gecko-dev/layout/style/nsHTMLStyleSheet.cpp
Nathan Froyd 1c2c21cebc Bug 1295192 - part 4 - use a non-null-checked placement new operator in layout code; r=dholbert
The standard placement new function is declared to not throw, which
means that, per spec, a null check on its result is required.  There are
a number of places throughout layout/ where we know that we are passing
non-null pointers to placement new (and receiving them as a return
value), and we are therefore doing useless work performing these null
checks.

Therefore, we should be using an operator new overload that doesn't
require the null check.  MFBT has just such an overload, so use that.
2016-08-17 15:28:45 -04:00

593 lines
17 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/.
*
* This Original Code has been modified by IBM Corporation. Modifications made by IBM
* described herein are Copyright (c) International Business Machines Corporation, 2000.
* Modifications to Mozilla code or documentation identified per MPL Section 3.3
*
* Date Modified by Description of modification
* 04/20/2000 IBM Corp. OS/2 VisualAge build.
*/
/*
* style sheet and style rule processor representing data from presentational
* HTML attributes
*/
#include "nsHTMLStyleSheet.h"
#include "nsMappedAttributes.h"
#include "nsGkAtoms.h"
#include "nsPresContext.h"
#include "mozilla/EventStates.h"
#include "nsIDocument.h"
#include "nsIPresShell.h"
#include "nsStyleConsts.h"
#include "nsRuleWalker.h"
#include "nsRuleData.h"
#include "nsError.h"
#include "nsRuleProcessorData.h"
#include "nsCSSRuleProcessor.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/dom/Element.h"
#include "nsHashKeys.h"
#include "mozilla/OperatorNewExtensions.h"
#include "mozilla/RestyleManagerHandle.h"
#include "mozilla/RestyleManagerHandleInlines.h"
using namespace mozilla;
using namespace mozilla::dom;
NS_IMPL_ISUPPORTS(nsHTMLStyleSheet::HTMLColorRule, nsIStyleRule)
/* virtual */ void
nsHTMLStyleSheet::HTMLColorRule::MapRuleInfoInto(nsRuleData* aRuleData)
{
if (aRuleData->mSIDs & NS_STYLE_INHERIT_BIT(Color)) {
nsCSSValue* color = aRuleData->ValueForColor();
if (color->GetUnit() == eCSSUnit_Null &&
aRuleData->mPresContext->UseDocumentColors())
color->SetColorValue(mColor);
}
}
/* virtual */ bool
nsHTMLStyleSheet::HTMLColorRule::MightMapInheritedStyleData()
{
return true;
}
/* virtual */ bool
nsHTMLStyleSheet::HTMLColorRule::
GetDiscretelyAnimatedCSSValue(nsCSSPropertyID aProperty, nsCSSValue* aValue)
{
MOZ_ASSERT(false, "GetDiscretelyAnimatedCSSValue is not implemented yet");
return false;
}
#ifdef DEBUG
/* virtual */ void
nsHTMLStyleSheet::HTMLColorRule::List(FILE* out, int32_t aIndent) const
{
nsAutoCString indentStr;
for (int32_t index = aIndent; --index >= 0; ) {
indentStr.AppendLiteral(" ");
}
fprintf_stderr(out, "%s[html color rule] {}\n", indentStr.get());
}
#endif
NS_IMPL_ISUPPORTS(nsHTMLStyleSheet::GenericTableRule, nsIStyleRule)
#ifdef DEBUG
/* virtual */ void
nsHTMLStyleSheet::GenericTableRule::List(FILE* out, int32_t aIndent) const
{
nsAutoCString indentStr;
for (int32_t index = aIndent; --index >= 0; ) {
indentStr.AppendLiteral(" ");
}
fprintf_stderr(out, "%s[generic table rule] {}\n", indentStr.get());
}
#endif
/* virtual */ void
nsHTMLStyleSheet::TableTHRule::MapRuleInfoInto(nsRuleData* aRuleData)
{
if (aRuleData->mSIDs & NS_STYLE_INHERIT_BIT(Text)) {
nsCSSValue* textAlign = aRuleData->ValueForTextAlign();
if (textAlign->GetUnit() == eCSSUnit_Null) {
textAlign->SetIntValue(NS_STYLE_TEXT_ALIGN_MOZ_CENTER_OR_INHERIT,
eCSSUnit_Enumerated);
}
}
}
/* virtual */ bool
nsHTMLStyleSheet::TableTHRule::MightMapInheritedStyleData()
{
return true;
}
/* virtual */ bool
nsHTMLStyleSheet::TableTHRule::
GetDiscretelyAnimatedCSSValue(nsCSSPropertyID aProperty, nsCSSValue* aValue)
{
MOZ_ASSERT(false, "GetDiscretelyAnimatedCSSValue is not implemented yet");
return false;
}
/* virtual */ void
nsHTMLStyleSheet::TableQuirkColorRule::MapRuleInfoInto(nsRuleData* aRuleData)
{
if (aRuleData->mSIDs & NS_STYLE_INHERIT_BIT(Color)) {
nsCSSValue* color = aRuleData->ValueForColor();
// We do not check UseDocumentColors() here, because we want to
// use the body color no matter what.
if (color->GetUnit() == eCSSUnit_Null)
color->SetIntValue(NS_STYLE_COLOR_INHERIT_FROM_BODY,
eCSSUnit_Enumerated);
}
}
/* virtual */ bool
nsHTMLStyleSheet::TableQuirkColorRule::MightMapInheritedStyleData()
{
return true;
}
/* virtual */ bool
nsHTMLStyleSheet::TableQuirkColorRule::
GetDiscretelyAnimatedCSSValue(nsCSSPropertyID aProperty, nsCSSValue* aValue)
{
MOZ_ASSERT(false, "GetDiscretelyAnimatedCSSValue is not implemented yet");
return false;
}
NS_IMPL_ISUPPORTS(nsHTMLStyleSheet::LangRule, nsIStyleRule)
/* virtual */ void
nsHTMLStyleSheet::LangRule::MapRuleInfoInto(nsRuleData* aRuleData)
{
if (aRuleData->mSIDs & NS_STYLE_INHERIT_BIT(Font)) {
nsCSSValue* lang = aRuleData->ValueForLang();
if (lang->GetUnit() == eCSSUnit_Null) {
lang->SetStringValue(mLang, eCSSUnit_Ident);
}
}
}
/* virtual */ bool
nsHTMLStyleSheet::LangRule::MightMapInheritedStyleData()
{
return true;
}
/* virtual */ bool
nsHTMLStyleSheet::LangRule::
GetDiscretelyAnimatedCSSValue(nsCSSPropertyID aProperty, nsCSSValue* aValue)
{
MOZ_ASSERT(false, "GetDiscretelyAnimatedCSSValue is not implemented yet");
return false;
}
#ifdef DEBUG
/* virtual */ void
nsHTMLStyleSheet::LangRule::List(FILE* out, int32_t aIndent) const
{
nsAutoCString str;
for (int32_t index = aIndent; --index >= 0; ) {
str.AppendLiteral(" ");
}
str.AppendLiteral("[lang rule] { language: \"");
AppendUTF16toUTF8(mLang, str);
str.AppendLiteral("\" }\n");
fprintf_stderr(out, "%s", str.get());
}
#endif
// -----------------------------------------------------------
struct MappedAttrTableEntry : public PLDHashEntryHdr {
nsMappedAttributes *mAttributes;
};
static PLDHashNumber
MappedAttrTable_HashKey(const void *key)
{
nsMappedAttributes *attributes =
static_cast<nsMappedAttributes*>(const_cast<void*>(key));
return attributes->HashValue();
}
static void
MappedAttrTable_ClearEntry(PLDHashTable *table, PLDHashEntryHdr *hdr)
{
MappedAttrTableEntry *entry = static_cast<MappedAttrTableEntry*>(hdr);
entry->mAttributes->DropStyleSheetReference();
memset(entry, 0, sizeof(MappedAttrTableEntry));
}
static bool
MappedAttrTable_MatchEntry(const PLDHashEntryHdr *hdr, const void *key)
{
nsMappedAttributes *attributes =
static_cast<nsMappedAttributes*>(const_cast<void*>(key));
const MappedAttrTableEntry *entry =
static_cast<const MappedAttrTableEntry*>(hdr);
return attributes->Equals(entry->mAttributes);
}
static const PLDHashTableOps MappedAttrTable_Ops = {
MappedAttrTable_HashKey,
MappedAttrTable_MatchEntry,
PLDHashTable::MoveEntryStub,
MappedAttrTable_ClearEntry,
nullptr
};
// -----------------------------------------------------------
struct LangRuleTableEntry : public PLDHashEntryHdr {
RefPtr<nsHTMLStyleSheet::LangRule> mRule;
};
static PLDHashNumber
LangRuleTable_HashKey(const void *key)
{
const nsString *lang = static_cast<const nsString*>(key);
return HashString(*lang);
}
static void
LangRuleTable_ClearEntry(PLDHashTable *table, PLDHashEntryHdr *hdr)
{
LangRuleTableEntry *entry = static_cast<LangRuleTableEntry*>(hdr);
entry->~LangRuleTableEntry();
memset(entry, 0, sizeof(LangRuleTableEntry));
}
static bool
LangRuleTable_MatchEntry(const PLDHashEntryHdr *hdr, const void *key)
{
const nsString *lang = static_cast<const nsString*>(key);
const LangRuleTableEntry *entry = static_cast<const LangRuleTableEntry*>(hdr);
return entry->mRule->mLang == *lang;
}
static void
LangRuleTable_InitEntry(PLDHashEntryHdr *hdr, const void *key)
{
const nsString *lang = static_cast<const nsString*>(key);
LangRuleTableEntry *entry = new (KnownNotNull, hdr) LangRuleTableEntry();
// Create the unique rule for this language
entry->mRule = new nsHTMLStyleSheet::LangRule(*lang);
}
static const PLDHashTableOps LangRuleTable_Ops = {
LangRuleTable_HashKey,
LangRuleTable_MatchEntry,
PLDHashTable::MoveEntryStub,
LangRuleTable_ClearEntry,
LangRuleTable_InitEntry
};
// -----------------------------------------------------------
nsHTMLStyleSheet::nsHTMLStyleSheet(nsIDocument* aDocument)
: mDocument(aDocument)
, mTableQuirkColorRule(new TableQuirkColorRule())
, mTableTHRule(new TableTHRule())
, mMappedAttrTable(&MappedAttrTable_Ops, sizeof(MappedAttrTableEntry))
, mLangRuleTable(&LangRuleTable_Ops, sizeof(LangRuleTableEntry))
{
MOZ_ASSERT(aDocument);
}
NS_IMPL_ISUPPORTS(nsHTMLStyleSheet, nsIStyleRuleProcessor)
/* virtual */ void
nsHTMLStyleSheet::RulesMatching(ElementRuleProcessorData* aData)
{
nsRuleWalker *ruleWalker = aData->mRuleWalker;
if (!ruleWalker->AuthorStyleDisabled()) {
// if we have anchor colors, check if this is an anchor with an href
if (aData->mElement->IsHTMLElement(nsGkAtoms::a)) {
if (mLinkRule || mVisitedRule || mActiveRule) {
EventStates state =
nsCSSRuleProcessor::GetContentStateForVisitedHandling(
aData->mElement,
aData->mTreeMatchContext,
aData->mTreeMatchContext.VisitedHandling(),
// If the node being matched is a link,
// it's the relevant link.
nsCSSRuleProcessor::IsLink(aData->mElement));
if (mLinkRule && state.HasState(NS_EVENT_STATE_UNVISITED)) {
ruleWalker->Forward(mLinkRule);
aData->mTreeMatchContext.SetHaveRelevantLink();
}
else if (mVisitedRule && state.HasState(NS_EVENT_STATE_VISITED)) {
ruleWalker->Forward(mVisitedRule);
aData->mTreeMatchContext.SetHaveRelevantLink();
}
// No need to add to the active rule if it's not a link
if (mActiveRule && nsCSSRuleProcessor::IsLink(aData->mElement) &&
state.HasState(NS_EVENT_STATE_ACTIVE)) {
ruleWalker->Forward(mActiveRule);
}
} // end link/visited/active rules
} // end A tag
// add the rule to handle text-align for a <th>
else if (aData->mElement->IsHTMLElement(nsGkAtoms::th)) {
ruleWalker->Forward(mTableTHRule);
}
else if (aData->mElement->IsHTMLElement(nsGkAtoms::table)) {
if (aData->mTreeMatchContext.mCompatMode == eCompatibility_NavQuirks) {
ruleWalker->Forward(mTableQuirkColorRule);
}
}
} // end html element
// just get the style rules from the content. For SVG we do this even if
// author style is disabled, because SVG presentational hints aren't
// considered style.
if (!ruleWalker->AuthorStyleDisabled() || aData->mElement->IsSVGElement()) {
aData->mElement->WalkContentStyleRules(ruleWalker);
}
// http://www.whatwg.org/specs/web-apps/current-work/multipage/elements.html#language
// says that the xml:lang attribute overrides HTML's lang attribute,
// so we need to do this after WalkContentStyleRules.
nsString lang;
if (aData->mElement->GetAttr(kNameSpaceID_XML, nsGkAtoms::lang, lang)) {
ruleWalker->Forward(LangRuleFor(lang));
}
// Set the language to "x-math" on the <math> element, so that appropriate
// font settings are used for MathML.
if (aData->mElement->IsMathMLElement(nsGkAtoms::math)) {
nsGkAtoms::x_math->ToString(lang);
ruleWalker->Forward(LangRuleFor(lang));
}
}
// Test if style is dependent on content state
/* virtual */ nsRestyleHint
nsHTMLStyleSheet::HasStateDependentStyle(StateRuleProcessorData* aData)
{
if (aData->mElement->IsHTMLElement(nsGkAtoms::a) &&
nsCSSRuleProcessor::IsLink(aData->mElement) &&
((mActiveRule && aData->mStateMask.HasState(NS_EVENT_STATE_ACTIVE)) ||
(mLinkRule && aData->mStateMask.HasState(NS_EVENT_STATE_VISITED)) ||
(mVisitedRule && aData->mStateMask.HasState(NS_EVENT_STATE_VISITED)))) {
return eRestyle_Self;
}
return nsRestyleHint(0);
}
/* virtual */ nsRestyleHint
nsHTMLStyleSheet::HasStateDependentStyle(PseudoElementStateRuleProcessorData* aData)
{
return nsRestyleHint(0);
}
/* virtual */ bool
nsHTMLStyleSheet::HasDocumentStateDependentStyle(StateRuleProcessorData* aData)
{
return false;
}
/* virtual */ nsRestyleHint
nsHTMLStyleSheet::HasAttributeDependentStyle(
AttributeRuleProcessorData* aData,
RestyleHintData& aRestyleHintDataResult)
{
// Do nothing on before-change checks
if (!aData->mAttrHasChanged) {
return nsRestyleHint(0);
}
// Note: no need to worry about whether some states changed with this
// attribute here, because we handle that under HasStateDependentStyle() as
// needed.
// Result is true for |href| changes on HTML links if we have link rules.
Element *element = aData->mElement;
if (aData->mAttribute == nsGkAtoms::href &&
(mLinkRule || mVisitedRule || mActiveRule) &&
element->IsHTMLElement(nsGkAtoms::a)) {
return eRestyle_Self;
}
// Don't worry about the mDocumentColorRule since it only applies
// to descendants of body, when we're already reresolving.
// Handle the content style rules.
if (element->IsAttributeMapped(aData->mAttribute)) {
// cellpadding on tables is special and requires reresolving all
// the cells in the table
if (aData->mAttribute == nsGkAtoms::cellpadding &&
element->IsHTMLElement(nsGkAtoms::table)) {
return eRestyle_Subtree;
}
return eRestyle_Self;
}
return nsRestyleHint(0);
}
/* virtual */ bool
nsHTMLStyleSheet::MediumFeaturesChanged(nsPresContext* aPresContext)
{
return false;
}
/* virtual */ size_t
nsHTMLStyleSheet::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
{
return 0; // nsHTMLStyleSheets are charged to the DOM, not layout
}
/* virtual */ size_t
nsHTMLStyleSheet::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const
{
return 0; // nsHTMLStyleSheets are charged to the DOM, not layout
}
/* virtual */ void
nsHTMLStyleSheet::RulesMatching(PseudoElementRuleProcessorData* aData)
{
}
/* virtual */ void
nsHTMLStyleSheet::RulesMatching(AnonBoxRuleProcessorData* aData)
{
}
#ifdef MOZ_XUL
/* virtual */ void
nsHTMLStyleSheet::RulesMatching(XULTreeRuleProcessorData* aData)
{
}
#endif
void
nsHTMLStyleSheet::SetOwningDocument(nsIDocument* aDocument)
{
mDocument = aDocument; // not refcounted
}
void
nsHTMLStyleSheet::Reset()
{
mLinkRule = nullptr;
mVisitedRule = nullptr;
mActiveRule = nullptr;
mLangRuleTable.Clear();
mMappedAttrTable.Clear();
}
nsresult
nsHTMLStyleSheet::ImplLinkColorSetter(RefPtr<HTMLColorRule>& aRule, nscolor aColor)
{
if (aRule && aRule->mColor == aColor) {
return NS_OK;
}
aRule = new HTMLColorRule();
if (!aRule)
return NS_ERROR_OUT_OF_MEMORY;
aRule->mColor = aColor;
// Now make sure we restyle any links that might need it. This
// shouldn't happen often, so just rebuilding everything is ok.
if (mDocument && mDocument->GetShell()) {
Element* root = mDocument->GetRootElement();
if (root) {
mDocument->GetShell()->GetPresContext()->RestyleManager()->
PostRestyleEvent(root, eRestyle_Subtree, nsChangeHint(0));
}
}
return NS_OK;
}
nsresult
nsHTMLStyleSheet::SetLinkColor(nscolor aColor)
{
return ImplLinkColorSetter(mLinkRule, aColor);
}
nsresult
nsHTMLStyleSheet::SetActiveLinkColor(nscolor aColor)
{
return ImplLinkColorSetter(mActiveRule, aColor);
}
nsresult
nsHTMLStyleSheet::SetVisitedLinkColor(nscolor aColor)
{
return ImplLinkColorSetter(mVisitedRule, aColor);
}
already_AddRefed<nsMappedAttributes>
nsHTMLStyleSheet::UniqueMappedAttributes(nsMappedAttributes* aMapped)
{
auto entry = static_cast<MappedAttrTableEntry*>
(mMappedAttrTable.Add(aMapped, fallible));
if (!entry)
return nullptr;
if (!entry->mAttributes) {
// We added a new entry to the hashtable, so we have a new unique set.
entry->mAttributes = aMapped;
}
RefPtr<nsMappedAttributes> ret = entry->mAttributes;
return ret.forget();
}
void
nsHTMLStyleSheet::DropMappedAttributes(nsMappedAttributes* aMapped)
{
NS_ENSURE_TRUE_VOID(aMapped);
#ifdef DEBUG
uint32_t entryCount = mMappedAttrTable.EntryCount() - 1;
#endif
mMappedAttrTable.Remove(aMapped);
NS_ASSERTION(entryCount == mMappedAttrTable.EntryCount(), "not removed");
}
nsIStyleRule*
nsHTMLStyleSheet::LangRuleFor(const nsString& aLanguage)
{
auto entry =
static_cast<LangRuleTableEntry*>(mLangRuleTable.Add(&aLanguage, fallible));
if (!entry) {
NS_ASSERTION(false, "out of memory");
return nullptr;
}
return entry->mRule;
}
size_t
nsHTMLStyleSheet::DOMSizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const
{
size_t n = aMallocSizeOf(this);
n += mMappedAttrTable.ShallowSizeOfExcludingThis(aMallocSizeOf);
for (auto iter = mMappedAttrTable.ConstIter(); !iter.Done(); iter.Next()) {
auto entry = static_cast<MappedAttrTableEntry*>(iter.Get());
n += entry->mAttributes->SizeOfIncludingThis(aMallocSizeOf);
}
// Measurement of the following members may be added later if DMD finds it is
// worthwhile:
// - mURL
// - mLinkRule
// - mVisitedRule
// - mActiveRule
// - mTableQuirkColorRule
// - mTableTHRule
// - mLangRuleTable
//
// The following members are not measured:
// - mDocument, because it's non-owning
return n;
}