1 files changed, 124 insertions, 0 deletions
diff --git a/Source/WebCore/style/AttributeChangeInvalidation.cpp b/Source/WebCore/style/AttributeChangeInvalidation.cpp
new file mode 100644
index 000000000..f71c6ea05
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+++ b/Source/WebCore/style/AttributeChangeInvalidation.cpp
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+/*
+ * Copyright (C) 2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "AttributeChangeInvalidation.h"
+
+#include "DocumentRuleSets.h"
+#include "ElementIterator.h"
+#include "ShadowRoot.h"
+#include "StyleInvalidationAnalysis.h"
+#include "StyleResolver.h"
+#include "StyleScope.h"
+
+namespace WebCore {
+namespace Style {
+
+static bool mayBeAffectedByAttributeChange(DocumentRuleSets& ruleSets, bool isHTML, const QualifiedName& attributeName)
+{
+    auto& nameSet = isHTML ? ruleSets.features().attributeCanonicalLocalNamesInRules : ruleSets.features().attributeLocalNamesInRules;
+    return nameSet.contains(attributeName.localName());
+}
+
+static bool mayBeAffectedByHostRules(const Element& element, const QualifiedName& attributeName)
+{
+    auto* shadowRoot = element.shadowRoot();
+    if (!shadowRoot)
+        return false;
+    auto& shadowRuleSets = shadowRoot->styleScope().resolver().ruleSets();
+    if (shadowRuleSets.authorStyle().hostPseudoClassRules().isEmpty())
+        return false;
+
+    return mayBeAffectedByAttributeChange(shadowRuleSets, element.isHTMLElement(), attributeName);
+}
+
+static bool mayBeAffectedBySlottedRules(const Element& element, const QualifiedName& attributeName)
+{
+    for (auto* shadowRoot : assignedShadowRootsIfSlotted(element)) {
+        auto& ruleSets = shadowRoot->styleScope().resolver().ruleSets();
+        if (ruleSets.authorStyle().slottedPseudoElementRules().isEmpty())
+            continue;
+        if (mayBeAffectedByAttributeChange(ruleSets, element.isHTMLElement(), attributeName))
+            return true;
+    }
+    return false;
+}
+
+void AttributeChangeInvalidation::invalidateStyle(const QualifiedName& attributeName, const AtomicString& oldValue, const AtomicString& newValue)
+{
+    if (newValue == oldValue)
+        return;
+
+    auto& ruleSets = m_element.styleResolver().ruleSets();
+    bool isHTML = m_element.isHTMLElement();
+
+    bool mayAffectStyle = mayBeAffectedByAttributeChange(ruleSets, isHTML, attributeName)
+        || mayBeAffectedByHostRules(m_element, attributeName)
+        || mayBeAffectedBySlottedRules(m_element, attributeName);
+
+    if (!mayAffectStyle)
+        return;
+
+    if (!isHTML) {
+        m_element.invalidateStyleForSubtree();
+        return;
+    }
+
+    if (m_element.shadowRoot() && ruleSets.authorStyle().hasShadowPseudoElementRules()) {
+        m_element.invalidateStyleForSubtree();
+        return;
+    }
+
+    m_element.invalidateStyle();
+
+    if (!childrenOfType<Element>(m_element).first())
+        return;
+
+    auto* attributeRules = ruleSets.ancestorAttributeRulesForHTML(attributeName.localName());
+    if (!attributeRules)
+        return;
+
+    // Check if descendants may be affected by this attribute change.
+    for (auto* selector : attributeRules->attributeSelectors) {
+        bool oldMatches = oldValue.isNull() ? false : SelectorChecker::attributeSelectorMatches(m_element, attributeName, oldValue, *selector);
+        bool newMatches = newValue.isNull() ? false : SelectorChecker::attributeSelectorMatches(m_element, attributeName, newValue, *selector);
+
+        if (oldMatches != newMatches) {
+            m_descendantInvalidationRuleSet = attributeRules->ruleSet.get();
+            return;
+        }
+    }
+}
+
+void AttributeChangeInvalidation::invalidateDescendants()
+{
+    if (!m_descendantInvalidationRuleSet)
+        return;
+    StyleInvalidationAnalysis invalidationAnalysis(*m_descendantInvalidationRuleSet);
+    invalidationAnalysis.invalidateStyle(m_element);
+}
+
+}
+}