1 /*
2  * Copyright (C) 2008, 2009, 2010 Apple Inc. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
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9  *     notice, this list of conditions and the following disclaimer.
10  * 2.  Redistributions in binary form must reproduce the above copyright
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12  *     documentation and/or other materials provided with the distribution.
13  * 3.  Neither the name of Apple Computer, 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.
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17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
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19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "third_party/blink/renderer/core/accessibility/ax_object_cache.h"
30 
31 #include <memory>
32 
33 #include "base/memory/ptr_util.h"
34 #include "base/stl_util.h"
35 #include "third_party/blink/public/web/web_ax_enums.h"
36 #include "third_party/blink/renderer/core/dom/element.h"
37 #include "third_party/blink/renderer/core/dom/node.h"
38 #include "third_party/blink/renderer/core/html_element_type_helpers.h"
39 #include "third_party/blink/renderer/platform/wtf/assertions.h"
40 #include "third_party/blink/renderer/platform/wtf/hash_set.h"
41 #include "third_party/blink/renderer/platform/wtf/text/string_hash.h"
42 #include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
43 
44 namespace blink {
45 
46 AXObjectCache::AXObjectCacheCreateFunction AXObjectCache::create_function_ =
47     nullptr;
48 
Init(AXObjectCacheCreateFunction function)49 void AXObjectCache::Init(AXObjectCacheCreateFunction function) {
50   DCHECK(!create_function_);
51   create_function_ = function;
52 }
53 
Create(Document & document)54 AXObjectCache* AXObjectCache::Create(Document& document) {
55   DCHECK(create_function_);
56   return create_function_(document);
57 }
58 
59 namespace {
60 
61 typedef HashSet<String, CaseFoldingHash> ARIAWidgetSet;
62 
63 const char* g_aria_widgets[] = {
64     // From http://www.w3.org/TR/wai-aria/roles#widget_roles
65     "alert", "alertdialog", "button", "checkbox", "dialog", "gridcell", "link",
66     "log", "marquee", "menuitem", "menuitemcheckbox", "menuitemradio", "option",
67     "progressbar", "radio", "scrollbar", "slider", "spinbutton", "status",
68     "tab", "tabpanel", "textbox", "timer", "tooltip", "treeitem",
69     // Composite user interface widgets.
70     // This list is also from the w3.org site referenced above.
71     "combobox", "grid", "listbox", "menu", "menubar", "radiogroup", "tablist",
72     "tree", "treegrid"};
73 
CreateARIARoleWidgetSet()74 static ARIAWidgetSet* CreateARIARoleWidgetSet() {
75   ARIAWidgetSet* widget_set = new HashSet<String, CaseFoldingHash>();
76   for (size_t i = 0; i < base::size(g_aria_widgets); ++i)
77     widget_set->insert(String(g_aria_widgets[i]));
78   return widget_set;
79 }
80 
IncludesARIAWidgetRole(const String & role)81 bool IncludesARIAWidgetRole(const String& role) {
82   static const HashSet<String, CaseFoldingHash>* role_set =
83       CreateARIARoleWidgetSet();
84 
85   Vector<String> role_vector;
86   role.Split(' ', role_vector);
87   for (const auto& child : role_vector) {
88     if (role_set->Contains(child))
89       return true;
90   }
91   return false;
92 }
93 
94 const char* g_aria_interactive_widget_attributes[] = {
95     // These attributes implicitly indicate the given widget is interactive.
96     // From http://www.w3.org/TR/wai-aria/states_and_properties#attrs_widgets
97     // clang-format off
98     "aria-activedescendant",
99     "aria-checked",
100     "aria-controls",
101     "aria-disabled",  // If it's disabled, it can be made interactive.
102     "aria-haspopup",
103     "aria-multiselectable",
104     "aria-required",
105     "aria-selected"
106     // clang-format on
107 };
108 
HasInteractiveARIAAttribute(const Element & element)109 bool HasInteractiveARIAAttribute(const Element& element) {
110   for (size_t i = 0; i < base::size(g_aria_interactive_widget_attributes);
111        ++i) {
112     const char* attribute = g_aria_interactive_widget_attributes[i];
113     if (element.hasAttribute(attribute)) {
114       return true;
115     }
116   }
117   return false;
118 }
119 
120 }  // namespace
121 
IsInsideFocusableElementOrARIAWidget(const Node & node)122 bool AXObjectCache::IsInsideFocusableElementOrARIAWidget(const Node& node) {
123   const Node* cur_node = &node;
124   do {
125     if (const auto* element = DynamicTo<Element>(cur_node)) {
126       if (element->IsFocusable())
127         return true;
128       String role = element->getAttribute("role");
129       if (!role.IsEmpty() && IncludesARIAWidgetRole(role))
130         return true;
131       if (HasInteractiveARIAAttribute(*element))
132         return true;
133     }
134     cur_node = cur_node->parentNode();
135   } while (cur_node && !IsA<HTMLBodyElement>(node));
136   return false;
137 }
138 
139 }  // namespace blink
140