Source/WebCore/rendering/updating/RenderTreeBuilderMultiColumn.h

/*
 * Copyright (C) 2017 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.
 */

#pragma once

#include "RenderTreeBuilder.h"

namespace WebCore {

class RenderBlockFlow;
class RenderMultiColumnFlow;

class RenderTreeBuilder::MultiColumn {
    WTF_MAKE_FAST_ALLOCATED;
public:
    MultiColumn(RenderTreeBuilder&);

    void updateAfterDescendants(RenderBlockFlow&);
    // Some renderers (column spanners) are moved out of the flow thread to live among column
    // sets. If |child| is such a renderer, resolve it to the placeholder that lives at the original
    // location in the tree.
    RenderObject* resolveMovedChild(RenderFragmentedFlow& enclosingFragmentedFlow, RenderObject* beforeChild);
    void restoreColumnSpannersForContainer(const RenderElement& container, RenderMultiColumnFlow&);
    void multiColumnDescendantInserted(RenderMultiColumnFlow&, RenderObject& newDescendant);
    void multiColumnRelativeWillBeRemoved(RenderMultiColumnFlow&, RenderObject& relative, RenderTreeBuilder::CanCollapseAnonymousBlock);
    static RenderObject* adjustBeforeChildForMultiColumnSpannerIfNeeded(RenderObject& beforeChild);

private:
    void createFragmentedFlow(RenderBlockFlow&);
    void destroyFragmentedFlow(RenderBlockFlow&);
    RenderObject* processPossibleSpannerDescendant(RenderMultiColumnFlow&, RenderObject*& subtreeRoot, RenderObject& descendant);
    void handleSpannerRemoval(RenderMultiColumnFlow&, RenderObject& spanner, RenderTreeBuilder::CanCollapseAnonymousBlock);

    RenderTreeBuilder& m_builder;
};

}