// This method is somewhat conservative in what it acceptss.
static bool supportsClassDescendantInvalidation(const CSSSelector& selector)
{
bool foundDescendantRelation = false;
bool foundAncestorIdent = false;
bool foundIdent = false;
for (const CSSSelector* component = &selector; component; component = component->tagHistory()) {
// FIXME: We should allow pseudo elements, but we need to change how they hook
// into recalcStyle by moving them to recalcOwnStyle instead of recalcChildStyle.
// FIXME: next up: Tag and Id.
if (component->m_match == CSSSelector::Class) {
if (!foundDescendantRelation)
foundIdent = true;
else
foundAncestorIdent = true;
} else if (!isSkippableComponentForInvalidation(*component)) {
return false;
}
// FIXME: We can probably support ChildTree and DescendantTree.
switch (component->relation()) {
case CSSSelector::Descendant:
case CSSSelector::Child:
foundDescendantRelation = true;
// Fall through!
case CSSSelector::SubSelector:
continue;
default:
return false;
}
}
return foundDescendantRelation && foundAncestorIdent && foundIdent;
}
// This method is somewhat conservative in what it accepts.
RuleFeatureSet::InvalidationSetMode RuleFeatureSet::invalidationSetModeForSelector(const CSSSelector& selector)
{
bool foundDescendantRelation = false;
bool foundIdent = false;
for (const CSSSelector* component = &selector; component; component = component->tagHistory()) {
if (component->m_match == CSSSelector::Class || component->m_match == CSSSelector::Id
|| (component->m_match == CSSSelector::Tag && component->tagQName().localName() != starAtom)
|| component->isAttributeSelector() || component->isCustomPseudoElement()) {
if (!foundDescendantRelation)
foundIdent = true;
} else if (component->pseudoType() == CSSSelector::PseudoHost || component->pseudoType() == CSSSelector::PseudoAny) {
if (const CSSSelectorList* selectorList = component->selectorList()) {
for (const CSSSelector* selector = selectorList->first(); selector; selector = CSSSelectorList::next(*selector)) {
InvalidationSetMode hostMode = invalidationSetModeForSelector(*selector);
if (hostMode == UseSubtreeStyleChange)
return foundDescendantRelation ? UseLocalStyleChange : UseSubtreeStyleChange;
if (!foundDescendantRelation && hostMode == AddFeatures)
foundIdent = true;
}
}
} else if (!isSkippableComponentForInvalidation(*component)) {
return foundDescendantRelation ? UseLocalStyleChange : UseSubtreeStyleChange;
}
switch (component->relation()) {
case CSSSelector::Descendant:
case CSSSelector::Child:
case CSSSelector::ShadowPseudo:
case CSSSelector::ShadowDeep:
foundDescendantRelation = true;
// Fall through!
case CSSSelector::SubSelector:
case CSSSelector::DirectAdjacent:
case CSSSelector::IndirectAdjacent:
continue;
default:
// All combinators should be handled above.
ASSERT_NOT_REACHED();
return UseLocalStyleChange;
}
}
return foundIdent ? AddFeatures : UseLocalStyleChange;
}
