGGING
nsCString
GeckoStyleContext::GetCachedStyleDataAsString(uint32_t aStructs)
{
nsCString structs;
for (nsStyleStructID i = nsStyleStructID(0);
i < nsStyleStructID_Length;
i = nsStyleStructID(i + 1)) {
if (aStructs & nsCachedStyleData::GetBitForSID(i)) {
const void* data = GetCachedStyleData(i);
if (!structs.IsEmpty()) {
structs.Append(' ');
}
structs.AppendPrintf("%s=%p", StructName(i), data);
if (HasCachedDependentStyleData(i)) {
structs.AppendLiteral("(dependent)");
} else {
structs.AppendLiteral("(owned)");
}
}
}
return structs;
}
int32_t&
GeckoStyleContext::LoggingDepth()
{
static int32_t depth = 0;
return depth;
}
void
GeckoStyleContext::LogStyleContextTree(int32_t aLoggingDepth, uint32_t aStructs)
{
LoggingDepth() = aLoggingDepth;
LogStyleContextTree(true, aStructs);
}
void
GeckoStyleContext::LogStyleContextTree(bool aFirst, uint32_t aStructs)
{
nsCString structs = GetCachedStyleDataAsString(aStructs);
if (!structs.IsEmpty()) {
structs.Append(' ');
}
nsCString pseudo;
if (mPseudoTag) {
nsAutoString pseudoTag;
mPseudoTag->ToString(pseudoTag);
AppendUTF16toUTF8(pseudoTag, pseudo);
pseudo.Append(' ');
}
nsCString flags;
if (IsStyleIfVisited()) {
flags.AppendLiteral("IS_STYLE_IF_VISITED ");
}
if (HasChildThatUsesGrandancestorStyle()) {
flags.AppendLiteral("CHILD_USES_GRANDANCESTOR_STYLE ");
}
if (IsShared()) {
flags.AppendLiteral("IS_SHARED ");
}
nsCString parent;
if (aFirst) {
parent.AppendPrintf("parent=%p ", mParent.get());
}
LOG_RESTYLE("%p(%d) %s%s%s%s",
this, mRefCnt,
structs.get(), pseudo.get(), flags.get(), parent.get());
LOG_RESTYLE_INDENT();
if (nullptr != mChild) {
GeckoStyleContext* child = mChild;
do {
child->LogStyleContextTree(false, aStructs);
child = child->mNextSibling;
} while (mChild != child);
}
if (nullptr != mEmptyChild) {
GeckoStyleContext* child = mEmptyChild;
do {
child->LogStyleContextTree(false, aStructs);
child = child->mNextSibling;
} while (mEmptyChild != child);
}
}
#endif
static bool
ShouldSuppressLineBreak(const nsStyleContext* aContext,
const nsStyleDisplay* aDisplay,
const nsStyleContext* aParentContext,
const nsStyleDisplay* aParentDisplay)
{
// The display change should only occur for "in-flow" children
if (aDisplay->IsOutOfFlowStyle()) {
return false;
}
// Display value of any anonymous box should not be touched. In most
// cases, anonymous boxes are actually not in ruby frame, but instead,
// some other frame with a ruby display value. Non-element pseudos
// which represents text frames, as well as ruby pseudos are excluded
// because we still want to set the flag for them.
if ((aContext->GetPseudoType() == CSSPseudoElementType::InheritingAnonBox ||
aContext->GetPseudoType() == CSSPseudoElementType::NonInheritingAnonBox) &&
!nsCSSAnonBoxes::IsNonElement(aContext->GetPseudo()) &&
!RubyUtils::IsRubyPseudo(aContext->GetPseudo())) {
return false;
}
if (aParentContext->ShouldSuppressLineBreak()) {
// Line break suppressing bit is propagated to any children of
// line participants, which include inline, contents, and inline
// ruby boxes.
if (aParentDisplay->mDisplay == mozilla::StyleDisplay::Inline ||
aParentDisplay->mDisplay == mozilla::StyleDisplay::Contents ||
aParentDisplay->mDisplay == mozilla::StyleDisplay::Ruby ||
aParentDisplay->mDisplay == mozilla::StyleDisplay::RubyBaseContainer) {
return true;
}
}
// Any descendant of ruby level containers is non-breakable, but
// the level containers themselves are breakable. We have to check
// the container display type against all ruby display type here
// because any of the ruby boxes could be anonymous.
// Note that, when certain HTML tags, e.g. form controls, have ruby
// level container display type, they could also escape from this flag
// while they shouldn't. However, it is generally fine since they
// won't usually break the assertion that there is no line break
// inside ruby, because:
// 1. their display types, the ruby level container types, are inline-
// outside, which means they won't cause any forced line break; and
// 2. they never start an inline span, which means their children, if
// any, won't be able to break the line its ruby ancestor lays; and
// 3. their parent frame is always a ruby content frame (due to
// anonymous ruby box generation), which makes line layout suppress
// any optional line break around this frame.
// However, there is one special case which is BR tag, because it
// directly affects the line layout. This case is handled by the BR
// frame which checks the flag of its parent frame instead of itself.
if ((aParentDisplay->IsRubyDisplayType() &&
aDisplay->mDisplay != mozilla::StyleDisplay::RubyBaseContainer &&
aDisplay->mDisplay != mozilla::StyleDisplay::RubyTextContainer) ||
// Since ruby base and ruby text may exist themselves without any
// non-anonymous frame outside, we should also check them.
aDisplay->mDisplay == mozilla::StyleDisplay::RubyBase ||
aDisplay->mDisplay == mozilla::StyleDisplay::RubyText) {
return true;
}
return false;
}
void
GeckoStyleContext::FinishConstruction()
{
MOZ_ASSERT(RuleNode());
if (mParent) {
mParent->AddChild(this);
}
SetStyleBits();
}
void
GeckoStyleContext::SetStyleBits()
{
if ((mParent && mParent->HasPseudoElementData()) || IsPseudoElement()) {
AddStyleBit(NS_STYLE_HAS_PSEUDO_ELEMENT_DATA);
}
// Set the NS_STYLE_IN_DISPLAY_NONE_SUBTREE bit
const nsStyleDisplay* disp = StyleDisplay();
if ((mParent && mParent->IsInDisplayNoneSubtree()) ||
disp->mDisplay == mozilla::StyleDisplay::None) {
AddStyleBit(NS_STYLE_IN_DISPLAY_NONE_SUBTREE);
}
// Mark text combined for text-combine-upright, as needed.
if (mPseudoTag == nsCSSAnonBoxes::mozText && mParent &&
mParent->StyleVisibility()->mWritingMode !=
NS_STYLE_WRITING_MODE_HORIZONTAL_TB &&
mParent->StyleText()->mTextCombineUpright ==
NS_STYLE_TEXT_COMBINE_UPRIGHT_ALL) {
AddStyleBit(NS_STYLE_IS_TEXT_COMBINED);
}
}
// Flex & grid containers blockify their children.
// "The display value of a flex item is blockified"
// https://drafts.csswg.org/css-flexbox-1/#flex-items
// "The display value of a grid item is blockified"
// https://drafts.csswg.org/css-grid/#grid-items
static bool
ShouldBlockifyChildren(const nsStyleDisplay* aStyleDisp)
{
auto displayVal = aStyleDisp->mDisplay;
return mozilla::StyleDisplay::Flex == displayVal ||
mozilla::StyleDisplay::InlineFlex == displayVal ||
mozilla::StyleDisplay::Grid == displayVal ||
mozilla::StyleDisplay::InlineGrid == displayVal;
}
#ifdef DEBUG
void
GeckoStyleContext::AssertStructsNotUsedElsewhere(
GeckoStyleContext* aDestroyingContext,
int32_t aLevels) const
{
if (aLevels == 0) {
return;
}
void* data;
if (mBits & NS_STYLE_IS_GOING_AWAY) {
return;
}
if (this != aDestroyingContext) {
nsInheritedStyleData& destroyingInheritedData =
aDestroyingContext->mCachedInheritedData;
#define STYLE_STRUCT_INHERITED(name_, checkdata_cb) \
data = destroyingInheritedData.mStyleStructs[eStyleStruct_##name_]; \
if (data && \
!(aDestroyingContext->mBits & NS_STYLE_INHERIT_BIT(name_)) && \
(mCachedInheritedData.mStyleStructs[eStyleStruct_##name_] == data)) { \
printf_stderr("style struct %p found on style context %p\n", data, this);\
nsString url; \
nsresult rv = PresContext()->Document()->GetURL(url); \
if (NS_SUCCEEDED(rv)) { \
printf_stderr(" in %s\n", NS_ConvertUTF16toUTF8(url).get()); \
} \
MOZ_ASSERT(false, "destroying " #name_ " style struct still present " \
"in style context tree"); \
}
#define STYLE_STRUCT_RESET(name_, checkdata_cb)
#include "nsStyleStructList.h"
#undef STYLE_STRUCT_INHERITED
#undef STYLE_STRUCT_RESET
if (mCachedResetData) {
nsResetStyleData* destroyingResetData =
aDestroyingContext->mCachedResetData;
if (destroyingResetData) {
#define STYLE_STRUCT_INHERITED(name_, checkdata_cb_)
#define STYLE_STRUCT_RESET(name_, checkdata_cb) \
data = destroyingResetData->mStyleStructs[eStyleStruct_##name_]; \
if (data && \
!(aDestroyingContext->mBits & NS_STYLE_INHERIT_BIT(name_)) && \
(mCachedResetData->mStyleStructs[eStyleStruct_##name_] == data)) { \
printf_stderr("style struct %p found on style context %p\n", data, \
this); \
nsString url; \
nsresult rv = PresContext()->Document()->GetURL(url); \
if (NS_SUCCEEDED(rv)) { \
printf_stderr(" in %s\n", NS_ConvertUTF16toUTF8(url).get()); \
} \
MOZ_ASSERT(false, "destroying " #name_ " style struct still present "\
"in style context tree"); \
}
#include "nsStyleStructList.h"
#undef STYLE_STRUCT_INHERITED
#undef STYLE_STRUCT_RESET
}
}
}
if (mChild) {
const GeckoStyleContext* child = mChild;
do {
child->AssertStructsNotUsedElsewhere(aDestroyingContext, aLevels - 1);
child = child->mNextSibling;
} while (child != mChild);
}
if (mEmptyChild) {
const GeckoStyleContext* child = mEmptyChild;
do {
child->AssertStructsNotUsedElsewhere(aDestroyingContext, aLevels - 1);
child = child->mNextSibling;
} while (child != mEmptyChild);
}
}
#endif
void
GeckoStyleContext::ApplyStyleFixups(bool aSkipParentDisplayBasedStyleFixup)
{
#define GET_UNIQUE_STYLE_DATA(name_) \
static_cast<nsStyle##name_*>(GetUniqueStyleData(eStyleStruct_##name_))
// CSS Inline Layout Level 3 - 3.5 Sizing Initial Letters:
// For an N-line drop initial in a Western script, the cap-height of the
// letter needs to be (N – 1) times the line-height, plus the cap-height
// of the surrounding text.
if (mPseudoTag == nsCSSPseudoElements::firstLetter) {
const nsStyleTextReset* textReset = StyleTextReset();
if (textReset->mInitialLetterSize != 0.0f) {
GeckoStyleContext* containerSC = GetParent();
const nsStyleDisplay* containerDisp = containerSC->StyleDisplay();
while (containerDisp->mDisplay == mozilla::StyleDisplay::Contents) {
if (!containerSC->GetParent()) {
break;
}
containerSC = containerSC->GetParent();
containerDisp = containerSC->StyleDisplay();
}
nscoord containerLH =
ReflowInput::CalcLineHeight(nullptr, containerSC, NS_AUTOHEIGHT, 1.0f);
RefPtr<nsFontMetrics> containerFM =
nsLayoutUtils::GetFontMetricsForStyleContext(containerSC);
MOZ_ASSERT(containerFM, "Should have fontMetrics!!");
nscoord containerCH = containerFM->CapHeight();
RefPtr<nsFontMetrics> firstLetterFM =
nsLayoutUtils::GetFontMetricsForStyleContext(this);
MOZ_ASSERT(firstLetterFM, "Should have fontMetrics!!");
nscoord firstLetterCH = firstLetterFM->CapHeight();
nsStyleFont* mutableStyleFont = GET_UNIQUE_STYLE_DATA(Font);
float invCapHeightRatio =
mutableStyleFont->mFont.size / NSCoordToFloat(firstLetterCH);
mutableStyleFont->mFont.size =
NSToCoordRound(((textReset->mInitialLetterSize - 1) * containerLH +
containerCH) *
invCapHeightRatio);
}
}
// Change writing mode of text frame for text-combine-upright. We use
// style structs of the parent to avoid triggering computation before
// we change the writing mode.
// It is safe to look at the parent's style because we are looking at
// inherited properties, and ::-moz-text never matches any rules.
if (mPseudoTag == nsCSSAnonBoxes::mozText && mParent &&
mParent->StyleVisibility()->mWritingMode !=
NS_STYLE_WRITING_MODE_HORIZONTAL_TB &&
mParent->StyleText()->mTextCombineUpright ==
NS_STYLE_TEXT_COMBINE_UPRIGHT_ALL) {
MOZ_ASSERT(!PeekStyleVisibility(), "If StyleVisibility was already "
"computed, some properties may have been computed "
"incorrectly based on the old writing mode value");
nsStyleVisibility* mutableVis = GET_UNIQUE_STYLE_DATA(Visibility);
mutableVis->mWritingMode = NS_STYLE_WRITING_MODE_HORIZONTAL_TB;
}
// See if we have any text decorations.
// First see if our parent has text decorations. If our parent does, then we inherit the bit.
if (mParent && mParent->HasTextDecorationLines()) {
AddStyleBit(NS_STYLE_HAS_TEXT_DECORATION_LINES);
} else {
// We might have defined a decoration.
if (StyleTextReset()->HasTextDecorationLines()) {
AddStyleBit(NS_STYLE_HAS_TEXT_DECORATION_LINES);
}
}
// CSS 2.1 10.1: Propagate the root element's 'direction' to the ICB.
// (PageContentFrame/CanvasFrame etc will inherit 'direction')
if (mPseudoTag == nsCSSAnonBoxes::viewport) {
nsPresContext* presContext = PresContext();
mozilla::dom::Element* docElement = presContext->Document()->GetRootElement();
if (docElement) {
RefPtr<nsStyleContext> rootStyle =
presContext->StyleSet()->AsGecko()->ResolveStyleFor(docElement, nullptr);
auto dir = rootStyle->StyleVisibility()->mDirection;
if (dir != StyleVisibility()->mDirection) {
nsStyleVisibility* uniqueVisibility = GET_UNIQUE_STYLE_DATA(Visibility);
uniqueVisibility->mDirection = dir;
}
}
}
// Correct tables.
const nsStyleDisplay* disp = StyleDisplay();
if (disp->mDisplay == mozilla::StyleDisplay::Table) {
// -moz-center and -moz-right are used for HTML's alignment
// This is covering the <div align="right"><table>...</table></div> case.
// In this case, we don't want to inherit the text alignment into the table.
const nsStyleText* text = StyleText();
if (text->mTextAlign == NS_STYLE_TEXT_ALIGN_MOZ_LEFT ||
text->mTextAlign == NS_STYLE_TEXT_ALIGN_MOZ_CENTER ||
text->mTextAlign == NS_STYLE_TEXT_ALIGN_MOZ_RIGHT)
{
nsStyleText* uniqueText = GET_UNIQUE_STYLE_DATA(Text);
uniqueText->mTextAlign = NS_STYLE_TEXT_ALIGN_START;
}
}
// Fixup the "justify-items: auto" value based on our parent style here if
// needed.
//
// Note that this only pulls a unique struct in the case the parent has the
// "legacy" modifier (which is not the default), and the computed value would
// change as a result.
//
// We check the parent first just to avoid unconditionally pulling the
// nsStylePosition struct on every style context.
if (mParent &&
mParent->StylePosition()->mJustifyItems & NS_STYLE_JUSTIFY_LEGACY &&
StylePosition()->mSpecifiedJustifyItems == NS_STYLE_JUSTIFY_AUTO &&
StylePosition()->mJustifyItems != mParent->StylePosition()->mJustifyItems) {
nsStylePosition* uniquePosition = GET_UNIQUE_STYLE_DATA(Position);
uniquePosition->mJustifyItems = mParent->StylePosition()->mJustifyItems;
}
// CSS2.1 section 9.2.4 specifies fixups for the 'display' property of
// the root element. We can't implement them in nsRuleNode because we
// don't want to store all display structs that aren't 'block',
// 'inline', or 'table' in the style context tree on the off chance
// that the root element has its style reresolved later. So do them
// here if needed, by changing the style data, so that other code
// doesn't get confused by looking at the style data.
if (!mParent &&
// We don't want to blockify various anon boxes that just happen to not
// inherit from anything. So restrict blockification only to actual
// elements, the viewport (which should be block anyway, but in SVG
// document's isn't because we lazy-load ua.css there), and the ::backdrop
// pseudo-element. This last is explicitly allowed to have any specified
// display type in the spec, but computes to a blockified display type per
// various provisions of
// https://fullscreen.spec.whatwg.org/#new-stacking-layer
(!mPseudoTag ||
mPseudoTag == nsCSSAnonBoxes::viewport ||
mPseudoTag == nsCSSPseudoElements::backdrop)) {
auto displayVal = disp->mDisplay;
if (displayVal != mozilla::StyleDisplay::Contents) {
nsRuleNode::EnsureBlockDisplay(displayVal, true);
} else {
// http://dev.w3.org/csswg/css-display/#transformations
// "... a display-outside of 'contents' computes to block-level
// on the root element."
displayVal = mozilla::StyleDisplay::Block;
}
if (displayVal != disp->mDisplay) {
nsStyleDisplay* mutable_display = GET_UNIQUE_STYLE_DATA(Display);
disp = mutable_display;
// If we're in this code, then mOriginalDisplay doesn't matter
// for purposes of the cascade (because this nsStyleDisplay
// isn't living in the ruletree anyway), and for determining
// hypothetical boxes it's better to have mOriginalDisplay
// matching mDisplay here.
mutable_display->mOriginalDisplay = mutable_display->mDisplay =
displayVal;
}
}
// Adjust the "display" values of flex and grid items (but not for raw text
// or placeholders). CSS3 Flexbox section 4 says:
// # The computed 'display' of a flex item is determined
// # by applying the table in CSS 2.1 Chapter 9.7.
// ...which converts inline-level elements to their block-level equivalents.
// Any block-level element directly contained by elements with ruby display
// values are converted to their inline-level equivalents.
if (!aSkipParentDisplayBasedStyleFixup && mParent) {
// Skip display:contents ancestors to reach the potential container.
// (If there are only display:contents ancestors between this node and
// a flex/grid container ancestor, then this node is a flex/grid item, since
// its parent *in the frame tree* will be the flex/grid container. So we treat
// it like a flex/grid item here.)
GeckoStyleContext* containerContext = GetParent();
const nsStyleDisplay* containerDisp = containerContext->StyleDisplay();
while (containerDisp->mDisplay == mozilla::StyleDisplay::Contents) {
if (!containerContext->GetParent()) {
break;
}
containerContext = containerContext->GetParent();
containerDisp = containerContext->StyleDisplay();
}
if (ShouldBlockifyChildren(containerDisp) &&
!nsCSSAnonBoxes::IsNonElement(GetPseudo())) {
// NOTE: Technically, we shouldn't modify the 'display' value of
// positioned elements, since they aren't flex/grid items. However,
// we don't need to worry about checking for that, because if we're
// positioned, we'll have already been through a call to
// EnsureBlockDisplay() in nsRuleNode, so this call here won't change
// anything. So we're OK.
auto displayVal = disp->mDisplay;
nsRuleNode::EnsureBlockDisplay(displayVal);
if (displayVal != disp->mDisplay) {
NS_ASSERTION(!disp->IsAbsolutelyPositionedStyle(),
"We shouldn't be changing the display value of "
"positioned content (and we should have already "
"converted its display value to be block-level...)");
nsStyleDisplay* mutable_display = GET_UNIQUE_STYLE_DATA(Display);
disp = mutable_display;
mutable_display->mDisplay = displayVal;
}
}
}
// Note: This must come after the blockification above, otherwise we fail
// the grid-item-blockifying-001.html reftest.
if (mParent && ::ShouldSuppressLineBreak(this, disp, mParent,
mParent->StyleDisplay())) {
mBits |= NS_STYLE_SUPPRESS_LINEBREAK;
auto displayVal = disp->mDisplay;
nsRuleNode::EnsureInlineDisplay(displayVal);
if (displayVal != disp->mDisplay) {
nsStyleDisplay* mutable_display = GET_UNIQUE_STYLE_DATA(Display);
disp = mutable_display;
mutable_display->mDisplay = displayVal;
}
}
// Suppress border/padding of ruby level containers
if (disp->mDisplay == mozilla::StyleDisplay::RubyBaseContainer ||
disp->mDisplay == mozilla::StyleDisplay::RubyTextContainer) {
CreateEmptyStyleData(eStyleStruct_Border);
CreateEmptyStyleData(eStyleStruct_Padding);
}
if (disp->IsRubyDisplayType()) {
// Per CSS Ruby spec section Bidi Reordering, for all ruby boxes,
// the 'normal' and 'embed' values of 'unicode-bidi' should compute to
// 'isolate', and 'bidi-override' should compute to 'isolate-override'.
const nsStyleTextReset* textReset = StyleTextReset();
uint8_t unicodeBidi = textReset->mUnicodeBidi;
if (unicodeBidi == NS_STYLE_UNICODE_BIDI_NORMAL ||
unicodeBidi == NS_STYLE_UNICODE_BIDI_EMBED) {
unicodeBidi = NS_STYLE_UNICODE_BIDI_ISOLATE;
} else if (unicodeBidi == NS_STYLE_UNICODE_BIDI_BIDI_OVERRIDE) {
unicodeBidi = NS_STYLE_UNICODE_BIDI_ISOLATE_OVERRIDE;
}
if (unicodeBidi != textReset->mUnicodeBidi) {
nsStyleTextReset* mutableTextReset = GET_UNIQUE_STYLE_DATA(TextReset);
mutableTextReset->mUnicodeBidi = unicodeBidi;
}
}
/*
* According to https://drafts.csswg.org/css-writing-modes-3/#block-flow:
*
* If a box has a different block flow direction than its containing block:
* * If the box has a specified display of inline, its display computes
* to inline-block. [CSS21]
* ...etc.
*/
if (disp->mDisplay == mozilla::StyleDisplay::Inline &&
!nsCSSAnonBoxes::IsNonElement(mPseudoTag) &&
mParent) {
auto cbContext = GetParent();
while (cbContext->StyleDisplay()->mDisplay == mozilla::StyleDisplay::Contents) {
cbContext = cbContext->GetParent();
}
MOZ_ASSERT(cbContext, "the root context can't have display:contents");
// We don't need the full mozilla::WritingMode value (incorporating dir
// and text-orientation) here; just the writing-mode property is enough.
if (StyleVisibility()->mWritingMode !=
cbContext->StyleVisibility()->mWritingMode) {
nsStyleDisplay* mutable_display = GET_UNIQUE_STYLE_DATA(Display);
disp = mutable_display;
mutable_display->mOriginalDisplay = mutable_display->mDisplay =
mozilla::StyleDisplay::InlineBlock;
}
}
// Compute User Interface style, to trigger loads of cursors
StyleUserInterface();
#undef GET_UNIQUE_STYLE_DATA
}
bool
GeckoStyleContext::HasNoChildren() const
{
return (nullptr == mChild) && (nullptr == mEmptyChild);
}
void
GeckoStyleContext::SetStyle(nsStyleStructID aSID, void* aStruct)
{
// This method should only be called from nsRuleNode! It is not a public
// method!
NS_ASSERTION(aSID >= 0 && aSID < nsStyleStructID_Length, "out of bounds");
// NOTE: nsCachedStyleData::GetStyleData works roughly the same way.
// See the comments there (in nsRuleNode.h) for more details about
// what this is doing and why.
void** dataSlot;
if (nsCachedStyleData::IsReset(aSID)) {
if (!mCachedResetData) {
mCachedResetData = new (PresContext()) nsResetStyleData;
}
dataSlot = &mCachedResetData->mStyleStructs[aSID];
} else {
dataSlot = &mCachedInheritedData.mStyleStructs[aSID];
}
NS_ASSERTION(!*dataSlot || (mBits & nsCachedStyleData::GetBitForSID(aSID)),
"Going to leak style data");
*dataSlot = aStruct;
}
const void*
GeckoStyleContext::StyleData(nsStyleStructID aSID)
{
const void* cachedData = GetCachedStyleData(aSID);
if (cachedData)
return cachedData; // We have computed data stored on this node in the context tree.
// Our style source will take care of it for us.
const void* newData = AsGecko()->RuleNode()->GetStyleData(aSID, this->AsGecko(), true);
if (!nsCachedStyleData::IsReset(aSID)) {
// always cache inherited data on the style context; the rule
// node set the bit in mBits for us if needed.
mCachedInheritedData.mStyleStructs[aSID] = const_cast<void*>(newData);
}
return newData;
}
void
GeckoStyleContext::DestroyCachedStructs(nsPresContext* aPresContext)
{
mCachedInheritedData.DestroyStructs(mBits, aPresContext);
if (mCachedResetData) {
mCachedResetData->Destroy(mBits, aPresContext);
}
}
void
GeckoStyleContext::SwapStyleData(GeckoStyleContext* aNewContext, uint32_t aStructs)
{
static_assert(nsStyleStructID_Length <= 32, "aStructs is not big enough");
for (nsStyleStructID i = nsStyleStructID_Inherited_Start;
i < nsStyleStructID_Inherited_Start + nsStyleStructID_Inherited_Count;
i = nsStyleStructID(i + 1)) {
uint32_t bit = nsCachedStyleData::GetBitForSID(i);
if (!(aStructs & bit)) {
continue;
}
void*& thisData = mCachedInheritedData.mStyleStructs[i];
void*& otherData = aNewContext->mCachedInheritedData.mStyleStructs[i];
if (mBits & bit) {
if (thisData == otherData) {
thisData = nullptr;
}
} else if (!(aNewContext->mBits & bit) && thisData && otherData) {
std::swap(thisData, otherData);
}
}
for (nsStyleStructID i = nsStyleStructID_Reset_Start;
i < nsStyleStructID_Reset_Start + nsStyleStructID_Reset_Count;
i = nsStyleStructID(i + 1)) {
uint32_t bit = nsCachedStyleData::GetBitForSID(i);
if (!(aStructs & bit)) {
continue;
}
if (!mCachedResetData) {
mCachedResetData = new (PresContext()) nsResetStyleData;
}
if (!aNewContext->mCachedResetData) {
aNewContext->mCachedResetData = new (PresContext()) nsResetStyleData;
}
void*& thisData = mCachedResetData->mStyleStructs[i];
void*& otherData = aNewContext->mCachedResetData->mStyleStructs[i];
if (mBits & bit) {
if (thisData == otherData) {
thisData = nullptr;
}
} else if (!(aNewContext->mBits & bit) && thisData && otherData) {
std::swap(thisData, otherData);
}
}
}
void
GeckoStyleContext::SetStyleIfVisited(already_AddRefed<GeckoStyleContext> aStyleIfVisited)
{
MOZ_ASSERT(!IsStyleIfVisited(), "this context is not visited data");
NS_ASSERTION(!mStyleIfVisited, "should only be set once");
mStyleIfVisited = aStyleIfVisited;
MOZ_ASSERT(mStyleIfVisited->IsStyleIfVisited(),
"other context is visited data");
MOZ_ASSERT(!mStyleIfVisited->GetStyleIfVisited(),
"other context does not have visited data");
NS_ASSERTION(GetStyleIfVisited()->GetPseudo() == GetPseudo(),
"pseudo tag mismatch");
if (GetParent() && GetParent()->GetStyleIfVisited()) {
MOZ_ASSERT(GetStyleIfVisited()->GetParent() ==
GetParent()->GetStyleIfVisited() ||
GetStyleIfVisited()->GetParent() ==
GetParent(),
"parent mismatch");
} else {
MOZ_ASSERT(GetStyleIfVisited()->GetParent() ==
GetParent(),
"parent mismatch");
}
}