StyleInvalidationAnalysis.cpp [plain text]
#include "config.h"
#include "StyleInvalidationAnalysis.h"
#include "CSSSelectorList.h"
#include "Document.h"
#include "ElementIterator.h"
#include "ElementRuleCollector.h"
#include "SelectorFilter.h"
#include "StyleRuleImport.h"
#include "StyleSheetContents.h"
namespace WebCore {
static bool shouldDirtyAllStyle(const Vector<RefPtr<StyleRuleBase>>& rules)
{
for (auto& rule : rules) {
if (is<StyleRuleMedia>(*rule)) {
if (shouldDirtyAllStyle(downcast<StyleRuleMedia>(*rule).childRules()))
return true;
continue;
}
if (!is<StyleRule>(*rule))
return true;
}
return false;
}
static bool shouldDirtyAllStyle(const StyleSheetContents& sheet)
{
for (auto& import : sheet.importRules()) {
if (!import->styleSheet())
continue;
if (shouldDirtyAllStyle(*import->styleSheet()))
return true;
}
if (shouldDirtyAllStyle(sheet.childRules()))
return true;
return false;
}
static bool shouldDirtyAllStyle(const Vector<StyleSheetContents*>& sheets)
{
for (auto& sheet : sheets) {
if (shouldDirtyAllStyle(*sheet))
return true;
}
return false;
}
StyleInvalidationAnalysis::StyleInvalidationAnalysis(const Vector<StyleSheetContents*>& sheets, const MediaQueryEvaluator& mediaQueryEvaluator)
: m_dirtiesAllStyle(shouldDirtyAllStyle(sheets))
{
if (m_dirtiesAllStyle)
return;
m_ruleSets.resetAuthorStyle();
for (auto& sheet : sheets)
m_ruleSets.authorStyle()->addRulesFromSheet(sheet, mediaQueryEvaluator);
if (m_ruleSets.authorStyle()->hasShadowPseudoElementRules())
m_dirtiesAllStyle = true;
}
enum class CheckDescendants { Yes, No };
static CheckDescendants invalidateIfNeeded(Element& element, SelectorFilter& filter, const DocumentRuleSets& ruleSets)
{
switch (element.styleChangeType()) {
case NoStyleChange: {
ElementRuleCollector ruleCollector(element, nullptr, ruleSets, filter);
ruleCollector.setMode(SelectorChecker::Mode::CollectingRulesIgnoringVirtualPseudoElements);
ruleCollector.matchAuthorRules(false);
if (ruleCollector.hasMatchedRules())
element.setNeedsStyleRecalc(InlineStyleChange);
return CheckDescendants::Yes;
}
case InlineStyleChange:
return CheckDescendants::Yes;
case FullStyleChange:
case SyntheticStyleChange:
case ReconstructRenderTree:
return CheckDescendants::No;
}
ASSERT_NOT_REACHED();
return CheckDescendants::Yes;
}
static void invalidateStyleForTree(Element& root, SelectorFilter& filter, const DocumentRuleSets& ruleSets)
{
if (invalidateIfNeeded(root, filter, ruleSets) == CheckDescendants::No)
return;
Vector<Element*, 20> parentStack;
Element* previousElement = &root;
auto descendants = descendantsOfType<Element>(root);
for (auto it = descendants.begin(), end = descendants.end(); it != end;) {
auto& descendant = *it;
auto* parent = descendant.parentElement();
if (parentStack.isEmpty() || parentStack.last() != parent) {
if (parent == previousElement) {
parentStack.append(parent);
filter.pushParent(parent);
} else {
while (parentStack.last() != parent) {
parentStack.removeLast();
filter.popParent();
}
}
}
previousElement = &descendant;
if (invalidateIfNeeded(descendant, filter, ruleSets) == CheckDescendants::Yes)
it.traverseNext();
else
it.traverseNextSkippingChildren();
}
while (!parentStack.isEmpty()) {
parentStack.removeLast();
filter.popParent();
}
}
void StyleInvalidationAnalysis::invalidateStyle(Document& document)
{
ASSERT(!m_dirtiesAllStyle);
if (!m_ruleSets.authorStyle())
return;
Element* documentElement = document.documentElement();
if (!documentElement)
return;
SelectorFilter filter;
filter.setupParentStack(documentElement);
invalidateStyleForTree(*documentElement, filter, m_ruleSets);
}
}