Magic-Mirror/gecko-dev
1
0
Fork 0
mirror of https://github.com/mozilla/gecko-dev.git synced 2024-12-02 10:00:54 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity
cd02e570d5
gecko-dev/layout/style/nsStyleContext.cpp
Cameron McCormack a60c564803 Bug 931668 - Part 22: Clear cached structs on descendants of an old style context that had structs swapped, if it is staying around. r=dbaron 
--HG--
extra : rebase_source : aa23c06a20214c72d971ab059ef4833846c769fb
2014-09-05 13:48:47 +10:00

1152 lines
42 KiB
C++
Raw Blame History

/* -*- 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/. */
/* the interface (to internal code) for retrieving computed style data */
#include "mozilla/DebugOnly.h"
#include "nsCSSAnonBoxes.h"
#include "nsStyleConsts.h"
#include "nsString.h"
#include "nsPresContext.h"
#include "nsIStyleRule.h"
#include "nsCOMPtr.h"
#include "nsStyleSet.h"
#include "nsIPresShell.h"
#include "nsRuleNode.h"
#include "nsStyleContext.h"
#include "mozilla/StyleAnimationValue.h"
#include "GeckoProfiler.h"
#include "nsIDocument.h"
#ifdef DEBUG
// #define NOISY_DEBUG
#endif
using namespace mozilla;
//----------------------------------------------------------------------
nsStyleContext::nsStyleContext(nsStyleContext* aParent,
nsIAtom* aPseudoTag,
nsCSSPseudoElements::Type aPseudoType,
nsRuleNode* aRuleNode,
bool aSkipParentDisplayBasedStyleFixup)
: mParent(aParent),
mChild(nullptr),
mEmptyChild(nullptr),
mPseudoTag(aPseudoTag),
mRuleNode(aRuleNode),
mCachedResetData(nullptr),
mBits(((uint64_t)aPseudoType) << NS_STYLE_CONTEXT_TYPE_SHIFT),
mRefCnt(0)
{
// This check has to be done "backward", because if it were written the
// more natural way it wouldn't fail even when it needed to.
static_assert((UINT64_MAX >> NS_STYLE_CONTEXT_TYPE_SHIFT) >=
nsCSSPseudoElements::ePseudo_MAX,
"pseudo element bits no longer fit in a uint64_t");
MOZ_ASSERT(aRuleNode);
mNextSibling = this;
mPrevSibling = this;
if (mParent) {
mParent->AddRef();
mParent->AddChild(this);
#ifdef DEBUG
nsRuleNode *r1 = mParent->RuleNode(), *r2 = aRuleNode;
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
}
mRuleNode->AddRef();
mRuleNode->SetUsedDirectly(); // before ApplyStyleFixups()!
ApplyStyleFixups(aSkipParentDisplayBasedStyleFixup);
#define eStyleStruct_LastItem (nsStyleStructID_Length - 1)
NS_ASSERTION(NS_STYLE_INHERIT_MASK & NS_STYLE_INHERIT_BIT(LastItem),
"NS_STYLE_INHERIT_MASK must be bigger, and other bits shifted");
#undef eStyleStruct_LastItem
}
nsStyleContext::~nsStyleContext()
{
NS_ASSERTION((nullptr == mChild) && (nullptr == mEmptyChild), "destructing context with children");
nsPresContext *presContext = mRuleNode->PresContext();
#ifdef DEBUG
#if 0
// 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 even #ifdef DEBUG.
nsStyleContext* root = this;
while (root->mParent) {
root = root->mParent;
}
root->AssertStructsNotUsedElsewhere(this,
std::numeric_limits<int32_t>::max());
#else
// In DEBUG builds we perform a more limited check just of the children
// of this style context.
AssertStructsNotUsedElsewhere(this, 2);
#endif
#endif
mRuleNode->Release();
presContext->PresShell()->StyleSet()->
NotifyStyleContextDestroyed(presContext, this);
if (mParent) {
mParent->RemoveChild(this);
mParent->Release();
}
// Free up our data structs.
mCachedInheritedData.DestroyStructs(mBits, presContext);
if (mCachedResetData) {
mCachedResetData->Destroy(mBits, presContext);
}
}
#ifdef DEBUG
void
nsStyleContext::AssertStructsNotUsedElsewhere(
nsStyleContext* 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("style struct %p found on style context %p\n", data, this); \
nsString url; \
PresContext()->Document()->GetURL(url); \
printf(" in %s\n", NS_LossyConvertUTF16toASCII(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("style struct %p found on style context %p\n", data, this); \
nsString url; \
PresContext()->Document()->GetURL(url); \
printf(" in %s\n", NS_LossyConvertUTF16toASCII(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 nsStyleContext* child = mChild;
do {
child->AssertStructsNotUsedElsewhere(aDestroyingContext, aLevels - 1);
child = child->mNextSibling;
} while (child != mChild);
}
if (mEmptyChild) {
const nsStyleContext* child = mEmptyChild;
do {
child->AssertStructsNotUsedElsewhere(aDestroyingContext, aLevels - 1);
child = child->mNextSibling;
} while (child != mEmptyChild);
}
}
#endif
void nsStyleContext::AddChild(nsStyleContext* aChild)
{
NS_ASSERTION(aChild->mPrevSibling == aChild &&
aChild->mNextSibling == aChild,
"child already in a child list");
nsStyleContext **listPtr = aChild->mRuleNode->IsRoot() ? &mEmptyChild : &mChild;
// Explicitly dereference listPtr so that compiler doesn't have to know that mNextSibling
// etc. don't alias with what ever listPtr points at.
nsStyleContext *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 nsStyleContext::RemoveChild(nsStyleContext* aChild)
{
NS_PRECONDITION(nullptr != aChild && this == aChild->mParent, "bad argument");
nsStyleContext **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;
}
void
nsStyleContext::MoveTo(nsStyleContext* aNewParent)
{
MOZ_ASSERT(aNewParent != mParent);
// 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(!aNewParent->IsStyleIfVisited());
nsStyleContext* oldParent = mParent;
aNewParent->AddRef();
mParent->RemoveChild(this);
mParent = aNewParent;
mParent->AddChild(this);
oldParent->Release();
}
already_AddRefed<nsStyleContext>
nsStyleContext::FindChildWithRules(const nsIAtom* aPseudoTag,
nsRuleNode* aRuleNode,
nsRuleNode* aRulesIfVisited,
bool aRelevantLinkVisited)
{
NS_ABORT_IF_FALSE(aRulesIfVisited || !aRelevantLinkVisited,
"aRelevantLinkVisited should only be set when we have a separate style");
uint32_t threshold = 10; // The # of siblings we're willing to examine
// before just giving this whole thing up.
nsRefPtr<nsStyleContext> result;
nsStyleContext *list = aRuleNode->IsRoot() ? mEmptyChild : mChild;
if (list) {
nsStyleContext *child = list;
do {
if (child->mRuleNode == aRuleNode &&
child->mPseudoTag == aPseudoTag &&
!child->IsStyleIfVisited() &&
child->RelevantLinkVisited() == aRelevantLinkVisited) {
bool match = false;
if (aRulesIfVisited) {
match = child->GetStyleIfVisited() &&
child->GetStyleIfVisited()->mRuleNode == aRulesIfVisited;
} else {
match = !child->GetStyleIfVisited();
}
if (match) {
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();
}
/* static */ bool
nsStyleContext::ListContainsStyleContextThatUsesGrandancestorStyle(const nsStyleContext* aHead)
{
if (aHead) {
const nsStyleContext* child = aHead;
do {
if (child->UsesGrandancestorStyle()) {
return true;
}
child = child->mNextSibling;
} while (child != aHead);
}
return false;
}
bool
nsStyleContext::HasChildThatUsesGrandancestorStyle() const
{
return ListContainsStyleContextThatUsesGrandancestorStyle(mEmptyChild) ||
ListContainsStyleContextThatUsesGrandancestorStyle(mChild);
}
const void* nsStyleContext::GetCachedStyleData(nsStyleStructID aSID)
{
const void* cachedData;
if (nsCachedStyleData::IsReset(aSID)) {
if (mCachedResetData) {
cachedData = mCachedResetData->mStyleStructs[aSID];
} else {
cachedData = nullptr;
}
} else {
cachedData = mCachedInheritedData.mStyleStructs[aSID];
}
return cachedData;
}
const void* nsStyleContext::StyleData(nsStyleStructID aSID)
{
const void* cachedData = GetCachedStyleData(aSID);
if (cachedData)
return cachedData; // We have computed data stored on this node in the context tree.
return mRuleNode->GetStyleData(aSID, this, true); // Our rule node will take care of it for us.
}
// 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*
nsStyleContext::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(Display)
UNIQUE_CASE(Background)
UNIQUE_CASE(Text)
UNIQUE_CASE(TextReset)
#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;
}
void
nsStyleContext::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 (mRuleNode->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;
}
void
nsStyleContext::ApplyStyleFixups(bool aSkipParentDisplayBasedStyleFixup)
{
// 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()) {
mBits |= NS_STYLE_HAS_TEXT_DECORATION_LINES;
} else {
// We might have defined a decoration.
const nsStyleTextReset* text = StyleTextReset();
uint8_t decorationLine = text->mTextDecorationLine;
if (decorationLine != NS_STYLE_TEXT_DECORATION_LINE_NONE &&
decorationLine != NS_STYLE_TEXT_DECORATION_LINE_OVERRIDE_ALL) {
mBits |= NS_STYLE_HAS_TEXT_DECORATION_LINES;
}
}
if ((mParent && mParent->HasPseudoElementData()) || mPseudoTag) {
mBits |= NS_STYLE_HAS_PSEUDO_ELEMENT_DATA;
}
// Correct tables.
const nsStyleDisplay* disp = StyleDisplay();
if (disp->mDisplay == NS_STYLE_DISPLAY_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_CENTER ||
text->mTextAlign == NS_STYLE_TEXT_ALIGN_MOZ_RIGHT)
{
nsStyleText* uniqueText = (nsStyleText*)GetUniqueStyleData(eStyleStruct_Text);
uniqueText->mTextAlign = NS_STYLE_TEXT_ALIGN_DEFAULT;
}
}
// 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) {
uint8_t displayVal = disp->mDisplay;
nsRuleNode::EnsureBlockDisplay(displayVal, true);
if (displayVal != disp->mDisplay) {
nsStyleDisplay *mutable_display =
static_cast<nsStyleDisplay*>(GetUniqueStyleData(eStyleStruct_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,
// placeholders, or table-parts). 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 direct children of elements with Ruby display values which are
// block-level are converted to their inline-level equivalents.
if (!aSkipParentDisplayBasedStyleFixup && mParent) {
const nsStyleDisplay* parentDisp = mParent->StyleDisplay();
if (parentDisp->IsFlexOrGridDisplayType() &&
GetPseudo() != nsCSSAnonBoxes::mozNonElement) {
uint8_t displayVal = disp->mDisplay;
// Skip table parts.
// NOTE: This list needs to be kept in sync with
// nsCSSFrameConstructor.cpp's "sDisplayData" array -- specifically,
// this should be the list of display-values that have
// FCDATA_DESIRED_PARENT_TYPE_TO_BITS specified in that array.
if (NS_STYLE_DISPLAY_TABLE_CAPTION != displayVal &&
NS_STYLE_DISPLAY_TABLE_ROW_GROUP != displayVal &&
NS_STYLE_DISPLAY_TABLE_HEADER_GROUP != displayVal &&
NS_STYLE_DISPLAY_TABLE_FOOTER_GROUP != displayVal &&
NS_STYLE_DISPLAY_TABLE_COLUMN_GROUP != displayVal &&
NS_STYLE_DISPLAY_TABLE_COLUMN != displayVal &&
NS_STYLE_DISPLAY_TABLE_ROW != displayVal &&
NS_STYLE_DISPLAY_TABLE_CELL != displayVal) {
// 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.
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 =
static_cast<nsStyleDisplay*>(GetUniqueStyleData(eStyleStruct_Display));
mutable_display->mDisplay = displayVal;
}
}
} else if (parentDisp->IsRubyDisplayType()) {
uint8_t displayVal = disp->mDisplay;
nsRuleNode::EnsureInlineDisplay(displayVal);
// The display change should only occur for "in-flow" children
if (displayVal != disp->mDisplay &&
!disp->IsOutOfFlowStyle()) {
nsStyleDisplay *mutable_display =
static_cast<nsStyleDisplay*>(GetUniqueStyleData(eStyleStruct_Display));
mutable_display->mDisplay = displayVal;
}
}
}
// Compute User Interface style, to trigger loads of cursors
StyleUserInterface();
}
nsChangeHint
nsStyleContext::CalcStyleDifference(nsStyleContext* aOther,
nsChangeHint aParentHintsNotHandledForDescendants,
uint32_t* aEqualStructs)
{
PROFILER_LABEL("nsStyleContext", "CalcStyleDifference",
js::ProfileEntry::Category::CSS);
NS_ABORT_IF_FALSE(NS_IsHintSubset(aParentHintsNotHandledForDescendants,
nsChangeHint_Hints_NotHandledForDescendants),
"caller is passing inherited hints, but shouldn't be");
static_assert(nsStyleStructID_Length <= 32,
"aEqualStructs is not big enough");
*aEqualStructs = 0;
nsChangeHint hint = NS_STYLE_HINT_NONE;
NS_ENSURE_TRUE(aOther, hint);
// We must always ensure that we populate the structs on the new style
// context that are filled in on the old context, so that if we get
// two style changes in succession, the second of which causes a real
// style change, the PeekStyleData doesn't return null (implying that
// nobody ever looked at that struct's data). In other words, we
// can't skip later structs if we get a big change up front, because
// we could later get a small change in one of those structs that we
// don't want to miss.
// If our rule nodes are the same, then any differences in style data
// are already accounted for by differences on ancestors. We know
// this because CalcStyleDifference is always called on two style
// contexts that point to the same element, so we know that our
// position in the style context tree is the same and our position in
// the rule node tree is also the same.
// However, if there were noninherited style change hints on the
// parent, we might produce these same noninherited hints on this
// style context's frame due to 'inherit' values, so we do need to
// compare.
// (Things like 'em' units are handled by the change hint produced
// by font-size changing, so we don't need to worry about them like
// we worry about 'inherit' values.)
bool compare = mRuleNode != aOther->mRuleNode;
// If we had any change in variable values, then we'll need to examine
// all of the other style structs too, even if the new style context has
// the same rule node as the old one.
const nsStyleVariables* thisVariables = PeekStyleVariables();
if (thisVariables) {
const nsStyleVariables* otherVariables = aOther->StyleVariables();
if (thisVariables->mVariables == otherVariables->mVariables) {
*aEqualStructs |= nsCachedStyleData::GetBitForSID(eStyleStruct_Variables);
} else {
compare = true;
}
} else {
*aEqualStructs |= nsCachedStyleData::GetBitForSID(eStyleStruct_Variables);
}
DebugOnly<int> styleStructCount = 1; // count Variables already
#define DO_STRUCT_DIFFERENCE(struct_) \
PR_BEGIN_MACRO \
const nsStyle##struct_* this##struct_ = PeekStyle##struct_(); \
if (this##struct_) { \
const nsStyle##struct_* other##struct_ = aOther->Style##struct_(); \
nsChangeHint maxDifference = nsStyle##struct_::MaxDifference(); \
nsChangeHint maxDifferenceNeverInherited = \
nsStyle##struct_::MaxDifferenceNeverInherited(); \
if (this##struct_ == other##struct_) { \
/* The very same struct, so we know that there will be no */ \
/* differences. */ \
*aEqualStructs |= NS_STYLE_INHERIT_BIT(struct_); \
} else if (compare || \
(NS_SubtractHint(maxDifference, \
maxDifferenceNeverInherited) & \
aParentHintsNotHandledForDescendants)) { \
nsChangeHint difference = \
this##struct_->CalcDifference(*other##struct_); \
NS_ASSERTION(NS_IsHintSubset(difference, maxDifference), \
"CalcDifference() returned bigger hint than " \
"MaxDifference()"); \
NS_UpdateHint(hint, difference); \
if (!difference) { \
*aEqualStructs |= NS_STYLE_INHERIT_BIT(struct_); \
} \
} else { \
/* We still must call CalcDifference to see if there were any */ \
/* changes so that we can set *aEqualStructs appropriately. */ \
nsChangeHint difference = \
this##struct_->CalcDifference(*other##struct_); \
NS_ASSERTION(NS_IsHintSubset(difference, maxDifference), \
"CalcDifference() returned bigger hint than " \
"MaxDifference()"); \
if (!difference) { \
*aEqualStructs |= NS_STYLE_INHERIT_BIT(struct_); \
} \
} \
} else { \
*aEqualStructs |= NS_STYLE_INHERIT_BIT(struct_); \
} \
styleStructCount++; \
PR_END_MACRO
// In general, we want to examine structs starting with those that can
// cause the largest style change, down to those that can cause the
// smallest. This lets us skip later ones if we already have a hint
// that subsumes their MaxDifference. (As the hints get
// finer-grained, this optimization is becoming less useful, though.)
DO_STRUCT_DIFFERENCE(Display);
DO_STRUCT_DIFFERENCE(XUL);
DO_STRUCT_DIFFERENCE(Column);
DO_STRUCT_DIFFERENCE(Content);
DO_STRUCT_DIFFERENCE(UserInterface);
DO_STRUCT_DIFFERENCE(Visibility);
DO_STRUCT_DIFFERENCE(Outline);
DO_STRUCT_DIFFERENCE(TableBorder);
DO_STRUCT_DIFFERENCE(Table);
DO_STRUCT_DIFFERENCE(UIReset);
DO_STRUCT_DIFFERENCE(Text);
DO_STRUCT_DIFFERENCE(List);
DO_STRUCT_DIFFERENCE(Quotes);
DO_STRUCT_DIFFERENCE(SVGReset);
DO_STRUCT_DIFFERENCE(SVG);
DO_STRUCT_DIFFERENCE(Position);
DO_STRUCT_DIFFERENCE(Font);
DO_STRUCT_DIFFERENCE(Margin);
DO_STRUCT_DIFFERENCE(Padding);
DO_STRUCT_DIFFERENCE(Border);
DO_STRUCT_DIFFERENCE(TextReset);
DO_STRUCT_DIFFERENCE(Background);
DO_STRUCT_DIFFERENCE(Color);
#undef DO_STRUCT_DIFFERENCE
MOZ_ASSERT(styleStructCount == nsStyleStructID_Length,
"missing a call to DO_STRUCT_DIFFERENCE");
// Note that we do not check whether this->RelevantLinkVisited() !=
// aOther->RelevantLinkVisited(); we don't need to since
// nsCSSFrameConstructor::DoContentStateChanged always adds
// nsChangeHint_RepaintFrame for NS_EVENT_STATE_VISITED changes (and
// needs to, since HasStateDependentStyle probably doesn't work right
// for NS_EVENT_STATE_VISITED). Hopefully this doesn't actually
// expose whether links are visited to performance tests since all
// link coloring happens asynchronously at a time when it's hard for
// the page to measure.
// However, we do need to compute the larger of the changes that can
// happen depending on whether the link is visited or unvisited, since
// doing only the one that's currently appropriate would expose which
// links are in history to easy performance measurement. Therefore,
// here, we add nsChangeHint_RepaintFrame hints (the maximum for
// things that can depend on :visited) for the properties on which we
// call GetVisitedDependentColor.
nsStyleContext *thisVis = GetStyleIfVisited(),
*otherVis = aOther->GetStyleIfVisited();
if (!thisVis != !otherVis) {
// One style context has a style-if-visited and the other doesn't.
// Presume a difference.
NS_UpdateHint(hint, nsChangeHint_RepaintFrame);
} else if (thisVis && !NS_IsHintSubset(nsChangeHint_RepaintFrame, hint)) {
// Both style contexts have a style-if-visited.
bool change = false;
// NB: Calling Peek on |this|, not |thisVis|, since callers may look
// at a struct on |this| without looking at the same struct on
// |thisVis| (including this function if we skip one of these checks
// due to change being true already or due to the old style context
// not having a style-if-visited), but not the other way around.
if (PeekStyleColor()) {
if (thisVis->StyleColor()->mColor !=
otherVis->StyleColor()->mColor) {
change = true;
}
}
// NB: Calling Peek on |this|, not |thisVis| (see above).
if (!change && PeekStyleBackground()) {
if (thisVis->StyleBackground()->mBackgroundColor !=
otherVis->StyleBackground()->mBackgroundColor) {
change = true;
}
}
// NB: Calling Peek on |this|, not |thisVis| (see above).
if (!change && PeekStyleBorder()) {
const nsStyleBorder *thisVisBorder = thisVis->StyleBorder();
const nsStyleBorder *otherVisBorder = otherVis->StyleBorder();
NS_FOR_CSS_SIDES(side) {
bool thisFG, otherFG;
nscolor thisColor, otherColor;
thisVisBorder->GetBorderColor(side, thisColor, thisFG);
otherVisBorder->GetBorderColor(side, otherColor, otherFG);
if (thisFG != otherFG || (!thisFG && thisColor != otherColor)) {
change = true;
break;
}
}
}
// NB: Calling Peek on |this|, not |thisVis| (see above).
if (!change && PeekStyleOutline()) {
const nsStyleOutline *thisVisOutline = thisVis->StyleOutline();
const nsStyleOutline *otherVisOutline = otherVis->StyleOutline();
bool haveColor;
nscolor thisColor, otherColor;
if (thisVisOutline->GetOutlineInitialColor() !=
otherVisOutline->GetOutlineInitialColor() ||
(haveColor = thisVisOutline->GetOutlineColor(thisColor)) !=
otherVisOutline->GetOutlineColor(otherColor) ||
(haveColor && thisColor != otherColor)) {
change = true;
}
}
// NB: Calling Peek on |this|, not |thisVis| (see above).
if (!change && PeekStyleColumn()) {
const nsStyleColumn *thisVisColumn = thisVis->StyleColumn();
const nsStyleColumn *otherVisColumn = otherVis->StyleColumn();
if (thisVisColumn->mColumnRuleColor != otherVisColumn->mColumnRuleColor ||
thisVisColumn->mColumnRuleColorIsForeground !=
otherVisColumn->mColumnRuleColorIsForeground) {
change = true;
}
}
// NB: Calling Peek on |this|, not |thisVis| (see above).
if (!change && PeekStyleTextReset()) {
const nsStyleTextReset *thisVisTextReset = thisVis->StyleTextReset();
const nsStyleTextReset *otherVisTextReset = otherVis->StyleTextReset();
nscolor thisVisDecColor, otherVisDecColor;
bool thisVisDecColorIsFG, otherVisDecColorIsFG;
thisVisTextReset->GetDecorationColor(thisVisDecColor,
thisVisDecColorIsFG);
otherVisTextReset->GetDecorationColor(otherVisDecColor,
otherVisDecColorIsFG);
if (thisVisDecColorIsFG != otherVisDecColorIsFG ||
(!thisVisDecColorIsFG && thisVisDecColor != otherVisDecColor)) {
change = true;
}
}
// NB: Calling Peek on |this|, not |thisVis| (see above).
if (!change && PeekStyleSVG()) {
const nsStyleSVG *thisVisSVG = thisVis->StyleSVG();
const nsStyleSVG *otherVisSVG = otherVis->StyleSVG();
if (thisVisSVG->mFill != otherVisSVG->mFill ||
thisVisSVG->mStroke != otherVisSVG->mStroke) {
change = true;
}
}
if (change) {
NS_UpdateHint(hint, nsChangeHint_RepaintFrame);
}
}
return NS_SubtractHint(hint, nsChangeHint_NeutralChange);
}
void
nsStyleContext::Mark()
{
// Mark our rule node.
mRuleNode->Mark();
// Mark our children (i.e., tell them to mark their rule nodes, etc.).
if (mChild) {
nsStyleContext* child = mChild;
do {
child->Mark();
child = child->mNextSibling;
} while (mChild != child);
}
if (mEmptyChild) {
nsStyleContext* child = mEmptyChild;
do {
child->Mark();
child = child->mNextSibling;
} while (mEmptyChild != child);
}
}
#ifdef DEBUG
void nsStyleContext::List(FILE* out, int32_t aIndent)
{
// Indent
int32_t ix;
for (ix = aIndent; --ix >= 0; ) fputs(" ", out);
fprintf(out, "%p(%d) parent=%p ",
(void*)this, mRefCnt, (void *)mParent);
if (mPseudoTag) {
nsAutoString buffer;
mPseudoTag->ToString(buffer);
fputs(NS_LossyConvertUTF16toASCII(buffer).get(), out);
fputs(" ", out);
}
if (mRuleNode) {
fputs("{\n", out);
nsRuleNode* ruleNode = mRuleNode;
while (ruleNode) {
nsIStyleRule *styleRule = ruleNode->GetRule();
if (styleRule) {
styleRule->List(out, aIndent + 1);
}
ruleNode = ruleNode->GetParent();
}
for (ix = aIndent; --ix >= 0; ) fputs(" ", out);
fputs("}\n", out);
}
else {
fputs("{}\n", out);
}
if (nullptr != mChild) {
nsStyleContext* child = mChild;
do {
child->List(out, aIndent + 1);
child = child->mNextSibling;
} while (mChild != child);
}
if (nullptr != mEmptyChild) {
nsStyleContext* child = mEmptyChild;
do {
child->List(out, aIndent + 1);
child = child->mNextSibling;
} while (mEmptyChild != child);
}
}
#endif
// Overloaded new operator. Initializes the memory to 0 and relies on an arena
// (which comes from the presShell) to perform the allocation.
void*
nsStyleContext::operator new(size_t sz, nsPresContext* aPresContext) CPP_THROW_NEW
{
// Check the recycle list first.
return aPresContext->PresShell()->AllocateByObjectID(nsPresArena::nsStyleContext_id, 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
nsStyleContext::Destroy()
{
// Get the pres context from our rule node.
nsRefPtr<nsPresContext> presContext = mRuleNode->PresContext();
// Call our destructor.
this->~nsStyleContext();
// Don't let the memory be freed, since it will be recycled
// instead. Don't call the global operator delete.
presContext->PresShell()->FreeByObjectID(nsPresArena::nsStyleContext_id, this);
}
already_AddRefed<nsStyleContext>
NS_NewStyleContext(nsStyleContext* aParentContext,
nsIAtom* aPseudoTag,
nsCSSPseudoElements::Type aPseudoType,
nsRuleNode* aRuleNode,
bool aSkipParentDisplayBasedStyleFixup)
{
nsRefPtr<nsStyleContext> context =
new (aRuleNode->PresContext())
nsStyleContext(aParentContext, aPseudoTag, aPseudoType, aRuleNode,
aSkipParentDisplayBasedStyleFixup);
return context.forget();
}
static inline void
ExtractAnimationValue(nsCSSProperty aProperty,
nsStyleContext* aStyleContext,
StyleAnimationValue& aResult)
{
DebugOnly<bool> success =
StyleAnimationValue::ExtractComputedValue(aProperty, aStyleContext,
aResult);
NS_ABORT_IF_FALSE(success,
"aProperty must be extractable by StyleAnimationValue");
}
static nscolor
ExtractColor(nsCSSProperty aProperty,
nsStyleContext *aStyleContext)
{
StyleAnimationValue val;
ExtractAnimationValue(aProperty, aStyleContext, val);
return val.GetColorValue();
}
static nscolor
ExtractColorLenient(nsCSSProperty aProperty,
nsStyleContext *aStyleContext)
{
StyleAnimationValue val;
ExtractAnimationValue(aProperty, aStyleContext, val);
if (val.GetUnit() == StyleAnimationValue::eUnit_Color) {
return val.GetColorValue();
}
return NS_RGBA(0, 0, 0, 0);
}
struct ColorIndexSet {
uint8_t colorIndex, alphaIndex;
};
static const ColorIndexSet gVisitedIndices[2] = { { 0, 0 }, { 1, 0 } };
nscolor
nsStyleContext::GetVisitedDependentColor(nsCSSProperty aProperty)
{
NS_ASSERTION(aProperty == eCSSProperty_color ||
aProperty == eCSSProperty_background_color ||
aProperty == eCSSProperty_border_top_color ||
aProperty == eCSSProperty_border_right_color_value ||
aProperty == eCSSProperty_border_bottom_color ||
aProperty == eCSSProperty_border_left_color_value ||
aProperty == eCSSProperty_outline_color ||
aProperty == eCSSProperty__moz_column_rule_color ||
aProperty == eCSSProperty_text_decoration_color ||
aProperty == eCSSProperty_fill ||
aProperty == eCSSProperty_stroke,
"we need to add to nsStyleContext::CalcStyleDifference");
bool isPaintProperty = aProperty == eCSSProperty_fill ||
aProperty == eCSSProperty_stroke;
nscolor colors[2];
colors[0] = isPaintProperty ? ExtractColorLenient(aProperty, this)
: ExtractColor(aProperty, this);
nsStyleContext *visitedStyle = this->GetStyleIfVisited();
if (!visitedStyle) {
return colors[0];
}
colors[1] = isPaintProperty ? ExtractColorLenient(aProperty, visitedStyle)
: ExtractColor(aProperty, visitedStyle);
return nsStyleContext::CombineVisitedColors(colors,
this->RelevantLinkVisited());
}
/* static */ nscolor
nsStyleContext::CombineVisitedColors(nscolor *aColors, bool aLinkIsVisited)
{
if (NS_GET_A(aColors[1]) == 0) {
// If the style-if-visited is transparent, then just use the
// unvisited style rather than using the (meaningless) color
// components of the visited style along with a potentially
// non-transparent alpha value.
aLinkIsVisited = false;
}
// NOTE: We want this code to have as little timing dependence as
// possible on whether this->RelevantLinkVisited() is true.
const ColorIndexSet &set =
gVisitedIndices[aLinkIsVisited ? 1 : 0];
nscolor colorColor = aColors[set.colorIndex];
nscolor alphaColor = aColors[set.alphaIndex];
return NS_RGBA(NS_GET_R(colorColor), NS_GET_G(colorColor),
NS_GET_B(colorColor), NS_GET_A(alphaColor));
}
#ifdef DEBUG
/* static */ void
nsStyleContext::AssertStyleStructMaxDifferenceValid()
{
#define STYLE_STRUCT(name, checkdata_cb) \
MOZ_ASSERT(NS_IsHintSubset(nsStyle##name::MaxDifferenceNeverInherited(), \
nsStyle##name::MaxDifference()));
#include "nsStyleStructList.h"
#undef STYLE_STRUCT
}
#endif
bool
nsStyleContext::HasSameCachedStyleData(nsStyleContext* aOther,
nsStyleStructID aSID)
{
return GetCachedStyleData(aSID) == aOther->GetCachedStyleData(aSID);
}
void
nsStyleContext::SwapStyleData(nsStyleContext* 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 (mRuleNode->PresContext()) nsResetStyleData;
}
if (!aNewContext->mCachedResetData) {
aNewContext->mCachedResetData =
new (mRuleNode->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
nsStyleContext::ClearCachedInheritedStyleDataOnDescendants(uint32_t aStructs)
{
if (mChild) {
nsStyleContext* child = mChild;
do {
child->DoClearCachedInheritedStyleDataOnDescendants(aStructs);
child = child->mNextSibling;
} while (mChild != child);
}
if (mEmptyChild) {
nsStyleContext* child = mEmptyChild;
do {
child->DoClearCachedInheritedStyleDataOnDescendants(aStructs);
child = child->mNextSibling;
} while (mEmptyChild != child);
}
}
void
nsStyleContext::DoClearCachedInheritedStyleDataOnDescendants(uint32_t aStructs)
{
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);
}
Reference in New Issue View Git Blame Copy Permalink