Placeholder text now uses its parent's readonly attribute.

Without this change, placeholder's static text is considered to be
Read-Only. This would be confusing to AT users.

With this change, if a node is queried for UIA_IsReadOnlyAttributeId,
we determine if the node is placeholder text. If so, the read-only
value exposed to UIA should match the read-only value of the parent.

Bug: 1017457
Change-Id: I79c41adaeccfd4a8173ab5a6d89c8cde1f6a0477
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1877308Reviewed-by: Kurt Catti-Schmidt <kschmi@microsoft.com>
Commit-Queue: Jacques Newman <janewman@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#709253}

ui/accessibility/platform/ax_platform_node_textrangeprovider_win_unittest.cc

@@ -3321,10 +3321,60 @@ TEST_F(AXPlatformNodeTextRangeProviderTest,
                                        0xDEADC0DEU);
   list_item2_text_data.SetName("list item 2");
 
+  ui::AXNodeData input_text_data;
+  input_text_data.id = 12;
+  input_text_data.role = ax::mojom::Role::kTextField;
+  input_text_data.AddState(ax::mojom::State::kEditable);
+  input_text_data.AddIntAttribute(
+      ax::mojom::IntAttribute::kNameFrom,
+      static_cast<int>(ax::mojom::NameFrom::kPlaceholder));
+  input_text_data.AddStringAttribute(ax::mojom::StringAttribute::kPlaceholder,
+                                     "placeholder2");
+  input_text_data.AddIntAttribute(ax::mojom::IntAttribute::kBackgroundColor,
+                                  0xDEADBEEFU);
+  input_text_data.AddIntAttribute(ax::mojom::IntAttribute::kColor, 0xDEADC0DEU);
+  input_text_data.AddBoolAttribute(ax::mojom::BoolAttribute::kEditableRoot,
+                                   true);
+  input_text_data.SetName("placeholder");
+  input_text_data.child_ids = {13};
+
+  ui::AXNodeData placeholder_text_data;
+  placeholder_text_data.id = 13;
+  placeholder_text_data.role = ax::mojom::Role::kStaticText;
+  placeholder_text_data.AddIntAttribute(
+      ax::mojom::IntAttribute::kBackgroundColor, 0xDEADBEEFU);
+  placeholder_text_data.AddIntAttribute(ax::mojom::IntAttribute::kColor,
+                                        0xDEADC0DEU);
+  placeholder_text_data.SetName("placeholder");
+
+  ui::AXNodeData input_text_data2;
+  input_text_data2.id = 14;
+  input_text_data2.role = ax::mojom::Role::kTextField;
+  input_text_data2.AddState(ax::mojom::State::kEditable);
+  input_text_data2.AddStringAttribute(ax::mojom::StringAttribute::kPlaceholder,
+                                      "placeholder2");
+  input_text_data2.AddIntAttribute(ax::mojom::IntAttribute::kBackgroundColor,
+                                   0xDEADBEEFU);
+  input_text_data2.AddIntAttribute(ax::mojom::IntAttribute::kColor,
+                                   0xDEADC0DEU);
+  input_text_data2.AddBoolAttribute(ax::mojom::BoolAttribute::kEditableRoot,
+                                    true);
+  input_text_data2.SetName("foo");
+  input_text_data2.child_ids = {15};
+
+  ui::AXNodeData placeholder_text_data2;
+  placeholder_text_data2.id = 15;
+  placeholder_text_data2.role = ax::mojom::Role::kStaticText;
+  placeholder_text_data2.AddIntAttribute(
+      ax::mojom::IntAttribute::kBackgroundColor, 0xDEADBEEFU);
+  placeholder_text_data2.AddIntAttribute(ax::mojom::IntAttribute::kColor,
+                                         0xDEADC0DEU);
+  placeholder_text_data2.SetName("placeholder2");
+
   ui::AXNodeData root_data;
   root_data.id = 1;
   root_data.role = ax::mojom::Role::kRootWebArea;
-  root_data.child_ids = {2, 3, 5, 7};
+  root_data.child_ids = {2, 3, 5, 7, 12, 14};
 
   ui::AXTreeUpdate update;
   ui::AXTreeData tree_data;
@@ -3343,6 +3393,10 @@ TEST_F(AXPlatformNodeTextRangeProviderTest,
   update.nodes.push_back(list_item_text_data);
   update.nodes.push_back(list_item2_data);
   update.nodes.push_back(list_item2_text_data);
+  update.nodes.push_back(input_text_data);
+  update.nodes.push_back(placeholder_text_data);
+  update.nodes.push_back(input_text_data2);
+  update.nodes.push_back(placeholder_text_data2);
 
   Init(update);
   AXNodePosition::SetTree(tree_.get());
@@ -3359,6 +3413,10 @@ TEST_F(AXPlatformNodeTextRangeProviderTest,
   AXNode* list_item_text_node = list_item_node->children()[0];
   AXNode* list_item2_node = list_node->children()[1];
   AXNode* list_item2_text_node = list_item2_node->children()[0];
+  AXNode* input_text_node = root_node->children()[4];
+  AXNode* placeholder_text_node = input_text_node->children()[0];
+  AXNode* input_text_node2 = root_node->children()[5];
+  AXNode* placeholder_text_node2 = input_text_node2->children()[0];
 
   ComPtr<ITextRangeProvider> document_range_provider;
   GetTextRangeProviderFromTextNode(document_range_provider, root_node);
@@ -3376,6 +3434,14 @@ TEST_F(AXPlatformNodeTextRangeProviderTest,
   GetTextRangeProviderFromTextNode(list_item2_text_range_provider,
                                    list_item2_text_node);
 
+  ComPtr<ITextRangeProvider> placeholder_text_range_provider;
+  GetTextRangeProviderFromTextNode(placeholder_text_range_provider,
+                                   placeholder_text_node);
+
+  ComPtr<ITextRangeProvider> placeholder_text_range_provider2;
+  GetTextRangeProviderFromTextNode(placeholder_text_range_provider2,
+                                   placeholder_text_node2);
+
   base::win::ScopedVariant expected_variant;
 
   // SkColor is ARGB, COLORREF is 0BGR
@@ -3461,6 +3527,16 @@ TEST_F(AXPlatformNodeTextRangeProviderTest,
                               UIA_IsReadOnlyAttributeId, expected_variant);
   expected_variant.Reset();
 
+  expected_variant.Set(false);
+  EXPECT_UIA_TEXTATTRIBUTE_EQ(placeholder_text_range_provider,
+                              UIA_IsReadOnlyAttributeId, expected_variant);
+  expected_variant.Reset();
+
+  expected_variant.Set(false);
+  EXPECT_UIA_TEXTATTRIBUTE_EQ(placeholder_text_range_provider2,
+                              UIA_IsReadOnlyAttributeId, expected_variant);
+  expected_variant.Reset();
+
   expected_variant.Set(true);
   EXPECT_UIA_TEXTATTRIBUTE_EQ(text_range_provider, UIA_IsSubscriptAttributeId,
                               expected_variant);

ui/accessibility/platform/ax_platform_node_win.cc

@@ -4355,6 +4355,14 @@ HRESULT AXPlatformNodeWin::GetTextAttributeValue(TEXTATTRIBUTEID attribute_id,
                            : VARIANT_FALSE;
       break;
     case UIA_IsReadOnlyAttributeId:
+      // Placeholder text should return the enclosing element's read-only value.
+      if (IsPlaceholderText()) {
+        AXPlatformNodeWin* parent_platform_node =
+            static_cast<AXPlatformNodeWin*>(
+                FromNativeViewAccessible(GetParent()));
+        return parent_platform_node->GetTextAttributeValue(attribute_id,
+                                                           result);
+      }
       V_VT(result) = VT_BOOL;
       V_BOOL(result) =
           (GetData().GetRestriction() == ax::mojom::Restriction::kReadOnly ||
@@ -7109,6 +7117,17 @@ bool AXPlatformNodeWin::IsAncestorComboBox() {
   return parent->IsAncestorComboBox();
 }
 
+bool AXPlatformNodeWin::IsPlaceholderText() const {
+  if (GetData().role != ax::mojom::Role::kStaticText)
+    return false;
+  AXPlatformNodeWin* parent =
+      static_cast<AXPlatformNodeWin*>(FromNativeViewAccessible(GetParent()));
+  // Static text nodes are always expected to have a parent.
+  DCHECK(parent);
+  return (parent->IsPlainTextField() || parent->IsRichTextField()) &&
+         parent->HasStringAttribute(ax::mojom::StringAttribute::kPlaceholder);
+}
+
 bool AXPlatformNodeWin::IsHyperlink() {
   int32_t hyperlink_index = -1;
   AXPlatformNodeWin* parent =

ui/accessibility/platform/ax_platform_node_win.h

@@ -1275,6 +1275,8 @@ class AX_EXPORT __declspec(uuid("26f5641a-246d-457b-a96d-07f3fae6acf2"))
 
   bool IsAncestorComboBox();
 
+  bool IsPlaceholderText() const;
+
   // Helper method for getting the horizontal scroll percent.
   double GetHorizontalScrollPercent();