root/Source/core/dom/NodeRenderingTraversal.cpp

DEFINITIONS

1. isRendererReparented
2. didTraverseInsertionPoint
3. parent
4. contains
5. nextSibling
6. previousSibling
7. lastChild
8. pseudoAwarePreviousSibling
9. pseudoAwareLastChild
10. previous
11. firstChild
12. pseudoAwareNextSibling
13. pseudoAwareFirstChild
14. next
15. nextSiblingRenderer
16. previousSiblingRenderer
17. nextInTopLayer

/*
 * Copyright (C) 2012 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:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
 * OWNER 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 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.
 */

#include "config.h"
#include "core/dom/NodeRenderingTraversal.h"

#include "HTMLNames.h"
#include "core/dom/PseudoElement.h"
#include "core/dom/shadow/ComposedTreeWalker.h"
#include "core/rendering/RenderObject.h"

namespace WebCore {

namespace NodeRenderingTraversal {

static bool isRendererReparented(const RenderObject* renderer)
{
    if (!renderer->node()->isElementNode())
        return false;
    if (toElement(renderer->node())->isInTopLayer())
        return true;
    return false;
}

void ParentDetails::didTraverseInsertionPoint(const InsertionPoint* insertionPoint)
{
    if (!m_insertionPoint) {
        m_insertionPoint = insertionPoint;
    }
}

ContainerNode* parent(const Node* node, ParentDetails* details)
{
    // FIXME: We should probably ASSERT(!node->document().childNeedsDistributionRecalc()) here, but
    // a bunch of things use NodeRenderingTraversal::parent in places where that looks like it could
    // be false.
    ASSERT(node);
    if (isActiveInsertionPoint(*node))
        return 0;
    ComposedTreeWalker walker(node, ComposedTreeWalker::CanStartFromShadowBoundary);
    return toContainerNode(walker.traverseParent(walker.get(), details));
}

bool contains(const ContainerNode* container, const Node* node)
{
    while (node) {
        if (node == container)
            return true;
        node = NodeRenderingTraversal::parent(node);
    }
    return false;
}

Node* nextSibling(const Node* node)
{
    ComposedTreeWalker walker(node);
    if (node->isBeforePseudoElement()) {
        walker.parent();
        walker.firstChild();
    } else
        walker.nextSibling();

    if (walker.get() || node->isAfterPseudoElement())
        return walker.get();

    Node* parent = walker.traverseParent(node);
    if (parent && parent->isElementNode())
        return toElement(parent)->pseudoElement(AFTER);

    return 0;
}

Node* previousSibling(const Node* node)
{
    ComposedTreeWalker walker(node);
    if (node->isAfterPseudoElement()) {
        walker.parent();
        walker.lastChild();
    } else
        walker.previousSibling();

    if (walker.get() || node->isBeforePseudoElement())
        return walker.get();

    Node* parent = walker.traverseParent(node);
    if (parent && parent->isElementNode())
        return toElement(parent)->pseudoElement(BEFORE);

    return 0;
}

static Node* lastChild(const Node* node)
{
    ComposedTreeWalker walker(node);
    walker.lastChild();
    return walker.get();
}

static Node* pseudoAwarePreviousSibling(const Node* node)
{
    Node* previousNode = previousSibling(node);
    Node* parentNode = parent(node);

    if (parentNode && parentNode->isElementNode() && !previousNode) {
        if (node->isAfterPseudoElement()) {
            if (Node* child = lastChild(parentNode))
                return child;
        }
        if (!node->isBeforePseudoElement())
            return toElement(parentNode)->pseudoElement(BEFORE);
    }
    return previousNode;
}

static Node* pseudoAwareLastChild(const Node* node)
{
    if (node->isElementNode()) {
        const Element* currentElement = toElement(node);
        Node* last = currentElement->pseudoElement(AFTER);
        if (last)
            return last;

        last = lastChild(currentElement);
        if (!last)
            last = currentElement->pseudoElement(BEFORE);
        return last;
    }

    return lastChild(node);
}

Node* previous(const Node* node, const Node* stayWithin)
{
    if (node == stayWithin)
        return 0;

    if (Node* previousNode = pseudoAwarePreviousSibling(node)) {
        while (Node* previousLastChild = pseudoAwareLastChild(previousNode))
            previousNode = previousLastChild;
        return previousNode;
    }
    return parent(node);
}

static Node* firstChild(const Node* node)
{
    ComposedTreeWalker walker(node);
    walker.firstChild();
    return walker.get();
}

static Node* pseudoAwareNextSibling(const Node* node)
{
    Node* parentNode = parent(node);
    Node* nextNode = nextSibling(node);

    if (parentNode && parentNode->isElementNode() && !nextNode) {
        if (node->isBeforePseudoElement()) {
            if (Node* child = firstChild(parentNode))
                return child;
        }
        if (!node->isAfterPseudoElement())
            return toElement(parentNode)->pseudoElement(AFTER);
    }
    return nextNode;
}

static Node* pseudoAwareFirstChild(const Node* node)
{
    if (node->isElementNode()) {
        const Element* currentElement = toElement(node);
        Node* first = currentElement->pseudoElement(BEFORE);
        if (first)
            return first;
        first = firstChild(currentElement);
        if (!first)
            first = currentElement->pseudoElement(AFTER);
        return first;
    }

    return firstChild(node);
}

Node* next(const Node* node, const Node* stayWithin)
{
    if (Node* child = pseudoAwareFirstChild(node))
        return child;
    if (node == stayWithin)
        return 0;
    if (Node* nextNode = pseudoAwareNextSibling(node))
        return nextNode;
    for (Node* parentNode = parent(node); parentNode; parentNode = parent(parentNode)) {
        if (parentNode == stayWithin)
            return 0;
        if (Node* nextNode = pseudoAwareNextSibling(parentNode))
            return nextNode;
    }
    return 0;
}

RenderObject* nextSiblingRenderer(const Node* node)
{
    for (Node* sibling = NodeRenderingTraversal::nextSibling(node); sibling; sibling = NodeRenderingTraversal::nextSibling(sibling)) {
        RenderObject* renderer = sibling->renderer();
        if (renderer && !isRendererReparented(renderer))
            return renderer;
    }
    return 0;
}

RenderObject* previousSiblingRenderer(const Node* node)
{
    for (Node* sibling = NodeRenderingTraversal::previousSibling(node); sibling; sibling = NodeRenderingTraversal::previousSibling(sibling)) {
        RenderObject* renderer = sibling->renderer();
        if (renderer && !isRendererReparented(renderer))
            return renderer;
    }
    return 0;
}

RenderObject* nextInTopLayer(const Element* element)
{
    if (!element->isInTopLayer())
        return 0;
    const Vector<RefPtr<Element> >& topLayerElements = element->document().topLayerElements();
    size_t position = topLayerElements.find(element);
    ASSERT(position != kNotFound);
    for (size_t i = position + 1; i < topLayerElements.size(); ++i) {
        if (RenderObject* renderer = topLayerElements[i]->renderer())
            return renderer;
    }
    return 0;
}

}

} // namespace