Source/WebCore/accessibility/AccessibilityTree.cpp

/*
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 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
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#include "config.h"
#include "AccessibilityTree.h"

#include "AXObjectCache.h"
#include "AccessibilityTreeItem.h"
#include "Element.h"
#include "HTMLNames.h"
#include "NodeInlines.h"
#include <wtf/Deque.h>

namespace WebCore {

using namespace HTMLNames;
    
AccessibilityTree::AccessibilityTree(AXID axID, RenderObject& renderer, AXObjectCache& cache)
    : AccessibilityRenderObject(axID, renderer, cache)
{
}

AccessibilityTree::AccessibilityTree(AXID axID, Node& node, AXObjectCache& cache)
    : AccessibilityRenderObject(axID, node, cache)
{
}

AccessibilityTree::~AccessibilityTree() = default;
    
Ref<AccessibilityTree> AccessibilityTree::create(AXID axID, RenderObject& renderer, AXObjectCache& cache)
{
    return adoptRef(*new AccessibilityTree(axID, renderer, cache));
}

Ref<AccessibilityTree> AccessibilityTree::create(AXID axID, Node& node, AXObjectCache& cache)
{
    return adoptRef(*new AccessibilityTree(axID, node, cache));
}

bool AccessibilityTree::computeIsIgnored() const
{
    return isIgnoredByDefault();
}

AccessibilityRole AccessibilityTree::determineAccessibilityRole()
{
    if ((m_ariaRole = determineAriaRoleAttribute()) != AccessibilityRole::Tree)
        return AccessibilityRenderObject::determineAccessibilityRole();

    return isTreeValid() ? AccessibilityRole::Tree : AccessibilityRole::Generic;
}

bool AccessibilityTree::isTreeValid() const
{
    // A valid tree can only have treeitem or group of treeitems as a child.
    // https://www.w3.org/TR/wai-aria/#tree
    RefPtr node = this->node();
    if (!node)
        return false;
    
    Deque<Ref<Node>> queue;
    for (RefPtr child = node->firstChild(); child; child = queue.last()->nextSibling())
        queue.append(child.releaseNonNull());

    while (!queue.isEmpty()) {
        Ref child = queue.takeFirst();

        RefPtr childElement = dynamicDowncast<Element>(child);
        if (!childElement)
            continue;
        if (hasRole(*childElement, "treeitem"_s))
            continue;
        if (!hasAnyRole(*childElement, { "group"_s, "presentation"_s }))
            return false;

        for (RefPtr groupChild = child->firstChild(); groupChild; groupChild = queue.last()->nextSibling())
            queue.append(groupChild.releaseNonNull());
    }
    return true;
}

} // namespace WebCore