1/*
2 * Copyright (C) 2015 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of Apple Inc. ("Apple") nor the names of
14 * its contributors may be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include "config.h"
30#include "AccessibilityTree.h"
31
32#include "AXObjectCache.h"
33#include "AccessibilityTreeItem.h"
34#include "Element.h"
35#include "HTMLNames.h"
36
37#include <wtf/Deque.h>
38
39namespace WebCore {
40
41using namespace HTMLNames;
42
43AccessibilityTree::AccessibilityTree(RenderObject* renderer)
44 : AccessibilityRenderObject(renderer)
45{
46}
47
48AccessibilityTree::~AccessibilityTree() = default;
49
50Ref<AccessibilityTree> AccessibilityTree::create(RenderObject* renderer)
51{
52 return adoptRef(*new AccessibilityTree(renderer));
53}
54
55bool AccessibilityTree::computeAccessibilityIsIgnored() const
56{
57 return accessibilityIsIgnoredByDefault();
58}
59
60AccessibilityRole AccessibilityTree::determineAccessibilityRole()
61{
62 if ((m_ariaRole = determineAriaRoleAttribute()) != AccessibilityRole::Tree)
63 return AccessibilityRenderObject::determineAccessibilityRole();
64
65 return isTreeValid() ? AccessibilityRole::Tree : AccessibilityRole::Group;
66}
67
68bool AccessibilityTree::nodeHasTreeItemChild(Node& node) const
69{
70 for (auto* child = node.firstChild(); child; child = child->nextSibling()) {
71 if (nodeHasRole(child, "treeitem"))
72 return true;
73 }
74 return false;
75}
76
77bool AccessibilityTree::isTreeValid() const
78{
79 // A valid tree can only have treeitem or group of treeitems as a child
80 // http://www.w3.org/TR/wai-aria/roles#tree
81
82 Node* node = this->node();
83 if (!node)
84 return false;
85
86 Deque<Node*> queue;
87 for (auto* child = node->firstChild(); child; child = child->nextSibling())
88 queue.append(child);
89
90 while (!queue.isEmpty()) {
91 auto child = queue.takeFirst();
92
93 if (!is<Element>(*child))
94 continue;
95 if (nodeHasRole(child, "treeitem"))
96 continue;
97 if (nodeHasRole(child, "presentation")) {
98 if (!nodeHasTreeItemChild(*child))
99 return false;
100 continue;
101 }
102 if (!nodeHasRole(child, "group"))
103 return false;
104
105 for (auto* groupChild = child->firstChild(); groupChild; groupChild = groupChild->nextSibling())
106 queue.append(groupChild);
107 }
108 return true;
109}
110
111} // namespace WebCore
112