/*

 * Copyright (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)

 * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public License

 * along with this library; see the file COPYING.LIB.  If not, write to

 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 *

*/

#ifndef CounterNode_h

#define CounterNode_h

#include <wtf/Noncopyable.h>

// This implements a counter tree that is used for finding parents in counters() lookup,

// and for propagating count changes when nodes are added or removed.

// Parents represent unique counters and their scope, which are created either explicitly

// by "counter-reset" style rules or implicitly by referring to a counter that is not in scope.

// Such nodes are tagged as "reset" nodes, although they are not all due to "counter-reset".

// Not that render tree children are often counter tree siblings due to counter scoping rules.

namespace WebCore {

class AtomicString;

class RenderObject;

class CounterNode : public Noncopyable {

public:

    CounterNode(RenderObject*, bool isReset, int value);

    bool actsAsReset() const { return m_hasResetType || !m_parent; }

    bool hasResetType() const { return m_hasResetType; }

    int value() const { return m_value; }

    int countInParent() const { return m_countInParent; }

    RenderObject* renderer() const { return m_renderer; }

    CounterNode* parent() const { return m_parent; }

    CounterNode* previousSibling() const { return m_previousSibling; }

    CounterNode* nextSibling() const { return m_nextSibling; }

    CounterNode* firstChild() const { return m_firstChild; }

    CounterNode* lastChild() const { return m_lastChild; }

    CounterNode* lastDescendant() const;

    CounterNode* previousInPreOrder() const;

    CounterNode* nextInPreOrder(const CounterNode* stayWithin = 0) const;

    CounterNode* nextInPreOrderAfterChildren(const CounterNode* stayWithin = 0) const;

    void insertAfter(CounterNode* newChild, CounterNode* beforeChild, const AtomicString& identifier);

    // identifier must match the identifier of this counter.

    void removeChild(CounterNode*, const AtomicString& identifier);

private:

    int computeCountInParent() const;

    void recount(const AtomicString& identifier);

    // Invalidates the text in the renderer of this counter, if any.

    // identifier must match the identifier of this counter.

    void resetRenderer(const AtomicString& identifier) const;

    // Invalidates the text in the renderer of this counter, if any,

    // and in the renderers of all descendants of this counter, if any.

    // identifier must match the identifier of this counter.

    void resetRenderers(const AtomicString& identifier) const;

    bool m_hasResetType;

    int m_value;

    int m_countInParent;

    RenderObject* m_renderer;

    CounterNode* m_parent;

    CounterNode* m_previousSibling;

    CounterNode* m_nextSibling;

    CounterNode* m_firstChild;

    CounterNode* m_lastChild;

};

} // namespace WebCore

#ifndef NDEBUG

// Outside the WebCore namespace for ease of invocation from gdb.

void showTree(const WebCore::CounterNode*);

#endif

#endif // CounterNode_h