Android: Talkback fix nesting level for single-level lists

Talkback would previously report nesting level for single-level lists,
which was considered unnecessary. Added functionality in the
IsHierarchical() method to determine if a list contains other lists,
or if it is contained within a list, to help determine if it is
hierarchical. Also modified DumpAccessibilityTree test expected output
files to check for new desired behavior.


R=dmazzoni@chromium.org

Bug: 591255
Change-Id: Idd995c5fae426b191825996cf02ee51bd6753607
Reviewed-on: https://chromium-review.googlesource.com/c/1300076
Commit-Queue: Akihiro Ota <akihiroota@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#603624}

content/browser/accessibility/browser_accessibility_android.cc

@@ -51,6 +51,53 @@ enum {
   ANDROID_VIEW_ACCESSIBILITY_RANGE_TYPE_FLOAT = 1
 };
 
+static bool HasListAncestor(const content::BrowserAccessibility* node) {
+  if (node == nullptr)
+    return false;  // Base case
+
+  if (ui::IsStaticList(node->GetRole()))
+    return true;
+
+  return HasListAncestor(node->InternalGetParent());
+}
+
+static bool HasListDescendant(const content::BrowserAccessibility* current,
+                              const content::BrowserAccessibility* root) {
+  // Only check role of descendants
+  if (current != root) {
+    if (ui::IsStaticList(current->GetRole()))
+      return true;
+  }
+
+  int num_children = current->InternalChildCount();
+
+  for (int i = 0; i < num_children; ++i) {
+    if (HasListDescendant(current->InternalGetChild(i), root))
+      return true;
+  }
+  return false;
+}
+
+/*
+Determines:
+1. If this is an ancestor of any lists
+2. If this list is a descendant of any lists
+Talkback uses this information to report if the list has levels, and if so,
+which level is currently selected
+*/
+static bool IsHierarchicalList(const content::BrowserAccessibility* node) {
+  // Only makes sense to run if |node| is already a list
+  DCHECK(ui::IsStaticList(node->GetRole()));
+
+  if (node == nullptr)
+    return false;
+
+  bool found_list_in_descendants = HasListDescendant(node, node);
+  bool found_list_in_ancestors = HasListAncestor(node->InternalGetParent());
+
+  return (found_list_in_descendants || found_list_in_ancestors);
+}
+
 }  // namespace
 
 namespace content {
@@ -256,9 +303,8 @@ bool BrowserAccessibilityAndroid::IsHeading() const {
 }
 
 bool BrowserAccessibilityAndroid::IsHierarchical() const {
-  return (GetRole() == ax::mojom::Role::kList ||
-          GetRole() == ax::mojom::Role::kDescriptionList ||
-          GetRole() == ax::mojom::Role::kTree);
+  return (GetRole() == ax::mojom::Role::kTree ||
+          (ui::IsStaticList(GetRole()) && IsHierarchicalList(this)));
 }
 
 bool BrowserAccessibilityAndroid::IsLink() const {

content/browser/accessibility/dump_accessibility_tree_browsertest.cc

@@ -1874,6 +1874,10 @@ IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest,
   RunHtmlTest(FILE_PATH_LITERAL("label-with-presentational-child.html"));
 }
 
+IN_PROC_BROWSER_TEST_F(DumpAccessibilityTreeTest, AccessibilityNestedList) {
+  RunHtmlTest(FILE_PATH_LITERAL("nestedlist.html"));
+}
+
 //
 // Regression tests. These don't test a specific web platform feature,
 // they test a specific web page that crashed or had some bad behavior

content/test/data/accessibility/aria/aria-directory-expected-android.txt

 android.webkit.WebView focusable focused scrollable
-++android.widget.ListView collection hierarchical
+++android.widget.ListView collection

content/test/data/accessibility/aria/aria-dropeffect-expected-android.txt

 android.webkit.WebView focusable focused scrollable
-++android.widget.ListView collection hierarchical item_count=7 row_count=7
+++android.widget.ListView collection item_count=7 row_count=7
 ++++android.view.View collection_item
 ++++++android.view.View name='• '
 ++++++android.view.View name='copy'
@@ -20,4 +20,4 @@ android.webkit.WebView focusable focused scrollable
 ++++++android.view.View name='none(default)'
 ++++android.view.View collection_item item_index=6 row_index=6
 ++++++android.view.View name='• '
-++++++android.view.View name='link'
+++++++android.view.View name='link'
\ No newline at end of file

content/test/data/accessibility/aria/aria-grabbed-expected-android.txt

 android.webkit.WebView focusable focused scrollable
-++android.widget.ListView collection hierarchical item_count=3 row_count=3
+++android.widget.ListView collection item_count=3 row_count=3
 ++++android.view.View collection_item
 ++++++android.view.View name='• '
 ++++++android.view.View name='grabbed-true '
@@ -11,4 +11,4 @@ android.webkit.WebView focusable focused scrollable
 ++++android.view.View collection_item item_index=2 row_index=2
 ++++++android.view.View name='• '
 ++++++android.view.View name='grabbed-undefined '
-++++++android.widget.Image role_description='graphic' name='blue'
+++++++android.widget.Image role_description='graphic' name='blue'
\ No newline at end of file

content/test/data/accessibility/aria/aria-list-expected-android.txt

 android.webkit.WebView focusable focused scrollable
-++android.widget.ListView collection hierarchical item_count=3 row_count=3
+++android.widget.ListView collection item_count=3 row_count=3
 ++++android.view.View collection_item name='1'
 ++++android.view.View collection_item name='2' item_index=1 row_index=1
-++++android.view.View collection_item name='3' item_index=2 row_index=2
+++++android.view.View collection_item name='3' item_index=2 row_index=2
\ No newline at end of file

content/test/data/accessibility/aria/aria-listitem-expected-android.txt

 android.webkit.WebView focusable focused scrollable
-++android.widget.ListView collection hierarchical item_count=2 row_count=2
+++android.widget.ListView collection item_count=2 row_count=2
 ++++android.view.View collection_item name='1'
-++++android.view.View collection_item name='2' item_index=1 row_index=1
+++++android.view.View collection_item name='2' item_index=1 row_index=1
\ No newline at end of file

content/test/data/accessibility/html/dd-expected-android.txt

 android.webkit.WebView focusable focused scrollable
-++android.widget.ListView collection hierarchical item_count=2 row_count=2
+++android.widget.ListView collection item_count=2 row_count=2
 ++++android.view.View collection_item name='Coffee'
-++++android.view.View role_description='definition' name='Black hot drink'
+++++android.view.View role_description='definition' name='Black hot drink'
\ No newline at end of file

content/test/data/accessibility/html/dl-expected-android.txt

 android.webkit.WebView focusable focused scrollable
-++android.widget.ListView collection hierarchical item_count=2 row_count=2
+++android.widget.ListView collection item_count=2 row_count=2
 ++++android.view.View collection_item name='Term'
 ++++android.view.View role_description='definition' name='Description'
-++android.view.View role_description='definition' name='Definition'
+++android.view.View role_description='definition' name='Definition'
\ No newline at end of file

content/test/data/accessibility/html/dt-expected-android.txt

 android.webkit.WebView focusable focused scrollable
-++android.widget.ListView collection hierarchical item_count=2 row_count=2
+++android.widget.ListView collection item_count=2 row_count=2
 ++++android.view.View collection_item name='Coffee'
-++++android.view.View role_description='definition' name='Black hot drink'
+++++android.view.View role_description='definition' name='Black hot drink'
\ No newline at end of file

content/test/data/accessibility/html/li-expected-android.txt

 android.webkit.WebView focusable focused scrollable
-++android.widget.ListView collection hierarchical item_count=3 row_count=3
+++android.widget.ListView collection item_count=3 row_count=3
 ++++android.view.View collection_item
 ++++++android.view.View name='• '
 ++++++android.view.View name='Item 1'

content/test/data/accessibility/html/list-expected-android.txt

 android.webkit.WebView focusable focused scrollable
-++android.widget.ListView collection hierarchical item_count=3 row_count=3
+++android.widget.ListView collection item_count=3 row_count=3
 ++++android.view.View collection_item
 ++++++android.view.View name='• '
 ++++++android.view.View name='tic'
@@ -9,7 +9,7 @@ android.webkit.WebView focusable focused scrollable
 ++++android.view.View collection_item item_index=2 row_index=2
 ++++++android.view.View name='• '
 ++++++android.view.View name='toe'
-++android.widget.ListView collection hierarchical item_count=5 row_count=5
+++android.widget.ListView collection item_count=5 row_count=5
 ++++android.view.View collection_item name='tic'
 ++++android.view.View name=' '
 ++++android.view.View collection_item name='tac' item_index=1 row_index=2

content/test/data/accessibility/html/nestedlist-expected-android.txt

+android.webkit.WebView focusable focused scrollable
+++android.view.View name='This is a multi-leveled list'
+++android.widget.ListView collection hierarchical item_count=4 row_count=4
+++++android.view.View collection_item
+++++++android.view.View name='1. '
+++++++android.view.View name='Sports'
+++++++android.widget.ListView collection hierarchical item_count=2 row_count=2
+++++++++android.view.View collection_item
+++++++++++android.view.View name='1. '
+++++++++++android.view.View name='Tennis'
+++++++++android.view.View collection_item item_index=1 row_index=1
+++++++++++android.view.View name='2. '
+++++++++++android.view.View name='basketball'
+++++android.view.View collection_item item_index=1 row_index=1
+++++++android.view.View name='2. '
+++++++android.view.View name='Books'
+++++++android.widget.ListView collection hierarchical item_count=3 row_count=3
+++++++++android.view.View collection_item
+++++++++++android.view.View name='1. '
+++++++++++android.view.View name='Oliver Twist'
+++++++++android.view.View collection_item item_index=1 row_index=1
+++++++++++android.view.View name='2. '
+++++++++++android.view.View name='Kindred'
+++++++++android.view.View collection_item item_index=2 row_index=2
+++++++++++android.view.View name='3. '
+++++++++++android.view.View name='The Promise of Sleep'
+++++android.view.View collection_item item_index=2 row_index=2
+++++++android.view.View name='3. '
+++++++android.view.View name='Recipes'
+++++android.widget.ListView collection hierarchical

content/test/data/accessibility/html/nestedlist.html

+<p> This is a multi-leveled list </p>
+<ol>
+  <li> Sports
+    <ol>
+      <li> Tennis </li>
+      <li> basketball </li>
+    </ol>
+  </li>
+  <li> Books
+    <ol>
+      <li> Oliver Twist </li>
+      <li> Kindred </li>
+      <li> The Promise of Sleep </li>
+    </ol>
+  </li>
+  <li> Recipes </li>
+    <ol>
+    </ol>
+</ol>

content/test/data/accessibility/html/ol-expected-android.txt

 android.webkit.WebView focusable focused scrollable
-++android.widget.ListView collection hierarchical item_count=3 row_count=3
+++android.widget.ListView collection item_count=3 row_count=3
 ++++android.view.View collection_item
 ++++++android.view.View name='1. '
 ++++++android.view.View name='Chrome'
@@ -9,7 +9,7 @@ android.webkit.WebView focusable focused scrollable
 ++++android.view.View collection_item item_index=2 row_index=2
 ++++++android.view.View name='3. '
 ++++++android.view.View name='IE'
-++android.widget.ListView collection hierarchical item_count=3 row_count=3
+++android.widget.ListView collection item_count=3 row_count=3
 ++++android.view.View collection_item
 ++++++android.view.View name='10. '
 ++++++android.view.View name='Android'

ui/accessibility/ax_role_properties.cc

@@ -333,4 +333,14 @@ bool IsUIASelectable(const ax::mojom::Role role) {
   }
 }
 
+bool IsStaticList(const ax::mojom::Role role) {
+  switch (role) {
+    case ax::mojom::Role::kList:
+    case ax::mojom::Role::kDescriptionList:
+      return true;
+    default:
+      return false;
+  }
+}
+
 }  // namespace ui

ui/accessibility/ax_role_properties.h

@@ -83,6 +83,8 @@ AX_EXPORT bool SupportsToggle(const ax::mojom::Role role);
 // Automation.
 AX_EXPORT bool IsUIASelectable(const ax::mojom::Role role);
 
+AX_EXPORT bool IsStaticList(const ax::mojom::Role role);
+
 }  // namespace ui
 
 #endif  // UI_ACCESSIBILITY_AX_ROLE_PROPERTIES_H_