Source/WebCore/page/scrolling/ScrollingTreeNode.cpp

/*
 * Copyright (C) 2012-2022 Apple Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
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 * 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
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#include "config.h"
#include "ScrollingTreeNode.h"

#if ENABLE(ASYNC_SCROLLING)

#include "ScrollingStateTree.h"
#include "ScrollingTree.h"
#include "ScrollingTreeFrameScrollingNode.h"
#include <wtf/text/TextStream.h>

namespace WebCore {

ScrollingTreeNode::ScrollingTreeNode(ScrollingTree& scrollingTree, ScrollingNodeType nodeType, ScrollingNodeID nodeID)
    : m_scrollingTree(scrollingTree)
    , m_nodeType(nodeType)
    , m_nodeID(nodeID)
{
}

ScrollingTreeNode::~ScrollingTreeNode() = default;

void ScrollingTreeNode::appendChild(Ref<ScrollingTreeNode>&& childNode)
{
    RELEASE_ASSERT(m_scrollingTree.inCommitTreeState());

    childNode->setParent(this);

    m_children.append(WTFMove(childNode));
}

void ScrollingTreeNode::removeChild(ScrollingTreeNode& node)
{
    RELEASE_ASSERT(m_scrollingTree.inCommitTreeState());

    size_t index = m_children.findIf([&](auto& child) {
        return &node == child.ptr();
    });

    // The index will be notFound if the node to remove is a deeper-than-1-level descendant or
    // if node is the root state node.
    if (index != notFound) {
        m_children.remove(index);
        return;
    }

    for (auto& child : m_children)
        child->removeChild(node);
}

void ScrollingTreeNode::removeAllChildren()
{
    RELEASE_ASSERT(m_scrollingTree.inCommitTreeState());

    m_children.clear();
}

bool ScrollingTreeNode::isRootNode() const
{
    return m_scrollingTree.rootNode() == this;
}

void ScrollingTreeNode::dumpProperties(TextStream& ts, OptionSet<ScrollingStateTreeAsTextBehavior> behavior) const
{
    if (behavior & ScrollingStateTreeAsTextBehavior::IncludeNodeIDs)
        ts.dumpProperty("nodeID", scrollingNodeID());
}

ScrollingTreeFrameScrollingNode* ScrollingTreeNode::enclosingFrameNodeIncludingSelf()
{
    auto* node = this;
    while (node && !node->isFrameScrollingNode())
        node = node->parent();

    return downcast<ScrollingTreeFrameScrollingNode>(node);
}

ScrollingTreeScrollingNode* ScrollingTreeNode::enclosingScrollingNodeIncludingSelf()
{
    auto* node = this;
    while (node && !node->isScrollingNode())
        node = node->parent();

    return downcast<ScrollingTreeScrollingNode>(node);
}

void ScrollingTreeNode::dump(TextStream& ts, OptionSet<ScrollingStateTreeAsTextBehavior> behavior) const
{
    dumpProperties(ts, behavior);

    for (auto& child : m_children) {
        TextStream::GroupScope scope(ts);
        child->dump(ts, behavior);
    }
}

} // namespace WebCore

#endif // ENABLE(ASYNC_SCROLLING)