third_party/WebKit/Source/core/events/TreeScopeEventContext.cpp

/*
 * Copyright (C) 2014 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 APPLE COMPUTER, 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 APPLE COMPUTER, 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
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#include "core/events/TreeScopeEventContext.h"

#include "core/dom/StaticNodeList.h"
#include "core/dom/shadow/ShadowRoot.h"
#include "core/events/EventPath.h"
#include "core/events/TouchEventContext.h"

namespace blink {

bool TreeScopeEventContext::isUnclosedTreeOf(const TreeScopeEventContext& other)
{
    // Exclude closed nodes if necessary.
    // If a node is in a closed shadow root, or in a tree whose ancestor has a closed shadow root,
    // it should not be visible to nodes above the closed shadow root.

    // (1) If |this| is an ancestor of |other| in tree-of-trees, include it.
    if (isInclusiveAncestorOf(other))
        return true;

    // (2) If no closed shadow root in ancestors of this, include it.
    if (!containingClosedShadowTree())
        return true;

    // (3) If |this| is descendent of |other|, exclude if any closed shadow root in between.
    if (isDescendantOf(other))
        return !containingClosedShadowTree()->isDescendantOf(other);

    // (4) |this| and |other| must be in exclusive branches.
    ASSERT(other.isExclusivePartOf(*this));
    return false;
}

HeapVector<Member<EventTarget>>& TreeScopeEventContext::ensureEventPath(EventPath& path)
{
    if (m_eventPath)
        return *m_eventPath;

    m_eventPath = new HeapVector<Member<EventTarget>>();
    LocalDOMWindow* window = path.windowEventContext().window();
    m_eventPath->reserveCapacity(path.size() + (window ? 1 : 0));

    for (size_t i = 0; i < path.size(); ++i) {
        if (path[i].treeScopeEventContext().isUnclosedTreeOf(*this))
            m_eventPath->append(path[i].node());
    }
    if (window)
        m_eventPath->append(window);
    return *m_eventPath;
}

TouchEventContext* TreeScopeEventContext::ensureTouchEventContext()
{
    if (!m_touchEventContext)
        m_touchEventContext = TouchEventContext::create();
    return m_touchEventContext.get();
}

TreeScopeEventContext* TreeScopeEventContext::create(TreeScope& treeScope)
{
    return new TreeScopeEventContext(treeScope);
}

TreeScopeEventContext::TreeScopeEventContext(TreeScope& treeScope)
    : m_treeScope(treeScope)
    , m_rootNode(treeScope.rootNode())
    , m_containingClosedShadowTree(nullptr)
    , m_preOrder(-1)
    , m_postOrder(-1)
{
}

DEFINE_TRACE(TreeScopeEventContext)
{
    visitor->trace(m_treeScope);
    visitor->trace(m_rootNode);
    visitor->trace(m_target);
    visitor->trace(m_relatedTarget);
    visitor->trace(m_eventPath);
    visitor->trace(m_touchEventContext);
    visitor->trace(m_containingClosedShadowTree);
    visitor->trace(m_children);
}

int TreeScopeEventContext::calculateTreeOrderAndSetNearestAncestorClosedTree(int orderNumber, TreeScopeEventContext* nearestAncestorClosedTreeScopeEventContext)
{
    m_preOrder = orderNumber;
    m_containingClosedShadowTree = (rootNode().isShadowRoot() && !toShadowRoot(rootNode()).isOpenOrV0()) ? this : nearestAncestorClosedTreeScopeEventContext;
    for (size_t i = 0; i < m_children.size(); ++i)
        orderNumber = m_children[i]->calculateTreeOrderAndSetNearestAncestorClosedTree(orderNumber + 1, containingClosedShadowTree());
    m_postOrder = orderNumber + 1;

    return orderNumber + 1;
}

} // namespace blink