diff -r 000000000000 -r 4f2f89ce4247 WebCore/html/HTMLElementStack.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/html/HTMLElementStack.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) 2010 Google, 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 GOOGLE INC. ``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 GOOGLE INC. OR
+ * 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. 
+ */
+
+#ifndef HTMLElementStack_h
+#define HTMLElementStack_h
+
+#include <wtf/Noncopyable.h>
+#include <wtf/OwnPtr.h>
+#include <wtf/PassOwnPtr.h>
+#include <wtf/RefPtr.h>
+
+namespace WebCore {
+
+class AtomicString;
+class Element;
+class QualifiedName;
+
+// NOTE: The HTML5 spec uses a backwards (grows downward) stack.  We're using
+// more standard (grows upwards) stack terminology here.
+class HTMLElementStack : public Noncopyable {
+public:
+    HTMLElementStack();
+    ~HTMLElementStack();
+
+    class ElementRecord : public Noncopyable {
+    public:
+        ~ElementRecord(); // Public for ~PassOwnPtr()
+    
+        Element* element() const { return m_element.get(); }
+        void replaceElement(PassRefPtr<Element>);
+
+        bool isAbove(ElementRecord*) const;
+
+        ElementRecord* next() const { return m_next.get(); }
+
+    private:
+        friend class HTMLElementStack;
+
+        ElementRecord(PassRefPtr<Element>, PassOwnPtr<ElementRecord>);
+
+        PassOwnPtr<ElementRecord> releaseNext() { return m_next.release(); }
+        void setNext(PassOwnPtr<ElementRecord> next) { m_next = next; }
+
+        RefPtr<Element> m_element;
+        OwnPtr<ElementRecord> m_next;
+    };
+    
+    Element* top() const;
+    Element* oneBelowTop() const;
+    ElementRecord* topRecord() const;
+    Element* bottom() const;
+    ElementRecord* find(Element*) const;
+    ElementRecord* topmost(const AtomicString& tagName) const;
+
+    void insertAbove(PassRefPtr<Element>, ElementRecord*);
+
+    void push(PassRefPtr<Element>);
+    void pushHTMLHtmlElement(PassRefPtr<Element>);
+    void pushHTMLHeadElement(PassRefPtr<Element>);
+    void pushHTMLBodyElement(PassRefPtr<Element>);
+
+    void pop();
+    void popUntil(const AtomicString& tagName);
+    void popUntilElementWithNamespace(const AtomicString& namespaceURI);
+    void popUntil(Element*);
+    void popUntilPopped(const AtomicString& tagName);
+    void popUntilPopped(Element*);
+    void popUntilTableScopeMarker(); // "clear the stack back to a table context" in the spec.
+    void popUntilTableBodyScopeMarker(); // "clear the stack back to a table body context" in the spec.
+    void popUntilTableRowScopeMarker(); // "clear the stack back to a table row context" in the spec.
+    void popHTMLHeadElement();
+    void popHTMLBodyElement();
+    void popAll();
+
+    void remove(Element*);
+    void removeHTMLHeadElement(Element*);
+
+    bool contains(Element*) const;
+    bool contains(const AtomicString& tagName) const;
+
+    bool inScope(Element*) const;
+    bool inScope(const AtomicString& tagName) const;
+    bool inScope(const QualifiedName&) const;
+    bool inListItemScope(const AtomicString& tagName) const;
+    bool inListItemScope(const QualifiedName&) const;
+    bool inTableScope(const AtomicString& tagName) const;
+    bool inTableScope(const QualifiedName&) const;
+    bool inButtonScope(const AtomicString& tagName) const;
+    bool inButtonScope(const QualifiedName&) const;
+
+    bool hasOnlyHTMLElementsInScope() const;
+
+    Element* htmlElement() const;
+    Element* headElement() const;
+    Element* bodyElement() const;
+
+#ifndef NDEBUG
+    void show();
+#endif
+
+private:
+    void pushCommon(PassRefPtr<Element>);
+    void popCommon();
+    void removeNonTopCommon(Element*);
+
+    OwnPtr<ElementRecord> m_top;
+
+    // We remember <html>, <head> and <body> as they are pushed.  Their
+    // ElementRecords keep them alive.  <html> is never popped.
+    // FIXME: We don't currently require type-specific information about
+    // these elements so we haven't yet bothered to plumb the types all the
+    // way down through createElement, etc.
+    Element* m_htmlElement;
+    Element* m_headElement;
+    Element* m_bodyElement;
+};
+
+} // namespace WebCore
+
+#endif // HTMLElementStack_h