Source/WebCore/style/RenderTreePosition.h

/*
 * Copyright (C) 2015 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.
 */

#ifndef RenderTreePosition_h
#define RenderTreePosition_h

#include "RenderElement.h"
#include "RenderText.h"
#include "RenderView.h"

namespace WebCore {

class RenderTreePosition {
public:
    explicit RenderTreePosition(RenderView& root)
        : m_parent(root)
        , m_hasValidNextSibling(true)
    {
    }
    
    explicit RenderTreePosition(RenderElement& parent)
        : m_parent(parent)
    {
    }
    
    RenderTreePosition(RenderElement& parent, RenderObject* nextSibling)
        : m_parent(parent)
        , m_nextSibling(nextSibling)
        , m_hasValidNextSibling(true)
    {
    }

    RenderElement& parent() const { return m_parent; }

    void insert(RenderObject&);
    bool canInsert(RenderElement&) const;
    bool canInsert(RenderText&) const;

    void computeNextSibling(const Node&);
    void invalidateNextSibling() { m_hasValidNextSibling = false; }
    void invalidateNextSibling(const RenderObject&);

    RenderObject* previousSiblingRenderer(const Text&) const;
    RenderObject* nextSiblingRenderer(const Node&) const;
    static bool isRendererReparented(const RenderObject&);

private:
    RenderElement& m_parent;
    RenderObject* m_nextSibling { nullptr };
    bool m_hasValidNextSibling { false };
#if !ASSERT_DISABLED
    unsigned m_assertionLimitCounter { 0 };
#endif
};

inline bool RenderTreePosition::canInsert(RenderElement& renderer) const
{
    ASSERT(!renderer.parent());
    return m_parent.isChildAllowed(renderer, renderer.style());
}

inline bool RenderTreePosition::canInsert(RenderText& renderer) const
{
    ASSERT(!renderer.parent());
    return m_parent.isChildAllowed(renderer, m_parent.style());
}

inline void RenderTreePosition::insert(RenderObject& renderer)
{
    ASSERT(m_hasValidNextSibling);
    m_parent.addChild(&renderer, m_nextSibling);
}

}

#endif